CN115960510A

CN115960510A - Graphene-containing heavy-duty anticorrosive coating and preparation method and application thereof

Info

Publication number: CN115960510A
Application number: CN202111184564.1A
Authority: CN
Inventors: 孙赛; 董文芊; 张丝雨; 邓洁
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2021-10-11
Filing date: 2021-10-11
Publication date: 2023-04-14
Anticipated expiration: 2041-10-11
Also published as: CN115960510B

Abstract

The invention discloses a heavy-duty anticorrosive paint containing graphene and a preparation method and application thereof. The heavy-duty anticorrosive coating containing graphene comprises a component A and a component B, wherein the component A comprises graphene and epoxy resin, the component B is a curing component, and the graphene has the following properties: has a D peak and a G peak in a Raman spectrum, I _D /I _G Below 0.10. The graphene-containing heavy-duty anticorrosive paint has the characteristics of good acid/alkali resistance, strong hydrogen sulfide corrosion resistance, strong salt spray/humidity resistance, high adhesive force and the like, and can be applied to steel structures, ships, offshore platforms and offshore wind power devices to serve as the heavy-duty anticorrosive paint.

Description

Graphene-containing heavy-duty anticorrosive coating and preparation method and application thereof

Technical Field

The invention relates to the field of corrosion prevention, and particularly relates to a heavy-duty anticorrosive coating containing graphene as well as a preparation method and application thereof.

Background

The heavy anti-corrosion coating is used as a coating which can provide long-acting protection for a metal substrate in a severe corrosion environment, and is widely applied to engineering equipment and facilities which are in contact with corrosive media such as seawater, high-sulfur-content crude oil, acid/alkali liquid and the like. China, as a capital-constructed large country, has losses of up to trillion yuan each year due to metal corrosion. Therefore, the development and development of heavy duty anticorrosive coatings are very necessary.

Graphene can effectively prevent a corrosive medium from diffusing to a metal substrate by virtue of good shielding performance, is an upgraded substitute of the traditional zinc-containing heavy-duty anticorrosive coating, and is increasingly put into research and development of graphene coatings by coating researchers in various countries under the large background of zinc resource shortage. CN103897556B discloses a zinc-containing graphene anticorrosive coating, which is prepared by adding a small amount of graphene (less than 2%) and a small amount of zinc powder (less than 30%), and using the synergistic effect of the graphene and the zinc powder to improve the comprehensive performance of the coating, but the adhesion, the salt spray resistance and the ultraviolet light aging resistance of the product still need to be improved, and the product contains zinc, and is not suitable for chemical corrosion environment.

Therefore, the development of the anti-corrosive paint which is resistant to acid/alkali corrosion, resistant to hydrogen sulfide corrosion, strong in salt spray/damp heat resistance, high in adhesive force (more than or equal to 10 MPa) and free of zinc belongs to the technical problem in the field.

Disclosure of Invention

The invention aims to solve the problems that a heavy-duty anticorrosive coating in the prior art is poor in acid/alkali resistance, poor in hydrogen sulfide corrosion resistance, poor in salt spray/humidity resistance, low in adhesive force, large in zinc addition amount and the like, and provides a heavy-duty anticorrosive coating containing graphene and a preparation method and application thereof. The heavy-duty anticorrosive paint containing graphene has the characteristics of good acid/alkali resistance, strong hydrogen sulfide corrosion resistance, strong salt spray/humidity resistance, high adhesion and the like.

In a first aspect, the present invention provides a graphite-containing articleThe graphene-containing heavy-duty anticorrosive coating comprises a component A and a component B, wherein the component A comprises graphene and epoxy resin, the component B is a curing component, and the graphene has the following properties: has a D peak and a G peak in a Raman spectrum, I _D /I _G Below 0.10.

In the technical scheme, the carbon content is more than or equal to 99.50 percent, preferably 99.80 to 99.95 percent, and the oxygen content is less than 300ppm by taking the mass of the graphene as a reference.

In the technical scheme, the particle size of the graphene is 15-35 μm.

In the above technical solution, the graphene is in a three-dimensional cage structure and is a stack of graphene sheets.

In the above technical scheme, the graphene is a stack of petal-shaped graphene sheets.

In the above technical solution, the median particle diameter of the graphene sheet is 5 to 15 μm, preferably 8 to 15 μm.

In the technical scheme, the graphene sheet has 1-10 layers and the thickness of 0.5-3.0nm.

In the above technical scheme, in the raman spectrum of the graphene, I _D /I _G May be 0.01 to 0.10, and further may be 0.03 to 0.10, such as, but not limited to, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, and the like.

In the above technical solution, the conductivity of the graphene is 500-5000S/cm, preferably 1500-4000S/cm, and more preferably 2000-3500S/cm, for example, but not limited to 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3400, 3500, 3600, 3700, 3800, 3900, 4000, and the like.

In the technical scheme, the specific surface area of the graphene is 50-300m ² A ratio of/g, preferably from 100 to 250m ² /g。

In the technical scheme, the tap density of the graphene is 0.02-0.04g/cm ³ 。

In the above technical scheme, the graphene is prepared by a method comprising the following steps:

(1) Pre-expanding graphite to obtain pre-expanded graphite;

(2) Mixing the pre-expanded graphite obtained in the step (1), a wetting agent and a solvent, and sequentially carrying out first high-pressure homogenization treatment and second high-pressure homogenization treatment to obtain graphene slurry; wherein the pressure of the second high-pressure homogenizing treatment is 10-20MPa higher than that of the first high-pressure homogenizing treatment;

(3) And (3) drying the graphene slurry obtained in the step (2) to obtain powder graphene.

In the above technical solution, the pre-expanded graphite obtained in step (1) has an expansion factor of 200 to 300 times as compared with the graphite before pre-expansion.

In the technical scheme, the method for pre-expanding the graphite in the step (1) comprises the following steps: heating the graphite powder to 800-950 ℃, and carrying out expansion treatment for 10-60s to obtain the pre-expanded graphite. Wherein the granularity of the graphite powder is 70-100 meshes.

In the above technical scheme, the wetting agent in the step (2) is fatty amine polyoxyethylene ether. The HLB value of the fatty amine polyoxyethylene ether is more than or equal to 12.

In the technical scheme, in the step (2), the feeding mass ratio of the pre-expanded graphite obtained in the step (1) to the wetting agent is 1:0.01-0.1. The solid content of the graphene slurry is 0.5-5.0 wt%. The solvent is one or more of water and ethanol.

In the technical scheme, the pressure of the first high-pressure homogenization treatment in the step (2) is 30-40MPa, and the treatment time is 20-60min. The pressure of the second high-pressure homogenizing treatment is 40-50MPa, and the treatment time is 10-30min.

In the technical scheme, the solvent residue in the powder graphene obtained in the step (3) is less than or equal to 0.1wt%.

In the above technical solution, the drying in step (3) is preferably spray drying or freeze drying. Wherein, the spray drying conditions are as follows: the temperature of the air inlet is 300-350 ℃, the temperature of the air inlet is 200-250 ℃ higher than that of the air outlet, the temperature of the air outlet is 100-130 ℃, and the rotating speed of a centrifugal disc of the sprayer is 20000-30000rpm. The conditions for the freeze-drying were as follows: the temperature of the cold trap is not higher than-65 ℃, preferably-75 to-70 ℃, the temperature of the box body clapboard is not higher than-55 ℃, preferably-65 to-60 ℃, the temperature rising speed is 0.1 ℃/min to 0.5 ℃/min, the time for raising the temperature of the box body clapboard from the initial temperature to 0 ℃ is not less than 24 hours, preferably 26 to 30 hours, the vacuum degree is not higher than 10Pa, preferably 0.5 to 5Pa.

