Corrosion inhibitor composition

Abstract

The application discloses an inhibitor composition, which is composed of a compound shown in formula 1, a compound shown in formula 2 and water; the content of the compound shown in formula 1 is 15wt%-35wt%, and the content of the compound shown in formula 2 is 5wt%-20wt% based on the total mass of the inhibitor composition being 100%. The temperature-resistant inhibitor composition can significantly reduce the corrosion rate of metal, reduce the loss caused by corrosion, and can be widely applied to the fields of oilfield water injection, oil production, gathering and transportation, etc., and can protect the wellbore, pipeline and equipment of an oil-water well, and effectively alleviate the corrosion problem. The inhibitor composition can also be applied in an industrial circulating water system and a refining industry.

Description

Technical Field

[0001] This invention belongs to the field of corrosion protection of metallic materials, and specifically relates to a temperature-resistant corrosion inhibitor composition. Background Technology

[0002] my country's oil and gas field development has entered the medium-to-high water-cut stage, and corrosion problems in oil and gas production systems are becoming increasingly serious, causing staggering economic losses. Corrosion also interferes with normal oil and gas field production. Metal equipment such as casing, downhole pumps, sucker rods, and gathering pipes in oil and gas wells frequently suffer severe corrosion, hindering the development of oilfield technology and the improvement of oil extraction levels. Due to severe corrosion, many mature technologies are difficult to promote or achieve their intended effects. Some new processes, technologies, and equipment are difficult to use due to corrosion problems, and some technologies become more difficult to implement due to corrosion considerations.

[0003] Adsorption film-type corrosion inhibitors can adsorb onto metal surfaces, forming a monomolecular film across the entire anodic and cathodic regions. This alters the surface properties of the metal, thereby inhibiting or slowing down the corresponding electrochemical reactions. These compounds contain two groups with opposite properties: a lipophilic group and a hydrophilic group. The hydrophilic group adsorbs onto the metal surface, forming a dense hydrophobic film that protects the metal from corrosion.

[0004] Corrosion inhibitors are diverse in type and complex in mechanism. Currently, imidazoline corrosion inhibitors are widely used. While these inhibitors offer good corrosion inhibition, their poor water solubility limits their applicability. Conventional corrosion inhibitors are insufficient to effectively slow corrosion of wellbores and pipelines in oil and gas fields. As oil and gas field extraction depths increase and on-site operating environments become increasingly harsh, there is an urgent need to develop corrosion inhibitors with excellent corrosion inhibition performance under high-temperature conditions. Existing single-component corrosion inhibitors are insufficient to meet these requirements; therefore, developing corrosion inhibitors with good synergistic effects and high-temperature resistance is a major research direction for corrosion inhibitors in my country's oil and gas fields. Summary of the Invention

[0005] To address the above problems, the present invention provides a corrosion inhibitor composition.

[0006] The corrosion inhibitor composition of the present invention comprises a compound shown in Formula 1, a compound shown in Formula 2, and water; based on the total mass of the corrosion inhibitor composition as 100%, the content of the compound shown in Formula 1 is 15wt%-35wt%, preferably 20wt%-30wt%; and the content of the compound shown in Formula 2 is 5wt%-20wt%, preferably 10wt%-15wt%.

[0007]

[0008] In Formula 1, group R1 is C 4-28 Alkyl, preferably C12-18 n-alkyl group; R2 and R3 are each independently selected from CH3, C2H5, C3H7 or C4H9, preferably C2H5; X is Cl or Br;

[0009] In Equation 2, m is selected from any integer from 4 to 12; one of R4 and R5 is a hydroxyl group, and the other is... R6 and R7 are independently selected from C 12-18 alkyl, C 2-18 alkenyl group, C containing at least one oxygen atom 2-18 Alkyl groups, preferably n-dodecyl, n-tetradecyl, n-hexadecyl, or n-octadecyl.

[0010] According to one embodiment of the present invention, the preparation method of the compound shown in Formula 1 includes: weighing dialkyl secondary amine, hydrohalic acid, epichlorohydrin and solvent in proportion, adding them to a reaction apparatus and stirring to obtain an intermediate product; and taking the intermediate product, adjusting the pH value to a certain value with acid solution, adding alkyl dimethylamine, and stirring to react for a certain time at a certain temperature.

