Epoxy anticorrosive paint and preparation method thereof

Abstract

The invention relates to the technical field of paint, and particularly discloses epoxy anticorrosive paint and a preparation method thereof. The epoxy anticorrosive paint comprises a component A and a component B, the component A is prepared from 20 to 30 parts of epoxy resin liquid, 1 to 5 parts of metal chelate, 20 to 30 parts of mica iron oxide and 25 to 30 parts of filler; the component B comprises 32-45 parts of polyamide; the epoxy resin liquid comprises epoxy resin, a chitosan solution and water; the preparation method comprises the following steps: stirring and mixing the epoxy resin liquid, the metal chelate, the mica iron oxide and the filler to obtain a component A; and stirring and mixing the polyamide of the component A and the polyamide of the component B to obtain the epoxy anticorrosive paint. The epoxy anticorrosive paint provided by the invention not only can effectively block the permeation of corrosive media and water vapor, but also can absorb and reflect ultraviolet rays, and has excellent corrosion resistance and weather resistance.

Description

Technical Field

[0001] The present application relates to the technical field of paints, and more specifically, to an epoxy anti-corrosion paint and a preparation method thereof. Background Art

[0002] Epoxy anticorrosive paint is a type of paint with epoxy resin as the main film-forming substance. It has excellent adhesion and chemical corrosion resistance. Its coating is hard, so it is mainly used for corrosion-resistant coating, such as coating the inner and outer walls of large chemical equipment and pipelines. It can also be used for non-metallic surfaces and electrical appliances and pipeline instruments used in humid tropical conditions. Varnish can be used for priming or finishing metal surfaces.

[0003] However, the epoxy groups in the epoxy resin molecular structure are easily broken under ultraviolet light, so the weather resistance of epoxy anti-corrosion paint is relatively poor, and long-term exposure to sunlight may cause powdering, thereby weakening the anti-corrosion effect of epoxy anti-corrosion paint. Summary of the invention

[0004] In order to improve the weather resistance of epoxy anti-corrosion paint, the present application provides an epoxy anti-corrosion paint and a preparation method thereof.

[0005] In the first aspect, the present application provides an epoxy anti-corrosion paint, which adopts the following technical solution: An epoxy anticorrosive paint comprises a component A and a component B; The A component comprises the following components in parts by weight: 20-30 parts of epoxy resin liquid; 1-5 parts of metal chelate; Mica iron oxide 20-30 parts; 25-30 parts of filler; The B component comprises the following components in parts by weight: Polyamide 32-45 parts; The epoxy resin solution comprises epoxy resin, chitosan solution and water.

[0006] Chitosan has strong emulsification ability and good dispersibility, film-forming property, alkali resistance and weather resistance. By adopting the above technical scheme, chitosan solution and epoxy resin are first prepared into epoxy resin liquid, and then mixed with metal chelate, mica iron oxide and filler. The prepared epoxy anticorrosive paint has excellent emulsification and colloidal protection. It can not only form a dense paint film on the surface of the substrate, effectively blocking the penetration of corrosive media and water vapor, but also absorb and reflect ultraviolet rays, greatly improving the corrosion resistance and weather resistance of the paint.

[0007] Preferably, the epoxy resin liquid comprises the following components in parts by weight: Epoxy resin 38-42 parts; 4-5 parts of butanol; Emulsifier PEG600DO 4-5 parts; Emulsifier OP-10 1 to 1.5 parts; 4-5 parts of dispersant; 28-32 parts of chitosan solution; 18-22 parts of water.

[0008] By adopting the above technical scheme, the non-ionic emulsifier PEG600DO and the emulsifier OP-10 have a good emulsifying effect on the epoxy resin and chitosan solution, so that after mixing, a uniform and stable epoxy resin liquid is formed, which has good wetting properties for the substrate and can effectively improve the corrosion resistance, weather resistance and adhesion of the paint.

[0009] Preferably, the method for preparing the epoxy resin liquid comprises the following steps: S1: adding butanol to epoxy resin at 60-70°C, stirring and mixing, then adding emulsifier PEG600DO and emulsifier OP-10, stirring and mixing, to obtain epoxy resin emulsion; The chitosan solution is added into water, stirred and mixed, and then a dispersant is added, stirred and mixed to obtain a chitosan mixed solution; S2: the chitosan mixed solution is added into the epoxy resin emulsion, stirred and mixed to obtain an epoxy resin liquid.

