Low-foaming high detergency water-based cleaning agent for automobiles and preparation method thereof

Abstract

The application discloses a low-foam high-detergency water-based cleaning agent for automobiles and a preparation method thereof. The cleaning agent is composed of the following components in parts by weight: 5-20 parts of hexadecyl trimethyl ammonium salicylate, 1-8 parts of a low-foam non-ionic wetting agent, 0.5-5 parts of a chelating agent, 2-10 parts of an environmentally-friendly solvent, 0.1-2 parts of an inhibitor and the balance of deionized water. The low-foam non-ionic wetting agent is an ethylene oxide / propylene oxide block copolyether with a cloud point range of 25-40 DEG C. The preparation method comprises the following steps: dissolving hexadecyl trimethyl ammonium salicylate in deionized water, adding the low-foam non-ionic wetting agent, the chelating agent, the environmentally-friendly solvent and the inhibitor in sequence, stirring until complete dissolution, and adding water to obtain the cleaning agent. The application realizes intrinsic low foaming and high detergency performance without adding a defoaming agent through the synergistic compounding of an ionic liquid and the low-foam non-ionic wetting agent, and the preparation process is simple and suitable for the cleaning scene of automobile automatic car washers and manual water gun cleaning.

Description

Technical Field

[0001] This invention belongs to the field of automotive cleaning agent technology, specifically relating to a low-foaming, high-detergent water-based automotive cleaning agent and its preparation method. Background Technology

[0002] During driving, the surface of a car body and its parts easily accumulates various complex contaminants such as engine oil, asphalt, wax, and dust, requiring regular cleaning. Water-based cleaning agents have become the mainstream choice due to their environmental friendliness and low cost. However, traditional water-based cleaning agents have long faced a technical dilemma: achieving both high detergency and low foaming performance. On the one hand, efficient detergency usually relies on highly active surfactants, but their strong foaming properties lead to excessive foam during cleaning, which not only reduces cleaning efficiency and increases rinsing water consumption but also easily causes bubble blockage in automatic car wash equipment. On the other hand, existing low-foaming cleaning agents often use defoamers such as organosilicone oil and polyether-modified silicone oil to suppress foaming. However, the introduction of defoamers reduces detergency and is prone to precipitation and failure under low temperature or high hardness water conditions. The residue may also affect subsequent painting processes.

[0003] To address the aforementioned issues, researchers have attempted to achieve foam-free, high-detergency cleaning using covalently modified cationic surfactants, but these surfactants have fixed molecular structures and poor tunability. In recent years, ionic liquids have attracted attention due to their strong structural designability. Patent CN107827926A discloses salicylic acid-functionalized quaternary ammonium ionic liquids for use in water-based lubricants, but it does not cover their application in the cleaning field, nor does it reveal their potential for synergistic effects in low foaming and detergency. Therefore, developing a novel automotive water-based cleaning agent that requires no external defoamer and possesses both intrinsically low foaming and high detergency performance has significant industrial application value. Summary of the Invention

[0004] To address the problem that existing technologies often struggle to achieve both high detergency and low foaming, and rely on external defoamers, this invention proposes a low-foaming, high-detergency water-based automotive cleaning agent and its preparation method. Using hexadecyltrimethylammonium salicylate as the main surfactant, it achieves intrinsically low foaming and high detergency performance without the need for defoamers, making it suitable for automatic car washes and manual water gun cleaning.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A low-foaming, high-detergent water-based automotive cleaner, wherein the water-based cleaner is prepared from the following raw materials in parts by weight:

[0007] 5-20 parts of hexadecyltrimethylammonium salicylate, 1-8 parts of low-foaming nonionic wetting agent, 0.5-5 parts of chelating agent, 2-10 parts of environmentally friendly solvent, 0.1-2 parts of corrosion inhibitor, and the balance being deionized water, totaling 100 parts by weight.

[0008] Preferably, the low-foaming nonionic wetting agent is ethylene oxide / propylene oxide block copolymer ether with a cloud point range of 25-40℃.