[0011] According to another embodiment of the present invention, the dialkyl secondary amine is selected from one of dimethylamine, diethylamine, N-ethylmethylamine, N-methylpropylamine, N-ethylpropylamine, dipropylamine, dibutylamine or N-propylbutylamine.

[0012] According to another embodiment of the present invention, the hydrohalic acid is selected from either hydrochloric acid solution or hydrogen bromide solution.

[0013] According to another embodiment of the present invention, the solvent is selected from one or a mixture of several of tap water, distilled water, ethanol, n-propanol, and isopropanol, preferably distilled water.

[0014] According to another embodiment of the present invention, the molar ratio of the dialkyl secondary amine, the hydrogen ions in the hydrohalic acid, and the epichlorohydrin is 1:1:0.95 to 1:1:1, preferably 1:1:0.98 to 1:1:1.

[0015] According to another embodiment of the present invention, the reaction temperature for generating the intermediate product is 50-70°C, preferably 60-65°C.

[0016] According to another embodiment of the present invention, the reaction time for generating the intermediate product is 2-10 hours, preferably 5-7 hours.

[0017] According to another embodiment of the present invention, the acid solution is selected from either hydrochloric acid solution or hydrogen bromide solution.

[0018] According to another embodiment of the present invention, the pH value is adjusted to 5.5-6.5, preferably 6.0.

[0019] According to another embodiment of the present invention, the alkyl dimethyl tertiary amine is selected from those with an alkyl carbon chain of C8-C9. 28 Alkyl dimethylamine, preferably dodecyl dimethyl tertiary amine, tetradecyl dimethyl tertiary amine, or hexadecyl dimethyl tertiary amine.

[0020] According to another embodiment of the present invention, the molar ratio of the intermediate product to the alkyl dimethyl tertiary amine is 0.95:1 to 1:1, preferably 0.98:1 to 1:1.

[0021] According to another embodiment of the present invention, the reaction temperature of the intermediate product with the alkyl dimethyl tertiary amine is 70-100°C, preferably 80-90°C.

[0022] According to another embodiment of the present invention, the reaction time of the intermediate product with the alkyl dimethyl tertiary amine is 2-10 hours, preferably 4-6 hours.

[0023] According to another embodiment of the present invention, the preparation method of the compound shown in Formula 2 includes: reacting an amino-functionalized cyclodextrin shown in Formula 3 with a 1,2-epoxyalkane shown in Formula 4 in the presence of a solvent;

[0024]

[0025] In Formula 3, m is selected from any integer from 4 to 12, preferably 5 to 7; one of R8 and R9 is -OH and the other is -NH2;

[0026]

[0027]

[0028] In Equation 4, R is selected from H and C. 1-18 alkyl, C 2-18 alkenyl group, C containing at least one oxygen atom 2-18 Alkyl groups, preferably n-dodecyl, n-tetradecyl, n-hexadecyl, or n-octadecyl.

[0029] According to another embodiment of the present invention, the reaction solvent is selected from one or more of methanol, ethanol, isopropanol, n-butanol, water, tetrahydrofuran, dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and ethylene glycol, preferably one of methanol-ethyl acetate, methanol-acetone, ethanol-ethyl acetate, and ethanol-acetone.

[0030] According to another embodiment of the present invention, the amino-functionalized cyclodextrin shown in Formula 3 is selected from one or more of amino-functionalized α-cyclodextrin, amino-functionalized β-cyclodextrin, and amino-functionalized γ-cyclodextrin.

[0031] According to another embodiment of the present invention, the 1,2-epoxyalkane in Formula 4 is selected from 1,2-epoxydodecane, 1,2-epoxytetradecane, 1,2-epoxyhexadecane, and 1,2-epoxyoctadecane.

[0032] According to another embodiment of the present invention, the reaction temperature is 30–100°C, preferably 60–90°C.

[0033] According to another embodiment of the present invention, the reaction time is 1 to 7 days, preferably 2 to 5 days.

