Shallow sea island anticorrosive paint and preparation method thereof

Abstract

The invention discloses a shallow sea island anticorrosive paint and a preparation method thereof, and relates to the technical field of anticorrosive paints.The preparation method comprises the following preparation steps that firstly, aminated graphene oxide dispersion liquid and aniline salt solution are mixed, then ammonium persulfate solution is slowly dropwise added, stirring reaction is conducted at the constant speed under the ice bath condition of 0-5 DEG C, washing is conducted after the reaction is completed, and a graphene oxide precursor is obtained; the preparation method comprises the following steps: adding graphene oxide into a reaction kettle, carrying out suction filtration until filtrate is neutral, carrying out vacuum drying at 65 DEG C for 42-48 hours, then putting the reaction kettle into an N, N-dimethylformamide solution, soaking and washing at 90 DEG C for 40-45 hours, then washing for 3-4 times by adopting absolute ethyl alcohol, and then carrying out vacuum drying at 65 DEG C for 42-48 hours, so as to prepare the grafted modified graphene oxide. According to the shallow sea island anticorrosive paint and the preparation method thereof, 4, 4-diphenylmethane diisocyanate and 1, 4-butanediol are subjected to a cross-linking reaction under the action of epoxy resin and dibutyltin laurate, so that a formed polymer network structure is more compact, and the hardness and wear resistance of a coating are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of anti-corrosion coatings, in particular to an anti-corrosion coating for shallow islands and reefs and a preparation method thereof. Background Art

[0002] Referring to the Chinese patent fluorosilicone type heat-insulating, weather-resistant and anti-corrosion coating for steel substrate of island and reef engineering and its preparation method (Announcement No.: CN111218171A), it includes a main agent and a curing agent, and the ratio of the main agent to the curing agent is 10:1, wherein: the main agent includes the following formula in parts by mass: 36-40 parts of fluorocarbon resin, 8-10 parts of silicone resin, 13-16 parts of mixed solvent, 25-28 parts of functional filler, 16-20 parts of pigment and filler, 0.2-0.3 parts of salt spray resistant additive, 0.3-0.4 parts of aging resistant additive, 0.2-0.3 parts of anti-ultraviolet absorber, 0.3-0.4 parts of defoaming agent, 0.3-0.4 parts of leveling agent, and 0.3-0.4 parts of wetting and dispersing agent. The coating of the present invention has a solid content of ≥75%, a light specific gravity, and good coating processability. It can be used in conjunction with commonly used epoxy primers, epoxy micaceous iron intermediates, epoxy glass flake primers, midcoats, epoxy zinc-rich primers, and inorganic zinc-rich primers. It exhibits excellent salt spray and aging resistance, as well as thermal insulation properties, offering a high cost-effectiveness and facilitating widespread application. However, the anti-corrosion properties of the resin in this patent could be further enhanced; to this end, the present invention proposes an anti-corrosion coating for shallow islands and reefs and a preparation method to address these issues. Summary of the Invention

[0003] (1) Technical problems solved

[0004] In view of the deficiencies in the prior art, the present invention provides an anti-corrosion coating for shallow islands and reefs and a preparation method thereof, which solves the problems mentioned in the above background technology.

[0005] (2) Technical solution

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a shallow island and reef anti-corrosion coating, which includes 85-100 parts by weight of a terpolymer, 20-40 parts by weight of grafted modified graphene oxide, and 15-30 parts by weight of a rust remover.

[0007] A method for preparing an anti-corrosion coating for shallow islands and reefs, comprising the following steps:

[0008] Step 1: Mix the aminated graphene oxide dispersion with the aniline salt solution, then slowly dropwise add the ammonium persulfate solution, and stir the mixture at a constant speed under an ice bath condition of 0-5°C. After the reaction is completed, wash, filter until the filtrate is neutral, vacuum dry at 65°C for 42-48h, and then place in N,N-dimethylformamide solution, soak and wash at 90°C for 40-45h, wash with anhydrous ethanol 3-4 times, and then vacuum dry at 65°C for 42-48h to obtain grafted modified graphene oxide;

[0009] Step 2: Add N,N-dimethylformamide to the polylactic acid-glycolic acid copolymer at 80°C, and after it is completely dissolved, add 4,4 ， -diphenylmethane diisocyanate, stirring and reacting for 50-60 minutes, cooling to room temperature, adding 1,4-butanediol, mixing evenly, adding epoxy resin and dibutyltin laurate, heating to 85°C, reacting for 3 hours, cooling to room temperature, mixing with methylhexahydrophthalic anhydride, adding defoamer and leveling agent, and magnetic stirring at a speed of 800-1000 r / min for 5-10 minutes to obtain a terpolymer;

[0010] Step 3: Add grafted modified graphene oxide and rust-removing agent to the ternary copolymer in sequence, stir and disperse in a high-speed shear emulsifier to obtain shallow sea island and reef anti-corrosion coating.