[0010] By adopting the above technical scheme, the chitosan solution is fully dispersed in water and then added to the epoxy resin emulsion. The two have good compatibility and excellent emulsification effect. The obtained epoxy resin liquid has excellent emulsification and colloid protection, can form a dense paint film on the surface of the substrate, and has good corrosion resistance and weather resistance.

[0011] Preferably, the chitosan in the chitosan solution is water-soluble cationic chitosan.

[0012] By adopting the above technical solution, the water-soluble cationic chitosan has good water solubility and good compatibility with raw materials such as epoxy resin, and the prepared paint has good weather resistance. At the same time, the cations formed by the water-soluble cationic chitosan after dissolving in water can be combined with the metal chelating agent to adsorb the metal ions in the paint to form a dense protective film, which effectively reduces the erosion and degradation of the paint caused by metal ions in an acidic environment and improves the weather resistance and corrosion resistance of the paint.

[0013] Preferably, the metal chelating agent is tripotassium ethylenediaminetetraacetate.

[0014] By adopting the above technical solution, tripotassium ethylenediaminetetraacetate, as a powerful chelating agent, can effectively combine with hydrogen ions in acid rain, reduce the corrosion effect of hydrogen ions on the paint, and is beneficial to improving the corrosion resistance of the paint.

[0015] Preferably, the mica iron oxide is modified mica iron oxide, and its preparation method is: after stirring and mixing the aminosilane coupling agent and water, first add the mica iron oxide and stir and mix, then add carboxyl-modified polyvinyl alcohol, stir and mix, and dry to obtain the modified mica iron oxide.

[0016] By adopting the above technical scheme, the aminosilane coupling agent will generate active silanol groups after hydrolysis, which can undergo condensation reaction with the hydroxyl groups on the surface of mica iron oxide, thereby grafting chemically stable silicon oxygen segments and highly active amino groups on the surface of mica iron oxide. On the one hand, when the aminosilane coupling agent is grafted on the surface of mica iron oxide, the silicon oxygen segments have good resistance to environmental factors such as ultraviolet rays and ozone, which can effectively increase the weather resistance of the paint. On the other hand, most of the highly active amino groups on the surface of mica iron oxide will form positively charged ammonium ions in water, which can undergo condensation reaction with the carboxyl groups in carboxyl-modified polyvinyl alcohol, thereby grafting the carboxyl-modified polyvinyl alcohol on the surface of mica iron oxide, increasing the hydrophilicity of mica iron oxide, which is beneficial to improving the compatibility of modified mica iron oxide and epoxy resin liquid, and further improving the corrosion resistance and weather resistance of the paint.

[0017] Preferably, in the modified mica iron oxide, the weight ratio of mica iron oxide, aminosilane coupling agent, carboxyl-modified polyvinyl alcohol and water is 1:(0.010-0.020):(0.020-0.040):(3-5).

[0018] By adopting the above technical scheme, the amount of carboxyl-modified polyvinyl alcohol is greater than the amount of aminosilane coupling agent, so that the modified mica iron oxide has good hydrophilicity, which is beneficial to improving the dispersibility and compatibility of the modified mica iron oxide in the epoxy resin liquid, and further improving the corrosion resistance and weather resistance of the paint.

[0019] Preferably, the degree of polymerization of the carboxyl-modified polyvinyl alcohol is 300-1500, the degree of alcoholysis is 80-90 mol%, and the carboxyl content is 0.5-3 mol%.

[0020] By adopting the above technical scheme, since the carboxyl-modified polyethylene with the above properties has high surface activity and is easy to react with amino groups, the dispersibility and compatibility of the modified mica iron oxide in the epoxy resin liquid can be improved. Therefore, the paint prepared therefrom has better anti-corrosion and weather resistance.

[0021] In a second aspect, the present application provides a method for preparing an epoxy anti-corrosion paint, using the following technical solution: A method for preparing epoxy anticorrosive paint comprises the following steps: The epoxy resin liquid, metal chelate, mica iron oxide and filler are stirred and mixed to obtain component A; component A and polyamide of component B are stirred and mixed to obtain epoxy anticorrosive paint.

[0022] By adopting the above technical scheme, the raw materials are simply stirred and mixed to prepare the epoxy anti-corrosion paint, which has excellent anti-corrosion and weather resistance and is suitable for large-scale production.

