Polyaniline static conductive coating and preparation method thereof

Abstract

The invention relates to the technical field of coatings, in particular to a polyaniline static conductive coating and a preparation method thereof. The polyaniline static conductive coating comprises a component A and a component B, the component A comprises epoxy resin, polyaniline, a gemini surfactant, a dispersing agent, a solvent and an anti-rust pigment; the component B comprises a polyamide curing agent; the weight ratio of the component A to the component B is (3.5-6): 1; wherein the gemini surfactant is anionic disulfonate. According to the polyaniline static conductive coating provided by the invention, the addition amount of polyaniline is low, the surface resistivity is stabilized within the range grade of 109 omega.cm, and because a gemini surfactant specifically added into the coating and polyaniline form chemical adsorption, the cured polyaniline does not migrate, conductive polyaniline is uniformly distributed in the coating, and the static conductive performance of the coating is improved. And the conductivity of the coating is lasting and stable. In addition, a coating layer formed by the paint has good mechanical properties and corrosion resistance.

Description

Technical Field

[0001] The present application relates to the technical field of coatings, and in particular to a polyaniline electrostatic conductive coating and a preparation method thereof. Background Art

[0002] Static conductive coatings are one of the functional coatings in the petrochemical industry. They are used to eliminate the accumulated charge in storage tanks and improve the safety factor. There are two main types of static conductive coatings: The first is additive-type electrostatic conductive coating, which achieves the electrostatic conductive function by adding conductive media. The conductive media mainly include carbon (graphite powder, graphene, carbon nanotubes, etc.), metal fillers, and coated conductive powders (conductive mica powder, conductive titanium dioxide, etc.); The second is intrinsically conductive electrostatic coatings. The film-forming resin of the coating itself is conductive and is usually made of conjugated polymers (such as polyaniline, polypyrrole, polythiophene, etc.). These materials have delocalized π electrons in their molecular structure, which can conduct charges through electron migration.

[0003] Among them, intrinsically conductive static coatings are affected by the poor solubility, poor film-forming properties, and poor mechanical properties of conductive polymers, and usually require compounding with other types of resins. The conductive polymers in this type of coating mainly exist in the form of dispersed nanoparticles.

[0004] Polyaniline (PAI) is the most widely reported and applied conductive polymer in electrostatically conductive coatings. Its excellent dispersibility is key to the coating's electrostatic conductivity. However, due to its poor dispersibility, PAI requires excessive addition, which degrades the mechanical properties of the resulting coating. Current popular approaches typically pre-treat PAI with dispersants or silane coupling agents, but this still poses the problem of PAI agglomeration due to desorption, resulting in poor surface resistivity stability and durability, and poor conductivity. Summary of the Invention

[0005] To address the problems of the prior art mentioned in the background art, the present application provides a polyaniline electrostatic conductive coating. This coating is based on a gemini surfactant-doped polyaniline. This coating prevents polyaniline from agglomerating or migrating after dispersion, resulting in a stable and long-lasting surface resistivity of the coating. The technical solution for this polyaniline electrostatic conductive coating is as follows: The present application provides a polyaniline electrostatic conductive coating, which includes a component A and a component B; in parts by weight, the component A includes 20 to 30 parts of epoxy resin, 5 to 10 parts of polyaniline, 0.1 to 0.5 parts of a gemini surfactant, 0.1 to 0.5 parts of a dispersant, 20 to 30 parts of a solvent, and 35 to 50 parts of an anti-rust pigment; the component B includes a polyamide curing agent; the weight ratio of the component A to the component B is (3.5 to 6):1; wherein the gemini surfactant is an anionic disulfonate.

[0006] In some embodiments, the gemini surfactant is sodium didodecyl diphenyl ether disulfonate, and its mass is 1% to 5% of the mass of polyaniline.

[0007] In some embodiments, the component A is composed of 20 to 30 parts of epoxy resin, 5 to 10 parts of polyaniline, 0.1 to 0.5 parts of gemini surfactant, 0.1 to 0.5 parts of dispersant, 20 to 30 parts of solvent, and 35 to 50 parts of anti-rust pigment, by weight; the component B is composed of a polyamide curing agent.

[0008] In some embodiments, the epoxy resin is bisphenol A epoxy resin E51.

[0009] In some embodiments, the polyaniline is intrinsic polyaniline.

[0010] In some embodiments, the anti-rust pigment is one or more combinations of zinc phosphate and iron titanium powder.

[0011] In some embodiments, the dispersant is one or a combination of BYK-110 and Euka 710S; the solvent is a mixture of butanone and N-methylpyrrolidone, and the mass ratio of butanone to N-methylpyrrolidone is 3:1.

[0012] In some embodiments, the polyamide curing agent has an amine value of 200 to 240 mgKOH / g.

