CN106319528A - Corrosion inhibitor composition and application thereof - Google Patents

Abstract

The application discloses a corrosion inhibitor composition. The composition comprises a compound of formula (I) or a salt thereof and a water-soluble polymer. The corrosion inhibitor composition can effectively slow down the corrosion of iron metal and galvanized steel.

Description

A kind of corrosion inhibitor composition and its application

technical field

This application relates to, but is not limited to, the field of corrosion inhibitors.

Background technique

The related art has corrosion inhibitors for inhibiting the corrosion of metals.

There is still a need in the market for additional corrosion inhibitors effective in inhibiting the corrosion of metals, especially ferrous metals and/or galvanized steel.

Contents of the invention

The following is an overview of the topics described in detail in this article. This summary is not intended to limit the scope of the claims.

The inventors of the present application have unexpectedly found in research that, in slowing down the corrosion of ferrous metals and galvanized steel, there is an unexpected synergistic effect between the compound of formula (I) or its salt and the water-soluble polymer, and comprises The above two-component combination is particularly effective for aqueous systems containing suspended solids such as sludge, oxides of metal ions, and the like.

In one aspect, an embodiment of the application provides a corrosion inhibitor composition, the composition comprising a compound of the following formula (I) or a salt thereof and a water-soluble polymer:

Wherein, X represents NH, NR ¹ or O;

R and R are the same or different and are independently selected from C ^1-10 _hydrocarbon groups.

In the above or other embodiments of the present application, "C _1-10 hydrocarbon group" may include substituted or unsubstituted C _1-10 alkyl, C _1-10 alkenyl, C _1-10 alkynyl and aryl, etc., Aryl groups may include, for example, phenyl, benzyl, or other aryl groups, where substituents may be methyl, ethyl, propyl, butyl, methoxy, and the like. For example, C _1-10 hydrocarbyl can be selected from the group consisting of: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, octyl, ethylhexyl , hydroxyethyl, methoxypropyl and 2-methylpropyl.

In the above or other embodiments, in formula (I), X can be NH and R can be C _1-10 alkyl.

In the above or other embodiments, in formula (I), X can be NH and R can be n-butyl, that is, the compound with formula (I) is 2-n-butylamino-3-hydroxysuccinic acid.

In the above or other embodiments, in formula (I), X can be NR ¹ and both R and R ¹ can be C _1-10 alkyl.

In the above or other embodiments, in formula (I), X can be NR ¹ and both R and R ¹ can be methyl, that is, the compound with formula (I) is 2-(N,N-dimethyl ) amino-3-hydroxysuccinic acid.

In the above or other embodiments, the salt of the compound of formula (I) may be an alkali metal or alkaline earth metal salt of the compound of formula (I). For example, the salt of the compound of formula (I) may be one or more salts selected from the group consisting of sodium, potassium, ammonium, calcium or magnesium mono- or di-salts. Optionally, the salt of the compound of formula (I) may be a monosodium or disodium salt of the compound of formula (I), such as 2-n-butylamino-3-hydroxysuccinic acid monosodium salt, 2- n-Butylamino-3-hydroxysuccinic acid disodium salt or 2-(N,N-dimethyl)amino-3-hydroxysuccinic acid disodium salt.

In the above or other embodiments, the compound with formula (I) or its salt can be prepared by the following methods:

(1) prepare cis-epoxysuccinic acid disodium salt (see J.Org.Chem., 1959,24(1), pp54-55), and

(2) Reacting the corresponding ammonia compound or alcohol compound with cis-epoxysuccinic acid disodium salt to obtain the compound of formula (I).

An example of the above preparation is as follows:

(1) Preparation of cis-epoxysuccinic acid disodium salt

(2) Preparation of N-substituted 2-amino-3-hydroxysuccinic acid derivatives

In the present application, the compound of formula (I) or its salt can be prepared by methods similar to the above or methods known or commonly used in the art, or can be obtained commercially.

In the above or other embodiments, the water-soluble polymer may be one or more polymers selected from the group consisting of polymaleic acid, polyacrylic acid, copolymers of acrylic acid and maleic anhydride, and Copolymer of acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid.

