Automobile cooling system hose release agent cleaning agent, preparation method and cleaning method

Abstract

The present application relates to the technical field of rubber cleaning agent, and discloses a kind of automobile cooling system rubber pipe release agent cleaning agent, preparation method and cleaning method, and the cleaning agent includes fatty acid methyl ester ethoxylate 6~12 parts, narrow distribution isomerized tridecanol polyoxyethylene ether 4~8 parts, alpha-olefin sulfonate 2~5 parts, alkyl glucoside 1~3 parts, weak base saponification aid 2~5 parts, chelating dispersant 2~4 parts, rubber protective agent 0.2~0.6 parts;When preparing, deionized water is added to the reaction kettle and heated, chelating dispersant and weak base saponification aid are added, and a premix A is obtained by dissolving;Fatty acid methyl ester ethoxylate, narrow distribution isomerized tridecanol polyoxyethylene ether, alpha-olefin sulfonate and alkyl glucoside are added after cooling, and a mixture B is obtained by stirring;Rubber protective agent is added, stirred and cooled to room temperature, and the cleaning agent is filtered.The present application can efficiently remove the residual release agent on the surface of the rubber pipe of the automobile cooling system under mild conditions, and simultaneously solve the problems of secondary deposition and substrate protection.

Description

Technical Field

[0001] This invention belongs to the field of rubber cleaning agent technology, and particularly relates to a release agent and cleaning agent for automotive cooling system hoses, its preparation method and cleaning method. Background Technology

[0002] Automotive cooling system hoses are mostly made of EPDM rubber through vulcanization. During the production process, a release agent needs to be sprayed to prevent the rubber from sticking to the mold. Currently, the mainstream release agent is a water-based composite emulsion of "fatty acid metal soap (zinc stearate / calcium) + trace amount of methyl silicone oil + polyether polyol". After vulcanization, a composite fouling layer is formed on the surface of the hose, consisting of a cured fatty acid soap film and a trace amount of hydrophobic silicone oil film.

[0003] Cleaning this complex fouling presents three major technical challenges: 1. Silicone oil migrates to the outermost layer, forming a hydrophobic barrier that hinders the penetration of water-based cleaning agents; fatty acid soaps solidify in the inner layer, forming a crystalline hard film that is difficult to remove with conventional surfactants. 2. Low-molecular-weight components that penetrate into the micropores (0.1~5μm) of the EPDM surface slowly diffuse back to the surface after cleaning, causing "whitening" or "oiling." 3. The Zn released during cleaning... 2+ / Ca 2+ In conjunction with hardness ions in the water, it reacts with fatty acid ions to regenerate insoluble soap scum, which then contaminates the surface of the hose again.

[0004] In the prior art, CN108085188A discloses a special cleaning agent for tire release agents, which uses a gasoline / kerosene solvent system combined with perfluorohexyl-n-octane to dissolve silicone oil. Although this solution is effective for pure silicone oil release agents, it has the following fundamental defects: 1. The solvent-based system is flammable and explosive, making it unsuitable for continuous production lines of automotive parts; 2. It cannot saponify and remove fatty acid metal soap films, resulting in low cleaning rates for composite release agents; 3. It contains persistent organic fluorine compounds, which do not meet environmental protection requirements; 4. Organic solvents may cause EPDM to swell. In addition, although conventional water-based alkaline cleaning agents can strongly saponify fatty acid soaps, they will severely damage the EPDM crosslinking network, leading to decreased hardness and a sticky surface. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a release agent cleaning agent for automotive cooling system hoses, a preparation method and a cleaning method, which can efficiently remove composite release agent residues on the surface of automotive cooling system hoses under mild conditions, while solving the problems of secondary deposition and substrate protection.

[0006] The present invention solves the above-mentioned technical problems through the following technical means:

[0007] In a first aspect, the present invention discloses a release agent and cleaning agent for automotive cooling system hoses, comprising, by mass parts, the following raw materials: 6-12 parts of fatty acid methyl ester ethoxylate (FMEE), 4-8 parts of narrow distribution isomeric tridecyl alcohol polyoxyethylene ether, 2-5 parts of α-olefin sulfonate (AOS), 1-3 parts of alkyl glucoside (APG), 2-5 parts of weak alkali saponification aid, 2-4 parts of chelating dispersant, and 0.2-0.6 parts of rubber protectant.

[0008] Furthermore, the EO addition number of the fatty acid methyl ester ethoxylate is 10~15; the narrow distribution isotactic tridecyl alcohol polyoxyethylene ether is a mixture of isotactic tridecyl alcohol polyoxyethylene ether-7EO (i.e., 1307) and isotactic tridecyl alcohol polyoxyethylene ether-9EO (i.e., 1309) in a mass ratio of (1~2):1.

[0009] Furthermore, the carbon chain length of the α-olefin sulfonate is C14~C18; the carbon chain length of the alkyl glucoside is C8~C14.

[0010] Furthermore, the weak alkaline saponification aid is composed of potassium carbonate and 2-amino-2-methyl-1-propanol (AMP-95) in a mass ratio of (2~3):2.

[0011] Furthermore, the chelating dispersant is composed of sodium polyaspartate and sodium gluconate in a mass ratio of (1~2):1; the rubber protectant is composed of cashew phenol polyoxyethylene ether and benzotriazole in a mass ratio of (2~3):1.

[0012] Furthermore, the number of EO additions of the fatty acid methyl ester ethoxylate is 12, the mass ratio of the isomeric tridecyl alcohol polyoxyethylene ether-7EO to the isomeric tridecyl alcohol polyoxyethylene ether-9EO is 1:1, and the mass ratio of the sum of the masses of the fatty acid methyl ester ethoxylate and the narrow distribution isomeric tridecyl alcohol polyoxyethylene ether to the mass of the α-olefin sulfonate is (3~4):1.

