1,3-dichlorobenzene-containing metal degreasing cleaning agent and preparation method thereof

Abstract

The present application belongs to the field of metal surface treatment and industrial cleaning technology, and provides a kind of 1,3-dichlorobenzene metal degreasing cleaning agent and its preparation method, the present application is prepared by the surface condensation technology of 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanometer composite intermediate with β-cyclodextrin inclusion and siloxane sol-gel, with oleic acid diethylene triamine imidazoline corrosion inhibitor, propylene carbonate cosolvent, sodium xylene sulfonate dispersant and D-sodium gluconate chelating agent, complex in alkaline aqueous phase (pH 8.2-9.5), effectively solve the structural contradiction of high load packaging and aqueous gel stability, VOC compliance requirements and degreasing efficiency functional contradiction and the contradiction of siloxane shell hydrolysis durability under alkaline system, has wide application value in the field of automobile manufacturing and precision machinery and other industrial metal parts degreasing cleaning.

Description

Technical Field

[0001] This invention relates to the field of industrial cleaning and metal surface treatment, specifically to a 1,3-dichlorobenzene metal degreasing cleaning agent and its preparation method. Background Technology

[0002] In high-end manufacturing sectors such as aerospace, automotive manufacturing, precision machinery, electronic hardware, and rail transportation, metal workpieces inevitably accumulate various contaminants on their surfaces during machining, assembly, storage, and transportation, including mineral grease, rust-preventive oil, stamping lubricating oil, and metal soap. If these contaminants are not thoroughly removed before subsequent processes such as coating, electroplating, welding, and bonding, they will directly lead to quality defects such as reduced coating adhesion, uneven plating, increased weld porosity, and bonding failure, severely restricting product reliability and lifespan. Therefore, metal degreasing and cleaning is an indispensable key process in high-end manufacturing. With the deepening of green manufacturing and clean production policies, the industrial cleaning industry is facing increasingly stringent volatile organic compound (VOC) emission limits and safe operating procedures. Especially in large-scale continuous production scenarios using closed-loop cleaning equipment, cleaning agents must not only possess efficient penetration and dissolution capabilities for complex oil films but also consider the long-term colloidal stability of the aqueous dispersion system, the corrosion inhibition and protection performance of the metal substrate, compliance with low VOCs and inherent safety due to high flash points, as well as broad compatibility with various metal substrates. Under the aforementioned multiple performance constraints, the development of novel, efficient, environmentally friendly, and stable water-based metal degreasing and cleaning agents has significant technical value and engineering implications.

[0003] Currently, metal degreasing and cleaning agents used in industrial production can be mainly divided into two categories: organic solvent-based and water-based. Traditional organic solvent-based cleaning agents, represented by trichloroethylene, tetrachloroethylene, and dichloromethane, were once widely used due to their strong oil-dissolving ability. However, these chlorinated hydrocarbon solvents are highly toxic, have high VOC content, and are highly volatile, and have been subject to strict environmental regulations or even bans in many countries. The development of alternatives has become an industry consensus. To address these shortcomings, researchers have attempted to introduce less reactive but still relatively oil-soluble chlorinated aromatic hydrocarbons (such as 1,3-dichlorobenzene) to replace highly toxic aliphatic chlorinated hydrocarbons, and to disperse them in an aqueous system through inclusion or microencapsulation technology to control their free volatilization. For example, Chinese patent CN119639530A discloses a water-based flux cleaner for integration, but it has shortcomings such as insufficient dispersion stability of the active solvent in the aqueous phase, high VOC content in the system, and failure to perform nanoscale encapsulation of the chlorinated solvent, resulting in a closed-cup flash point that does not meet industrial safety operation requirements, which limits its further application. Summary of the Invention

[0004] The purpose of this invention is to provide a 1,3-dichlorobenzene metal degreasing cleaning agent and its preparation method, thereby solving three major technical problems in the current field of metal degreasing cleaning: the structural contradiction between high-load encapsulation and the stability of aqueous colloidal phases; the functional contradiction between low VOC compliance requirements and the degreasing efficiency of active components at the interface; and the limitation imposed by alkaline buffer systems on the hydrolytic durability of siloxane encapsulation shells.

[0005] This invention employs a "dual-core synergistic effect" formulation design concept, using a 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate as the active degreasing core and diethylenetriamine imidazoline oleate as the interfacial corrosion inhibitor and dispersion stabilizing composite functional component. The two components exert a deep synergistic effect in the system. The nanocomposite intermediate, through the dual constraint of β-cyclodextrin molecular inclusion and siloxane shell, immobilizes 1,3-dichlorobenzene in a controlled manner within nanoparticles, triggering directional release at the oil-water interface for highly efficient degreasing. The amphiphilic molecular structure of diethylenetriamine imidazoline oleate provides coordination adsorption protection on the metal surface and reduces the interfacial aggregation tendency of nanoparticles in the aqueous phase, acting as a stabilizer to promote particle enrichment and migration to the oil film interface. The two components mutually promote each other, enabling the cleaning system to surpass the combined contribution of either individual component in both degreasing efficiency and metal corrosion protection.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A 1,3-dichlorobenzene metal degreasing cleaning agent, based on 100 parts by weight of the total weight of the cleaning agent, comprises the following components:

[0008] 0.6-5.0 parts by weight of 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate;

[0009] 0.6-4.0 parts by weight of diethylenetriamine imidazoline oleate;

[0010] 3.0-12.0 parts by weight of propylene carbonate;

[0011] Sodium xylenesulfonate 1.0-6.0 parts by weight;

[0012] Sodium D-gluconate 0.5-4.0 parts by weight;

[0013] Sodium carbonate 0.1-1.2 parts by weight;

[0014] Add the remaining deionized water to a total of 100 parts by weight.

[0015] The 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate is prepared from 1,3-dichlorobenzene, β-cyclodextrin, tetraethyl silicate, and 3-aminopropyltriethoxysilane. The 1,3-dichlorobenzene loading in the nanocomposite intermediate is 18.0-35.0 wt% based on the dry weight of the nanocomposite intermediate, as determined by solvent extraction-gas chromatography. The median particle size D50 is 80-180 nm, as determined by dynamic light scattering. The actual 1,3-dichlorobenzene content in the cleaning agent is 0.11-1.75 wt%, as determined by gas chromatography, and the pH value is 8.2-9.5.

[0016] Furthermore, the 1,3-dichlorobenzene-β-cyclodextrin encapsulating slurry used in the preparation of the nanocomposite intermediate was prepared according to the following steps:

[0017] A1. Mix 100-220 parts by weight of β-cyclodextrin, 600-1200 parts by weight of deionized water and 200-600 parts by weight of ethanol with a volume fraction of 95-99.9 vol%, and stir at 35-50℃ and 300-800 r / min for 20-40 min.

[0018] A2. Add 20-80 parts by weight of 1,3-dichlorobenzene dropwise to the system obtained in step A1 at 35-50℃ over 10-60 min, and disperse under high shear at 2000-5000 r / min in air for 20-60 min;

[0019] A3. Keep the system at 35-50℃ and 300-800r / min and continue stirring for 30-120min. When no independent oil phase is precipitated after the system has stood for 30min, 1,3-dichlorobenzene-β-cyclodextrin-encapsulated slurry is obtained.

[0020] Furthermore, the nanocomposite intermediate is prepared according to the following steps:

[0021] B1. Add 10-40 parts by weight of tetraethyl silicate and 5-20 parts by weight of 3-aminopropyltriethoxysilane to the 1,3-dichlorobenzene-β-cyclodextrin coating slurry.

[0022] B2. Add ammonia water with a mass fraction of 20-30 wt% by drop while stirring until the pH of the system stabilizes at 8.5-10.5. Carry out the condensation reaction for 1-3 hours at 40-60℃ and 300-800 r / min.

[0023] B3. After aging at 40-60℃ for 4-12 hours, the product is separated by centrifugation or filtration. The centrifugation force is 5000-20000g and the centrifugation time is 5-60 minutes. Alternatively, the filter material used for filtration has a pore size of 0.1-1.0 μm. The resulting solid is washed 1-3 times with ethanol and then with deionized water, with each wash volume being 5-20 times the mass of the solid. Subsequently, it is vacuum dried at 35-45℃ and an absolute pressure of 0.005-0.030 MPa for 4-12 hours to obtain a powdered 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate.

[0024] B4. The median particle size D50 of the obtained nanocomposite intermediate was 80-180 nm, which was determined by dynamic light scattering method; and the 1,3-dichlorobenzene loading was 18.0-35.0 wt% based on the dry basis of the nanocomposite intermediate, which was determined by solvent extraction-gas chromatography.