Of course, those skilled in the art will understand that the water-soluble polymers used in the present application are not limited to the water-soluble polymers listed above, for example, those polymers commonly used for corrosion inhibition in the art can also be used in this application .

The water-soluble polymer used in the present application can be prepared by methods known or commonly used in the art, or can be obtained commercially.

In the above or other embodiments, the composition may further include one or more additives selected from the group consisting of zinc salts, molybdates, tungstates, tin salts, and silicates.

In the above or other embodiments, the silicate may be water-soluble silicate known or commonly used in the art, such as sodium silicate, calcium silicate and other silicates.

In the above or other embodiments, the zinc salt may be a water-soluble zinc salt known or commonly used in the art, such as zinc chloride, zinc sulfate or zinc nitrate.

In the above or other embodiments, the molybdate may be a water-soluble molybdate known or commonly used in the art, such as sodium molybdate or potassium molybdate.

In the above or other embodiments, the tungstate may be a water-soluble tungstate known or commonly used in the art, such as sodium tungstate or potassium tungstate.

In the above or other embodiments, the tin salt may be a water-soluble tin salt known or commonly used in the art, such as tin chloride.

In the above or other embodiments, in the composition of the present application, the weight ratio between the compound and the water-soluble polymer may be 1:50 to 50:1. Optionally, the weight ratio between the compound and the water-soluble polymer may be 1:5 to 5:1.

In the above or other embodiments, in the composition of the present application, when the composition includes additives, the weight ratio between the compound and the zinc salt can be 1-50:0.1-5, optionally, The weight ratio between the compound and the zinc salt is 5-15:2; the weight ratio between the compound and the molybdate can be 1-50:5-50, the tungstate and The weight ratio between the compounds may be less than or equal to 500:1, the weight ratio between the tin salt and the compound may be less than or equal to 10:1, and/or the compound and the silicic acid The weight ratio between the salts can be 1-50:5-100.

Those skilled in the art will understand that, for the components in the composition of the present application, since some components may be unstable when mixed with other components, the composition of the present application can be obtained by combining all components. The components may be mixed together for formulation, or the components of the compositions of the present application may be separated in separate bags and used only at the same time. For example, all the components of the corrosion inhibitor according to one embodiment of the present application can be directly added to the aqueous solution to be used simultaneously or in any order.

In the above or other embodiments, the composition may exclude phosphorus-containing compounds.

In the above or other embodiments, when the composition is used, the content of the composition is such that in the aqueous solution used, the use concentration of the compound or its salt can be in the range of 1 ppm to 50 ppm by weight, The water-soluble polymer may be used at a concentration in the range of 1 ppm to 50 ppm by weight.

In the above or other embodiments, when the composition contains additives and the composition is used, the content of the composition is such that in the aqueous solution used, the use concentration of the zinc salt can be In the range of 0.1ppm to 5ppm, the use concentration of molybdate can be in the scope of 5ppm to 50ppm by weight, the use concentration of tungstate can be less than or equal to 500ppm by weight, and the use concentration of tin salt can be It is less than or equal to 10 ppm by weight, and the silicate may be used in a concentration in the range of 5 ppm to 100 ppm by weight.

In another aspect, one embodiment of the present application provides the use of the composition as described above as a corrosion inhibitor for inhibiting the corrosion of ferrous metal or galvanized steel. For example, the iron metal may be iron metal in carbon steel.

The inventors of the present application found that the corrosion inhibitor composition in the embodiment of the present application can obtain a synergistic technical effect, and thus exhibit anticorrosion performance superior to general phosphorus-based corrosion inhibitors.

Other aspects will become apparent after reading and understanding the detailed description.

detailed description

Embodiments of the present application are described below through examples, and it should be understood that the embodiments described herein are only used to illustrate and explain the present invention, rather than to limit the present invention.

In the following examples of the present application, all chemical reagents used are commercially available chemical reagents, unless otherwise specified.

