Oil-soluble composite corrosion inhibitor as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of corrosion inhibition of electronic devices, and discloses an oil-soluble composite corrosion inhibitor as well as a preparation method and application thereof. The composite corrosion inhibitor comprises the following components in parts by weight: 5-10 parts of bis-Schiff base, 3-5 parts of a benzotriazole derivative and 80-90 parts of solvent oil, and the bis-Schiff base is prepared by condensing an aldehyde compound, an amine compound and an imidazoline compound. The benzotriazole derivative is matched with the bis-Schiff base, so that a firm metal protective film can be formed when the metal protective film is combined with a metal surface; the hydrophilic polar group of the bis-Schiff base is combined with the metal surface, the oleophylic group of the bis-Schiff base is combined with the solvent oil, the action of a corrosion medium and the metal surface is blocked, the solvent oil serves as a diluent to fully dilute and disperse the bis-Schiff base and the benzotriazole derivative, and the anti-corrosion effect of the corrosion inhibitor is further enhanced. The oil-soluble composite corrosion inhibitor provided by the invention is firm in film formation, excellent in corrosion inhibition performance, good in stability and environment-friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic device corrosion inhibition, and particularly relates to an oil-soluble composite corrosion inhibitor and a preparation method and application thereof. Background Art

[0002] Metal corrosion refers to the damage or deterioration of metals caused by chemical, electrochemical reactions and physical dissolution in the environment. Thermodynamic studies have shown that most metals have a tendency to transform into an oxidized ion state by interacting with the surrounding environment, which means that metal corrosion is a spontaneous process. Corrosion occurs on the surface of metals and usually comes into contact with the gas phase or liquid phase. The protective effect on metals determines how valuable they are in practical applications. In some specific environments, metals will be passivated, and the passivation effect can just inhibit the reaction on the metal surface, which can protect the metal. However, in other environments, the metal surface is not passivated, so some measures must be taken to protect the metal. Copper and its alloys, as an extremely important metal material, are widely used in various fields such as electronics, communications, electrical engineering, machinery manufacturing, construction and defense industry. At present, the demand and use of copper products in various industries in my country are still increasing, which fully demonstrates that the use and development of copper and its alloy materials have good prospects. At the same time, the corrosion of copper products during processing, production, transportation and use has attracted much attention, especially in island areas with high temperatures, humidity and salinity, because this corrosion has great damage to the metal itself and can directly affect the performance of the material, and the quality of the material performance is related to the use range and service life of the metal material. When the protection mechanism is not taken seriously or the protection mechanism is damaged, the metal will undergo corrosion reaction, making the metal material more vulnerable to damage.

[0003] Currently, many methods have been developed to prevent metal corrosion. Among these methods, corrosion inhibitor technology is one of the most suitable strategies for anti-corrosion of island transformer stations. Only a small amount of corrosion inhibitor is needed to achieve a good corrosion inhibition effect. In most interactions between metals and corrosion inhibitors, the adsorption of corrosion inhibitors occurs first as physical adsorption, followed by chemical adsorption. By slowing down or even preventing metals from being damaged by corrosion, the use of corrosion inhibitors can enable equipment to operate safely, slow down the rate of metal material loss, and have significant economic benefits. However, the existing petroleum barium sulfonate corrosion inhibitors have insufficient thermal stability and film-forming reliability, limited anti-corrosion effect, and great harm to the environment. Summary of the invention

[0004] The purpose of the present invention is to provide an oil-soluble composite corrosion inhibitor and a preparation method and application thereof, wherein a bis-Schiff base is matched with a benzotriazole derivative and a solvent oil to prepare an oil-soluble corrosion inhibitor with better performance; wherein the benzotriazole derivative is matched with the bis-Schiff base, and when combined with the metal surface, a firm metal protective film with good stability and excellent corrosion inhibition performance can be formed; in addition, the hydrophilic polar group of the bis-Schiff base is combined with the metal surface, while the lipophilic group thereof is combined with the solvent oil to block the action of the corrosive medium and the metal surface, and the solvent oil is used as a diluent to fully dilute and disperse the bis-Schiff base and the benzotriazole derivative, thereby further enhancing the anti-corrosion effect of the corrosion inhibitor, and providing an oil-soluble composite corrosion inhibitor with firm film formation, excellent corrosion inhibition performance, good stability and environmental protection.

