Fatty acid morpholine for rust prevention of black metal, compound agent and preparation method of fatty acid morpholine

Abstract

The invention discloses fatty acid morpholine for rust prevention of black metal, a compounding agent and a preparation method of the fatty acid morpholine, and the specific preparation process of the fatty acid morpholine comprises the following steps: mixing fatty acid and morpholine in a molar ratio of 1: (1-3) under the conditions that the temperature is 20-30 DEG C and the relative environmental humidity is 40-70%, carrying out condensation acylation reaction in a stirring state, curing, and carrying out vacuum drying to obtain the fatty acid morpholine. The fatty acid is monocarboxylic acid or polybasic carboxylic acid with the carbon chain length of 4-18. The adopted raw materials are easy to obtain and low in toxicity, the reaction condition is mild, the process is simple, the prepared compound structure contains hydrophilic functional groups such as amide and ether and also contains hydrophobic chain segments, the hydrophilic groups can be adsorbed on the metal surface to form a stable protective film, and the metal surface is protected. And the hydrophobic chain segment can effectively prevent water from being enriched on the metal surface, the two groups act together, a good anti-rust effect on black metal is achieved, the production process is environmentally friendly, and energy consumption is low.

Description

Technical Field

[0001] The invention belongs to the technical field of metal antirust, and particularly relates to fatty acid morpholine for black metal antirust, a compounding agent and a preparation method thereof. Background Art

[0002] In modern industrial society, metal materials play an important role in the fields of construction, transportation, machinery and chemical industry due to their excellent mechanical properties. However, metal corrosion not only causes huge economic losses, but also may lead to major safety accidents and environmental problems. In addition, problems such as pipeline leakage caused by metal corrosion will cause environmental damage. Therefore, good metal corrosion prevention is of great significance to social and economic development.

[0003] Most of the metal materials currently used are ferrous metals. There are many ways to prevent rust on ferrous metals, such as coating, electroplating, surface treatment and vapor phase rust prevention. Among them, vapor phase rust prevention technology has its unique advantages: ① It can achieve comprehensive rust prevention of parts; ② It is an active rust prevention technology that can continuously provide long-term protection and will not lose its rust prevention function due to film damage; ③ Metal parts protected by vapor phase rust prevention technology do not need to be cleaned before use.

[0004] Among the gas phase rust prevention products, rust prevention powders have gained more and more attention due to their simple preparation process and rich application scenarios. However, the corrosion inhibitor raw materials used in the current rust prevention powders have the problem of high toxicity, and the existing product design is mainly based on the experience accumulation of technicians, lacking theoretical support and guidance. In order to reduce the toxicity of gas phase corrosion inhibitors and make them more in line with environmental protection requirements, technicians have done a lot of research work.

[0005] The Chinese patent application with application number CN201811557224.7 discloses an environmentally friendly multi-metal water-based rust inhibitor, the raw materials of which contain water-soluble resin, silane coupling agent, passivator, silica sol, pH adjuster, surfactant, plant corrosion inhibitor, compound metal corrosion inhibitor and deionized water. The environmentally friendly multi-metal water-based rust inhibitor of the invention uses water-soluble resin as a support, organic silane and silica sol as film-forming agents, supplemented by special compound metal corrosion inhibitors and corrosion inhibitors extracted from plants. It is green, environmentally friendly, economical and practical. The invention uses substances extracted from plants as corrosion inhibitors, which is a more comprehensive way of environmental protection requirements, but the method is cumbersome and inefficient, making it difficult to achieve commercial application. The Chinese patent application number CN201510510199.7 discloses a metal rust inhibitor and a preparation method thereof, wherein the rust inhibitor includes sodium silicate, sodium polyacrylate, mercaptobenzothiazole, benzotriazole, sodium tripolyphosphate, hexamethylenetetramine, imidazoline, alkylamino alcohol, furfural, polyphosphate, ethanolamine, sodium borate and ethanol; the preparation method is to first heat the mixture of sodium silicate, sodium polyacrylate, mercaptobenzothiazole, benzotriazole, sodium tripolyphosphate, hexamethylenetetramine, imidazoline, alkylamino alcohol, furfural, ethanolamine and ethanol to 50-60°C, then add polyphosphate and sodium borate, continue to heat to 85-90°C, keep warm for 2-3 hours, and then cool. The rust inhibitor of the invention has good compatibility with various materials, long anti-rust time, up to 4-6 months, and good adaptability to copper and aluminum materials. At present, in the research on the anti-rust mechanism of corrosion inhibitors, only the anti-rust mechanism of benzotriazole on copper is relatively clear, while the anti-rust mechanism of corrosion inhibitors on ferrous metals is still lacking in-depth research. Therefore, it is urgent to develop a new corrosion inhibitor with good anti-rust effect on ferrous metals. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a fatty acid morpholine, a compounding agent and a preparation method thereof for rust prevention of black metals. The fatty acid morpholine and the compounding agent of the present invention have excellent rust prevention performance for black metals, and the preparation method provided by the present invention is simple to operate, the raw material toxicity is low, the production process is green and environmentally friendly, and the energy consumption is low.