[0013] Furthermore, the mass ratio of potassium carbonate to 2-amino-2-methyl-1-propanol (AMP-95) in the weakly alkaline saponification aid is 3:2. This ratio ensures that the pH fluctuation of the working solution during the saponification and consumption of fatty acids does not exceed ±0.3.

[0014] Furthermore, the chelating dispersant comprises sodium polyaspartate (PASP) and sodium gluconate, wherein the weight-average molecular weight of sodium polyaspartate is 3000-5000, and after being compounded with sodium gluconate, it has a positive effect on Ca2+. 2+ The chelation capacity is ≥350mg CaCO3 / g.

[0015] Secondly, the present invention discloses a method for preparing the above-mentioned cleaning agent, comprising the following steps:

[0016] S1. Add deionized water to the reactor, heat to 50~60℃, add chelating dispersant and weak base saponification aid, stir at 200~400r / min until completely dissolved, to obtain premix A;

[0017] S2. Cool the premix A to 30~38℃, and add fatty acid methyl ester ethoxylate, narrow distribution isomeric tridecyl alcohol polyoxyethylene ether, α-olefin sulfonate and alkyl glucoside in sequence. Stir at 300~500r / min for 25~35 minutes to obtain mixture B.

[0018] S3. Add rubber protectant to mixture B, continue stirring for 10-15 minutes, cool to room temperature, filter, and the finished cleaning agent is obtained.

[0019] The core technical concept of this invention lies in constructing a three-in-one synergistic system of "microsaponification-micelle solubilization-chelation dispersion":

[0020] 1. Microsaponification module (weak alkaline saponification aid: potassium carbonate + AMP-95)

[0021] The pH of the working solution is precisely controlled between 8.5 and 9.2. Under these slightly alkaline conditions, potassium carbonate provides OH-. - This causes partial hydrolysis of fatty acid metal soaps, producing soluble fatty acid potassium salts and releasing Zn. 2+ / Ca 2+ AMP-95, as an organic base buffer, is used during saponification when OH groups are consumed. - The process involves continuous dissociation and replenishment to maintain pH stability (fluctuation ≤ ±0.3) and prevent localized excessive alkalinity from damaging the rubber. The key lies in "micro" incomplete saponification, which only softens and loosens the soap film, rather than completely decomposes it, thereby achieving soap film peeling without damaging the EPDM.

[0022] 2. Micellar solubilization module (FMEE + isomeric alcohol ether + AOS + APG)

[0023] FMEE (fatty acid methyl ester ethoxylate) contains ester groups in its molecular structure, similar to that of fatty acid soaps, allowing it to embed within the soap film and "loosen" it. Simultaneously, its long EO chain provides excellent solubilization for trace amounts of silicone oil. Narrowly distributed isomeric tridecyl alcohol polyoxyethylene ether 1307 / 1309 has a high cloud point (>75℃), and when combined with FMEE, it forms low CMC mixed micelles that can encapsulate silicone oil droplets and "remove" them from the surface. AOS provides anionic charge, creating electrostatic repulsion with the fatty acid anions generated by microsaponification, preventing their re-adsorption; APG reduces dynamic surface tension, promoting the penetration of cleaning solution into micropores.

[0024] 3. Chelation and dispersion module (sodium polyaspartate PASP + sodium gluconate)

[0025] PASP is a biodegradable, green chelating agent for Zn. 2+ / Ca 2+ / Mg 2+ Its chelating capacity is as high as 400mg CaCO3 / g or more, which can instantly capture the metal ions released by soap decomposition. Sodium gluconate helps disperse the detached dirt particles, preventing them from re-aggregating and depositing during the rinsing stage. The combination of the two forms a "capture-isolation-dispersion" chain, fundamentally eliminating the formation of secondary soap scum.

[0026] Thirdly, the present invention also discloses a cleaning method for the above-mentioned automotive cooling system hose release agent, including the following steps: when using it, the above-mentioned cleaning agent is diluted with deionized water 5 to 20 times, the working solution pH value is stabilized at 8.5 to 9.2, and the cleaning temperature is 40 to 80°C.

[0027] In summary, this application has the following beneficial effects:

[0028] 1. This invention achieves highly efficient removal of complex contaminants consisting of fatty acid soap films and trace amounts of silicone oil under weakly alkaline conditions through the spatiotemporal synergy of three sub-processes: "microsaponification, micellar solubilization, and chelation dispersion." The principle is as follows: a weakly alkaline saponification aid (potassium carbonate + AMP-95) precisely controls the pH of the working solution at 8.5~9.2, selectively and gently hydrolyzing the fatty acid metal soap, transforming the dense crystalline soap film into a loose, porous structure, opening channels for surfactant penetration; simultaneously, the low CMC mixed micelles formed by FMEE and isomeric alcohol ethers 1307 / 1309 simultaneously exert a solubilizing effect, encapsulating and removing loosened soap fragments and silicone oil droplets from the surface; the anionic charge provided by AOS prevents the re-adsorption of the solubilized contaminants. The three processes are not simply executed in a specific order, but occur simultaneously at the same time and in the same location, promoting each other and forming a complete chain of "micro-saponification and loosening → micellar solubilization and peeling → chelation and dispersion stabilization". This enables the composite release agent to achieve a cleaning rate of over 98%, which is significantly better than the effect of a single module or a combination of two modules.

