A long-term stable cationic sizing agent, its preparation method and application
By introducing a quaternary ammonium salt containing aromatic esters and a cationic surfactant into the cationic rolling fluid, the problem of easy failure of the cationic rolling fluid during long-term use was solved, and the stability, lubricity and rust prevention were improved, while reducing costs and management difficulty.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- QUAKER CHEM CHINA
- Filing Date
- 2026-03-31
- Publication Date
- 2026-06-02
AI Technical Summary
Existing cationic rolling fluids are prone to failure during long-term use, leading to the collapse of the emulsion system and affecting lubrication and cooling effects. Furthermore, existing improvement methods are costly or have difficulty in controlling stability.
Aromatic ester-containing quaternary ammonium salts are used as decoy molecules in combination with cationic surfactants to attract and capture impurities, protect the cationic surfactants, maintain system stability, and enhance antibacterial and anti-rust properties.
This approach achieves long-term stability of cationic rolling fluid, improves lubrication and rust prevention performance, while reducing synthesis costs and management complexity, and avoiding negative impacts.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of cold-rolled steel technology, and in particular to a long-term stable cationic rolling fluid, its preparation method, and its application. Background Technology
[0002] Cold rolling is a crucial finishing process in the modern steel industry, bridging upstream and downstream processes. It integrates machinery, metallurgy, and automation control, using hot-rolled products as raw materials to produce high-value-added steel through a series of precise and continuous steps. A complete cold rolling process typically includes pickling, cold rolling, annealing, and finishing. This process allows us to obtain thinner strip steel with excellent surface quality, precise thickness, and superior sheet shape. Cold rolling has become a cornerstone technology supporting the development of manufacturing industries such as automobiles, high-end home appliances, and precision instruments.
[0003] The core cold rolling process involves feeding the hot-rolled, pickled coil into a cold rolling mill at room temperature. Under intense pressure, the strip passes through one or more pairs of rolls, significantly reducing its thickness. Rolling oil is an indispensable process medium in this process; it is not merely a "lubricant," but a complex chemical system integrating lubrication, cooling, cleaning, and rust prevention, directly determining rolling efficiency, cost, product quality, and equipment lifespan. "Catonic rolling oil" is widely used in the market due to its excellent mill cleaning properties. This type of rolling oil uses cationic emulsifiers (usually amine derivatives) as the main surfactant. Its core structure can be summarized as a hydrophilic, positively charged head group plus one or more long-chain ethoxylated structural units (EO) at the tail. However, in long-term cyclic use in the field, the positively charged portion of the cationic surfactant in the emulsion easily combines with free acids or negatively charged impurities in the system, thus failing. The most direct manifestation is oil-water separation in the emulsion, preventing the formation of a uniform and stable emulsion, leading to the loss of its fundamental function.
[0004] Clearly, cationic emulsifiers are the core of cationic rolling fluids. If they fail on the rolling mill, the entire emulsion system collapses, leading to lubrication and cooling failures, and severe defects on the strip surface. It also damages the rolls and clogs the system, severely impacting production quality, equipment safety, and operating costs. Typically, to address these issues, the only solution is to add additives to maintain emulsion performance, but this incurs significant losses in manpower and costs, making it an unsustainable long-term solution.
[0005] CN106987300A discloses a maintenance-free polymeric cationic metal rolling fluid and its preparation method. While maintaining the high lubricity, high cleanliness, and low oil consumption characteristics of traditional cationic metal rolling fluids, it overcomes the problem of easy aging during long-term operation. This technology uses a styrene-block-(acrylamide-alter-dimethylaminomethylacrylamide) copolymer to replace the traditional cationic monomer surfactant. The advantage of this type of polymeric cationic fluid is that it can prevent reactions through large steric hindrance, preventing oil droplet aggregation and stratification, and the dense polymer film also has the potential to improve lubrication. However, its disadvantages are also obvious. For example, the synthesis cost is much higher than that of small molecule products, and the overly stable emulsion makes post-rolling wastewater treatment more difficult, increasing environmental treatment costs; it significantly increases the overall viscosity of the emulsion, leading to filter bag clogging; and its polymer chains are shortened and broken down by high-shear pump circulation during field use, causing performance degradation.
[0006] CN117343780A discloses a carbon steel rolling oil with a highly stable and dispersible emulsion system. It employs a combination of nonionic and cationic compound emulsifiers to improve the stability and dispersibility of the emulsion. The cationic compound emulsifier compensates for the lack of dispersibility exhibited by the nonionic compound emulsifier, while the nonionic emulsifier can still exert a certain emulsifying effect after the cationic emulsifier has deteriorated. However, this compounding method requires extremely stringent proportions. Stability does not increase with increasing nonionic proportions; instead, an optimal ratio needs to be determined through extensive experimentation. Otherwise, the stability may be lower than that of a single cationic emulsion system. Furthermore, excessive nonionic surfactants can interfere with the dense adsorption film of cationic surfactants on the strip surface, weakening its unique rust-preventive properties. Simultaneously, since this method does not protect the cationic surfactants, when the cationic surfactants eventually deteriorate, the nonionic system acting alone will also lose its dispersibility, resulting in poor emulsion dispersion.
[0007] In summary, compared to traditional cationic rolling oil systems, the two methods described above have significant drawbacks, namely high initial synthesis costs and difficulty in determining the addition ratio. Furthermore, both methods generate additional negative effects during use, greatly increasing the risks in the field. Therefore, there is a need to develop a method with lower synthesis difficulty, lower R&D costs, and more controllable risks to help achieve long-term stability of cationic rolling solutions. Summary of the Invention
[0008] To address the aforementioned technical problems, this invention provides a long-term stable cationic rolling fluid, its preparation method, and its application. The long-term stable cationic rolling fluid utilizes a low-cost, aromatic ester-containing quaternary ammonium salt as a "decoy molecule," enabling it to maintain system stability effectively during long-term field use while also exhibiting good rust prevention, lubrication, and antibacterial properties.
