A kind of corrosion resistant coating and preparation method thereof

Abstract

The invention relates to the technical field of coatings, and in particular to a corrosion-resistant coating and a preparation method thereof. The coating is composed of the following raw materials by weight: 60 to 70 parts of aqueous acrylic emulsion, 2 to 4 parts of wetting agent, 2 to 4 parts of defoaming agent, 2 to 5 parts of dispersant, 20 to 30 parts of water, and 1 to 8 parts of graphene oxide / strontium titanate nanoparticle composite material. The invention uses aqueous acrylic emulsion as a basis, reduces the use of organic solvents, and reduces pollution to the environment. By adding the graphene oxide / strontium titanate nanoparticle composite material, the corrosion resistance of the coating is improved. The addition of the composite material can enhance the barrier effect of the coating and prevent the penetration of corrosive media. The graphene oxide / strontium titanate nanoparticle composite material prepared by a specific synthesis method has excellent physical properties, such as high specific surface area and good dispersibility, which are helpful to improve the corrosion resistance and mechanical properties of the coating.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a corrosion-resistant coating and a preparation method thereof. Background Art

[0002] Water-based paint is an environmentally friendly paint that uses water as a solvent or dispersion medium. Compared with traditional solvent-based paints, it has significant environmental advantages. The composition of water-based paints usually includes water-based resins, pigments, fillers, additives, and water. This kind of paint has low VOC (volatile organic compound) emissions during the construction process, which helps reduce air pollution and harm to human health.

[0003] Water-based paint has a wide range of applications. It can be used not only for interior and exterior wall coatings in the construction industry, but also in the fields of automobiles, wood products, metal products, and plastic products. In the construction industry, water-based paint is particularly important for improving indoor air quality due to its low VOC emission characteristics, so it is widely used in indoor wall, ceiling, floor and furniture decoration.

[0004] In addition, the application of water-based paints in wood products, metal products and other fields is also expanding. For example, in the furniture manufacturing industry, water-based paints can provide rich color choices, good decorative effects and high-gloss surfaces, while meeting consumers' demands for beautiful and environmentally friendly furniture.

[0005] Although water-based paint has obvious advantages in environmental performance, it still faces some challenges in physical properties, such as difficult construction, poor water resistance, easy peeling, poor fullness, and poor hardness. Therefore, the future development of water-based paint requires continuous breakthroughs in technological innovation to meet higher performance requirements. Summary of the invention

[0006] The present invention aims to provide a corrosion-resistant coating and a preparation method thereof, which are used to solve the problem of insufficient strength of strontium titanate nanoparticles used alone in water-based coatings in the prior art.

[0007] The present invention is achieved through the following technical solutions:

[0008] A corrosion-resistant coating is composed of the following raw materials in parts by weight: 60-70 parts of water-based acrylic emulsion, 2-4 parts of wetting agent, 2-4 parts of defoaming agent, 2-5 parts of dispersant, 20-30 parts of water, and 1-8 parts of graphene oxide / strontium titanate nanoparticle composite material.

[0009] Furthermore, the wetting agent is selected from alkyl polyoxyethylene ether, the defoaming agent is selected from polydimethylsiloxane, and the dispersant is selected from one of carboxymethyl cellulose and hydroxyethyl cellulose.

[0010] Furthermore, the invention is composed of the following raw materials by weight: 65 parts of aqueous acrylic emulsion, 3 parts of alkyl polyoxyethylene ether as a wetting agent, 3 parts of polydimethylsiloxane as a defoaming agent, 3 parts of carboxymethyl cellulose as a dispersant, 25 parts of water, and 1 to 8 parts of graphene oxide / strontium titanate nanoparticle composite material.

[0011] Further, the content of the graphene oxide / strontium titanate nanoparticle composite material is 3 to 7 parts. Further, the content of the graphene oxide / strontium titanate nanoparticle composite material is 4 parts, and the paint film adhesion of the corrosion-resistant coating is not less than 5.14 MPa.