In the technical scheme, the component A comprises, by weight, 0.1-2 parts of graphene, 10-50 parts of epoxy resin, 0.5-3 parts of hydroxy triazine, 0.5-3 parts of glycidyl ether silane, 10-35 parts of a first solvent and 30-65 parts of a filler. The component B comprises 18-65 parts of curing agent, 0.1-2 parts of aminophenol and 35-80 parts of second solvent.

In the above technical solution, preferably, the component a includes, by weight, 0.1 to 1 part of graphene, 10 to 35 parts of epoxy resin, 0.5 to 2 parts of hydroxytriazine, 0.5 to 2 parts of glycidyl ether silane, 10 to 25 parts of first solvent, and 33 to 65 parts of filler.

In the above technical solution, preferably, the component B includes, by weight, 20 to 65 parts of a curing agent, 0.1 to 2 parts of aminophenol, and 33 to 80 parts of a second solvent.

In the technical scheme, in the heavy-duty anticorrosive paint containing graphene, the mass ratio of the component A to the component B is 10:1-4:1.

in the technical scheme, the heavy anti-corrosion coating containing graphene does not contain metal zinc powder.

In the technical scheme, in the graphene-containing heavy anti-corrosive paint, the epoxy value of the epoxy resin is 0.2-0.6, and preferably, two or three epoxy resins with different epoxy are adopted as the epoxy resin.

In the technical scheme, in the heavy duty anticorrosive coating containing graphene, the glycidyl ether silane is selected from at least one of glycidyl ether oxypropyltriethoxysilane, glycidyl ether oxypropyltrimethoxysilane and glycidyl ether oxypropylmethyldimethoxysilane.

In the technical scheme, in the graphene-containing heavy-duty anticorrosive paint, the filler in the component A is selected from one or more of titanium dioxide, barium sulfate, zinc oxide, bentonite, aluminium dihydrogen tripolyphosphate, talcum powder, carbon black, mica powder and calcium carbonate. The first solvent in the component A is selected from one or more of toluene, xylene, N-butyl acetate, propylene glycol methyl ether acetate, butanone, methyl isobutyl ketone, methanol, ethanol, ethylene glycol, isopropanol, propylene glycol methyl ether, diethylene glycol ethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol butyl ether acetate, ethyl acetate and N-methylpyrrolidone, preferably at least 2 or more solvents are adopted for compounding, and more preferably at least 3 or more solvents are adopted for compounding.

In the technical scheme, in the graphene-containing heavy-duty anticorrosive paint, the component a may further include an auxiliary agent, and the auxiliary agent is one or more selected from a leveling agent, a defoaming agent, a dispersing agent, a dehydrating agent and the like. The component A contains 0.5 to 5 parts of auxiliary agent by weight. The assistant can be selected from leveling agents, antifoaming agents, dispersing agents, dehydrating agents and the like which are commonly used in the field.

In the technical scheme, in the graphene-containing heavy-duty anticorrosive coating, the curing agent in the component B is selected from one or more of phenolic aldehyde amine, phenolic amide and polyamide, preferably one or more of cashew nut shell oil phenolic aldehyde amine, cashew nut shell oil phenolic amide and polyamide, and the curing agent preferably has a hydrogen equivalent of 100-200 and a viscosity of 800cps-3000cps, such as NX-6654, LITE 3060 and NT-1545.

In the technical scheme, in the graphene-containing heavy-duty anticorrosive paint, the aminophenol in the component B is at least one selected from 2-aminophenol, bis [ - (dimethylamino) -methyl ] phenol, and 2, 4, 6-tris (dimethylaminomethyl) phenol.

In the technical scheme, in the graphene-containing heavy-duty anticorrosive coating, the second solvent in the component B is selected from one or more of toluene, xylene, N-butyl acetate, propylene glycol methyl ether acetate, butanone, methyl isobutyl ketone, methanol, ethanol, ethylene glycol, isopropanol, propylene glycol methyl ether, diethylene glycol ethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol butyl ether acetate, ethyl acetate and N-methylpyrrolidone, preferably at least 2 or more solvents are used in a compounding manner, and more preferably at least 3 or more solvents are used in a compounding manner. The second solvent may be the same as or different from the first solvent.

In the technical scheme, the adhesive force of the heavy anti-corrosion coating containing graphene is more than or equal to 14MPa, and preferably 14-15MPa.

In the technical scheme, the heavy anti-corrosion coating containing the graphene does not contain fluorine.

The second aspect of the invention provides a preparation method of the graphene-containing heavy-duty anticorrosive paint, which comprises the following steps:

(1) Mixing graphene, a filler, a first solvent and an optional auxiliary agent, and shearing at a high speed;

(2) Mixing epoxy resin with the mixture obtained in the step (1), and then grinding;

(3) Mixing the mixture obtained in the step (2) with glycidyl ether silane and hydroxy triazine, and shearing at a high speed to obtain a component A;

(4) Mixing a curing agent, aminophenol and a second solvent, and shearing at a high speed to obtain a component B;

(5) And mixing the component A and the component B to prepare the graphene-containing heavy anti-corrosion coating.

In the above technical solution, the high speed shearing conditions in step (1) are as follows: the time is 30-40min, and the rotating speed is 800-1800 rpm. The temperature is controlled to be 30-50 ℃ in the high-speed shearing process in the step (1).

In the technical scheme, the grinding in the step (2) can adopt a sand mill, and the grinding is carried out until the fineness is less than or equal to 25 mu m. Preferably, the grinding media of the sand mill are zirconium beads of 1.5mm to 3 mm.

In the above technical solution, the high speed shearing conditions in the step (3) are as follows: the rotating speed is 800rpm-1300rpm. Dispersing for 20-30 min.

In the above technical solution, the high speed shearing conditions in step (4) are as follows: the time is 10min-20min, and the rotating speed is 800rpm-1200rpm.

The third aspect of the invention provides an application of the graphene-containing heavy anti-corrosive paint in steel structures, ships, offshore platforms and offshore wind power plants.

Further, the film thickness of the heavy anti-corrosion coating containing graphene is preferably 80-120 μm.

Compared with the prior art, the invention has the beneficial effects that:

1. the heavy-duty anticorrosive coating containing the graphene adopts the specific graphene, and has the advantages of less addition amount, strong salt spray resistance and the like compared with the conventional graphene.

2. The heavy-duty anticorrosive coating formula containing graphene is formed by utilizing the mutual matching of a plurality of components in the component A and the component B, has the characteristics of strong adhesive force, strong acid/alkali corrosion resistance, strong hydrogen sulfide corrosion resistance, no zinc, tin, aluminum and other metal substances, strong neutral salt spray resistance, good ultraviolet light aging resistance, small neutral film thickness (80-120 mu m), good brushing performance (no bubbling and peeling), simple construction process (spraying and brushing), can meet the construction requirements of various metal base materials, and can provide comprehensive anticorrosive protection for the metal base materials.

