A bio-based gas phase rust preventive and a method for preparing the same

Abstract

The application discloses a kind of bio-based gas phase rust preventive, including the following components: triethanolamine, borax, ammonium benzoate, sodium gluconate, sodium citrate, tryptophan, sodium aminotri (methylphosphine), organic polymer containing glycoside unit and sodium sulfonate unit and water.The gas phase corrosion inhibitor and gas phase rust preventive material provided by the application belong to multi-metal universal type rust preventive material, suitable for galvanized aluminum magnesium steel material, galvanized steel material and cold steel material, etc., with excellent rust prevention effect, especially under high temperature.The gas phase corrosion inhibitor and rust preventive material provided by the application belong to green and environmentally friendly type rust preventive material, and the raw materials used are low toxicity, environmentally friendly, and there is no dangerous chemical component in the raw materials.

Description

Technical Field

[0001] This invention relates to the field of vapor phase rust inhibitors, specifically to a bio-based vapor phase rust inhibitor and its preparation method. Background Technology

[0002] With the development of metal coating technology in my country, many new types of coated steel sheets have emerged, such as galvanized steel sheets and galvanized aluminum-magnesium steel sheets. Galvanized aluminum-magnesium steel sheets are a new type of highly corrosion-resistant coated steel sheet, belonging to high-end steel sheets, and are used in construction, automobiles, and other fields, with relatively high packaging requirements. Currently, there are no vapor phase corrosion inhibitors specifically for galvanized aluminum-magnesium steel sheets on the market. Therefore, it is extremely important to develop multi-metal universal vapor phase corrosion inhibitors and vapor phase corrosion inhibitors for galvanized aluminum-magnesium steel sheets and other coated steel sheets.

[0003] Vapor phase corrosion inhibitor (VCI) packaging technology combines rust-preventive paper with vapor phase corrosion inhibitors, utilizing volatile corrosion inhibitors (VCIs) to achieve rust prevention. It is characterized by its wide applicability and ease of use. In a confined space, the VCI-coated rust-preventive paper releases the inhibitor components, forming a protective film on the metal surface or adsorbing onto the metal surface to reduce corrosion. However, traditional VCIs often contain hazardous chemicals such as urotropine and benzotriazole, causing serious environmental pollution. Therefore, developing green, environmentally friendly, and universal VCIs and rust-preventive materials is crucial.

[0004] Currently, many vapor phase corrosion inhibitors contain molybdate (commonly sodium molybdate) to form a film and mitigate corrosion, providing good rust prevention. Examples include CN108373287A and CN106630722A. However, molybdenum is a heavy metal and still possesses a certain degree of toxicity, which does not align with the current development trend of green and environmentally friendly vapor phase corrosion inhibitors. Furthermore, sodium molybdate is expensive, increasing the manufacturing cost of multi-phase corrosion inhibitors.

[0005] Bio-based materials are a strategic emerging industry in my country. Sodium gluconate and sodium citrate, with their multi-hydroxyl structures, can form corresponding complexes with metal ions. They are inexpensive, bio-friendly, and non-toxic, and offer rust protection to the metals they protect, already being used in the field of rust inhibitors. However, the rust-preventive effect of sodium gluconate and sodium citrate needs further improvement. In galvanized steel sheets and galvanized aluminum-magnesium steel sheets, especially galvanized aluminum-magnesium steel sheets, which contain aluminum and magnesium—metals with higher reactivity than zinc—they are more susceptible to corrosion. Currently, many rust inhibitors combine inorganic and organic rust inhibitors, but the results are still not entirely satisfactory.