[0005] In order to achieve the above purpose, the technical solution adopted in this application is:

[0006] The first object of the present invention is to provide an oil-soluble composite corrosion inhibitor, which is prepared by comprising the following components, in parts by weight: 5 to 10 parts of a bis-Schiff base, 3 to 5 parts of a benzotriazole derivative and 80 to 90 parts of solvent oil, wherein the bis-Schiff base is prepared by condensation of an aldehyde compound, an amine compound and an imidazoline compound.

[0007] Furthermore, the preparation method of the bis-Schiff base comprises the following steps: mixing an aldehyde compound and an amine compound, stirring at 75°C to 85°C under normal pressure for 10min to 20min, adjusting the pressure to 0.05Mpa to 0.1Mpa, adding an acid auxiliary agent, an alcohol auxiliary agent and an imidazoline compound, reacting at a constant temperature of 80°C to 100°C for 4h to 6h, removing the alcohol auxiliary agent and drying to obtain the bis-Schiff base.

[0008] Furthermore, the weight ratio of the aldehyde compound to the amine compound is 0.9-1.1:0.9-1.1, the aldehyde compound is formaldehyde or glutaraldehyde, and the amine compound is dodecylamine or octadecylamine.

[0009] Furthermore, the molar ratio of the imidazoline compound to the aldehyde compound is 1-1.2:1-1.2, and the imidazoline compound is heptadecenylaminoethyl imidazoline or heptadecenylhydroxyethyl imidazoline.

[0010] Furthermore, the molar ratio of the acid auxiliary agent to the amine compound is 1-1.2:1-1.2, the molar ratio of the alcohol auxiliary agent to the amine compound is 1:0.1-0.15, the acid auxiliary agent is formic acid or acetic acid, and the alcohol auxiliary agent is ethanol or ethylene glycol.

[0011] Furthermore, the synthesis method of the benzotriazole derivative comprises the following steps: after mixing lauric acid, benzotriazole and solvent oil, grafting reaction is carried out at 150° C. to 170° C. for 7.5 h to 8.5 h to obtain the benzotriazole derivative. The benzotriazole derivative has the following structure:

[0012]

[0013] Furthermore, the molar volume ratio of the lauric acid, benzotriazole and solvent oil is 0.1 mol to 0.12 mol: 0.1 mol to 0.15 mol: 190 ml to 220 ml.

[0014] Furthermore, the solvent oil is transformer oil, and the density of the transformer oil is 0.8 g / cm 3 ~1.0g / cm 3 .

[0015] The second object of the present invention is to provide a method for preparing the above-mentioned oil-soluble composite corrosion inhibitor, comprising the following steps: weighing each component according to weight percentage; mixing the bis-Schiff base, benzotriazole derivative and solvent oil, and stirring and mixing at 50°C to 70°C to obtain the oil-soluble corrosion inhibitor.

[0016] The third object of the present invention is to provide the application of the above oil-soluble composite corrosion inhibitor in the corrosion protection of electronic devices in island areas.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The oil-soluble composite corrosion inhibitor provided by the present invention is prepared by combining a bis-Schiff base with a benzotriazole derivative and a solvent oil to prepare an oil-soluble corrosion inhibitor with better performance; wherein, the bis-Schiff base has more adsorption sites and is easier to form an adsorption film with stronger adsorption capacity with the metal, and the benzotriazole derivative is matched with the bis-Schiff base, and when combined with the metal surface, it can form a firm metal protective film with good stability and excellent corrosion inhibition performance; in addition, the hydrophilic polar group of the bis-Schiff base is combined with the metal surface, and its lipophilic group is combined with the solvent oil to block the effect of the corrosive medium and the metal surface, and the solvent oil is used as a diluent to fully dilute and disperse the bis-Schiff base and the benzotriazole derivative, thereby further enhancing the anti-corrosion effect of the corrosion inhibitor. In addition, the raw materials of the oil-soluble corrosion inhibitor of the present invention are natural, and it is an environmentally friendly corrosion inhibitor.