[0023] In summary, this application has the following beneficial effects: 1. Since the present application adopts chitosan solution and epoxy resin to prepare a stable epoxy resin liquid, after mixing with metal chelates, mica iron oxide, etc., the epoxy anticorrosive paint can form a dense paint film on the surface of the substrate to resist the erosion of corrosive media and water vapor, absorb and reflect ultraviolet rays, so the epoxy anticorrosive paint has excellent anticorrosion and weather resistance; 2. In the present application, water-soluble cationic chitosan is preferably used to prepare chitosan solution, which can not only prepare a uniform and stable epoxy resin solution, but also its cationic properties can adsorb metal ions in the paint to form a dense protective film, which effectively improves the weather resistance and corrosion resistance of the paint; 3. The present application uses aminosilane coupling agent and carboxyl-modified polyvinyl alcohol to modify the surface of mica iron oxide, grafts silicon oxide segments and polyvinyl alcohol segments on the surface of mica iron oxide, thereby improving the resistance of the modified mica iron oxide to environmental factors such as ultraviolet rays and ozone, as well as its dispersibility and compatibility in epoxy resin liquid, which is conducive to obtaining epoxy anti-corrosion paint with better weather resistance and corrosion resistance. DETAILED DESCRIPTION

[0024] The present application is further described in detail below with reference to the embodiments.

[0025] Preparation example of epoxy resin liquid Preparation Example 1 An epoxy resin liquid, the components and their corresponding weights (kg) are shown in the following table.

[0026] The preparation method of the above epoxy resin liquid comprises the following steps: S1: Add butanol to epoxy resin 0947A-53W / 0947B-100W at 60-70°C (60°C in the preparation example of the present application), stir and mix for 2 minutes, then add emulsifier PEG600DO and emulsifier OP-10, stir and mix for 10 minutes to obtain epoxy resin emulsion; The chitosan solution was added into water, stirred and mixed for 20 minutes, and then the dispersant ty6010 was added, stirred and mixed for 3 minutes to obtain a chitosan mixed solution; In the preparation example of the present application, the chitosan solution is a 5 wt % chitosan quaternary ammonium salt aqueous solution, and the model of the chitosan quaternary ammonium salt is kqw-5279.

[0027] S2: Add the chitosan mixed solution into the epoxy resin emulsion, stir and mix for 20 minutes to obtain epoxy resin liquid.

[0028] Preparation Examples 2-3 An epoxy resin liquid, which is different from Preparation Example 1 in that the components and their corresponding weights (kg) are shown in the following table.

[0029] Preparation Example 4 An epoxy resin solution is different from the preparation example 1 in that the chitosan solution is a 5wt% chitosan formic acid solution, and the deacetylation degree of chitosan is 75% to 80%.

[0030] Preparation example of modified mica iron oxide Preparation Example 5 A modified mica iron oxide, the components and their corresponding weights (kg) are shown in the following table.

[0031] The preparation method of the modified mica iron oxide is as follows: 3-aminopropyltrimethoxysilane and water are stirred and mixed for 30 minutes, then mica iron oxide is added and stirred and mixed at 40°C for 25 minutes, then carboxyl-modified polyvinyl alcohol is added, stirred and mixed at 80°C for 25 minutes, and finally dried at 90°C for 2 hours to obtain modified mica iron oxide.

[0032] In the preparation example of the present application, mica iron oxide has an active ingredient content of 95%, a particle size of 325 mesh, a density of 4.7-4.9, and an oil absorption of 9-12; the degree of polymerization of carboxyl-modified polyvinyl alcohol is 1500, the degree of alcoholysis is 80 mol%, and the carboxyl content is 0.5 mol%.

[0033] Preparation Examples 6-7 A modified mica iron oxide, which is different from Preparation Example 5 in that the components and their corresponding weights (kg) are shown in the following table.

[0034] Preparation Example 8 A modified mica iron oxide is different from Preparation Example 5 in that an equal weight of polyvinyl alcohol 0388 (with a polymerization degree of 300 and a degree of alcoholysis of 88 mol%) is used to replace the carboxyl-modified polyvinyl alcohol.

[0035] Performance Testing The epoxy anticorrosive paints prepared in the examples and comparative examples of the present application were tested for acid resistance, alkali resistance, neutral salt spray resistance, adhesion and weather resistance. The testing methods are as follows: Acid and alkali resistance test: refer to GB / T9274 test; Neutral salt spray resistance: refer to GB / T1771 test; Adhesion: Refer to GB / T5210 test; Weather resistance: Refer to GB / T1865 test. Example

[0036] Example 1 An epoxy anti-corrosion paint, the components and their corresponding weights (kg) are shown in the following table.

[0037] The preparation method of the above-mentioned epoxy anticorrosive paint comprises the following steps: The epoxy resin liquid, tripotassium ethylenediaminetetraacetate, modified mica iron oxide, talcum powder and ethanol are stirred and mixed for 20 minutes to obtain component A; component A and polyamide 650 of component B are stirred and mixed to obtain epoxy anticorrosive paint.