[0013] The present application also provides a method for preparing the polyaniline electrostatic conductive coating as described above, which comprises the following steps: The preparation process of component A is as follows: A mixture of butanone and N-methylpyrrolidone is selected as the solvent, polyaniline and gemini surfactant are added to the N-methylpyrrolidone, stirring is started, heating to 40° C. to 60° C., stirring for a certain time, and then ultrasonically treating for a certain time to obtain a doped polyaniline dispersion; The epoxy resin, doped polyaniline dispersion, butanone and dispersant are uniformly dispersed at high speed; finally, the anti-rust pigment is added and dispersed at high speed until the fineness is ≤80μm, thus obtaining component A; The preparation process of component B is as follows: the polyamide curing agent is packaged.

[0014] In some embodiments, the preparation process of component A is: Add polyaniline and gemini surfactant to N-methylpyrrolidone, start stirring, heat to 40°C to 60°C, stir for 2 hours, and then ultrasonicate for 30 minutes to 60 minutes to obtain a doped polyaniline dispersion; The epoxy resin, doped polyaniline dispersion, butanone and dispersant are uniformly dispersed at high speed; finally, the anti-rust pigment is added and dispersed at high speed until the fineness is ≤80μm, thereby obtaining component A.

[0015] Compared with the existing technology, the polyaniline electrostatic conductive coating provided in this application has the following beneficial effects: The present application provides a polyaniline electrostatic conductive coating, which has a low polyaniline addition amount and a surface resistivity stable at 10 9 The conductive polyaniline is uniformly distributed throughout the coating, ensuring long-lasting and stable conductivity. Furthermore, the coating exhibits excellent mechanical properties and corrosion resistance. DETAILED DESCRIPTION

[0016] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the following will be described clearly and completely in conjunction with the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0017] In order to verify the effect of this application, this application also provides the following examples and comparative example 1: The formulas of the examples and comparative examples of this application are shown in Table 1-2: Table 1 Example formula (unit, mass parts)

[0018] Table 2 Comparative Example Formula (Unit, mass parts)

[0019] The difference between the comparative example and the embodiment is: Comparative Example 1 The only difference between this comparative example and Example 2 is that conductive polyaniline of equal mass is used instead of the polyaniline in Example 2, and silane coupling agent KH550 of equal mass is used instead of the gemini surfactant in Example 2. Other preparation processes and conditions are the same as those in Example 1.

[0020] Comparative Example 2 The only difference between this comparative example and Example 2 is that a monophilic hydrophobic anionic surfactant is used to replace the gemini surfactant in Example 2, and the surfactant used in this comparative example is specifically sodium lauryl sulfate. The other preparation processes and conditions are the same as those in Example 1.

[0021] The specific raw material selections in Table 1-2 are as follows: (1) The epoxy resin used is bisphenol A epoxy resin E51.

[0022] (2) The polyaniline used is intrinsic polyaniline.

[0023] (3) The gemini surfactant used is an anionic disulfonate, specifically sodium didodecyl diphenyl ether disulfonate.

[0024] (4) The dispersant used is a commonly used dispersant for anti-corrosion coatings, specifically Euka 710S.

[0025] (5) The solvent used was a mixture of butanone and N-methylpyrrolidone in a mass ratio of 3:1.

[0026] (6) The anti-rust pigment used is zinc phosphate.

[0027] (7) The amine value of the polyamide curing agent used is 200-240 mgKOH / g.

[0028] In addition, the specific preparation process is as follows: The preparation method of component A is: Polyaniline and gemini surfactant were added to N-methylpyrrolidone, magnetic stirring was started, and the mixture was heated to 50°C. After continuous stirring for 2 hours, ultrasonic treatment was performed for 40 minutes to obtain a doped polyaniline dispersion. Add epoxy resin, polyaniline dispersion, butanone and dispersant into an empty can and disperse at high speed for about 20 minutes; Add anti-rust pigment and disperse at high speed to a fineness of ≤80μm.

[0029] The preparation method of component B is as follows: the polyamide curing agent is packaged.

[0030] Performance Testing In Example 1, component A and component B were mixed in a mass ratio of 100:17, in Example 2, component A and component B were mixed in a mass ratio of 100:21.5, and in Example 3, component A and component B were mixed in a mass ratio of 100:25.8 to obtain coatings.

[0031] In comparative example 1, component A and component B were mixed in a mass ratio of 100:21.5, and in comparative example 2, component A and component B were mixed in a mass ratio of 100:21.5 to obtain coatings.

[0032] The coating was tested for performance, and the test results are shown in Table 3-4: Table 3 Performance data

[0033] Table 4 Performance data

[0034] Analyzing the above data: The polyaniline electrostatic conductive coating provided in the embodiment of the present application has a low polyaniline addition amount and a surface resistivity that is stable at 10 9 The conductive polyaniline is uniformly distributed throughout the coating, maintaining long-lasting conductivity and resisting oil immersion for 30 days. The surface resistivity remains essentially stable, while the resistivity of the control increases. Furthermore, the coating exhibits excellent mechanical properties and corrosion resistance.