[0029] 2. This invention, through the compounding of sodium polyaspartate (PASP) and sodium gluconate, cuts off the secondary soap scum formation chain at its source. The principle lies in the Zn released during the micro-saponification process. 2+ / Ca 2+ If the ions are not captured immediately, they will rapidly react with HCO3- in the water. - Incompletely saponified fatty acid ions may combine to form insoluble carbonates or fatty acid salts that deposit on the tubing surface. The densely packed carboxylate ions on the PASP molecular chain have an extremely strong chelating ability for divalent metal ions, with a complexation rate constant higher than that of Zn. 2+ With HCO3 - The reaction rate constant is three orders of magnitude higher than that of Zn.2+ Before it has a chance to participate in the precipitation reaction, it locks the free Zn in a stable chelated state; sodium gluconate, through steric hindrance, stably disperses the detached dirt particles in the aqueous phase, preventing them from re-aggregating. This triple protection mechanism of "kinetic priority capture + thermodynamic stabilization locking + dispersion isolation" ensures that the free Zn in the cleaning solution is effectively contained. 2+ The concentration was consistently below 0.5 ppm, and even under high-hardness water conditions of 500 ppm CaCO3, the secondary sedimentation was only 0.03 mg / cm², which is almost negligible.

[0030] 3. This invention achieves non-destructive compatibility with EPDM rubber substrates while ensuring cleaning efficiency through precise pH control and the combined action of a rubber protectant. The principle is that the cross-linking bonds in EPDM rubber are prone to breakage under strongly alkaline conditions (pH>11), leading to decreased hardness and surface stickiness. This invention strictly controls the pH of the working solution between 8.5 and 9.2, and the OH... - Concentration is only 10 -5 ~10 -6 The concentration of mol / L is far from sufficient to trigger the cross-linking bond breaking reaction. Simultaneously, cashew phenol polyoxyethylene ether, due to the structural similarity between its long alkyl chain and the amorphous region of EPDM, spontaneously forms a protective adsorption film of approximately 2-5 nm thickness on the rubber surface through hydrophobic interactions, effectively blocking further penetration of water molecules and ions. Benzotriazole, on the other hand, protects the internal metal reinforcement layer of the tubing from corrosion. Test results show that after 168 hours of immersion, the hardness change of the EPDM sample does not exceed 1 Shore A, the volume swelling rate does not exceed 1.2%, and the surface printing is clear and complete, far superior to the performance of traditional strong alkali formulations (hardness decrease of 5 degrees, swelling rate of 4.8%) and solvent-based formulations (swelling rate of 3.5%).

[0031] 4. This invention eliminates high-environmental-risk substances widely used in traditional cleaning agents, such as phosphates, halogenated hydrocarbons, perfluorinated compounds, and APEO, constructing a completely green formulation system. The principle is as follows: Sodium polyaspartate (PASP), a biodegradable sodium polyaspartate, replaces the traditional chelating agent sodium tripolyphosphate (STPP). PASP has a biodegradability of over 95%, avoiding the risk of eutrophication. Narrowly distributed isomeric tridecyl alcohol polyoxyethylene ether replaces nonylphenol polyoxyethylene ether (APEO). The former is a branched alcohol ether, with significantly better biodegradability and ecotoxicity than APEO. The formulation completely avoids the use of chlorine- and fluorine-containing organic solvents, eliminating the generation of persistent organic pollutants. All components are biodegradable organic matter, and their dosage is precisely optimized with no redundant additions. The COD value of the wastewater is only 2650 mg / L, less than two-thirds of that of traditional strong alkaline formulations (4200 mg / L), and far lower than solvent-based formulations (>8000 mg / L), significantly reducing the burden of wastewater treatment. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] Example 1

[0034] This embodiment describes a method for preparing a release agent and cleaning agent for automotive cooling system hoses, comprising the following steps:

[0035] Step S1: Preparation of premix A

[0036] Weigh 71.9 kg of deionized water according to the formula and add it to the reactor. Start the stirrer and set the speed to 300 r / min. Start the heating system and heat the deionized water to 55℃±2℃. Add 1.5 kg of sodium polyaspartate and 1.5 kg of sodium gluconate in sequence, and stir for 5 minutes until completely dissolved. Then add 1.8 kg of potassium carbonate and 1.2 kg of 2-amino-2-methyl-1-propanol, and continue stirring for 10 minutes until completely dissolved, to obtain a colorless and transparent premixed solution A.

[0037] Step S2: Preparation of Mixture B

[0038] Turn off the heating system and turn on the cooling circulation to cool premix A to 35℃±2℃. Add the surfactants in the following order: first, add 8.0 kg of fatty acid methyl ester ethoxylate and stir for 3 minutes; then add 2.5 kg of isotridecyl alcohol polyoxyethylene ether-7EO and stir for 2 minutes; then add 2.5 kg of isotridecyl alcohol polyoxyethylene ether-9EO and stir for 2 minutes; then add 3.5 kg of α-olefin sulfonate and stir for 3 minutes; finally, add 2.0 kg of alkyl glucoside and stir for 2 minutes. Adjust the stirring speed to 400 r / min and continue stirring for 30 minutes to obtain a uniform, transparent, slightly opalescent mixture B.

[0039] Step S3: Preparation of the finished cleaning agent

[0040] Add 0.3375 kg of cashew phenol polyoxyethylene ether and 0.1125 kg of benzotriazole to mixture B, and stir for 5 minutes. Turn off the stirrer, take a sample to test the pH value, and confirm that the pH value is within the range of 8.5~9.2. Turn on the cooling circulation to cool the material to below 25°C. Filter through a 200-mesh filter, fill into bottles, and obtain the finished cleaning agent.

[0041] Example 2

[0042] This embodiment describes a second method for preparing a release agent and cleaning agent for automotive cooling system hoses, comprising the following steps:

[0043] Step S1: Preparation of premix A

[0044] Weigh 83.35 kg of deionized water according to the formula and add it to the reactor. Start the stirrer and set the speed to 300 r / min. Start the heating system and heat the deionized water to 55℃±2℃. Add 1.0 kg of sodium polyaspartate and 1.0 kg of sodium gluconate in sequence, and stir for 5 minutes until completely dissolved. Then add 1.2 kg of potassium carbonate and 0.8 kg of 2-amino-2-methyl-1-propanol, and continue stirring for 10 minutes until completely dissolved, to obtain a colorless and transparent premixed solution A.