3. The graphene-containing heavy duty anticorrosive coating provided by the present invention has an adhesion of 14MPa or more, a hydrogen sulfide resistance (5% NaCl +5% CH% ₃ COOH+H ₂ S saturated solution) corrosion capacity of 900-1000 h, acid resistance (5% ₂ SO ₄ ) The corrosion capacity and alkali resistance (5 percent NaOH) can reach more than 4500h, the ultraviolet aging resistance time can reach 1000h, and the neutral salt spray resistance can reach more than 2300-3900 h.

4. In the heavy-duty anticorrosive coating containing graphene, due to the matching effect of the added glycidyl ether silane and the hydroxy triazine, graphene can be better dispersed in the coating, the shielding effect and the labyrinth effect of the graphene can be fully exerted, in addition, due to the matching effect of the glycidyl ether silane and the hydroxy triazine and other components such as epoxy resin and the like, an anticorrosive coating with good comprehensive performance is formed on the surface of a base material by the coating, the weather resistance of the coating is obviously improved, and the service life of the base material used in high-temperature, high-humidity, high-salt, high-acid/alkali and other strong-corrosivity environments can be greatly prolonged.

Drawings

FIG. 1 is an SEM photograph of powdered graphene G-1 obtained in example 1;

FIG. 2 is a TEM photograph of powdered graphene G-1 obtained in example 1;

FIG. 3 is an HR-TEM photograph of the graphene G-1 powder obtained in example 1;

FIG. 4 is a Raman spectrum of the powdered graphene G-1 obtained in example 1;

FIG. 5 is an XRD pattern of the powdered graphene G-1 obtained in example 1;

FIG. 6 is a Raman spectrum of powdered graphene G-2 obtained in example 2;

FIG. 7 is an SEM photograph of powdered graphene DG-1 obtained in comparative example 1;

FIG. 8 is an HR-TEM image of the powdered graphene DG-1 obtained in comparative example 1;

FIG. 9 is a Raman spectrum of powdered graphene DG-1 obtained in comparative example 1;

FIG. 10 is a schematic diagram of the anticorrosion mechanism of a conventional anticorrosive coating and a graphene-containing heavy anticorrosive coating according to the present invention;

FIG. 11 is a photograph of an epoxy anticorrosive coating of example 3 after neutral salt spray corrosion test (3600 h);

FIG. 12 is a photograph of an epoxy anticorrosive coating of comparative example 9 after a neutral salt spray corrosion test (800 h).

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In the invention, a Scanning Electron Microscope (SEM) is adopted to characterize the morphology of the electrode material, specifically, the SEM is a TECNALG2F20 (200 kv) model of FEI company in America, and the test conditions are as follows: the sample was pressed directly onto the sample stage containing the conductive tape and then observed by insertion into an electron microscope. The observation was performed using 8000 magnifications.

In the present invention, the morphology of the electrode material was characterized by using a JEM-2100 transmission electron microscope (TEM, HR-TEM) available from Japan Electron Co., ltd. And (3) testing conditions are as follows: the sample is placed in a copper support net and then is inserted into an electron microscope for observation. The observations used 17000 and 380000 magnifications.

In the invention, the median particle size of the graphene sheet is obtained by dynamic light scattering characterization, and a laser particle size analyzer with the equipment model of MS-3000 of Malvern Panalytical company is adopted. And (3) testing conditions are as follows: the sample is dispersed by deionized water with the concentration of 0.01mg/ml, and the setting range of the instrument shading degree is 5-20 percent when the sample is tested after 10min of ultrasonic treatment.

In the invention, the prepared ternary cathode material is subjected to XRD analysis by adopting a D/max-2200/PC X-ray diffractometer test of Japan science company. The analytical test conditions were: the 2 theta angle test range is 10 degrees to 70 degrees, and the scanning speed is 6 degrees/min. The voltage of the test tube is 40KV, the current is 40mA, and a Cu-K alpha ray source is used.

In the present invention, the specific surface area was measured by using ASAP2010 specific surface area and pore size distribution measuring apparatus from Micromeritics of USA. And (3) testing conditions: temperature 77K, nitrogen atmosphere.

In the present invention, raman spectra were measured using a 785nm Laser as the excitation light source using an Invia/Reflrx Laser Micro-Raman spectrometer, all samples were placed on a clean glass slide. Wherein, the thickness is 1250-1450cm ^-1 Peak height I of D peak (defect peak) in wavelength range _D At 1500-1700cm ^-1 G peak (sp) in wavelength range ² Hybrid carbon atom vibrational peak) peak height I _G At 2600-2800cm ^-1 The peak height I of the 2D peak (frequency doubling peak of the D peak) in the wavelength range _2D 。

In the invention, the expansion multiple measurement mode is as follows: taking a certain amount of expandable graphite powder, measuring the volume of the graphite powder by using a measuring cylinder, and then placing the graphite powder in a crucible for puffing treatment at a specified temperature. After the treated graphite powder is returned to the room temperature, measuring the volume by using the measuring cylinder again, and calculating the expansion multiple, wherein the formula is as follows:

expansion factor = (volume of expanded graphite after treatment-volume of graphite powder before treatment)/volume of graphite powder before treatment.

In the invention, the measurement mode of the solvent residual rate is as follows: taking 1g of undried graphene powder, placing the undried graphene powder in a vacuum oven, drying for 10 hours at 60 ℃, weighing the mass of the graphene powder again, and calculating the residual amount of the solvent, wherein the formula is as follows:

residual ratio% = (1-mass of graphene powder after drying in grams)/1 × 100%.

In the invention, the tap density test adopts an FT-100E multifunctional tap density tester produced by Richeck instruments, inc. to measure, the test frequency is 200Hz, and the vibration frequency is 5000 times.

In the invention, the conductivity test is carried out by using an ST-2258C multifunctional digital four-probe tester produced by Suzhou crystal lattice Limited, a sample is prepared by a tabletting method, and the preparation steps are as follows: the prepared powder graphene is pressed into a sheet with the thickness of 100 mu m under the pressure of 10MPa, and then a conductivity meter is used for testing.

In the invention, the oxygen content and the carbon content are tested by adopting a FlashSmart-1120265 element analyzer of ThermoFisher company, he gas is used as carrier gas, and the sample injection amount is 1mgx. The mass of the powder graphene is taken as a reference.

The hydrogen sulfide corrosion resistance test of the epoxy anticorrosive paint is carried out according to GB/T4157-2006, the salt spray test is carried out according to GB/T1771-2007, and the paint film adhesion test is carried out according to GB/T1720-1979. Before coating, the paint film is cleaned according to GB/T8923.1-2011.

The present invention will be described in detail below by way of examples.

In the following examples and comparative examples, the room temperature is 25 ℃.

In the following examples and comparative examples, expandable graphite was obtained from aladine reagent. The wetting agent was purchased from Hensmei chemical trade company, inc. under the brand name Surfornic T-10.

Example 1

Preparing graphene:

(1) Taking 100g (75 meshes) of expandable graphite powder, and carrying out expansion treatment for 20s at 900 ℃ to obtain pre-expanded graphite with the expansion multiple of 220 times.

(2) And (2) taking 10g of pre-expanded graphite in the step (1), 0.25g of wetting agent fatty amine polyoxyethylene ether (Surfonic T-10, HLB value of 12.4) and 239.75g of deionized water, adding into a high-pressure homogenizer together, homogenizing under the pressure of 30MPa for 30min, and then, raising the pressure and homogenizing under the pressure of 45MPa for 30min to obtain the graphene slurry.