[0011] Preferably, in step 1, the amount of the aminated graphene oxide dispersion is 5-10 parts by weight, the amount of the aniline salt solution is 15-25 parts by weight, the amount of the ammonium persulfate solution is 3-6 parts by volume, and the amount of the N,N-dimethylformamide solution is 30-40 parts by volume.

[0012] Preferably, in the step 2, the polylactic acid-glycolic acid copolymer is 0.8-2 parts by weight, 4,4 ， -diphenylmethane diisocyanate is 0.06-0.18 parts by weight, epoxy resin is 25-40 parts by weight, dibutyltin laurate is 3-4 parts by weight, methylhexahydrophthalic anhydride is 3-3.6 parts by weight, defoamer is 0.3-0.8 parts by weight, leveling agent is 0.3-0.6 parts by weight, N,N-dimethylformamide is 15-20 parts by volume, and 1.4-butanediol is 12-15 parts by volume.

[0013] Preferably, the preparation of the aminated graphene oxide dispersion is as follows: 4 g of graphene oxide is poured into a 250 mL autoclave, and the autoclave is filled with concentrated ammonia water, stirred and reacted at 45 ° C for 10 hours, and after the reaction is completed, cooled to room temperature, filtered, washed with distilled water until neutral, and vacuum dried at 50 ° C for 24 hours to obtain aminated graphene oxide, and then 2 g of the dried aminated graphene oxide is poured into 30 mL of deionized water, and ultrasonically dispersed for 30 minutes to obtain an aminated graphene oxide dispersion.

[0014] Preferably, the aniline salt solution is prepared by adding 30 mL of 2 mol / L hydrochloric acid solution to 2-3.5 g of aniline, stirring and reacting for 30 minutes to obtain the aniline salt solution.

[0015] Preferably, in step 1, the uniform stirring speed is 400-500 r / min, and the stirring reaction time is 10-12 h.

[0016] Preferably, the preparation of the rust-removing agent is:

[0017] (1) At room temperature, mix gallic acid with 5g of deionized water and stir for 15-25min to obtain component A;

[0018] (2) At room temperature, pour phosphoric acid and penetrant into 5g of deionized water and stir for 20-30 minutes to obtain component B;

[0019] (3) Place component A and component B in a constant temperature water bath at 40°C and stir to react to obtain a rust remover.

[0020] Preferably, the mass of the phosphoric acid is 50%-70% of the mass of gallic acid; in (3), the stirring speed is 2500-3000 r / min, and the stirring reaction time is 20-30 min.

[0021] (3) Beneficial effects

[0022] The present invention provides a shallow island reef anti-corrosion coating and a preparation method thereof. Compared with the prior art, the shallow island reef anti-corrosion coating and the preparation method thereof have the following beneficial effects: ， -Diphenylmethane diisocyanate and 1,4-butanediol undergo a cross-linking reaction under the action of epoxy resin and dibutyltin laurate, making the formed polymer network structure denser, thereby improving the hardness and wear resistance of the coating; the coating formed by the terpolymer can prevent external corrosive substances such as oxygen, moisture, and salt from contacting the metal surface. The gallic acid in the rust remover can undergo a complexation or chelation reaction with rust, converting the rust into a stable substance and preventing further spread of rust; phosphoric acid reacts with the metal surface to form a phosphate protective film, enhancing the corrosion resistance of the metal; the grafted modified graphene oxide acts as a physical barrier in the coating due to its own two-dimensional flaky structure, requiring corrosive substances to travel a longer path to reach the metal surface, slowing down the corrosion rate. At the same time, its good compatibility with the terpolymer ensures the effectiveness of this barrier effect, thereby effectively improving the anti-corrosion performance of the coating. DETAILED DESCRIPTION

[0023] The following is a clear and complete description of 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 making any creative efforts are within the scope of protection of the present invention.

[0024] In this application, the defoaming agent is TEGO Foamex 810; the leveling agent is BYK-306.

[0025] Poly(lactic-co-glycolic acid): Shandong Daigang Biotechnology Co., Ltd.

