CN113234342B - Amino acid grafted graphene oxide filler, preparation method thereof and application of filler in water-based epoxy zinc-rich coating - Google Patents

Abstract

The present invention relates to a kind of amino acid grafted graphene oxide filler and its preparation method and the application in water-based epoxy zinc-rich paint, the preparation raw material of described amino acid grafted graphene oxide filler comprises: L-lysine, L-lysine Tryptophan and graphene oxide. The water-based epoxy zinc-rich coating includes: zinc powder, water-based epoxy resin, water-based epoxy curing agent, propylene glycol methyl ether, talcum powder, amino acid grafted graphene oxide filler, modifier, auxiliary agent and water. The water-based epoxy zinc-rich coating has a simple preparation process, is environmentally friendly, has good stability, strong adhesion, and has long-term anticorrosion performance, and is suitable for the field of heavy anticorrosion.

Description

A kind of amino acid grafted graphene oxide filler and its preparation method and its application in water-based epoxy Application in Zinc-rich Coatings

technical field

The invention belongs to the technical field of anti-corrosion coatings, and in particular relates to an amino acid grafted graphene oxide filler, a preparation method thereof, and an application in water-based epoxy zinc-rich coatings.

Background technique

Corrosion is a phenomenon in which metals and the surrounding environment are destroyed. The direct economic loss of about 2.5 trillion U.S. dollars in the world is caused by corrosion, which is equivalent to 3.4% of the world's GDP. In the current metal corrosion protection technology, coating protective coatings is a common method to prevent corrosion. Among different coatings, zinc-rich anti-corrosion coatings have received extensive attention. They are widely used in infrastructure construction such as ships, offshore oil platforms, storage tanks, pipelines, and bridges. They are also used in new infrastructure urban rail transit and other fields. Has good development prospects.

At present, the research on zinc-rich coatings is mainly based on solvent-based coatings. Although they have good anti-corrosion properties, they contain volatile organic substances, which are harmful to the environment and human health. The development of solvent-based zinc-rich coatings is limited. Lots of restrictions. However, water-based epoxy zinc-rich anti-corrosion coatings are more and more popular with people because of their safety, non-toxicity, environmental protection and green concepts, and have good development prospects. Therefore, in order to make waterborne epoxy zinc-rich anti-corrosion coatings widely used in the market, improving its anti-corrosion performance is the key.

CN106833271A discloses a kind of graphene type water-based epoxy zinc-rich anti-corrosion coating, described graphene-type water-based epoxy zinc-rich anti-corrosion coating is made up of A and B components, and A component is made of the following components and component percentage raw materials: Water-based epoxy resin curing agent 8-16%; defoamer 0.1-1%; dispersant 0.3-1%; thixotropic agent 0.5-3%; deionized water 3-10%; zinc powder 60-70%; graphite Alkenes 1-10%. Component B is made of the following components and component percentage raw materials: water-based epoxy emulsion 20-40%. The invention increases the adhesion and flexibility of the paint film and increases the anticorrosion performance to the base material by adding graphene. However, the compatibility between the graphene in the coating and the water-based epoxy emulsion is relatively poor, and the graphene is prone to aggregation, which makes the stability of the product relatively poor and the anti-corrosion performance is limited.

CN109554073A discloses an oil-resistant, high-efficiency and anti-corrosion water-based epoxy zinc-rich primer, including the following components by weight: water-based resin 130-190, environmental protection co-solvent 20-60, phosphorus iron powder 5-10, zinc powder 700-750 , Dispersant 5-10, defoamer 1-2, anti-flash rust additive 2-3, curing agent 60-80. The purpose of this invention is to provide a water-based epoxy zinc-rich primer with oil resistance, high efficiency and anticorrosion, which can be used to replace the solvent-based coating of the cooling oil tank of the transformer box, reduce the cost, greatly reduce the amount of solvent used, does not contain heavy metals, and is more beneficial to human health , and achieve the performance of solvent-based coatings in salt spray, adhesion, hardness, water resistance, solvent resistance and other indicators. However, the anti-corrosion performance of the primer is relatively weak.

Therefore, there is an urgent need for a water-based epoxy zinc-rich coating with simple preparation process, environmental protection, good stability, and excellent corrosion resistance and mechanical properties.