(3) And (3) drying the slurry by using spray drying equipment, controlling the temperature of an air inlet to be 350 ℃, the temperature of an air outlet to be 100 ℃, controlling the rotating speed of a centrifugal disc of the sprayer to be 20000rpm, and collecting powder from a discharge port to obtain the graphene product G-1.

FIG. 1 is an SEM photograph of a product G-1 obtained in example 1. As can be seen from FIG. 1, G-1 is a three-dimensional cage structure formed by stacking graphene sheets, and the particle size of the powder graphene is 20 μm to 30 μm. FIG. 2 is a TEM image of the product G-1 obtained in example 1. As can be seen from fig. 2, the graphene sheets are stacked, and the result is consistent with the SEM photograph in fig. 1, indicating that G-1 is a three-dimensional cage structure formed by stacking the graphene sheets, and the graphene powder is a stack of petal-shaped graphene sheets. FIG. 3 is an HR-TEM image of G-1 in example 1. As can be seen from the lattice fringes in FIG. 3, the graphene sheets in G-1 are 4-6 layers of few-layer graphene, and have a thickness of about 1.2nm to 1.9 nm. The median particle size of the graphene sheets was 8.5 μm.

FIG. 4 is a Raman spectrum of the graphene G-1 obtained in example 1, and it can be seen from FIG. 4 that the D band (1354 cm) of the graphene is present ^-1 ) Is far smaller than G band (1574 cm) ^-1 ) Peak intensity ratio of the two _D /I _G 0.09, indicating that G-1 had fewer defects. Furthermore, G-1 was found to be 2709cm ^-1 A distinct 2D peak appears, and further validation in conjunction with fig. 3 indicates that G-1 is few-layer graphene. FIG. 5 is an XRD spectrum of G-1, and a significant diffraction peak appears only at 26.63 degrees, and no impurity peak exists, which shows that no oxidation and impurity element doping impurity phase is formed in G-1. As can be seen from the results of the sulfur carbon analyzer, G-1 obtained in example 1 had a carbon content of 99.95% by weight and an oxygen content of 140ppm. The conductivity of G-1 was 3200S/cm and the tap density was 0.028G/cm as measured by a tabletting method ³ Specific surface area of 180m ² The solvent residue ratio was 0.1% per gram.

Example 2

Preparing graphene:

(1) Taking 100g (75 meshes) of expandable graphite powder, and carrying out expansion treatment for 40s at 900 ℃ to obtain pre-expanded graphite with the expansion multiple of 300.

(2) Taking 10g of the pre-expanded graphite, 0.25g of fatty amine polyoxyethylene ether (Surfonic T-10, HLB value of 12.4) and 239.75g of deionized water, adding the materials into a high-pressure homogenizer together, homogenizing at the pressure of 30MPa for 60min, and raising the pressure to 45MPa for 30min to obtain graphene slurry.

(3) And (3) drying the slurry by using spray drying equipment, controlling the temperature of an air inlet to be 350 ℃, the temperature of an air outlet to be 100 ℃, the rotating speed of a centrifugal disc of an atomizer to be 20000rpm, and collecting powder from a discharge hole to obtain the product G-2.

As is clear from the SEM image of G-2, G-2 is a three-dimensional cage structure formed by stacking graphene sheets, and has a particle size of 18 μm to 22 μm. HR-TEM test results show that the graphene sheets in G-2 are few-layer graphene with 4-6 layers, and the thickness is about 1.2nm-1.8 nm. From the dynamic light scattering data, the median particle diameter of the graphene sheet was 10 μm. Raman spectrum test of FIG. 6 shows that D-banding peak position of graphene G-2 is 1346cm ^-1 And the peak position of G is 1565cm ^-1 Peak intensity ratio of the two _D /I _G 0.04, indicating that G-2 had fewer defects. Furthermore, G-2 is at 2702cm ^-1 And a clear 2D peak appears at the position, and further verification shows that G-2 is few-layer graphene. In addition, a significant diffraction peak appears only at 26.63 degrees in the XRD pattern of G-2, and no impurity peak exists, which indicates that no mixed phase formed by oxidation and impurity element doping exists in G-2.

The carbon content of the obtained G-2 was 99.85wt%, and the oxygen content was 140ppm; the electrical conductivity of G-2 was 2000S/cm and the tap density was 0.029G/cm as measured by the tabletting method ³ Specific surface area of 140m ² The solvent residue ratio was 0.1%.

Comparative example 1

Preparing graphene:

(1) 100g (75 meshes) of expandable graphite powder is taken to be subjected to expansion treatment for 20s at 900 ℃, and the pre-expanded graphite with the expansion multiple of 220 times is obtained.

(2) Taking 10g of the pre-expanded graphite, 0.25g of alkylphenol polyoxyethylene ether (Teric N6, HLB value is 10.9) and 239.75g of deionized water, adding the materials into a high-pressure homogenizer together, homogenizing under the pressure of 30MPa for 30min, and increasing the pressure to homogenize under the pressure of 45MPa for 30min to obtain graphene slurry.

(3) And (3) drying the slurry by using spray drying equipment, controlling the temperature of an air inlet to be 350 ℃, the temperature of an air outlet to be 100 ℃, the rotating speed of a centrifugal disc of an atomizer to be 20000rpm, and collecting powder from a discharge hole to obtain the DG-1 product.

From the SEM image (FIG. 7) of DG-1, it is known that the graphene contained in DG-1 is mainly random lamellar stacks in many cases and has no constant particle size. From the HR-TEM test results of FIG. 8, it can be seen that the graphene sheets in DG-1 are 15-20 layers of graphite sheets, and have a thickness of about 4.5nm to 6 nm. Raman spectrum test of FIG. 9 shows that the D-band peak position of the graphene DG-1 is 1351cm ^-1 G-band Peak position 1514cm ^-1 The peak intensity ratio ID/IG was 0.25, indicating that DG-1 had significantly more defects than G-1. In addition, DG-1 is at 2702cm ^-1 The 2D peak is an envelope peak and is not obvious, and further verification shows that DG-1 is a graphite sheet with a large number of layers.

The carbon content of the powder graphene DG-1 is 99.32wt%, and the oxygen content is 240ppm; the electrical conductivity of DG-1 is 800S/cm and the tap density is 0.042g/cm measured by a tabletting method ³ Specific surface area of 60m ² The residual solvent ratio was 0.25%. Comparative example 2

Preparing graphene:

(2) Taking 10g of the pre-expanded graphite, 0.25g of fatty amine polyoxyethylene ether (Surfonic T-10, HLB value of 12.4) and 239.75g of deionized water, adding the materials into a high-pressure homogenizer together, and homogenizing under the pressure of 30MPa for 60min to obtain the aqueous graphene slurry.

(3) And (3) drying the slurry by using spray drying equipment, controlling the temperature of an air inlet to be 350 ℃, the temperature of an air outlet to be 100 ℃, the rotating speed of a centrifugal disc of an atomizer to be 20000rpm, and collecting powder from a discharge hole to obtain the DG-2 product.

As is clear from the SEM image of DG-2, the graphene contained in DG-2 is mainly random lamellar stacks, and has no fixed particle size. As can be seen from the results of HR-TEM tests, the graphene sheets in DG-1 are 10-15 graphite sheets and have a thickness of about 3nm to 4.5 nm. Raman spectrum test shows that the D peak-out position of the graphene DG-2 is 1351cm ^-1 G-band Peak position 1514cm ^-1 Peak intensity ratio of the two _D /I _G A value of 0.2 indicates that DG-2 has significantly more defects than G-1. In addition, DG-2 is at 2702cm ^-1 The peak is shown and is classified as a 2D peak, which only indicates that a small amount of few-layer graphene exists in DG-2.