[0025] Furthermore, the diethylenetriamine imidazoline oleate is prepared according to the following steps:

[0026] C1. Add 100-130 parts by weight of oleic acid and 33.2-47.5 parts by weight of diethylenetriamine to a reaction vessel, and ensure that the actual amount of each component meets the requirement that the molar ratio of oleic acid to diethylenetriamine is 1.00-1.10:1.00;

[0027] C2. Heat to 140-160℃ under a nitrogen atmosphere and react for 1-2 hours;

[0028] C3. Continue heating to 180-220℃ and react for 2-6 hours at an absolute pressure of 0.010-0.030 MPa;

[0029] C4. When the product acid value is 3-10 mg KOH / g and the moisture content is not higher than 0.50 wt%, stop the reaction, cool to 50-70℃ and discharge to obtain diethylenetriamine imidazoline oleate.

[0030] Furthermore, the cleaning agent, as measured by the method specified in GB38508-2020, has a volatile organic compound content of no more than 300 g / L, a closed-cup flash point of no less than 65°C as measured by GB / T21615-2008, a median particle size D50 of 100-180 nm, measured by dynamic light scattering method, and shows no visible stratification after being placed at 40°C for 7 days. Moreover, the cleaning agent does not contain dichloromethane, trichloromethane, trichloroethylene, or tetrachloroethylene in its formulation.

[0031] As a concept of this invention, a formulation design employing dual-core synergistic compounding and multifunctional excipient balancing is adopted, primarily to enhance the degreasing efficiency and long-term stability of 1,3-dichlorobenzene-containing metal degreasing cleaning agents in aqueous systems. In this technical solution, the core active component, the 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate, achieves molecular-level inclusion of 1,3-dichlorobenzene through β-cyclodextrin cavities and synergistic constraint with the condensation shell layer on the surface of the siloxane sol-gel. This significantly reduces the vapor pressure of free 1,3-dichlorobenzene while simultaneously immobilizing the active degreasing component in controlled manner within nanostructured particles with a diameter of 80-180 nm, enabling the cleaning agent to simultaneously achieve the dual compliance goals of low VOC and high flash point. The siloxane shell introduces hydrophilic silanol groups onto the particle surface, providing a dual stabilization mechanism of electrostatics and steric hindrance. The synergistic effect of the nanocomposite intermediate and diethylenetriamine imidazoline further enhances the dispersion stability of the nanoparticles in an alkaline aqueous phase. The amphiphilic structure of the imidazoline reduces the effective aggregation driving force between particles and guides the nanoparticles to migrate directionally towards the oil film interface through enrichment at the oil-water interface. Under mechanical shear, it triggers the controlled interfacial release of 1,3-dichlorobenzene, achieving efficient dissolution and penetration of oils. The imidazoline ring in diethylenetriamine imidazoline forms a monomolecular-level protective film on the cleaned metal surface through coordination adsorption, providing immediate corrosion inhibition protection after cleaning. Propylene carbonate reduces the interfacial tension of the system and improves wettability and penetration through the polar solvent effect; sodium xylenesulfonate acts as a water-soluble growth promoter to improve the compatibility of the hydrophobic components in the aqueous phase; sodium D-gluconate inhibits ion-induced nanoparticle aggregation by chelating hardness metal ions in water; and sodium carbonate provides an alkaline pH buffer while assisting in the saponification of oils. The components complement and synergize at the functional level, giving the cleaning agent significant overall advantages in three dimensions: degreasing efficiency, corrosion inhibition and protection, and storage stability.

[0032] This invention also discloses a method for preparing a 1,3-dichlorobenzene metal degreasing cleaning agent, comprising the following steps:

[0033] S1. Provides nanocomposite intermediates;

[0034] S2. Provides diethylenetriamine imidazoline oleate;

[0035] S3. Stir 40-70 parts by weight of deionized water, 5-15 parts by weight of propylene carbonate, 2-8 parts by weight of sodium xylenesulfonate, 1-5 parts by weight of sodium D-gluconate and 0.2-1.5 parts by weight of sodium carbonate at 40-55℃ for 20-40 min until no undissolved matter is visible to the naked eye; add 1-6 parts by weight of diethylenetriamine imidazoline oleate provided in step S2, and stir at 40-55℃ and 800-1500 r / min for 15-30 min.

[0036] S4. Add 5-25 parts by weight of the nanocomposite intermediate provided in step S1 to the system obtained in step S3 and disperse it; when the pH of the system is lower than 8.2, add 5-15 wt% sodium carbonate aqueous solution to adjust the pH to 8.2-9.5; when the pH of the system is higher than 9.5, add 5-15 wt% citric acid aqueous solution to lower it to 8.2-9.5; let it stand and mature to obtain a pre-concentrated solution with a median particle size D50 of 100-220 nm, wherein the median particle size D50 is measured by dynamic light scattering method; mix the pre-concentrated solution with deionized water to obtain the 1,3-dichlorobenzene metal degreasing cleaning agent.

[0037] Furthermore, after step S4, the system is allowed to stand at 20-30°C for 12-24 hours and then filtered through a 50-200 mesh filter before being filled.

[0038] Furthermore, after step S4, the method further includes using the obtained cleaning agent in undiluted form or diluting it with deionized water at a weight ratio of 1:0.5 to 1:4 before use.

[0039] Furthermore, in step S4, the dispersion speed is 1500-3000 r / min, the dispersion time is 20-60 min, and the maturation time is 12-24 h.

[0040] Furthermore, in step S4, when the nanocomposite intermediate is added and dispersed, the dispersion temperature is 40-55℃.

[0041] Furthermore, when the median particle size D50 of the nanocomposite intermediate and the cleaning agent is determined by dynamic light scattering, the sample is diluted with deionized water to a solid content of 0.01-0.10 wt% before the determination, and the determination temperature is 25℃.

[0042] Furthermore, the loading of 1,3-dichlorobenzene in the nanocomposite intermediate can be further verified by thermogravimetric analysis. The determination conditions are: based on the dry basis mass of the nanocomposite intermediate, under nitrogen atmosphere, with a heating rate of 10℃ / min, and expressed as the mass loss in the range of 200-250℃.

[0043] Furthermore, in step S4, the dispersion temperature is 40-55℃.

[0044] Furthermore, during the stability evaluation, 50 mL of sample was placed in a transparent stoppered glass bottle and placed at 40°C for 7 days to observe whether visible stratification occurred.

[0045] As another aspect of this invention, a preparation method combining stepwise prefabrication, ordered feeding, and bidirectional intelligent pH control is designed to enhance the batch-to-batch consistency, nano-dispersion stability, and engineering feasibility of the prepared 1,3-dichlorobenzene metal degreasing cleaning agent. In the preparation method, the independent prefabrication steps (S1, S2) of the nanocomposite intermediate and diethylenetriamine imidazoline oleate ensure the quality controllability of each of the two core functional components. In step S3, the feeding strategy of dissolving the aqueous phase adjuvant before the imidazoline avoids premature deactivation of the active component in a high-concentration electrolyte environment. In step S4, a bidirectional pH control mechanism based on real-time pH monitoring using sodium carbonate aqueous solution (pH increase) and citric acid aqueous solution (pH decrease) precisely maintains the system pH within the functional safety window of 8.2-9.5. While meeting the requirements for maintaining the effective form of the corrosion inhibitor, this method controls the hydrolysis driving force of the siloxane encapsulation layer within an acceptable range, fundamentally mitigating the negative impact of alkaline environments on the durability of the particle structure. The combination of dispersion process parameters (1500-3000 r / min, 20-60 min, 40-55℃) and aging conditions (12-24 h, 20-30℃) in S4 ensures that the nanocomposite particles undergo sufficient deagglomeration and interfacial hydrophilic reconstruction in the final system, forming a stable cleaning agent dispersion system with a D50 of 100-180 nm. Subsequent filtration effectively removes residual aggregates, ensuring batch-to-batch consistency in product particle size distribution. This method has a clear process path, with key parameters precisely defined, demonstrating good industrial operability and reproducibility.