Contents of the invention

In view of the deficiencies in the prior art, the purpose of the present invention is to provide an amino acid grafted graphene oxide filler, which is energy-saving and environmentally friendly, has good stability, excellent corrosion resistance and mechanical properties, and is especially suitable for water-based epoxy zinc-rich coatings.

To achieve this purpose of the invention, the present invention adopts the following technical solutions:

In a first aspect, the present invention provides an amino acid grafted graphene oxide filler, wherein the raw materials for the preparation of the amino acid grafted graphene oxide filler include: L-lysine, L-tryptophan and graphene oxide.

The amino acid grafted graphene oxide filler involved in the present invention creatively uses L-lysine and L-tryptophan to simultaneously graft and modify graphene oxide. Or a single L-tryptophan graft modified graphene oxide has better mechanical properties and anti-corrosion properties. Among them, the side chain of L-lysine is a hydrophobic alkyl chain, which often produces a large contact angle when water contacts it, presenting a "water drop shape", which can separate the metal substrate from the corrosive medium, and the L-lysine The amino acid side chain contains a hydrophobic group indole ring, which is adsorbed on the metal through π-π interaction, and blocks the invasion of corrosive media such as water and oxygen. The present invention finds that when L-lysine, L-tryptophan At the same time, the effect of grafting and modifying graphene oxide is better than that of single L-lysine or L-tryptophan in improving the mechanical properties and anti-corrosion properties of the coating, which proves that the two have a synergistic effect.

Among them, graphene oxide is a single-layer material peeled off from graphite oxide. Due to the introduction of a large number of oxygen-containing groups on the surface and edges, it can exist stably in aqueous solutions and polar solvents. After oxidation treatment, graphite oxide remains stable. The layered structure of graphite, which can be stacked in an orderly and dense manner in the coating, forms a strong protective layer, and it has a large specific surface area, which makes the path for external corrosive media to penetrate into the surface of the steel structure complicated, improving the Penetration resistance of the coating. Graphene oxide introduces many oxygen functional groups on the graphene monolith, which improves the compatibility with water-based coatings, thereby improving the stability of the coatings.

Both L-lysine and L-tryptophan contain amino and carboxyl functional groups, and the amino groups can react with the abundant epoxy and carboxyl groups on the surface of graphene oxide, which can make graphene uniformly dispersed in water and overcome the problem of graphite oxide. After being applied to the water-based epoxy zinc-rich coating, ethylene tends to aggregate on the surface and cannot exert its own anti-corrosion performance.

Preferably, the mass ratio of the L-lysine, L-tryptophan and graphene oxide is (1-5):(1-5):3, preferably (2-4):(2-4) :3.

When the mass ratio of the L-lysine, L-tryptophan and graphene oxide is specifically selected within the above ratio range, when it is used to prepare a coating, it has more significant mechanical properties and anti-corrosion properties, and (2 -4):(2-4):3 is the range that works best.

The above (1-5) means that the specific value can be selected from 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5, etc., and other specific point values within this numerical range can be selected, so it will not be repeated here Let me repeat them one by one.

Preferably, the sheet diameter of the graphene oxide is 3-16 μm, such as 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, etc., within this numerical range Other specific point values can be selected, so I won’t go into details here.

Second aspect, the present invention provides a kind of preparation method of amino acid grafted graphene oxide filler as described in the first aspect, described preparation method comprises the steps:

(1) Mix L-lysine, L-tryptophan, sodium hydroxide and water, stir and disperse, and then ultrasonically bathe to obtain a compound amino acid solution;

(2) mixing the composite amino acid solution obtained in step (1) with graphene oxide, stirring and dispersing, then ultrasonic water bath, stirring and dispersing again to obtain a graphene oxide dispersion;

(3) Filtrating the graphene oxide dispersion obtained in step (2), washing, and drying to obtain the amino acid grafted graphene oxide filler.

The preparation process of the amino acid grafted graphene oxide filler involved in the present invention is relatively simple and easy to operate, and is very suitable for large-scale industrial production.

Preferably, the mass ratio of L-lysine, sodium hydroxide and water described in step (1) is (2-10):(1-5):(75-90), such as 2:1:75, 2 :1:80, 2:1:90, 2:5:75, 2:5:85, 2:5:90, 5:1:75, 5:1:80, 5:1:90, 10:3 :75, 10:3:90, etc.