[0034] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0035] (1) The nitrogen and oxygen atoms in the compounds shown in Formulas 1 and 2 give the corrosion inhibitors good adsorption properties. The lone pairs of electrons on the nitrogen and oxygen atoms form coordinate bonds with the empty d orbitals of the metal atoms, changing the activation energy of the metal surface, effectively inhibiting the anodic reaction and slowing down metal corrosion. The long-chain alkanes in the compounds shown in Formulas 1 and 2, as nonpolar groups, also oriented on the metal surface, reducing the contact opportunity between the metal surface and the corrosive medium, thus playing a role in slowing down corrosion.

[0036] (2) The compounds shown in Formula 1 and Formula 2 both contain amine groups, multiple hydroxyl groups, and long-chain alkane groups in their molecular structures, exhibiting good compounding properties and producing a synergistic effect. They can form a complete, dense, and firm protective film on the metal surface, demonstrating good corrosion inhibition effects. In addition, after the two compounds are adsorbed on the metal surface, they can also change the wettability of the metal surface, effectively slowing down the metal corrosion rate.

[0037] (3) The compound shown in Formula 2 contains a cyclodextrin polysaccharide head group, which makes it highly biocompatible, easily biodegradable, and will not cause secondary pollution.

[0038] (4) The corrosion inhibitor composition has advantages such as high temperature resistance, high salt resistance, and strong erosion resistance, and can be used in deep wells, ultra-deep wells, complex formation conditions and environments with stringent requirements for casing performance. Detailed Implementation

[0039] The present invention will now be described in detail with reference to specific embodiments.

[0040] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0041] The corrosion inhibitor composition of the present invention comprises the compound shown in Formula 1, the compound shown in Formula 2, and water;

[0042]

[0043] In Formula 1, group R1 is C 4-28 Alkyl, preferably C 12-18 n-alkyl group; R2 and R3 are each independently selected from CH3, C2H5, C3H7 or C4H9, preferably C2H5; X is Cl or Br;

[0044] In Equation 2, m is selected from any integer from 4 to 12; one of R4 and R5 is a hydroxyl group, and the other is... R6 and R7 are independently selected from C 12-18 alkyl, C 2-18 alkenyl group, C containing at least one oxygen atom 2-18 The alkyl group is preferably dodecyl, tetradecyl, hexadecyl, or octadecyl. Based on 100% of the total mass of the corrosion inhibitor composition, the content of the compound shown in Formula 1 is 15 wt%-35 wt%, preferably 20 wt%-30 wt%; and the content of the compound shown in Formula 2 is 5 wt%-20 wt%, preferably 10 wt%-15 wt%.

[0045] The corrosion inhibitor compositions of the present invention, wherein the nitrogen and oxygen atoms in the compounds shown in Formulas 1 and 2 give the corrosion inhibitors excellent adsorption properties, and the lone pairs of electrons on the nitrogen and oxygen atoms form coordinate bonds with the empty d orbitals of the metal atoms, changing the activation energy of the metal surface, effectively inhibiting the anodic reaction, and slowing down metal corrosion. The long-chain alkanes in the compounds shown in Formulas 1 and 2, as nonpolar groups, also oriented on the metal surface, reducing the contact opportunity between the metal surface and the corrosive medium, thus slowing down corrosion. The molecular structures of the compounds shown in Formulas 1 and 2 both contain amine groups, multiple hydroxyl groups, and long-chain alkanes, exhibiting good compounding properties and producing a synergistic effect. They can form a complete, dense, and robust protective film on the metal surface, demonstrating excellent corrosion inhibition. Furthermore, after the two compounds are adsorbed onto the metal surface, they can also change the wettability of the metal surface, effectively slowing down the metal corrosion rate. Moreover, the compound shown in Formula 2 contains a cyclodextrin polysaccharide head group, giving it strong biocompatibility, easy biodegradability, and no secondary pollution.

[0046] In an optional embodiment, the preparation method of the compound shown in Formula 1 includes: weighing dialkyl secondary amine, hydrohalic acid, epichlorohydrin and solvent in proportion, adding them to a reaction apparatus and stirring to obtain an intermediate product; and taking the intermediate product, adjusting the pH value to a certain value with acid solution, adding alkyl dimethylamine, and stirring to react for a certain time at a certain temperature.

