Multifunctional industrial cleaning agent compounding process

Abstract

The application discloses a multifunctional industrial cleaning agent compounding process method. The method comprises the following steps: S1, dispersing nanometer colloidal cerium dioxide in deionized water and low-carbon alcohol additives, and obtaining a nanometer precursor liquid A through ultrasonic treatment; S2, mixing a gemini surfactant, a temperature-sensitive nonionic surfactant and a composite organic acid, and stirring to obtain a mixed liquid B; S3, adding the mixed liquid B into the nanometer precursor liquid A at 40-50 DEG C, and forming a core-shell structure microemulsion drop through high shear emulsification; and S4, adding an inhibition synergist and a defoaming agent after cooling, and stirring and ripening to obtain a finished product. The cleaning agent prepared by the application has the core-shell structure microemulsion drop, the particle size distribution D50 is 50-100 nm, the polydispersity coefficient PDI is less than 0.15, the storage stability is good, the oil removal rate is greater than 99%, the rust removal rate is greater than 98%, the corrosion rate is low, and the cleaning agent can be widely applied to one-step cleaning of complex metal components in the fields of aerospace, shipbuilding, precision machining and the like.

Description

Technical Field

[0001] This invention relates to the fields of fine chemicals and metal surface treatment technology, specifically to a multifunctional industrial cleaning agent compounding process, which is particularly suitable for one-step cleaning of complex metal components where heavy oil stains and thick rust layers coexist. Background Technology

[0002] In the fields of machinery manufacturing, automobile repair, and ship maintenance, the surfaces of industrial parts are often simultaneously contaminated with mineral grease, oxidized rust, and dust particles. Traditional cleaning processes typically employ a step-by-step approach of "degreasing first, then removing rust," meaning that an alkaline degreaser is first used to remove oil, followed by an acid pickling solution to remove rust. This step-by-step process suffers from problems such as a long process chain, high energy consumption, large wastewater discharge, and high skill requirements for operators.

[0003] While some multi-functional cleaning agents have emerged in the existing technology, they suffer from the following technical drawbacks: 1. Functional antagonism effect: The alkaline / surfactant environment required for degreasing and the acidic environment required for rust removal are thermodynamically incompatible. Simple mixing leads to system instability or decreased efficiency. Existing technologies barely maintain system stability by adding large amounts of co-solvents, but at the expense of cleaning efficiency.

[0004] 2. Mass transfer barrier: The surface of the rust layer is usually covered with an oil film. The hydrophobicity of the oil film hinders the contact between acidic rust-removing components and the rust layer. Conversely, the rough structure of the rust layer "locks in" the oil, making it difficult for surfactants to fully contact the oil droplets. This composite structure of "oil-encased rust and rust-encased oil" forms a mass transfer barrier.

[0005] 3. Interfacial competitive adsorption: Surfactants compete for adsorption at oil-water and solid-liquid interfaces. When surfactants preferentially adsorb onto oil, the corroded surface cannot be adequately wetted; conversely, the opposite is also true. Existing technologies cannot solve this interfacial competition problem.

[0006] 4. Risk of secondary pollution: Fe³ dissolved during the rust removal process + Metal ions can react with surfactants to form insoluble substances, which precipitate on the metal surface and cause secondary pollution. Furthermore, these metal ions can catalyze corrosion reactions.

[0007] Therefore, developing a multifunctional cleaning agent compounding process that can simultaneously and efficiently remove oil stains and rust while avoiding the aforementioned defects has significant industrial application value. Summary of the Invention

[0008] This invention aims to solve the technical problems in the prior art where cleaning agents cannot simultaneously and efficiently remove oil stains and rust, have poor system stability, and are prone to causing secondary pollution, and provides a multifunctional industrial cleaning agent compounding process method.

[0009] This invention optimizes the composition and process to ensure that the cleaning agent remains in a stable and uniform microemulsion state during storage, and can quickly wet oil and rust surfaces during use, thus exerting a synergistic cleaning effect.

[0010] The cleaning agent of the present invention is prepared by the compounding process of the following components in parts by weight: Deionized water: 50-70 parts; Nanocolloidal cerium dioxide: 1-5 parts (based on pure nanoparticles); Low-carbon alcohol additives: 3-8 parts; Gemini surfactant: 5-10 parts; Temperature-sensitive nonionic surfactant: 8-15 parts; Complex organic acids: 15-25 parts; Corrosion inhibitor and synergist: 2-5 parts; Defoamer: 0.1-0.5 parts; The mechanisms of action of each component are as follows: Nanocolloidal cerium dioxide: as the physical core of the core-shell structure, its surface defects (oxygen vacancies) provide active adsorption sites; at the same time, it acts as a Pickering emulsifier to stabilize microemulsions; it is also an excellent corrosion inhibitor that can suppress metal corrosion.