Preferably, the stirring and dispersing in step (1) is carried out at 15-30°C (eg 15°C, 18°C, 20°C, 22°C, 25°C, 28°C, 30°C, etc.) for 0.5-2h (eg 0.5h, 0.8h, 1h, 1.2h, 1.5h, 1.8h, 2h, etc.).

Preferably, the ultrasonic water bath in step (1) is carried out at 15-30°C (eg 15°C, 18°C, 20°C, 22°C, 25°C, 28°C, 30°C, etc.) for 0.5-2h (eg 0.5h, 0.8h, 1h, 1.2h, 1.5h, 1.8h, 2h, etc.).

Preferably, the stirring and dispersing in step (2) is carried out at 50-70°C (eg 50°C, 55°C, 60°C, 62°C, 65°C, 68°C, 70°C, etc.) for 1-3h (eg 1h, 1.5 h, 2h, 2.5h, 3h, etc.).

Preferably, the ultrasonic water bath in step (2) is carried out at 50-70°C (eg 50°C, 55°C, 60°C, 62°C, 65°C, 68°C, 70°C, etc.) for 1-3h (eg 1h, 1.5 h, 2h, 2.5h, 3h, etc.).

Preferably, the stirring and dispersing in step (2) is carried out at 20-30°C (eg 20°C, 22°C, 25°C, 28°C, 30°C, etc.) for 20-30h (eg 20h, 22h, 25h, 28h , 30h, etc.).

Other specific point values within the above numerical ranges can be selected, and details will not be repeated here.

Stirring and dispersing or ultrasonic water bath in the above steps all need to meet specific temperature and time conditions. With the organic cooperation of these process parameters, the advantages of the product in terms of mechanical properties and anti-corrosion properties can be maximized.

Preferably, the filtration in step (3) is performed using a 0.22 μm polytetrafluoroethylene suction filter membrane.

Preferably, the washing in step (3) is performed using water and absolute ethanol in sequence.

Preferably, the drying in step (3) is carried out in a freeze-drying box for 25-50 hours, such as 25 hours, 28 hours, 30 hours, 32 hours, 35 hours, 38 hours, 40 hours, 45 hours, 50 hours, etc. can be selected, and will not be described in detail here.

In a third aspect, the present invention provides a water-based epoxy zinc-rich coating, which includes: zinc powder, water-based epoxy resin, water-based epoxy curing agent, propylene glycol methyl ether, talcum powder, such as the first Amino acid grafted graphene oxide filler, modifying agent, auxiliary agent and water described in aspect; Described modifying agent is any in polyvinyl alcohol, carboxymethyl cellulose, polyanionic cellulose or hydroxymethyl cellulose One or a combination of at least two.

The above-mentioned amino acid grafted graphene oxide filler is added to the water-based epoxy zinc-rich coating, and at the same time it is modified with a modifier. The two have a significant synergistic effect in improving the mechanical properties and anti-corrosion properties of the coating. .

Preferably, the water-based epoxy zinc-rich coating includes: 30-60% of zinc powder, 20-30% of water-based epoxy resin, 8-12% of water-based epoxy curing agent, 3- 6%, talc powder 1-5%, amino acid grafted graphene oxide filler 0.4-8% as described in the first aspect, modifier 0.1-2%, auxiliary agent 0.6-6%, water 5-30%.

The mass percent content of the zinc powder can be 30%, 40%, 45%, 50%, 55%, 60% and so on.

The mass percentage of the water-based epoxy resin can be 20%, 22%, 23%, 25%, 26%, 28%, 29%, 30% and so on.

The mass percent content of the water-based epoxy curing agent can be 8%, 9%, 10%, 11%, 12% and so on.

The mass percent content of the propylene glycol methyl ether may be 3%, 4%, 5%, 5.5%, 6% and so on.

The mass percent content of the talcum powder can be 1%, 2%, 3%, 4%, 5% and so on.

The mass percent content of the amino acid grafted graphene oxide filler as described in the first aspect can be 0.4%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 3%, 4%, 5%, 8%, etc.

The mass percent content of the modifying agent can be 0.1%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, etc.

The mass percentage content of the auxiliary agent can be 0.6%, 1%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6% and so on.