[0046] The core function of the 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate lies in the controlled introduction of 1,3-dichlorobenzene into an aqueous system at the nanoscale. The β-cyclodextrin cavity achieves molecular-level locking of 1,3-dichlorobenzene through van der Waals forces and hydrophobic interactions, effectively suppressing the volatilization of free state and thus meeting VOC compliance requirements. The outer siloxane shell provides mechanical encapsulation protection through a Si-O-Si bond network and exhibits abundant Si-OH groups on the particle surface, endowing the particles with hydrophilicity to maintain the stability of aqueous dispersion. During degreasing, after the nanoparticles migrate to the oil-water interface, they are driven by interfacial shear forces and the oil solvent environment, triggering interfacial shifts in the β-cyclodextrin inclusion equilibrium. This allows 1,3-dichlorobenzene to be directionally enriched at the oil film interface, exerting its dissolving and penetrating effects. Regarding diethylenetriamine imidazoline oleate, the two nitrogen atoms in its imidazoline ring can form strong coordination bonds with unsaturated sites on the surfaces of metals such as iron and copper, forming a hydrophobic monomolecular corrosion inhibitor film on the metal surface, effectively blocking the corrosion of the metal substrate by corrosive media. Simultaneously, the lipophilic tail of its long carbon chain can insert into the oil film, reducing the adhesion between the oil film and the metal interface, synergistically enhancing the removal efficiency of grease. The synergistic effect of the two in the composite system is manifested as follows: the amphiphilic structure of diethylenetriamine imidazoline oleate acts as a natural surfactant, not only reducing the effective aggregation tendency of nanocomposite particles in the aqueous phase, but also guiding the particles to enrich and migrate directionally towards the oil film interface, thereby amplifying the interfacial degreasing efficiency of the nanocomposite intermediate; at the same time, the efficient distribution of nanocomposite particles at the interface further enhances the spreading and coverage of diethylenetriamine imidazoline oleate on the metal surface. The two mutually promote each other, resulting in a significant improvement in both degreasing efficiency and corrosion inhibition performance compared to single components.

[0047] Beneficial technical effects

[0048] 1. This invention employs a dual encapsulation strategy of β-cyclodextrin molecule inclusion and siloxane sol-gel surface condensation, enabling the loading of 1,3-dichlorobenzene in the nanocomposite intermediate to reach 18.0-35.0 wt%, far exceeding the loading level of traditional inclusion technologies. Simultaneously, the siloxane shell imparts hydrophilic surface properties to the particles, stabilizing the median particle size D50 of the nanoparticles in the cleaning agent at 100-180 nm. No visible delamination is observed after 7 days of storage at 40°C. This invention achieves synergistic satisfaction of two opposing performance objectives: high active component loading and long-term colloidal stability in the aqueous phase.

[0049] 2. The nano-encapsulation strategy of 1,3-dichlorobenzene in this invention significantly reduces the vapor partial pressure of free 1,3-dichlorobenzene, ensuring that the volatile organic compound content of the cleaning agent is no higher than 300 g / L, meeting the requirements of GB38508-2020, and the closed-cup flash point is no lower than 65℃, meeting the requirements of GB / T21615-2008. At the same time, through the controlled release mechanism of nanoparticles at the oil-water interface, the highly efficient dissolving and penetrating ability of 1,3-dichlorobenzene for heavy oils is retained while meeting regulatory compliance requirements, fundamentally solving the functional contradiction that "the stricter the compliance control, the weaker the degreasing efficiency".

[0050] 3. In this invention, diethylenetriamine imidazoline oleate forms a dense monomolecular protective adsorption film on the metal substrate surface through strong coordination bonding between the nitrogen atom on the imidazoline ring and the metal surface. Under alkaline aqueous conditions (pH 8.2-9.5), it effectively inhibits the corrosion and weight loss of multi-metal substrates such as iron, copper, and aluminum. It can provide necessary immediate corrosion inhibition protection for the workpiece during the process interval between cleaning and subsequent surface treatment processes, and avoid the occurrence of rust after cleaning.

[0051] 4. This invention maintains a buffer system with a pH of 8.2-9.5 through the synergistic effect of multifunctional adjuvants, and inhibits the aggregation of nanoparticles induced by polyvalent metal ions by utilizing the chelating effect of sodium D-gluconate on hardness metal ions such as calcium and magnesium in water; at the same time, it controls the upper limit of alkaline pH below 9.5, keeping the hydrolysis driving force on the siloxane shell within an acceptable range, and establishes an effective chemical compatibility balance between maintaining corrosion inhibition function and the durability of the encapsulation structure, thus giving the product good shelf-life stability.

[0052] 5. Safe and environmentally friendly, free of highly toxic halogenated solvents: The formulation of this invention does not contain highly toxic halogenated hydrocarbons such as dichloromethane, trichloromethane, trichloroethylene, and tetrachloroethylene. It uses 1,3-dichlorobenzene nanocomposite intermediate, which is compliant with VOCs, as the only chlorine-containing active ingredient. Combined with a water-based system design with a high closed-cup flash point (≥65℃), it significantly reduces occupational health and fire safety risks during use, and is conducive to replacing traditional highly toxic halogenated hydrocarbon solvent-based cleaning agents in the field of industrial metal cleaning. Attached Figure Description

[0053] Figure 1 The particle size stability time curves of the 1,3-dichlorobenzene metal degreasing cleaning agents prepared in Examples 1 to 4 and Comparative Examples 2, 5 and 9 under accelerated aging conditions at 40°C are shown.

[0054] Figure 2 The pH-colloidal stability-carbon steel corrosion rate coupling curves are for the 1,3-dichlorobenzene metal degreasing cleaning agents prepared in Examples 1 to 4 and Comparative Examples 7 and 8.

[0055] Figure 3 Field emission scanning electron microscope (FESEM) image of the 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate powder prepared in Example 1.

[0056] Figure 4 Macroscopic optical photographs of the 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate powder prepared in Example 1 and the 1,3-dichlorobenzene metal degreasing cleaning agent. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0058] Example 1

[0059] This embodiment provides a degreasing cleaning agent containing 1,3-dichlorobenzene metal, wherein the dosage of each component is selected in the middle range of each parameter range, and the preparation steps are as follows.

[0060] Preparation of diethylenetriamine imidazoline oleate: C1. Add 115 parts by weight of oleic acid and 40.0 parts by weight of diethylenetriamine to a reaction vessel, ensuring that the actual amount of each component meets the molar ratio of oleic acid to diethylenetriamine of 1.05:1.00; C2. Heat to 150°C under a nitrogen atmosphere and react at this temperature for 1.5 h; C3. Continue to heat to 200°C and react at an absolute pressure of 0.020 MPa for 4 h; C4. Stop the reaction when the product acid value is 6.0 mg KOH / g and the moisture content is 0.25 wt% (not higher than 0.50 wt%), cool to 60°C and discharge to obtain diethylenetriamine imidazoline oleate of this embodiment.

[0061] Preparation of 1,3-dichlorobenzene-β-cyclodextrin-coated slurry: A1. Mix 160 parts by weight of β-cyclodextrin, 900 parts by weight of deionized water, and 400 parts by weight of ethanol (97 vol%), and stir at 42°C and 550 r / min for 30 min; A2. Add 50 parts by weight of 1,3-dichlorobenzene dropwise to the system obtained in step A1 at 42°C over 35 min, and disperse under high shear at 3500 r / min in air for 40 min; A3. Continue stirring the system at 42°C and 550 r / min for 75 min. After the system stands for 30 min, no independent oil phase precipitates, thus obtaining the 1,3-dichlorobenzene-β-cyclodextrin-coated slurry of this embodiment.

[0062] Preparation of 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate: B1. Add 25 parts by weight of tetraethyl silicate and 12 parts by weight of 3-aminopropyltriethoxysilane to the 1,3-dichlorobenzene-β-cyclodextrin encapsulating slurry of this example; B2. Add ammonia water with a mass fraction of 25 wt% by weight dropwise while stirring until the pH of the system stabilizes at 9.5, and carry out a condensation reaction at 50℃ and 550 r / min for 2 h; B3. After aging at 50℃ for another 8 h, centrifuge at a relative centrifugal force of 12000 g and a centrifugation time of 30 min, and discard the supernatant; the obtained solid is washed twice with ethanol and then twice with deionized water, with the volume of the washing liquid each time being 12 times the mass of the obtained solid; then in 4 Vacuum drying at 0℃ and 0.015MPa for 8h yielded the 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate of this embodiment in powder form; B4. The median particle size D50 of the nanocomposite intermediate of this embodiment was determined by dynamic light scattering (the sample was diluted with deionized water to a solid content of 0.05wt% before measurement, and the measurement temperature was 25℃), and the result was 130nm; the 1,3-dichlorobenzene loading (based on the dry basis of the nanocomposite intermediate) was determined by solvent extraction-gas chromatography and was 26.0wt%; thermogravimetric analysis was used to assist in confirmation, and the mass loss in the 200-250℃ range under nitrogen atmosphere and heating rate of 10℃ / min was consistent with the result of gas chromatography.