[0026] 4,4 ， -Diphenylmethane diisocyanate: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0027] Epoxy resin: E-44, Jiangsu Sanmu Group Co., Ltd.

[0028] Preparation of aminated graphene oxide dispersion: 4 g of graphene oxide was poured into a 250 mL autoclave, and concentrated ammonia was added to the autoclave. The mixture was stirred and reacted at 45°C for 10 h. After the reaction was completed, it was cooled to room temperature, filtered, washed with distilled water until neutral, and vacuum dried at 50°C for 24 h to obtain aminated graphene oxide. Then 2 g of the dried aminated graphene oxide was poured into 30 mL of deionized water and ultrasonically dispersed for 30 min to obtain an aminated graphene oxide dispersion.

[0029] The preparation method of the aniline salt solution is as follows: 30 mL of 2 mol / L hydrochloric acid solution is added to 2 g of aniline, and the mixture is stirred and reacted for 30 minutes to obtain the aniline salt solution.

[0030] Example 1

[0031] Step 1: 5 g of aminated graphene oxide dispersion was mixed with 15 g of aniline salt solution, and then 3 mL of ammonium persulfate solution was slowly added dropwise. The mixture was stirred at a speed of 400 r / min under an ice bath condition of 0 ° C for 10 h. After the reaction was completed, it was washed, filtered until the filtrate was neutral, vacuum dried at 65 ° C for 42 h, and then placed in 30 mL of N, N-dimethylformamide solution. After soaking and washing at 90 ° C for 40 h, it was washed three times with anhydrous ethanol and then vacuum dried at 65 ° C for 42 h to obtain grafted modified graphene oxide;

[0032] Step 2: Add 15 mL of N, N-dimethylformamide to 0.8 g of poly(lactic acid-co-glycolic acid) at 80 °C. After the mixture is completely dissolved, add 0.06 g of 4,4 ，-diphenylmethane diisocyanate, stirred and reacted for 50 minutes, cooled to room temperature, and then 12 mL of 1.4-butanediol was added and mixed evenly. Then, 25 g of epoxy resin and 3 g of dibutyltin laurate were added. The temperature was raised to 85°C and reacted for 3 hours. After that, the mixture was cooled to room temperature and mixed with 3 g of methylhexahydrophthalic anhydride. 0.3 g of defoamer and 0.3 g of leveling agent were added. The mixture was magnetically stirred at a speed of 800 r / min for 5 minutes to obtain a terpolymer.

[0033] Preparation of a rust remover: 2 g of gallic acid and 5 g of deionized water were mixed and stirred at room temperature for 15 minutes to obtain component A. 1 g of phosphoric acid and a penetrant were poured into 5 g of deionized water at room temperature and stirred for 20 minutes to obtain component B. Components A and B were placed in a constant temperature water bath at 40°C and stirred at 2500 rpm for 20 minutes to obtain a rust remover.

[0034] Step 3: Add 40g of grafted modified graphene oxide and 30g of rust-removing agent to 85g of terpolymer in sequence, stir and disperse in a high-speed shear emulsifier to obtain shallow sea island and reef anti-corrosion coating.

[0035] Example 2

[0036] Step 1: 8 g of aminated graphene oxide dispersion was mixed with 20 g of aniline salt solution, and then 5 mL of ammonium persulfate solution was slowly added dropwise. The mixture was stirred at a speed of 450 r / min under an ice bath at 2 ° C for 11 h. After the reaction was completed, the mixture was washed, filtered until the filtrate was neutral, vacuum dried at 65 ° C for 45 h, and then placed in 35 mL of N, N-dimethylformamide solution. After soaking and washing at 90 ° C for 42 h, it was washed three times with anhydrous ethanol and then vacuum dried at 65 ° C for 45 h to obtain grafted modified graphene oxide;

[0037] Step 2: Add 18 mL of N, N-dimethylformamide to 1.4 g of poly(lactic acid-co-glycolic acid) at 80 °C. After complete dissolution, add 0.12 g of 4,4 ， -diphenylmethane diisocyanate, stirred and reacted for 55 minutes, cooled to room temperature, and then 14 mL of 1.4-butanediol was added and mixed evenly. Then, 30 g of epoxy resin and 3.5 g of dibutyltin laurate were added. The temperature was raised to 85 ° C. and reacted for 3 hours. After cooling to room temperature, 3.3 g of methylhexahydrophthalic anhydride was mixed, and 0.5 g of defoamer and 0.5 g of leveling agent were added. The mixture was magnetically stirred at a speed of 900 r / min for 8 minutes to obtain a terpolymer;

[0038] Preparation of a rust remover: 2 g of gallic acid and 5 g of deionized water were mixed and stirred at room temperature for 20 minutes to obtain component A. 1.2 g of phosphoric acid and a penetrant were poured into 5 g of deionized water at room temperature and stirred for 25 minutes to obtain component B. Components A and B were placed in a constant temperature water bath at 40°C and stirred at 2800 rpm for 25 minutes to obtain a rust remover.