The mass percentage of the water may be 5%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, etc.

Other specific point values within the above numerical ranges can be selected, and details will not be repeated here.

Preferably, the auxiliary agent includes any one or a combination of at least two of thixotropic agents, film-forming aids, dispersants, defoamers, anti-flash rust agents or wetting agents; Combinations such as the combination of thixotropic agent and film-forming aid, the combination of dispersant and defoamer, the combination of anti-flash rust agent and wetting agent, etc., other arbitrary combinations can be selected, and they will not be listed one by one here. repeat.

Preferably, the epoxy equivalent of the water-based epoxy resin is 400-800, such as 400, 450, 500, 550, 600, 650, 700, 750, 800, etc. Other specific point values in this numerical range can be selected , which will not be repeated here.

Preferably, the active hydrogen equivalent of the water-based epoxy curing agent is 200-320, such as 200, 220, 250, 270, 300, 310, 320, etc. Other specific points in this numerical range can be selected, here I won't repeat them one by one.

Preferably, the particle size of the zinc powder is 3-7 μm, such as 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, etc., and the shape is spherical or flake.

In a fourth aspect, the present invention provides a method for preparing the water-based epoxy zinc-rich coating as described in the third aspect, the preparation method comprising the steps of:

(1) mixing and stirring the water-based epoxy resin and the water-based epoxy curing agent to obtain a mixture A;

(2) Mixture A and propylene glycol methyl ether are mixed and stirred to obtain mixture B;

(3) mixing mixture B with auxiliary agent, zinc powder, talcum powder and modifier to obtain mixture C;

(4) Mix and stir the mixture C, amino acid grafted graphene oxide filler, and water to adjust the viscosity of the paint to obtain the water-based epoxy zinc-rich paint.

The preparation process of the water-based epoxy zinc-rich paint involved in the present invention is relatively simple and easy to operate, and is very suitable for large-scale industrial production.

Preferably, the mixing and stirring in step (1) is carried out at 500-600r/min (such as 500r/min, 520r/min, 550r/min, 580r/min, 600r/min, etc.) for 5-15min (such as 5min, 8min, 10min, 12min, 15min, etc.).

Preferably, the mixing and stirring in step (2) is carried out at 500-600r/min (such as 500r/min, 520r/min, 550r/min, 580r/min, 600r/min, etc.) for 10-20min (such as 10min, 12min, 15min, 18min, 20min, etc.).

Preferably, the mixing and stirring in step (3) is carried out at 850-900r/min (such as 850r/min, 860r/min, 870r/min, 880r/min, 900r/min, etc.) for 30-40min (such as 30min, 32min, 35min, 38min, 40min, etc.).

Preferably, the mixing and stirring described in step (4) is carried out at 500-600r/min (such as 500r/min, 520r/min, 550r/min, 580r/min, 600r/min, etc.) for 15-25min (such as 15min, 17min, 20min, 22min, 25min, etc.).

In the fifth aspect, the present invention provides an application of the amino acid grafted graphene oxide filler as described in the first aspect and the water-based epoxy zinc-rich coating as described in the third aspect in the preparation of anti-corrosion coatings.

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

The amino acid grafted graphene oxide filler involved in the present invention creatively uses L-lysine and L-tryptophan to simultaneously graft and modify graphene oxide. Or a single L-tryptophan graft modified graphene oxide has better mechanical properties and anti-corrosion properties. Among them, the side chain of L-lysine is a hydrophobic alkyl chain, which often produces a large contact angle when water contacts it, presenting a "water drop shape", which can separate the metal substrate from the corrosive medium, and the L-lysine The amino acid side chain contains a hydrophobic group indole ring, which is adsorbed on the metal through π-π interaction, and blocks the invasion of corrosive media such as water and oxygen. The present invention finds that when L-lysine, L-tryptophan At the same time, the effect of grafting and modifying graphene oxide is better than that of single L-lysine or L-tryptophan in improving the mechanical properties and anti-corrosion properties of the coating, which proves that the two have a synergistic effect.