[0006] Inventors CN1038803116A and CN105399783A prepared organic glycosides as rust inhibitors, which showed better performance than alkanolamine-based vapor phase rust inhibitors. However, the inventors found that organic glycosides have weak adsorption capacity for metals at high temperatures, resulting in limited rust prevention effects above 60°C. Therefore, developing a bio-based vapor phase rust inhibitor that does not use sodium molybdate or other heavy metal ions, is bio-friendly, has excellent rust prevention performance, and particularly satisfactory rust prevention performance at high temperatures, has significant practical and commercial value. Summary of the Invention

[0007] To address the shortcomings of existing technologies in providing poor overall rust prevention for steel materials, such as galvanized steel sheets and galvanized aluminum-magnesium steel sheets, and their lack of environmental friendliness, this invention designs a bio-based, environmentally friendly, highly efficient, and universal vapor-phase rust inhibitor and its preparation method. This inhibitor can be used for effective protection of various coated metals, including cold-rolled, galvanized, and galvanized aluminum-magnesium steel sheets. This invention solves the above-mentioned technical problems through the following technical solutions:

[0008] A bio-based vapor phase rust inhibitor comprises the following components: triethanolamine, borax, ammonium benzoate, sodium gluconate, sodium citrate, tryptophan, sodium aminotrimethylphosphonate, an organic polymer containing glycoside units and sodium sulfonate units, and water.

[0009] Furthermore, the bio-based, environmentally friendly, highly efficient, and universal vapor phase rust inhibitor comprises the following components by weight percentage:

[0010] Triethanolamine 0.2–1 wt%, borax 2–5 wt%, ammonium benzoate 2–5 wt%, sodium gluconate 2–5 wt%, sodium citrate 1–2 wt%, tryptophan 0.05–0.2 wt%, sodium aminotrimethylphosphonate 0.5–1 wt%, organic polymers containing glycoside units and sulfonate units 1–3 wt%, with the balance being water.

[0011] Furthermore, the organic polymer containing glycoside units and sulfonate units is obtained by copolymerization of esterification products of alkyl glycosides and alkenyl succinic anhydrides with monomers containing sulfonic acid groups.

[0012] Specifically, the organic polymer containing glycoside units and sulfonate units is prepared by a method comprising the following steps:

[0013] (1) The alkyl glycoside is dissolved in an alcohol solvent, activated by adding an alkali, and then an alkenyl succinic anhydride is added under a protective atmosphere. The reaction is heated, distilled under reduced pressure, washed, and dried to obtain the esterification product of the alkyl glycoside and alkenyl succinic anhydride, which is used as the first monomer.

[0014] (2) The first monomer obtained in step (1) and the second monomer containing sulfonic acid groups are copolymerized. After copolymerization, the pH is adjusted to 8-9 with alkaline solution to obtain an organic polymer containing glycoside units and sulfonate units.

[0015] Further, in step (1), the alkyl glycoside is a C8-C16 alkyl glycoside with a degree of polymerization of 1.1-1.7, such as at least one of APG0810, APG1214, APG0812, APG0814, APG0816, and APG1216; the alcohol solvent is selected from at least one of ethanol and isopropanol, and the amount of alcohol solvent used is 5-20 times, for example, 10 times, the mass of the alkyl glycoside.

[0016] Further, in step (1), the addition of alkali for activation is NaOH and / or KOH, and the amount of alkali added is 1.1-1.3 times the molar number of the alkyl glycoside, and the activation is carried out at 30-40℃ for 1-2 hours; the alkenyl succinic anhydride is selected from at least one of propenyl succinic anhydride, 2-buten-1-yl succinic anhydride, and 2-hexen-1-succinic anhydride, and the molar ratio of alkyl glycoside to alkenyl succinic anhydride is 1:1-1.5.

[0017] Further, in step (1), the protective atmosphere is nitrogen and / or argon, and the heating reaction is carried out at 35-45°C for 2-5 hours. Post-treatment procedures such as vacuum distillation, washing, and drying are not particularly limited and can be performed using conventional methods in the art.

[0018] Further, in step (2), the second monomer containing the sulfonic acid group is selected from 2-acrylamido-2-methylpropanesulfonic acid, and the mass ratio of the first monomer to the second monomer is 10:18-25.

[0019] Further, in step (2), the copolymerization reaction conditions are as follows: the first monomer and the second monomer are added to an alcohol-water solution, an initiator is added, and the temperature is raised to initiate the copolymerization reaction; preferably, the alcohol-water solution is an ethanol-water solution with an ethanol volume concentration of 20-30%; the initiator is selected from at least one of sodium persulfate, potassium persulfate, and ammonium persulfate, and the amount of initiator is 0.3-0.5 wt% of the mass of the first monomer; the temperature is raised to 80-90℃ and the polymerization time is 3-5 h.