[0039] Step 3: Add 30g of grafted modified graphene oxide and 20g of rust-removing agent to 90g of terpolymer in sequence, stir and disperse in a high-speed shear emulsifier to obtain shallow sea island and reef anti-corrosion coating.

[0040] Example 3

[0041] Step 1: 10 g of aminated graphene oxide dispersion was mixed with 25 g of aniline salt solution, and then 6 mL of ammonium persulfate solution was slowly added dropwise. The mixture was stirred at a speed of 500 r / min under an ice bath at 5 ° C for 12 h. After the reaction was completed, it was washed and filtered until the filtrate was neutral. It was vacuum-dried at 65 ° C for 48 h, and then placed in 40 mL of N, N-dimethylformamide solution. After soaking and washing at 90 ° C for 45 h, it was washed 4 times with anhydrous ethanol and then vacuum-dried at 65 ° C for 48 h to obtain grafted modified graphene oxide;

[0042] Step 2: Add 20 mL of N, N-dimethylformamide to 2 g of poly(lactic acid-co-glycolic acid) at 80 °C. After the mixture is completely dissolved, add 0.18 g of 4,4 ， -diphenylmethane diisocyanate, stirred and reacted for 60 minutes, cooled to room temperature, and then 15 mL of 1.4-butanediol was added and mixed evenly. Then, 40 g of epoxy resin and 4 g of dibutyltin laurate were added. The temperature was raised to 85°C and reacted for 3 hours. After that, the mixture was cooled to room temperature and mixed with 3.6 g of methylhexahydrophthalic anhydride. 0.8 g of defoamer and 0.6 g of leveling agent were added. The mixture was magnetically stirred at a speed of 1000 r / min for 10 minutes to obtain a terpolymer.

[0043] Preparation of a rust remover: 2 g of gallic acid and 5 g of deionized water were mixed and stirred at room temperature for 25 minutes to obtain component A. 1.4 g of phosphoric acid and a penetrant were poured into 5 g of deionized water at room temperature and stirred for 30 minutes to obtain component B. Components A and B were placed in a constant temperature water bath at 40°C and stirred at 3000 rpm for 30 minutes to obtain a rust remover.

[0044] Step 3: Add 20g of grafted modified graphene oxide and 15g of rust-removing agent to 100g of the terpolymer in sequence, stir and disperse in a high-speed shear emulsifier to obtain a shallow island reef anti-corrosion coating.

[0045] Comparative Example 1

[0046] Compared with Example 1, the difference is that the grafted modified graphene oxide is not added; the rest remains unchanged.

[0047] Comparative Example 2

[0048] Compared with Example 1, the difference is that no rust-removing agent is added; the rest remains unchanged.

[0049] Comparative Example 3

[0050] Compared with Example 1, the difference is that the terpolymer is replaced by epoxy resin (E-44); the rest remains unchanged.

[0051] The coating was sprayed onto the tinplate surface and cured at 90°C for 2 hours and then at 120°C for 3 hours. Salt spray resistance was tested according to GB / T 1771-2007. Friction mass loss and abrasion resistance were tested according to GB / T 1768-2006. Pencil hardness was tested according to GB / T 6739-2022.

[0052] Salt spray resistance (2000h) Friction mass loss (mg) Pencil hardness Example 1 No blistering, no rust 44.7 5H Example 2 No blistering, no rust 38.9 6H Example 3 No blistering, no rust 33.2 6H Comparative Example 1 Bubbling, no rust 64.6 3H Comparative Example 2 Blistering, rust 61.2 4H Comparative Example 3 Blistering, rust 74.3 3H

[0053] At the same time, the contents not described in detail in this specification belong to the existing technology well known to those skilled in the art.

[0054] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0055] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An anti-corrosion coating for shallow islands and reefs, characterized in that: The shallow island and reef anti-corrosion coating comprises 85-100 parts by weight of a terpolymer, 20-40 parts by weight of grafted modified graphene oxide, and 15-30 parts by weight of a rust-removing agent.