[0063] Preparation of a 1,3-dichlorobenzene metal degreasing cleaning agent: S1. Provide the nanocomposite intermediate prepared in step B3 of this embodiment; S2. Provide the diethylenetriamine imidazoline oleate prepared in step C4 of this embodiment; S3. Stir 81.2 parts by weight of deionized water, 7.5 parts by weight of propylene carbonate, 3.5 parts by weight of sodium xylenesulfonate, 2.2 parts by weight of sodium D-gluconate and 0.6 parts by weight of sodium carbonate at 48°C for 30 min until no visible undissolved matter is found in the system, add 2.2 parts by weight of diethylenetriamine imidazoline oleate provided in step S2, and stir at 48°C and 1100 r / min. Stir for 22 min; S4. Add 2.8 parts by weight of the nanocomposite intermediate provided in step S1 to the system obtained in step S3, disperse at a speed of 2200 r / min for 40 min, and disperse at a temperature of 48℃; monitor the pH value of the system. The pH value in this step is 8.8, which is within the range of 8.2-9.5, and no pH adjustment is required; let stand for 16 h to obtain a pre-concentrated solution with a median particle size D50 of 150 nm (measured by dynamic light scattering method; before measurement, the sample was diluted with deionized water to a solid content of 0.05 wt%, and the measurement temperature was 25℃); mix the pre-concentrated solution of this embodiment with an appropriate amount of deionized water to obtain the 1,3-dichlorobenzene metal degreasing cleaning agent of this embodiment. After step S4, let the system stand at 25℃ for 18 h, filter through a 100-mesh filter, and then fill into bottles. The cleaning agent of this embodiment is used in undiluted form or diluted with deionized water at a weight ratio of 1:2.

[0064] Composition and performance of the cleaning agent: The 1,3-dichlorobenzene metal degreasing cleaning agent prepared in this embodiment, based on 100 parts by weight of the total cleaning agent, contains the following components: 2.8 parts by weight of 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate; 2.2 parts by weight of diethylenetriamine imidazoline oleate; 7.5 parts by weight of propylene carbonate; 3.5 parts by weight of sodium xylenesulfonate; 2.2 parts by weight of sodium D-gluconate; 0.6 parts by weight of sodium carbonate; and 81.2 parts by weight of deionized water. The loading of the 1,3-dichlorobenzene nanocomposite intermediate in this embodiment is 26.0 wt%. Combined with its usage of 2.8 parts by weight in the formulation, the actual content of 1,3-dichlorobenzene in the cleaning agent of this embodiment is calculated to be 2.8 × 26.0% = 0.728 wt%, which is consistent with the results measured by gas chromatography. The cleaning agent in this embodiment has a pH of 8.8; the median particle size D50, measured by dynamic light scattering, is 140 nm (the sample was diluted with deionized water to a solid content of 0.05 wt% before measurement, and the measurement temperature was 25°C); the volatile organic compound content, measured according to GB38508-2020, is not higher than 300 g / L; the closed-cup flash point, measured according to GB / T21615-2008, is not lower than 65°C; 50 mL of sample was placed in a transparent stoppered glass bottle, and after being placed at 40°C for 7 days, no visible stratification was observed. The cleaning agent in this embodiment does not contain dichloromethane, trichloromethane, trichloroethylene, or tetrachloroethylene in its formulation.

[0065] This embodiment is applicable to the daily industrial degreasing of general metal parts such as carbon steel, alloy steel, aluminum alloy and copper alloy. It covers a wide range of industrial scenarios, including pretreatment of automotive stamping parts and castings before painting, removal of medium oil stains before assembly of general machined parts, surface cleaning of precision instrument parts, and pre-cleaning of metal products before rust prevention. It is especially suitable for large-scale production enterprises with high requirements for the stability and batch consistency of cleaning solutions.

[0066] Example 2

[0067] This embodiment provides a 1,3-dichlorobenzene metal degreasing cleaning agent, which aims to improve the comprehensive synergistic degreasing performance of the nanocomposite intermediate and the imidazoline active component. The dosage of both is appropriately increased and matched with a higher 1,3-dichlorobenzene loading. The preparation steps are as follows.

[0068] Preparation of diethylenetriamine imidazoline oleate: C1. Add 125 parts by weight of oleic acid and 42.3 parts by weight of diethylenetriamine to a reaction vessel, ensuring that the actual amount of each component meets the molar ratio of oleic acid to diethylenetriamine of 1.08:1.00; C2. Heat to 155°C under a nitrogen atmosphere and react at this temperature for 1.5 h; C3. Continue to heat to 210°C and react at an absolute pressure of 0.015 MPa for 3 h; C4. Stop the reaction when the product acid value is 5.0 mg KOH / g and the moisture content is 0.20 wt% (not higher than 0.50 wt%), cool to 65°C and discharge to obtain diethylenetriamine imidazoline oleate of this embodiment.

[0069] Preparation of 1,3-dichlorobenzene-β-cyclodextrin-coated slurry: A1. Mix 150 parts by weight of β-cyclodextrin, 750 parts by weight of deionized water, and 350 parts by weight of ethanol (99 vol%), and stir at 45°C and 650 r / min for 25 min; A2. Add 60 parts by weight of 1,3-dichlorobenzene dropwise to the system obtained in step A1 at 45°C over 25 min, and disperse under high shear at 4000 r / min in air for 50 min; A3. Continue stirring the system at 45°C and 650 r / min for 60 min. After the system stands for 30 min, no independent oil phase precipitates, thus obtaining the 1,3-dichlorobenzene-β-cyclodextrin-coated slurry of this embodiment.

[0070] Preparation of 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate: B1. Add 30 parts by weight of tetraethyl silicate and 15 parts by weight of 3-aminopropyltriethoxysilane to the 1,3-dichlorobenzene-β-cyclodextrin encapsulating slurry of this example; B2. Add ammonia water with a mass fraction of 25 wt% by weight dropwise while stirring until the pH of the system stabilizes at 9.8, and carry out a condensation reaction at 55℃ and 650 r / min for 1.5 h; B3. After aging at 55℃ for 6 h, centrifuge at a relative centrifugal force of 15000 g and a centrifugation time of 20 min, and discard the supernatant; the obtained solid is washed twice with ethanol and then twice with deionized water, with the volume of the washing liquid each time being 10 times the mass of the obtained solid; subsequently... The 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate of this embodiment was obtained in powder form after vacuum drying at 42℃ and an absolute pressure of 0.020MPa for 6h. B4. The median particle size D50 of the nanocomposite intermediate of this embodiment was determined by dynamic light scattering (the sample was diluted with deionized water to a solid content of 0.05wt% before the determination, and the determination temperature was 25℃), and the result was 110nm. The loading of 1,3-dichlorobenzene (based on the dry basis of the nanocomposite intermediate) was determined by solvent extraction-gas chromatography and was 29.0wt%. Thermogravimetric analysis was used to assist in the confirmation. Under nitrogen atmosphere and a heating rate of 10℃ / min, the mass loss in the 200-250℃ range was consistent with the result of gas chromatography.

[0071] Preparation of a 1,3-dichlorobenzene metal degreasing cleaning agent: S1. Provide the nanocomposite intermediate prepared in step B3 of this embodiment; S2. Provide the diethylenetriamine imidazoline oleate prepared in step C4 of this embodiment; S3. Stir 80.4 parts by weight of deionized water, 6.0 parts by weight of propylene carbonate, 4.0 parts by weight of sodium xylenesulfonate, 2.8 parts by weight of sodium D-gluconate and 0.5 parts by weight of sodium carbonate at 50°C for 25 min until no visible undissolved matter is found in the system, add 2.8 parts by weight of diethylenetriamine imidazoline oleate provided in step S2, and stir at 50°C and 1300 r / min. Stir for 25 min; S4. Add 3.5 parts by weight of the nanocomposite intermediate provided in step S1 to the system obtained in step S3, disperse at a speed of 2600 r / min for 50 min, and disperse at a temperature of 50℃; monitor the pH value of the system. The pH value in this step is 8.6, which is within the range of 8.2-9.5, and no pH adjustment is required; let stand for 14 h to obtain a pre-concentrated solution with a median particle size D50 of 130 nm (measured by dynamic light scattering method; before measurement, the sample was diluted with deionized water to a solid content of 0.05 wt%, and the measurement temperature was 25℃); mix the pre-concentrated solution of this embodiment with an appropriate amount of deionized water to obtain the 1,3-dichlorobenzene metal degreasing cleaning agent of this embodiment. After step S4, let the system stand at 25℃ for 16 h, filter through an 80-mesh filter, and then fill into bottles. The cleaning agent of this embodiment is used in undiluted form or diluted with deionized water at a weight ratio of 1:1.

