Modified quaternary ammonium salt, preparation method and corrosion inhibitor having modified quaternary ammonium salt

Abstract

The present invention is applicable to the field of drug protection and provides a modified quaternary ammonium salt, a preparation method, and a corrosion inhibitor having the modified quaternary ammonium salt. The introduction of ester bonds and other organic groups in the modified quaternary ammonium salt with a bactericidal effect has better affinity for microbial cell membranes, enhances its destructiveness to cell membranes, and improves the bactericidal ability of the quaternary ammonium salt. At the same time, the addition of the modified quaternary ammonium salt not only fills the gaps in the film layer formed by the imidazoline derivative on the metal surface, but also increases the thickness of the film layer, improves the shielding ability of the corrosion inhibitor film layer against corrosive media, and enhances the corrosion inhibition effect. The bactericidal corrosion inhibitor in the present invention is mainly used for corrosion protection of ground gathering and transportation pipelines in the process of oil and gas field development against the coexistence of bacterial corrosion and CO2 corrosion, and has the advantages of low dosage, significant effect, and low cost.

Description

Technical Field

[0001] The invention belongs to the field of pharmaceutical protection, and particularly relates to a modified quaternary ammonium salt, a preparation method and a corrosion inhibitor having the modified quaternary ammonium salt. Background Art

[0002] During the oil and gas extraction process, oil and gas field pipes face a combination of factors, including erosion from produced fluids, fluid erosion, and corrosive gases. Corrosion failure of these pipes has become a major obstacle to oil and gas production. As oil and gas field production enters the middle and late stages of development, and as deep, high-pressure CO2 oil and gas fields are developed, carbon steel and low-alloy steel pipes are susceptible to high corrosion rates, severe localized corrosion, and even perforation. Furthermore, microbial corrosion (MIC) is one of the most difficult forms of corrosion to control in oil and gas facilities. Due to the complexity and uncertainty of microbial activity, MIC is difficult to detect or predict. Microorganisms form distinct circular pits on the pipe surface, resulting in typical localized corrosion. With the development of oil and gas field production, corrosion has become a potential hazard in oil and gas production and transportation. Oil and gas fields in my country, such as the Tarim, Sichuan, North China, and Changqing regions, all contain significant amounts of CO2, and bacteria are present in the medium. This poses significant challenges to both downhole equipment and surface gathering and transportation equipment. Corrosion-related accidents frequently occur annually, causing significant economic losses and casualties to the country and enterprises, and hindering the normal production and operation of the entire oil and gas field.

[0003] In response to the bacterial corrosion caused by sulfate-reducing bacteria (SRB) and pipeline corrosion perforation caused by CO2 corrosion in oil and gas field gathering and transportation pipelines, the process of injecting corrosion inhibitors into the wellbore and the ground is often used for protection. At present, the fungicides widely used in oil fields are mainly quaternary ammonium compounds, such as dodecyldimethylbenzyl ammonium chloride (1227, also known as Chlorhexidine) and polymeric quaternary ammonium salts. Due to the large-scale use of these fungicides, they have a sorting effect on microorganisms, resulting in a decrease in sterilization efficiency, a large amount of agent addition, and an increase in economic cost investment. To this end, quaternary ammonium salt fungicides are modified to improve their sterilization performance, reduce the addition amount, and reduce costs. Summary of the Invention

[0004] In view of the above problems, on the one hand, the present invention discloses a modified quaternary ammonium salt, wherein the modified quaternary ammonium salt is:

[0005]

[0006] wherein R1 and R3 are H, —CH3, —C2H5, —OH, —C3H7 or —C2H4OH;

[0007] R2 is —CH3 or —C2H4—;

[0008] R4 is —CH3, —C2H5 or —H;

[0009] X is Cl;

[0010] n is 1 to 10.

[0011] Correspondingly, the preparation method of the modified quaternary ammonium salt includes:

[0012] At a specified temperature, adding a chloropropylene compound dropwise to an organic amine compound to carry out a heat-insulating reaction;

[0013] Then, organic acids are added to carry out esterification and the reaction is carried out at a temperature-insulating state;

[0014] After esterification, the temperature was lowered to below 40°C to terminate the reaction.