The obtained DG-2 had a carbon content of 99.95wt% and an oxygen content of 140ppm; the electrical conductivity of DG-2 is 500S/cm and the tap density is 0.08g/cm by using a tabletting method ³ A specific surface area of 12m ² The solvent residue ratio was 0.1%.

Comparative example 3

Preparing graphene:

(2) Taking 10g of the pre-expanded graphite, 0.25g of aliphatic amine polyoxyethylene ether (surfionic T-10, HLB value of 12.4) and 239.75g of deionized water, adding the materials into a high-pressure homogenizer together, and homogenizing under the pressure of 45MPa for 60min to obtain the aqueous graphene slurry.

(3) And (3) drying the slurry by using spray drying equipment, controlling the temperature of an air inlet to be 350 ℃, the temperature of an air outlet to be 100 ℃, the rotating speed of a centrifugal disc of an atomizer to be 20000rpm, and collecting powder from a discharge hole to obtain the DG-3 product.

As is clear from the SEM image of DG-3, DG-3 is composed of random graphene sheets and has no fixed particle size. HR-TEM test results show that the graphene sheets in DG-3 are 4-6 layers of graphene, and the thickness is about 1.2nm-1.9 nm. Raman spectrum test shows that the D-banding peak position of the graphene DG-3 is 1354cm ^-1 G peak position is 1574cm ^-1 Peak intensity ratio of the two I _D /I _G 0.13, indicating DG-The defect of 3 is similar to that of G-1. In addition, the DG-3 is 2709cm ^-1 A sharp peak, attributed to the 2D peak, indicates that DG-3 is composed of graphene few-layer graphene. But the DG-3 is not beneficial to industrial application because the particle size of the graphene is dispersed.

The obtained DG-3 has a carbon content of 99.95wt% and an oxygen content of 140ppm; the electrical conductivity of DG-3 is 1600S/cm and the tap density is 0.018g/cm measured by a tabletting method ³ Specific surface area of 200m ² The solvent residue ratio was 0.1% per gram.

Example 3

(1) Taking 0.5 part of graphene G-1,0.5 part of defoaming agent (brand Deform 6500), 0.5 part of dispersing agent (brand Disponer 9850), 1 part of bentonite, 3 parts of titanium dioxide, 1 part of carbon black, 6 parts of talcum powder, 20 parts of aluminium dihydrogen tripolyphosphate, 8 parts of zinc oxide, 2 parts of mica powder, 10 parts of barium sulfate, 0.5 part of flatting agent, 25.5 parts of solvent (a mixed solvent of toluene, methyl isobutyl ketone, n-butyl acetate, propylene glycol methyl ether and diethylene glycol monobutyl ether, the volume ratio is 1.

(2) And (2) adding 20 parts of bisphenol A type epoxy resin (with the epoxy value of 0.22) into the mixture obtained in the step (1), mechanically stirring, transferring into a sand mill, and grinding for 30min at the rotating speed of 700rpm, wherein the fineness is less than or equal to 25 microns.

(3) And (3) adding 1 part of glycidyl ether silane (KH-560) and 0.5 part of hydroxy triazine into the mixture obtained in the step (2), and shearing and dispersing at the rotating speed of 1200rpm for 20min to obtain a component A.

(4) Taking 45 parts of cashew nut shell oil modified phenolic aldehyde amine curing agent (trade name NX-6654), 1 part of aminophenol (2-aminophenol) and 54 parts of solvent (a mixed solvent of toluene, methyl isobutyl ketone, ethylene glycol, ethyl acetate and diethylene glycol monobutyl ether, and carrying out shearing stirring at 1000rpm for 15min so as to obtain a component B, wherein the volume ratio of the component B is 1.

(5) And (3) uniformly mixing the component A and the component B according to the mass ratio of 4. The paint film in all the embodiments of the invention adopts a two-time spraying process, the two-time spraying interval is 2 hours, and the thickness of the paint film is 90 mu m.

The adhesive force of the heavy anti-corrosion coating containing graphene is 15MPa.

Fig. 11 is a real photograph of the heavy anti-corrosive coating containing graphene obtained in example 3 after a neutral salt spray experiment, and it can be seen from the photograph that after 3450 hours, only a scribe line is marked, and the line is not widened to the two sides due to corrosion, so that the requirements of GB/T1771-2007 are met. The substrate sprayed with the graphene heavy anti-corrosion coating obtained in example 3 is soaked in a hydrogen sulfide test according to GB/T4157-2006, and no bubbling and peeling phenomena occur on the surface of the substrate after a 1000-hour test. After 1000 hours in the ultraviolet aging box, the phenomenon of yellowing and cracking begins to occur. Acid Corrosion resistant 5% by reference to GB/T1763-1979 ₂ SO ₄ And 5% of a test solution of NaOH, and the substrate sprayed with the graphene heavy anti-corrosive coating prepared in example 3 was placed in the above solution, the varnish condition of the surface of the sample panel was observed every 48 hours, and the varnish bubbling phenomenon was observed at 5040h and 4680h for the above two substrates, respectively.

Example 4

(1) Taking 0.5 part of graphene G-2,0.5 part of a defoaming agent (brand Deform 6500), 0.5 part of a dispersing agent (brand Disponer 9850), 1 part of bentonite, 3 parts of titanium dioxide, 1 part of carbon black, 6 parts of talcum powder, 20 parts of aluminium dihydrogen tripolyphosphate, 8 parts of zinc oxide, 2 parts of mica powder, 10 parts of barium sulfate, 0.5 part of a leveling agent, 25.5 parts of a solvent (a mixed solvent of toluene, methyl isobutyl ketone, n-butyl acetate, propylene glycol methyl ether and diethylene glycol monobutyl ether, wherein the volume ratio is 1.

(2) And (2) adding 20 parts of bisphenol A type epoxy resin (10 parts of epoxy resin with the epoxy value of 0.22 and 10 parts of epoxy resin with the epoxy value of 0.55) into the mixture obtained in the step (1), mechanically stirring, and then transferring into a sand mill for grinding for 30min at the rotating speed of 700rpm, wherein the fineness is less than or equal to 25 mu m.

(3) And (3) adding 1 part of glycidyl ether silane (KH-560) and 0.5 part of hydroxy triazine into the mixture obtained in the step (2), and shearing and dispersing at the rotating speed of 1200rpm for 20min to obtain the component A.

(4) Taking 30 parts of cashew nut shell oil modified phenolic aldehyde amine curing agent (No. NT-1545), 1 part of aminophenol (2-aminophenol) and 69 parts of solvent (a mixed solvent of toluene, methyl isobutyl ketone, ethylene glycol, ethyl acetate and diethylene glycol monobutyl ether, and carrying out shearing stirring at 1000rpm for 15min to obtain a component B, wherein the volume ratio of the component B is 1.

(5) Uniformly mixing the component A and the component B according to the mass ratio of 5. The paint film in all the embodiments of the invention adopts a two-time spraying process, the two-time spraying interval is 2 hours, and the thickness of the paint film is 90 mu m.

The adhesive force of the graphene-containing epoxy coating is 15MPa.