[0009] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a long-term stable cationic rolling solution, the long-term stable cationic rolling solution comprising the following components in parts by weight: 80-95 parts base oil; Extreme pressure agent 1.0-5.0 parts; Antioxidant 0.5-1.0 parts; 0.5-2.0 parts of cationic surfactant; 0.1-1.0 parts of quaternary ammonium salt containing aromatic esters.
[0010] The aromatic ester-containing quaternary ammonium salt provided by this invention can withstand most chemical attacks. Introduced as a "decoy molecule" into the cationic rolling fluid, it acts as a sacrificial agent, effectively attracting impurity molecules and creating a safer environment for the cationic surfactant to perform its core function. This efficiently prevents the cationic surfactant in the cationic rolling fluid from failing. Furthermore, by combining a specific amount of the aromatic ester-containing quaternary ammonium salt with the cationic surfactant, when a hydrolytic environment is formed, the acid preferentially attacks the more sensitive ester bonds on the decoy molecules. When negatively charged impurities attack the cationic surfactant, they are preferentially captured by the more numerous and strongly charged decoy molecules, thus achieving long-term stability of the cationic rolling fluid and effectively solving the problem of system collapse after long-term use of the cationic rolling fluid in the field. Moreover, the addition of this decoy molecule does not introduce any negative impact on the original rolling fluid system, nor does it increase the difficulty of on-site management, thus well meeting the needs of the on-site rolling process. Simultaneously, the addition of the decoy molecule also increases the antibacterial and anti-rust properties of the resulting cationic rolling fluid, further extending its service life.
[0011] The base oil in the long-term stable cationic rolling fluid provided by this invention can be 80 parts, 81 parts, 82 parts, 83 parts, 84 parts, 85 parts, 86 parts, 87 parts, 88 parts, 89 parts, 90 parts, 92 parts, or 95 parts by weight, as well as specific values between the above-mentioned values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific values included in the range.
[0012] The extreme pressure agent in the long-term stable cationic rolling solution provided by the present invention can be 1.0 part, 1.5 part, 2 part, 2.5 part, 3 part, 3.5 part, 4 part, 4.5 part or 5.0 part by weight, as well as specific values between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values included in the range.
[0013] The antioxidant in the long-term stable cationic rolling solution provided by this invention can be 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, 0.8 parts, 0.85 parts, 0.9 parts, 0.95 parts, or 1.0 parts by weight, as well as specific values between the above-mentioned values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific values included in the range.
[0014] The weight percentage of the cationic surfactant in the long-term stable cationic rolling solution provided by this invention can be 0.5 parts, 0.8 parts, 1.0 parts, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, or 2.0 parts, as well as specific values between the above-mentioned values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific values included in the range.
[0015] The weight parts of the quaternary ammonium salt containing aromatic esters in the long-term stable cationic rolling solution provided by the present invention can be 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, 0.8 parts, 0.85 parts, 0.9 parts, 0.95 parts, or 1.0 parts, as well as specific values between the above-mentioned values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values included in the range.
[0016] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.
[0017] As a preferred embodiment of the present invention, the mass ratio of the aromatic ester-containing quaternary ammonium salt to the cationic surfactant is (0.1-0.5):1, wherein (0.1-0.5) can be, for example, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 or 0.5, and specific values between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values included in the range.
[0018] This invention optimizes the mass ratio of aromatic ester-containing quaternary ammonium salt to cationic surfactant, ensuring that the decoy molecules are sufficient to cover the expected impurity load while leaving a safe margin, without affecting the core physicochemical properties of the original system. When the mass ratio of the two is low, the content of aromatic ester-containing quaternary ammonium salt is low, resulting in poor overall performance of the cationic rolling fluid, including aging resistance, lubrication, rust prevention, and antibacterial properties. Furthermore, when the content of aromatic ester-containing quaternary ammonium salt is too low (below 0.1 parts), the protection formed is weak, and the attackers in the aqueous phase will quickly consume a small amount of sacrificial agent (aromatic ester-containing quaternary ammonium salt), thus restarting the attack on the main surfactant (cationic surfactant). The protective effect under this condition is not durable during long-term rolling, requiring frequent maintenance of the rolling fluid system in the field.
[0019] When the mass ratio of the two is too high, the content of quaternary ammonium salt containing aromatic esters is too high. At this time, the excessive bait molecules (quaternary ammonium salt containing aromatic esters) will compete with the main surfactant (cationic surfactant) at the interface, thereby affecting the full performance of the main surfactant. It will also make the emulsion too stable, thus affecting the oil film thickness, resulting in a smaller average film thickness and poorer lubrication performance. At the same time, when the content of quaternary ammonium salt containing aromatic esters is too high, micelles are easily formed, which encapsulate the active part and reduce the effective concentration, thus weakening the antibacterial properties of the resulting rolling fluid. In addition, excessive quaternary ammonium salt containing aromatic esters can also easily form a disordered multilayer film on the metal surface, which is loose and unstable and cannot effectively protect the metal surface, thus reducing the corrosion resistance of the resulting rolling fluid.
[0020] Preferably, the aromatic ester-containing quaternary ammonium salt has the following structure: ; Where n is an integer selected from 11 to 17, for example, it can be 11, 12, 13, 14, 15, 16 or 17.