[0015] Furthermore, the organic amine compound, the chloropropylene compound and the organic acid are subjected to a synthesis reaction at a mass ratio of 1:1:1 under normal pressure.

[0016] Furthermore, the step of adding the chloropropylene compound dropwise to the organic amine compound at a specified temperature and performing the heat preservation reaction specifically includes:

[0017] Control the temperature to rise to 20-100°C at a rate of 1-2°C / min;

[0018] At a specified temperature of 20 to 100°C, a chlorinated allyl compound is added dropwise to the organic amine compound;

[0019] Control the temperature between 40 and 110°C and keep it warm for 1 to 3 hours.

[0020] Furthermore, the organic acid is added for esterification and the heat preservation reaction is carried out, and the heat preservation reaction specifically refers to:

[0021] Control the temperature within the range of 40℃~110℃ and keep warm for 1 hour.

[0022] Furthermore, the carbon content of the organic amine compound is C1 to C14.

[0023] Furthermore, the chloropropylene compound is a 3-chloropropylene alcohol compound.

[0024] Furthermore, the carbon content of the organic acid compound is C1-C3.

[0025] Furthermore, during the heat preservation reaction, the temperature is raised to 40-110° C. at a rate of 1-2° C. / min.

[0026] A corrosion inhibitor with modified quaternary ammonium salt comprises, calculated by mass percentage, 60-70% of modified quaternary ammonium salt, 10-30% of imidazoline derivative and 10-30% of water solvent.

[0027] Furthermore, the corrosion inhibitor comprises, calculated by mass percentage, 60-70% of modified quaternary ammonium salt, 10-20% of imidazoline derivative, and 20-30% of water solvent.

[0028] Furthermore, the corrosion inhibitor comprises, calculated by mass percentage, 60-70% of modified quaternary ammonium salt, 20-30% of imidazoline derivative, and 10-20% of aqueous solvent.

[0029] Furthermore, the imidazoline derivative is an imidazoline quaternary ammonium salt or an imidazoline sebacate or an oleate or a mixture of an oleate and a dimerate.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The introduction of ester bond and other organic groups in the modified quaternary ammonium salt with bactericidal effect in the present invention has better affinity to microbial cell membrane, strengthens its destructiveness to cell membrane, and improves the bactericidal ability of quaternary ammonium salt. Simultaneously, the addition of modified quaternary ammonium salt not only fills the gap of the film formed by imidazoline derivatives on the metal surface, but also increases the film thickness, improves the shielding ability of the corrosion inhibitor film to corrosive media, and strengthens the corrosion inhibition effect. The bactericidal corrosion inhibitor in the present invention is mainly used for the corrosion protection of ground gathering and transportation pipeline bacterial corrosion and CO2 corrosion coexistence in the oil and gas field development process, has the advantages of few consumption, remarkable effect, and low cost. Test results show that this bactericidal corrosion inhibitor has significant bactericidal effect, for containing CO2, the corrosion under the bacterial working environment has good inhibitory effect.

[0032] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 Schematic diagram of the reaction involved in the preparation example of the modified quaternary ammonium salt of the present invention. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0036] The present invention is a bactericidal corrosion inhibitor prepared by using modified quaternary ammonium salt as main agent, compounding imidazoline derivatives and diluting with water. The bactericidal corrosion inhibitor is mainly used for corrosion protection of oil and gas field gathering and transportation pipelines where bacterial corrosion and CO2 corrosion coexist.

[0037] A corrosion inhibitor for gathering and transportation pipelines with a bactericidal function comprises, by weight percentage, 60-70% of a modified quaternary ammonium salt, 10-30% of an imidazoline derivative, and 10-30% of an aqueous solvent.

[0038] The modified quaternary ammonium salt is obtained by the following steps: mixing an organic amine compound with a carbon content of C1 to C14, a 3-chloropropenol compound and an organic acid compound with a carbon content of C1 to C3 at a mass ratio of 1:1:1 under normal pressure.