[0019] (2) The oil-soluble corrosion inhibitor prepared by the present invention has a corrosion inhibition rate of 98.73% in a 100°C static coupon weight loss test and a corrosion inhibition rate of 96.35% in a salt spray test. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the infrared spectrum of the Mannich base prepared in Example 1 of the present invention.

[0021] Figure 2 This is an AFM image of the oil-soluble composite corrosion inhibitor of Example 1 of the present invention.

[0022] Figure 3 This is an AFM image of the oil-soluble composite corrosion inhibitor of Example 2 of the present invention.

[0023] Figure 4 This is an AFM image of the oil-soluble composite corrosion inhibitor of Example 3 of the present invention.

[0024] Figure 5 This is an AFM image of the oil-soluble composite corrosion inhibitor of Example 4 of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 creative work are within the scope of protection of the present invention.

[0026] It should be noted that the professional terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the various raw materials, reagents, instruments and equipment used in the following embodiments of the present invention can be purchased from the market or prepared by existing methods. The transformer oil used in the present invention is purchased from Shanghai Mojiezuo Chemical Co., Ltd., specifically 25 # Transformer oil.

[0027] Aiming at the problems that the existing petroleum barium sulfonate corrosion inhibitor has insufficient thermal stability and film-forming reliability, is a by-product, has poor stability, has limited anti-corrosion effect, and has great harm to the environment, the present invention provides an oil-soluble composite corrosion inhibitor, which is prepared by comprising the following components in parts by weight: 5 to 10 parts of a bis-Schiff base, 3 to 5 parts of a benzotriazole derivative and 80 to 90 parts of solvent oil, wherein the bis-Schiff base is prepared by condensing an aldehyde compound, an amine compound and an imidazoline compound.

[0028] The oil-soluble composite corrosion inhibitor provided by the present invention is prepared by combining a bis-Schiff base with a benzotriazole derivative and a solvent oil to prepare an oil-soluble corrosion inhibitor with better performance; wherein the benzotriazole derivative is matched with the bis-Schiff base, and when combined with the metal surface, a firm metal protective film can be formed, which has good stability and excellent corrosion inhibition performance; in addition, the hydrophilic polar group of the bis-Schiff base is combined with the metal surface, and the lipophilic group thereof is combined with the solvent oil to block the effect of the corrosive medium and the metal surface, and the solvent oil is used as a diluent to fully dilute and disperse the bis-Schiff base and the benzotriazole derivative, thereby further enhancing the anti-corrosion effect of the corrosion inhibitor. In addition, the raw materials of the oil-soluble corrosion inhibitor of the present invention are natural, and it is an environmentally friendly corrosion inhibitor.

[0029] In some preferred embodiments, the preparation method of the bis-Schiff base comprises the following steps: mixing an aldehyde compound with an amine compound, stirring at 75°C to 85°C under normal pressure for 10min to 20min, adjusting the pressure to 0.05Mpa to 0.1Mpa, adding an acid auxiliary agent, an alcohol auxiliary agent and an imidazoline compound, reacting at 80 to 100°C for 4h to 6h, removing the alcohol auxiliary agent and drying to obtain the bis-Schiff base. The preparation process of the bis-Schiff base used in the present invention is simple, environmentally friendly, and the raw materials are easily available. The prepared bis-Schiff base has many adsorption sites and strong adsorption capacity, and has multiple adsorption groups such as amino groups and imidazole rings.