[0011] Low-carbon alcohol additives (isopropanol or ethanol): reduce interfacial tension, promote nanoparticle dispersion, regulate solvent polarity, and provide steric hindrance-assisted stabilization.

[0012] Gemini surfactants: possessing two hydrophobic chains and two hydrophilic head groups, they are firmly adsorbed onto the surface of nanoparticles via electrostatics and hydrogen bonding, forming a dense inner shell. The length of their linking groups determines the adsorption configuration and response sensitivity.

[0013] Thermosensitive nonionic surfactants (C12-18 fatty alcohol polyoxyethylene ether, EO=8-10): These surfactants combine with gemini surfactants through hydrophobic interactions to form a shell layer. Their cloud point characteristics are used to control adsorption behavior: they are in a critical dehydration state during high-temperature emulsification to promote adsorption, and the system is stabilized by rehydration after cooling.

[0014] Compound organic acids (citric acid:gluconic acid:oxalic acid = 2:1:1): Citric acid provides strong complexing ability, gluconic acid enhances resistance to hard water and promotes penetration, and oxalic acid quickly penetrates the rust layer. The ternary synergy achieves efficient rust removal while avoiding over-corrosion.

[0015] Corrosion inhibitor (ammonium molybdate and disodium EDTA 1:1): Ammonium molybdate forms a passivation film, and EDTA complexes free metal ions, synergistically enhancing rust prevention performance.

[0016] The compounding process described in this invention includes the following steps: S1: Preparation of Nano-Precursor Liquid A Nanocolloidal cerium dioxide was mixed with deionized water and low-carbon alcohol additives, and then ultrasonically treated at 20-30℃ for 10-20 min to obtain nanoprecursor liquid A in which the nanoparticles are in a monodisperse state; the ultrasonic frequency was 35-45kHz and the power density was 0.3-0.5W / mL.

[0017] S2: Preparation of Mixture B Gemini surfactant, thermosensitive nonionic surfactant and composite organic acid are mixed and stirred at 30-35℃ for 15-25 min to allow surfactant molecules to self-assemble into premicelles in the organic acid medium, thus obtaining mixture B.

[0018] S3: Microemulsion Phase Transition and Assembly Under constant temperature conditions of 40-50℃, the mixture B is slowly added to the nano precursor liquid A in a thin stream, while a high-shear emulsifier is started and the linear velocity is controlled at 15-25m / s for emulsification for 30-45min. During this process, surfactant molecules assemble at the interface using nanoparticles as templates to form microemulsion droplets with a core-shell structure.

[0019] S4: Post-processing The system is cooled to below 25℃ at a rate of 0.5-1.0℃ / min, corrosion inhibitors and defoamers are added, the mixture is stirred at low speed for 8-15 min, and allowed to stand for 1-3 h to mature, thus obtaining a multifunctional cleaning agent with an adaptive microemulsion phase.

[0020] Compared with the prior art, the present invention has the following beneficial effects: Simultaneous and efficient degreasing and rust removal 1. The cleaning agent prepared by this invention can simultaneously remove oil and rust. A 5% working solution, when soaked at 25°C for 10 minutes, achieves a removal rate of over 99% for HS-20 drawing oil; when soaked at 35°C for 15 minutes, it achieves a removal rate of over 98% for rust layers approximately 50 μm thick. Compared with traditional step-by-step processes, the processing time is reduced by over 50%, and energy consumption is reduced by over 30%.

[0021] 2. Excellent system stability The cleaning agent prepared by this invention has excellent storage stability: it remains clear and transparent with a particle size change of less than 10% after 30 days of storage in a temperature range of -5℃ to 50℃, and there is no stratification or sedimentation; it does not stratify after centrifugation at 3000rpm for 30min; it can adapt to 1000ppm hard water, and its resistance to hard water is significantly better than that of commercially available products.

[0022] 3. Excellent corrosion and rust prevention properties The cleaning agent of this invention has extremely low corrosivity to metal substrates: the corrosion rate on cast iron is only 0.11 g / m³. 2·h, for 45# steel 0.08g / m 2 ·h, for copper <0.05g / m 2 ·h, for aluminum alloys <0.05g / m 2 •h; After cleaning, the rust prevention time of cast iron can reach more than 72 hours, which is far superior to commercially available products (24-48 hours).