[0020] Further, in step (2), the alkaline solution is a 5-20 wt% aqueous solution of NaOH and / or KOH. After adjusting the pH, it is freeze-dried to obtain a powdered product, which is an organic polymer containing glycoside units and sulfonate units.

[0021] The organic polymer containing glycoside and sulfonate units prepared in this invention, when combined with other components, exhibits excellent rust-preventive properties. It possesses abundant rust-preventive functional groups (polyhydroxy glycosides) and anionic organic groups (carboxylates and sulfonates), demonstrating strong adsorption capacity for metals. Previously, bio-based components such as glycosides were used as rust inhibitors; these are small molecules, and while they offer good rust prevention, their performance deteriorates at temperatures above 60°C. This invention utilizes a high-molecular-weight organic polymer containing glycoside and sulfonate units, avoiding these drawbacks and maintaining excellent rust-preventive performance even at 60°C.

[0022] In the vapor phase corrosion inhibitor of this invention, sodium gluconate and sodium citrate are positively charged on the metal surface under acidic conditions, and the ionized (C6H) 11 O7) - and (C6H5O7) 3- Electrostatic attraction makes it easier for metals to adhere to galvanized steel sheets, and it readily reacts with reactive metals such as Fe, Zn, Mg, and Al. This is especially true for galvanized aluminum-magnesium steel sheets, as Al and Mg are highly reactive and more prone to rusting. When the anode metal participating in the electrochemical reaction loses electrons to form metal cations, these cations readily react with negatively charged (C6H4) atoms. 11 O7) - and (C6H5O7) 3- These compounds combine to form a corresponding complex film, providing rust protection for the protected metal. The lone pairs of electrons on the S and N atoms of the tryptophan molecule form surface complexes with the empty Fe orbitals, adsorbing onto the carbon steel surface and forming a dense adsorption film that effectively prevents metal corrosion. Sodium aminotrimethylphosphonate has excellent corrosion inhibition properties; when combined with sodium gluconate / sodium citrate in a certain proportion, it synergistically achieves excellent rust prevention.

[0023] The components of this invention, when combined, form a green, environmentally friendly, and universally effective corrosion inhibitor that provides synergistic and efficient rust prevention. It does not contain heavy metals such as sodium molybdate, is bio-friendly, and meets current requirements for green and environmentally friendly weather-phase corrosion inhibitors.

[0024] The present invention also provides a method for preparing a bio-based, environmentally friendly, efficient, and universal vapor phase corrosion inhibitor, wherein triethanolamine, borax, ammonium benzoate, sodium gluconate, sodium citrate, tryptophan, sodium aminotrimethylphosphonate, and an organic polymer containing glycoside units and sodium sulfonate units are added to water and stirred until dissolved to obtain an aqueous solution as the vapor phase corrosion inhibitor; furthermore, to ensure that the components of the corrosion inhibitor are fully dissolved, dissolution can be carried out at 15–40°C.

[0025] This invention also provides a vapor phase rust inhibitor material, comprising a rust-inhibiting base paper, the aforementioned vapor phase rust inhibitor, a polymer film, and a mesh or strip woven fabric. Specifically, a polymer film, such as polyethylene, polypropylene, or a mixture thereof, is laminated onto one side of the rust-inhibiting base paper. Then, a mesh or strip woven fabric is laminated onto the polymer film to enhance the carrier's flexibility and tear resistance. Finally, a layer of the aforementioned bio-based vapor phase rust inhibitor is dipped or sprayed onto the other side of the rust-inhibiting base paper (i.e., the back side of the composite polymer film), and dried to obtain the vapor phase rust inhibitor material. The lamination process involves heating the polymer material in an extruder, extruding it into a film, attaching it between the rust-inhibiting base paper and the woven fabric, and then pressing them together to form a composite product. Further, the drying temperature and time are not particularly limited; the moisture in the vapor phase rust inhibitor can be dried. When dipping or spraying a layer of the bio-based vapor phase rust inhibitor, the dipping or spraying amount of the bio-based vapor phase rust inhibitor is 10-20 g / m³. 2 For example, 12-15g / m 2 .