After 3360h neutral salt spray test, only the scribed line part has corrosion traces, and the line is not expanded to two sides due to corrosion, so that the requirements of GB/T1771-2007 are met. The substrate sprayed with the graphene heavy anti-corrosion coating obtained in example 4 is soaked in a hydrogen sulfide test according to GB/T4157-2006, and no bubbling and peeling phenomena occur on the surface of the substrate after a 950h test. After 1000 hours in the ultraviolet aging box, the phenomenon of yellowing and cracking begins to occur. Acid Corrosion resistant 5% by reference to GB/T1763-1979 ₂ SO ₄ And 5 percent of NaOH, placing the substrate sprayed with the graphene heavy anti-corrosion coating prepared in example 4 into the solution, observing the surface paint film condition of the sample plate at intervals of 48 hours, and observing that the paint film bubbling phenomenon occurs on the two substrates at 5040 hours and 4920 hours respectively.

Example 5

(1) Taking 1 part of graphene G-1,0.5 part of defoaming agent (brand Deform 6500), 0.5 part of dispersing agent (brand Disponer 9850), 1 part of bentonite, 3 parts of titanium dioxide, 1 part of carbon black, 6 parts of talcum powder, 5 parts of aluminium dihydrogen tripolyphosphate, 8 parts of zinc oxide, 2 parts of mica powder, 10 parts of barium sulfate, 0.5 part of flatting agent, 25 parts of solvent (a mixed solvent of toluene, methyl isobutyl ketone, n-butyl acetate, propylene glycol methyl ether and diethylene glycol monobutyl ether, the volume ratio is 1.

(2) And (2) adding 35 parts of epoxy resin (15 parts of epoxy resin with the epoxy value of 0.22, 15 parts of epoxy resin with the epoxy value of 0.55 and 5 parts of epoxy resin with the epoxy value of 0.4) into the mixture obtained in the step (1), mechanically stirring, and then transferring into a sand mill for grinding for 30min at the rotating speed of 700rpm, wherein the fineness is less than or equal to 25 mu m.

(3) And (3) adding 0.5 part of glycidyl ether silane (KH-560) and 1 part of hydroxy triazine into the mixture obtained in the step (2), and shearing and dispersing for 20min at the rotating speed of 1200rpm to obtain the component A.

(4) Taking 60 parts of cashew nut shell oil modified phenolic aldehyde amine curing agent (trademark LITE 3060), 1 part of aminophenol (2-aminophenol) and 39 parts of solvent (a mixed solvent of toluene, methyl isobutyl ketone, ethylene glycol, ethyl acetate and diethylene glycol monobutyl ether, and the volume ratio is 1.

(5) And (3) uniformly mixing the component A and the component B according to the mass ratio of 8. The paint film in all the embodiments of the invention adopts a two-time spraying process, the spraying interval of the two times is 2 hours, and the thickness of the paint film is 90 mu m.

The adhesive force of the graphene-containing epoxy coating is 15MPa.

After 3960h neutral salt spray test, only the scribed line part has corrosion traces, and the line is not expanded to two sides due to corrosion, so that the requirement of GB/T1771-2007 is met. The substrate sprayed with the graphene heavy anti-corrosion coating obtained in example 5 is soaked in a hydrogen sulfide test according to GB/T4157-2006, and no bubbling and peeling phenomena occur on the surface of the substrate after a 1000-hour test. After 1000 hours in the ultraviolet aging box, the phenomenon of yellowing and cracking begins to occur. Acid Corrosion resistant 5% by reference to GB/T1763-1979 ₂ SO ₄ And 5% NaOH, and the substrate coated with the graphene heavy duty coating prepared in example 5 was placed in the above solution, observed every 48 hoursThe surface paint film condition of the sample was measured, and the two substrates were observed to have the paint film bubbling phenomenon in 5280h and 4860h, respectively.

Example 6

(1) Taking 2 parts of graphene G-1,0.5 part of a defoaming agent (trade name Deform 6500), 0.5 part of a dispersing agent (trade name Disponer 9850), 1 part of bentonite, 3 parts of titanium dioxide, 1 part of carbon black, 6 parts of talcum powder, 5 parts of aluminum dihydrogen tripolyphosphate, 8 parts of zinc oxide, 2 parts of mica powder, 5 parts of barium sulfate, 0.5 part of a flatting agent, 16.5 parts of a solvent (a mixed solvent of toluene, methyl isobutyl ketone, n-butyl acetate, propylene glycol methyl ether and diethylene glycol monobutyl ether, the volume ratio of 1.

(2) And (2) adding 45 parts of bisphenol A type epoxy resin (with the epoxy value of 0.22) into the mixture obtained in the step (1), mechanically stirring, and then transferring into a sand mill, and grinding for 30min at the rotation speed of 700rpm, wherein the fineness is less than or equal to 25 mu m.

(3) And (3) adding 2 parts of glycidyl ether silane (KH-561) and 2 parts of hydroxy triazine into the mixture obtained in the step (2), and shearing and dispersing at the rotating speed of 1200rpm for 20min to obtain a component A.

(4) Taking 19 parts of cashew nut shell oil modified phenolic aldehyde amine curing agent (trademark NX-6654), 1 part of aminophenol (2-aminophenol) and 80 parts of solvent (a mixed solvent of toluene, methyl isobutyl ketone, ethylene glycol, ethyl acetate and diethylene glycol monobutyl ether, the volume ratio of the solvent is 1.

(5) And (3) uniformly mixing the component A and the component B according to the mass ratio of 5. The paint film in all the embodiments of the invention adopts a two-time spraying process, the two-time spraying interval is 2 hours, and the thickness of the paint film is 90 mu m.

The adhesive force of the graphene-containing epoxy coating is 15MPa.

After 3120h of neutral salt spray test, only the lineation part of the graphene-containing epoxy coating has corrosion traces, and the corrosion traces are corrodedThe wires are not expanded to two sides, and the requirement of GB/T1771-2007 is met. The substrate sprayed with the graphene heavy anti-corrosion coating obtained in example 6 is soaked in a hydrogen sulfide test according to GB/T4157-2006, and no bubbling or peeling phenomenon occurs on the surface of the substrate after 900h of test. After 1000 hours, the yellowing and cracking phenomena begin to occur in the ultraviolet aging box. Acid corrosion resistance 5% according to GB/T1763-1979 arrangement ₂ SO ₄ And 5 percent of NaOH, and the substrate sprayed with the graphene heavy anti-corrosive paint prepared in example 6 was placed in the solution, and the surface paint film condition of the sample plate was observed every 48 hours, and the paint film bubbling phenomenon was observed in 4920 hours and 4800 hours for the two substrates, respectively.

Example 7

(1) Taking 0.1 part of graphene G-1,0.5 part of defoaming agent (brand Deform 6500), 0.5 part of dispersing agent (brand Disponer 9850), 1 part of bentonite, 3 parts of titanium dioxide, 1 part of carbon black, 6 parts of talcum powder, 20 parts of aluminium dihydrogen tripolyphosphate, 8 parts of zinc oxide, 2 parts of mica powder, 10 parts of barium sulfate, 0.5 part of flatting agent, 31.4 parts of solvent (a mixed solvent of toluene, methyl isobutyl ketone, n-butyl acetate, propylene glycol methyl ether and diethylene glycol monobutyl ether, the volume ratio is 1.