[0030] In some preferred embodiments, the weight ratio of the aldehyde compound to the amine compound is 0.9-1.1:0.9-1.1, the aldehyde compound is formaldehyde or glutaraldehyde, and the amine compound is dodecylamine or octadecylamine. The aldehyde compound used in the present invention provides an aldehyde group for the synthesis of Schiff base. Dodecylamine and octadecylamine have certain corrosion inhibition properties. The corrosion inhibition property of the double Schiff base is further enhanced by the synthesis of dodecylamine or octadecylamine.

[0031] In some preferred embodiments, the molar ratio of the imidazoline compound to the aldehyde compound is 1-1.2:1-1.2, and the imidazoline compound is heptadecaenylaminoethyl imidazoline or heptadecaenylhydroxyethyl imidazoline. The heptadecaenylaminoethyl imidazoline or heptadecaenylhydroxyethyl imidazoline used in the present invention provides an imidazole ring for the synthesized corrosion inhibitor, thereby increasing the adsorption capacity.

[0032] In some preferred embodiments, the molar ratio of the acid auxiliary agent to the amine compound is 1-1.2:1-1.2, the molar ratio of the alcohol auxiliary agent to the amine compound is 1:0.1-0.15, the acid auxiliary agent is formic acid or acetic acid, and the alcohol auxiliary agent is ethanol or ethylene glycol.

[0033] In some preferred embodiments, the method for synthesizing benzotriazole derivatives comprises the following steps: mixing lauric acid, benzotriazole and solvent oil, and subjecting the mixture to a grafting reaction at 150° C. to 170° C. for 7.5 h to 8.5 h to obtain a benzotriazole derivative.

[0034] The benzotriazole derivative has the following structure:

[0035]

[0036] In some preferred embodiments, the molar volume ratio of lauric acid, benzotriazole and transformer oil is 0.1 mol-0.12 mol: 0.1 mol-0.15 mol: 190 ml-220 ml.

[0037] In some preferred embodiments, the solvent oil is transformer oil, and the density of the transformer oil is 0.8 g / cm 3 ~1.0g / cm 3 .

[0038] The preparation method of the oil-soluble composite corrosion inhibitor comprises the following steps: weighing each component according to weight percentage; mixing the bis-Schiff base, benzotriazole derivative and solvent oil, and stirring and mixing at 50-70° C. to obtain the oil-soluble corrosion inhibitor.

[0039] The application of the above oil-soluble composite corrosion inhibitor in the anti-corrosion of electronic devices in island areas is as follows: rust-proof oil is prepared with transformer oil as the base oil, and 3wt% of the composite corrosion inhibitor is added to a transformer station on an island, once every 24 hours, and its corrosion inhibition efficiency is increased by more than 90%.

[0040] The following is further explained through specific implementation.

[0041] Example 1

[0042] An oil-soluble composite corrosion inhibitor, the composite corrosion inhibitor comprises the following components by weight: 10 parts of bis-Schiff base, 5 parts of benzotriazole derivatives and 80 parts of transformer oil, wherein the density of the transformer oil is 0.8 g / cm 3 ~1g / cm 3 .

[0043] The preparation method of the bis-Schiff base comprises the following steps: mixing glutaraldehyde and octadecylamine at a molar ratio of 1.0:0.9, stirring at 30°C and normal pressure for 10 minutes, adjusting the pressure to 0.1Mp, adding formic acid, ethanol and heptadecanylamine ethyl imidazoline, wherein the molar ratio of formic acid to octadecylamine is 1:1, the molar ratio of ethanol to octadecylamine is 1:0.1, and the molar ratio of heptadecanylamine ethyl imidazoline to glutaraldehyde is 1:1, reacting at a constant temperature of 100°C for 4 hours, removing ethanol and drying to obtain the bis-Schiff base.

[0044] The method for synthesizing benzotriazole derivatives comprises the following steps: adding 0.1 mol of lauric acid and 0.12 mol of benzotriazole into a three-necked round-bottom flask, adding 200 ml of transformer oil, and then heating at 160° C. for 8 hours to obtain the benzotriazole derivatives.

