Inorganic zinc-rich graphene coating and preparation method thereof

Abstract

The application discloses an inorganic zinc-rich graphene coating and a preparation method thereof. The coating is a two-component coating. A component A comprises polyvinyl butyral solution, zinc base, eutectic solvent graphene dispersion slurry, bentonite dispersion, superfine powder, silicon powder, mica iron oxide and dimethylbenzene. A component B comprises tetraethyl orthosilicate solution, polyvinyl butyral resin, butanol and fumed silica. The chlorocholine / alcohol eutectic solvent has solvent properties, catalytic properties and degradation properties. Raw materials are easy to obtain and low in price. The chlorocholine / alcohol eutectic solvent can disperse graphene, so that the graphene is more uniformly dispersed and has better stability. The whole process does not produce pollution and waste of resources. The chlorocholine / alcohol eutectic solvent dispersed graphene slurry added into the inorganic zinc-rich coating can make the coating film have better adhesion and impact resistance. The unique sheet structure of the graphene is combined with the inorganic zinc-rich coating to form a labyrinth physical barrier to isolate corrosion factors, so that the coating film has the characteristics of long-acting protection and salt fog resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of paint technology, and particularly relates to a two-component inorganic graphene zinc-rich paint with excellent adhesion, good impact resistance, good wear resistance, good corrosion medium shielding effect and super salt spray resistance and a preparation method thereof. BACKGROUND

[0002] Graphene is a new type of two-dimensional carbon material composed of carbon atoms and can exist independently and stably with only one layer of carbon atoms. The planar film with a hexagonal shape in a honeycomb lattice is formed by sp 2 Hybrid connection of carbon atoms, which is currently the hardest and thinnest nanometer new material known to mankind. The special architecture of graphene has many excellent physical and chemical properties: large specific surface area (2630 m 2 / g); the electron mobility can reach 2x10 5 cm 2 / (V·s) at room temperature; the light transmittance of graphene with less than 5 layers is >90%; the thermal conductivity can reach 5300 W / (m·K), which is more than 10 times higher than common metals such as gold, silver and copper; the stiffness of single-layer graphene is (300-400) N / m, the Young's modulus of graphene is about 1100 GPa, and the breaking strength is 130 GPa, which is 100 times higher than the best steel.

[0003] In recent years, graphene has rapidly developed in the field of paint due to its large specific surface area, excellent chemical stability and outstanding mechanical properties. Compared with traditional paint, the performance of graphene paint is significantly improved. In the field of anticorrosive paint research, the graphene sheet structure can effectively block the passage of gas atoms, has good thermal stability, chemical stability, strength and friction performance, and can remain stable in high temperature environment or in corrosive gas and liquid, which significantly improves the corrosion resistance of graphene paint and improves the paint usage rate.

[0004] Zinc powder has a sacrificial anode effect, and zinc-rich paint using zinc powder as the main rust and corrosion resistant pigment has a cathodic protection effect on steel substrates, which is one of the most important heavy-duty corrosion protection paint varieties and has been widely used as a primer in the field of steel substrate corrosion protection. However, the overall mechanical damage resistance of the inorganic zinc-rich primer in the prior art is not very strong, and it is still prone to cracking and other problems when subjected to a large mechanical impact, which can cause peeling of the paint surface. Therefore, the use of graphene with a sheet structure and zinc powder in combination can greatly improve the corrosion and corrosion resistance of the paint, reduce the amount of zinc powder used to some extent, save zinc resources, improve the construction performance of inorganic zinc powder paint, and has become a research hotspot at home and abroad.

[0005] At present, the disclosed inorganic graphene zinc-rich coating mainly has graphene powder directly applied in solvent type coating, which actually cannot reflect the characteristics of graphene to make the salt fog resistance time of paint film longer, but will make the salt fog resistance performance worse, and make the corrosion protection period shorter and other technical defects.

[0006] If the above technical bottlenecks can be overcome, the market share of inorganic graphene zinc-rich coating can be greatly expanded. SUMMARY

[0007] Because the specific surface area of graphene is very large, very high interface force can be generated between particles, the interface force makes the particles aggregate into aggregates, is difficult to be wetted and dispersed, and the pole climbing effect of graphene, so that the traditional dispersion methods such as ultrasonic dispersion, high-speed shearing dispersion and the like have limitations and are too long, therefore, the present application disperses graphene by using the solvent property, catalyst, degradation and other characteristics of choline chloride (molecular formula: HOC2H4N+(CH3)3Cl-) / alcohol eutectic solvent, so that the graphene is dispersed more uniformly and has better stability, the graphene slurry dispersed by choline chloride / alcohol eutectic solvent added into inorganic zinc-rich coating can make the paint film not only have better adhesion and impact resistance and wear resistance, but also have the unique sheet structure of graphene to form a labyrinth physical barrier in the coating to isolate the corrosion factors, and provide long-acting protection and salt fog resistance characteristics for the metal.