(2) And (2) adding 10 parts of bisphenol A type epoxy resin (with the epoxy value of 0.22) into the mixture obtained in the step (1), mechanically stirring, and then transferring into a sand mill, and grinding for 30min at the rotating speed of 700rpm, wherein the fineness is less than or equal to 25 mu m.

(3) And (3) adding 3 parts of glycidyl ether silane (Z-6044) and 3 parts of hydroxy triazine into the mixture obtained in the step (2), and shearing and dispersing at the rotating speed of 1200rpm for 20min to obtain the component A.

(4) Taking 65 parts of cashew nut shell oil modified phenolic aldehyde amine curing agent (trademark NX-6654), 1 part of aminophenol (2-aminophenol) and 34 parts of solvent (a mixed solvent of toluene, methyl isobutyl ketone, ethylene glycol, ethyl acetate and diethylene glycol monobutyl ether, the volume ratio of the mixed solvent is 1.

(5) Uniformly mixing the component A and the component B according to the mass ratio of 10 to 1 to obtain the heavy anti-corrosion coating containing graphene, namely spraying the heavy anti-corrosion coating on the pretreated carbon steel substrate by adopting a spraying mode (the spraying pressure is 0.3 MPa). The paint film in all the embodiments of the invention adopts a two-time spraying process, the two-time spraying interval is 2 hours, and the thickness of the paint film is 90 mu m.

The adhesive force of the graphene-containing epoxy coating is 14MPa.

After the epoxy coating containing graphene is subjected to a neutral salt spray test for 1800 hours, only a scribing part has a corrosion trace, and the line is not expanded to two sides due to corrosion, so that the requirement of GB/T1771-2007 is met. The substrate sprayed with the graphene heavy anti-corrosion coating obtained in example 7 is soaked in a hydrogen sulfide test according to GB/T4157-2006, and no bubbling or peeling phenomenon occurs on the surface of the substrate after a 600-hour test. After 700 hours in the ultraviolet aging box, the phenomenon of yellowing and cracking begins to occur. Acid corrosion resistance 5% according to GB/T1763-1979 arrangement ₂ SO ₄ And 5 percent of NaOH, placing the substrate sprayed with the graphene heavy anti-corrosion coating prepared in example 7 into the solution, observing the surface paint film condition of the sample plate at intervals of 48 hours, and observing that the two substrates respectively have paint film bubbling phenomenon at 2040h and 1800 h.

Comparative example 4

Comparative example 4 differs from example 3 only in that graphene DG-1 is used instead of graphene G-1.

The adhesive force of the graphene-containing epoxy coating is 14MPa.

After the epoxy coating containing graphene is subjected to a neutral salt spray test for 1800 hours, only a scribing part has a corrosion trace, and the line is not expanded to two sides due to corrosion, so that the requirement of GB/T1771-2007 is met. According to GB/T4157-2006, the substrate sprayed with the graphene heavy anti-corrosion coating obtained in comparative example 4 is soaked in a hydrogen sulfide test, and no bubbling or peeling phenomenon occurs on the surface of the substrate after a 400-hour test. After 600 hours in the ultraviolet aging box, the phenomenon of yellowing and cracking begins to occur. Acid corrosion resistance 5% according to GB/T1763-1979 arrangement ₂ SO ₄ And 5% of a test solution of NaOH, and the substrate sprayed with the graphene heavy anti-corrosive coating prepared in comparative example 4 was placed in the above solution, the paint film condition of the surface of the substrate was observed every 48 hours, and the above two substrates were observed to be separatedThe film bubbling phenomenon appeared at 1560h and 1440 h.

Comparative example 5

Comparative example 5 differs from example 3 only in that graphene DG-2 is used instead of graphene G-1.

The adhesive force of the graphene-containing epoxy coating is 14MPa.

After 1440h of neutral salt spray test, only the scribed line of the epoxy coating containing graphene is corroded, and the line is not widened to two sides due to corrosion, so that the requirement of GB/T1771-2007 is met. According to GB/T4157-2006, the substrate sprayed with the graphene heavy anti-corrosion coating obtained in comparative example 5 is soaked in a hydrogen sulfide test, and no bubbling or peeling phenomenon occurs on the surface of the substrate after the test for 300 hours. After 450 hours, the yellowing and cracking phenomena begin to occur in the ultraviolet aging box. Acid corrosion resistance 5% according to GB/T1763-1979 arrangement ₂ SO ₄ And 5% of a test solution of NaOH, and the substrate sprayed with the graphene heavy anti-corrosive coating prepared in comparative example 5 was placed in the solution, and the surface paint film condition of the sample was observed every 48 hours, and the two substrates were observed to have paint film bubbling phenomenon at 1080h and 960h, respectively.

Comparative example 6

Comparative example 6 differs from example 3 only in that graphene DG-3 is used instead of graphene G-1.

The adhesive force of the graphene-containing epoxy coating is 14MPa.

After the graphene-containing epoxy coating is subjected to a neutral salt spray test for 2880h, only a scribing part has a corrosion mark, and the line is not expanded to two sides due to corrosion, so that the requirements of GB/T1771-2007 are met. And (3) soaking the substrate sprayed with the graphene heavy anti-corrosion coating obtained in the comparative example 6 in a hydrogen sulfide test according to GB/T4157-2006, wherein no bubbling and peeling phenomena exist on the surface of the substrate after the test for 350 h. And after 750 hours, the yellowing and cracking phenomena begin to occur in the ultraviolet aging box. Acid corrosion resistance 5% according to GB/T1763-1979 arrangement ₂ SO ₄ And 5% of a test solution of NaOH, and the substrate sprayed with the graphene heavy anti-corrosive coating prepared in comparative example 6 was placed in the above solution, the surface varnish condition of the sample was observed every 48 hours, and the above two substrates were observed to show the varnish bubbling phenomenon at 2544 hours and 2400 hours, respectively.

Comparative example 7

Comparative example 7 differs from example 3 only in that no glycidyl ether silane was added.

The adhesive force of the graphene-containing epoxy coating is 5MPa.

After the epoxy coating containing the graphene is subjected to a neutral salt spray test for 720h, only a scribing part has a corrosion trace, and the line is not expanded to two sides due to corrosion, so that the requirement of GB/T1771-2007 is met. According to GB/T4157-2006, a substrate sprayed with the graphene heavy anti-corrosion coating obtained in comparative example 7 is soaked in a hydrogen sulfide test, and no bubbling or peeling phenomenon occurs on the surface of the substrate after a test of 200 hours. After 400 hours in the ultraviolet aging box, the phenomenon of yellowing and cracking begins to occur. Acid corrosion resistance 5% according to GB/T1763-1979 arrangement ₂ SO ₄ And 5% of a test solution of NaOH, and the substrate coated with the graphene heavy anti-corrosive coating prepared in comparative example 7 was placed in the solution, and the surface varnish condition of the sample was observed every 48 hours, and the two substrates were observed to have the varnish bubbling phenomenon at 600 hours and 480 hours, respectively.

Comparative example 8

Comparative example 8 differs from example 3 only in that no hydroxytriazine is added.

The adhesive force of the graphene-containing epoxy coating is 14MPa.