[0045] The preparation method of the oil-soluble composite corrosion inhibitor comprises the following steps:

[0046] Weigh 10 parts of bis-Schiff base, 5 parts of benzotriazole derivative and 80 parts of transformer oil according to the weight ratio, mix the bis-Schiff base, benzotriazole derivative and transformer oil, and stir at 70° C. for 1 hour to obtain an oil-soluble composite corrosion inhibitor.

[0047] Example 2

[0048] An oil-soluble composite corrosion inhibitor, the composite corrosion inhibitor comprises the following components in parts by weight: 5 parts of bis-Schiff base, 5 parts of benzotriazole derivatives and 80 parts of transformer oil, wherein the density of the transformer oil is 0.8 g / cm 3 ~1g / cm 3 .

[0049] The preparation method of the bis-Schiff base comprises the following steps: mixing glutaraldehyde and dodecylamine at a molar ratio of 1.1:0.9, stirring at 25°C and normal pressure for 10 minutes, adjusting the pressure to 0.1Mp, adding acetic acid, ethanol and heptadecanedilamine ethyl imidazoline, wherein the molar ratio of acetic acid to dodecylamine is 1:1, the molar ratio of ethanol to dodecylamine is 1:0.1, and the molar ratio of heptadecanedilamine ethyl imidazoline to glutaraldehyde is 1:1, reacting at a constant temperature of 90°C for 4 hours, removing ethanol and drying to obtain the bis-Schiff base.

[0050] The method for synthesizing benzotriazole derivatives comprises the following steps: adding 0.1 mol of lauric acid and 0.12 mol of benzotriazole into a three-necked round-bottom flask, adding 200 ml of transformer oil, and then heating at 160° C. for 8 hours to obtain the benzotriazole derivatives.

[0051] The preparation method of the oil-soluble composite corrosion inhibitor comprises the following steps:

[0052] Weigh 5 parts of bis-Schiff base, 5 parts of benzotriazole derivative and 80 parts of transformer oil according to the weight ratio, mix the bis-Schiff base, benzotriazole derivative and transformer oil, and stir at 60° C. for 2 hours to obtain an oil-soluble composite corrosion inhibitor.

[0053] Example 3

[0054] An oil-soluble composite corrosion inhibitor, the composite corrosion inhibitor comprises the following components by weight: 5 parts of bis-Schiff base, 3 parts of benzotriazole derivatives and 90 parts of transformer oil, wherein the density of the transformer oil is 0.8 g / cm 3 ~1g / cm 3 .

[0055] The preparation method of the bis-Schiff base comprises the following steps: mixing glutaraldehyde and dodecylamine at a molar ratio of 0.9:1.1, stirring at 30°C and normal pressure for 15 minutes, adjusting the pressure to 0.1Mp, adding formic acid, ethylene glycol and heptadecanedilamine ethyl imidazoline, wherein the molar ratio of formic acid to dodecylamine is 1:1, the molar ratio of ethylene glycol to dodecylamine is 1:0.1, and the molar ratio of heptadecanedilamine ethyl imidazoline to glutaraldehyde is 1:1, reacting at a constant temperature of 90°C for 4 hours, removing ethylene glycol and drying to obtain the bis-Schiff base.

[0056] The method for synthesizing benzotriazole derivatives comprises the following steps: adding 0.1 mol of lauric acid and 0.12 mol of benzotriazole into a three-necked round-bottom flask, adding 200 ml of transformer oil, and then heating at 160° C. for 8 hours to obtain the benzotriazole derivatives.

[0057] The preparation method of the oil-soluble composite corrosion inhibitor comprises the following steps:

[0058] Weigh 5 parts of bis-Schiff base, 3 parts of benzotriazole derivative and 90 parts of transformer oil according to the weight ratio, mix the bis-Schiff base, benzotriazole derivative and transformer oil, and stir at 70° C. for 1 hour to obtain an oil-soluble composite corrosion inhibitor.