[0021] The aromatic ester-containing quaternary ammonium salt provided by this invention has a highly reactive unit. Its molecular structure contains an easily hydrolyzed ester group as a "sacrificial target," and a strong cationic head group that has a strong attraction to negatively charged impurities (such as fatty acids and bacterial cell membranes). It can preferentially react with acidic impurities in the emulsion, thereby more efficiently protecting the cationic surfactant. Furthermore, its molecular structure also contains a moderately hydrophobic chain, which allows the molecule to dissolve in the emulsion system without possessing optimal surface activity, thus not affecting the emulsifying properties of the rolling fluid itself. Moreover, the aromatic ester-containing quaternary ammonium salt has a small molecular structure, which will not affect the viscosity of the rolling fluid system and will not pose a risk of increasing the pressure on the filtration system or the difficulty of waste liquid treatment. In addition, the aromatic ester-containing quaternary ammonium salt will not weaken the anti-rust performance or introduce foaming problems like compounded nonionic surfactants, and will not produce negative effects in field use. At the same time, it does not require extensive experiments to determine the addition ratio, and does not have the disadvantage of negative effects caused by unsuitable compounding, thus allowing for more flexible use conditions.
[0022] This invention, by limiting the length of the hydrophobic carbon chain of the quaternary ammonium salt containing aromatic esters, can further improve the solubility of decoy molecules at the oil-water interface. A suitable hydrophobic carbon chain length allows the decoy molecules to be better enriched at the interface, thus providing sufficient affinity to closely adhere to and protect the active surface of the host cation. When the hydrophobic carbon chain is too short or too long, the aging resistance and lubrication performance of the resulting cationic rolling solution decrease. Furthermore, a shorter hydrophobic carbon chain results in weak adsorption at the oil / bacteria interface, reducing the antibacterial properties of the cationic rolling solution; a longer hydrophobic carbon chain weakens its chelation effect with free metal ions in the aqueous phase, reducing the rust-preventive properties of the cationic rolling solution.
[0023] Furthermore, when the hydrophobic carbon chain is too short, the decoy molecules will mostly dissolve in water during use. Although they can combine and react with some harmful substances, they cannot effectively approach the cationic surfactants that are mainly present at the oil-water interface, thus failing to effectively resist the "attacks" from the surrounding surfactant molecules. They will also be consumed too quickly in water. When the hydrophobic carbon chain is too long, the molecules will be strongly lipophilic, and the reaction rate with more attackers present in the aqueous phase will be extremely slow, failing to effectively protect the cationic surfactants. In this case, the main surfactant (cationic surfactant) will still be exposed to the attack and will not be able to play its role as a decoy molecule effectively.
[0024] Preferably, the aromatic ester-containing quaternary ammonium salt is a hydroxyethylalkyl quaternary ammonium salt of salicylic acid.
[0025] The salicylic acid hydroxyethyl alkyl quaternary ammonium salt provided in this invention has an ortho-hydroxy structure, which makes the aromatic ester-containing quaternary ammonium salt more reactive when attacked by acidic or negatively charged impurities. Furthermore, the ortho-hydroxybenzoic acid ester group (salicylic acid ester moiety) has excellent corrosion inhibition properties as well as antibacterial properties, and can thus play a synergistic role with the quaternary ammonium salt group, further broadening the antibacterial spectrum and antibacterial efficiency of the obtained long-term stable cationic rolling solution.
[0026] Preferably, the aromatic ester-containing quaternary ammonium salt is prepared by a first-stage reaction of hydroxybenzoic acid and N,N-dimethylethanolamine, followed by a second-stage reaction with a straight-chain haloalkane.
[0027] The molecular synthesis route for quaternary ammonium salts containing aromatic esters provided by this invention has the advantages of simple synthesis, convenient operation, and low preparation cost compared with the existing polymeric cationic surfactants.
[0028] Preferably, the hydroxybenzoic acid includes salicylic acid, p-hydroxybenzoic acid, or m-hydroxybenzoic acid.
[0029] Preferably, the molar ratio of hydroxybenzoic acid to N,N-dimethylethanolamine is 1:(1-1.3), wherein (1-1.3) can be 1, 1.02, 1.05, 1.08, 1.1, 1.12, 1.15, 1.18, 1.2, 1.22, 1.25, 1.28 or 1.3, as well as specific values between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values included in the range.
[0030] Preferably, the first stage reaction is carried out under the presence of an activator.
[0031] Preferably, the molar ratio of the activator to hydroxybenzoic acid is (1.05-1.10):1, wherein (1.05-1.10) can be, for example, 1.05, 1.06, 1.07, 1.08, 1.09 or 1.10, and specific values between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values included in the range.
[0032] Preferably, the activator comprises dicyclohexylcarbodiimide.
[0033] Preferably, the first stage reaction is carried out under a catalyst.
[0034] Preferably, the molar ratio of the catalyst to hydroxybenzoic acid is (0.1-0.2):1, wherein (0.1-0.2) can be, for example, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19 or 0.2, and specific values between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values included in the range.
[0035] Preferably, the catalyst comprises 4-dimethylaminopyridine.
[0036] Preferably, the first stage reaction is carried out in an organic solvent 1, which includes toluene.
[0037] Preferably, the first stage reaction is carried out under reflux.
[0038] Preferably, the intermediate obtained from the first stage reaction needs to be dried before the second stage reaction.
[0039] Preferably, the drying process includes vacuum concentration.
[0040] Preferably, the molar ratio of the straight-chain haloalkane to hydroxybenzoic acid is (1.3-1.7):1, wherein (1.3-1.7) can be 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65 or 1.7, and specific values between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values included in the range.
[0041] Preferably, the straight-chain haloalkane comprises C12-C18 straight-chain haloalkane, wherein C12-C18 can be C12, C13, C14, C15, C16, C17 or C18.
[0042] Preferably, the second stage reaction is carried out in an organic solvent 2, which includes acetonitrile.