[0026] The vapor phase corrosion inhibitor and vapor phase rust inhibitor provided by this invention are multi-metal universal rust inhibitors, suitable for galvanized aluminum-magnesium steel, galvanized steel, and cold-rolled steel. The vapor phase corrosion inhibitor and rust inhibitor provided by this invention are green and environmentally friendly rust inhibitors; all raw materials used are low-toxicity and environmentally friendly, and contain no hazardous chemical components. Attached Figure Description

[0027] Figure 1 These are actual photos of the obtained rust-preventive material;

[0028] Figure 2 This is a schematic diagram of the obtained rust-preventive material;

[0029] Figure 3 This is a comparison chart showing the rust-preventive effects of the rust inhibitors in Comparative Example 1 and Example 1 on galvanized aluminum-magnesium steel sheets. Detailed Implementation

[0030] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0031] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0032] Preparation Example 1

[0033] (1) 1 mole of alkyl glycoside APG0810 was dissolved in 10 times the mass of isopropanol, 1.2 moles of NaOH were added, the mixture was stirred evenly, and activated at 30°C for 1 h. 1.1 moles of propylene succinic anhydride were added under a nitrogen atmosphere, the temperature was raised to 35°C, the reaction was carried out for 4 h, the mixture was distilled under reduced pressure, washed with ethyl acetate, and dried under vacuum to obtain the esterification product of alkyl glycoside and propylene succinic anhydride, which was used as the first monomer.

[0034] (2) 10 parts by mass of the first monomer obtained in step (1) and 18 parts by mass of 2-acrylamido-2-methylpropanesulfonic acid were added to a 20% volume concentration ethanol aqueous solution, mixed evenly, 0.05 parts by mass of ammonium persulfate were added, and the mixture was heated to 80°C to initiate polymerization. The reaction was carried out for 3 hours, and the pH was adjusted to 8 with 5 wt% NaOH aqueous solution. The mixture was then distilled under reduced pressure, washed with ethyl acetate, and freeze-dried to obtain an organic polymer containing glycoside units and sulfonate units.

[0035] Preparation Example 2

[0036] The other conditions are the same as those in the operation and preparation example 1, except that in step (2), the amount of 2-acrylamido-2-methylpropanesulfonic acid is 25 parts by mass.

[0037] Example

[0038] According to the formulation of the vapor phase corrosion inhibitor in Table 1, triethanolamine, borax, ammonium benzoate, sodium gluconate, sodium citrate, tryptophan, sodium aminotrimethylphosphonate, and an organic polymer containing glycoside units and sodium sulfonate were added to water in sequence and stirred until dissolved to obtain a light yellow aqueous solution. The components are expressed as a percentage by mass of the rust inhibitor aqueous solution.

[0039] Table 1 Formulation of vapor phase corrosion inhibitors

[0040]

[0041] Vapor phase corrosion inhibitor paper is a PC type (VCI + corrosion inhibitor base paper + PE film + woven fabric) corrosion inhibitor paper. Its production process consists of three stages: corrosion inhibitor preparation, lamination, and coating drying. First, the vapor phase corrosion inhibitor is prepared by adding the various corrosion inhibitor raw materials to a mixing tank containing purified water in a specific process sequence, stirring evenly at 20°C for use in the subsequent coating process. Next, lamination is performed on the corrosion inhibitor base paper carrier. PE / PP material is heated in an extruder and extruded into a film, which is then adhered between the corrosion inhibitor base paper and the woven fabric. After pressing, a composite product is formed. Finally, the laminated composite product is impregnated with vapor phase corrosion inhibitor in a coating machine, with a coating amount of 12g / m². 2 The coated composite paper becomes vapor phase rust-preventive paper material after being dried at 100℃. Figure 1 These are actual photos of the obtained rust-preventive material. Figure 2 This is a schematic diagram of the obtained rust-preventive material. Figure 1 and Figure 2 As can be seen, the rust-preventive material provided by the present invention has a multi-layer composite structure, consisting of a vapor phase rust inhibitor layer, a rust-preventive base paper layer, a polymer film layer, and a woven fabric layer. Figure 3 This is a comparison chart showing the rust-preventive effects of the rust inhibitors in Comparative Example 1 and Example 1 on galvanized aluminum-magnesium steel sheets. Figure 3The left figure shows the rust prevention effect of the rust inhibitor in Comparative Example 1, and the right figure shows the rust prevention effect of the rust inhibitor in Example 1. The rust prevention test was a 9-cycle dynamic contact damp heat test at a test temperature of 65°C.