[0059] Example 4

[0060] An oil-soluble composite corrosion inhibitor, the composite corrosion inhibitor comprises the following components in parts by weight: 8 parts of bis-Schiff base, 4 parts of benzotriazole derivatives and 85 parts of transformer oil, wherein the density of the transformer oil is 0.8 g / cm 3 ~1g / cm 3 .

[0061] The preparation method of the bis-Schiff base comprises the following steps: mixing glutaraldehyde and dodecylamine in a molar ratio of 1:1, stirring at 30°C and normal pressure for 15 minutes, adjusting the pressure to 0.1Mp, adding acetic acid, ethanol and heptadecanedilamine ethyl imidazoline, wherein the molar ratio of acetic acid to dodecylamine is 1:1, the molar ratio of ethanol to dodecylamine is 1:0.1, and the molar ratio of heptadecanedilamine ethyl imidazoline to glutaraldehyde is 1:1, reacting at a constant temperature of 90°C for 4 hours, removing alcohol auxiliary agents and drying to obtain the bis-Schiff base.

[0062] The method for synthesizing benzotriazole derivatives comprises the following steps: adding 0.1 mol of lauric acid and 0.12 mol of benzotriazole into a three-necked round-bottom flask, adding 200 ml of transformer oil, and then heating at 160° C. for 8 hours to obtain the benzotriazole derivatives.

[0063] The preparation method of the oil-soluble composite corrosion inhibitor comprises the following steps:

[0064] Weigh 8 parts of bis-Schiff base, 4 parts of benzotriazole derivative and 85 parts of transformer oil according to the weight ratio, mix the bis-Schiff base, benzotriazole derivative and transformer oil, and stir at 65° C. for 1.5 hours to obtain an oil-soluble composite corrosion inhibitor.

[0065] In order to further illustrate the technical effect of the present invention, the present invention also provides a comparative example, which is as follows:

[0066] Comparative Example 1

[0067] An oil-soluble composite corrosion inhibitor, which differs from Example 1 in that no benzotriazole derivative is added, and the composite corrosion inhibitor comprises the following components by weight: 10 parts of bis-Schiff base and 80 parts of transformer oil, wherein the density of the transformer oil is 0.8 g / cm 3 ~1g / cm 3 .

[0068] The preparation method of the bis-Schiff base comprises the following steps: mixing glutaraldehyde and octadecylamine at a molar ratio of 1.0:0.9, stirring at 30°C and normal pressure for 10 minutes, adjusting the pressure to 0.1Mp, adding formic acid, ethanol and heptadecanylamine ethyl imidazoline, wherein the molar ratio of formic acid to octadecylamine is 1:1, the molar ratio of ethanol to octadecylamine is 1:0.1, and the molar ratio of heptadecanylamine ethyl imidazoline to glutaraldehyde is 1:1, reacting at a constant temperature of 100°C for 4 hours, removing ethanol and drying to obtain the bis-Schiff base.

[0069] The preparation method of the oil-soluble composite corrosion inhibitor comprises the following steps:

[0070] Weigh 10 parts of bis-Schiff base and 80 parts of transformer oil according to the weight ratio, mix the bis-Schiff base and the transformer oil, and stir at 70° C. for 1 hour to obtain an oil-soluble composite corrosion inhibitor.

[0071] Comparative Example 2

[0072] An oil-soluble composite corrosion inhibitor, which differs from Example 1 in that no bis-Schiff base is added, and the composite corrosion inhibitor comprises the following components in parts by weight: 5 parts of benzotriazole derivatives and 80 parts of transformer oil, wherein the density of the transformer oil is 0.8 g / cm 3 ~1g / cm 3 .

[0073] The method for synthesizing benzotriazole derivatives comprises the following steps: adding 0.1 mol of lauric acid and 0.12 mol of benzotriazole into a three-necked round-bottom flask, adding 200 ml of transformer oil, and then heating at 160° C. for 8 hours to obtain the benzotriazole derivatives.