[0023] 4. Environmentally friendly and energy-saving The process of this invention can efficiently complete cleaning at room temperature to 50°C without high-temperature heating, resulting in low energy consumption. No acid mist is generated during the cleaning process, and the waste liquid has good biodegradability, meeting green and environmental protection requirements. The one-step method replaces the traditional multi-step process, reducing wastewater discharge by more than 40%.

[0024] 5. Wide applicability The cleaning agent of this invention is suitable for simultaneous cleaning of ferrous metals (cast iron, steel) and non-ferrous metals (copper, aluminum). It has excellent effects on heavy oil stains and thick rust layers, and can be widely used in aerospace, shipbuilding, automobile repair, precision machining and other fields. Attached Figure Description

[0025] Figure 1 This is a flowchart of the multifunctional industrial cleaning agent compounding process of the present invention; Figure 2 This is a detailed flow chart of the compounding process of the present invention. Detailed Implementation

[0026] The following is in conjunction with the appendix Figure 1-2 The technical solution of the present invention will be described in detail below with reference to specific embodiments. It should be emphasized that the embodiments described herein are only used to illustrate the working principle of the present invention and do not constitute any limitation on the scope of protection.

[0027] Example 1 (Baseline Formulation) The cleaning agent is prepared according to the following components and proportions:

[0028] Preparation process: S1: Mix 3.5 parts of nano-colloidal cerium dioxide, 6.0 parts of isopropanol and 20 parts of deionized water, and sonicate at 25°C (40 kHz, power density 0.4 W / mL) for 15 min to obtain nano-precursor solution A.

[0029] S2: Mix 7.0 parts of Gemini surfactant, 11.0 parts of C12EO9 and a complex organic acid (9.0 parts of citric acid + 6.0 parts of gluconic acid solution + 4.5 parts of oxalic acid), and stir at 32°C for 20 min to obtain mixture B.

[0030] S3: Add mixture B slowly into nano-precursor liquid A in a thin stream and emulsify at 43°C with high shear (linear velocity 20 m / s) for 35 min.

[0031] S4: Cool to 23°C at a rate of 0.8°C / min, add 1.5 parts ammonium molybdate, 1.5 parts disodium EDTA and 0.2 parts defoamer, stir at low speed (100 rpm) for 10 min, and let stand to mature for 2 h.

[0032] Product performance: Appearance: Pale yellow transparent liquid; pH value (1% aqueous solution): 8.2; Viscosity (25℃): 28 mPa·s; Particle size D50: 68 nm, PDI: 0.12; Surface tension (0.1%): 31.5 mN / m; Oil removal rate (5%, 25℃, 10min): 99.5%; Rust removal rate (5%, 35℃, 15min): 98.2%; Corrosion rate (cast iron): 0.11 g / m 2 ·h; Centrifugation stability: No stratification at 3000 rpm for 30 min; Hard water resistance (1000ppm): Clear and transparent; Example 2 (Nanoparticle Size Optimization) Except for the nanoparticle size, the formulation and process were the same as in Example 1. Samples with particle sizes of 10 nm, 15 nm, 25 nm, 35 nm, 50 nm, and 80 nm were prepared, and the test results are shown in the table below:

[0033] Example 3 (Optimization of the length of the linking group in a gemini surfactant) With the hydrophobic chain length m=12 fixed, the length s of the linking group was changed, and the rest was the same as in Example 1. Results:

[0034] Example 4 (Optimization of EO number of temperature-sensitive surfactant) The alkyl chain was kept constant at C12, the EO number was changed, and the rest was the same as in Example 1. Results:

[0035] Example 5 (Optimization of Organic Acid Ratio) The total amount of organic acids was fixed at 18 parts, and the ratio of citric acid:gluconic acid:oxalic acid was varied, while the rest remained the same as in Example 1. Results:

[0036] Example 6 (Emulsification Linear Speed ​​Optimization) With other conditions kept constant, the emulsification linear velocity was changed. Results:

[0037] Example 7 (Emulsification Temperature Optimization) With other conditions kept constant, the emulsification temperature was changed, and the results were as follows:

[0038] Example 8 (Optimization of Cooling Rate) With other conditions kept constant, the cooling rate was changed. Results:

[0039] Comparative Example 1 (without nanoparticles) The nano-colloidal cerium dioxide was removed from the formulation and replaced with an equal volume of deionized water; the rest remained the same as in Example 1. Results: After 7 days, stratification occurred, the rust removal rate decreased to 75.8%, and the corrosion rate increased to 0.45 g / m³. 2 •h, poor resistance to hard water (500ppm is enough to cause turbidity).

[0040] Comparative Example 2 (without Gemini surfactant) The gemini surfactant was replaced with an equal amount of single-chain surfactant (dodecyltrimethylammonium bromide), and the rest was the same as in Example 1. Results: Particle size 156 nm, PDI 0.35, degreasing rate 92.5%, rust removal rate 85.6%, no adaptive characteristics.

