Corrosion inhibitor composition as well as preparation method and application thereof

Abstract

The invention discloses a corrosion inhibitor composition. The corrosion inhibitor composition comprises a compound shown in a formula I and an anti-rust agent. The corrosion inhibitor composition has excellent oil solubility, can be used for preparing anti-rust oil in lubricating oil and lubricating grease, and has general applicability. The corrosion inhibitor composition can obviously improve the oxidation resistance of anti-rust oil, improves the function of inhibiting copper corrosion, and also has an effect of improving the anti-rust performance.

Description

Technical Field

[0001] This invention belongs to the field of lubricating oil technology, specifically relating to a corrosion inhibitor composition, its preparation method, and its application. Background Technology

[0002] Corrosion inhibitors are one type of lubricating oil additive, characterized by their ability to effectively enhance the lubricating oil's ability to inhibit metal corrosion despite requiring only a small dosage. Corrosion inhibitors can be broadly classified into inorganic and organic corrosion inhibitors. Organic corrosion inhibitors can acquire free electrons from the metal surface by forming back bonds with antibonding orbitals during chemical reactions, or they can contribute electrons to vacant d orbitals on the metal surface or adsorption sites on the oxide layer surface, forming coordinate covalent bonds and thus creating a stable adsorption film on the metal surface to protect it from corrosive media.

[0003] Currently, corrosion inhibitors widely used in the lubricating oil field include triazole derivatives (T551), methyltriazole derivatives (T571), thiadiazole derivatives (T561), and 1,2,4-triazole derivatives (T553), etc. However, their oil solubility in different types of base oils and their performance in inhibiting metal corrosion need further improvement. Environmental protection and sustainable development are eternal themes of human development, and "green chemistry" has become the main line of chemical development. For "green chemistry," the advantages of low melting point, low toxicity, low vapor pressure, excellent thermal stability, and environmental friendliness have become a new trend in the development and application of additives. There are many patents related to corrosion inhibitors. For example, CN 114686890A discloses a novel oil-soluble corrosion inhibitor, which is mainly composed of polyamine components such as quaternary ammonium salts, tallow amine, hexadecylamine, and octadecylamine, combined with other concentrated additives. It exhibits excellent copper corrosion inhibition function, but its preparation method is too complex and involves many raw materials, making it unsuitable for general application in lubricant formulation development. CN115043822A discloses a benzotriazole derivative corrosion inhibitor, which exhibits excellent water solubility and metal corrosion inhibition function, but it lacks solubility in lubricant base oils and cannot be applied. CN115335495A discloses a composite corrosion inhibitor, which includes alkali metals or alkaline earth metals. In addition to being ineffective in inhibiting copper corrosion, it may even accelerate copper corrosion, making it unsuitable for general application. Currently, a large amount of research focuses on corrosion inhibitors used in aqueous solutions, while research on corrosion inhibitors used in lubricating oils is relatively limited, especially research on high-performance oil-soluble benzotriazole derivative corrosion inhibitors.

[0004] Rust-preventive oils are a special type of lubricant whose primary function is to protect mechanical parts from corrosion by corrosive media (such as water and halide ions). With the rapid development of China's industry, the use of rust-preventive oils in the machinery manufacturing industry is constantly increasing, and the improvement of their performance has received more attention. Traditional rust-preventive oils mostly provide excellent rust prevention for steel machinery or parts, and the rust inhibitors are mostly carboxylic acid derivatives. Excessive addition of carboxylic acid derivatives can cause severe corrosion to copper materials on machinery. Therefore, developing additives and rust-preventive oils that inhibit corrosion of both steel and copper has become a key focus for researchers in this field. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention provides a benzotriazole derivative corrosion inhibitor composition for use with rust-preventive oils, and particularly relates to an additive suitable for use as an inhibitor of copper corrosion in lubricating oils, exhibiting excellent effects in rust-preventive oils.