[0038] In the embodiment of the present application, the epoxy resin liquid adopts the epoxy resin liquid prepared in Preparation Example 1; The modified mica iron oxide adopts the modified mica iron oxide prepared in Preparation Example 5.

[0039] Embodiment 2-3 An epoxy anticorrosive paint, which is different from Example 1 in that the components and their corresponding weights (kg) are shown in the following table.

[0040] The epoxy anticorrosive paints prepared in Examples 1 to 3 of the present application were tested for acid resistance, alkali resistance, neutral salt spray resistance and weather resistance. The test results are shown in the following table.

[0041] By analyzing the data in the above table, it can be seen that the epoxy anticorrosion paint prepared in Examples 1 to 3 has an acid resistance of up to 260 to 280 hours; an alkali resistance of up to 270 to 290 hours; a neutral salt spray resistance of up to 2800 to 3000 hours; a weather resistance gloss loss rate as low as 1 to 7.5%, and a color difference ΔE as low as 0.55 to 0.65. This shows that the epoxy anticorrosion paint prepared in Examples 1 to 3 of the present application has excellent acid resistance, alkali resistance and weather resistance.

[0042] Embodiments 4 to 6 An epoxy anti-corrosion paint, which is different from Example 1 in that the epoxy resin liquid is prepared using the epoxy resin liquid prepared in the preparation example in the following table. Example Preparation example of epoxy resin liquid Example 1 Preparation Example 1 Example 4 Preparation Example 2 Example 5 Preparation Example 3 Example 6 Preparation Example 4

[0043] The epoxy anticorrosive paints prepared in Examples 4 to 6 of the present application were subjected to weather resistance testing, and the test results are shown in the following table.

[0044] By analyzing the data in the above table, it can be seen that in Examples 1, 4, and 5, the light loss rate is as low as 1 to 4.2%, and the color difference ΔE is as low as 0.55 to 0.81. Compared with Example 6, Examples 1, 4, and 5 have lower light loss rate and color difference ΔE changes. This shows that in the total raw materials for preparing the epoxy anti-corrosion paint of the present application, the use of an aqueous solution prepared with water-soluble cationic chitosan to prepare the epoxy resin liquid can improve the weather resistance of the epoxy anti-corrosion paint.

[0045] Embodiments 7 to 9 An epoxy anti-corrosion paint, which is different from Example 1 in that the modified mica iron oxide liquid adopts the modified mica iron oxide prepared by the preparation example in the following table. Example Preparation example of modified mica iron oxide Example 1 Preparation Example 5 Example 7 Preparation Example 6 Example 8 Preparation Example 7 Example 9 Preparation Example 8

[0046] Example 10 An epoxy anticorrosive paint, which is different from Example 1 in that an equal weight of micaceous iron oxide is used to replace the modified micaceous iron oxide, wherein the micaceous iron oxide has an effective ingredient content of 95%, a particle size of 325 mesh, a density of 4.7-4.9, and an oil absorption of 9-12.

[0047] The epoxy anticorrosive paints prepared in Examples 7 to 10 of the present application were subjected to weather resistance testing, and the test results are shown in the following table.

[0048] By analyzing the data in the above table, it can be seen that in Examples 1, 7, and 8, the light loss rate is as low as 1 to 6.8%, and the color difference ΔE is as low as 0.55 to 0.92. Compared with Example 9, Examples 1, 7, and 8 have lower light loss rate and color difference ΔE changes. This shows that in the total raw materials for preparing the epoxy anti-corrosion paint of the present application, the modified mica iron oxide prepared by carboxyl-modified polyvinyl alcohol can improve the weather resistance of the epoxy anti-corrosion paint.

[0049] At the same time, compared with Example 1, the gloss loss rate and color difference ΔE of Examples 7 and 8 are slightly increased. The reason may be that the amount of carboxyl-modified polyvinyl alcohol is greater than the amount of aminosilane coupling agent, which makes the modified mica iron oxide have good hydrophilicity, improves the dispersibility and compatibility of the modified mica iron oxide in the epoxy resin liquid, thereby improving the weather resistance of the epoxy anti-corrosion paint.

[0050] Compared with Example 10, the gloss loss rate and color difference ΔE of Examples 1, 7, 8, and 9 are significantly reduced. This shows that in the total raw materials for preparing the epoxy anti-corrosion paint of the present application, the modified mica iron oxide prepared by using aminosilane coupling agent and carboxyl-modified polyvinyl alcohol can improve the weather resistance of the epoxy anti-corrosion paint.

