CN118085677A - Solvent-free graphene metal anticorrosive paint and preparation method thereof - Google Patents

Abstract

The invention discloses a solvent-free graphene metal anti-corrosion coating and a preparation method thereof. Low-viscosity solvent-free epoxy resin, reactive diluent and modified amine are used as base materials, metal abrasive is added to enhance the anti-corrosion ability, and 100% liquid petroleum resin is added to improve the construction period and achieve the effect of normal temperature construction. Graphene is added to achieve stronger shielding and corrosion resistance. The prepared coating has strong anti-corrosion ability, strong adhesion, high hardness, wear resistance, salt spray resistance, and a solid content greater than 99.5%.

Description

A solvent-free graphene metal anti-corrosion coating and preparation method thereof

Technical Field

The invention relates to an anticorrosion coating in the field of industrial heavy corrosion protection, in particular to a solvent-free graphene metal anticorrosion coating and a preparation method thereof.

Background technique

At present, global environmental awareness is gradually increasing, and government policies and regulations are constantly being strengthened, which has promoted the development of the environmental protection industry. At present, solvent-free coatings, as environmentally friendly products, are favored by the market. It is expected that the market size and share will continue to expand in the next few years.

In the industrial anti-corrosion industry, since no diluent is added during the production process, the viscosity of the product is too high. Therefore, the construction of most solvent-free products still relies on professional construction equipment. This set of equipment is not only expensive, but also complicated to operate and has a high threshold. It requires the coordination of electricity, gas and other conditions, and requires professional personnel to operate, which is not conducive to the promotion of solvent-free products.

Solvent-free epoxy coatings also have limitations, such as average salt spray resistance, short construction period, and brittle paint film. These problems have led to a reduction in the application scenarios of solvent-free epoxy coatings. In the above, we need to develop a solvent-free epoxy product that can be applied at room temperature, is not limited by construction equipment, and has excellent corrosion resistance.

Summary of the invention

Purpose of the invention: The technical problem to be solved by the present invention is to provide a solvent-free graphene metal anti-corrosion coating in view of the deficiencies in the prior art. The solvent-free coating of the present invention has excellent anti-corrosion ability, can be normally constructed at room temperature and is not limited to roller coating, brush coating, and spray coating, and has a construction period of more than 3 hours.

In order to solve the above technical problems, the present invention provides a solvent-free graphene metal anti-corrosion coating, comprising component A and component B, wherein by weight:

Component A is 15-35 parts of epoxy resin, 5-15 parts of petroleum resin, 0.5-1.5 parts of dispersant, 0.5-1.5 parts of rheological additive, 0.1-0.6 parts of defoamer, 10-20 parts of filler, 10-30 parts of zinc powder, 5-15 parts of aluminum powder, 5-10 parts of active diluent; 1-5 parts of graphene slurry;

Component B is 90-95 parts of epoxy curing agent and 5-10 parts of accelerator;

The epoxy resin is an E51 bisphenol A epoxy resin with 100% solid content and a viscosity of 8000-10000 mPa.s. Preferably, Miki SM827H is selected; the petroleum resin is a polybutadiene with an effective component of 99.9%. Preferably, Crayville Ricon300 is selected, which is characterized by low viscosity, good wettability, high temperature stability, weather resistance, and corrosion resistance; it has excellent compatibility with epoxy resin, and can slow down the reaction speed of epoxy groups while reducing the viscosity of the system, thereby extending the construction period of the coating after mixing;

When in use, the component A: component B is evenly mixed in a weight ratio of 5 to 7 to obtain a solvent-free graphene metal anti-corrosion coating.

The carbon-chloride solution containing more than 99% of the dispersant effective component is preferably BYK-W966, which has excellent ability to reduce the viscosity of the coating and improve the flow characteristics of the coating, thereby obtaining a higher pigment load.