[0006] A first aspect of the present invention provides a corrosion inhibitor composition comprising:

[0007] Formula I compound

[0008]

[0009] Rust inhibitor;

[0010] Among them, R1, R2, R3, and R4 may be the same as or different from each other, and each is independently selected from hydrogen, C 1-20 A straight-chain or branched hydrocarbon group, and at least one of R2 and R3 is not hydrogen;

[0011] R5, R6, and R7 are each independently selected from C. 1-20 Straight-chain or branched hydrocarbon groups.

[0012] According to the corrosion inhibitor composition of the first aspect, the rust inhibitor is selected from one or more of dodecenylsuccinic acid and heptadecanylimidazolinylsuccinate; and / or

[0013] R1 is selected from C 1-20 Branched alkyl groups;

[0014] Preferably, the mass ratio of the compound of formula I to the rust inhibitor is (3-1):1, more preferably (1-2.5):1.

[0015] According to the corrosion inhibitor composition of the first aspect, the corrosion inhibitor composition further includes at least one of extreme pressure anti-wear agent, antioxidant, and antifoaming agent;

[0016] Preferably, the extreme pressure anti-wear agent is selected from one or more of tricresyl phosphate, sulfur-phosphorus nitrogen-containing derivatives, and mixtures of acidic phosphate amine salts, and is preferably tricresyl phosphate;

[0017] Preferably, the antioxidant is selected from one or more of N-phenyl-α-naphthylamine, 2,6-di-tert-butyl-p-cresol, and alkyl diphenylamine, and more preferably N-phenyl-α-naphthylamine and / or 2,6-di-tert-butyl-p-cresol; and / or

[0018] Preferably, the antifoaming agent is selected from one or more of methyl silicone oil, amine and ethylene oxide condensate, and is preferably methyl silicone oil.

[0019] The method for preparing the corrosion inhibitor composition of the first aspect includes:

[0020] (1) Compound II is reacted with a tertiary carbon amine in a solvent to prepare compound I, the structure of which is:

[0021]

[0022] Among them, R1, R2, R3, and R4 may be the same as or different from each other, and each is independently selected from hydrogen, C 1-20 A straight-chain or branched hydrocarbon group, and at least one of R2 and R3 is not hydrogen;

[0023] (2) The compound of formula I prepared in step (1) is mixed with a rust inhibitor to obtain the corrosion inhibitor composition.

[0024] According to the method of the second aspect, in step (1), the tertiary primary amine is selected from C 12-14 One or more of tertiary alkylamines and dodecyl-dimethylamines; and / or

[0025] The solvent is a protic solvent, preferably one or more of methanol, ethanol, and water.

[0026] According to the method of the second aspect, in step (1), the molar ratio of the compound of formula II to the tertiary carbon primary amine is 1:1 to 1.5, preferably 1:1 to 1.3.

[0027] According to the method of the second aspect, in step (1), after the compound of formula II and the tertiary carbon primary amine are added to the solvent, they are first heated and stirred at a first temperature, and then heated and refluxed at a second temperature.

[0028] According to the method of the second aspect, the first temperature is 45℃~55℃;

[0029] The heating and stirring time is 1 hour to 1.5 hours;

[0030] The second temperature is 75℃~100℃, preferably 75℃~90℃; and / or

[0031] The heating reflux time is 3 to 12 hours, preferably 4 to 8 hours.

[0032] According to the method of the second aspect, step (1) further includes: purifying the obtained compound of formula I;

[0033] Preferably, the purification method is selected from one or more of the following: washing, distillation, filtration, drying, and recrystallization.

[0034] A third aspect of the present invention provides a lubricating oil comprising:

[0035] The corrosion inhibitor composition of the first aspect or the corrosion inhibitor composition prepared according to the method of the second aspect.