[0043] Preferably, the temperature of the second stage reaction is 75-85℃, for example, it can be 75℃, 76℃, 77℃, 78℃, 79℃, 80℃, 81℃, 82℃, 83℃, 84℃ or 85℃, as well as specific values between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values included in the range.
[0044] Preferably, the reaction time of the second stage is 12-24 h, for example, it can be 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, 19 h, 20 h, 21 h, 22 h, 23 h or 24 h, as well as specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific point values included in the range.
[0045] Preferably, both the first-stage reaction and the second-stage reaction are carried out under a protective gas atmosphere.
[0046] Preferably, the protective gas includes any one or a combination of at least two of nitrogen, argon, or helium.
[0047] Preferably, the second stage reaction further includes a post-processing step.
[0048] Preferably, the post-processing method includes drying and recrystallization.
[0049] Preferably, the drying method includes vacuum distillation.
[0050] Preferably, the recrystallization is carried out in a recrystallization solvent.
[0051] Preferably, the recrystallization solvent includes ethyl acetate and ethanol.
[0052] For example, the method for preparing quaternary ammonium salts containing aromatic esters provided by the present invention specifically includes the following steps: Hydroxybenzoic acid, N,N-dimethylethanolamine, and organic solvent 1 were mixed, and an activator and catalyst were added. The mixture was then refluxed under a protective gas atmosphere. The dried intermediate was dissolved in organic solvent 2, and a straight-chain haloalkane was added. The mixture was then reacted at 75-85°C for 12-24 h under a protective gas atmosphere. After drying and recrystallization, the quaternary ammonium salt containing the aromatic ester was obtained.
[0053] It should be noted that, in this invention, the completion of the reflux reaction is indicated when there is no more water in the water distributor.
[0054] Preferably, the base oil comprises any one or a combination of at least two of the following: trimethylolpropane oleate (TMPTO), trimethylolpropane arachidate, trimethylolpropane erucic acid ester, trimethylolpropane cocoate, trimethylolpropane lauryl ester, pentaerythritol oleate, tripentaerythritol lauryl ester, palm oil, or coconut oil.
[0055] Preferably, the extreme pressure agent comprises any one or a combination of at least two of phosphate esters, phosphates, sulfurized olefins, sulfurized esters or alkyl polysulfides, and more preferably any one or a combination of at least two of ammonium phosphate esters, oleyl phosphate esters, alkylamine phosphates, methyl sulfide or diisobutylene pentasulfide.
[0056] Preferably, the antioxidant includes phenolic antioxidants and / or amine antioxidants.
[0057] It should be noted that the present invention does not impose any special limitations on the specific selection of phenolic antioxidants and amine antioxidants. Commonly used phenolic antioxidants and amine antioxidants in the art are applicable. The phenolic antioxidants include, but are not limited to, 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butyl-4-(dimethylaminomethyl)phenol, and 2,6-diisobutyl-p-cresol. The amine antioxidants include, but are not limited to, p-diphenylamine, alkyldiphenylamine, and octyl / butyldiphenylamine antioxidants.
[0058] Preferably, the cationic surfactant comprises any one or a combination of at least two of the following: tallow amine polyethylene ether, N-tallow alkyl trimethylene diamine ethoxylate, or coconut oil amine ether.
[0059] Preferably, the long-term stable cationic rolling solution further includes a rust inhibitor.
[0060] Preferably, the rust inhibitor in the long-term stable cationic rolling solution is 0.5-1.0 parts by weight, for example, 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, 0.8 parts, 0.85 parts, 0.9 parts, 0.95 parts, or 1.0 parts, as well as specific values between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values included in the range.
[0061] Preferably, the rust inhibitor includes azole rust inhibitors, and more preferably benzotriazole and / or methylbenzotriazole.
[0062] In a second aspect, the present invention provides a method for preparing a long-term stable cationic rolling solution as described in the first aspect, the method comprising the following steps: The long-term stable cationic rolling solution is obtained by mixing base oil, extreme pressure agent, antioxidant, cationic surfactant and quaternary ammonium salt containing aromatic ester.
[0063] It should be noted that, in order to facilitate uniform mixing of the entire system, the rust inhibitor and a small amount of base oil can be stirred and heated to dissolve at a temperature of 75-85℃ (e.g., 75℃, 76℃, 77℃, 78℃, 79℃, 80℃, 81℃, 82℃, 83℃, 84℃, 85℃, 86℃, 87℃, 88℃, 89℃, or 90℃, etc.). After mixing until clear, the remaining base oil is added. After the system temperature cools to 45-55℃ (e.g., 45℃, 46℃, 47℃, 48℃, 49℃, 50℃, 51℃, 52℃, 53℃, 54℃, or 55℃, etc.), other raw material components are added and mixed until clear. Meanwhile, there are no special limitations on the cooling method, which includes, but is not limited to, natural cooling.
[0064] For example, the preparation method of the long-term stable cationic rolling solution provided by the present invention specifically includes the following steps: After mixing the optional rust inhibitor with a portion of the base oil at 75-85°C, the remaining base oil is added. The mixture is then cooled to 45-55°C, and extreme pressure agent, antioxidant, cationic surfactant, and quaternary ammonium salt containing aromatic ester are added. After mixing, the long-term stable cationic rolling fluid is obtained.
[0065] It should be noted that the base oil in this invention is only used to fully mix the rust inhibitor to obtain a uniform and transparent solution. There is no special limitation on the amount added, and the sum of the weight parts of the base oil and the remaining base oil is 80-95 parts.
[0066] Thirdly, the present invention provides an application of the long-term stable cationic rolling solution as described in the first aspect in the cold rolling process.