[0047] The dialkyl secondary amine can be selected from one of dimethylamine, diethylamine, N-ethylmethylamine, N-methyl-n-propylamine, N-ethyl-n-propylamine, dipropylamine, dibutylamine, or N-propylbutylamine. The hydrohalic acid can be selected from one of hydrochloric acid solution or hydrogen bromide solution. The solvent can be one or a mixture of several of tap water, distilled water, ethanol, n-propanol, and isopropanol, preferably distilled water. The molar ratio of hydrogen ions to epichlorohydrin in the dialkyl secondary amine and hydrohalic acid is 1:1:0.95 to 1:1:1, preferably 1:1:0.98 to 1:1:1. The reaction temperature for generating the intermediate product is 50-70℃, preferably 60-65℃. The reaction time for generating the intermediate product is 2-10 hours, preferably 5-7 hours.

[0048] The acid solution used to adjust the pH value is either hydrochloric acid or hydrogen bromide solution. The pH value is adjusted to 5.5-6.5, preferably 6.0. The alkyl dimethyl tertiary amine is selected with an alkyl carbon chain of C8-C6. 28 The intermediate product is preferably an alkyl dimethylamine, dodecyl dimethyl tertiary amine, tetradecyl dimethyl tertiary amine, or hexadecyl dimethyl tertiary amine. The molar ratio of the intermediate product to the alkyl dimethyl tertiary amine is 0.95:1 to 1:1, preferably 0.98:1 to 1:1. The reaction temperature of the intermediate product with the alkyl dimethyl tertiary amine is 70-100°C, preferably 80-90°C. The reaction time of the intermediate product with the alkyl dimethyl tertiary amine is 2-10 hours, preferably 4-6 hours.

[0049] In an optional embodiment, the preparation method of the compound shown in Formula 2 includes: reacting the amino-functionalized cyclodextrin shown in Formula 3 with the 1,2-epoxyalkane shown in Formula 4 in the presence of a solvent.

[0050]

[0051] In Formula 3, m is selected from any integer from 4 to 12, preferably 5 to 7; one of R8 and R9 is -OH and the other is -NH2;

[0052]

[0053] In Equation 4, R is selected from H and C. 1-18 alkyl, C 2-18 alkenyl group, C containing at least one oxygen atom 2-18 Alkyl groups, preferably n-dodecyl, n-tetradecyl, n-hexadecyl, or n-octadecyl.

[0054] In optional embodiments, the reaction solvent is selected from one or more of methanol, ethanol, isopropanol, n-butanol, water, tetrahydrofuran, dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and ethylene glycol, preferably one of methanol-ethyl acetate, methanol-acetone, ethanol-ethyl acetate, and ethanol-acetone. The amino-functionalized cyclodextrin shown in Formula 3 is selected from one of amino-functionalized α-cyclodextrin, amino-functionalized β-cyclodextrin, and amino-functionalized γ-cyclodextrin. The 1,2-epoxyalkane in Formula 4 is selected from 1,2-epoxydodecane, 1,2-epoxytetradecane, 1,2-epoxyhexadecane, and 1,2-epoxyoctadecane. The reaction temperature is 30–100°C, preferably 60–90°C. The reaction time is 1–7 days, preferably 2–5 days.

[0055] The corrosion inhibitor composition of the present invention can be formed by any method. For example, but not limited to: adding a certain amount of the quaternary ammonium salt compound containing tertiary amine and hydroxyl group as shown in Formula 1, the modified compound based on amino-functionalized cyclodextrin as shown in Formula 2, and water to a reaction vessel, and stirring until homogeneous to obtain the temperature-resistant corrosion inhibitor composition. Preferably, the mixing conditions at least satisfy the following: temperature of 5-40°C and stirring time of 20-60 min.

[0056] The corrosion inhibitor composition of this invention is used for corrosion prevention in water well injection, water well acidizing, oil well production, oil well acidizing, pipeline gathering and transportation, and CO2 enhanced oil recovery during oil and gas field development. It is also suitable for corrosion prevention applications in industrial circulating water systems and the oil refining industry.