[0036] The corrosion inhibitor composition of the present invention has, but is not limited to, the following beneficial effects:

[0037] The corrosion inhibitor composition of the present invention has excellent oil solubility and can be used in the preparation of rust-preventive oils in lubricating oils and greases, thus having broad applicability. The corrosion inhibitor composition of the present invention can significantly improve the antioxidant properties of rust-preventive oils, enhance the function of inhibiting copper corrosion, and also improve rust prevention performance. Attached Figure Description

[0038] Figure 1 The infrared spectrum of product A prepared in Example 1 is shown. Detailed Implementation

[0039] The present application will be further described in detail below through embodiments. Through these descriptions, the features and advantages of the present application will become clearer and more apparent.

[0040] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0041] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0042] This invention provides a corrosion inhibitor composition comprising:

[0043] Formula I compound

[0044]

[0045] Rust inhibitor;

[0046] in,

[0047] R1, R2, R3, and R4 may be the same as or different from each other, and each is independently selected from hydrogen, C, and C. 1-20 A straight-chain or branched hydrocarbon group, and at least one of R2 and R3 is not hydrogen;

[0048] R5, R6, and R7 are each independently selected from C. 1-20 Straight-chain or branched hydrocarbon groups.

[0049] In one specific embodiment, at least one of R2 and R3 can be C. 1-4 Hydrocarbon group.

[0050] In one embodiment, the rust inhibitor is selected from one or more of dodecenylsuccinic acid and heptadecanylimidazolinylsuccinate, preferably dodecenylsuccinic acid; and / or

[0051] R1 is selected from C 1-20 Branched alkyl groups.

[0052] In one embodiment, the mass ratio of the compound of formula I to the rust inhibitor is (3-1):1, preferably (1-2.5):1.

[0053] In one embodiment, the corrosion inhibitor composition further includes at least one of extreme pressure anti-wear agent, antioxidant, and antifoaming agent;

[0054] Preferably, the extreme pressure anti-wear agent is selected from one or more of tricresyl phosphate T306, nitrogen-containing derivative of thiophosphate T305, and acidic phosphate amine salt T349, and is preferably tricresyl phosphate T306.

[0055] Preferably, the antioxidant is selected from one or more of N-phenyl-α-naphthylamine T531, 2,6-di-tert-butyl-p-cresol T501, and alkyl diphenylamine T534, preferably N-phenyl-α-naphthylamine T531 and / or 2,6-di-tert-butyl-p-cresol T501; and / or

[0056] Preferably, the antifoaming agent is selected from one or more of methyl silicone oil T901 and amine-ethylene oxide condensate T1001, and is preferably methyl silicone oil T901.

[0057] The present invention also provides a method for preparing the corrosion inhibitor composition, comprising:

[0058] (1) Compound II is reacted with a tertiary carbon amine in a solvent to prepare compound I, the structure of which is:

[0059]

[0060] in,

[0061] R1, R2, R3, and R4 may be the same as or different from each other, and each is independently selected from hydrogen, C, and C. 1-20 A straight-chain or branched hydrocarbon group, and at least one of R2 and R3 is not hydrogen;

[0062] (2) The compound of formula I prepared in step (1) is mixed with a rust inhibitor to obtain the corrosion inhibitor composition.

[0063] In one specific embodiment, at least one of R2 and R3 can be C. 1-4 Hydrocarbon group.

[0064] In one embodiment, in step (1), the tertiary primary amine is selected from C 12-14 One or more of the tertiary alkylamines PRIMENE 81-R and dodecyl-dimethyl primary amines; and / or

[0065] The solvent is a protic solvent, preferably one or more of methanol, ethanol, and water.

[0066] In one embodiment, in step (1), the molar ratio of the compound of formula II to the tertiary carbon primary amine is 1:1 to 1.5, preferably 1:1 to 1.3.

[0067] In one embodiment, in step (1), after the compound of formula II and the tertiary carbon primary amine are added to the solvent, they are first heated and stirred at a first temperature, and then heated and refluxed at a second temperature.