[0067] Compared with the prior art, the present invention has at least the following beneficial effects: (1) The present invention introduces quaternary ammonium salt containing aromatic esters into cationic rolling fluid. By combining it with cationic surfactants, it can more effectively protect the cationic surfactants in the cationic rolling fluid from failure, solve the problem of system collapse after long-term use of cationic rolling fluid on site. Moreover, the addition of quaternary ammonium salt containing aromatic esters will not have any negative impact on the original emulsion system, but will increase antibacterial and anti-rust properties, and further extend service life.
[0068] (2) The long-term stable cationic rolling fluid provided by the present invention has excellent comprehensive properties such as aging resistance (emulsion stability is 2.0-2.8%), rust prevention (corrosion area is 8-25%), lubrication (average film thickness is 54-68 nm) and antibacterial properties (bacterial growth area is 10-20%). Detailed Implementation
[0069] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.
[0070] Unless otherwise specified, the materials and equipment involved in the following detailed embodiments are all conventional materials and equipment in the art and will not affect the technical effects of the present invention.
[0071] Unless otherwise specified, all reagents and raw materials used in the following examples and comparative examples are commercially available products. Some raw material information is shown in the table below: Preparation Example 1 This preparation example provides a hydroxyethyl tetradecyl quaternary ammonium salicylate, which is prepared by the following method, which includes the following steps: In a dry three-necked flask, salicylic acid (1.0 equiv.), N,N-dimethylethanolamine (1.1 equiv.), and toluene (5 equiv.) were added and mixed. Then, dicyclohexylcarbodiimide (1.08 equiv.) and 4-dimethylaminopyridine (0.15 equiv.) were added. The mixture was refluxed at 110°C under nitrogen protection until no water was found in the separator, at which point the reaction was stopped. The resulting salicylate tertiary amine intermediate, obtained after vacuum concentration, was dissolved in acetonitrile (5 equiv.), and 1-bromotetradecane (1.5 equiv.) was added. The mixture was stirred at 80°C for 18 h under nitrogen protection. After the reaction was completed, the solvent was removed by vacuum distillation, and the product was recrystallized from the ethyl acetate / ethanol mixture to obtain the hydroxyethyltetradecyl quaternary ammonium salicylate.
[0072] The 1H NMR characterization data of the salicylic acid hydroxyethyltetradecyl quaternary ammonium salt are shown below: 1 H NMR(400 MHz, CDCl3): σ15.31-15.26(s, 1H), 7.84-7.79(s, 1H), 7.47-7.42(s, 1H), 7.02-6.86(s, 2H), 4.72-4.65(m, 2H), 3.72-3.66(m, 2H), 3.33-3.18(m, 8H), 1.66(m, 2H), 1.31-1.25(m, 25H).
[0073] Preparation Example 2 This preparation example provides a hydroxyethyl dodecyl quaternary ammonium salicylate, which is prepared by the following method, which includes the following steps: In a dry three-necked flask, salicylic acid (1.0 equiv.), N,N-dimethylethanolamine (1.05 equiv.), and toluene (5 equiv.) were added and mixed. Then, dicyclohexylcarbodiimide (1.05 equiv.) and 4-dimethylaminopyridine (0.2 equiv.) were added. The mixture was refluxed at 110°C under nitrogen protection until no water was found in the separator, at which point the reaction was stopped. The resulting salicylate tertiary amine intermediate obtained after vacuum concentration was dissolved in acetonitrile (5 equiv.), and 1-bromododecane (1.3 equiv.) was added. The mixture was stirred at 75°C for 24 h under nitrogen protection. After the reaction was completed, the solvent was removed by vacuum distillation, and the product was recrystallized from the ethyl acetate / ethanol mixture to obtain the hydroxyethyldodecyl quaternary ammonium salicylate.
[0074] Preparation Example 3 This preparation example provides a hydroxyethyl octadecyl quaternary ammonium salicylate salt, which is prepared by the following method, which includes the following steps: In a dry three-necked flask, salicylic acid (1.0 equiv.), N,N-dimethylethanolamine (1.3 equiv.), and toluene (5 equiv.) were added and mixed. Then, dicyclohexylcarbodiimide (1.10 equiv.) and 4-dimethylaminopyridine (0.1 equiv.) were added. The mixture was refluxed at 110°C under nitrogen protection until no water was found in the separator, at which point the reaction was stopped. The resulting salicylate tertiary amine intermediate, obtained after vacuum concentration, was dissolved in acetonitrile (5 equiv.), and 1-bromooctadecane (1.7 equiv.) was added. The mixture was stirred at 85°C for 12 h under nitrogen protection. After the reaction was completed, the solvent was removed by vacuum distillation, and the product was recrystallized from the ethyl acetate / ethanol mixture to obtain the hydroxyethylhexadecyl quaternary ammonium salicylate.
[0075] Preparation Example 4 This preparation example provides a hydroxyethyl decaalkyl quaternary ammonium salicylate, which differs from Preparation Example 1 only in that 1-bromotetradecane is replaced with an equimolar amount of 1-bromodecane. All other raw materials, contents and preparation methods are the same as in Preparation Example 1.
[0076] Preparation Example 5 This preparation example provides a hydroxyethyl eicosyl quaternary ammonium salt of salicylate, which differs from Preparation Example 1 only in that 1-bromotetradecane is replaced with an equimolar amount of 1-bromoeicosyl, while the other raw materials, contents and preparation methods are the same as those in Preparation Example 1.
[0077] Example 1 This embodiment provides a long-term stable cationic rolling solution and its preparation method. The long-term stable cationic rolling solution comprises the following components in parts by weight: 91.5 parts palm oil; 5.0 parts of oleyl phosphate; Octyl / butyl diphenylamine liquid antioxidant 1.0 part; 2.0 parts of tallow amine polyethylene ether; Hydroxyethyltetradecyl quaternary ammonium salicylate (Preparation Example 1) 0.2 parts; Benzotriazole 0.5 parts.