[0012] Furthermore, the synthesis method of the graphene oxide / strontium titanate nanoparticle composite material is: taking 4 mg of strontium titanate nanoparticles and adding them to 15 mL of 0.001M CATB aqueous solution, then adding 1 mL of 15 mg / mL graphene oxide aqueous solution, ultrasonicating for 60 minutes, centrifuging to obtain a precipitate, and vacuum drying the precipitate at 80°C to obtain the graphene oxide / strontium titanate nanoparticle composite material.

[0013] Furthermore, the synthesis method of the strontium titanate nanoparticles is: take 2g Sr(NO3)2·6H2O and 4.72g tetraisopropyl titanate and disperse them in 100mL DMF, then heat to 85°C and react for 1h; then rotary evaporate most of the DMF, then dry at 110°C for 24h, and then calcine at 600°C to obtain strontium titanate nanoparticles.

[0014] The present invention also provides a method for preparing a corrosion-resistant coating, comprising the following steps: first adding an aqueous acrylic emulsion at room temperature, and then adding a wetting agent, a defoaming agent, a dispersant and water in sequence at a stirring speed of 1000 rpm, wherein each material is added with an interval of 2 minutes before adding the next material, and after all materials are added, stirring at 1000 rpm for 10 minutes; then increasing the stirring speed to 1500 rpm, and then adding the graphene oxide / strontium titanate nanoparticle composite material.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0016] Using water-based acrylic emulsion as the basis reduces the use of organic solvents and reduces pollution to the environment. The corrosion resistance of the coating is improved by adding graphene oxide / strontium titanate nanoparticle composites. The addition of this composite material can enhance the barrier effect of the coating and prevent the penetration of corrosive media. The graphene oxide / strontium titanate nanoparticle composite prepared by a specific synthesis method has excellent physical properties, such as high specific surface area and good dispersibility, which help to improve the corrosion resistance and mechanical properties of the coating. Compared with traditional corrosion-resistant coatings, this coating may have a lower production cost while providing similar or better performance. The preparation method is simple, easy to operate, and is carried out at room temperature, reducing energy consumption and cost. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. The illustrative embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0018] All chemical reagents in the present invention were purchased from Sigma without further treatment; the product number of graphene oxide is 796034.

[0019] Preparation Example 1

[0020] Synthesis of strontium titanate nanoparticles: Take 2g Sr(NO3)2·6H2O and 4.72g tetraisopropyl titanate and disperse them in 100mL DMF, then heat to 85°C and react for 1h; then rotary evaporate most of the DMF, then dry at 110°C for 24h, and then calcine at 600°C to obtain strontium titanate nanoparticles.

[0021] Preparation Example 2

[0022] Synthesis of graphene oxide / strontium titanate nanoparticle composite material: Take 4 mg of strontium titanate nanoparticles and add them into 15 mL of 0.001 M CATB aqueous solution, then add 1 mL of 15 mg / mL graphene oxide aqueous solution, ultrasonicate for 60 min, centrifuge to obtain a precipitate, and vacuum dry the precipitate at 80°C to obtain a graphene oxide / strontium titanate nanoparticle composite material.

[0023] Example 1

[0024] A corrosion-resistant coating is composed of the following raw materials in parts by weight: 65 parts of water-based acrylic emulsion, 3 parts of alkyl polyoxyethylene ether as a wetting agent, 3 parts of polydimethylsiloxane as a defoaming agent, 3 parts of carboxymethyl cellulose as a dispersant, 25 parts of water, and 1 part of a graphene oxide / strontium titanate nanoparticle composite material.

[0025] A method for preparing a corrosion-resistant coating comprises the following steps: firstly adding a water-based acrylic emulsion at room temperature, and then sequentially adding a wetting agent, a defoaming agent, a dispersant and water at a stirring speed of 1000 rpm, wherein each material is added with an interval of 2 minutes before adding the next material, and after all materials are added, stirring is performed at 1000 rpm for 10 minutes; then the stirring speed is increased to 1500 rpm, and then a graphene oxide / strontium titanate nanoparticle composite material is added.

[0026] Example 2

[0027] A corrosion-resistant coating is composed of the following raw materials in parts by weight: 65 parts of water-based acrylic emulsion, 3 parts of alkyl polyoxyethylene ether as a wetting agent, 3 parts of polydimethylsiloxane as a defoaming agent, 3 parts of carboxymethyl cellulose as a dispersant, 25 parts of water, and 2 parts of a graphene oxide / strontium titanate nanoparticle composite material.