[0068] In one embodiment, the first temperature is 45°C to 55°C;

[0069] The heating and stirring time is 1 hour to 1.5 hours;

[0070] The second temperature is 75℃~100℃, preferably 75℃~90℃; and / or

[0071] The heating reflux time is 3 to 12 hours, preferably 4 to 8 hours.

[0072] In one embodiment, step (1) further includes: purifying the obtained compound of formula I.

[0073] Preferably, the purification method is selected from one or more of the following: washing, distillation, filtration, drying, and recrystallization.

[0074] The present invention also provides a lubricating oil comprising the corrosion inhibitor composition described above.

[0075] This invention does not impose any special restrictions on the source of any raw materials; unless otherwise specified, they are all conventional products that can be obtained commercially.

[0076] The present invention will be further described below with reference to embodiments, but these do not constitute a limitation thereof. The raw materials used are as follows:

[0077] C 12-14 Tertiary primary amines, industrial code: PRIMENE 81-R, Shanghai Wujing Chemical Technology Co., Ltd., industrial products.

[0078] 5-Butylbenzyltriazole, 5-methylbenzyltriazole, Sinopharm Chemical Reagent Co., Ltd.; anhydrous ethanol, Sinopharm Chemical Reagent Co., Ltd.; analytical grade.

[0079] Petroleum ether, Sinopharm Chemical Reagent Co., Ltd., analytical grade

[0080] Corrosion inhibitor N,N'-dialkylaminomethylenetriazole, industrial code: T551, Changsha Wangcheng Petrochemical Co., Ltd., industrial product.

[0081] Corrosion inhibitor thiadiazole derivative, industrial code T561, Changsha Wangcheng Petrochemical Co., Ltd., industrial product.

[0082] Corrosion inhibitor methyltriazole derivative, industrial code: T571, Changsha Wangcheng Petrochemical Co., Ltd., industrial product.

[0083] Antioxidant N-phenyl-α-naphthylamine, industrial code: T531, Shanghai Demao Chemical Co., Ltd., industrial product.

[0084] Extreme pressure anti-wear agent tricresyl phosphate, industrial code: T306, Zibo Huihua Co., Ltd., industrial product.

[0085] Antioxidant 2,6-di-tert-butyl-p-cresol, industrial code: T501, Zibo Huihua Co., Ltd., industrial product.

[0086] Antifoaming agent methyl silicone oil, industrial code: T901, Zibo Huihua Co., Ltd., industrial product.

[0087] Rust inhibitor dodecenyl succinic acid, industrial code: T746;

[0088] Rust inhibitor heptadecanylimidazoline succinate, industrial code: T703, Shandong Nengju Chemical Co., Ltd., industrial product.

[0089] Base oil II+6, Sinopec Maoming Branch, industrial products

[0090] Example 1

[0091] 17.5 g of 5-butyltriazole, 20.4 g of tertiary carbon amine PRIMENE 81-R, and 50 ml of anhydrous ethanol were placed in a 250 ml three-necked reaction flask. Stirring and heating were initiated. After stirring at 50 °C for 30 min, the temperature was increased to 80 °C and refluxed for 5 h. After the reaction was complete, the mixture was cooled to room temperature, filtered, and then rotary evaporated to obtain product A, a deep yellow viscous liquid with a conversion rate of 90.5%. The infrared spectrum is attached. Figure 1 .

[0092] Product A and T746 were mixed at a mass ratio of 5:4 to obtain the corrosion inhibitor composition A of this embodiment.

[0093] Example 2

[0094] 13.4 g of 5-methyltriazole, 20.4 g of tertiary amine PRIMENE 81-R, and 50 ml of anhydrous ethanol were placed in a 250 ml three-necked reaction flask. Stirring and heating were initiated. The mixture was stirred at 50 °C for 30 min, then heated to 80 °C and refluxed for 5 h. After the reaction was complete, the mixture was cooled to room temperature, filtered, and then rotary evaporated to obtain product B, a deep yellow viscous liquid with a conversion rate of 91.8%.