[0035] In summary, the present application has the following design concepts, mechanisms of action, and beneficial effects: The present application scheme adopts a specific Gemini surfactant, which can be used as an acid dopant and dispersant for polyaniline at the same time. The Gemini surfactant has two sulfonic acid groups and two hydrophobic chains, and has higher interfacial activity. The two sulfonic acid groups are firmly adsorbed on the surface of the polyaniline particles through ionic bonds and hydrogen bonds to form chemical doping, which is not easy to dedope. Acid doping can improve conductivity; the double hydrophobic chains form a steric hindrance effect to prevent polyaniline from agglomerating, achieving uniform dispersion without agglomeration. At the same time, the alkyl chain and the fatty chain segment of the epoxy resin are temporarily combined through hydrophobic action to achieve uniform suspension of polyaniline. When the curing agent is added to form an epoxy cross-linked network, the polyaniline particles are fixed, and the alkyl chain is wrapped in the cross-linked structure to prevent subsequent migration, and the coating resistivity is stable.

[0036] In summary, the present application provides a polyaniline electrostatic conductive coating with a low polyaniline addition amount and a surface resistivity stable at 10 9 The conductive polyaniline coating has a conductivity range of Ω·cm. Furthermore, the addition of a gemini surfactant to the coating chemically adsorbs onto the polyaniline, preventing polyaniline migration after curing. The conductive polyaniline is evenly distributed throughout the coating, resulting in a long-lasting and stable conductivity. Furthermore, the resulting coating exhibits excellent mechanical properties and corrosion resistance. The polyaniline conductive static coating provided herein is suitable for coating the interior walls of petrochemical storage tanks.

[0037] It should be noted that: In this article, “~” is used to indicate a numerical range, and the range indicated by this expression includes two endpoint values.

[0038] In addition to the actual selections embodied in the above specific embodiments, the above formulation ranges may be adopted in the specific implementation of this application, including but not limited to the above embodiment schemes.

[0039] The specific parameters or some commonly used reagents or raw materials in the above embodiments are specific embodiments or preferred embodiments of the present application, and are not intended to limit the present application. Those skilled in the art may make adaptive adjustments within the scope of the present application.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A polyaniline electrostatic conductive coating, characterized by: Including component A and component B; Calculated by weight, the component A comprises 20 to 30 parts of epoxy resin, 5 to 10 parts of polyaniline, 0.1 to 0.5 parts of gemini surfactant, 0.1 to 0.5 parts of dispersant, 20 to 30 parts of solvent, and 35 to 50 parts of anti-rust pigment; The second component includes a polyamide curing agent; The weight ratio of the component A to the component B is (3.5-6):1; Wherein, the gemini surfactant is an anionic disulfonate.

2. The polyaniline electrostatic conductive coating according to claim 1, characterized in that: The gemini surfactant is sodium didodecyl diphenyl ether disulfonate, and its mass is 1% to 5% of the mass of polyaniline.

3. The polyaniline electrostatic conductive coating according to claim 1, characterized in that: Calculated by weight, the component A consists of 20 to 30 parts of epoxy resin, 5 to 10 parts of polyaniline, 0.1 to 0.5 parts of gemini surfactant, 0.1 to 0.5 parts of dispersant, 20 to 30 parts of solvent, and 35 to 50 parts of anti-rust pigment; The second component consists of a polyamide curing agent.

4. The polyaniline electrostatic conductive coating according to claim 1, characterized in that: The epoxy resin is bisphenol A epoxy resin E51.

5. The polyaniline electrostatic conductive coating according to claim 1, characterized in that: The polyaniline is intrinsic polyaniline.

6. The polyaniline electrostatic conductive coating according to claim 1, characterized in that: The anti-rust pigment is one or more combinations of zinc phosphate and iron titanium powder.

7. The polyaniline electrostatic conductive coating according to claim 1, characterized in that: The dispersant is one or a combination of BYK-110 and Euka 710S; The solvent is a mixture of butanone and N-methylpyrrolidone, and the mass ratio of butanone to N-methylpyrrolidone is 3:

1.

8. The polyaniline electrostatic conductive coating according to claim 1, characterized in that: The amine value of the polyamide curing agent is 200-240 mgKOH / g.

9. A method for preparing the polyaniline electrostatic conductive coating according to any one of claims 1 to 8, characterized in that: The following steps are involved: The preparation process of component A is: A mixture of butanone and N-methylpyrrolidone is selected as the solvent, polyaniline and gemini surfactant are added to the N-methylpyrrolidone, stirring is started, heating to 40° C. to 60° C., stirring for a certain time, and then ultrasonically treating for a certain time to obtain a doped polyaniline dispersion; The epoxy resin, doped polyaniline dispersion, butanone and dispersant are uniformly dispersed at high speed; finally, the anti-rust pigment is added and dispersed at high speed until the fineness is ≤80μm, thus obtaining component A; The preparation process of component B is as follows: the polyamide curing agent is packaged.

10. The method for preparing the polyaniline electrostatic conductive coating according to claim 9, characterized in that: The preparation process of component A is: Add polyaniline and gemini surfactant to N-methylpyrrolidone, start stirring, heat to 40°C to 60°C, stir for 2 hours, and then ultrasonicate for 30 minutes to 60 minutes to obtain a doped polyaniline dispersion; The epoxy resin, doped polyaniline dispersion, butanone and dispersant are uniformly dispersed at high speed; finally, the anti-rust pigment is added and dispersed at high speed until the fineness is ≤80μm, thereby obtaining component A.

Images