[0072] Composition and performance of the cleaning agent: The 1,3-dichlorobenzene metal degreasing cleaning agent prepared in this embodiment, based on 100 parts by weight of the total cleaning agent, contains the following components: 3.5 parts by weight of 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate; 2.8 parts by weight of diethylenetriamine imidazoline oleate; 6.0 parts by weight of propylene carbonate; 4.0 parts by weight of sodium xylenesulfonate; 2.8 parts by weight of sodium D-gluconate; 0.5 parts by weight of sodium carbonate; and 80.4 parts by weight of deionized water. The loading of the 1,3-dichlorobenzene nanocomposite intermediate in this embodiment is 29.0 wt%. Combined with its usage of 3.5 parts by weight in the formulation, the actual content of 1,3-dichlorobenzene in the cleaning agent of this embodiment is calculated to be 3.5 × 29.0% = 1.015 wt%, which is consistent with the results measured by gas chromatography. The cleaning agent in this embodiment has a pH of 8.6; the median particle size D50, measured by dynamic light scattering, is 120 nm (the sample was diluted with deionized water to a solid content of 0.05 wt% before measurement, and the measurement temperature was 25°C); the volatile organic compound content, measured according to GB38508-2020, is not higher than 300 g / L; the closed-cup flash point, measured according to GB / T21615-2008, is not lower than 65°C; 50 mL of sample was placed in a transparent stoppered glass bottle, and after being placed at 40°C for 7 days, no visible stratification was observed. The cleaning agent in this embodiment does not contain dichloromethane, trichloromethane, trichloroethylene, or tetrachloroethylene in its formulation.

[0073] This embodiment is particularly suitable for heavy industrial scenarios with high requirements for active component concentration and penetration cleaning ability, such as the removal of carbon and grease deposits in automobile engine blocks and accessories, hydraulic system components and gearbox parts, precision degreasing of aluminum alloy and titanium alloy structural parts before painting, thorough cleaning of stamped parts and large castings with multiple layers of oil film, and efficient degreasing treatment of precision bearings and seals.

[0074] Example 3

[0075] This embodiment provides a 1,3-dichlorobenzene metal degreasing cleaning agent, which enhances the wetting and penetration performance of the system by increasing the amount of propylene carbonate as the main functional solvent, while using a moderately low amount of nanocomposite intermediate and imidazoline and a low loading of 1,3-dichlorobenzene. The preparation steps are as follows.

[0076] Preparation of diethylenetriamine imidazoline oleate: C1. Add 105 parts by weight of oleic acid and 37.2 parts by weight of diethylenetriamine to a reaction vessel, ensuring that the actual amount of each component meets the molar ratio of oleic acid to diethylenetriamine of 1.03:1.00; C2. Heat to 145°C under a nitrogen atmosphere and react at this temperature for 1.8 h; C3. Continue to heat to 188°C and react at an absolute pressure of 0.025 MPa for 5 h; C4. Stop the reaction when the product acid value is 8.0 mg KOH / g and the moisture content is 0.35 wt% (not higher than 0.50 wt%), cool to 55°C and discharge to obtain diethylenetriamine imidazoline oleate of this embodiment.

[0077] Preparation of 1,3-dichlorobenzene-β-cyclodextrin-coated slurry: A1. Mix 180 parts by weight of β-cyclodextrin, 1050 parts by weight of deionized water, and 480 parts by weight of ethanol (96 vol%), and stir at 40°C and 420 r / min for 38 min; A2. Add 35 parts by weight of 1,3-dichlorobenzene dropwise to the system obtained in step A1 at 40°C over 45 min, and disperse under high shear at 2500 r / min in air for 55 min; A3. Continue stirring the system at 40°C and 420 r / min for 105 min. After the system stands for 30 min, no independent oil phase precipitates, thus obtaining the 1,3-dichlorobenzene-β-cyclodextrin-coated slurry of this embodiment.

[0078] Preparation of 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate: B1. Add 18 parts by weight of tetraethyl silicate and 9 parts by weight of 3-aminopropyltriethoxysilane to the 1,3-dichlorobenzene-β-cyclodextrin encapsulation slurry of this example; B2. Add ammonia water with a mass fraction of 22 wt% by weight dropwise while stirring until the pH of the system stabilizes at 8.8, and carry out a condensation reaction at 44℃ and 420 r / min for 2.5 h; B3. After aging at 44℃ for another 10 h, filter the solid using a filter material with a pore size of 0.2 μm; wash the obtained solid three times each with ethanol and deionized water, with each washing liquid volume being 8 times the mass of the obtained solid; then, heat the solid at 38℃ and an absolute pressure of 0. The 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate of this embodiment was obtained in powder form after vacuum drying at 0.010 MPa for 10 h. B4. The median particle size D50 of the nanocomposite intermediate of this embodiment was determined by dynamic light scattering (the sample was diluted with deionized water to a solid content of 0.05 wt% before measurement, and the measurement temperature was 25 °C), and the result was 155 nm. The loading of 1,3-dichlorobenzene (based on the dry weight of the nanocomposite intermediate) was determined by solvent extraction-gas chromatography and was 23.0 wt%. Thermogravimetric analysis was used to assist in the confirmation. Under nitrogen atmosphere and a heating rate of 10 °C / min, the mass loss in the 200-250 °C range was consistent with the result of gas chromatography.

[0079] Preparation of a 1,3-dichlorobenzene metal degreasing cleaning agent: S1. Provide the nanocomposite intermediate prepared in step B3 of this embodiment; S2. Provide the diethylenetriamine imidazoline oleate prepared in step C4 of this embodiment; S3. Stir 81.3 parts by weight of deionized water, 9.5 parts by weight of propylene carbonate, 2.8 parts by weight of sodium xylenesulfonate, 1.8 parts by weight of sodium D-gluconate and 0.9 parts by weight of sodium carbonate at 42°C for 35 min until no visible undissolved matter is found in the system, add 1.7 parts by weight of diethylenetriamine imidazoline oleate provided in step S2, and stir at 42°C and 900 r / min. Stir for 28 min; S4. Add 2.0 parts by weight of the nanocomposite intermediate provided in step S1 to the system obtained in step S3, disperse at 1800 r / min for 55 min, and disperse at 42℃; monitor the pH value of the system. The pH value in this step is 9.0, which is within the range of 8.2-9.5, and no pH adjustment is required; let stand for 20 h to obtain a pre-concentrated solution with a median particle size D50 of 175 nm (measured by dynamic light scattering method; before measurement, the sample was diluted with deionized water to a solid content of 0.05 wt%, and the measurement temperature was 25℃); mix the pre-concentrated solution of this embodiment with an appropriate amount of deionized water to obtain the 1,3-dichlorobenzene metal degreasing cleaning agent of this embodiment. After step S4, let the system stand at 22℃ for 22 h, filter through a 150 mesh and then fill. The cleaning agent of this embodiment is used in undiluted form or diluted with deionized water at a weight ratio of 1:3.

[0080] Composition and performance of the cleaning agent: The 1,3-dichlorobenzene metal degreasing cleaning agent prepared in this embodiment, based on 100 parts by weight of the total cleaning agent, contains the following components: 2.0 parts by weight of 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate; 1.7 parts by weight of diethylenetriamine imidazoline oleate; 9.5 parts by weight of propylene carbonate; 2.8 parts by weight of sodium xylenesulfonate; 1.8 parts by weight of sodium D-gluconate; 0.9 parts by weight of sodium carbonate; and 81.3 parts by weight of deionized water. The loading of the 1,3-dichlorobenzene nanocomposite intermediate in this embodiment is 23.0 wt%. Combined with its usage of 2.0 parts by weight in the formulation, the actual content of 1,3-dichlorobenzene in the cleaning agent of this embodiment is calculated to be 2.0 × 23.0% = 0.460 wt%, which is consistent with the results measured by gas chromatography. The cleaning agent in this embodiment has a pH of 9.0; the median particle size D50, measured by dynamic light scattering, is 160 nm (the sample was diluted with deionized water to a solid content of 0.05 wt% before measurement, and the measurement temperature was 25°C); the volatile organic compound content, measured according to GB38508-2020, is not higher than 300 g / L; the closed-cup flash point, measured according to GB / T21615-2008, is not lower than 65°C; 50 mL of sample was placed in a transparent stoppered glass bottle, and after being placed at 40°C for 7 days, no visible stratification was observed. The cleaning agent in this embodiment does not contain dichloromethane, trichloromethane, trichloroethylene, or tetrachloroethylene in its formulation.