Among them, graphene oxide is a single-layer material peeled off from graphite oxide. Due to the introduction of a large number of oxygen-containing groups on the surface and edges, it can exist stably in aqueous solutions and polar solvents. After oxidation treatment, graphite oxide remains stable. The layered structure of graphite, which can be stacked in an orderly and dense manner in the coating, forms a strong protective layer, and it has a large specific surface area, which makes the path for external corrosive media to penetrate into the surface of the steel structure complicated, improving the Penetration resistance of the coating. Graphene oxide introduces many oxygen functional groups on the graphene monolith, which improves the compatibility with water-based coatings, thereby improving the stability of the coatings.

Both L-lysine and L-tryptophan contain amino and carboxyl functional groups, and the amino groups can react with the abundant epoxy and carboxyl groups on the surface of graphene oxide, which can make graphene uniformly dispersed in water and overcome the problem of graphite oxide. After being applied to the water-based epoxy zinc-rich coating, ethylene tends to aggregate on the surface and cannot exert its own anti-corrosion performance.

Description of drawings

Fig. 1 is the electron micrograph (12000 *) of the amino acid grafted graphene oxide filler that embodiment 1 makes.

Fig. 2 is the electron micrograph (6000 *) of the amino acid grafted graphene oxide filler that embodiment 1 makes.

Detailed ways

In order to further illustrate the technical means adopted by the present invention and its effects, the technical solutions of the present invention will be further described below in conjunction with preferred embodiments of the present invention, but the present invention is not limited within the scope of the embodiments.

The raw material information involved in the following examples, comparative examples, application examples or comparative application examples is as follows:

Graphene oxide dispersion was purchased from Nanjing Xianfeng Nano Material Technology Co., Ltd.;

Water-based epoxy resin, F0704, was purchased from Shenzhen Yoshida Chemical Co., Ltd.;

Water-based epoxy curing agent, F0704, was purchased from Shenzhen Yoshida Chemical Co., Ltd.;

Thixotropic agent, PAMID D770, purchased from Core Chemistry;

Film-forming aid, J1901, was purchased from Shenzhen Yoshida Chemical Co., Ltd.;

Dispersant, J1803, purchased from Shenzhen Yoshida Chemical Co., Ltd.;

Defoamer, J0401, purchased from Shenzhen Yoshida Chemical Co., Ltd.;

Anti-flash rust agent, FA179, purchased from Zhongshan Yongfeng Chemical Co., Ltd.;

Wetting agent, J1701, purchased from Shenzhen Yoshida Chemical Co., Ltd.;

Propylene glycol methyl ether, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.;

Talcum powder, 1250 mesh, purchased from Yongfeng Chemical Co., Ltd., Zhongshan City;

L-Tryptophan, Sinopharm Chemical Reagent Co., Ltd.;

L-Lysine, Sinopharm Chemical Reagent Co., Ltd.;

Sodium hydroxide, Sinopharm Chemical Reagent Co., Ltd.;

Polyvinyl alcohol, Shandong Chuxin Chemical Co., Ltd., model is cx336.

Example 1

This embodiment provides a kind of amino acid grafted graphene oxide filler, and its preparation method is as follows:

(1) Mix 3g of L-lysine, 3g of L-tryptophan, 2g of sodium hydroxide and 82g of water, stir and disperse at 25°C for 1h, then put in an ultrasonic water bath at 25°C for 1.5h to obtain a compound amino acid solution;

(2) Mix the compound amino acid solution obtained in step (1) with 3 g of graphene oxide powder, stir and disperse at 60°C for 2h, then ultrasonically bathe in an ultrasonic water bath for 1.5h at 60°C, and stir and disperse again at 25°C for 24h to obtain Graphene oxide dispersion;

(3) The graphene oxide dispersion obtained in step (2) is filtered using a 0.22 μm polytetrafluoroethylene suction filter membrane, washed with water and absolute ethanol in sequence, and dried in a freeze-drying box for 30 hours to obtain the amino acid The electron micrographs of the grafted graphene oxide filler are shown in Figure 1 (12000×) and Figure 2 (6000×).