[0078] The preparation method of the long-term stable cationic rolling solution includes the following steps: Benzotriazole was mixed with a portion of palm oil at 80°C until clarified. The remaining portion of palm oil was added, and the mixture was cooled to 50°C. Oleyl phosphate, octyl / butyl diphenylamine liquid antioxidant, tallow amine polyethylene ether, and hydroxyethyl tetradecyl quaternary ammonium salicylate (Preparation Example 1) were added. After mixing until clarified, the long-term stable cationic rolling solution was obtained.
[0079] Example 2 This embodiment provides a long-term stable cationic rolling solution and its preparation method. The long-term stable cationic rolling solution comprises the following components in parts by weight: 94.8 parts of coconut oil; Alkylamine phosphate 1.0 part; 0.8 parts of 2,6-diisobutyl-p-cresol; 0.5 parts of N-tartrate alkyl trimethylene diamine ethoxylate; Hydroxyethyl dodecyl quaternary ammonium salicylate (Preparation Example 2) 0.1 parts; 0.8 parts of methylbenzotriazole.
[0080] The preparation method of the long-term stable cationic rolling solution includes the following steps: Methylbenzotriazole was mixed with a portion of coconut oil at 75°C until clarified. The remaining portion of coconut oil was added, and the mixture was cooled to 45°C. Alkylamine phosphate, 2,6-diisobutyl-p-cresol, N-tartrate alkyltrimethylenediamine ethoxylate, and hydroxyethyl dodecyl salicylate quaternary ammonium salt (Preparation Example 2) were added and mixed until clarified to obtain the long-term stable cationic rolling solution.
[0081] Example 3 This embodiment provides a long-term stable cationic rolling solution and its preparation method. The long-term stable cationic rolling solution comprises the following components in parts by weight: Pentaerythritol oleate 85.2 parts; 2.5 parts of sulfurized fatty acid methyl ester; 0.5 parts of octyl / butyl diphenylamine liquid antioxidant; 1.0 part of coconut oil-based amino ether; Hydroxyethyl octadecyl quaternary ammonium salicylate (Preparation Example 3) 0.8 parts; Benzotriazole 1.0 part.
[0082] The preparation method of the long-term stable cationic rolling solution includes the following steps: Benzotriazole and a portion of pentaerythritol oleate were mixed at 85°C until clear. The remaining portion of pentaerythritol oleate was added, and the mixture was cooled to 55°C. Sulfated fatty acid methyl ester, octyl / butyl diphenylamine liquid antioxidant, coconut oil-based amine ether, and hydroxyethyl octadecyl salicylate quaternary ammonium salt (Preparation Example 3) were added and mixed until clear to obtain the long-term stable cationic rolling solution.
[0083] Example 4 This embodiment provides a long-term stable cationic rolling fluid and its preparation method. The only difference between this embodiment and Example 1 is that the weight of hydroxyethyl tetradecyl quaternary ammonium salicylate (Preparation Example 1) is adjusted from 0.2 parts to 0.1 parts, and the reduced weight is allocated to base oil 1. The other components, weights, and preparation methods are the same as in Example 1.
[0084] Example 5 This embodiment provides a long-term stable cationic rolling fluid and its preparation method. The only difference between this embodiment and Example 1 is that the weight of the hydroxyethyl tetradecyl quaternary ammonium salicylate (Preparation Example 1) is adjusted from 0.2 parts to 0.4 parts, and the increased weight is achieved by reducing the weight of the base oil 1 accordingly. All other components, weights, and preparation methods are the same as in Example 1.
[0085] Example 6 This embodiment provides a long-term stable cationic rolling fluid and its preparation method. The only difference between this embodiment and Example 1 is that the weight of the hydroxyethyl tetradecyl quaternary ammonium salicylate (Preparation Example 1) is adjusted from 0.2 parts to 1 part, and the increase in weight is achieved by reducing the weight of the base oil 1 accordingly. All other components, weights, and preparation methods are the same as in Example 1.
[0086] Example 7 This embodiment provides a long-term stable cationic rolling solution and its preparation method. The only difference between this embodiment and Example 1 is that the hydroxyethyltetradecyl quaternary ammonium salt of salicylate (Preparation Example 1) is replaced with an equal weight proportion of hydroxyethyldodecyl quaternary ammonium salt of salicylate (Preparation Example 2). The other components, weight proportions and preparation methods are the same as in Example 1.
[0087] Example 8 This embodiment provides a long-term stable cationic rolling solution and its preparation method. The only difference between this embodiment and Example 1 is that the hydroxyethyl tetradecyl quaternary ammonium salt of salicylate (Preparation Example 1) is replaced with an equal weight proportion of hydroxyethyl octadecyl quaternary ammonium salt of salicylate (Preparation Example 3). The other components, weight proportions and preparation methods are the same as in Example 1.
[0088] Example 9 This embodiment provides a long-term stable cationic rolling solution and its preparation method. The only difference between this embodiment and Example 1 is that the hydroxyethyl tetradecyl quaternary ammonium salt of salicylate (Preparation Example 1) is replaced with an equal weight proportion of hydroxyethyl decadecyl quaternary ammonium salt of salicylate (Preparation Example 4). The other components, weight proportions and preparation methods are the same as in Example 1.
[0089] Example 10 This embodiment provides a long-term stable cationic rolling solution and its preparation method. The only difference between this embodiment and Example 1 is that the hydroxyethyl tetradecyl quaternary ammonium salt of salicylate (Preparation Example 1) is replaced with an equal weight proportion of hydroxyethyl eicosyl quaternary ammonium salt of salicylate (Preparation Example 5). The other components, weight proportions and preparation methods are the same as in Example 1.