[0008] The present application aims to provide an inorganic graphene zinc-rich coating with excellent adhesion, good impact resistance, good wear resistance, good corrosion medium shielding effect and super salt fog resistance performance, and a preparation method thereof.

[0009] The object of the present application can be achieved by the following technical solutions.

[0010] An inorganic graphene zinc-rich coating, which is composed of two components A and B, and the mass ratio of component A to component B is (3-6) : 1.

[0011] The component A is composed of the following components:

[0012]

[0013] The component B is composed of the following components:

[0014]

[0015] In the technical scheme of the present application, the polyvinyl butyral solution is prepared by the following steps: high-speed dispersing polyvinyl butyral and isopropyl alcohol to be uniform, to obtain a polyvinyl butyral solution with a concentration of 10-20wt%.

[0016] In the technical scheme of the present application, the polyvinyl butyral is one or both of Qingdao Haocheng 4s polyvinyl butyral and / or 10s polyvinyl butyral.

[0017] In the technical scheme of the present application: the zinc base is zinc powder with a particle size of (300-800) mesh; and the solvent is dimethylbenzene.

[0018] In the technical scheme of the present application: the eutectic solvent graphene dispersion slurry is prepared by the following steps:

[0019] (1) Preparation of eutectic solvent: choline chloride and alcohol are added to a reaction kettle, and stirred at 30-100 DEG C until the reaction solution is transparent, thereby obtaining the eutectic solvent; the alcohol is one or more of isopropyl alcohol, butanol or glycerol;

[0020] (2) Preparation of eutectic solvent graphene dispersion slurry: graphene is added to the eutectic solvent obtained in step (1), and stirred and heated to 50-100 DEG C, and kept for 0.1-2 h until the graphene powder is uniformly dispersed, thereby obtaining the eutectic solvent graphene dispersion slurry.

[0021] In the eutectic solvent graphene dispersion slurry, the mass ratio of choline chloride, alcohol and graphene in step (1) is 0.01-0.5: 0.01-0.5: 0.01-0.1;

[0022] Preferably, the mass ratio of choline chloride, alcohol and graphene in step (1) is 0.01-0.3: 0.01-0.3: 0.01-0.1.

[0023] An inorganic graphene zinc-rich coating, which is composed of two components A and B, and the mass ratio of component A to component B is (3-6): 1.

[0024] A preparation method of an inorganic graphene zinc-rich coating, which comprises the following steps:

[0025] Preparation of A component: polyvinyl butyral liquid, bentonite dispersion, part of solvent are added into a paint mixing kettle, and stirring is started to disperse at high speed until the fineness is less than 90 microns; then, superfine powder, silicon powder and mica iron oxide are added under stirring, and high-speed dispersion is carried out until the fineness is less than 90 microns; zinc base is continuously added under stirring, and then low-speed stirring is carried out until uniform; then, eutectic solvent graphene dispersion slurry is added, and low-speed stirring is carried out until uniform; finally, the remaining solvent is added, and filtration and packaging are carried out to obtain A component.

[0026] Preparation of B component: tetraethyl orthosilicate and butanol are added into a drawing pot, and stirring is started; then, polyvinyl butyral and fumed silica are added under stirring, and high-speed dispersion is carried out until uniform; finally, filtration and packaging are carried out to obtain B component.

[0027] Advantages of the present application:

[0028] The present application adopts choline chloride / alcohol eutectic solvent which has solvent, catalyst and degradation properties, and the raw materials are easy to obtain and low in price. The choline chloride / alcohol eutectic solvent disperses graphene, so that the graphene is more uniformly dispersed and has better stability, and the whole process does not produce pollution and waste of resources. The choline chloride / alcohol eutectic solvent dispersed graphene slurry added into inorganic zinc-rich paint can make the paint film not only have better adhesion and impact resistance, but also have salt spray resistance due to the unique sheet structure of graphene forming a labyrinth physical barrier to isolate corrosion factors and provide long-acting protection for the metal. DETAILED DESCRIPTION

[0029] The present application is further described below in combination with examples, but the protection scope of the present application is not limited thereto:

[0030] The superfine powder is purchased from Hefei Puyan Trade Co., Ltd.