[0028] A method for preparing a corrosion-resistant coating is the same as that in Example 1.

[0029] Example 3

[0030] A corrosion-resistant coating is composed of the following raw materials in parts by weight: 65 parts of water-based acrylic emulsion, 3 parts of alkyl polyoxyethylene ether as a wetting agent, 3 parts of polydimethylsiloxane as a defoaming agent, 3 parts of carboxymethyl cellulose as a dispersant, 25 parts of water, and 3 parts of a graphene oxide / strontium titanate nanoparticle composite material.

[0031] A method for preparing a corrosion-resistant coating is the same as that in Example 1.

[0032] Example 4

[0033] A corrosion-resistant coating is composed of the following raw materials in parts by weight: 65 parts of water-based acrylic emulsion, 3 parts of alkyl polyoxyethylene ether as a wetting agent, 3 parts of polydimethylsiloxane as a defoaming agent, 3 parts of carboxymethyl cellulose as a dispersant, 25 parts of water, and 4 parts of a graphene oxide / strontium titanate nanoparticle composite material.

[0034] A method for preparing a corrosion-resistant coating is the same as that in Example 1.

[0035] Example 5

[0036] A corrosion-resistant coating is composed of the following raw materials in parts by weight: 65 parts of water-based acrylic emulsion, 3 parts of alkyl polyoxyethylene ether as a wetting agent, 3 parts of polydimethylsiloxane as a defoaming agent, 3 parts of carboxymethyl cellulose as a dispersant, 25 parts of water, and 5 parts of a graphene oxide / strontium titanate nanoparticle composite material.

[0037] A method for preparing a corrosion-resistant coating is the same as that in Example 1.

[0038] Example 6

[0039] A corrosion-resistant coating is composed of the following raw materials in parts by weight: 65 parts of water-based acrylic emulsion, 3 parts of alkyl polyoxyethylene ether as a wetting agent, 3 parts of polydimethylsiloxane as a defoaming agent, 3 parts of carboxymethyl cellulose as a dispersant, 25 parts of water, and 6 parts of a graphene oxide / strontium titanate nanoparticle composite material.

[0040] A method for preparing a corrosion-resistant coating is the same as that in Example 1.

[0041] Example 7

[0042] A corrosion-resistant coating is composed of the following raw materials in parts by weight: 65 parts of water-based acrylic emulsion, 3 parts of alkyl polyoxyethylene ether as a wetting agent, 3 parts of polydimethylsiloxane as a defoaming agent, 3 parts of carboxymethyl cellulose as a dispersant, 25 parts of water, and 7 parts of a graphene oxide / strontium titanate nanoparticle composite material.

[0043] A method for preparing a corrosion-resistant coating is the same as that in Example 1.

[0044] Example 8

[0045] A corrosion-resistant coating is composed of the following raw materials in parts by weight: 65 parts of water-based acrylic emulsion, 3 parts of alkyl polyoxyethylene ether as a wetting agent, 3 parts of polydimethylsiloxane as a defoaming agent, 3 parts of carboxymethyl cellulose as a dispersant, 25 parts of water, and 8 parts of a graphene oxide / strontium titanate nanoparticle composite material.

[0046] A method for preparing a corrosion-resistant coating is the same as that in Example 1.

[0047] Comparative Example 1

[0048] A corrosion-resistant coating is composed of the following raw materials in parts by weight: 65 parts of water-based acrylic emulsion, 3 parts of alkyl polyoxyethylene ether as a wetting agent, 3 parts of polydimethylsiloxane as a defoaming agent, 3 parts of carboxymethyl cellulose as a dispersant, 25 parts of water, and 1 part of strontium titanate nanoparticles.

[0049] The preparation method is similar to that of the embodiment, specifically, at room temperature, first add an aqueous acrylic emulsion, then add a wetting agent, a defoaming agent, a dispersant and water in sequence at a stirring speed of 1000 rpm, wherein each material is added with an interval of 2 minutes before adding the next material, and after all are added, stir at 1000 rpm for 10 minutes; then increase the stirring speed to 1500 rpm, and then add strontium titanate nanoparticles.