The rheological additive is a high-performance micronized polyamide rheological additive, preferably Arkema polyamide wax powder Crayvallac SLT. Its characteristics are that it can be transformed from a powder state into a fibrous interactive network structure under ordinary high-speed dispersion, so that the coating can obtain good anti-settling performance under low shear conditions; and during construction, that is, under high shear conditions, it can reduce the viscosity of the system and make it easier to construct. After construction, the system returns to low shear conditions and restores the network structure, thereby obtaining excellent anti-sagging performance.

The defoamer is a silicone polymer defoamer, preferably EFKA-2722, which has extremely strong defoaming and defoaming capabilities, especially in the case of thick coating.

The filler is any one of talcum powder, feldspar powder, barium sulfate, zinc oxide, and silicon micropowder, or a combination of several of them.

The metal anti-rust pigment is a combination of zinc powder and aluminum powder, which enables the coating to have excellent cathodic protection ability, thereby improving the anti-corrosion performance.

The graphene slurry is a high-quality thin-layer graphene dispersion with liquid epoxy as the dispersed main body and a solid content of 100%. Preferably, GRF-GEP-2021 high-quality thin-layer graphene epoxy dispersion slurry is selected.

The active diluent is an epoxy compound with unsaturated long chains and benzene rings, and a plant polyphenol glycidyl ether with a bifunctional epoxy active group. Preferably, Naisu PLR-602 is selected, which has high reactivity, good flexibility, stable properties, good water resistance, is derived from plant extraction, is green, environmentally friendly, renewable, and non-toxic, and can be used in combination with epoxy resin to achieve high-filling coatings.

The epoxy curing agent is a solvent-free phenolic amine epoxy resin curing agent, preferably Naisol 730, which has the characteristics of low viscosity and high activity, excellent corrosion resistance and chemical resistance, and can be combined with epoxy resin to achieve long-term corrosion protection.

The promoter is a general Lewis base catalyst, preferably gas chemical K54, whose main component is 2,4,6-tris(dimethylaminomethyl)phenol, and has the characteristics of low viscosity and high wettability.

The present invention further proposes a method for preparing the above-mentioned solvent-free graphene metal anti-corrosion coating, and the preparation method of component A is:

1) Weigh the raw materials according to the proportion, add 5-10 parts of active diluent and 0.5-1.5 parts of dispersant into the batching kettle, stir at a speed of 300-600 rpm for 3-5 minutes until uniformly dispersed; then add 15-35 parts of epoxy resin and 5-15 parts of petroleum resin, stir at a speed of 300-600 rpm for 3-5 minutes until uniformly dispersed;

2) Add 0.5-1.5 parts of rheological additive, 10-20 parts of filler, and 10-20 parts of high temperature resistant pigment in sequence, stir and disperse at a speed of 1000-1200 rpm until the fineness is less than 40 microns;

3) adding 0.1-0.6 parts of defoamer, 10-30 parts of zinc powder, 5-15 parts of aluminum powder, and 1-5 parts of graphene slurry in sequence, stirring and dispersing at a speed of 1000-1200 rpm to a fineness of less than 60 microns to obtain component A;

Preparation method of component B: weigh the raw materials according to the above ratio, 90-95 parts of epoxy curing agent, and 5-10 parts of accelerator, stir at a speed of 600-1000 rpm for 5-10 minutes until the mixture is evenly dispersed to obtain component B.

When in use, the component A: component B is evenly mixed in a weight ratio of 5 to 7 to obtain a solvent-free graphene metal anti-corrosion coating.

Beneficial effects: Compared with traditional solvent-free epoxy coatings, the present invention maintains the following characteristics of solvent-free epoxy coatings:

(1) The entire system uses solvent-free raw materials with a mixed solid content greater than 99.5%, achieving 0 VOC emissions;