[0007] The technical solution of the present invention is as follows:

[0008] One of the purposes of the present invention is to provide a method for preparing fatty acid morpholine for rust prevention of black metals. The specific preparation process is: under the conditions of 20-30°C and relative humidity of 40-70%, a fatty acid and morpholine in a molar ratio of 1:(1-3) are mixed, a condensation acylation reaction occurs under stirring, and the fatty acid morpholine is obtained after aging.

[0009] Furthermore, the fatty acid is a monocarboxylic acid or a polycarboxylic acid with a carbon chain length of 4 to 18.

[0010] Furthermore, the rotation speed of the stirring process is 60 to 90 r / min, and the time is 10 to 30 min.

[0011] Furthermore, the temperature of the aging process is 30-40° C. and the time is 18-24 hours.

[0012] The second object of the present invention is to provide a fatty acid morpholine for rust prevention of black metals, which is prepared by any of the above-mentioned preparation methods.

[0013] Furthermore, the fatty acid morpholine has a highest occupied orbital HOMO energy in the range of -3.0 eV to -5.0 eV, and a lowest unoccupied orbital LUMO energy in the range of -1.3 eV to -2.0 eV.

[0014] The third object of the present invention is to provide a fatty acid morpholine compound for rust prevention of black metals, wherein the compound comprises any of the above-mentioned fatty acid morpholine as a main corrosion inhibitor.

[0015] Furthermore, the compounding agent is composed of the following components in weight percentage: 20-60wt% of fatty acid morpholine, 30-60wt% of organic acid salt, and 5-20wt% of auxiliary agent, and the total weight of the above components is 100wt%.

[0016] Furthermore, the organic acid salt is one or a mixture of aromatic acid salts and fatty acid salts.

[0017] Furthermore, the particle size of the fatty acid morpholine compound is 0.1 to 1 mm.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention provides a method for preparing fatty acid morpholine for rust prevention of black metals, which has mild reaction conditions, simple process, green and environmentally friendly production process and low energy consumption.

[0020] 2. The present invention provides a method for preparing fatty acid morpholine for rust prevention of black metals. The raw materials used are easily available and less toxic, and the reaction conditions are mild and the process is simple. The prepared compound structure contains both hydrophilic amide, ether and other functional groups and hydrophobic segments. The hydrophilic groups can be adsorbed on the metal surface to form a stable protective film, while the hydrophobic segments can effectively prevent the enrichment of water on the metal surface. The two groups work together to have a good rust prevention effect on black metals.

[0021] 3. A fatty acid morpholine for rust prevention of black metals provided by the present invention has the highest occupied orbital HOMO energy in the range of -3.0eV to -5.0eV, and has the lowest unoccupied orbital LUMO energy in the range of -1.3eV to -2.0eV. The group with high HOMO energy is more likely to give electrons to form coordination bonds with the 3d orbit of the metal, resulting in stable chemical adsorption. The lower the LUMO orbital energy, the easier it is to form feedback bonds with the metal surface, thereby enhancing the adsorption effect. The fatty acid morpholine selected by the present invention can form a stable protective film on the metal surface within the above-mentioned orbital energy range, thereby slowing down the generation of rust.