In the following examples of the present application, the test method of corrosion rate (or corrosion inhibition effect) is carried out with reference to GB/T 18175-2000 (2000 edition).

Preparation of Example 1 N-substituted 2-amino-3-hydroxysuccinic acid derivatives

N-substituted 2-amino-3-hydroxysuccinic acid derivatives were prepared as follows:

(1) Preparation of cis-epoxysuccinic acid disodium salt

Procedure: Into a 1 liter 5 neck round bottom flask equipped with stirrer, thermometer and reflux tube was added a filtered solution of 116 g (1.0 mole) of maleic acid in 300 mL of distilled water. A solution of sodium hydroxide (60 g, 1.5 moles) in 100 ml of water was added. The heat generated by the neutralization causes the temperature to rise to about 70°C. To the warm solution was added 6.6 g (0.02 mol) of sodium tungstate dihydrate. A standard pH electrode was inserted into the solution and 1.2 moles of 30% hydrogen peroxide were added in portions. The strongly exothermic reaction was maintained at 63-65°C by means of an ice bath for about 15 minutes. During this time, the pH dropped from about 5.5 to about 4.11. In order to maintain a minimum pH of 4, a solution of 0.5 molar sodium hydroxide in 100 ml of water may be added dropwise during the remainder of the reaction, if desired. After reacting for an additional 1 hour at 65°C, the solution was cooled to 40°C and treated with the remaining sodium hydroxide solution to give 176 g (100%) of disodium cis-epoxysuccinate after concentration in vacuo at 40°C salt as a product.

(2) Preparation of N-substituted 2-amino-3-hydroxysuccinic acid derivatives

Procedure: 9.35 g (1 mole) of disodium cis-epoxysuccinate and 1 mole of the corresponding ammonia were added to 25 ml of water at room temperature and the reactor was closed. While stirring, the mixture was refluxed at 90-95°C for 12 hours, and the reaction mixture was dried in a rotary evaporator to obtain the product, the purified product was characterized by NMR spectroscopy.

Also, one skilled in the art knows how to characterize a compound.

The corresponding dicarboxylic or monocarboxylic acid compounds for the above disodium salts can be obtained by neutralization with commonly used acids well known in the art.

All the compounds of formula (I) in the present application can be synthesized using the above method or a method substantially the same or similar to the above method.

Embodiment 2 is used for testing the electrochemical method of corrosion rate

The electrochemical test method used for corrosion rate is as follows:

A. Sample

1. Metallurgy - C1010 mild steel seamless sample

2. Dimensions - 1/2" long, 1/2" outer diameter

3. Finishing - Matte #600

(The above 1-3 are the specifications of the sample)

4. Mounting - Tubular samples should be mounted in sample holders with two Teflon spacers and a Delrin end cap. Observe the sample before installation - is it a seamless sample (is there a weld mark on the inside surface)? Are there any large imperfections/dents/scratches on the metal surface? Do not use the sample if it is not seamless or if any defects are found.

5. Polishing - Lightly polish the mounted samples again with #600SiC paper before testing.

6. Cleaning - Then, clean the sample by rinsing with acetone and wipe clean with Kimwipes.

7. After cleaning, use white nylon gloves to handle samples to avoid contamination with fingerprints or oil from fingers;

8. Coating - Then, coat the edges of the mild steel samples with Microstop Lacquer varnish to minimize crevice corrosion. Use a heat gun to dry the paint. Then, attach the sample holder to the shaft of the rotator.

9. Sample holder - Wrap the stainless steel sample holder with Teflon tape to electrically isolate the stainless steel holder from the system, exposing only the mild steel sample.

10. No pre-passivation required.

B. Test solution:

1. Prepare a solution with specific water chemistry and heat to 50°C.

2. Volume - 800ml of test solution is introduced into the glass test cell.

3. Temperature/Gas - Turn on the temperature control to 120F and (at a very low rate) purge the solution with air.

4. pH - Before each test, calibrate the pH meter/probe (two-point calibration). Insert the calibrated pH probe into the test solution. After the system temperature and pH reached steady state values, the solution pH was adjusted to the set point (with diluted KOH or _H2SO4 or _{CO2 )} .