[0031] Table 1: names and amounts of each substance of A component in the implementation columns 1-3 and the comparative implementation columns 1-3

[0032]

[0033] Table 2: names and amounts of each substance of B component in the implementation column and the comparative implementation column

[0034]

[0035]

[0036] The eutectic solvent graphene dispersion slurry of the implementation columns 1-3 and the comparative implementation columns 1-3 is prepared by the following steps:

[0037] (1) Preparation of eutectic solvent: choline chloride and alcohol are added into a reaction kettle, and stirring is carried out at 50 DEG C until the reaction liquid is transparent, so as to obtain the eutectic solvent;

[0038] (2) Preparation of the eutectic solvent graphene dispersion slurry: graphene was added to the eutectic solvent obtained in step (1), and stirred thoroughly and heated to 80℃ for 1h. After the graphene powder was uniformly dispersed, the eutectic solvent graphene dispersion slurry was obtained.

[0039] Preparation method of inorganic graphene zinc-rich coating of Examples 1-3 and Comparative Examples 1-3:

[0040] Preparation of A component: polyvinyl butyral solution, bentonite dispersion, 30% solvent were added to the paint kettle, and high-speed dispersion was carried out under stirring until the fineness was less than 90μm; then, ultra-fine powder, silicon powder and mica iron oxide were added under stirring, and high-speed dispersion was carried out until the fineness was less than 90μm; then, zinc base was continuously added under stirring, and low-speed stirring was carried out until uniform; then, eutectic solvent graphene dispersion slurry was added, and low-speed stirring was carried out until uniform; finally, the remaining solvent was added, and filtration and packaging were carried out to obtain A component.

[0041] Preparation of B component: tetraethyl orthosilicate and butanol were added to a kettle, and polyvinyl butyral and fumed silica were added under stirring, and high-speed dispersion was carried out until uniform; then, filtration and packaging were carried out to obtain B component.

[0042] A component and B component were mixed uniformly, dimethylbenzene was added for dilution until the spraying viscosity, and the properties such as non-volatile content% in Table 3, metal zinc content% in non-volatile matter, drying time, drawing adhesion and neutral salt spray test were tested according to the standard requirements of HG / T5573-2019 “Graphene zinc powder coating”.

[0043] Comparative Example 1

[0044] “0.1 part of eutectic solvent graphene dispersion slurry” in A component was removed, and other conditions were the same as in Example 1.

[0045] Comparative Example 2

[0046] “0.3 parts of eutectic solvent graphene dispersion slurry” in A component was changed to “0.03 parts of graphene powder”, and other conditions were the same as in Example 2.

[0047] Comparative Example 3

[0048] “0.3 parts of eutectic solvent graphene dispersion slurry” in A component was changed to “0.3 parts of solvent graphene dispersion slurry”, and other conditions were the same as in Example 2.

[0049] Preparation of the solvent graphene dispersion slurry: 90 parts of butanol were weighed into a reaction kettle, and 10 parts of graphene powder were added to the container under stirring, and stirred thoroughly for 0.5h until the graphene was uniformly dispersed to obtain the solvent graphene dispersion slurry, which was ready for use;

[0050] Table 3 Main technical indexes of inorganic graphene zinc-rich coating of examples and comparative examples

[0051]

[0052] From the data results of Table 3, it can be seen that:

[0053] (1) In the comparative example 1, no graphene material is added, the impact resistance is only 20 cm, the adhesion is 4.55 MPa, and the salt spray resistance can only reach 1200 h, the single-direction corrosion of the marked area is ≤1.5 mm, and the unmarked area is not blistering, rusting, cracking, or peeling. In the comparative example 2, graphene powder is directly added, and in the comparative example 3, graphene slurry dispersed by a solvent is added. Not only the salt spray resistance of the inorganic zinc-rich coating is not improved, but also the salt spray resistance and adhesion are reduced, and the impact resistance is not improved.

[0054] (2) In the examples 1, 2, and 3, different amounts of eutectic solvent graphene dispersion slurry are added, the impact resistance, drawing adhesion, and salt spray resistance are greatly improved. In particular, in the example 2, 0.3 parts of eutectic solvent graphene dispersion slurry is added, the drawing adhesion can be as high as 10.34 MPa, the salt spray resistance can reach 4008 h, the single-direction corrosion of the marked area is ≤1.5 mm, and the unmarked area is not blistering, rusting, cracking, or peeling.