[0045] Step S2: Preparation of Mixture B

[0046] Turn off the heating system and turn on the cooling circulation to cool premix A to 35℃±2℃. Add the surfactants in the following order: first, add 5.0 kg of fatty acid methyl ester ethoxylate and stir for 3 minutes; then add 1.5 kg of isotridecyl alcohol polyoxyethylene ether-7EO and stir for 2 minutes; then add 1.5 kg of isotridecyl alcohol polyoxyethylene ether-9EO and stir for 2 minutes; then add 2.0 kg of α-olefin sulfonate and stir for 3 minutes; finally, add 1.0 kg of alkyl glucoside and stir for 2 minutes. Adjust the stirring speed to 400 r / min and continue stirring for 30 minutes to obtain a uniform, transparent, slightly opalescent mixture B.

[0047] Step S3: Preparation of the finished cleaning agent

[0048] Add 0.150 kg of cashew phenol polyoxyethylene ether and 0.050 kg of benzotriazole to mixture B, and stir for 5 minutes. Turn off the stirrer, take a sample to test the pH value, and confirm that the pH value is within the range of 8.5~9.2. Turn on the cooling circulation to cool the material to below 25°C. Filter through a 200-mesh filter, fill into bottles, and obtain the finished cleaning agent.

[0049] Example 3

[0050] This embodiment describes a third method for preparing a release agent and cleaning agent for automotive cooling system hoses, comprising the following steps:

[0051] Step S1: Preparation of premix A

[0052] Weigh 56.2 kg of deionized water according to the formula and add it to the reactor. Start the stirrer and set the speed to 300 r / min. Start the heating system and heat the deionized water to 55℃±2℃. Add 2.667 kg of sodium polyaspartate and 1.333 kg of sodium gluconate in sequence, and stir for 5 minutes until completely dissolved. Then add 3.0 kg of potassium carbonate and 2.0 kg of 2-amino-2-methyl-1-propanol, and continue stirring for 10 minutes until completely dissolved, to obtain a colorless and transparent premixed solution A.

[0053] Step S2: Preparation of Mixture B

[0054] Turn off the heating system and turn on the cooling circulation to cool premix A to 35℃±2℃. Add the surfactants in the following order: first, add 12.0 kg of fatty acid methyl ester ethoxylate and stir for 3 minutes; then add 4.0 kg of isotridecyl alcohol polyoxyethylene ether-7EO and stir for 2 minutes; then add 4.0 kg of isotridecyl alcohol polyoxyethylene ether-9EO and stir for 2 minutes; then add 5.0 kg of α-olefin sulfonate and stir for 3 minutes; finally, add 3.0 kg of alkyl glucoside and stir for 2 minutes. Adjust the stirring speed to 400 r / min and continue stirring for 30 minutes to obtain a uniform, transparent, slightly opalescent mixture B.

[0055] Step S3: Preparation of the finished cleaning agent

[0056] Add 0.450 kg of cashew phenol polyoxyethylene ether and 0.150 kg of benzotriazole to mixture B, and stir for 5 minutes. Turn off the stirrer, take a sample to test the pH value, and confirm that the pH value is within the range of 8.5~9.2. Turn on the cooling circulation to cool the material to below 25°C. Filter through a 200-mesh filter, fill into bottles, and obtain the finished cleaning agent.

[0057] Preparation steps of Comparative Example 1 (lacking microsaponification module)

[0058] Step S1: Preparation of premix A

[0059] Weigh 74.9 kg of deionized water according to the formula and add it to the reactor. Turn on the stirrer and set the speed to 300 r / min. Start the heating system and heat the deionized water to 55℃±2℃. Add 1.5 kg of sodium polyaspartate and 1.5 kg of sodium gluconate, and stir for 5 minutes until completely dissolved. Note: Do not add potassium carbonate and 2-amino-2-methyl-1-propanol; proceed directly to the next step to obtain premix A.

[0060] Step S2: Preparation of Mixture B

[0061] Turn off the heating system and turn on the cooling circulation to cool premix A to 35℃±2℃. Add the surfactants in the following order: first, add 8.0 kg of fatty acid methyl ester ethoxylate and stir for 3 minutes; then add 2.5 kg of isotridecyl alcohol polyoxyethylene ether-7EO and stir for 2 minutes; then add 2.5 kg of isotridecyl alcohol polyoxyethylene ether-9EO and stir for 2 minutes; then add 3.5 kg of α-olefin sulfonate and stir for 3 minutes; finally, add 2.0 kg of alkyl glucoside and stir for 2 minutes. Adjust the stirring speed to 400 r / min and continue stirring for 30 minutes to obtain mixture B.

[0062] Step S3: Preparation of the finished cleaning agent

[0063] Add 0.3375 kg of cashew phenol polyoxyethylene ether and 0.1125 kg of benzotriazole to mixture B, and stir for 5 minutes. Take a sample to test the pH value; it should be neutral or slightly acidic at this point. Slowly add triethanolamine dropwise while stirring, adjusting the pH to 8.8 ± 0.1. Turn on the cooling circulation to cool the material to below 25°C. Filter through a 200-mesh filter, and fill into vials to obtain the finished cleaning agent.

[0064] Preparation steps of Comparative Example 2 (lacking micelle solubilization module)

[0065] Step S1: Preparation of premix A

[0066] Weigh 93.8375 kg of deionized water according to the formula and add it to the reactor. Start the stirrer and set the speed to 300 r / min. Start the heating system and heat the deionized water to 55℃±2℃. Add 1.5 kg of sodium polyaspartate and 1.5 kg of sodium gluconate, and stir for 5 minutes until completely dissolved. Then add 1.8 kg of potassium carbonate and 1.2 kg of 2-amino-2-methyl-1-propanol, and continue stirring for 10 minutes until completely dissolved to obtain premix A.