[0090] Comparative Example 1 This comparative example provides a long-term stable cationic rolling fluid and its preparation method. The only difference between this and Example 1 is that the weight of the hydroxyethyl tetradecyl quaternary ammonium salicylate (Preparation Example 1) is adjusted from 0.2 parts to 1.2 parts, and the increased weight is achieved by reducing the weight of the base oil 1 accordingly. All other components, weights, and preparation methods are the same as in Example 1.
[0091] Comparative Example 2 This comparative example provides a cationic rolling solution and its preparation method. The only difference between this solution and Example 1 is that the hydroxyethyltetradecyl quaternary ammonium salt of salicylate (Preparation Example 1) is not added, and its reduced weight parts are allocated to palm oil. The other components, weight parts, and preparation methods are the same as in Example 1.
[0092] Comparative Example 3 This comparative example provides a cationic rolling solution and its preparation method. The only difference between this solution and Example 1 is that the salicylic acid hydroxyethyl tetradecyl quaternary ammonium salt (Preparation Example 1) is replaced with an equal weight proportion of diester mono-tailed cationic surfactant (prepared according to Example 15 of CN119490426A). The other components, weight proportions and preparation methods are the same as in Example 1.
[0093] The cationic rolling solutions provided in Examples 1-10 and Comparative Examples 1-3 were subjected to performance tests, and the test methods / standards are as follows: (1) Stability of the aged emulsion The cationic rolling solution was prepared into an emulsion with a mass concentration of 3% using deionized water. The emulsion was poured into a beaker and air was continuously introduced. The solution was heated and stirred at 55°C for 72 h. 2.5 mL of the solution was then taken out and tested for concentration in a wet balance.
[0094] (2) Rust prevention performance test (stacked test): The cationic rolling solution was prepared into a 3% (w / w) emulsion using deionized water. Two steel sheets of the same area were prepared for each product and polished to a fresh surface under the same conditions. 2 mL of the emulsion was then dropped onto one of the steel sheets. The two sheets were then stacked together, with the emulsion evenly sandwiched between them. The steel sheets were sealed, a 5 kg weight was placed on top, and the sheets were placed in a 90℃ oven for 72 hours. Afterward, the sheets were removed, the corrosion area was observed, and the percentage of corrosion on the steel sheet area was calculated.
[0095] (3) Lubrication performance test (evaluated by PCS Interferometer): The film-forming ability of the rolling fluid between friction pairs was evaluated using oil film thickness (nm) as the scale. The specific test method was as follows: the cationic rolling fluid was prepared into an emulsion with a mass concentration of 3% by water and then placed into the test chamber. Under certain conditions (50℃, load 20 N), the test ball and the test disk moved relative to each other and gradually increased in speed (0-6 m / s). A total of 68 data points were tested, and the average film thickness of 30 data points was recorded as the average film thickness.
[0096] (4) Antibacterial performance test: Prepare a 3% emulsion of cationic rolling solution with water. Take 2 mL and spread it onto a test strip (purchased from Shumei, mikrocount duo test strip). Place the test strip in a 30℃ oven for 72 h and then observe the number of colonies on the test strip (judged by the percentage of the area with bacteria on the test strip).
[0097] The test results are shown in Table 1.
[0098] Table 1 According to the test results in Table 1: (1) As can be seen from Examples 1 to 10, the present invention introduces quaternary ammonium salt containing aromatic esters into cationic rolling fluid, which can more effectively protect the cationic surfactant in the cationic rolling fluid from failure, thereby making the obtained long-term stable cationic rolling fluid have excellent comprehensive properties such as aging resistance (emulsion stability of 2.0-2.8%), rust prevention (corrosion area of 8-25%), lubrication (average film thickness of 54-68 nm) and antibacterial properties (bacterial growth area of 10-20%).
[0099] (2) By comparing Example 1 with Examples 4-6 and Comparative Example 1, it can be seen that the content of quaternary ammonium salt containing aromatic esters in Example 4 is relatively low, resulting in a lower mass ratio between the quaternary ammonium salt and the cationic surfactant. As a result, the emulsion stability and average film thickness of the obtained long-term stable cationic rolling fluid are significantly reduced, while the corrosion area and bacterial growth area are increased. In Comparative Example 1, the content of quaternary ammonium salt containing aromatic esters is relatively high, resulting in a higher mass ratio between the quaternary ammonium salt and the cationic surfactant. This leads to an excessively strong emulsification effect of the bait molecules in the system. Although this increases the emulsion stability of the cationic rolling fluid, the excessive emulsification results in a significant reduction in the average film thickness, which is very detrimental to lubrication. At the same time, the corrosion area and bacterial growth area of the obtained cationic rolling fluid are increased. This indicates that by adjusting the content of quaternary ammonium salt containing aromatic esters, the present invention can further regulate the mass ratio between the quaternary ammonium salt and the cationic surfactant, thereby improving the aging resistance, rust prevention, lubrication, and antibacterial properties of the obtained long-term stable cationic rolling fluid.
[0100] (3) By comparing Example 1 with Examples 7-10, it can be seen that the hydrophobic carbon chain of the quaternary ammonium salt containing aromatic ester in Example 9 is shorter, and the emulsion stability and average film thickness of the long-term stable cationic rolling solution obtained therefrom are reduced, while the bacterial growth area is increased. In Example 10, the hydrophobic carbon chain of the quaternary ammonium salt containing aromatic ester is longer, and the emulsion stability of the long-term stable cationic rolling solution obtained therefrom is reduced, while the corrosion area is increased. This shows that by optimizing the length of the hydrophobic carbon chain of the quaternary ammonium salt containing aromatic ester, the present invention can improve the comprehensive performance of the long-term stable cationic rolling solution, such as aging resistance, rust prevention, lubrication and antibacterial properties, in just one step.