[0042] Rust prevention performance was tested according to QB / T 1319-2010 standard, including vapor phase corrosion inhibition, vapor phase rust prevention identification test, dynamic contact damp heat test, and contact corrosion test. The test metal sheets were galvanized aluminum-magnesium steel plates. The vapor phase rust prevention identification test was conducted in a constant temperature oven, with a test cycle of 24 hours, continuously heated to 65℃, then stopped for 16 hours. The dynamic contact damp heat test was conducted in a constant temperature damp heat chamber, with a test cycle of 24 hours, continuously heated to 65℃, then stopped for 16 hours. The vapor phase corrosion inhibition test was conducted in an electrically heated blast constant temperature chamber at 40℃. In the above experiment, 100 squares of 40mm×40mm were used as a limited area. The total number of rusted squares within the effective area was the degree of rust. The rust prevention performance was determined according to the rust grading table in Table 2. The rust prevention performance was arranged into grades 0, 1, 2, 3, 4 and 5, with grade 0 representing the best rust prevention performance and grade 5 representing the worst rust prevention performance.

[0043] Table 2 Corrosion Classification Table

[0044] Rust prevention level 0 1 2 3 4 5 Corrosion 0 1-3 4-10 11-25 26-50 51-100

[0045] The results of the rust prevention test are shown in Table 3.

[0046] Table 3 Results of Rust Prevention Test

[0047]

[0048] It can be seen that the vapor phase rust inhibitor prepared by the present invention has excellent rust prevention performance, especially under high temperature conditions of 60℃, it also has satisfactory rust prevention performance.

Claims

1. A bio-based vapor phase rust inhibitor, characterized in that, Including the following ingredients by weight percentage: Triethanolamine 0.2-1 wt%, borax 2-5 wt%, ammonium benzoate 2-5 wt%, sodium gluconate 2-5 wt%, sodium citrate 1-2 wt%, tryptophan 0.05-0.2 wt%, sodium aminotrimethylphosphonate 0.5-1 wt%, organic polymers containing glycoside units and sulfonate units 1-3 wt%, balance being water.

2. The bio-based vapor phase rust inhibitor according to claim 1, characterized in that, The organic polymer containing glycoside units and sulfonate units is obtained by copolymerization of esterification products of alkyl glycosides and alkenyl succinic anhydrides with monomers containing sulfonic acid groups.

3. The bio-based vapor phase rust inhibitor according to claim 2, characterized in that, The organic polymer containing glycoside units and sulfonate units is prepared by a method comprising the following steps: (1) The alkyl glycoside is dissolved in an alcohol solvent, activated by adding an alkali, and then an alkenyl succinic anhydride is added under a protective atmosphere. The reaction is heated, distilled under reduced pressure, washed, and dried to obtain the esterification product of the alkyl glycoside and alkenyl succinic anhydride, which is used as the first monomer. (2) The first monomer obtained in step (1) and the second monomer containing sulfonic acid groups are copolymerized. After copolymerization, the pH is adjusted to 8-9 with alkaline solution to obtain an organic polymer containing glycoside units and sulfonate units.

4. The bio-based vapor phase rust inhibitor according to claim 2, characterized in that, The alkyl glycoside is a C8-C16 alkyl glycoside with a degree of polymerization of 1.1-1.7; the alkenyl succinic anhydride is selected from at least one of propenyl succinic anhydride, 2-buten-1-yl succinic anhydride, and 2-hexen-1-succinic anhydride; the monomer containing a sulfonic acid group is 2-acrylamido-2-methylpropanesulfonic acid.