[0009] Preferably, the chelating agent is one or more of sodium gluconate, sodium citrate, or disodium ethylenediaminetetraacetate; the environmentally friendly solvent is one or more of diethylene glycol butyl ether, dipropylene glycol methyl ether, or ethylene glycol tert-butyl ether; and the corrosion inhibitor is benzotriazole.

[0010] Preferably, the specific preparation steps of the low-foaming, high-detergne water-based automotive cleaning agent are as follows:

[0011] S1. Dissolve ammonium hexadecyltrimethylsalicylate in 30%-50% of the formula amount of deionized water and stir at 20-30℃ until completely dissolved;

[0012] S2. Add the low-foaming nonionic wetting agent, chelating agent, environmentally friendly solvent and corrosion inhibitor in sequence, and control the stirring speed to 200-500 rpm, and stir for 10-30 minutes until completely dissolved.

[0013] S3. Add deionized water to the total mass percentage and continue stirring for 5-10 minutes to obtain the water-based cleaning agent.

[0014] Preferably, the water-based cleaning agent is diluted with water to a concentration of 1%-5% by mass when used.

[0015] Preferably, the water-based cleaning agent has a pH value of 7-9 at 25°C.

[0016] Preferably, the water-based cleaning agent, under conditions of 25°C and 200ppm hard water, has an initial foam height ≤60mL and a detergency ≥90%.

[0017] Due to the adoption of the above technical solution, the beneficial effects of the present invention are: the cleaning agent of the present invention has excellent low foaming performance and high detergency performance, and does not require the addition of external defoamers; it is non-corrosive to car paint and metal parts, and has good compatibility; the preparation process is simple, and it is suitable for various scenarios such as automatic car wash machines and manual water gun cleaning. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0019] Example 1: This Example 1 describes a low-foaming, high-detergne-removing water-based automotive cleaner, prepared from the following raw materials in parts by weight:

[0020] 10 parts of hexadecyltrimethylammonium salicylate, 5 parts of low-foaming nonionic wetting agent (ethylene oxide / propylene oxide block copolymer, cloud point 33℃), 2 parts of chelating agent (sodium gluconate), 5 parts of environmentally friendly solvent (diethylene glycol butyl ether), 0.5 parts of corrosion inhibitor (benzotriazole), and the balance is deionized water.

[0021] The preparation method of hexadecyltrimethylsalicylic acid ammonium is as follows:

[0022] S1. Dissolve hexadecyltrimethylammonium bromide in deionized water, heat in a 50°C water bath, control the stirring speed at 300 rpm, and stir for 15 min until completely dissolved to obtain a hexadecyltrimethylammonium bromide solution.

[0023] S2. Add sodium salicylate to deionized water, heat in a 50°C water bath, control the stirring speed at 300 rpm, stir for 10 minutes until completely dissolved, and obtain sodium salicylate solution.

[0024] S3. In a constant temperature water bath at 50℃, the stirring speed is controlled at 350 rpm. Sodium salicylate solution is slowly added dropwise to hexadecyltrimethylammonium bromide solution. The addition time is controlled at 30 min. After the addition is completed, the reaction is stirred for 1 h to generate a white precipitate.

[0025] S4. Stop stirring, let stand and cool to room temperature, filter and separate the white precipitate using a vacuum filter, wash the precipitate 2-3 times with deionized water, and dry it in a vacuum drying oven at 60℃ for 12 hours to obtain ammonium hexadecyltrimethylsalicylate.

[0026] This embodiment describes a method for preparing a low-foaming, high-detergne water-based automotive cleaning agent. The specific preparation steps are as follows:

[0027] S1. Add the prepared ammonium hexadecyltrimethylsalicylate to 30 parts of deionized water, and stir at 250 rpm for 10 minutes at 25°C until completely dissolved.

[0028] S2. Add low-foaming nonionic wetting agent, chelating agent, environmentally friendly solvent and corrosion inhibitor in sequence, control the stirring speed to 350 rpm, and stir for 20 minutes until completely dissolved.

[0029] S3. Add deionized water to a total mass of 100 parts, control the stirring speed at 300 rpm, and continue stirring for 8 minutes to obtain the low-foaming, high-detergency automotive water-based cleaning agent.