Example 2

This embodiment provides a kind of amino acid grafted graphene oxide filler, and its preparation method is as follows:

(1) Mix 2 g of L-lysine, 4 g of L-tryptophan, 3 g of sodium hydroxide and 79 g of water, stir and disperse at 15°C for 2 hours, and then ultrasonically bathe for 2 hours at 15°C to obtain a compound amino acid solution;

(2) Mix the compound amino acid solution obtained in step (1) with 3 g of graphene oxide powder, stir and disperse at 50°C for 3 hours, then put in an ultrasonic water bath at 50°C for 3 hours, and stir and disperse again at 20°C for 30 hours to obtain oxidized Graphene dispersion;

(3) The graphene oxide dispersion obtained in step (2) is filtered using a 0.22 μm polytetrafluoroethylene suction filter membrane, washed with water and absolute ethanol in sequence, and dried in a freeze-drying box for 30 hours to obtain the amino acid Grafted graphene oxide filler.

Example 3

This embodiment provides a kind of amino acid grafted graphene oxide filler, and its preparation method is as follows:

(1) Mix 4g of L-lysine, 2g of L-tryptophan, 4g of sodium hydroxide and 76g of water, stir and disperse at 30°C for 0.5h, and then ultrasonically bathe for 0.5h at 30°C to obtain a compound amino acid solution ;

(2) Mix the compound amino acid solution obtained in step (1) with 3 g of graphene oxide powder, stir and disperse at 70°C for 1 hour, then put in an ultrasonic water bath at 70°C for 1 hour, stir and disperse again at 30°C for 20 hours to obtain Graphene dispersion;

(3) The graphene oxide dispersion obtained in step (2) is filtered using a 0.22 μm polytetrafluoroethylene suction filter membrane, washed with water and absolute ethanol in sequence, and dried in a freeze-drying box for 30 hours to obtain the amino acid Grafted graphene oxide filler.

Example 4

This embodiment provides a kind of amino acid grafted graphene oxide filler, the difference between its preparation method and embodiment 1 is that the quality of L-lysine in step (1) is 5g, the quality of L-tryptophan is 1g, All other conditions remain unchanged.

Example 5

This embodiment provides a kind of amino acid grafted graphene oxide filler, the difference between its preparation method and embodiment 1 is that the quality of L-lysine in step (1) is 1g, the quality of L-tryptophan is 5g, All other conditions remain unchanged.

Comparative example 1

This comparative example provides a kind of amino acid grafted graphene oxide filler, the difference of its preparation method and embodiment 1 is that step (1) does not contain L-lysine, and the quality of L-tryptophan is 6g, other Conditions remain the same.

Comparative example 2

This comparative example provides a kind of amino acid grafted graphene oxide filler, the difference of its preparation method and embodiment 1 is that step (1) does not contain L-tryptophan, and the quality of L-lysine is 6g, other Conditions remain the same.

Comparative example 3

This comparative example provides a graphene oxide filler without graft modification.

Application example 1

This application example provides a water-based epoxy zinc-rich coating, including: zinc powder 60g, water-based epoxy resin 44g, water-based epoxy curing agent 20g, propylene glycol methyl ether 10g, talcum powder 5g, Example 1 Prepared amino acid grafted graphene oxide filler 5g, polyvinyl alcohol 3g, thixotropic agent 1.5g, dispersant 1.5g, film-forming aid 1.5g, defoamer 1.5g, anti-flash rust agent 0.5g, wetting Agent 0.75g, water 20g.

Its preparation method is as follows:

(1) Mix and stir the water-based epoxy resin and the water-based epoxy curing agent at 550r/min for 10min to obtain a mixture A;

(2) Mixture A and propylene glycol methyl ether were mixed and stirred at 550r/min for 15min to obtain mixture B;

(3) Mix mixture B with various additives, zinc powder, talcum powder, and polyvinyl alcohol at 850r/min and stir for 35min to obtain mixture C;

(4) Mix mixture C and the water dispersion of amino acid grafted graphene oxide filler at 550 r/min for 20 minutes, adjust the viscosity of the paint to apply three cups for 12 seconds, and obtain the water-based epoxy zinc-rich paint.

Application example 2-5

This application example provides four kinds of water-based epoxy zinc-rich coatings. Compared with application example 1, its components differ only in that the amino acid grafted graphene oxide filler prepared in example 1 is replaced with the one prepared in example 2-5. Amino acid grafted graphene oxide filler, other conditions remain unchanged.

Comparative application examples 1-3

This application example provides three kinds of water-based epoxy zinc-rich coatings. Compared with application example 1, its components differ only in that the amino acid grafted graphene oxide filler prepared in example 1 is replaced by the one prepared in comparative example 1-3. Graphene oxide filler, other conditions remain unchanged.