[0039] Step 1: slowly adding a chloropropylene compound dropwise to an organic amine compound at a temperature of 20 to 100° C.; wherein the temperature is increased to 20 to 100° C. at a rate of 1 to 2° C. / min;

[0040] Step 2: Heat to 40-110°C at a rate of 1-2°C / min and keep warm for 1-3 hours; the reaction formula is Figure 1 Chemical formula Ⅰ in

[0041] Step 3: Then add organic acid to carry out esterification; the reaction formula is Figure 1 Chemical formula II;

[0042] Step 4: Keep the temperature within the range of 40°C to 110°C for 1 hour and then cool it to below 40°C to obtain the modified quaternary ammonium salt.

[0043] The imidazoline derivative can be imidazoline quaternary ammonium salt, imidazoline sebacate, oleate, or a mixture of oleate and dimerate.

[0044] The chemical formula of the modified quaternary ammonium salt is:

[0045]

[0046] Wherein, R1 and R3 are H, —CH3, —C2H5, —OH, —C3H7, —C2H4OH;

[0047] R2 is —CH3, —C2H4—;

[0048] R4 is —CH3, —C2H5, or —H;

[0049] X is Cl;

[0050] n is 1 to 10.

[0051] The preparation method of the corrosion inhibitor for gathering and transportation pipelines with a sterilization function of the present invention comprises the following steps: calculating by mass percentage, uniformly mixing 60-70% of a modified quaternary ammonium salt, 10-30% of an imidazoline derivative, and 10-30% of an aqueous solvent.

[0052] The corrosion rate and bactericidal effect determination methods in each embodiment of the present invention are as follows: the corrosion rate and bactericidal effect are determined by referring to the methods recommended in the standards "GB / T33509 Application of Corrosion Inhibitors in Oil and Gas Fields" and "SY / T 5890-93 Bactericide Performance Evaluation Method". Medium composition: Cl - :2000mg / L、SO4 2- :10mg / L、Ca 2+ :500mg / L、Na + : 12385.5 mg / L. Furthermore, the dissolved oxygen content in the solution was less than 10 ppb, the SRB bacterial count was 250 cells / mL, and the TGB bacterial count was 400 cells / mL. Test temperature: 40°C; test period: 120 hours; test material: L245N. After degreasing and drying, the L245N steel specimens were installed in a reactor and deoxygenated with nitrogen for 4 hours. The deoxygenated test solution was then pressurized, with a bactericidal corrosion inhibitor dosage of 100 ppm. CO2 was introduced to saturation, and the temperature was raised to 40°C. After 120 hours, the specimens were removed, their surface corrosion products cleaned, dried, weighed, and the corrosion rate calculated.

[0053] Example 1

[0054] The modified quaternary ammonium salt is obtained by the following process: a C1-C14 organic amine compound, a 3-chloropropenol compound, and a C1-C3 organic acid compound are mixed at a mass ratio of 1:1:1 under normal pressure. First, the chloropropenol compound is slowly added dropwise to the organic amine compound at 20°C. The temperature is raised to 110°C at a rate of 1°C / min and maintained for 3 hours. Then, the organic acid is added for esterification. After maintaining the temperature at 110°C for 1 hour, the temperature is lowered to below 40°C to obtain the modified quaternary ammonium salt.

[0055] The bactericidal corrosion inhibitor is composed of the following components in weight percentage: 60% modified quaternary ammonium salt, 20% imidazoline quaternary ammonium salt, and 20% aqueous solvent. The bactericidal corrosion inhibitor has good water solubility in the test medium, a corrosion rate of 0.087 mm / a, and a bactericidal rate of 95%.

[0056] Example 2

[0057] The modified quaternary ammonium salt is obtained by the following process: a C1-C14 organic amine compound, a 3-chloropropenol compound, and a C1-C3 organic acid compound are mixed at a mass ratio of 1:1:1 under normal pressure. First, the chloropropenol compound is slowly added dropwise to the organic amine compound at 40°C. The temperature is raised to 80°C at a rate of 1°C / min and maintained for 3 hours. Then, the organic acid is added for esterification. The temperature is maintained at 110°C for 1 hour, then cooled to below 40°C to obtain the modified quaternary ammonium salt.