[0095] Product B and T746 were mixed at a mass ratio of 5:4 to obtain the corrosion inhibitor composition B of this embodiment.

[0096] Example 3

[0097] 13.4 g of 5-methyltriazole, 20.4 g of tertiary amine PRIMENE 81-R, and 50 ml of anhydrous ethanol were placed in a 250 ml three-necked reaction flask. Stirring and heating were initiated. The mixture was stirred at 48 °C for 30 min, then heated to 78 °C and refluxed for 6 h. After the reaction was complete, the mixture was cooled to room temperature, filtered, and rotary evaporated to obtain product C, a deep yellow viscous liquid with a conversion rate of 90.3%.

[0098] Product C was mixed with T746 at a mass ratio of 5:4 to obtain the corrosion inhibitor composition C of this embodiment.

[0099] Example 4

[0100] Product B was prepared according to the method of Example 2. Product B was mixed with T746 at a mass ratio of 5:2 to obtain the corrosion inhibitor composition D of this example.

[0101] Example 5

[0102] Product A was prepared according to the method of Example 1. Product A was then mixed with T703 at a mass ratio of 5:4 to obtain the corrosion inhibitor combination E of this example.

[0103] Experimental Example 1

[0104] 0.01 mol of dodecanoic acid was added to 100 g of II+6 base oil as a base. 0.01 mol of T551, T561, T571, and the corrosion inhibitor compositions of Examples 1-4 were added to the base (the corrosion inhibitor compositions are based on the molar amount of product A, product B, or product C; for example, 0.01 mol of corrosion inhibitor composition A contains 0.01 mol of product A). Individual products A, B, C, and T746 were used as comparative examples. Copper strip corrosion experiments were conducted on the prepared solutions. The weight loss of the copper strip, the amount of copper dissolved, and the color change of the copper strip surface were measured. The results are compared in Table 1.

[0105] In this test example, the copper strip corrosion test was conducted according to the method of GB / T 5096-2017 "Petroleum Products Copper Strip Corrosion Test Method".

[0106] Table 1

[0107]

[0108]

[0109] As shown in Table 1, the copper sheet surface color change rating of the compositions in Examples 1-5 is as good as that of T571, which is superior to T561 and T551. Data on copper sheet weight loss and copper dissolution after the experiment show that the products of the Examples are better than T571, indicating that the compositions of the Examples exhibit excellent copper corrosion inhibition. Table 1 shows that Comparative Examples 1-3 and 4, although the product AC alone can achieve a copper sheet surface color change rating of 1b, its copper dissolution is significantly higher than that of the compositions in Examples 1-5, indicating that the corrosion inhibition effect of Comparative Examples 1-3 on copper sheets is worse than that of the compositions in Examples 1-5. The rust inhibitor T746 alone is also less effective at inhibiting copper corrosion, with a copper sheet surface color rating of only 2c, and the copper sheet weight loss and copper content in the solution are also much higher than those in Examples 1-5. This invention, by combining a benzotriazole derivative with a rust inhibitor, obtained the corrosion inhibitor composition of this invention, producing an unexpected synergistic effect and improving the performance of copper corrosion inhibition.

[0110] Experimental Example 2

[0111] Rust-preventive oils were formulated using Ⅱ+6 as the base oil according to the formulation table in Table 2. The formulated examples and comparative examples were characterized by flash point, acid value, humidity chamber, pour point, evaporation loss, liquid phase corrosion, and rotating oxygen bomb tests. The test methods and results are shown in Table 3.

[0112] Table 2

[0113]

[0114] Table 3

[0115]

[0116]

[0117] As shown in Table 3, the rust-preventive oil with the copper corrosion inhibitor prepared by this method showed a significant improvement in its antioxidant performance in the oxidation stability test (change in acid value after oxidation) and the rotating oxygen bomb test. Meanwhile, in Example 4, when the relative proportion of the rust inhibitor was reduced, the liquid phase corrosion and humidity chamber test results showed that the rust-preventive performance did not decrease. This indicates that the copper corrosion inhibitor composition prepared by this method not only enhances the copper corrosion inhibition function of the rust-preventive oil, but also has a synergistic effect, thus improving the rust-preventive performance to a certain extent.