5. Inhibitor administered with 25PPM active chemical (make 4 gm/L active stock of inhibitor solution and adjust its pH to set point; add 5 mL of stock to test cell).

C. Electrochemical Measurements

1. Rotate the cylindrical electrode - set the rotator speed to 500 rpm.

2. Polarization resistance (Rp) - Rp measurements should be made at a potential sweep rate of 0.1 mV/sec within a corrosion potential (Ecorr) of 20 mV from the cathodic region to the anodic region.

3. Tafel diagrams - At the end of each experiment, potentiodynamic polarization measurements were performed to obtain Tafel diagrams for the cathode and anode at a potential scan rate of 0.5 mV/sec. Cathode Tafel scan is first performed from (Ecorr-350mV) to Ecorr. Then, the anode scan is performed from Ecorr to (Ecorr+350mV).

4. Calculation of corrosion rate

(1) Tafel extrapolation—Tafel plots were extrapolated to corrosion potentials to determine corrosion rate in mpy (Gamry software, E/Log I plot), cathodic Tafel slope (Bc) and anodic Tafel slope (Ba).

(2) Polarization resistance - Based on the Stern-Geary equation (Gamry software), the corrosion rate was determined using the values of Ba, Bc (obtained in (1)) and Rp. Corrosion rate (mpy) versus time curves can be plotted using Gamry software. Use this plot to determine the steady state corrosion rate.

(3) Determine the average corrosion rate calculated from Tafel extrapolation and Rp measurement.

In addition, the water chemistry of the test water used in the following examples is shown in Table 1 below:

Table 1

Ca hardness (ppm by weight as CaCO3 ₎ 180 Mg hardness (ppm by weight as CaCO3 ₎ 66 Alkaline (ppm by weight as CaCO3 ₎ 170 Cl- (ppm by weight as ion) 256 _SO4 (ppm by weight as ion) 63

The test of embodiment 3 corrosion rate

Another test method for corrosion rate (or corrosion inhibition effect) is as follows:

1. Put 2L of deionized water into a 2L beaker, and add a corresponding volume of inorganic salt solution (calcium chloride, magnesium chloride, sodium chloride, sodium sulfate, etc.) in addition to alkalinity to configure the corresponding water quality. Turn on the heating and raise the temperature to 45°C;

2. After adding the corresponding products (generally, the medicament containing dispersant is added first, and then zinc salt, phosphate and other products that need to be dispersed), adjust the pH value to about 6.5 with dilute sodium hydroxide solution/dilute sulfuric acid solution (mainly The purpose is to eliminate the acidity/alkalinity brought by the product), and then add corresponding NaHCO ₃ to adjust the alkalinity;

3. If the experimental water quality needs to control the pH value, adjust the pH value of the solution through dilute sulfuric acid/dilute sodium hydroxide solution, and after equilibrating at 45°C for 1 to 2 hours, confirm/adjust the pH value and put it into the coupon; if the water quality is not good pH value control is required. After equilibrating for 1 to 2 hours, put the coupon directly; before putting the coupon, record the coupon number and the corresponding weight;

4. Due to the evaporation of water, each beaker needs to be replenished with water to the corresponding volume, twice a day;

(The above steps 1-4 are all carried out under the condition that the temperature is 45°C and the rotating speed is 100-150 rpm).

5. The experiment period is three days, stop the experiment after three days, remove the coupon, dry the surface moisture with paper, and then dry it in an oven; please take pictures of the front and back before cleaning; first remove the floating rust on the surface by physical methods before cleaning the coupon. Wash with 0.8% (w/v) hexamethyltetramine hydrochloric acid solution (1 part of concentrated hydrochloric acid diluted in 4 parts of water), rinse with deionized water, wipe dry, rinse with acetone, dry and weigh; in principle, The pickling time for each coupon shall not exceed one minute.