[0058] The bactericidal corrosion inhibitor is composed of the following components by weight: 60% modified quaternary ammonium salt, 20% imidazoline quaternary ammonium salt, and 20% aqueous solvent. The bactericidal corrosion inhibitor exhibited good water solubility in the test medium, resulting in a corrosion rate of 0.075 mm / a and a bactericidal efficiency of 95%. The decrease in corrosion rate was attributed to both errors in the test process and the temperature at which the modified quaternary ammonium salt was prepared. Based on subsequent implementation cases, it is speculated that the decrease in corrosion rate is primarily due to the reduction in temperature, which facilitates the synthesis of the modified quaternary ammonium salt.

[0059] Example 3

[0060] The modified quaternary ammonium salt is obtained by the following process: a C1-C14 organic amine compound, a 3-chloropropenol compound, and a C1-C3 organic acid compound are mixed at a mass ratio of 1:1:1 under normal pressure. First, the chloropropenol compound is slowly added dropwise to the organic amine compound at 60°C. The temperature is raised to 40°C at a rate of 1°C / min and maintained for 3 hours. The organic acid is then added for esterification. The temperature is maintained at 110°C for 1 hour, then cooled to below 40°C to obtain the modified quaternary ammonium salt.

[0061] The bactericidal corrosion inhibitor is composed of the following components in weight percentage: 60% modified quaternary ammonium salt, 20% imidazoline quaternary ammonium salt, and 20% aqueous solvent. The bactericidal corrosion inhibitor has good water solubility in the test medium, a corrosion rate of 0.073 mm / a, and a bactericidal rate of 95%.

[0062] Example 4

[0063] The modified quaternary ammonium salt is obtained by the following process: a C1-C14 organic amine compound, a 3-chloropropenol compound, and a C1-C3 organic acid compound are mixed at a mass ratio of 1:1:1 under normal pressure. First, the chloropropenol compound is slowly added dropwise to the organic amine compound at 100°C. The temperature is raised to 80°C at a rate of 1°C / min and maintained for 3 hours. The organic acid is then added for esterification. The temperature is maintained at 110°C for 1 hour, then cooled to below 40°C to obtain the modified quaternary ammonium salt.

[0064] The bactericidal corrosion inhibitor is composed of the following components in weight percentage: 60% modified quaternary ammonium salt, 20% imidazoline quaternary ammonium salt, and 20% aqueous solvent. The bactericidal corrosion inhibitor has good water solubility in the test medium, a corrosion rate of 0.083 mm / a, and a bactericidal rate of 97%.

[0065] Example 5

[0066] The modified quaternary ammonium salt is obtained by the following process: a C1-C14 organic amine compound, a 3-chloropropenol compound, and a C1-C3 organic acid compound are mixed at a mass ratio of 1:1:1 under normal pressure. First, the chloropropenol compound is slowly added dropwise to the organic amine compound at 40°C. The temperature is raised to 80°C at a rate of 2°C / min and maintained for 3 hours. Then, the organic acid is added for esterification. After maintaining the temperature at 80°C for 1 hour, the temperature is lowered to below 40°C to obtain the modified quaternary ammonium salt.

[0067] The bactericidal corrosion inhibitor consists of the following components by weight: 60% modified quaternary ammonium salt, 20% imidazoline quaternary ammonium salt, and 20% aqueous solvent. The bactericidal corrosion inhibitor exhibits good water solubility in the test medium, resulting in a corrosion rate of 0.065 mm / a and a bactericidal efficiency of 95%. Compared to Examples 1 to 4, the corrosion rate significantly decreased, primarily due to the rapid temperature increase, which accelerated the neutralization reaction, increased the synthesis rate of the modified quaternary ammonium salt, and reduced the impact of bacteria on corrosion during the corrosion evaluation test.