[0057] The inventive concept of the present invention will be explained in detail below with reference to the embodiments. In the following embodiments, unless otherwise specified, all reagents used are commercially available chemical reagents, and there are no particular limitations in this regard.

[0058] Some of the raw materials used in the preparation examples, embodiments, and comparative examples are shown in Table 1:

[0059] Table 1: Partial List of Raw Material Manufacturers, Batch Numbers, and Purity

[0060]

[0061] Preparation Example 1

[0062] The quaternary ammonium salt containing a tertiary amine and a hydroxyl group as described in Formula 1 is abbreviated as J-1 when R1 is n-dodecyl and R2 and R3 are both ethyl. The synthesis reaction process of J-1 is as follows:

[0063]

[0064] The specific synthesis steps are as follows: 0.2 mol of diethylamine was placed in a 500 mL three-necked flask, stirred, and 100 mL of 2 mol / L hydrochloric acid solution was slowly added. Then, 0.2 mol of epichlorohydrin was added at a dropping rate of 3-5 seconds per drop. Next, 80 mL of distilled water was added. The reaction was carried out at 60 °C for 6 hours, yielding a pale yellow mixture. The pH of the mixture was adjusted to 6.1 with hydrochloric acid. 0.2 mol of dodecyl dimethyl tertiary amine was then added. The reaction was carried out at 85 °C for 5 hours. The solvent in the product was removed using a rotary evaporator. The solid was washed three times with n-hexane and recrystallized three to five times with acetone to obtain a white solid. This yielded compound J-1.

[0065] Preparation Example 2

[0066] The quaternary ammonium salt containing a tertiary amine and a hydroxyl group as described in Formula 1 is abbreviated as J-2 when R1 is n-hexadecyl and R2 and R3 are both propyl. The specific synthetic steps are as follows: 0.2 mol of dipropylamine is placed in a 500 mL three-necked flask, stirred, and 100 mL of 2 mol / L hydrochloric acid solution is slowly added. Then, 0.2 mol of epichlorohydrin is added at a dropping rate of 3-5 seconds / drop. Afterward, 90 mL of distilled water is added. The reaction is continued at 65 °C for 5 hours to obtain a pale yellow mixture. The pH of the mixture is adjusted to 6.0 with hydrochloric acid. 0.2 mol of hexadecyl dimethyl tertiary amine is then added. The reaction is continued at 90 °C for 4 hours. The solvent in the product is removed using a rotary evaporator. The solid is washed three times with n-hexane and recrystallized three to five times with acetone to obtain a white solid. This is compound J-2.

[0067] Preparation Example 3

[0068] The modified compound based on amino-functionalized cyclodextrin described in Formula 2, when m = 6, R4 is When R5 is a hydroxyl group and R6 and R7 are n-dodecyl groups, the structure shown in Formula 2 is compound Z-1.

[0069]

[0070] Compound Z-1, shown in Formula 2, was prepared based on aminolated β-cyclodextrin:

[0071] Weigh 1.134 g of mono-(6-amino-6-deoxy)-β-cyclodextrin and 0.85 g of 1,2-epoxytetradecane into a reaction flask, then add 20 mL of anhydrous ethanol and stir until homogeneous. Stir the reaction mixture at 75 °C for 72 h, then stop the reaction and remove the solvent by rotary evaporation. Recrystallize the residue using an ethanol / acetone mixture to obtain compound Z-1.

[0072] Preparation Example 4

[0073] The modified compound based on amino-functionalized cyclodextrin described in Formula 2, when m = 5, R4 is a hydroxyl group and R5 is a... When R6 and R7 are n-dodecyl, the structure shown in Formula 2 is compound Z-2.

[0074] Compound Z-2, as shown in Formula 2, was prepared based on aminated α-cyclodextrin:

[0075] 0.972 g of 3A-amino-3A-deoxy-(2AS,3AS)-α-cyclodextrin hydrate and 0.85 g of 1,2-epoxytetradecane were weighed into a reaction flask, and then 20 mL of anhydrous ethanol was added and stirred until homogeneous. The reaction was stirred at 75 °C for 72 h, after which the reaction was stopped, and the solvent was removed by rotary evaporation. The residue was recrystallized from the ethanol / acetone mixture to obtain compound Z-2.