And, the water chemistry of the water that is used for testing in the following examples is as shown in Table 2 below:

Table 2

Ca hardness (ppm by weight as CaCO3 ₎ 100 Mg hardness (ppm by weight as CaCO3 ₎ 50 Alkaline (ppm by weight as CaCO3 ₎ 100 Cl- (ppm by weight as ion) 200 _SO4 (ppm by weight as ion) 100

Embodiment 4 corrosion inhibitor

A kind of corrosion inhibitor comprising polymaleic acid, ₂ -n-butylamino-3-hydroxyl-succinic acid disodium salt and ZnCl2, wherein polymaleic acid and 2-n-butylamino-3-hydroxyl-succinate The weight ratio between the acid disodium salt is 5:5 and the weight ratio between ₂ -n-butylamino-3-hydroxy-succinic acid disodium salt and ZnCl is 5:2.

Wherein, the corrosion inhibitor is obtained by simply mixing the above three components together.

Embodiment 5 tests the corrosion rate of corrosion inhibitor M and comparison composition E-F

In this embodiment, all components of Composition M and Comparative Compositions E-F were added directly to the aqueous solutions tested in any order and at the concentrations indicated in the table below. Also, Composition M and Comparative Compositions E-F were tested according to the method described in Example 2.

The compositions and test results of Composition M and Comparative Compositions E-F are shown in Table 3.

table 3

[2-n-Butylamino-3-hydroxy-succinic acid disodium salt: X=NH, R=n-butyl, disodium salt]

Wherein, 2-n-butylamino-3-hydroxy-succinic acid disodium salt was prepared according to Example 1, and polymaleic acid was purchased from Wujin Fine Chemical Factory.

As can be seen from Table 3, the effect of formula (I) compound and water-soluble polymer combination is significantly better than using formula (I) compound or using water-soluble polymer alone, illustrating that formula (I) compound and water-soluble polymer There are synergistic technical effects among them.

Embodiment 6 tests the corrosion rate of corrosion inhibitor A-D and comparison composition G-J

In this embodiment, all components of Compositions A-D and Comparative Compositions G-J were added directly to the aqueous solution being tested in any order and at the concentrations indicated in the table below. Also, Compositions A-D and Comparative Compositions G-J were tested according to the method described in Example 3.

The compositions and test results of Compositions A-D and Comparative Compositions G-J are shown in Table 4.

Table 4

[2-n-Butylamino-3-hydroxy-succinic acid disodium salt: X=NH, R=n-butyl, disodium salt]

Wherein, 2-n-butylamino-3-hydroxy-succinic acid disodium salt was prepared according to Example 1, and polymaleic acid was purchased from Wujin Fine Chemical Factory.

Moreover, polymaleic acid is similar to antiscaling agent, and zinc salt is corrosion inhibitor.

As can be seen in Table 4, the corrosion inhibition effect of the combination of zinc salt and formula (I) compound or water-soluble polymer is inferior to the combination of zinc salt and formula (I) compound and water-soluble polymer. Simultaneously, as can be seen from the comparative composition I and comparative composition J of Table 4, the significant enhancement of the corrosion inhibition effect is not due to the combination of the additive zinc salt and the compound of formula (I) or the water-soluble polymer, but due to the compound of formula (I) Synergy with water-soluble polymers.

From the compositions A, B and C of table 4, it can be seen that the corrosion inhibitory effect is enhanced with the increase of the amount of the compound of formula (I); meanwhile, as in the composition C and D test results in table 4, the As shown by the comparison, the addition of zinc salt can significantly enhance the synergistic effect between the compound of formula (I) and the water-soluble polymer.

Embodiment 7 tests the corrosion rate of corrosion inhibitor N and comparison composition K-L

In this embodiment, all components of Composition N and Comparative Compositions K-L were added directly to the aqueous solutions tested in any order and at the concentrations indicated in the table below. Also, Composition N and Comparative Compositions K-L were tested according to the method described in Example 3.