(2) The viscosity of the solvent-free coatings currently on the market is very high, and airless spraying is not possible at room temperature. First of all, the raw materials with wetting function are selected with low viscosity, which has good wetting effect on pigments and fillers: the viscosity of the resin is 8000-10000mPa.s, the viscosity of the petroleum resin is 300-400mPa.s, the viscosity of the active diluent is 115-135mPa.s, and the dispersant selected is BYK-W966, whose chemical composition is a salt solution of unsaturated polyamine amide and acidic polyester. This wetting and dispersing aid can improve the dispersion of various commonly used fillers, and can reduce the viscosity of the filling resin and increase the filling amount; when the number of pigments and fillers remains unchanged, it can better reduce the viscosity of the coating. Through the above scheme, the viscosity of the final coating product can reach 80-90KU (25℃), and finally combined with Naisu 730 (viscosity 500-1000mPa.s), the viscosity of the mixed coating is 40-50KU (25℃). Through the synergistic effect of the above solutions, barrier-free construction at room temperature can be achieved, including but not limited to roller coating, brush coating, and airless spraying.

(3) The curing mechanism of epoxy resin is mainly due to the addition reaction between epoxy groups and active hydrogen atoms in the curing agent, generating different types of compounds and forming a 3D cross-linked structure, thereby achieving curing. The functional groups in the active diluent can react with the functional groups in the curing agent. An appropriate amount of active diluent can increase the cross-linking density and accelerate the cross-linking reaction rate, thereby shortening the curing time. Excessive epoxy active diluent will lead to a decrease in cross-linking density and a slow cross-linking reaction rate, thereby reducing the curing efficiency. The addition of petroleum resin amplifies this process, thereby greatly slowing down the reaction speed of the coating after mixing, ensuring that the construction period of the coating after mixing is ≥3 hours (25°C).

(4) The epoxy system contains a large number of polar groups such as hydroxyl and ether groups in its structure, which form extremely strong chemical bonds during the curing process, ensuring excellent adhesion between the coating and the substrate;

(5) Through the application of zinc powder and aluminum powder, the coating has the ability of cathodic protection, and the metal substrate is protected by sacrificial anode to achieve higher corrosion resistance. Secondly, the graphene in the GRF-GEP-2021 graphene dispersion used by Grefeng is a high-quality lamellar structure, which can be stably and evenly dispersed in the system to form a good conductive path, thereby activating the zinc powder and improving the utilization rate of the zinc powder. Even if the amount of zinc powder added is very small, it can achieve efficient corrosion protection.

(6) The graphene in the GRF-GEP-2021 graphene dispersion used in the present invention is a high-quality lamellar structure with a huge specific surface area, thus having excellent coverage, and can fill the pores in the coating from a microscopic level, thereby improving the density and shielding protection of the coating, thereby preventing the penetration of water, oxygen, and salt, thereby improving the overall corrosion resistance of the coating.

(7) The present invention adopts an epoxy system, which can form a smooth coating similar to porcelain glaze after cross-linking and curing. Due to the high cross-linking density and the benzene ring structure in the molecular chain, the coating is hard and flexible, has excellent wear resistance, good scratch resistance, and excellent impact resistance.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and/or other advantages of the present invention will become more clear.

FIG1 is a diagram showing the appearance of the coating prepared in Example 8 after spraying;

FIG2 is a graph showing the impact resistance of the coating prepared in Example 8 after spraying;

FIG3 is a graph showing the 1 mm flexibility test result of the coating prepared in Example 8 after spraying;

FIG4 is a diagram showing the pull-out test results of the coating prepared in Example 8 after spraying;

FIG5 is a graph showing the results of the coating prepared in Example 8 being resistant to neutral salt spray for 1000 hours after spraying.

Detailed ways

In the following examples, whether airless spraying at room temperature can be achieved by adjusting the amount of petroleum resin, active diluent and dispersant added is confirmed, and the influence on the workability of the coating is shown.

The epoxy resin is Miki SM827H, the petroleum resin is Ricon300, the dispersant is BYK-W966; the rheological additive is Arkema polyamide wax powder Crayvallac SLT; the defoamer is EFKA-2722; the filler is silica micropowder; the anti-rust pigment is zinc powder and aluminum powder; the graphene slurry is Grefeng GRF-GEP-2021; the active diluent is Naisuo PLR-602; the epoxy curing agent is Naisuo 730; the accelerator is Gas Chemical K54.