[0067] Step S2: Preparation of Mixture B

[0068] Turn off the heating system and start the cooling circulation to cool premix A to 35℃±2℃. Note: Do not add any surfactants; proceed directly to the next step.

[0069] Step S3: Preparation of the finished cleaning agent

[0070] Add 0.3375 kg of cashew phenol polyoxyethylene ether and 0.1125 kg of benzotriazole to mixture B, and stir for 5 minutes. Take a sample to test the pH value; if necessary, adjust it to 8.5-9.2 with a small amount of potassium carbonate or triethanolamine. Turn on the cooling circulation to cool the material to below 25°C. Filter through a 200-mesh filter, fill into vials, and obtain the finished cleaning agent.

[0071] Preparation steps of Comparative Example 3 (lacking chelate dispersion module)

[0072] Step S1: Preparation of premix A

[0073] Weigh 74.9 kg of deionized water according to the formula and add it to the reactor. Turn on the stirrer and set the speed to 300 r / min. Start the heating system and heat the deionized water to 55℃±2℃. Note: Do not add sodium polyaspartate and sodium gluconate. Directly add 1.8 kg of potassium carbonate and 1.2 kg of 2-amino-2-methyl-1-propanol, and stir for 10 minutes until completely dissolved to obtain premix A.

[0074] Step S2: Preparation of Mixture B

[0075] Turn off the heating system and turn on the cooling circulation to cool premix A to 35℃±2℃. Add the surfactants in the following order: first, add 8.0 kg of fatty acid methyl ester ethoxylate and stir for 3 minutes; then add 2.5 kg of isotridecyl alcohol polyoxyethylene ether-7EO and stir for 2 minutes; then add 2.5 kg of isotridecyl alcohol polyoxyethylene ether-9EO and stir for 2 minutes; then add 3.5 kg of α-olefin sulfonate and stir for 3 minutes; finally, add 2.0 kg of alkyl glucoside and stir for 2 minutes. Adjust the stirring speed to 400 r / min and continue stirring for 30 minutes to obtain mixture B.

[0076] Step S3: Preparation of the finished cleaning agent

[0077] Add 0.3375 kg of cashew phenol polyoxyethylene ether and 0.1125 kg of benzotriazole to mixture B, and stir for 5 minutes. Take a sample to test the pH value, confirming it is within the range of 8.5-9.2. Start the cooling circulation to cool the material to below 25°C. Filter through a 200-mesh filter, and fill into vials to obtain the finished cleaning agent.

[0078] Preparation steps of Comparative Example 4 (traditional strong base formulation)

[0079] Step S1: Preparation of premixed solution

[0080] Weigh 89.5 kg of deionized water according to the formula and add it to the reactor. Start the stirrer and set the speed to 300 r / min. Start the heating system, add 0.5 kg of sodium hydroxide to the deionized water, and raise the temperature to 70℃±2℃. Stir until completely dissolved to obtain an alkaline solution.

[0081] Step S2: Addition of surfactant

[0082] Cool the alkaline solution to 50℃±2℃. Add 5.0 kg of OP-10 (octylphenol polyoxyethylene ether) and 3.0 kg of sodium dodecylbenzenesulfonate, and stir for 20 minutes until completely dissolved.

[0083] Step S3: Addition of chelating agent

[0084] Add 2.0 kg of sodium tripolyphosphate and continue stirring for 10 minutes until completely dissolved.

[0085] Step S4: Preparation of the finished cleaning agent

[0086] Turn off the heating system and start the cooling circulation to cool the material to below 25°C. Take a sample to test the pH value, confirming it to be approximately 12.5. Filter through a 200-mesh filter, fill into vials, and the finished cleaning agent is obtained.

[0087] Preparation steps of Comparative Example 5 (existing solvent-based formulation)

[0088] Step S1: Preparation of solvent base

[0089] In a fume hood, add 55.0 kg of No. 120 gasoline and 20.0 kg of kerosene to the reactor, turn on the stirrer at room temperature, set the speed to 200 r / min, and mix for 5 minutes.

[0090] Step S2: Addition of surfactant

[0091] Add 5.0 kg of sodium petroleum sulfonate to the solvent mixture and continue stirring for 10 minutes until completely dissolved.

[0092] Step S3: Addition of functional additives

[0093] Add 2.0 kg of perfluorohexyl n-octane and stir for 5 minutes. Then add 3.0 kg of hexamethylenetetramine and stir for 5 minutes until completely dissolved.

[0094] Step S4: Preparation of the finished product

[0095] Finally, add 15.0 kg of acetone and stir for 5 minutes until well mixed. Filter through a 200-mesh filter, fill into airtight containers, and store in a dark place. This product is flammable and must be labeled with a hazard warning sign and stored in a dedicated fireproof cabinet.

[0096] The cleaning agents of Examples 1-3 and Comparative Examples 1-5 were tested below, and the test methods are as follows:

[0097] (1) Preparation of composite release agent to simulate dirt

[0098] A simulated mold release agent was prepared by emulsifying 15g of zinc stearate (industrial grade), 0.5g of methyl silicone oil (viscosity 100cs), 2g of polyether L-61, and 82.5g of deionized water at high speed (10000r / min, 5 minutes) at 60℃.

[0099] The simulated release agent was evenly sprayed onto the surface of an EPDM specimen (50mm×50mm×2mm) at a rate of 0.2mL / cm². 2 .

[0100] Place the sprayed test piece in a 120℃ oven and dry for 30 minutes to allow the release agent to cure.

[0101] Weigh and record the initial weight W0 and the weight W1 after coating, and calculate the initial amount of dirt = W1 - W0 (controlled at 8~10mg / cm²).