Comparative application example 4

This application example provides a kind of water-based epoxy zinc-rich coating, its component is compared with application example 1 and its difference is only to not contain polyvinyl alcohol, and the amino acid grafted graphene oxide filler that embodiment 1 makes is 8g, other Conditions remain the same.

Comparative application example 5

This application example provides a kind of water-based epoxy zinc-rich coating, its composition is compared with application example 1, and its difference is only that it does not contain the amino acid grafted graphene oxide filler that embodiment 1 makes, and polyvinyl alcohol is 8g, other Conditions remain the same.

Comparative application example 6

This application example provides a water-based epoxy zinc-rich coating. Compared with application example 1, its components differ only in that it does not contain the amino acid grafted graphene oxide filler prepared in example 1, and other conditions remain unchanged.

Performance Testing:

The water-based epoxy zinc-rich paint prepared in Application Examples 1-5 and Comparative Application Examples 1-6 was coated on the surface of the sandblasted steel plate substrate to obtain an anti-corrosion coating with a thickness of 110 μm. According to the industry standard "Graphene Zinc Powder Coating" (HG/T 5573-2019), the following performance tests are carried out on the coating:

The content of non-volatile matter shall be carried out according to the provisions of GB/T 1725-2007.

Impact resistance, according to the provisions of GB/T 1732-2020.

Adhesion, according to the provisions of GB/T 5210-2006.

Neutral salt spray test, according to the provisions of GB/T 1771-2007 and GB/T 1766-2008.

The results are shown in Table 1 (each group was tested 3 times in parallel and averaged):

Table 1

From the data in Table 1, it can be seen that when the amino acid grafted graphene oxide filler involved in the present invention is applied in a coating, it has better mechanical properties than a single L-lysine or a single L-tryptophan grafted modified graphene oxide and anti-corrosion properties, and when the amino acid grafted graphene oxide filler is used together with a modifier, the two have a significant synergistic effect in improving the mechanical properties and anti-corrosion properties of the coating.

The applicant declares that the present invention illustrates a kind of amino acid grafted graphene oxide filler of the present invention and its preparation method and application in water-based epoxy zinc-rich coatings through the above examples, but the present invention is not limited to the above examples , that is, it does not mean that the present invention can only be implemented depending on the above-mentioned embodiments. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the scope of protection and disclosure of the present invention.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention. These simple modifications All belong to the protection scope of the present invention.

In addition, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way if there is no contradiction. The combination method will not be described separately.

Claims (25)