[0030] Example 2: This Example 2 describes a low-foaming, high-detergency water-based automotive cleaner. The water-based cleaner is prepared from the following raw materials in parts by weight:

[0031] 5 parts of hexadecyltrimethylammonium salicylate, 1 part of low-foaming nonionic wetting agent (ethylene oxide / propylene oxide block copolymer, cloud point 33℃), 0.5 parts of chelating agent (sodium gluconate), 2 parts of environmentally friendly solvent (diethylene glycol butyl ether), 0.1 parts of corrosion inhibitor (benzotriazole), and the balance is deionized water;

[0032] The preparation method of ammonium hexadecyltrimethylsalicylate in Example 2 is the same as that in Example 1;

[0033] The preparation method of the low-foaming, high-detergency water-based automotive cleaning agent in Example 2 is the same as that in Example 1.

[0034] Example 3: This Example 3 describes a low-foaming, high-detergency water-based automotive cleaner. The water-based cleaner is prepared from the following raw materials in parts by weight:

[0035] 20 parts of hexadecyltrimethylammonium salicylate, 8 parts of low-foaming nonionic wetting agent (ethylene oxide / propylene oxide block copolymer, cloud point 33℃), 5 parts of chelating agent (sodium gluconate), 10 parts of environmentally friendly solvent (diethylene glycol butyl ether), 2 parts of corrosion inhibitor (benzotriazole), and the balance is deionized water.

[0036] The preparation method of ammonium hexadecyltrimethylsalicylate in Example 3 is the same as that in Example 1;

[0037] The preparation method of the low-foaming, high-detergency water-based automotive cleaning agent in Example 3 is the same as that in Example 1.

[0038] Comparative Example 1: The water-based cleaning agent of Comparative Example 1 was prepared from the following raw materials in parts by weight:

[0039] 10 parts of hexadecyltrimethylammonium salicylate, 2 parts of chelating agent (sodium gluconate), 5 parts of environmentally friendly solvent (diethylene glycol butyl ether), 0.5 parts of corrosion inhibitor (benzotriazole), and the balance is deionized water;

[0040] The preparation method of ammonium hexadecyltrimethylsalicylate in Comparative Example 1 is the same as that in Example 1;

[0041] The preparation method of the water-based cleaning agent in Comparative Example 1 is the same as that in Example 1, except that a low-foaming nonionic wetting agent is not added.

[0042] Comparative Example 2: The water-based cleaning agent of Comparative Example 2 was prepared from the following raw materials in parts by weight:

[0043] 10 parts hexadecyltrimethylammonium bromide, 5 parts low-foaming nonionic wetting agent (ethylene oxide / propylene oxide block copolymer, cloud point 33℃), 2 parts chelating agent (sodium gluconate), 5 parts environmentally friendly solvent (diethylene glycol butyl ether), 0.5 parts corrosion inhibitor (benzotriazole), and the balance is deionized water;

[0044] The preparation method of the water-based cleaning agent in Comparative Example 2 is the same as that in Example 1, except that hexadecyltrimethylammonium salicylate is replaced with hexadecyltrimethylammonium bromide that has not been functionalized with salicylic acid.

[0045] Performance testing

[0046] 1. Foam performance test

[0047] The foam performance was determined using the modified Ross-Miles method (referencing GB / T 7462-1994 standard): An appropriate amount of the cleaning agent sample was accurately weighed, and a 0.25% (w / w) test solution was prepared using 3 mmol / L calcium ion hard water. The solution was preheated to the test temperature in a constant temperature water bath at 50±0.5℃. 50 mL of the test solution was poured along the inner wall of the jacketed graduated cylinder to the 50 mL mark, ensuring no foam was generated on the surface. Then, 500 mL of the test solution was poured into a separatory funnel. The stopcock was slowly opened to allow the solution to flow vertically from a height of 450 mm above the liquid surface. The initial foam height (mL) was recorded immediately after the solution had completely flowed out. The foam height was recorded again 3 minutes and 5 minutes after the flow stopped. The same sample was measured three times, and the arithmetic mean was taken as the final result. The difference between repeated measurements should not exceed 15 mL.