[0102] (2) Cleaning rate determination

[0103] Dilute each cleaning agent concentrate with deionized water at a ratio of 1:15 and heat to 50℃±1℃.

[0104] Immerse the contaminated test piece in the cleaning solution and clean it with low-frequency ultrasonic waves (40kHz, 100W) for 3 minutes.

[0105] Remove the test piece and rinse it twice with 50℃ deionized water for 1 minute each time.

[0106] Place the test piece in a 110℃ oven and dry for 30 minutes.

[0107] Weigh and record the weight W2 after cleaning.

[0108] Cleaning rate (%) = (W1 - W2) / (W1 - W0) × 100%

[0109] (3) Measurement of secondary sedimentation

[0110] After cleaning and drying, place the test piece in a hard water rinsing tank containing 500 ppm CaCO3 and soak it at 50°C for 5 minutes.

[0111] Remove the test piece and let it air dry naturally for 24 hours.

[0112] Weigh and record the weight W3.

[0113] Secondary deposition amount (mg / cm²) = (W³ - W²) / sample area

[0114] (4) EPDM compatibility test

[0115] Immerse blank EPDM test pieces (without dirt) in the undiluted solutions of each cleaning agent and soak at 50℃±1℃ for 168 hours.

[0116] Remove the test piece, rinse it with deionized water, and let it air dry for 24 hours.

[0117] Test the change in hardness (Shore A) and volume swelling rate.

[0118] Volume swelling rate (%) = (V2 - V1) / V1 × 100%, where V1 is the volume before soaking and V2 is the volume after soaking.

[0119] (5) 48-hour whitening / oiling test

[0120] The cleaned test pieces were placed in a standard laboratory environment (25°C, RH 50%) for 48 hours.

[0121] Visually inspect the surface for white powdery substances (whitening) or an oily sheen (oiling).

[0122] Wipe the surface with a clean white cloth to check for any residue.

[0123] (6) Hard water stability test

[0124] Dilute each cleaning agent concentrate with deionized water at a ratio of 1:15, and then add CaCl2 solution to make the CaCO3 concentration 500ppm.

[0125] Let it stand at 50℃ for 24 hours and observe whether turbidity, layering, or precipitation occurs.

[0126] (7) COD determination

[0127] Take 1 mL of each cleaning agent stock solution, dilute to 1000 mL, and determine the chemical oxygen demand (COD) according to the method of GB / T 11914-1989.

[0128] During cleaning, take the prepared cleaning agent stock solutions and dilute them with deionized water at a ratio of 1:15. After stirring evenly, heat to 50℃±1℃. Completely immerse the EPDM cooling tubing sample with residual composite release agent into the cleaning working solution, supplemented with low-frequency ultrasonic cleaning (frequency 40kHz, power 100W) for 3 minutes. Remove the sample and immediately rinse it in deionized water at 50℃±1℃ for 1 minute, then rinse again with fresh deionized water for 1 minute. Place the rinsed sample in a 110℃ oven to dry for 30 minutes, then remove and cool to room temperature to complete the entire cleaning process.

[0129] The final data is as follows:

[0130]

[0131] As can be seen from the data in the above embodiments:

[0132] 1. By comparing the cleaning rate data of Example 1 with the three comparative examples lacking the module, the existence of the three-in-one synergistic mechanism of "microsaponification-micelle solubilization-chelation dispersion" can be clearly verified. The cleaning rate of Example 1 (complete system) reached 98.6%, while the cleaning rate of Comparative Example 1 (lacking the microsaponification module) dropped to 72.3%, the cleaning rate of Comparative Example 2 (lacking the micellar solubilization module) plummeted to 41.5%, and the cleaning rate of Comparative Example 3 (lacking the chelation dispersion module) was 86.8%. The reasons for this are as follows: In Comparative Example 1, there was no weak base saponification aid to pre-soften the fatty acid soap film, and the surfactant alone could not penetrate the dense soap film crystal layer, so the cleaning rate dropped significantly; In Comparative Example 2, there was only saponification without the solubilization and emulsification of surfactant, and the saponification products could not be effectively dispersed and removed, resulting in the lowest cleaning rate; Although the cleaning rate of Comparative Example 3 was higher than that of Comparative Examples 1 and 2, it was still significantly lower than that of Example 1, indicating that the chelation dispersion module not only prevents secondary deposition but also indirectly improves the cleaning efficiency by stabilizing the detached dirt particles. Further quantitative analysis of the synergistic effect revealed a positive synergistic effect among the three modules, rather than a simple additive effect. The synergistic mechanism is as follows: microsaponification creates channels for micellar solubilization, micellar solubilization provides a target for chelation dispersion, and chelation dispersion, in turn, prevents dirt from re-clogging the surface, forming a self-reinforcing positive cycle.

[0133] 2. By comparing the secondary deposition data of Example 1 with Comparative Examples 3 and 4, the significant advantage of this invention in suppressing secondary deposition can be demonstrated. The secondary deposition in Example 1 was only 0.03 mg / cm², almost negligible, and no whitening or oiling occurred after 48 hours. Comparative Example 3 (lacking the chelating module) had a secondary deposition as high as 1.63 mg / cm², the highest among all comparative examples, and slight oiling occurred after 48 hours. This indicates that without the chelating and dispersing effects of sodium polyaspartate and sodium gluconate, the zinc and calcium ions released by saponification quickly combine with bicarbonate ions or incompletely saponified fatty acid ions in the water, forming insoluble soap scum that redeposits on the tube surface. Comparative Example 4 (traditional strong alkali formulation) had a secondary deposition of 0.94 mg / cm², and the surface was sticky, indicating that although the strong alkali can strongly saponify, it cannot effectively chelate metal ions, and the secondary deposition problem remains serious. Comparative Example 5 (solvent-based formulation) showed a relatively low secondary deposition rate of 0.28 mg / cm², but it relied on the dissolving effect of organic solvents rather than a chelation mechanism, posing serious environmental and safety issues. Based on the above data, it can be concluded that the triple protection mechanism of "kinetic priority capture, thermodynamic stability locking, and dispersion isolation" composed of sodium polyaspartate and sodium gluconate is a key technical means to cut off the secondary soap scum formation chain at its source.