The compositions and test results of Composition N and Comparative Compositions K-L are shown in Table 5.

table 5

[2-n-Butylamino-3-hydroxy-succinic acid disodium salt: X=NH, R=n-butyl, disodium salt]

Wherein, 2-n-butylamino-3-hydroxy-succinic acid disodium salt was prepared according to Example 1, and polyacrylic acid was purchased from Nalco.

As can be seen from the comparative composition K and comparative composition L in Table 5, the significant enhancement of the corrosion inhibition effect is not due to the combination of the additive zinc salt and the compound of formula (I) or the water-soluble polymer, but due to the compound of the formula (I) and the water-soluble Synergy between polymers.

The present disclosure is an exemplar of principles of embodiments of the invention and is not intended to limit the application in any form or material or to limit the application to the particular embodiments set forth. For those skilled in the art, it is obvious that the elements, compounds, polymers, compositions, compositions, formulations, methods of implementation of the technical solutions of the present application can be changed, changed, modified and evolved without departing from the above Within the spirit and scope of the disclosed embodiments and technical solutions of the present application, such as defined in the claims. Embodiments of these changes, changes, modifications and evolutions are included in the equivalent embodiments of the present application, which are included in the scope of the claims of the present application. Although embodiments of the present application may be embodied in many different forms, this document describes in detail some embodiments of the invention. Furthermore, embodiments of the present application include any and all possible combinations of any, some, and all elements of the various embodiments described herein. Any and all patents, patent applications, and other documents mentioned in this application or in any cited patent, any cited patent application, or other cited data are hereby incorporated by reference in their entirety.

The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to those of ordinary skill in the art. All such alternatives and variations are intended to be included within the scope of the claims, where the term "comprising" means "including, but not limited to".

This completes the description of the preferred and alternative embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiments described herein and those equivalents are intended to be encompassed by the claims appended hereto.

Claims (11)

1. a composite corrosion inhibitor, described compositions comprise have following formula (I) compound or Its salt and water-soluble polymer:

Wherein, X represents NH, NR¹Or O；

R and R¹Identical or different and be each independently selected from C_1-10Alkyl.

2. compositions as claimed in claim 1, wherein, in formula (I), X is NH and R For C_1-10Alkyl；And optionally, X is NH and R is normal-butyl.

3. compositions as claimed in claim 1, wherein, in formula (I), X is NR¹, and R and R¹It is C_1-10Alkyl；And optionally, R and R¹It is methyl.

4. compositions as claimed in claim 1, wherein, described in there is the compound of formula (I) Salt is the one or more of salt selected from the group consisted of: the mono-salt of sodium, potassium, ammonium, calcium or magnesium Or disalt.

5. compositions as claimed in claim 1, wherein, described water-soluble polymer is that choosing is free The one or more of polymer of group consisting of: poly, polyacrylic acid, acrylic acid and horse Come the copolymer of anhydride and acrylic acid and the copolymer of 2-acrylamide-2-methyl propane sulfonic.

6. compositions as claimed in claim 1, wherein, it is NH that described compositions comprises wherein X And the compound or its salt with formula (I) that R is normal-butyl and poly.

7. compositions as claimed in claim 1, also includes the one selected from the group consisted of Or more kinds of additive: zinc salt, molybdate, tungstates, pink salt and silicate.

8. the compositions as according to any one of claim 1-7, wherein, described compositions does not includes Phosphorus-containing compound.

9. the compositions as according to any one of claim 1-7, wherein, described compound is with described Weight ratio between water-soluble polymer is 1:50 to 50:1, and optionally, wherein said compound with Weight ratio between described water-soluble polymer is 1:5 to 5:1.

10. compositions as claimed in claim 7, wherein, between described compound and described zinc salt Weight ratio be 1-50:0.1-5, the weight ratio between described compound and described molybdate is 1-50:5-50, the weight ratio between described tungstates and described compound is less than or equal to 500:1, described Weight ratio between pink salt and described compound is less than or equal to 10:1, and/or described compound and described Weight ratio between silicate is 1-50:5-100.

11. compositionss as according to any one of claim 1-10 are used for suppressing ferrum gold as corrosion inhibiter The purposes of the corrosion of genus or galvanized steel.