[0022] 4. A fatty acid morpholine compounding agent for rust prevention of black metals provided by the present invention, since fatty acid morpholine itself has a good rust prevention effect on black metals, but due to its relatively large molecular size, there is a steric hindrance effect during the adsorption process, so that the density of the adsorption layer on the metal surface is lacking, and the compounding of small molecule organic acids can fill the area not covered by fatty acid morpholine, so that the rust prevention effect is greatly improved. Therefore, after the fatty acid morpholine is compounded with the synergist, the rust prevention effect on black metals is more prominent, and it has a high practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the model of the highest occupied orbital (HOMO) of the fatty acid morpholine prepared in Example 1 of the present invention;

[0024] Figure 2 Schematic diagram of the model of the lowest unoccupied orbital LOMO of fatty acid morpholine prepared in Example 1 of the present invention;

[0025] Figure 3 This is a schematic diagram of the test results of the antirust performance of fatty acid morpholine on steel prepared in Example 1 of the present invention;

[0026] Figure 4 This is a schematic diagram of the test results of the rust-proof performance of the fatty acid morpholine compound prepared in Example 8 on steel;

[0027] Figure 5 This is a schematic diagram of the direct contact corrosion test results of the fatty acid morpholine compound prepared in Example 8 on steel;

[0028] Figure 6 This is a schematic diagram of the test results of the rust prevention performance of the fatty acid morpholine compound prepared in Example 8 on steel after accelerated consumption in the present invention. DETAILED DESCRIPTION

[0029] The following is combined with the preferred embodiment and with reference to the attached Figure 1-6, the present invention is further described. The endpoints and any values ​​of the ranges disclosed in the present invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values; for numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein; the materials, reagents, etc. used in the following examples, unless otherwise specified, can be obtained from commercial channels; the experimental methods in the following examples, unless otherwise specified, are all conventional methods.

[0030] Example 1

[0031] The present embodiment provides a method for preparing fatty acid morpholine for rust prevention of black metals. The specific preparation process is: under the conditions of 25° C. and a relative ambient humidity of 55%, a fatty acid and morpholine are mixed in a molar ratio of 1:3, stirred at a speed of 80 r / min for 10 min, so that the fatty acid and morpholine undergo condensation acylation reaction, and matured at 40° C. for 18 h to obtain the fatty acid morpholine.

[0032] In this embodiment, the fatty acid is palmitic acid.

[0033] Example 2

[0034] The present embodiment provides a method for preparing fatty acid morpholine for rust prevention of black metals. The specific preparation process is: under the conditions of 20° C. and a relative ambient humidity of 40%, a fatty acid and morpholine are mixed in a molar ratio of 1:1, stirred at a speed of 60 r / min for 30 minutes, so that the fatty acid and morpholine undergo condensation acylation reaction, and matured at 30° C. for 24 hours to obtain the fatty acid morpholine.

[0035] In this embodiment, the fatty acid is succinic acid.

[0036] Example 3

[0037] The present embodiment provides a method for preparing fatty acid morpholine for rust prevention of black metals. The specific preparation process is: under the conditions of 30° C. and a relative ambient humidity of 70%, a fatty acid and morpholine are mixed in a molar ratio of 1:3, stirred at a speed of 90 r / min for 20 min, so that the fatty acid and morpholine undergo condensation acylation reaction, and matured at 35° C. for 20 h to obtain the fatty acid morpholine.

[0038] In this embodiment, the fatty acid is oleic acid.

[0039] Example 4

[0040] This embodiment provides a fatty acid morpholine compound for rust prevention of black metals, wherein the compound comprises the fatty acid morpholine prepared in Example 1 as a main corrosion inhibitor.

[0041] The compounding agent is composed of the following components in weight percentage: 60 wt % of fatty acid morpholine, 30 wt % of organic acid salt, and 10 wt % of auxiliary agent.

[0042] In this embodiment, the fatty acid morpholine is palmitic acid morpholine, the organic acid salt is sodium benzoate, and the particle size of the fatty acid morpholine compound is 0.5 mm.

[0043] Example 5

[0044] This embodiment provides a fatty acid morpholine compound for rust prevention of black metals, wherein the compound comprises the fatty acid morpholine prepared in Example 1 as a main corrosion inhibitor.

[0045] The compounding agent is composed of the following components in weight percentage: 45 wt% of fatty acid morpholine, 50 wt% of organic acid salt, and 5 wt% of auxiliary agent.

[0046] In this embodiment, the fatty acid morpholine is stearic acid morpholine, the organic acid salt is sodium benzoate, and the particle size of the fatty acid morpholine compound is 0.1 mm.

[0047] Example 6

[0048] This embodiment provides a fatty acid morpholine compound for rust prevention of black metals, wherein the compound comprises the fatty acid morpholine prepared in Example 1 as a main corrosion inhibitor.