5. The bio-based vapor phase rust inhibitor according to claim 4, characterized in that, The alkyl glycoside is selected from at least one of APG0810, APG1214, APG0812, APG0814, APG0816, and APG1216.

6. The bio-based vapor phase rust inhibitor according to claim 2, characterized in that, The molar ratio of alkyl glycoside to alkenyl succinic anhydride is 1:1-1.5, and the mass ratio of the esterification product of alkyl glycoside and alkenyl succinic anhydride to the monomer containing sulfonic acid group is 10:18-25.

7. The bio-based vapor phase rust inhibitor according to claim 3, characterized in that, In step (1), the alcohol solvent is selected from at least one of ethanol and isopropanol, and the amount of alcohol solvent used is 5-20 times the mass of the alkyl glycoside; the addition of alkali for activation is NaOH and / or KOH, and the amount of alkali added is 1.1-1.3 times the molar number of the alkyl glycoside, and activation is carried out at 30-40℃ for 1-2 hours; the alkenyl succinic anhydride is selected from at least one of propenyl succinic anhydride, 2-buten-1-yl succinic anhydride, and 2-hexen-1-succinic anhydride, and the molar ratio of alkyl glycoside to alkenyl succinic anhydride is 1:1-1.

5.

8. The bio-based vapor phase rust inhibitor according to claim 3, characterized in that, In step (1), the protective atmosphere is nitrogen and / or argon, and the heating reaction is to raise the temperature to 35-45°C and hold the reaction for 2-5 hours. In step (2), the copolymerization reaction conditions are as follows: the first monomer and the second monomer are added to an alcohol-water solution, an initiator is added, and the temperature is raised to initiate the copolymerization reaction; the initiator is selected from at least one of sodium persulfate, potassium persulfate, and ammonium persulfate, and the amount of initiator is 0.3-0.5 wt% of the mass of the first monomer; the temperature is raised to 80-90℃ and the polymerization time is 3-5 h.

9. The bio-based vapor phase rust inhibitor according to claim 8, characterized in that, In step (2), the alcohol-water solution is an ethanol-water solution with an ethanol volume concentration of 20-30%.

10. The bio-based vapor phase rust inhibitor according to claim 8, characterized in that, In step (2), the alkaline solution is a 5-20 wt% aqueous solution of NaOH and / or KOH. After adjusting the pH, the solution is freeze-dried to obtain a powdered product, which is an organic polymer containing glycoside units and sulfonate units.

11. A method for preparing the bio-based vapor phase rust inhibitor according to any one of claims 1-10, characterized in that, The process includes the following steps: adding triethanolamine, borax, ammonium benzoate, sodium gluconate, sodium citrate, tryptophan, sodium aminotrimethylphosphonate, and an organic polymer containing glycoside units and sodium sulfonate units to water, stirring until dissolved to obtain an aqueous solution as the vapor phase rust inhibitor.

12. The method for preparing the bio-based vapor phase rust inhibitor according to claim 11, characterized in that, Stir until dissolved. To ensure that all components of the rust inhibitor are fully dissolved, dissolve at 15–40°C.

13. A vapor phase rust inhibitor, characterized in that, Its raw materials include rust-preventive base paper, the bio-based vapor phase rust inhibitor as described in any one of claims 1-12, polymer films, and mesh or strip woven fabrics.

14. The vapor phase rust inhibitor according to claim 13, characterized in that, The vapor phase rust inhibitor is prepared by a method including the following steps: a polymer film is laminated onto one side of the rust-inhibiting base paper, then a mesh or strip woven fabric is laminated onto the polymer film, and finally the bio-based vapor phase rust inhibitor is dipped or sprayed onto the other side of the rust-inhibiting base paper, and the vapor phase rust inhibitor is obtained after drying.

15. The vapor phase corrosion inhibitor according to claim 13, characterized in that, When dipping or spraying a layer of bio-based vapor phase rust inhibitor, the dipping or spraying amount of the bio-based vapor phase rust inhibitor is 10-20 g / m². 2 .

16. The vapor phase corrosion inhibitor material according to claim 15, characterized in that, The application rate of bio-based vapor phase rust inhibitors by dip coating or spray coating is 12-15 g / m². 2 .

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