The composition ratios of the solvent-free graphene metal anti-corrosion coatings in Examples 1 to 5 are shown in Table 1.

Table 1

The preparation method of the solvent-free graphene metal anti-corrosion coating in Examples 1 to 5 is as follows:

Preparation method of component A:

1) Weigh the raw materials, active diluent and dispersant according to the proportion, add them into the batching kettle, stir at 300 rpm for 3-5 minutes until they are evenly dispersed; then add epoxy resin and petroleum resin, stir at 500 rpm for 5 minutes until they are evenly dispersed;

2) adding rheological additive, filler and high temperature resistant pigment in sequence, stirring and dispersing at a speed of 1200 rpm until the fineness is less than 40 μm;

3) adding defoamer, zinc powder, aluminum powder and graphene slurry in sequence, stirring and dispersing at a speed of 1000 rpm until the fineness is less than 60 μm to obtain component A;

Preparation method of component B: weigh the raw materials epoxy curing agent and accelerator according to the above ratio, stir at a speed of 600 rpm for 10 minutes until they are evenly dispersed to obtain component B.

The components A and B are mixed evenly in a weight ratio of 6:1 to obtain a solvent-free graphene metal anti-corrosion coating.

According to GB/T 50393-2017 Table A.0.2 solvent-free epoxy coatings and coating performance indicators, the product performance of Examples 1 to 5 is shown in Table 2:

Table 2

Through the test results of Examples 1-5, it can be found that the amount of active diluent and petroleum resin added directly affects the workability of the coating. When the mixed addition amount is greater than 18 parts, it is easier to form a film and apply; when the mixed addition amount is less than 14 parts, the minimum film thickness of the coating reaches 400 microns, and film formation is more difficult; when the mixed addition amount is less than 10 parts, it is completely impossible to spray. With the increase of the amount of active diluent and petroleum resin added, the gain effect is: the construction period is extended, the operable time is longer, and the construction period is significantly improved compared to the 30-minute construction period of conventional solvent-free coatings; the mixed viscosity is getting lower and lower, the workability is excellent, and the film-forming effect is better. Loss effect: the drying time is extended; the sag is reduced.

The composition ratio of the solvent-free graphene metal anti-corrosion coating in Examples 6 to 10 is shown in Table 3. Among them, the epoxy resin is selected from Miki SM827H, the petroleum resin is selected from Ricon300, the dispersant is selected from BYK-W966; the rheological additive is selected from Arkema polyamide wax powder Crayvallac SLT; the defoamer is selected from Efka EFKA-2722; the filler is selected from silicon micropowder; the anti-rust pigment is selected from zinc powder and aluminum powder; the graphene slurry is GRF-GEP-2021; the active diluent is selected from Naisuo PLR-602; the epoxy curing agent is selected from Naisuo 730; the accelerator is selected from Gas Chemical K54.

table 3

The preparation method of the solvent-free graphene metal anti-corrosion coating in Examples 6 to 10 is as follows:

Preparation method of component A:

1) Weigh the raw materials, active diluent and dispersant according to the proportion, add them into the batching kettle, stir at 300 rpm for 3-5 minutes until they are evenly dispersed; then add epoxy resin and petroleum resin, stir at 500 rpm for 5 minutes until they are evenly dispersed;

2) adding rheological additive, filler and high temperature resistant pigment in sequence, stirring and dispersing at a speed of 1200 rpm until the fineness is less than 40 μm;

3) adding defoamer, zinc powder, aluminum powder and graphene slurry in sequence, stirring and dispersing at a speed of 1000 rpm until the fineness is less than 60 μm to obtain component A;

Preparation method of component B: weigh the raw materials epoxy curing agent and accelerator according to the above ratio, stir at a speed of 600 rpm for 10 minutes until they are evenly dispersed to obtain component B.

The components A and B are mixed evenly in a weight ratio of 6:1 to obtain a solvent-free graphene metal anti-corrosion coating.