[0050] Comparative Example 2

[0051] A corrosion-resistant coating is composed of the following raw materials in parts by weight: 65 parts of water-based acrylic emulsion, 3 parts of alkyl polyoxyethylene ether as a wetting agent, 3 parts of polydimethylsiloxane as a defoaming agent, 3 parts of carboxymethyl cellulose as a dispersant, 25 parts of water, and 8 parts of strontium titanate nanoparticles.

[0052] The preparation method is the same as that of Comparative Example 1.

[0053] Test Example 1

[0054] In the acid resistance test and alkali resistance test, the sample is Q235 steel with a size of 20 cm × 5 cm. After the surface is oiled and polished, the corrosion-resistant coatings in each embodiment and comparative example are sprayed respectively. After spraying, the surface is dried for 20 minutes and baked at 60°C for 1 hour. In the acid resistance test, the immersion medium is 0.05M H2SO 4； In the alkali resistance test, the immersion medium was 0.1 M NaOH.

[0055] Neutral salt spray test, tested in accordance with GB / T 1771-2007.

[0056] The paint film adhesion is tested in accordance with GB / T 5210-2006 "Adhesion test of paints and varnishes by pull-off method".

[0057] Table 1 Test results of examples and comparative examples

[0058]

[0059] It can be seen from the data in Table 1 that in Examples 1 to 8 and Comparative Examples 1 to 2, no blistering, no discoloration, and no shedding occurred after immersion for 72 hours under acidic and alkaline conditions; in the neutral salt spray resistance test, the requirements were met at 240 hours. In the adhesion of the paint film, the adhesion of the paint film with the addition of strontium titanate nanoparticles alone was improved through the composite of strontium titanate nanoparticles and graphene, and the good compatibility of strontium titanate nanoparticles and graphene was also shown, and the paint film still had good anti-corrosion ability.

Claims

1. A corrosion-resistant coating, characterized in that: The composition is composed of the following raw materials by weight: 65 parts of aqueous acrylic emulsion, 3 parts of wetting agent alkyl polyoxyethylene ether, 3 parts of defoaming agent polydimethylsiloxane, 3 parts of dispersant carboxymethyl cellulose, 25 parts of water, and 1 to 8 parts of graphene oxide / strontium titanate nanoparticle composite material; The synthesis method of the graphene oxide / strontium titanate nanoparticle composite material is as follows: 4 mg of strontium titanate nanoparticles are added to 15 mL of 0.001M CATB aqueous solution, and then 1 mL of 15 mg / mL graphene oxide aqueous solution is added, ultrasonicated for 60 min, centrifuged to obtain a precipitate, and the precipitate is vacuum dried at 80 degrees Celsius to obtain a graphene oxide / strontium titanate nanoparticle composite material; The synthesis method of the strontium titanate nanoparticles is as follows: 2 g of Sr(NO3)2·6H2O and 4.72 g of tetraisopropyl titanate are dispersed in 100 mL of DMF, and then heated to 85 degrees Celsius and reacted for 1 hour; then most of the DMF is evaporated by rotary evaporation, and then dried at 110 degrees Celsius for 24 hours, and then calcined at 600 degrees Celsius to obtain strontium titanate nanoparticles.

2. A corrosion-resistant coating according to claim 1, characterized in that: The content of the graphene oxide / strontium titanate nanoparticle composite material is 3 to 7 parts.

3. A corrosion-resistant coating according to claim 2, characterized in that: The content of the graphene oxide / strontium titanate nanoparticle composite material is 4 parts, and the paint film adhesion of the corrosion-resistant coating is not less than 5.14 MPa.

4. The method for preparing the corrosion-resistant coating according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: firstly adding water-based acrylic emulsion at room temperature, and then sequentially adding a wetting agent, a defoaming agent, a dispersant and water at a stirring speed of 1000 rpm, wherein each material is added with an interval of 2 minutes before adding the next material, and after all materials are added, stirring at 1000 rpm for 10 minutes; then increasing the stirring speed to 1500 rpm, and then adding the graphene oxide / strontium titanate nanoparticle composite material.

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