After the epoxy coating containing graphene is subjected to a neutral salt spray test for 2880h, only a scribing part has a corrosion trace, and the line is not expanded to two sides due to corrosion, so that the requirement of GB/T1771-2007 is met. According to GB/T4157-2006, a substrate sprayed with the graphene heavy anti-corrosion coating obtained in the comparative example 8 is soaked in a hydrogen sulfide test, and no bubbling or peeling phenomenon occurs on the surface of the substrate after the test for 350 hours. After 120 hours, the yellowing and cracking phenomena begin to occur in the ultraviolet aging box. Acid corrosion resistance 5% according to GB/T1763-1979 arrangement ₂ SO ₄ And 5% of a test solution of NaOH, and the substrate sprayed with the graphene heavy anti-corrosive coating prepared in comparative example 8 was placed in the above solution, the surface varnish condition of the sample was observed every 48 hours, and the varnish bubbling phenomenon was observed at 2400h and 2160h for each of the above two substrates.

Comparative example 9

Comparative example 9 differs from example 3 only in that commercially available redox graphene (product name SE-1430, a product of science and technology limited, hexi x, usa) is used instead of graphene.

The adhesive force of the graphene-containing epoxy coating is 8.5MPa.

FIG. 12 is a photograph of a product of the graphene-containing heavy duty anticorrosive coating obtained in comparative example 9 after a neutral salt spray experiment, and it can be seen from the photograph that after 800 hours, a large number of bubbling points appear, a corrosion trace is formed at the scribed line, and the line is extended to both sides, which does not meet the requirements of GB/T1771-2007. According to GB/T4157-2006, the substrate sprayed with the graphene heavy anti-corrosion coating obtained in comparative example 9 is soaked in a hydrogen sulfide test, and no bubbling or peeling phenomenon occurs on the surface of the substrate after 100h of test. After 800 hours in the ultraviolet aging box, the phenomenon of yellowing and cracking begins to occur. Acid Corrosion resistant 5% by reference to GB/T1763-1979 ₂ SO ₄ And 5% of a test solution of NaOH, and the substrate coated with the graphene heavy anti-corrosive coating prepared in comparative example 9 was placed in the solution, and the surface varnish condition of the sample was observed every 48 hours, and the two substrates were observed to have the varnish bubbling phenomenon at 480 hours and 240 hours, respectively.

The specific embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. The heavy-duty anticorrosive paint containing graphene is characterized by comprising a component A and a component B, wherein the component A comprises graphene and epoxy resin, the component B is a curing component, and the graphene has the following properties: has a D peak and a G peak in a Raman spectrum, I _D /I _G The content is 0.10 or less, preferably 0.01 to 0.10, more preferably 0.03 to 0.10.

2. The coating according to claim 1, wherein the graphene has an electrical conductivity of 500 to 5000S/cm, preferably 1500 to 4000S/cm, more preferably 2000 to 3500S/cm.

3. Coating according to claim 1, characterized in that the carbon content is > 99.50%, preferably 99.80-99.95%, and the oxygen content is below 300ppm, based on the mass of graphene.

4. The coating according to claim 1, wherein the graphene is a stack of graphene sheets in a three-dimensional cage structure, and the particle size of the graphene is 15 to 35 μm; preferably, the graphene sheets have a median particle size of 5-15 μm, preferably 8-15 μm; further preferably, the graphene sheet has 1-10 layers and a thickness of 0.5-3.0nm.

5. The coating according to claim 1, wherein the graphene has a specific surface area of 50 to 300m ² A/g, preferably of from 100 to 250m ² (iv) g; and/or the tap density of the graphene is 0.02-0.04g/cm ³ 。

6. The coating according to any one of claims 1 to 5, wherein the graphene-containing heavy duty anticorrosive coating comprises, by weight, 0.1 to 2 parts of graphene, 10 to 50 parts of epoxy resin, 0.5 to 3 parts of hydroxytriazine, 0.5 to 3 parts of glycidyl ether silane, 10 to 35 parts of first solvent, and 30 to 65 parts of filler; the component B comprises 18-65 parts of curing agent, 0.1-2 parts of aminophenol and 35-80 parts of second solvent.

7. The coating according to any one of claims 1 to 5, wherein the graphene-containing heavy duty anticorrosive coating comprises, by weight, 0.1 to 1 part of graphene, 10 to 35 parts of epoxy resin, 0.5 to 2 parts of hydroxy triazine, 0.5 to 2 parts of glycidyl ether silane, 10 to 25 parts of first solvent, and 33 to 65 parts of filler; and/or, the component B comprises 20-65 parts of curing agent, 0.1-2 parts of aminophenol and 33-80 parts of second solvent in parts by weight.

8. The coating according to any one of claims 1 to 5, wherein in the graphene-containing heavy anti-corrosive coating, the mass ratio of the component A to the component B is 10:1-4:1.

9. the coating of claim 1, wherein the graphene-containing heavy duty coating is free of metallic zinc powder.

10. The paint according to claim 1, wherein in the graphene-containing heavy-duty anticorrosive paint, the epoxy value of the epoxy resin is 0.2-0.6, and preferably, two or three epoxy resins with different epoxy groups are used as the epoxy resin.

11. The coating according to claim 6, wherein the glycidyl ether silane is at least one of glycidyl ether oxypropyl triethoxysilane, glycidyl ether oxypropyl trimethoxysilane, and glycidyl ether oxypropyl methyldimethoxysilane in the graphene-containing heavy anti-corrosive coating.

12. The paint according to claim 6, wherein in the graphene-containing heavy anti-corrosive paint, the filler in the component A is one or more selected from titanium dioxide, barium sulfate, zinc oxide, bentonite, aluminium dihydrogen tripolyphosphate, talcum powder, carbon black, mica powder and calcium carbonate; and/or the first solvent in the component A is selected from one or more of toluene, xylene, N-butyl acetate, propylene glycol methyl ether acetate, butanone, methyl isobutyl ketone, methanol, ethanol, ethylene glycol, isopropanol, propylene glycol methyl ether, diethylene glycol ethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol butyl ether acetate, ethyl acetate and N-methylpyrrolidone.

13. The coating according to claim 6, wherein the curing agent in the component B is selected from one or more of phenolic aldehyde amine, phenolic aldehyde amide and polyamide, preferably one or more of cashew nut shell oil phenolic aldehyde amine, cashew nut shell oil phenolic aldehyde amide and polyamide, preferably the curing agent has a hydrogen equivalent weight of 100-200 and a viscosity of 800cps-3000cps;

and/or in the graphene-containing heavy-duty anticorrosive coating, the aminophenol in the component B is at least one selected from 2-aminophenol, bis [ - (dimethylamino) -methyl ] phenol, and 2, 4, 6-tris (dimethylaminomethyl) phenol;

and/or the second solvent in the component B is selected from one or more of toluene, xylene, N-butyl acetate, propylene glycol methyl ether acetate, butanone, methyl isobutyl ketone, methanol, ethanol, ethylene glycol, isopropanol, propylene glycol methyl ether, diethylene glycol ethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol butyl ether acetate, ethyl acetate and N-methylpyrrolidone.

14. The coating according to claim 1, wherein the adhesion of the heavy anti-corrosive coating containing graphene is not less than 14MPa, preferably 14-15MPa.

15. The preparation method of the heavy anti-corrosion coating containing graphene as claimed in any one of claims 1 to 14, comprising the following steps:

16. Use of the graphene-containing heavy duty coating of any one of claims 1 to 14 in steel structures, ships, offshore platforms, offshore wind plants.

17. The use according to claim 16, wherein the graphene-containing heavy duty coating has a film thickness of 80 μm to 120 μm.