2. A method for preparing the shallow island and reef anticorrosive coating according to claim 1, characterized in that: The method comprises the following preparation steps: Step 1: Mix the aminated graphene oxide dispersion with the aniline salt solution, then slowly dropwise add the ammonium persulfate solution, and stir the mixture at a constant speed under an ice bath condition of 0-5°C. After the reaction is completed, wash, filter until the filtrate is neutral, vacuum dry at 65°C for 42-48h, and then place in N,N-dimethylformamide solution, soak and wash at 90°C for 40-45h, wash with anhydrous ethanol 3-4 times, and then vacuum dry at 65°C for 42-48h to obtain grafted modified graphene oxide; Step 2: Add N,N-dimethylformamide to the polylactic acid-glycolic acid copolymer at 80°C, and after it is completely dissolved, add 4,4 ， -diphenylmethane diisocyanate, stirring and reacting for 50-60 minutes, cooling to room temperature, adding 1,4-butanediol, mixing evenly, adding epoxy resin and dibutyltin laurate, heating to 85°C, reacting for 3 hours, cooling to room temperature, mixing with methylhexahydrophthalic anhydride, adding defoamer and leveling agent, and magnetic stirring at a speed of 800-1000 r / min for 5-10 minutes to obtain a terpolymer; Step 3: Add grafted modified graphene oxide and rust-removing agent to the terpolymer in sequence, stir and disperse in a high-speed shear emulsifier to obtain shallow sea island and reef anti-corrosion coating.

3. The method for preparing a shallow island and reef anticorrosive coating according to claim 2, characterized in that: In the step 1, the amount of the aminated graphene oxide dispersion is 5-10 parts by weight, the amount of the aniline salt solution is 15-25 parts by weight, the amount of the ammonium persulfate solution is 3-6 parts by volume, and the amount of the N,N-dimethylformamide solution is 30-40 parts by volume.

4. The method for preparing a shallow island and reef anticorrosive coating according to claim 2, characterized in that: In the step 2, the polylactic acid-glycolic acid copolymer is 0.8-2 parts by weight, 4,4 ， -diphenylmethane diisocyanate is 0.06-0.18 parts by weight, epoxy resin is 25-40 parts by weight, dibutyltin laurate is 3-4 parts by weight, methylhexahydrophthalic anhydride is 3-3.6 parts by weight, defoamer is 0.3-0.8 parts by weight, leveling agent is 0.3-0.6 parts by weight, N,N-dimethylformamide is 15-20 parts by volume, and 1.4-butanediol is 12-15 parts by volume.

5. The method for preparing a shallow island and reef anticorrosive coating according to claim 2, characterized in that: Preparation of the aminated graphene oxide dispersion: 4 g of graphene oxide is poured into a 250 mL autoclave, and concentrated ammonia is added to the autoclave, and the reaction is stirred at 45° C. for 10 hours. After the reaction is completed, it is cooled to room temperature, filtered, washed with distilled water until neutral, and vacuum dried at 50° C. for 24 hours to obtain the aminated graphene oxide. Then, 2 g of the dried aminated graphene oxide is poured into 30 mL of deionized water, and ultrasonically dispersed for 30 minutes to obtain the aminated graphene oxide dispersion.

6. The method for preparing a shallow island and reef anticorrosive coating according to claim 2, characterized in that: The preparation method of the aniline salt solution is as follows: 30 mL of 2 mol / L hydrochloric acid solution is added to 2-3.5 g of aniline, and the mixture is stirred for reaction for 30 minutes to obtain the aniline salt solution.

7. The method for preparing a shallow island and reef anticorrosive coating according to claim 2, characterized in that: In the step 1, the uniform stirring speed is 400-500 r / min, and the stirring reaction time is 10-12 h.

8. The method for preparing a shallow island and reef anticorrosive coating according to claim 2, characterized in that: Preparation of the rust-removing agent: (1) At room temperature, mix gallic acid with 5g of deionized water and stir for 15-25min to obtain component A; (2) At room temperature, pour phosphoric acid and penetrant into 5g of deionized water and stir for 20-30 minutes to obtain component B; (3) Component A and component B are placed in a constant temperature water bath at 40°C and stirred to react to obtain a rust remover.

9. The method for preparing an anti-corrosion coating for shallow islands and reefs according to claim 8, characterized in that: The mass of the phosphoric acid is 50%-70% of the mass of the gallic acid; in (3), the stirring speed is 2500-3000 r / min, and the stirring reaction time is 20-30 min.