1. A water-based epoxy zinc-rich paint, characterized in that, the water-based epoxy zinc-rich paint comprises: zinc powder, water-based epoxy resin, water-based epoxy curing agent, propylene glycol methyl ether, talcum powder, amino acid graft oxidation Graphene fillers, modifiers, additives and water; The modifier is any one or a combination of at least two of polyvinyl alcohol, carboxymethyl cellulose, polyanionic cellulose or hydroxymethyl cellulose; the raw material for the preparation of the amino acid grafted graphene oxide filler Includes: L-Lysine, L-Tryptophan and Graphene Oxide. 2. water-based epoxy zinc-rich paint as claimed in claim 1, is characterized in that, the mass ratio of described L-lysine, L-tryptophan and graphene oxide is (1-5): (1- 5): 3. 3. water-based epoxy zinc-rich paint as claimed in claim 1, is characterized in that, the mass ratio of described L-lysine, L-tryptophan and graphene oxide is (2-4): (2- 4): 3. 4. The water-based epoxy zinc-rich paint as claimed in claim 1, wherein the sheet diameter of the graphene oxide is 3-16 μm. 5. water-based epoxy zinc-rich paint as claimed in claim 1, is characterized in that, the preparation method of described amino acid grafted graphene oxide filler comprises the steps: (1) Mix L-lysine, L-tryptophan, sodium hydroxide and water, stir and disperse, and then ultrasonically bathe to obtain a compound amino acid solution; (2) mixing the composite amino acid solution obtained in step (1) with graphene oxide, stirring and dispersing, then ultrasonic water bath, stirring and dispersing again, to obtain a graphene oxide dispersion; (3) Filtrating the graphene oxide dispersion obtained in step (2), washing, and drying to obtain the amino acid grafted graphene oxide filler. 6. water-based epoxy zinc-rich paint as claimed in claim 5, is characterized in that, the mass ratio of L-lysine described in step (1), sodium hydroxide and water is (6-15): (2- 5): (75-90). 7. The water-based epoxy zinc-rich paint according to claim 5, characterized in that the stirring and dispersing in step (1) is carried out at 15-30°C for 0.5-2h. 8 . The water-based epoxy zinc-rich coating according to claim 5 , wherein the ultrasonic water bath in step (1) is carried out at 15-30° C. for 0.5-2 h. 9. The water-based epoxy zinc-rich coating according to claim 5, characterized in that, the stirring and dispersing in step (2) is carried out at 50-70°C for 1-3h. 10. The water-based epoxy zinc-rich coating according to claim 5, characterized in that the ultrasonic water bath in step (2) is carried out at 50-70°C for 1-3h. 11. The water-based epoxy zinc-rich coating according to claim 5, characterized in that, the stirring and dispersing in step (2) is carried out at 20-30° C. for 20-30 h. 12. The water-based epoxy zinc-rich paint as claimed in claim 5, characterized in that, the filtration in step (3) uses a 0.22 μm polytetrafluoroethylene suction filter membrane to filter. 13. The water-based epoxy zinc-rich paint as claimed in claim 5, wherein the washing in step (3) uses water and absolute ethanol to wash in sequence. 14. The water-based epoxy zinc-rich paint as claimed in claim 5, characterized in that, the drying in step (3) is carried out in a freeze-drying oven for 25-50 hours. 15. The water-based epoxy zinc-rich paint as claimed in claim 1, characterized in that, the water-based epoxy zinc-rich paint comprises: 30-60% of zinc powder, 20-30% of water-based epoxy resin %, water-based epoxy curing agent 8-12%, propylene glycol methyl ether 3-6%, talcum powder 1-5%, amino acid grafted graphene oxide filler 0.4-8%, modifier 0.1-2%, additive 0.6 -6%, water 5-30%. 16. The water-based epoxy zinc-rich paint as claimed in claim 1, wherein said auxiliary agent comprises thixotropic agent, film-forming aid, dispersant, defoamer, anti-flash rust agent or wetting agent any one or a combination of at least two. 17. The water-based epoxy zinc-rich coating according to claim 1, wherein the epoxy equivalent of the water-based epoxy resin is 400-800. 18. The water-based epoxy zinc-rich coating according to claim 1, wherein the active hydrogen equivalent of the water-based epoxy curing agent is 200-320. 19. The water-based epoxy zinc-rich paint according to claim 1, characterized in that, the particle size of the zinc powder is 3-7 μm, and the shape is spherical or flake. 20. the preparation method of the waterborne epoxy zinc-rich coating as described in any one in claim 1-19, is characterized in that, described preparation method comprises the steps: (1) mixing and stirring the water-based epoxy resin and the water-based epoxy curing agent to obtain a mixture A; (2) mixing and stirring mixture A and propylene glycol methyl ether to obtain mixture B; (3) mixing mixture B with auxiliary agent, zinc powder, talcum powder and modifier to obtain mixture C; (4) Mix and stir the mixture C, amino acid grafted graphene oxide filler, and water to adjust the viscosity of the paint to obtain the water-based epoxy zinc-rich paint. 21. The preparation method of waterborne epoxy zinc-rich paint as claimed in claim 20, is characterized in that, the described mixing and stirring of step (1) is carried out 5-15min at 500-600r/min. 22. The preparation method of waterborne epoxy zinc-rich paint as claimed in claim 20, is characterized in that, the described mixing and stirring of step (2) is carried out 10-20min at 500-600r/min. 23. The preparation method of waterborne epoxy zinc-rich paint as claimed in claim 20, is characterized in that, the described mixing and stirring of step (3) is carried out 30-40min at 850-900r/min. 24. The preparation method of waterborne epoxy zinc-rich paint as claimed in claim 20, is characterized in that, the described mixing and stirring of step (4) is carried out 15-25min at 500-600r/min. 25. the application in the preparation anticorrosion coating of waterborne epoxy zinc-rich coating as described in any one in claim 1-19.

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