[0118] The present application has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present application based on these embodiments, all of which fall within the protection scope of the present application.

Claims

1. A corrosion inhibitor composition, characterized in that, The corrosion inhibitor composition comprises: Formula I compound Rust inhibitor; Among them, R1, R2, R3, and R4 may be the same as or different from each other, and each is independently selected from hydrogen, C 1-20 A straight-chain or branched hydrocarbon group, and at least one of R2 and R3 is not hydrogen; R5, R6, and R7 are each independently selected from C. 1-20 Straight-chain or branched hydrocarbon groups.

2. The corrosion inhibitor composition according to claim 1, characterized in that, The rust inhibitor is selected from one or more of dodecenyl succinic acid and heptadecanyl imidazolinyl succinate; and / or R1 is selected from C 1-20 Branched alkyl groups; Preferably, the mass ratio of the compound of formula I to the rust inhibitor is (3-1):1, more preferably (1-2.5):

1.

3. The corrosion inhibitor composition according to claim 1 or 2, characterized in that, The corrosion inhibitor composition also includes at least one of extreme pressure anti-wear agent, antioxidant, and antifoaming agent; Preferably, the extreme pressure anti-wear agent is selected from one or more of tricresyl phosphate, nitrogen-containing derivatives of thiophosphate, and mixtures of acidic phosphate amine salts, and is preferably tricresyl phosphate; Preferably, the antioxidant is selected from one or more of N-phenyl-α-naphthylamine, 2,6-di-tert-butyl-p-cresol, and alkyl diphenylamine, and more preferably N-phenyl-α-naphthylamine and / or 2,6-di-tert-butyl-p-cresol; and / or Preferably, the antifoaming agent is selected from one or more of methyl silicone oil, amine and ethylene oxide condensate, and is preferably methyl silicone oil.

4. A method for preparing the corrosion inhibitor composition according to any one of claims 1 to 3, comprising: (1) Compound II is reacted with a tertiary carbon amine in a solvent to prepare compound I, the structure of which is: Among them, R1, R2, R3, and R4 may be the same as or different from each other, and each is independently selected from hydrogen, C 1-20 A straight-chain or branched hydrocarbon group, and at least one of R2 and R3 is not hydrogen; (2) The compound of formula I prepared in step (1) is mixed with a rust inhibitor to obtain the corrosion inhibitor composition.

5. The method according to claim 4, characterized in that, In step (1), the tertiary primary amine is selected from C 12-14 One or more of tertiary alkylamines and dodecyl-dimethylamines; and / or The solvent is a protic solvent, preferably one or more of methanol, ethanol, and water.

6. The method according to claim 4, characterized in that, In step (1), the molar ratio of the compound of formula II to the tertiary carbon primary amine is 1:1 to 1.5, preferably 1:1 to 1.

3.

7. The method according to claim 4, characterized in that, In step (1), after the compound of formula II and the tertiary carbon primary amine are added to the solvent, they are first heated and stirred at a first temperature, and then heated and refluxed at a second temperature.

8. The method according to claim 7, characterized in that, The first temperature is 45℃~55℃; The heating and stirring time is 1 hour to 1.5 hours; The second temperature is 75℃~100℃, preferably 75℃~90℃; and / or The heating reflux time is 3 to 12 hours, preferably 4 to 8 hours.

9. The method according to any one of claims 4 to 8, characterized in that, Step (1) also includes: purifying the obtained compound of formula I; Preferably, the purification method is selected from one or more of the following: washing, distillation, filtration, drying, and recrystallization.

10. A lubricating oil, comprising: The corrosion inhibitor composition according to any one of claims 1 to 3 or the corrosion inhibitor composition prepared according to any one of claims 4 to 9.

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