[0051] In the embodiments of the present application, the aminosilane coupling agent is briefly described by taking 3-aminopropyltrimethoxysilane as an example, and the carboxyl-modified polyvinyl alcohol is briefly described by taking carboxyl-modified polyvinyl alcohol having a degree of polymerization of 1500, a degree of alcoholysis of 80 mol %, and a carboxyl content of 0.5 mol %, but this does not affect the application of other types of aminosilane coupling agents and carboxyl-modified polyvinyl alcohol in the present application.

[0052] Comparative Example Comparative Example 1 An epoxy anti-corrosion paint, which is different from Example 1 in that equal weights of epoxy resin 0947A-53W / 0947B-100W are used to replace the epoxy resin liquid.

[0053] The epoxy anti-corrosion paint prepared in Comparative Example 1 of the present application was tested for acid resistance, alkali resistance, neutral salt spray resistance, adhesion and weather resistance. The test results are shown in the following table.

[0054] By analyzing the data in the above table, it can be seen that compared with Comparative Example 1, the acid resistance, alkali resistance and neutral salt spray resistance of Example 1 are all prolonged, the adhesion is increased, and the gloss loss rate and color difference ΔE are reduced. This shows that the epoxy resin liquid prepared by using chitosan solution and epoxy resin in the total raw materials for preparing the epoxy anti-corrosion paint of the present application can improve the acid resistance, alkali resistance, adhesion and weather resistance of the epoxy anti-corrosion paint.

[0055] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. An epoxy anticorrosive paint, characterized in that: It includes component A and component B; The A component comprises the following components in parts by weight: 20-30 parts of epoxy resin liquid; 1-5 parts of metal chelate; Mica iron oxide 20-30 parts; 25-30 parts of filler; The B component comprises the following components in parts by weight: Polyamide 32-45 parts; The epoxy resin solution comprises epoxy resin, chitosan solution and water.

2. The epoxy anticorrosive paint according to claim 1, characterized in that: The epoxy resin liquid comprises the following components in parts by weight: Epoxy resin 38-42 parts; 4-5 parts of butanol; Emulsifier PEG600DO 4-5 parts; Emulsifier OP-10 1 to 1.5 parts; 4-5 parts of dispersant; 28-32 parts of chitosan solution; 18-22 parts of water.

3. The epoxy anticorrosive paint according to claim 2, characterized in that: The preparation method of the epoxy resin liquid comprises the following steps: S1: adding butanol to epoxy resin at 60-70°C, stirring and mixing, then adding emulsifier PEG600DO and emulsifier OP-10, stirring and mixing, to obtain epoxy resin emulsion; Adding the chitosan solution into water, stirring and mixing, and then adding a dispersant, stirring and mixing to obtain a chitosan mixed solution; S2: adding the chitosan mixed solution into the epoxy resin emulsion, stirring and mixing, and obtaining epoxy resin liquid.

4. The epoxy anticorrosive paint according to claim 1, characterized in that: The chitosan in the chitosan solution is water-soluble cationic chitosan.

5. The epoxy anticorrosive paint according to claim 1, characterized in that: The metal chelating agent is tripotassium ethylenediaminetetraacetate.

6. The epoxy anticorrosive paint according to claim 1, characterized in that: The mica iron oxide is modified mica iron oxide, and its preparation method is: after stirring and mixing the aminosilane coupling agent and water, first add the mica iron oxide and stir and mix, then add carboxyl modified polyvinyl alcohol, stir and mix, and dry to obtain the modified mica iron oxide.

7. The epoxy anticorrosive paint according to claim 6, characterized in that: In the modified mica iron oxide, the weight ratio of mica iron oxide, aminosilane coupling agent, carboxyl-modified polyvinyl alcohol and water is 1:(0.010-0.020):(0.020-0.040):(3-5).

8. The epoxy anticorrosive paint according to claim 6, characterized in that: The carboxyl-modified polyvinyl alcohol has a polymerization degree of 300 to 1500, an alcoholysis degree of 80 to 90 mol %, and a carboxyl content of 0.5 to 3 mol %.

9. The method for preparing the epoxy anticorrosive paint according to any one of claims 1 to 8, characterized in that: The following steps are involved: The epoxy resin liquid, metal chelate, mica iron oxide and filler are stirred and mixed to obtain component A; component A and polyamide of component B are stirred and mixed to obtain epoxy anticorrosive paint.

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