[0048] Table 1. Test data of foam performance of different samples

[0049]

[0050] The initial foam heights of Examples 1-3 of this invention were 52 mL, 58 mL, and 45 mL, respectively, all ≤60 mL, and the foam height decreased to 12-18 mL after 5 minutes, exhibiting excellent low-foaming characteristics and rapid foam bursting ability. Comparative Example 1 had an initial foam height of 68 mL, and still had 30 mL after 5 minutes, with significantly higher foam levels than the Examples; Comparative Example 2 had an initial foam height as high as 185 mL, and still had 95 mL after 5 minutes, exhibiting high foaming and stable foam characteristics. The results indicate that the compound system of hexadecyltrimethylammonium salicylate and EO / PO block copolymer ether has a significant low-foaming synergistic effect, achieving intrinsic low-foaming performance without the need for external defoamers.

[0051] 2. Detergent cleaning power test

[0052] The detergency was determined using the gravimetric method (referencing JB / T 4323-2019 standard): First, a metal test piece (45# steel, 50mm×30mm×2mm) was prepared, polished with sandpaper, cleaned with anhydrous ethanol and acetone, dried with hot air, and cooled in a desiccator for later use. Artificial oil stains were prepared according to the formula (8% barium petroleum sulfonate, 3.5% lanolin magnesium soap, 2% lanolin, 30% industrial petroleum jelly, 34.5% No. 20 machine oil, 12% No. 30 machine oil, 2% calcium-based grease, and 8% alumina). The test piece was immersed in the oil stain at 80℃ for 5 minutes, drained for 20 minutes, and then weighed (accurate to 0.1). Calculate the amount of oil stains coated (controlled within 100-120 mg); fix the oil-coated sample on the oscillating washer, immerse it in 3% cleaning agent solution at 65±2℃, let it stand for 3 min, then oscillate for 3 min (oscillation frequency 30±1 times / min, oscillation distance 50±2 mm), take it out and oscillate 10 times in distilled water at 65±2℃, dry it in an oven at 70±2℃ for 30 min and weigh it; calculate the detergency (%) according to the formula = (mass before cleaning - mass after cleaning) / amount of oil stains coated × 100%, and perform three parallel measurements on the same sample, taking the arithmetic mean as the result.

[0053] Table 2. Detergent power test data for different samples

[0054]

[0055] The detergency of Examples 1-3 of this invention were 92%, 88%, and 95%, respectively, all exceeding 88%, with Example 3 achieving a detergency of up to 95%, meeting the requirements for high detergency performance. The detergency of Comparative Example 1 was 78%, a decrease of 14 percentage points compared to Example 1; the detergency of Comparative Example 2 was 72%, a decrease of 20 percentage points compared to Example 1. The results indicate that the addition of a low-foaming nonionic wetting agent significantly contributes to improving detergency, and the functional modification of salicylate is crucial for enhancing detergency performance.

[0056] 3. pH value test

[0057] pH values ​​are determined using the potentiometric method (referencing GB / T 6368-2008 standard): First, prepare a 1% (w / w) solution of the cleaning agent to be tested using carbon dioxide-free distilled water, stirring thoroughly until completely dissolved; calibrate the pH meter at 25°C using two standard buffer solutions (such as phthalate standard buffer solution and borate standard buffer solution), adjusting the temperature compensation knob to 25°C; rinse the glass electrode and reference electrode (or composite electrode) with distilled water and blot dry with filter paper, immerse them in the solution to be tested, and keep the solution homogeneous under magnetic stirring. Record the pH value after the reading stabilizes; measure the same sample twice in parallel, and the difference between the two measurements should not exceed 0.1 pH units, taking the arithmetic mean as the final result.

[0058] Table 3. pH test data for different samples

[0059]

[0060] The pH values ​​of Examples 1-3 of this invention are 8.21, 7.83, and 8.49, respectively, all within the range of 7-9 defined in claim 7 of this invention, indicating weak alkalinity, which is beneficial for the emulsification, wetting, and peeling of oil stains, while posing no risk of corrosion to automotive paint and metal parts. The pH value of Comparative Example 1 is 8.06, close to that of Example 1, indicating that the addition of the low-foaming nonionic wetting agent has little effect on the pH value of the system; the pH value of Comparative Example 2 is 7.53, slightly lower than that of Example 1, indicating that the pH value of the system slightly increases after salicylic acid functionalization, which may be related to the buffering capacity of salicylate.