[0049] The compounding agent is composed of the following components in weight percentage: 20 wt % of fatty acid morpholine, 60 wt % of organic acid salt, and 20 wt % of auxiliary agent.

[0050] In this embodiment, the fatty acid morpholine is sebacate morpholine, the organic acid salt is sodium benzoate, and the particle size of the fatty acid morpholine compound is 1 mm.

[0051] Example 7

[0052] This embodiment provides a fatty acid morpholine compound for rust prevention of black metals, wherein the compound comprises the fatty acid morpholine prepared in Example 1 as a main corrosion inhibitor.

[0053] The compounding agent is composed of the following components in percentage by weight: 60 wt% of fatty acid morpholine, 30 wt% of organic acid salt and 10% of auxiliary agent.

[0054] In this embodiment, the fatty acid morpholine is palmitic acid morpholine, the organic acid salt is ammonium benzoate, and the particle size of the fatty acid morpholine compound is 0.5 mm.

[0055] Example 8

[0056] This embodiment provides a fatty acid morpholine compound for rust prevention of black metals, wherein the compound comprises the fatty acid morpholine prepared in Example 1 as a main corrosion inhibitor.

[0057] The compounding agent is composed of the following components in weight percentage: 50 wt % of fatty acid morpholine, 40 wt % of organic acid salt, and 10 wt % of auxiliary agent.

[0058] In this embodiment, the fatty acid morpholine is palmitic acid morpholine, the organic acid salt is 20% ammonium benzoate and 20% sodium octanoate, and the particle size of the fatty acid morpholine compound is 0.5 mm.

[0059] Example 9

[0060] This embodiment provides a fatty acid morpholine compound for rust prevention of black metals, wherein the compound comprises the fatty acid morpholine prepared in Example 1 as a main corrosion inhibitor.

[0061] The compounding agent is composed of the following components in weight percentage: 35 wt % of fatty acid morpholine, 55 wt % of organic acid salt, and 10 wt % of auxiliary agent.

[0062] In this embodiment, the fatty acid morpholine is palmitic acid morpholine, the organic acid salt is 18% ammonium benzoate and 37% sodium octanoate, and the particle size of the fatty acid morpholine compound is 0.5 mm.

[0063] Comparative Example 1

[0064] The difference from Example 1 is that this comparative example contains 100% palmitic acid.

[0065] Comparative Example 2

[0066] The difference from Example 1 is that this comparative example is not subjected to aging treatment.

[0067] Comparative Example 3

[0068] The difference from Example 1 is that the preparation process of this comparative example is carried out at 40° C. and a relative humidity of 80%.

[0069] Comparative Example 4

[0070] The difference from Example 1 is that the molar ratio of fatty acid to morpholine in this comparative example is 4:3.

[0071] Implementation effect evaluation

[0072] The excellent effects achieved by the present invention are further illustrated by conducting specific tests on the fatty acid morpholine and fatty acid morpholine compound prepared in Examples 1-9 and Comparative Examples 1-5:

[0073] Grind No. 10 steel columns or steel sheets that meet the relevant provisions of GB / T 699 with No. 400 aluminum oxide sandpaper to remove pits, scratches and rust, so that the surface roughness is 0.4-0.6μm. Clean the test piece with three times of anhydrous ethanol, blow dry with hot air, cool to room temperature, and place in a desiccator for use.

[0074] Anti-rust ability test: According to the relevant provisions of GB / T 35491-2017, 10 mL of a 35% mass fraction of propylene glycol aqueous solution was injected into the bottom of the wide-mouth bottle to form a humidity of 90% at 20°C. (0.1±0.005) g of fatty acid morpholine and fatty acid morpholine compound prepared in Examples 1-9 and Comparative Examples 1-5 were weighed and evenly spread in a weighing bottle with an inner diameter of (40±2) mm and a height of 10-20 mm. The weighing bottle was placed in the center of the bottom of the wide-mouth bottle, and the assembled wide-mouth bottle was placed in an incubator at (20±1)°C, left for 20 hours and taken out, and the aluminum tube on the wide-mouth bottle was quickly filled with water at 0-2°C, and then immediately placed in the incubator, and the experimental device was taken out after 3 hours; the water in the aluminum tube was poured out, the test piece was immediately taken out, and the rust on the surface of the test piece was checked.