[0068] Example 6

[0069] The modified quaternary ammonium salt is obtained by the following process: a C1-C14 organic amine compound, a 3-chloropropenol compound, and a C1-C3 organic acid compound are mixed at a mass ratio of 1:1:1 under normal pressure. First, the chloropropenol compound is slowly added dropwise to the organic amine compound at 40°C. The temperature is raised to 80°C at a rate of 2°C / min and maintained for 2 hours. The organic acid is then added for esterification. After maintaining the temperature at 80°C for 1 hour, the temperature is lowered to below 40°C to obtain the modified quaternary ammonium salt.

[0070] The bactericidal corrosion inhibitor consists of the following components by weight: 70% modified quaternary ammonium salt, 20% imidazoline quaternary ammonium salt, and 10% aqueous solvent. The bactericidal corrosion inhibitor exhibited good water solubility in the test medium, a corrosion rate of 0.051 mm / a, and a bactericidal efficiency of 100%. Compared with Example 5, the decreased corrosion rate and increased bactericidal efficiency were primarily due to the reduced proportion of aqueous solvent and the increased proportion of modified quaternary ammonium salt, which enhanced the bactericidal and corrosion-inhibiting effects of the bactericidal corrosion inhibitor.

[0071] Example 7

[0072] The modified quaternary ammonium salt is obtained by the following process: a C1-C14 organic amine compound, a 3-chloropropenol compound, and a C1-C3 organic acid compound are mixed at a mass ratio of 1:1:1 under normal pressure. First, the chloropropenol compound is slowly added dropwise to the organic amine compound at 40°C. The temperature is raised to 80°C at a rate of 2°C / min and maintained for 2 hours. The organic acid is then added for esterification. After maintaining the temperature at 80°C for 1 hour, the temperature is lowered to below 40°C to obtain the modified quaternary ammonium salt.

[0073] The bactericidal corrosion inhibitor is composed of the following components in weight percentage: 70% modified quaternary ammonium salt, 10% imidazoline quaternary ammonium salt, and 20% aqueous solvent. The bactericidal corrosion inhibitor has good water solubility in the test medium, a corrosion rate of 0.057 mm / a, and a bactericidal rate of 100%.

[0074] Compared with Example 6, the results did not change significantly because the main factor affecting corrosion in the corrosion evaluation test comes from bacteria, and the modified quaternary ammonium salt has a relatively good control over the bacteria. Therefore, even if the contents of the latter two change, it will not have much impact on the results.

[0075] Example 8

[0076] The modified quaternary ammonium salt is obtained by the following process: a C1-C14 organic amine compound, a 3-chloropropenol compound, and a C1-C3 organic acid compound are mixed at a mass ratio of 1:1:1 under normal pressure. First, the chloropropenol compound is slowly added dropwise to the organic amine compound at 40°C. The temperature is raised to 110°C at a rate of 2°C / min and maintained for 2 hours. The organic acid is then added for esterification. The temperature is maintained at 80°C for 1 hour, then cooled to below 40°C to obtain the modified quaternary ammonium salt.

[0077] The bactericidal corrosion inhibitor is composed of the following components by weight: 60% modified quaternary ammonium salt, 20% imidazoline sebacic acid salt, and 20% aqueous solvent. The bactericidal corrosion inhibitor has good water solubility in the test medium, a corrosion rate of 0.094 mm / a, and a bactericidal rate of 95%.

[0078] Example 9

[0079] The modified quaternary ammonium salt is obtained by the following process: a C1-C14 organic amine compound, a 3-chloropropenol compound, and a C1-C3 organic acid compound are mixed at a mass ratio of 1:1:1 under normal pressure. First, the chloropropenol compound is slowly added dropwise to the organic amine compound at 40°C. The temperature is raised to 110°C at a rate of 2°C / min and maintained for 1 hour. The organic acid is then added for esterification. After maintaining the temperature at 40°C for 1 hour, the temperature is lowered to below 40°C to obtain the modified quaternary ammonium salt.