Figures 1 to 5 show examples of the test of the product prepared in Example 8. Figure 1 is a diagram of the appearance of the coating prepared in Example 8 after spraying, Figure 2 is a diagram of the impact resistance result, Figure 3 is a diagram of the 1mm flexibility test result, Figure 4 is a diagram of the pull-out test result, and Figure 5 is a diagram of the result of neutral salt spray resistance for 1000h.

According to GB/T 50393-2017 Table A.0.2 solvent-free epoxy coatings and coating performance indicators, the product performance of Examples 6 to 10 is shown in Table 4:

Table 4

The present invention provides a preparation idea and method of a solvent-free graphene metal anti-corrosion coating. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims (10)

1. A solvent-free graphene metal anti-corrosion coating, characterized in that it comprises component A and component B, wherein by weight: Component A is 15-35 parts of epoxy resin, 5-15 parts of petroleum resin, 0.5-1.5 parts of dispersant, 0.5-1.5 parts of rheological additive, 0.1-0.6 parts of defoamer, 10-20 parts of filler, 10-30 parts of zinc powder, 5-15 parts of aluminum powder, 5-10 parts of active diluent; 1-5 parts of graphene slurry; Component B is 90-95 parts of epoxy curing agent and 5-10 parts of accelerator; Wherein, the epoxy resin is E51 bisphenol A epoxy resin with 100% solid content and a viscosity of 8000-10000 mPa.s; The petroleum resin contains 99.9% polybutadiene as an effective ingredient; When in use, the component A: component B is evenly mixed in a weight ratio of 5-7:1 to obtain a solvent-free graphene metal anti-corrosion coating. 2. The solvent-free graphene metal anti-corrosion coating according to claim 1 is characterized in that the dispersant is a carbon-chloride compound solution with an effective ingredient greater than 99%; and the rheological additive is a low-temperature activated polyamide wax powder. 3. The solvent-free graphene metal anti-corrosion coating according to claim 1, characterized in that the rheological additive is a polyamide rheological additive. 4. The solvent-free graphene metal anti-corrosion coating according to claim 1, characterized in that the defoamer is an organosilicon polymer defoamer. 5. The solvent-free graphene metal anti-corrosion coating according to claim 1, characterized in that the filler is any one or a combination of talcum powder, feldspar powder, barium sulfate, zinc oxide, and silicon micropowder. 6. The solvent-free graphene metal anti-corrosion coating according to claim 1, characterized in that the graphene slurry is a thin-layer graphene dispersion with liquid epoxy as the dispersed main body and a solid content of 100%. 7. The solvent-free graphene metal anti-corrosion coating according to claim 1, characterized in that the active diluent is Naisol PLR-602. 8. The solvent-free graphene metal anti-corrosion coating according to claim 1, wherein the epoxy curing agent is a solvent-free phenolic amine epoxy resin curing agent. 9. The solvent-free graphene metal anti-corrosion coating according to claim 1, characterized in that the promoter is a general-purpose Lewis base catalyst. 10. The solvent-free graphene metal anticorrosion coating according to any one of claims 1 to 9, characterized in that the preparation method of component A is: 1) Weigh the raw materials according to the proportion, add 5-10 parts of active diluent and 0.5-1.5 parts of dispersant into the batching kettle, stir at 300-600 rpm for 3-5 minutes until uniformly dispersed; then add 15-35 parts of epoxy resin and 5-15 parts of petroleum resin, stir at 300-600 rpm for 3-5 minutes until uniformly dispersed; 2) Add 0.5-1.5 parts of rheological additive and 10-20 parts of filler in sequence, stir and disperse at a speed of 1000-1200 rpm until the fineness is less than 40 microns; 3) Add 0.1-0.6 parts of defoamer, 10-30 parts of zinc powder, 5-15 parts of aluminum powder, and 1-5 parts of graphene slurry in sequence. Stirring and dispersing at a speed of 1000-1200 rpm until the fineness is less than 60 microns to obtain component A; Preparation method of component B: weigh the raw materials according to the ratio, 90-95 parts of epoxy curing agent, and 5-10 parts of accelerator, stir at a speed of 600-1000 rpm for 5-10 minutes until component B is evenly dispersed.