[0134] 3. By comparing the EPDM compatibility data of Example 1 with Comparative Examples 4 and 5, the significant advantages of this invention in protecting rubber substrates can be demonstrated. In Example 1, the EPDM hardness change was only +1 Shore A, the volume swelling rate was only 1.0%, and the surface condition remained intact. Comparative Example 4 (a traditional strong alkali formulation, pH approximately 12.5) resulted in a 5-degree decrease in EPDM hardness, a volume swelling rate as high as 4.8%, and a sticky surface. This is because under strong alkali conditions, the hydroxide ion concentration is as high as 10⁻¹ to 10⁻² mol / L, sufficient to trigger the β-breakage reaction of EPDM crosslinking bonds, leading to a decrease in crosslinking density and rubber softening. Comparative Example 5 (a solvent-based formulation) showed a 3-degree increase in hardness and a swelling rate of 3.5%, indicating that organic solvents (gasoline, kerosene) penetrated the amorphous regions of EPDM, causing swelling and plasticization, thus altering the mechanical properties of the rubber. This invention precisely controls the pH value between 8.5 and 9.2, with a hydroxide ion concentration of only 10⁻⁵ to 10⁻⁶ mol / L, far from sufficient to trigger the breaking reaction of cross-linking bonds. Simultaneously, cashew phenol polyoxyethylene ether, due to the structural similarity between its long alkyl chain and the amorphous region of EPDM, spontaneously forms a protective adsorption film approximately 2 to 5 nanometers thick on the rubber surface through hydrophobic interactions, effectively preventing further penetration of water molecules and ions. Based on the above analysis, it can be concluded that the combined effect of weakly alkaline pH control and cashew phenol-based protective agents is the core technical means to achieve non-destructive compatibility of EPDM.

[0135] 4. By comparing the environmental performance data of Example 1 with Comparative Examples 4 and 5, the comprehensive leading advantage of this invention in environmental compliance can be demonstrated. Example 1 has a COD value of only 2650 mg / L, and the formulation contains no phosphates, halogenated hydrocarbons, APEOs, perfluorinated compounds, or volatile organic compounds. Comparative Example 4 (traditional strong alkali formulation) has a COD value of 4250 mg / L and contains sodium tripolyphosphate (which causes eutrophication) and OP-10 (an APEO-type endocrine disruptor). Comparative Example 5 (solvent-based formulation) has a COD value exceeding 8000 mg / L and contains large amounts of volatile organic compounds and perfluorinated compounds (persistent organic pollutants). This invention replaces the traditional chelating agent sodium tripolyphosphate with biodegradable sodium polyaspartate. Sodium polyaspartate achieves a biodegradability of over 95%, avoiding the risk of eutrophication. It replaces nonylphenol polyoxyethylene ether with narrow-distribution isomeric tridecyl alcohol polyoxyethylene ether; the former, being a branched alcohol ether, exhibits significantly better biodegradability and ecotoxicity than APEO. The formulation completely avoids the use of chlorine- and fluorine-containing organic solvents, eliminating the generation of persistent organic pollutants. All components are biodegradable organic compounds, and their dosages are precisely optimized with no redundant additions. Based on the above analysis, it can be concluded that this invention represents a significant technological advancement in the construction of a fully green formulation system and possesses a clear advantage in environmental compliance.

[0136] 5. By comparing the performance data of Examples 1, 2, and 3 at different concentration levels, the rationality of the formulation parameter range and the process stability of the present invention can be verified. Example 2 (low concentration formulation, total active ingredient content approximately 14.65%) had a cleaning rate of 95.3% and a secondary deposition amount of 0.08 mg / cm²; Example 1 (medium concentration formulation, total active ingredient content approximately 21.44%) had a cleaning rate of 98.6% and a secondary deposition amount of 0.03 mg / cm²; Example 3 (high concentration formulation, total active ingredient content approximately 32.77%) had a cleaning rate of 99.1% and a secondary deposition amount of 0.02 mg / cm². With increasing formulation concentration, the cleaning rate increased from 95.3% to 99.1%, and the secondary deposition amount decreased from 0.08 mg / cm² to 0.02 mg / cm², showing a clear dose-response relationship. It is noteworthy that the cleaning rate of Example 2 (low concentration) reached 95.3%, indicating that even at lower concentrations, the synergistic mechanism remains effective. The difference in cleaning rate between Example 1 and Example 3 was only 0.5 percentage points, indicating that the marginal benefit of further increasing the concentration diminishes after a certain level is reached. Based on the above analysis, it can be concluded that Example 1 (intermediate formulation) achieves the optimal balance between cleaning efficiency, secondary deposition inhibition, and raw material cost, making it the most cost-effective choice. This also demonstrates that the formulation parameter range of this invention is reasonably designed and the process is stable and reliable.