[0041] Comparative Example 3 (without temperature-sensitive surfactant) An equal amount of non-temperature-sensitive surfactant (C12EO9, but mixed at room temperature without high-temperature emulsification) was used instead, with the rest the same as in Example 1. Results: Particle size 320 nm, PDI 0.58, stratification after 24 h, oil removal rate 88.5%, rust removal rate 82.3%.

[0042] Comparative Example 4 (Simple Mixing Process) The formula was the same as in Example 1, but all materials were added at once and stirred at room temperature for 2 hours. Results: Immediate stratification, particle size 485 nm, PDI 0.65, degreasing rate 82.5%, and rust removal rate 75.8%.

[0043] Comparison Example 5 (Comparison of Commercially Available Products) Two commercially available multi-purpose cleaning agents were selected and tested under the same conditions. The results are summarized below:

Claims

1. A compounding process for a multifunctional industrial cleaning agent, characterized in that, Includes the following steps: S1: Disperse colloidal cerium dioxide nanoparticles with a particle size of 10-50 nm in a mixture of deionized water and low-carbon alcohol additives, and treat with ultrasound for 10-20 min to prepare nano-precursor liquid A in which the nanoparticles are in a monodisperse state. S2: Mix the gemini surfactant, the thermosensitive nonionic surfactant and the composite organic acid, and stir at 30-35℃ for 15-25 min to allow the surfactant molecules to self-assemble into premicelles in the organic acid medium, thus obtaining mixture B; S3: Under constant temperature conditions of 40-50℃, add mixture B to nano precursor liquid A, and simultaneously start high shear emulsification, control the linear velocity to 15-25m / s, emulsify for 30-45min, so that surfactant molecules can assemble at the interface with nanoparticles as templates to form microemulsion droplets with core-shell structure. S4: Cool the system to below 25℃ at a rate of 0.5-1.0℃ / min, add corrosion inhibitor and defoamer, stir at low speed for 8-15min, and let stand for 1-3h to obtain a multifunctional cleaning agent with adaptive microemulsion.

2. The compounding process according to claim 1, characterized in that, The nanocolloidal cerium dioxide has a particle size of 20-30 nm, a crystal structure of fluorite type, a surface oxygen vacancy defect concentration not less than 10 19 cm -3 , and a surface hydroxyl density not less than 5 per nm 2 .

3. The compounding process according to claim 1, characterized in that, The low-carbon alcohol additive is isopropanol or ethanol, and its dosage is 10-15% of the amount of deionized water.

4. The compounding process according to claim 1, characterized in that, The gemini surfactant has a general formula: [C m H 2m+1 -N + (CH3)2-(CH2) s -N + (CH3)2-C m H 2m+1 ]·2Br - Where m=12-16, s=6-8; the thermosensitive nonionic surfactant is C12-C18 fatty alcohol polyoxyethylene ether, with an ethylene oxide addition number of 8-10 and a cloud point of 55-70℃.

5. The compounding process according to claim 1, characterized in that, The compound organic acid is composed of citric acid, gluconic acid and oxalic acid in a mass ratio of 2:1:1, and the total amount of the three accounts for more than 95% of the total organic acid.

6. The compounding process according to claim 1, characterized in that, The amounts of each raw material, by weight, are as follows: 50-70 parts deionized water, 1-5 parts nano-colloidal cerium dioxide, 3-8 parts low-carbon alcohol additive, 5-10 parts gemini surfactant, 8-15 parts thermosensitive nonionic surfactant, 15-25 parts compound organic acid, 2-5 parts corrosion inhibitor, and 0.1-0.5 parts defoamer.

7. The compounding process according to claim 1, characterized in that, In step S3, the linear velocity of high-shear emulsification is 18-22 m / s, the emulsification time is 30-40 min, the temperature is 42-45℃, and the temperature control accuracy is ±1℃.

8. The compounding process according to claim 1, characterized in that, The corrosion inhibitor is a compound composed of ammonium molybdate and disodium EDTA in a mass ratio of 1:

1.

9. A multifunctional industrial cleaning agent, characterized in that, It is prepared by the compounding process described in any one of claims 1-8.

10. The multifunctional industrial cleaning agent according to claim 9, characterized in that, Its microstructure is a core-shell microemulsion droplet with nano-cerium dioxide as the core and surfactant as the shell. The particle size distribution D50 is 50-100nm, the polydispersity index PDI is <0.15, and the particle size change rate is <10% after 30 days of storage in the temperature range of -5℃ to 50℃.

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