[0076] Corrosion inhibitor compositions were prepared using compounds J-1, J-2, Z-1, and Z-2 prepared according to preparations 1-4. In the following examples, "parts by weight" refers to 0.5 g.

[0077] Example 1

[0078] At 30°C, 32 parts by weight of J-1, 12 parts by weight of Z-1, and 56 parts by weight of water were added to a reaction vessel and stirred for 30 minutes to obtain a temperature-resistant corrosion inhibitor composition, designated HJ-1.

[0079] Example 2

[0080] At 15°C, 32 parts by weight of J-1, 12 parts by weight of Z-2, and 56 parts by weight of water were added to the reactor and stirred for 35 minutes to obtain a temperature-resistant corrosion inhibitor composition, designated HJ-2.

[0081] Example 3

[0082] At 20°C, 32 parts by weight of J-2, 12 parts by weight of Z-1, and 56 parts by weight of water were added to the reactor and stirred for 40 minutes to obtain a temperature-resistant corrosion inhibitor composition, designated HJ-3.

[0083] Example 4

[0084] At 25°C, 32 parts by weight of J-2, 12 parts by weight of Z-2, and 56 parts by weight of water were added to the reactor and stirred for 25 minutes to obtain a temperature-resistant corrosion inhibitor composition, designated HJ-4.

[0085] Example 5

[0086] At 20°C, 30 parts by weight of J-1, 10 parts by weight of Z-2, and 60 parts by weight of water were added to the reactor and stirred for 35 minutes to obtain a temperature-resistant corrosion inhibitor composition, designated HJ-5.

[0087] Example 6

[0088] At 15°C, 25 parts by weight of J-1, 8 parts by weight of Z-2, and 67 parts by weight of water were added to the reactor and stirred for 35 minutes to obtain a temperature-resistant corrosion inhibitor composition, designated HJ-6.

[0089] Example 7

[0090] At 25°C, 15 parts by weight of J-1, 5 parts by weight of Z-2, and 80 parts by weight of water were added to the reactor and stirred for 35 minutes to obtain a temperature-resistant corrosion inhibitor composition, designated HJ-7.

[0091] Example 8

[0092] At 25°C, 20 parts by weight of J-1, 15 parts by weight of Z-2, and 65 parts by weight of water were added to a reaction vessel and stirred for 35 minutes to obtain a temperature-resistant corrosion inhibitor composition, designated HJ-8.

[0093] Example 9

[0094] At 25°C, 35 parts by weight of J-1, 20 parts by weight of Z-2, and 45 parts by weight of water were added to a reaction vessel and stirred for 35 minutes to obtain a temperature-resistant corrosion inhibitor composition, designated HJ-9.

[0095] Comparative Example 1

[0096] At 20°C, 44 parts by weight of J-1 and 56 parts by weight of water were added to the reactor and stirred for 35 minutes to obtain the corrosion inhibitor, designated DB-1.

[0097] Comparative Example 2

[0098] At 20°C, 44 parts by weight of J-2 and 56 parts by weight of water were added to the reactor and stirred for 35 minutes to obtain the corrosion inhibitor, designated DB-2.

[0099] Comparative Example 3

[0100] At 20°C, 44 parts by weight of Z-1 and 56 parts by weight of water were added to the reactor and stirred for 30 minutes to obtain the corrosion inhibitor, designated DB-3.

[0101] Comparative Example 4

[0102] At 20°C, 44 parts by weight of Z-2 and 56 parts by weight of water were added to the reactor and stirred for 30 minutes to obtain the corrosion inhibitor, designated DB-4.

[0103] Comparative Example 5

[0104] The corrosion inhibitor used in a certain oil field is an industrial product, code-named DB-5.

[0105] Test Example 1

[0106] Corrosion inhibition performance evaluation: The weight loss method using immersion plates (50mm × 10mm × 3mm) was employed. The corrosion rate under certain conditions was determined by accurately weighing the difference in mass of the metal sample before and after immersion in the corrosive medium. Specifically, the weighed A3 steel sheets were immersed in 20% hydrochloric acid solutions (with and without corrosion inhibitor) at 60℃ for 4 hours. After immersion, the steel sheets were removed, immediately rinsed with water, scrubbed with a soft brush, dried with cold air, and then weighed again to calculate the corrosion inhibition rate.