[0080] The bactericidal corrosion inhibitor is composed of the following components by weight: 60% modified quaternary ammonium salt, 20% imidazoline sebacate, and 20% aqueous solvent. The bactericidal corrosion inhibitor exhibits good water solubility in the test medium, with a corrosion rate of 0.101 mm / a and a bactericidal efficiency of 95%. The increased corrosion rate is primarily due to the replacement of the imidazoline quaternary ammonium salt with imidazoline sebacate, rendering this component sterile. Furthermore, the high neutralization temperature during the preparation of the modified quaternary ammonium salt hinders its synthesis. Consequently, the overall bactericidal and corrosion-inhibiting properties of the bactericidal corrosion inhibitor are reduced.

[0081] Example 10

[0082] The modified quaternary ammonium salt is obtained by the following process: a C1-C14 organic amine compound, a 3-chloropropenol compound, and a C1-C3 organic acid compound are mixed at a mass ratio of 1:1:1 under normal pressure. First, the chloropropenol compound is slowly added dropwise to the organic amine compound at 40°C. The temperature is raised to 80°C at a rate of 2°C / min and maintained for 1 hour. The organic acid is then added for esterification. After maintaining the temperature at 80°C for 1 hour, the temperature is lowered to below 40°C to obtain the modified quaternary ammonium salt.

[0083] The bactericidal corrosion inhibitor is composed of the following components by weight: 60% modified quaternary ammonium salt, 20% imidazoline sebacic acid salt, and 20% aqueous solvent. The bactericidal corrosion inhibitor has good water solubility in the test medium, a corrosion rate of 0.086 mm / a, and a bactericidal rate of 95%.

[0084] Example 11

[0085] The modified quaternary ammonium salt is obtained by the following process: a C1-C14 organic amine compound, a 3-chloropropenol compound, and a C1-C3 organic acid compound are mixed at a mass ratio of 1:1:1 under normal pressure. First, the chloropropenol compound is slowly added dropwise to the organic amine compound at 40°C. The temperature is raised to 80°C at a rate of 2°C / min and maintained for 2 hours. The organic acid is then added for esterification. After maintaining the temperature at 80°C for 1 hour, the temperature is lowered to below 40°C to obtain the modified quaternary ammonium salt.

[0086] The bactericidal corrosion inhibitor is composed of the following components by weight: 70% modified quaternary ammonium salt, 20% imidazoline quaternary ammonium salt, and 10% aqueous solvent. The bactericidal corrosion inhibitor exhibited good water solubility in the test medium, a corrosion rate of 0.051 mm / year, and a bactericidal efficiency of 100%. Its performance was superior to that of the imidazoline-based corrosion inhibitor KEW-227 (corrosion rate of 0.078 mm / year) and the quaternary ammonium salt bactericide 1227 (bactericidal efficiency of 90%).

[0087] Example 12

[0088] The modified quaternary ammonium salt is obtained by the following process: a C1-C14 organic amine compound, a 3-chloropropenol compound, and a C1-C3 organic acid compound are mixed at a mass ratio of 1:1:1 under normal pressure. First, the chloropropenol compound is slowly added dropwise to the organic amine compound at 40°C. The temperature is raised to 80°C at a rate of 2°C / min and maintained for 2 hours. The organic acid is then added for esterification. After maintaining the temperature at 80°C for 1 hour, the temperature is lowered to below 40°C to obtain the modified quaternary ammonium salt.

[0089] The bactericidal corrosion inhibitor is composed of the following components by weight: 70% modified quaternary ammonium salt, 20% imidazoline quaternary ammonium salt, and 10% aqueous solvent. The bactericidal corrosion inhibitor exhibited good water solubility in the test medium, a corrosion rate of 0.051 mm / year, and a bactericidal efficiency of 100%. Its performance was superior to that of the imidazoline-based corrosion inhibitor KY-5 (corrosion rate of 0.072 mm / year) and the bactericide KEW-538 (bactericidal efficiency of 90%).