[0061] 4. Stability Test

[0062] The determination of high and low temperature stability is in accordance with the JB / T 4323-2019 standard. The stoppered graduated cylinder method is used to conduct high temperature and low temperature tests respectively: For the high temperature test, 50 mL of the cleaning agent stock solution is placed in a 50 mL stoppered graduated cylinder, and after stopping, it is placed in a constant temperature water bath at (60±2)℃. The water level should be above the 30 mL mark of the stoppered graduated cylinder. After maintaining the constant temperature for 6 hours, it is taken out and cooled to room temperature to check the liquid state; For the low temperature test, the sample that has no unstable phenomenon after the high temperature test (if unstable phenomenon occurs, a new sample is taken) is placed in a low temperature freezer at (-18±3)℃ for 1 hour. After taking it out, the test solution is allowed to return to room temperature and kept for 1 hour. Then the test solution is poured 5 times and the liquid state is observed. The same sample is measured twice in parallel, and the results of the two measurements should be consistent.

[0063] Table 4. Stability test data for different samples

[0064]

[0065] Examples 1-3 of this invention, after undergoing high-temperature (60℃×6h) and low-temperature (-18℃×1h) tests, all maintained a uniform and transparent appearance, without stratification, precipitation, or exudation, demonstrating excellent high and low temperature stability. Comparative Examples 1 and 2 also passed the high and low temperature stability test, showing no abnormal changes in appearance. The results indicate that the cleaning agent of this invention exhibits excellent stability under normal storage and use conditions, meeting the shelf-life requirements of industrial products.

[0066] 5. Corrosion test

[0067] The corrosion resistance was determined according to JB / T 4323-2019 standard, using the full immersion method: First, metal test pieces were prepared, selecting three types: 45 steel (50mm×30mm×2mm), H62 brass (50mm×25mm×2mm), and LY12 hard aluminum (50mm×25mm×2mm). After polishing with sandpaper, the pieces were sequentially cleaned with solvent gasoline and anhydrous ethanol, dried with hot air, and then placed in a desiccator to cool for 30 minutes before weighing (accurate to 0.1mg). The test pieces were then suspended in a 500mL wide... Pour sufficient undiluted cleaning agent into a bottle to immerse the test piece, cover it, and place it in a constant temperature water bath at (60±2)℃ for 4 hours. Remove the test piece, rinse it with distilled water, dehydrate it with anhydrous ethanol, dry it with hot air, weigh it, observe the changes in appearance, and calculate the change in mass. The appearance is rated according to grades 0-4 (Grade 0: no visible corrosion, bright surface; Grade 1: slight discoloration or loss of gloss; Grade 2: obvious discoloration or a small amount of rust spots; Grade 3: moderate corrosion; Grade 4: severe corrosion). The same sample is measured twice in parallel, and the arithmetic mean is taken as the result.

[0068] Table 5 Corrosion test data for different samples

[0069]

[0070] The corrosion test results of the three metal samples (45# steel, H62 brass, and LY12 hard aluminum) in Examples 1-3 of this invention were all Grade 0 (bright surface, no visible corrosion), with an absolute mass change of ≤0.5mg, far below the ±2mg requirement of JB / T 4323-2019 standard. This indicates that the cleaning agent of this invention does not corrode commonly used automotive metal materials and has excellent corrosion inhibition performance. The results of Comparative Example 1 are similar to those of Example 1, indicating that the addition of a low-foaming nonionic wetting agent has no significant effect on corrosion. The appearance rating of the sample in Comparative Example 2 dropped to Grade 1 (slight discoloration or loss of gloss), indicating that salicylic acid functionalization helps improve the corrosion inhibition performance of the system.