[0101] (4) By comparing Examples 1-10 with Comparative Examples 2 and 3, it can be seen that when no additional quaternary ammonium salt is added (Comparative Example 2) or when a non-specific aromatic ester-containing quaternary ammonium salt is added (Comparative Example 3), the overall performance of the cationic rolling solution, such as aging resistance, rust prevention, lubrication and antibacterial properties, deteriorates.
[0102] In summary, this invention, by introducing quaternary ammonium salts containing aromatic esters into cationic rolling fluids, can more effectively protect against the failure of cationic surfactants in the cationic rolling fluids, solving the problem of system collapse after long-term use of cationic rolling fluids in the field. Furthermore, the addition of quaternary ammonium salts containing aromatic esters not only does not have any negative impact on the original emulsion system, but also increases antibacterial and anti-rust properties, further extending service life. Moreover, by optimizing the content and structure of the quaternary ammonium salts containing aromatic esters, the resulting long-term stable cationic rolling fluid can be further improved in terms of aging resistance (emulsion stability of 2.2-2.8%), anti-rust properties (corrosion area of 8-15%), lubrication properties (average film thickness of 59-68 nm), and antibacterial properties (bacterial growth area of 10-15%), among other comprehensive properties.
[0103] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.
Claims
1. A long-term stable cationic rolling solution, characterized in that, The long-term stable cationic rolling solution comprises the following components in parts by weight: 80-95 parts base oil; Extreme pressure agent 1.0-5.0 parts; Antioxidant 0.5-1.0 parts; 0.5-2.0 parts of cationic surfactant; 0.1-1.0 parts of quaternary ammonium salt containing aromatic esters.
2. The long-term stable cationic rolling solution according to claim 1, characterized in that, The mass ratio of the aromatic ester-containing quaternary ammonium salt to the cationic surfactant is (0.1-0.5):
1.
3. The long-term stable cationic rolling solution according to claim 1 or 2, characterized in that, The aromatic ester-containing quaternary ammonium salt has the following structure: ； Where n is an integer selected from 11 to 17; Preferably, the aromatic ester-containing quaternary ammonium salt is prepared by a first-stage reaction of hydroxybenzoic acid and N,N-dimethylethanolamine, followed by a second-stage reaction with a straight-chain haloalkane. Preferably, the molar ratio of hydroxybenzoic acid to N,N-dimethylethanolamine is 1:(1-1.3); Preferably, the first stage reaction is carried out under an activating agent; Preferably, the molar ratio of the activator to hydroxybenzoic acid is (1.05-1.10):1; Preferably, the activator comprises dicyclohexylcarbodiimide. Preferably, the first stage reaction is carried out under a catalyst; Preferably, the molar ratio of the catalyst to hydroxybenzoic acid is (0.1-0.2):1; Preferably, the catalyst comprises 4-dimethylaminopyridine; Preferably, the first stage reaction is carried out in an organic solvent 1, which includes toluene; Preferably, the first stage reaction is carried out under reflux; Preferably, the molar ratio of the straight-chain haloalkane to hydroxybenzoic acid is (1.3-1.7):1; Preferably, the straight-chain alkyl haloalkane comprises C12-C18 straight-chain alkyl haloalkane; Preferably, the second stage reaction is carried out in an organic solvent 2, which includes acetonitrile; Preferably, the temperature of the second stage reaction is 75-85℃, and the time is 12-24 h; Preferably, both the first-stage reaction and the second-stage reaction are carried out in a protective gas atmosphere, wherein the protective gas includes any one or a combination of at least two of nitrogen, argon or helium; Preferably, the second stage reaction further includes a post-processing step; Preferably, the post-processing method includes drying and recrystallization; Preferably, the drying method includes vacuum distillation; Preferably, the recrystallization is carried out in a recrystallization solvent, which includes ethyl acetate and ethanol.
4. The long-term stable cationic rolling solution according to any one of claims 1-3, characterized in that, The base oil includes any one or a combination of at least two of the following: trimethylolpropane oleate, trimethylolpropane arachidate, trimethylolpropane erucic acid ester, trimethylolpropane cocoate, trimethylolpropane lauryl ester, pentaerythritol oleate, tripentaerythritol lauryl ester, palm oil, or coconut oil.
5. The long-term stable cationic rolling solution according to any one of claims 1-4, characterized in that, The extreme pressure agent includes any one or a combination of at least two of phosphate esters, phosphates, sulfurized olefins, sulfurized esters or alkyl polysulfides, preferably any one or a combination of at least two of ammonium phosphate esters, oleyl phosphate esters, alkylamine phosphates, methyl sulfide or diisobutylene pentasulfide.
6. The long-term stable cationic rolling solution according to any one of claims 1-5, characterized in that, The antioxidants include phenolic antioxidants and / or amine antioxidants.
7. The long-term stable cationic rolling solution according to any one of claims 1-6, characterized in that, The cationic surfactant includes any one or a combination of at least two of the following: tallow amine polyethylene ether, N-tallow alkyl trimethylene diamine ethoxylate, or coconut oil amine ether.
8. The long-term stable cationic rolling solution according to any one of claims 1-7, characterized in that, The long-term stable cationic rolling fluid also includes a rust inhibitor; Preferably, the rust inhibitor in the long-term stable cationic rolling solution is 0.5-1.0 parts by weight; Preferably, the rust inhibitor includes azole rust inhibitors, more preferably benzotriazole and / or methylbenzotriazole.
9. A method for preparing a long-term stable cationic rolling solution as described in any one of claims 1-8, characterized in that, The preparation method includes the following steps: The long-term stable cationic rolling solution is obtained by mixing base oil, extreme pressure agent, antioxidant, cationic surfactant and quaternary ammonium salt containing aromatic ester.
10. The application of a long-term stable cationic rolling fluid as described in any one of claims 1-8 in a cold rolling process.