[0074] The preparation method of the oil-soluble composite corrosion inhibitor comprises the following steps:

[0075] Weigh 5 parts of benzotriazole derivative and 80 parts of transformer oil according to the weight ratio, mix the benzotriazole derivative and the transformer oil, and stir at 70° C. for 1 hour to obtain an oil-soluble composite corrosion inhibitor.

[0076] The oil-soluble composite corrosion inhibitors obtained in Examples 1 to 4 and Comparative Examples 1 to 2 were subjected to the following performance tests. The results are as follows: Figure 1-Figure 3 As shown in Tables 1 and 2.

[0077] 1. Infrared test

[0078] Figure 1 This is the infrared spectrum of the Mannich base of Example 1 of the present invention. Figure 1 As shown, the rocking vibration of the CH2 plane is at 720 cm -1 The CN stretching vibration of the imidazole ring is at 1344 cm -1 Nearby, CN stretching vibration at 1372cm -1 Nearby, CH3 angle vibration at 1466cm -1 Nearby, the C=N vibration peak of the imidazole ring is at 1636cm -1 Nearby, the long chain C=N vibration peak is at 1647cm -1 Nearby. CH2 symmetric stretching vibration at 2852cm -1 Nearby, CH2 antisymmetric stretching vibration at 2920cm -1 Nearby, the NH vibration peak is at 3335cm -1 It is considered that the target product has been successfully synthesized.

[0079] 2. AFM test

[0080] Figure 2This is an AFM image of the oil-soluble composite corrosion inhibitor of Example 1 of the present invention. Figure 3 This is an AFM image of the oil-soluble composite corrosion inhibitor of Example 2 of the present invention. Figure 4 This is an AFM image of the oil-soluble composite corrosion inhibitor of Example 3 of the present invention. Figure 5 : is an AFM image of the oil-soluble composite corrosion inhibitor of Example 4 of the present invention. Figure 2-Figure 5 As shown, after the oil-soluble composite corrosion inhibitor prepared by the present invention is used for corrosion inhibition, the average surface roughness and the maximum surface roughness are reduced.

[0081] 3. Physical and chemical properties, corrosion inhibition effect

[0082] The oil-soluble composite corrosion inhibitors of Examples 1 to 4 and Comparative Examples 1 to 2 were tested for their physical and chemical properties and corrosion inhibition effects.

[0083] Among them, the test of weight loss corrosion inhibition rate in salt spray test is as follows: the 10# steel sheet for the experiment is polished step by step according to 400#, 800#, 1200#, 1500#, 2000#, and 3000# sandpaper, then washed three times with anhydrous ethanol and dried with cold air, and the sample mass is weighed by analytical balance, and the average value is obtained by parallel measurement three times. The surfaces other than the measured surface are sealed with silicone rubber, all immersed in the configured anti-rust oil for 1min, slowly pulled and placed in a cool and dry place for 24h, and placed in a salt spray box. The salt spray test is carried out in accordance with GB / T1012-2012, using 5wt.% NaCl solution, and the experiment is carried out according to the required time, using continuous spray. After the salt spray test, take it out, wash it with cleaning oil, wash it with anhydrous ethanol three times, and then dry it with cold air. After stripping off the silicone rubber, weigh it again three times to take the average value.

[0084] Table 1 Physical and chemical properties of oil-soluble composite corrosion inhibitors

[0085]

[0086] Table 1 shows the physical and chemical properties of the oil-soluble composite corrosion inhibitor prepared in Example 1 of the present invention. As shown in Table 1, the oil-soluble composite corrosion inhibitor prepared in the present invention has good solubility.