[0071] 6. Rinsing performance test

[0072] The rinsing performance was determined according to JB / T 4323-2019 standard, using the swing-wash method: First, a No. 45 steel metal test piece (50mm×30mm×2mm) was prepared according to the standard. After being polished with sandpaper, it was cleaned sequentially with solvent gasoline and anhydrous ethanol, dried with hot air, and then placed in a desiccator to cool for later use. A 3% (w / w) test solution of the cleaning agent to be tested was prepared and heated to 65±2℃. The test piece was fixed on the swing-washer, immersed in the test solution, and left to stand for 3 minutes, followed by swing-washing for 3 minutes (swing frequency 30±1 times / min, swing distance 50±2mm). The test piece was then removed and rinsed 10 times in 500mL distilled water at 65±2℃. The surface condition of the test piece and the condition of the rinsing solution were observed. The rinsing performance was considered qualified when there were no visible residues on the surface of the test piece after rinsing and the rinsing solution was clear, transparent, and without foam. The same sample was tested twice in parallel, and the results of the two tests should be consistent.

[0073] Table 6. Test data on rinsing performance of different samples

[0074]

[0075] After rinsing, the test pieces in Examples 1-3 of this invention showed clean surfaces with no visible residue, and the rinsing solution was clear, transparent, and foam-free, demonstrating excellent rinsing performance and effectively reducing the amount of rinsing water and the number of rinsing cycles. Comparative Example 1 showed similar results to Example 1, indicating that the addition of a low-foaming nonionic wetting agent had little impact on rinsing performance. Comparative Example 2 showed a small amount of foam residue in its rinsing solution, requiring 1-2 additional rinsing cycles to achieve the same level of cleanliness. The results indicate that the low-foaming properties of this invention significantly improve the rinsing performance of the cleaning agent, meeting energy-saving and environmental protection requirements.

Claims

1. A low-foaming, high-detergent water-based automotive cleaning agent, characterized in that, The water-based cleaning agent is prepared from the following raw materials in parts by weight: 5-20 parts of hexadecyltrimethylammonium salicylate, 1-8 parts of low-foaming nonionic wetting agent, 0.5-5 parts of chelating agent, 2-10 parts of environmentally friendly solvent, 0.1-2 parts of corrosion inhibitor, and the balance being deionized water, totaling 100 parts by weight.

2. The low-foaming, high-detergent water-based automotive cleaning agent according to claim 1, characterized in that, The low-foaming nonionic wetting agent is an ethylene oxide / propylene oxide block copolymer ether with a cloud point range of 25-40℃.

3. The low-foaming, high-detergent water-based automotive cleaning agent according to claim 1, characterized in that, The chelating agent is one or more of sodium gluconate, sodium citrate, or disodium ethylenediaminetetraacetate; the environmentally friendly solvent is one or more of diethylene glycol butyl ether, dipropylene glycol methyl ether, or ethylene glycol tert-butyl ether; and the corrosion inhibitor is benzotriazole.

4. A low-foaming, high-detergent water-based automotive cleaning agent according to any one of claims 1-3, characterized in that, The specific preparation steps are as follows: S1. Dissolve ammonium hexadecyltrimethylsalicylate in 30%-50% of the formula amount of deionized water and stir at 20-30℃ until completely dissolved; S2. Add the low-foaming nonionic wetting agent, chelating agent, environmentally friendly solvent and corrosion inhibitor in sequence, and control the stirring speed to 200-500 rpm, and stir for 10-30 minutes until completely dissolved. S3. Add deionized water to the total mass percentage and continue stirring for 5-10 minutes to obtain the water-based cleaning agent.

5. A low-foaming, high-detergent water-based automotive cleaning agent according to any one of claims 1-3, characterized in that, The water-based cleaning agent is diluted with water to a concentration of 1%-5% by mass when used.

6. A low-foaming, high-detergent water-based automotive cleaning agent according to any one of claims 1-3, characterized in that, The water-based cleaning agent has a pH value of 7-9 at 25°C.

7. A low-foaming, high-detergent water-based automotive cleaning agent according to any one of claims 1-3, characterized in that, The water-based cleaning agent, when tested at 25°C and 200ppm hard water, exhibits an initial foam height ≤60mL and a detergency ≥90%.

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