[0137] In summary, based on the experimental design and data analysis of the above embodiments, the following overall conclusions can be drawn. First, the three-in-one synergistic mechanism is fully verified: the cleaning rate of Example 1 (complete system) reached 98.6%, significantly higher than the comparative example lacking any one module. The simultaneous presence of all three modules produced a synergistic effect, proving the scientific validity and effectiveness of the "microsaponification-micelle solubilization-chelation dispersion" three-in-one mechanism. Second, the secondary deposition problem is fundamentally solved: the secondary deposition amount in Example 1 was only 0.03 mg / cm², with no whitening or oiling after 48 hours, while the secondary deposition amount in Comparative Example 3 (lacking the chelation module) was as high as 1.63 mg / cm² and oiling occurred. This proves that the chelation dispersion system of sodium polyaspartate and sodium gluconate is key to preventing secondary soap scum formation. Third, the EPDM compatibility is significantly superior to existing technologies: Example 1's effect on EPDM hardness is only +1 Shore A, and the volume swelling rate is only 1.0%, far superior to traditional strong alkaline formulations (hardness decrease of 5 degrees, swelling rate of 4.8%) and solvent-based formulations (hardness increase of 3 degrees, swelling rate of 3.5%). The combined effect of weak alkaline pH control and cashew phenol-based protective agent is the core of achieving non-destructive compatibility. Fourth, the environmental performance is comprehensively superior: Example 1 has a COD value of only 2650 mg / L, and the formulation does not contain phosphates, APEO, perfluorinated compounds, or volatile organic compounds, showing a significant advantage in environmental compliance. Fifth, the formulation parameters are reasonable and the process is feasible: The concentration gradient experiments of Examples 1 to 3 show that the formulation can maintain good cleaning effect and secondary deposition inhibition ability at low, medium, and high concentration levels, indicating that the formulation parameter range of the present invention is reasonably designed and the process is stable and reliable.

[0138] Therefore, this invention successfully solves the three major technical problems of "layered adhesion of composite dirt", "delayed release of microporous residue" and "secondary soap deposit in hard water" in the cleaning of composite release agent residue on the surface of EPDM hoses in automotive cooling systems through a three-in-one synergistic mechanism of "microsaponification-micelle solubilization-chelation dispersion". It achieves a unity of efficient cleaning, substrate protection and environmental compliance, and has significant industrial practical value.

[0139] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention. Technical aspects, shapes, and structures not described in detail in this invention are all well-known technologies.

Claims

1. A release agent and cleaning agent for automotive cooling system hoses, characterized in that, By mass, it includes the following raw materials: 6-12 parts of fatty acid methyl ester ethoxylate, 4-8 parts of narrow distribution isomeric tridecyl alcohol polyoxyethylene ether, 2-5 parts of α-olefin sulfonate, 1-3 parts of alkyl glucoside, 2-5 parts of weak base saponification aid, 2-4 parts of chelating dispersant, and 0.2-0.6 parts of rubber protectant.

2. The automotive cooling system hose release agent and cleaning agent according to claim 1, characterized in that, The EO addition number of the fatty acid methyl ester ethoxylate is 10~15; the narrow distribution isotretinoin polyoxyethylene ether is a mixture of isotretinoin polyoxyethylene ether-7EO and isotretinoin polyoxyethylene ether-9EO in a mass ratio of (1~2):

1.

3. The automotive cooling system hose release agent and cleaning agent according to claim 1, characterized in that, The α-olefin sulfonate has a carbon chain length of C14 to C18; the alkyl glucoside has a carbon chain length of C8 to C14.

4. The automotive cooling system hose release agent and cleaning agent according to claim 1, characterized in that, The weak alkaline saponification aid is composed of potassium carbonate and 2-amino-2-methyl-1-propanol in a mass ratio of (2~3):

2.

5. The automotive cooling system hose release agent and cleaning agent according to claim 1, characterized in that, The chelating dispersant is composed of sodium polyaspartate and sodium gluconate in a mass ratio of (1~2):1; the rubber protectant is composed of cashew phenol polyoxyethylene ether and benzotriazole in a mass ratio of (2~3):

1.

6. The automotive cooling system hose release agent and cleaning agent according to claim 1, characterized in that, The EO addition number of the fatty acid methyl ester ethoxylate is 12, the mass ratio of the isomeric tridecyl alcohol polyoxyethylene ether-7EO to the isomeric tridecyl alcohol polyoxyethylene ether-9EO is 1:1, and the mass ratio of the sum of the masses of the fatty acid methyl ester ethoxylate and the narrow distribution isomeric tridecyl alcohol polyoxyethylene ether to the mass of the α-olefin sulfonate is (3~4):

1.

7. The automotive cooling system hose release agent and cleaning agent according to claim 1, characterized in that, The mass ratio of potassium carbonate to 2-amino-2-methyl-1-propanol in the weak base saponification aid is 3:

2.

8. The automotive cooling system hose release agent and cleaning agent according to claim 1, characterized in that, The chelating dispersant comprises sodium polyaspartate and sodium gluconate, wherein the weight-average molecular weight of sodium polyaspartate is 3000-5000, and after being compounded with sodium gluconate, it has a positive effect on Ca2+. 2+ The chelation capacity is ≥350mg CaCO3 / g.

9. A method for preparing a release agent and cleaning agent for automotive cooling system hoses, characterized in that, The preparation of the cleaning agent according to any one of claims 1 to 8 comprises the following steps: S1. Add deionized water to the reactor, heat to 50~60℃, add chelating dispersant and weak base saponification aid, stir at 200~400r / min until completely dissolved, to obtain premix A; S2. Cool the premix A to 30~38℃, and add fatty acid methyl ester ethoxylate, narrow distribution isomeric tridecyl alcohol polyoxyethylene ether, α-olefin sulfonate and alkyl glucoside in sequence. Stir at 300~500r / min for 25~35 minutes to obtain mixture B. S3. Add rubber protectant to mixture B, continue stirring for 10-15 minutes, cool to room temperature, filter, and the finished cleaning agent is obtained.

10. A method for cleaning release agents from automotive cooling system hoses, characterized in that, When using the cleaning agent as described in any one of claims 1 to 8, dilute it with deionized water by 5 to 20 times, keep the pH value of the working solution stable at 8.5 to 9.2, and keep the cleaning temperature at 40 to 80°C.

Images