[0081] This embodiment is applicable to degreasing of precision parts made of non-ferrous light metals such as aluminum alloys, magnesium alloys and zinc alloys, removal of flux and light grease from semiconductor wafer carriers and electronic circuit board fixtures, surface cleaning of optical lenses and housings of precision opto-mechanical instruments, and precision pretreatment before electroplating, anodizing and chemical plating. It is especially suitable for precision manufacturing fields where there are strict requirements for controlling the amount of active residue in the cleaning solution and where the substrate has weak corrosion resistance.

[0082] Example 4

[0083] This embodiment provides a 1,3-dichlorobenzene metal degreasing cleaning agent. A high ratio of nanocomposite intermediate to 1,3-dichlorobenzene loading is selected to fully demonstrate the inclusion stability and colloidal stability of the formulation system under high-activity 1,3-dichlorobenzene dosage. The preparation steps are as follows.

[0084] Preparation of diethylenetriamine imidazoline oleate: C1. Add 120 parts by weight of oleic acid and 41.4 parts by weight of diethylenetriamine to a reaction vessel, ensuring that the actual amount of each component meets the molar ratio of oleic acid to diethylenetriamine of 1.06:1.00; C2. Heat to 158°C under a nitrogen atmosphere and react at this temperature for 1.2 h; C3. Continue to heat to 215°C and react at an absolute pressure of 0.025 MPa for 5 h; C4. Stop the reaction when the product acid value is 4.5 mg KOH / g and the moisture content is 0.20 wt% (not higher than 0.50 wt%), cool to 62°C and discharge to obtain diethylenetriamine imidazoline oleate of this embodiment.

[0085] Preparation of 1,3-dichlorobenzene-β-cyclodextrin-coated slurry: A1. Mix 140 parts by weight of β-cyclodextrin, 850 parts by weight of deionized water, and 350 parts by weight of ethanol (99 vol%), and stir at 47°C and 620 r / min for 26 min; A2. Add 70 parts by weight of 1,3-dichlorobenzene dropwise to the system obtained in step A1 at 47°C over 20 min, and disperse under high shear at 4500 r / min in air for 55 min; A3. Continue stirring the system at 47°C and 620 r / min for 95 min. After the system stands for 30 min, no independent oil phase precipitates, thus obtaining the 1,3-dichlorobenzene-β-cyclodextrin-coated slurry of this embodiment.

[0086] Preparation of 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate: B1. Add 32 parts by weight of tetraethyl silicate and 16 parts by weight of 3-aminopropyltriethoxysilane to the 1,3-dichlorobenzene-β-cyclodextrin encapsulation slurry of this example; B2. Add ammonia water with a mass fraction of 27 wt% by weight dropwise while stirring until the pH of the system stabilizes at 10.0, and carry out a condensation reaction at 56℃ and 620 r / min for 2.5 h; B3. After aging at 56℃ for 10 h, centrifuge at a relative centrifugal force of 17000 g and a centrifugation time of 45 min, and discard the supernatant; the obtained solid is washed three times each with ethanol and then with deionized water, with the volume of the washing liquid each time being 16 times the mass of the obtained solid; subsequently The 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate of this embodiment was obtained in powder form after vacuum drying at 43℃ and an absolute pressure of 0.025MPa for 10h. B4. The median particle size D50 of the nanocomposite intermediate of this embodiment was determined by dynamic light scattering (the sample was diluted with deionized water to a solid content of 0.05wt% before the determination, and the determination temperature was 25℃), and the result was 130nm. The loading of 1,3-dichlorobenzene (based on the dry weight of the nanocomposite intermediate) was determined by solvent extraction-gas chromatography and was 34.0wt%. Thermogravimetric analysis was used to assist in the confirmation. Under nitrogen atmosphere and a heating rate of 10℃ / min, the mass loss in the 200-250℃ range was consistent with the result of gas chromatography.

[0087] Preparation of a 1,3-dichlorobenzene metal degreasing cleaning agent: S1. Provide the nanocomposite intermediate prepared in step B3 of this embodiment; S2. Provide the diethylenetriamine imidazoline oleate prepared in step C4 of this embodiment; S3. Stir 81.6 parts by weight of deionized water, 7.0 parts by weight of propylene carbonate, 3.2 parts by weight of sodium xylenesulfonate, 1.5 parts by weight of sodium D-gluconate and 0.4 parts by weight of sodium carbonate at 52°C for 35 min until no visible undissolved matter is found in the system, add 1.8 parts by weight of diethylenetriamine imidazoline oleate provided in step S2, and stir at 52°C and 1400 r / min. Stir for 20 min; S4. Add 4.5 parts by weight of the nanocomposite intermediate provided in step S1 to the system obtained in step S3, disperse at 2800 r / min for 55 min, and disperse at 52℃; monitor the pH value of the system. The pH value in this step is 8.9, which is within the range of 8.2-9.5, and no pH adjustment is required; let stand for 22 h to obtain a pre-concentrated solution with a median particle size D50 of 145 nm (measured by dynamic light scattering method; before measurement, the sample was diluted with deionized water to a solid content of 0.05 wt%, and the measurement temperature was 25℃); mix the pre-concentrated solution of this embodiment with an appropriate amount of deionized water to obtain the 1,3-dichlorobenzene metal degreasing cleaning agent of this embodiment. After step S4, let the system stand at 27℃ for 20 h, filter through 180 mesh, and then fill into bottles. The cleaning agent of this embodiment is used directly in undiluted form.

[0088] Composition and performance of the cleaning agent: The 1,3-dichlorobenzene metal degreasing cleaning agent prepared in this embodiment, based on 100 parts by weight of the total cleaning agent, contains the following components: 4.5 parts by weight of 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate; 1.8 parts by weight of diethylenetriamine imidazoline oleate; 7.0 parts by weight of propylene carbonate; 3.2 parts by weight of sodium xylenesulfonate; 1.5 parts by weight of sodium D-gluconate; 0.4 parts by weight of sodium carbonate; and 81.6 parts by weight of deionized water. The loading of the 1,3-dichlorobenzene nanocomposite intermediate in this embodiment is 34.0 wt%. Combined with its usage of 4.5 parts by weight in the formulation, the actual content of 1,3-dichlorobenzene in the cleaning agent of this embodiment is calculated to be 4.5 × 34.0% = 1.530 wt%, which is consistent with the results measured by gas chromatography. The cleaning agent in this embodiment has a pH of 8.9; the median particle size D50, measured by dynamic light scattering, is 140 nm (the sample was diluted with deionized water to a solid content of 0.05 wt% before measurement, and the measurement temperature was 25°C); the volatile organic compound content, measured according to GB38508-2020, is not higher than 300 g / L; the closed-cup flash point, measured according to GB / T21615-2008, is not lower than 65°C; 50 mL of sample was placed in a transparent stoppered glass bottle, and after being placed at 40°C for 7 days, no visible stratification was observed. The cleaning agent in this embodiment does not contain dichloromethane, trichloromethane, trichloroethylene, or tetrachloroethylene in its formulation.

[0089] This embodiment is applicable to high-intensity industrial scenarios that require high active dosage of 1,3-dichlorobenzene and must ensure the performance of the original cleaning solution, such as the thorough removal of extremely heavy oil stains in the metallurgical, mining, shipbuilding and heavy equipment fields, efficient degreasing in multiple spraying processes of engine parts and precision castings, thorough removal of high-concentration extreme pressure lubricants and cutting fluid residues on heavy military parts, large injection molding and die casting molds, and one-time deep cleaning of complex greases that have accumulated over a long period of time during industrial equipment overhaul.

[0090] Comparative Example 1: Basically the same as Example 1, except that the amount of 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate in the cleaning agent is 0.4 parts by weight, and other conditions remain unchanged.

[0091] Comparative Example 2: Basically the same as Example 1, except that the amount of 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate in the cleaning agent is 6.0 parts by weight, and other conditions remain unchanged.

[0092] Comparative Example 3: It is basically the same as Example 1, except that the amount of diethylenetriamine imidazoline oleate in the cleaning agent is 0.3 parts by weight, and other conditions remain unchanged.

[0093] Comparative Example 4: Basically the same as Example 1, except that the amount of propylene carbonate in the cleaning agent is 2.0 parts by weight, and other conditions remain unchanged.