[0090] Example 13

[0091] The modified quaternary ammonium salt is obtained by the following process: a C1-C14 organic amine compound, a 3-chloropropenol compound, and a C1-C3 organic acid compound are mixed at a mass ratio of 1:1:1 under normal pressure. First, the chloropropenol compound is slowly added dropwise to the organic amine compound at 40°C. The temperature is raised to 80°C at a rate of 2°C / min and maintained for 2 hours. The organic acid is then added for esterification. After maintaining the temperature at 80°C for 1 hour, the temperature is lowered to below 40°C to obtain the modified quaternary ammonium salt.

[0092] The bactericidal corrosion inhibitor is composed of the following components in weight percentage: 50% modified quaternary ammonium salt, 20% imidazoline quaternary ammonium salt, and 30% aqueous solvent. The bactericidal corrosion inhibitor has good water solubility in the test medium, a corrosion rate of 0.122 mm / a, and a bactericidal rate of 90%.

[0093] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A modified quaternary ammonium salt, characterized in that The modified quaternary ammonium salt is: wherein R1 and R3 are H, -CH3, -C2H5, -OH, -C3H7 or -C2H4OH; R2 is -CH3; R4 is -CH3, -C2H5 or -H; X is Cl.

2. A method for preparing a modified quaternary ammonium salt as claimed in claim 1, characterized in that, The method comprises: At a specified temperature, add chloropropylene compounds to the organic amine compounds and keep them warm. reaction; Then, organic acids are added to carry out esterification and the reaction is carried out at a temperature-insulating state; After esterification, the temperature is lowered to below 40°C to terminate the reaction; The chloropropylene compound is 3-chloropropylene alcohol; The structure of the organic amine compound is shown below: The organic acid structure is shown below: wherein R1-R4 are consistent with those in claim 1.

3. The preparation method of modified quaternary ammonium salt according to claim 2, wherein The organic amine compound, the chloropropylene compound and the organic acid are mixed at a mass ratio of 1:1:1 under normal pressure. Perform the synthesis reaction.

4. The preparation method of modified quaternary ammonium salt according to claim 2, wherein The step of adding the chloropropylene compound dropwise to the organic amine compound at a specified temperature to carry out the heat preservation reaction specifically comprises: Control the temperature to rise to 20~100℃ at a rate of 1~2℃ / min; At a specified temperature of 20-100°C, add a chlorinated allyl compound dropwise to the organic amine compound; Control the temperature between 40 and 110°C and keep it warm for 1 to 3 hours.

5. The preparation method of modified quaternary ammonium salt according to claim 2, wherein The organic acid is then added for esterification and the heat preservation reaction is carried out. The heat preservation reaction specifically refers to: controlling the temperature within the temperature range of 40° C. to 110° C. and keeping the temperature for 1 hour.

6. according to the preparation method of the arbitrary described modified quaternary ammonium salt of claim 4 or 5, it is characterized in that, During the heat preservation reaction, the temperature is raised to 40-110° C. at a rate of 1-2° C. / min.

7. A corrosion inhibitor comprising the modified quaternary ammonium salt according to claim 1, characterized in that The corrosion inhibitor comprises, calculated by mass percentage, 60-70% of a modified quaternary ammonium salt, 10-30% of an imidazoline derivative, and 10-30% of a water solvent.

8. The corrosion inhibitor comprising a modified quaternary ammonium salt according to claim 7, wherein The corrosion inhibitor comprises, calculated by mass percentage, 60-70% of a modified quaternary ammonium salt, 10-20% of an imidazoline derivative, and 20-30% of a water solvent.

9. The corrosion inhibitor comprising a modified quaternary ammonium salt according to claim 7, wherein The corrosion inhibitor comprises, calculated by mass percentage, 60-70% of a modified quaternary ammonium salt, 20-30% of an imidazoline derivative, and 10-20% of a water solvent.

10. The corrosion inhibitor comprising a modified quaternary ammonium salt according to any one of claims 7 to 9, characterized in that: The imidazoline derivative is imidazoline quaternary ammonium salt or imidazoline sebacic acid salt or oleic acid salt or a mixture of oleic acid salt and dimer acid salt.

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