[0055] From the above, it can be seen that the eutectic solvent of choline chloride / alcohol has the characteristics of solvent, catalyst, and degradation, which can disperse graphene more uniformly and stably. The eutectic solvent of choline chloride / alcohol dispersed graphene slurry added to the inorganic zinc-rich coating can not only make the paint film have better adhesion and impact resistance, but also fully combine the unique sheet structure of graphene with the inorganic zinc-rich coating to form a labyrinth physical barrier to isolate corrosion factors, and provide long-acting protection for the metal in terms of salt spray resistance.

[0056] Finally, it should be noted that the above only describes the preferred embodiments and comparative examples of the present application, and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or make equivalent replacements to some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An inorganic graphene-rich zinc coating, characterized in that: The coating consists of two components, A and B, with a mass ratio of component A to component B of (3-6):

1. Component A consists of the following ingredients: 15-30 parts of polyvinyl butyral solution 44-70 parts zinc base 0.1–0.7 parts of eutectic solvent graphene dispersion. 10-20 parts of bentonite dispersion 2-8 parts of ultrafine powder 1-10 parts of silicon micro powder 1-10 parts of mica iron oxide Solvent 1 to 5 parts Component B consists of the following components: 85-95 parts of tetraethyl orthosilicate 1-3 parts of polyvinyl butyral 3-10 parts of butanol 0.5–1.5 parts of fumed silica; The eutectic solvent graphene dispersion slurry is prepared by the following steps: (1) Preparation of eutectic solvent: Add choline chloride and alcohol to a reaction vessel and stir at 30~100℃ until the reaction solution is transparent to obtain eutectic solvent; the alcohol is one or more of isopropanol, butanol or glycerol. (2) Preparation of graphene dispersion in eutectic solvent: Add graphene to the eutectic solvent obtained in step (1), stir thoroughly and heat to 50~100℃, keep warm for 0.1~2h until the graphene powder is evenly dispersed to obtain the graphene dispersion in eutectic solvent. The mass ratio of choline chloride, alcohols, and graphene is 0.01~0.5 : 0.01~0.5 : 0.01~0.1; The polyvinyl butyral solution is prepared by the following steps: polyvinyl butyral and isopropanol are dispersed at high speed until uniform, thus obtaining a polyvinyl butyral solution with a concentration of 10~20wt%.

2. The inorganic graphene zinc-rich coating according to claim 1, characterized in that... Polyvinyl butyral is one or both of Qingdao Haocheng's 4s polyvinyl butyral and / or 10s polyvinyl butyral.

3. The inorganic graphene zinc-rich coating according to claim 1, characterized in that... The zinc base material is zinc powder with a particle size of 300-800 mesh; the solvent is xylene.

4. The inorganic graphene-rich zinc coating according to claim 1, characterized in that, The mass ratio of choline chloride, alcohols, and graphene is 0.01~0.3:0.01~0.3:0.01~0.

1.

5. The inorganic graphene zinc-rich coating according to claim 1, characterized in that... The bentonite dispersion is prepared by the following steps: bentonite, xylene and isopropanol are mixed in a mass ratio of (0.5~3):(10~15):(0.1~1) and dispersed at high speed to a fineness of less than 90 μm to obtain the bentonite dispersion.

6. The inorganic graphene zinc-rich coating according to claim 5, characterized in that... The bentonite is composed of HFGEL-160 organic bentonite and BS-1C bentonite in a mass ratio of 1~3:1~3.

7. A method for preparing an inorganic graphene-rich zinc coating according to any one of claims 1 to 6, characterized in that: The method includes the following steps: Preparation of Component A: Polyvinyl butyral solution, bentonite dispersion, and part of the solvent were added to a paint mixing tank and stirred at high speed until the fineness was less than 90 μm. Then, under stirring, ultrafine powder, silica powder, and mica iron oxide were added and dispersed at high speed until the fineness was less than 90 μm. Zinc base material was added and stirred at low speed until homogeneous. Then, graphene dispersion, a eutectic solvent, was added and stirred at low speed until homogeneous. Finally, the remaining solvent was added, filtered, and packaged to obtain Component A. Preparation of component B: Tetraethyl orthosilicate and butanol were added to a pan, and polyvinyl butyral and fumed silica were added while stirring. The mixture was then dispersed at high speed until homogeneous, filtered, and packaged to obtain component B.

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