[0094] Comparative Example 5: Basically the same as Example 1, except that the amount of sodium xylenesulfonate in the cleaning agent is 0.5 parts by weight, and other conditions remain unchanged.

[0095] Comparative Example 6: Basically the same as Example 1, except that the amount of sodium D-gluconate in the cleaning agent is 0 parts by weight, and other conditions remain unchanged.

[0096] Comparative Example 7: Basically the same as Example 1, except that the pH of the system was adjusted to 7.9 in step S4, while other conditions remained unchanged.

[0097] Comparative Example 8: Basically the same as Example 1, except that the pH of the system was adjusted to 9.8 in step S4, while other conditions remained unchanged.

[0098] Comparative Example 9: It is basically the same as Example 1, except that the dispersion speed in step S4 is 800 r / min, and other conditions remain unchanged.

[0099] Performance testing:

[0100] Each sample was prepared into a diluent with a solid content of 0.01–0.10 wt% according to a uniform dilution rule. The particle size distribution was inferred by using dynamic light scattering technology through the autocorrelation function of scattering intensity. The test was carried out at 25℃ with a fixed scattering angle and refractive index model. D10, D50, D90 and polydispersity index (PDI) were measured. The mean ± standard deviation was output and superimposed with the particle size distribution curve to compare the particle size characteristics and distribution stability of each sample.

[0101] Take 50 mL of each cleaning agent sample and seal it in a transparent bottle. Store it in a constant temperature environment of 40℃ for 7 days. Observe and record the stratification and sedimentation every 24 hours. Take samples on day 0 and day 7 to measure D50. If the particles aggregate or hydrolyze, it will cause particle size drift or even phase separation. Calculate the change range of ΔD50% and the stratification height to evaluate the stability of the colloid under accelerated aging conditions.

[0102] The nanocomposite intermediate powder was weighed on a dry basis and solvent extracted. The peak area of ​​the target compound was quantified by gas chromatography. The loading of 1,3-dichlorobenzene was obtained by using an external standard curve of no less than 5 points and corrected for recovery rate. The actual content of the cleaning agent sample was determined by direct injection and comparison before and after extraction. The proportion of free state was estimated by the difference between the two. The results were reported as wt%, which comprehensively characterized the content and occurrence form of the target active component.

[0103] After derusting and degreasing, carbon steel standard test pieces of known area are accurately weighed, coated with a quantitative standard lubricating oil film, and weighed again. Then, the test pieces are immersed in the undiluted cleaning agent at 40±2℃ for 5 minutes, with consistent light spraying and stirring. After drying, they are weighed again. The quality of the oil film and the residual quality directly reflect the degreasing efficiency. Based on this, the degreasing rate (%) and residual oil content (mg / m²) are calculated.

[0104] Carbon steel test pieces were subjected to specified surface treatment and weighed, then immersed in a 25°C cleaning agent solution for 24 hours, maintaining a fixed ratio of solution volume to test piece area and consistent dissolved oxygen conditions. After removal, corrosion products were removed and the test pieces were weighed again. The mass loss was converted into corrosion rate (mm / a) using the weight loss method.

[0105] For each cleaning agent concentrate, VOC content, closed-cup flash point, and pH were measured under the same batch conditions at 23±2℃. VOC was converted to g / L to characterize the level of volatile organic compounds, closed-cup flash point was determined using the closed-cup cup method to characterize flammability risk, and pH was determined using the potentiometric method to reflect the suitable environment for corrosion inhibition and shell durability. The mean ± standard deviation of each indicator was output for n=3, and the results were analyzed in conjunction with stability and degreasing rate data to comprehensively evaluate the product's compliance safety and actual use window.

[0106] Figure 1 The particle size stability time curves of the 1,3-dichlorobenzene metal degreasing cleaning agents prepared in Examples 1 to 4 and Comparative Examples 2, 5, and 9 under accelerated aging conditions at 40°C are shown. The storage time is plotted on the horizontal axis, and the relative change in median particle size D50 ΔD50% is plotted on the vertical axis. Samples were taken approximately every 24 hours and measured using dynamic light scattering. A horizontal dashed line marks the 10% stability warning threshold. The effects of the dosage of propylene carbonate and sodium xylenesulfonate, as well as the dispersion speed, on the long-term stability of the colloid were investigated. In Examples 1 to 4, ΔD50% was below 7% during the 7-day storage period. In Comparative Examples 2, 5, and 9, ΔD50% exceeded the warning threshold. This demonstrates that propylene carbonate and sodium xylenesulfonate synergistically maintain the long-term stability of the aqueous colloid within the specified dosage range. Insufficient dispersion speed leads to incomplete deagglomeration of nanoparticles and accelerated aging and aggregation.

[0107] Figure 2The pH-colloidal stability-carbon steel corrosion rate coupling curves of the 1,3-dichlorobenzene metal degreasing cleaning agents prepared in Examples 1 to 4 and Comparative Examples 7 and 8 are shown. The horizontal axis is pH, the left vertical axis is ΔD50% after 7 days of storage at 40°C, and the right vertical axis is the carbon steel corrosion rate determined by the weight loss method. Continuous fitting curves and observation scatter points are plotted simultaneously, and the functional window of pH 8.2 to 9.5 is marked with a green dashed line. Using the pH of the system in step S4 as a variable, the dual effects of pH deviation from the window on colloidal stability and metal corrosion resistance are investigated. The results show that ΔD50% is at its lowest point within the window, and the corrosion rate is within compliance. When the pH is too low, the colloidal stability deteriorates. When the pH is too high, the hydrolysis of Si-O-Si bonds in the siloxane shell intensifies, and D50 drift is significant. This proves that pH 8.2 to 9.5 is the necessary pH range to simultaneously meet the requirements of colloidal structure durability, maintenance of imidazoline corrosion inhibitory active morphology, and hydrolysis resistance of the siloxane shell.

[0108] Figure 3 Field emission scanning electron microscope (FESEM) images of the 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate powder prepared in Example 1 show that the nanoparticles are uniformly distributed in the field of view as a loose aggregate network, without macroscopic cracks, phase segregation or large-scale pore defects; proving that a nanocomposite intermediate with uniform particle size, regular morphology and good dispersibility is obtained after low-temperature vacuum drying.

[0109] Figure 4 Macroscopic optical photographs of the 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate powder and the 1,3-dichlorobenzene metal degreasing cleaning agent prepared in Example 1 are shown. The nanocomposite intermediate is a fluffy, off-white powder. Due to the particle size falling within the Mie scattering dominance range, it forms uniform diffuse reflection of visible light across the entire wavelength range, without any agglomeration or macroscopic clumps. The liquid containing the 1,3-dichlorobenzene metal degreasing cleaning agent is a uniform milky white turbid state due to the strong scattering effect of the dispersed phase nanoparticles. After being placed at 40°C for 7 days, no visible layering was observed. This proves that the sol-gel co-condensation process involving β-cyclodextrin can stably encapsulate 1,3-dichlorobenzene in a siloxane nanoparticle system under mild conditions. The resulting cleaning agent has excellent macroscopic colloidal stability and appearance consistency.

[0110] Table 1 Performance Comparison Summary Table

[0111] Sample number Oil removal rate / % <![CDATA[Residual oil content / (mg·m -2 )]]> ΔD50(40℃, 7d) / % <![CDATA[Carbon steel corrosion rate / (mm·a -1 )]]> <![CDATA[VOC / (g·L -1 )]]> Closed-cup flash point / ℃ Example 1 94.5±0.6 28±3 4.0±0.8 0.018±0.002 265±8 70±1 Example 2 96.8±0.5 18±2 5.5±1.0 0.020±0.002 285±10 68±1 Example 3 92.0±0.8 38±4 3.5±0.7 0.015±0.002 250±7 75±1 Example 4 97.5±0.4 14±2 6.0±1.2 0.022±0.003 295±12 67±1 Comparative Example 1 84.0±1.2 95±8 2.8±0.6 0.018±0.002 200±6 78±1 Comparative Example 2 91.0±0.9 45±5 15.0±2.1 0.019±0.002 310±15 66±1 Comparative Example 3 93.8±0.7 30±3 4.7±0.9 0.060±0.005 265±8 70±1 Comparative Example 4 88.5±1.0 70±6 4.2±0.9 0.018±0.002 240±7 72±1 Comparative Example 5 86.0±1.1 80±7 12.0±2.5 0.020±0.002 260±9 70±1 Comparative Example 6 89.0±1.0 60±5 9.0±1.8 0.028±0.003 265±8 69±1 Comparative Example 7 92.5±0.8 40±4 7.5±1.5 0.045±0.004 268±9 70±1 Comparative Example 8 93.0±0.8 35±4 14.0±2.2 0.012±0.002 320±15 65±1 Comparative Example 9 90.0±0.9 55±5 18.0±3.0 0.020±0.002 270±9 70±1