[0107] Formula for calculating corrosion rate v:

[0108]

[0109] In the formula:

[0110] m0 — Mass of the steel sheet before it is hung, in grams;

[0111] m — the mass of the steel sheet after it is hung up, in grams;

[0112] s — Surface area of ​​the steel sheet, cm 2 ;

[0113] t — Experiment time, h.

[0114] Formula for calculating corrosion inhibition rate η:

[0115]

[0116] In the formula:

[0117] v0 — Corrosion rate of the steel sheet in the blank experiment, g / m 2 ·h.

[0118] v — Corrosion rate of the steel sheet in the test with added corrosion inhibitor, g / m 2 ·h.

[0119] The corrosion inhibition rates of different corrosion inhibitor compositions with a mass fraction of 0.5% are shown in Table 2.

[0120] Test Example 2

[0121] Temperature resistance evaluation: The corrosion inhibitor composition was placed in an oven at 130℃ and left to stand for 24 hours. After cooling, the corrosion inhibition rate of the corrosion inhibitor was tested according to the method in Test Example 1. The corrosion inhibition rate test results are shown in Table 2.

[0122] Table 2 Corrosion inhibition rate of different corrosion inhibitor compositions

[0123]

[0124] It can be seen that the corrosion inhibitor composition provided by the present invention can significantly inhibit the corrosion process and has good temperature resistance, up to 130℃.

[0125] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A corrosion inhibitor composition, characterized in that, It consists of the compound shown in Formula 1, the compound shown in Formula 2, and water; In Formula 1, group R1 is C 12-18 n-alkyl; R2 and R3 are each independently selected from CH3, C2H5, C3H7 or C4H9; X is Cl or Br; In Equation 2, m is selected from any integer from 4 to 12; one of R4 and R5 is a hydroxyl group, and the other is a... R6 and R7 are independently selected from n-dodecyl, n-tetradecyl, n-hexadecyl, and n-octadecyl; Based on the total mass of the corrosion inhibitor composition as 100%, the content of the compound shown in Formula 1 is 15wt%-35wt%; and the content of the compound shown in Formula 2 is 5wt%-20wt%.

2. The corrosion inhibitor composition according to claim 1, characterized in that, The content of the compound shown in Formula 1 is 20wt%-30wt%; the content of the compound shown in Formula 2 is 10wt%-15wt%.

3. The corrosion inhibitor composition according to claim 1, characterized in that, The preparation method of the compound shown in Formula 1 includes: Weigh out the dialkyl secondary amine, hydrohalic acid, epichlorohydrin, and solvent in proportion, add them to the reaction apparatus, and stir to obtain the intermediate product; and Take the intermediate product, adjust the pH value to a certain value with acid, add alkyl dimethyl tertiary amine, and stir the reaction at a certain temperature for a certain time.

4. The corrosion inhibitor composition according to claim 3, characterized in that, The dialkyl secondary amine is selected from one of dimethylamine, diethylamine, N-ethylmethylamine, N-methylpropylamine, N-ethylpropylamine, dipropylamine, dibutylamine, or N-propylbutylamine.

5. The corrosion inhibitor composition according to claim 3, characterized in that, The hydrohalic acid is selected from either hydrochloric acid solution or hydrogen bromide solution.

6. The corrosion inhibitor composition according to claim 3, characterized in that, The solvent is selected from one or a mixture of several of the following: tap water, distilled water, ethanol, n-propanol, and isopropanol.

7. The corrosion inhibitor composition according to claim 3, characterized in that, The molar ratio of hydrogen ions in the dialkyl secondary amine and the hydrohalic acid to epichlorohydrin is 1:1:0.95 to 1:1:

1.

8. The corrosion inhibitor composition according to claim 7, characterized in that, The molar ratio of hydrogen ions in the dialkyl secondary amine and the hydrohalic acid to epichlorohydrin is 1:1:0.98 to 1:1:

1.