[0075] Direct contact corrosion test: According to the relevant provisions of GB / T 35491-2017, weigh (0.25±0.005)g of fatty acid morpholine and fatty acid morpholine compound respectively, and evenly spread them on the 75mm×50mm line range on the 100mm×50mm steel sheet, and test the contact corrosion of the compound to steel in an environment of (50±2)℃ and relative humidity of 62%~68%. Take it out after 20 hours, remove the compound from the steel sheet immediately, clean and dry it with ethanol, and check the rust marks on the surface of the steel sheet. Record the rust on the surface covered by the compound and the surface not covered.

[0076] Anti-rust ability test after accelerated consumption: Take 1.00g of fatty acid morpholine compound powder and put it into a φ120mm watch glass, place it in a (38±2)℃ electric heating blast drying oven for 120h, then take it out, cover the watch glass and cool it naturally to room temperature. Then, determine the anti-rust ability of the compound after consumption on steel according to the above anti-rust ability test.

[0077] The present invention also tests the rust prevention ability of the fatty acid morpholine compound prepared in Example 8 on metal manganese and chromium.

[0078] The test results are shown in the table below:

[0079] Table 1 Test results statistics

[0080]

[0081]

[0082] Figure 3-6 The figure is a test result diagram of the rust prevention ability of fatty acid morpholine prepared in Example 1 of the present invention on steel, and a schematic diagram of the test results of the rust prevention ability, direct contact corrosion, and rust prevention ability of fatty acid morpholine compound prepared in Example 8 on steel. Figure 3 It can be seen from the above that the fatty acid morpholine prepared by the present invention has good rust-proof ability for steel; Figure 4-6 It can be seen that the fatty acid morpholine compound prepared by the present invention has good rust prevention ability for steel and can improve the corrosion resistance of steel.

[0083] The invention takes quantum chemistry as the theoretical basis, and uses the molecular structure with suitable HOMO and LOMO orbits as the corrosion inhibitor molecule for black metal rust prevention by designing and optimizing. With fatty acid and morpholine as raw materials, fatty acid morpholine is prepared in one step by solid phase chemical synthesis. With homemade fatty acid morpholine as the main corrosion inhibitor, aromatic acid salt and fatty acid salt as synergists, a compound agent for black metal rust prevention is prepared. The invention is simple to operate, easy to scale up the process, and broadens the selection range of the corrosion inhibitor, and has significant practical application value.

[0084] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for preparing fatty acid morpholine for rust prevention of black metals, characterized in that: The specific preparation process is: under the conditions of 20-30°C and relative humidity of 40-70%, a fatty acid and morpholine in a molar ratio of 1:(1-3) are mixed, a condensation acylation reaction occurs under stirring, and after aging, the fatty acid morpholine is obtained.

2. The method for preparing fatty acid morpholine for rust prevention of black metals according to claim 1, characterized in that: The fatty acid is a monocarboxylic acid or a polycarboxylic acid with a carbon chain length of 4 to 18.

3. A method for preparing fatty acid morpholine for rust prevention of black metals according to claim 1, characterized in that: The rotation speed of the stirring process is 60 to 90 r / min, and the stirring time is 10 to 30 min.

4. The method for preparing fatty acid morpholine for rust prevention of black metals according to claim 1, characterized in that: The temperature of the aging process is 30-40° C. and the time is 18-24 hours.

5. A fatty acid morpholine for rust prevention of black metals, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 4.

6. The fatty acid morpholine for rust prevention of black metals according to claim 5, characterized in that: The fatty acid morpholine has a highest occupied orbital HOMO energy in the range of -3.0 eV to -5.0 eV, and a lowest unoccupied orbital LUMO energy in the range of -0.13 eV to -2.0 eV.

7. A fatty acid morpholine compound for rust prevention of black metals, characterized in that: The compound agent uses the fatty acid morpholine described in claim 5 or 6 as a main corrosion inhibitor.

8. A fatty acid morpholine compound for rust prevention of black metals according to claim 7, characterized in that: The invention is composed of the following components in weight percentage: 20-60 wt% of fatty acid morpholine, 30-60 wt% of organic acid salt and 5-20 wt% of auxiliary agent, and the total amount of the above components is 100 wt%.

9. A fatty acid morpholine compound for rust prevention of black metals according to claim 8, characterized in that: The organic acid salt is one or a mixture of aromatic acid salt and fatty acid salt.

10. The fatty acid morpholine compound for rust prevention of black metals according to claim 8, characterized in that: The particle size of the fatty acid morpholine compound is 0.1-1 mm.

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