[0087] Table 2 Corrosion inhibition effect test table of oil-soluble composite corrosion inhibitor

[0088] serial number 100℃ static coupon weight loss test corrosion inhibition rate (%) Salt spray test weight loss corrosion inhibition rate (%) Example 1 97.01 91.42 Example 2 94.44 96.35 Example 3 97.17 88.34 Example 4 90.11 85.47 Comparative Example 1 88.79 82.39 Comparative Example 2 77.01 54.17

[0089] Table 2 is a comparison of the corrosion inhibition performance of the oil-soluble composite corrosion inhibitors of Examples 1 to 4 of the present invention and Comparative Examples 1 to 2. As can be seen from Table 2, the corrosion inhibition performance of the oil-soluble composite corrosion inhibitor prepared by the present invention is good, and the composite corrosion inhibitor has better corrosion inhibition performance than the single corrosion inhibitor and better solubility.

[0090] It should be noted that when the present invention involves a numerical range, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as those in the embodiments, in order to avoid redundancy, the present invention describes a preferred embodiment. Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the attached claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0091] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An oil-soluble composite corrosion inhibitor, characterized in that: The composite corrosion inhibitor is prepared by including the following components in parts by weight: 5 to 10 parts of bis-Schiff base, 3 to 5 parts of benzotriazole derivatives and 80 to 90 parts of solvent oil, wherein the bis-Schiff base is prepared by condensing aldehyde compounds, amine compounds and imidazoline compounds.

2. The oil-soluble composite corrosion inhibitor according to claim 1, characterized in that: The preparation method of the bis-Schiff base comprises the following steps: mixing an aldehyde compound and an amine compound, stirring at 25°C to 30°C at normal pressure for 10min to 20min, adjusting the pressure to 0.05Mpa to 0.1Mpa, adding an acid auxiliary agent, an alcohol auxiliary agent and an imidazoline compound, reacting at a constant temperature of 80°C to 100°C for 4h to 6h, removing the alcohol auxiliary agent and drying to obtain the bis-Schiff base.

3. The oil-soluble composite corrosion inhibitor according to claim 2, characterized in that: The weight ratio of the aldehyde compound to the amine compound is 0.9-1.1:0.9-1.1, the aldehyde compound is formaldehyde or glutaraldehyde, and the amine compound is dodecylamine or octadecylamine.

4. The oil-soluble composite corrosion inhibitor according to claim 2, characterized in that: The molar ratio of the imidazoline compound to the aldehyde compound is 1-1.2:1-1.2, and the imidazoline compound is heptadecenylaminoethyl imidazoline or heptadecenylhydroxyethyl imidazoline.

5. The oil-soluble composite corrosion inhibitor according to claim 2, characterized in that: The molar ratio of the acid auxiliary agent to the amine compound is 1-1.2:1-1.2, the molar ratio of the alcohol auxiliary agent to the amine compound is 1:0.1-0.15, the acid auxiliary agent is formic acid or acetic acid, and the alcohol auxiliary agent is ethanol or ethylene glycol.

6. The oil-soluble composite corrosion inhibitor according to claim 1, characterized in that: The method for synthesizing benzotriazole derivatives comprises the following steps: mixing lauric acid, benzotriazole and solvent oil, and subjecting the mixture to grafting reaction at 150° C. to 170° C. for 7.5 h to 8.5 h to obtain benzotriazole derivatives.

7. The oil-soluble composite corrosion inhibitor according to claim 6, characterized in that: The molar volume ratio of the lauric acid, benzotriazole and solvent oil is 0.1 mol to 0.12 mol: 0.1 mol to 0.15 mol: 190 ml to 220 ml.

8. The oil-soluble composite corrosion inhibitor according to claim 1, characterized in that: The solvent oil is transformer oil, and the density of the transformer oil is 0.8 g / cm 3 ~1.0g / cm 3 .

9. A method for preparing the oil-soluble composite corrosion inhibitor according to claim 1, characterized in that: The following steps are involved: Weigh each component according to weight percentage; mix the bis-Schiff base, benzotriazole derivative and solvent oil, and stir and mix at 50° C. to 70° C. to obtain an oil-soluble corrosion inhibitor.

10. Use of the oil-soluble composite corrosion inhibitor according to claim 1 in the corrosion protection of electronic devices in island areas.

Images