9. The corrosion inhibitor composition according to claim 3, characterized in that, The reaction temperature for generating the intermediate product is 50-70℃.

10. The corrosion inhibitor composition according to claim 9, characterized in that, The reaction temperature for generating the intermediate product is 60-65℃.

11. The corrosion inhibitor composition according to claim 3, characterized in that, The reaction time for generating the intermediate product is 2-10 hours.

12. The corrosion inhibitor composition according to claim 11, characterized in that, The reaction time for generating the intermediate product is 5-7 hours.

13. The corrosion inhibitor composition according to claim 3, characterized in that, The acid solution is selected from either hydrochloric acid solution or hydrogen bromide solution.

14. The corrosion inhibitor composition according to claim 3, characterized in that, Adjust the pH value to 5.5-6.

5.

15. The corrosion inhibitor composition according to claim 14, characterized in that, Adjust the pH value to 6.

0.

16. The corrosion inhibitor composition according to claim 3, characterized in that, The alkyl dimethyl tertiary amine is selected from dodecyl dimethyl tertiary amine, tetradecyl dimethyl tertiary amine, and hexadecyl dimethyl tertiary amine.

17. The corrosion inhibitor composition according to claim 3, characterized in that, The molar ratio of the intermediate product to the alkyl dimethyl tertiary amine is 0.95:1 to 1:

1.

18. The corrosion inhibitor composition according to claim 17, characterized in that, The molar ratio of the intermediate product to the alkyl dimethyl tertiary amine is 0.98:1 to 1:

1.

19. The corrosion inhibitor composition according to claim 3, characterized in that, The reaction temperature of the intermediate product with the alkyl dimethyl tertiary amine is 70-100℃.

20. The corrosion inhibitor composition according to claim 19, characterized in that, The reaction temperature of the intermediate product with the alkyl dimethyl tertiary amine is 80-90℃.

21. The corrosion inhibitor composition according to claim 3, characterized in that, The reaction time of the intermediate product with the alkyl dimethyl tertiary amine is 2-10 hours.

22. The corrosion inhibitor composition according to claim 21, characterized in that, The reaction time between the intermediate product and the alkyl dimethyl tertiary amine is 4-6 hours.

23. The corrosion inhibitor composition according to claim 1, characterized in that, The preparation method of the compound shown in Formula 2 includes: In the presence of a solvent, the amino-functionalized cyclodextrin shown in Formula 3 is reacted with the 1,2-epoxyalkane shown in Formula 4. In Equation 3, m is selected from any integer from 4 to 12; one of R8 and R9 is -OH and the other is -NH2; In Formula 4, R is selected from n-dodecyl, n-tetradecyl, n-hexadecyl, and n-octadecyl.

24. The corrosion inhibitor composition according to claim 23, characterized in that, m is any integer from 5 to 7.

25. The corrosion inhibitor composition according to claim 23, characterized in that, The solvent is selected from one or more of methanol, ethanol, isopropanol, n-butanol, water, tetrahydrofuran, dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and ethylene glycol.

26. The corrosion inhibitor composition according to claim 25, characterized in that, The solvent is selected from one of methanol-ethyl acetate, methanol-acetone, ethanol-ethyl acetate, and ethanol-acetone.

27. The corrosion inhibitor composition according to claim 23, characterized in that, The amino-functionalized cyclodextrin shown in Formula 3 is selected from one or more of amino-functionalized α-cyclodextrin, amino-functionalized β-cyclodextrin, and amino-functionalized γ-cyclodextrin.

28. The corrosion inhibitor composition according to claim 23, characterized in that, The 1,2-epoxyalkane in Formula 4 is selected from 1,2-epoxydodecane, 1,2-epoxytetradecane, 1,2-epoxyhexadecane, and 1,2-epoxyoctadecane.

29. The corrosion inhibitor composition according to claim 23, characterized in that, The reaction temperature is 30~100℃.

30. The corrosion inhibitor composition according to claim 29, characterized in that, The reaction temperature is 60~90℃.

31. The corrosion inhibitor composition according to claim 23, characterized in that, The reaction time is 1 to 7 days.

32. The corrosion inhibitor composition according to claim 31, characterized in that, The reaction time is 2 to 5 days.

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