[0112] As can be seen from the performance of the examples and comparative examples in Table 1, Examples 1-4 are generally superior in terms of degreasing rate and residual oil content, indicating that the effective dosage of the nanocomposite intermediate and the wetting and penetration of propylene carbonate jointly determine the degreasing efficiency. When the dosage of the intermediate is too low (Comparative Example 1), the insufficient supply of activity leads to a significant decrease in the degreasing rate, while the dosage is too high (Comparative Example 2), although it has potential activity, the stability and overall performance deteriorate due to the increased particle size drift. The pH deviation from the working window (Comparative Examples 7 and 8) will simultaneously amplify ΔD50 and change the corrosion rate, reflecting the coupling between alkaline buffer and shell durability. The insufficient corrosion inhibitor (Comparative Example 3) causes the most significant increase in corrosion rate, indicating that it is a key constraint factor for safe use.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that any equivalent structural transformations made under the concept of the present invention and using the contents of the specification and drawings of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A degreasing cleaning agent containing 1,3-dichlorobenzene metal, characterized in that, Based on 100 parts by weight of the total weight of the cleaning agent, the cleaning agent comprises the following components: 0.6-5.0 parts by weight of 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate; 0.6-4.0 parts by weight of diethylenetriamine imidazoline oleate; 3.0-12.0 parts by weight of propylene carbonate; Sodium xylenesulfonate 1.0-6.0 parts by weight; Sodium D-gluconate 0.5-4.0 parts by weight; Sodium carbonate 0.1-1.2 parts by weight; Add the remaining deionized water to a total of 100 parts by weight. The 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate is prepared from 1,3-dichlorobenzene, β-cyclodextrin, tetraethyl silicate, and 3-aminopropyltriethoxysilane. The 1,3-dichlorobenzene loading in the nanocomposite intermediate is 18.0-35.0 wt% based on the dry weight of the nanocomposite intermediate, as determined by solvent extraction-gas chromatography. The median particle size D50 is 80-180 nm, as determined by dynamic light scattering. The actual 1,3-dichlorobenzene content in the cleaning agent is 0.11-1.75 wt%, as determined by gas chromatography, and the pH value is 8.2-9.

5.

2. The 1,3-dichlorobenzene metal degreasing cleaning agent as described in claim 1, characterized in that, The 1,3-dichlorobenzene-β-cyclodextrin encapsulating slurry used in the preparation of the nanocomposite intermediate was prepared according to the following steps: A1. Mix 100-220 parts by weight of β-cyclodextrin, 600-1200 parts by weight of deionized water and 200-600 parts by weight of ethanol with a volume fraction of 95-99.9 vol%, and stir at 35-50℃ and 300-800 r / min for 20-40 min. A2. Add 20-80 parts by weight of 1,3-dichlorobenzene dropwise to the system obtained in step A1 at 35-50℃ over 10-60 min, and disperse under high shear at 2000-5000 r / min in air for 20-60 min; A3. Keep the system at 35-50℃ and 300-800r / min and continue stirring for 30-120min. When no independent oil phase is precipitated after the system has stood for 30min, 1,3-dichlorobenzene-β-cyclodextrin-encapsulated slurry is obtained.

3. The 1,3-dichlorobenzene metal degreasing cleaning agent as described in claim 2, characterized in that, The nanocomposite intermediate was prepared according to the following steps: B1. Add 10-40 parts by weight of tetraethyl silicate and 5-20 parts by weight of 3-aminopropyltriethoxysilane to the 1,3-dichlorobenzene-β-cyclodextrin coating slurry. B2. Add ammonia water with a mass fraction of 20-30 wt% by drop while stirring until the pH of the system stabilizes at 8.5-10.

5. Carry out the condensation reaction for 1-3 hours at 40-60℃ and 300-800 r / min. B3. After aging at 40-60℃ for 4-12 hours, the product is separated by centrifugation or filtration. The centrifugation force is 5000-20000g and the centrifugation time is 5-60 minutes. Alternatively, the filter material used for filtration has a pore size of 0.1-1.0 μm. The resulting solid is washed 1-3 times with ethanol and then with deionized water, with each wash volume being 5-20 times the mass of the solid. Subsequently, it is vacuum dried at 35-45℃ and an absolute pressure of 0.005-0.030 MPa for 4-12 hours to obtain a powdered 1,3-dichlorobenzene-β-cyclodextrin-siloxane nanocomposite intermediate. B4. The median particle size D50 of the obtained nanocomposite intermediate was 80-180 nm, which was determined by dynamic light scattering method; and the 1,3-dichlorobenzene loading was 18.0-35.0 wt% based on the dry basis of the nanocomposite intermediate, which was determined by solvent extraction-gas chromatography.

4. The 1,3-dichlorobenzene metal degreasing cleaning agent as described in claim 1, characterized in that, The diethylenetriamine imidazoline oleate is prepared according to the following steps: C1. Add 100-130 parts by weight of oleic acid and 33.2-47.5 parts by weight of diethylenetriamine to a reaction vessel, and ensure that the actual amount of each component meets the requirement that the molar ratio of oleic acid to diethylenetriamine is 1.00-1.10:1.00; C2. Heat to 140-160℃ under a nitrogen atmosphere and react for 1-2 hours; C3. Continue heating to 180-220℃ and react for 2-6 hours at an absolute pressure of 0.010-0.030 MPa; C4. When the product acid value is 3-10 mg KOH / g and the moisture content is not higher than 0.50 wt%, stop the reaction, cool to 50-70℃ and discharge to obtain diethylenetriamine imidazoline oleate.

5. The 1,3-dichlorobenzene metal degreasing cleaning agent as described in claim 1, characterized in that, The cleaning agent, as determined by the method specified in GB38508-2020, has a volatile organic compound content of no more than 300 g / L, a closed-cup flash point of no less than 65℃ as determined by GB / T21615-2008, a median particle size D50 of 100-180 nm, measured by dynamic light scattering method, and shows no visible stratification after being placed at 40℃ for 7 days. Furthermore, the cleaning agent does not contain dichloromethane, trichloromethane, trichloroethylene, or tetrachloroethylene in its formulation.

6. A method for preparing a 1,3-dichlorobenzene metal degreasing cleaning agent as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Provides nanocomposite intermediates; S2. Provides diethylenetriamine imidazoline oleate; S3. Stir 40-70 parts by weight of deionized water, 5-15 parts by weight of propylene carbonate, 2-8 parts by weight of sodium xylenesulfonate, 1-5 parts by weight of sodium D-gluconate and 0.2-1.5 parts by weight of sodium carbonate at 40-55℃ for 20-40 min until no undissolved matter is visible to the naked eye; add 1-6 parts by weight of diethylenetriamine imidazoline oleate provided in step S2, and stir at 40-55℃ and 800-1500 r / min for 15-30 min. S4. Add 5-25 parts by weight of the nanocomposite intermediate provided in step S1 to the system obtained in step S3 and disperse it; when the pH of the system is lower than 8.2, add 5-15 wt% sodium carbonate aqueous solution to adjust the pH to 8.2-9.5; when the pH of the system is higher than 9.5, add 5-15 wt% citric acid aqueous solution to lower it to 8.2-9.5; let it stand and mature to obtain a pre-concentrated solution with a median particle size D50 of 100-220 nm, wherein the median particle size D50 is measured by dynamic light scattering method; mix the pre-concentrated solution with deionized water to obtain the 1,3-dichlorobenzene metal degreasing cleaning agent.

7. The preparation method according to claim 6, characterized in that, Step S4 is followed by: letting the system stand at 20-30℃ for 12-24 hours, and then filtering it through a 50-200 mesh filter before filling.

8. The preparation method according to claim 6, characterized in that, Step S4 is followed by the step of using the obtained cleaning agent in undiluted form or diluted with deionized water at a weight ratio of 1:0.5 to 1:

4.

9. The preparation method according to claim 6, characterized in that, In step S4, the dispersion speed is 1500-3000 r / min, the dispersion time is 20-60 min, and the maturation time is 12-24 h.

10. The preparation method according to claim 6, characterized in that, When dispersing the nanocomposite intermediate in step S4, the dispersion temperature is 40-55℃.

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