Preparation method of p-phenylenediamine functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling surface paint

Abstract

This invention discloses a method for preparing a p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling surface paint. The method includes the following steps: First, natural graphite-like graphene carbon is prepared. p-phenylenediamine is used to functionalize the surface of the graphene-like carbon, which serves as a conductive medium and dispersant. This carbon is then uniformly mixed with epoxy resin to form a p-phenylenediamine-functionalized graphene-like carbon material dispersion. Functional additives, pigments, and fillers are added, and the mixture is dispersed at high speed until homogeneous, completing component B. Then, phenolic amine epoxy curing agent component A is added, and the mixture undergoes reaction and curing to form a paint film, finally yielding the p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling surface paint. The material prepared using this invention exhibits good antistatic properties and is simple to apply and inexpensive. It has broad application prospects in the coating of floors in workshops and venues requiring cleaning and antistatic properties, such as those in the pharmaceutical, electronics, instrumentation, textile, daily chemical, and food industries.

Description

Technical Field

[0001] This application relates to the field of antistatic epoxy self-leveling surface coating technology, and in particular to a method for preparing a p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling surface coating. Background Technology

[0002] Static electricity is an electrical energy that exists everywhere and at all times. It is a phenomenon caused by the accumulation of charge on the surface of an object when there is an imbalance of positive and negative charges in a local area. When charge accumulates on the surface of an object, static electricity is generated (Yao Taiping, 2021). Static electricity is characterized by high potential, low charge, strong environmental influence, and short duration (Zhang Hong, 2018), making it a "killer" of modern industry. Static electricity poses a significant threat to electronic devices. Static electricity causes many problems in industrial life. It generates electromagnetic waves that interfere with automatic instruments, and the charge makes products dusty in the workshop, which is not conducive to precision processing (Yin Liping and Song Yunjuan, 2016; Wang Han et al., 2019; Zou Li et al., 2018). Similar problems exist in pharmaceutical, electronics, instrumentation, textile, daily chemical, and food processing workshops, warehouses, laboratories, hospitals, public venues, offices, and even residential floors (Liu Chenglou, 2008), urgently requiring good electrostatic protection.

[0003] Static electricity poses hazards to the electronics industry, military, and energy storage and transportation sectors, necessitating high-performance cleaning and anti-static materials. Many measures have been taken to avoid static electricity problems. Anti-static concrete materials are used on stationary buildings, but their high construction costs limit their application. Anti-static coatings are used on the floors of stationary clean processing workshops, requiring high-performance anti-static epoxy floor coatings (Zhou Dunbai et al., 2007; Yao Taiping, 2021). Anti-static coatings are also needed on moving transportation equipment, especially during energy storage and transportation, where static electricity can cause dangers such as fires, requiring anti-static coatings to provide effective protection for oil and gas transportation and storage equipment (Shi Zhenghai, 2004).

[0004] With the rapid development of modern industry and the continuous improvement of people's living standards, antistatic epoxy self-leveling topcoat is needed for widespread antistatic purposes in factories, institutions and homes.

[0005] Antistatic properties are a practical function that works through the interaction of coatings, typically primer and topcoat. One method involves laying a conductive copper mesh or other metal mesh between the primer and topcoat (Yin Liping, 2015). However, the high cost of metal mesh limits its application. Therefore, a different approach is to uniformly distribute a conductive medium within the floor coating, controlling its resistivity to achieve an antistatic effect. When charge enters, it is immediately guided to a connected ground or other low-potential discharge point. Existing conductive media include metallic conductive materials, organic polymer conductive materials, and inorganic conductive materials.

[0006] Metal conductive powders have good conductivity, are colored, but have poor dispersibility and are easily oxidized. Conductive metal oxides have good conductivity, can be added in large quantities, and have good resistivity control. Conductive polymers, such as those doped with polyaniline, have good conductivity and corrosion resistance (Yin Liping, 2015), but poor weather resistance. Metal conductive materials, organic polymer conductive materials, and synthetic materials are expensive, limiting their application range. Organic polymer conductive materials have limited conductivity and limited antistatic effects.

[0007] Inorganic fillers such as precipitated barium sulfate, mica powder, talc powder, and quartz powder have good chemical stability (Liu Lixiang et al., 2012), but poor conductivity and compatibility with epoxy resins. Sufficient surface modification is usually required to achieve conductivity and other effects. For example, light-colored conductive mica powder prepared by modifying natural mica can be used as an additive in antistatic coatings, but the addition amount is very large, often requiring 20-25%. Therefore, antistatic coatings made with light-colored conductive mica powder have a thick coating and poor overall conductivity during application. Furthermore, they are prone to producing blind spots. These blind spots are non-conductive and cannot provide antistatic effects, affecting the overall antistatic performance. The addition of conductive mica powder increases the viscosity of the antistatic coating, worsens its processing performance, and increases the difficulty of application.

[0008] Among inorganic non-metallic materials, carbon materials, such as graphite and carbon black, have the best electrical conductivity. However, they are black in color, and when used in large quantities, the visual effect is not good.

[0009] Carbon materials have high conductivity and good antistatic effects; however, their conductivity varies with the structure of the carbon material, and consequently, their antistatic effect also changes. Currently, the commonly used carbon material is carbon black, which is primarily amorphous carbon with a disordered carbon atom structure, resulting in limited conductivity. Therefore, large quantities are needed to achieve the desired antistatic effect, and large quantities can even cause the entire floor coating to darken. Consequently, it is typically only used as a primer for antistatic epoxy self-leveling topcoats. When applying antistatic epoxy self-leveling topcoats, a two-layer structure is necessary: ​​a lower primer layer and an upper floor coating layer. The lower layer uses carbon black as a primer and acts as a conductive layer, while the upper floor coating layer requires the addition of conductive materials. This necessitates two applications—one primer and one topcoat—to achieve a good antistatic effect, increasing the complexity of the application process.

[0010] The optical properties of carbon materials are closely related to their structure. Graphite has high crystallinity, exhibiting a metallic luster and a silvery-gray appearance. Carbon black, being amorphous with poor crystallinity, appears black. Therefore, graphite has a better color effect than carbon black when used as a conductive medium, with colors ranging from dark to light. The regular arrangement of carbon atoms in graphite results in good conductivity, while the random arrangement of carbon atoms in carbon black leads to poor conductivity. To achieve the same conductivity, a greater amount of graphite is needed as a conductive medium than carbon black, making it less expensive compared to other carbon materials such as carbon fibers and carbon nanotubes.

[0011] Well-crystallized graphite exhibits good electrical conductivity; however, this conductivity is anisotropic, with high conductivity along the carbon layers and poor conductivity perpendicular to them, thus limiting its antistatic effect. Graphene-like carbons prepared from natural graphite, while possessing good electrical conductivity, exhibit poor dispersibility in epoxy floor coatings. The resulting graphite-based epoxy floor coatings show uneven conductivity, have blind spots, and thus have poor antistatic effects. Summary of the Invention

[0012] To address the problems existing in carbon graphite epoxy floor coatings, this patent invention provides a method for preparing a high-performance antistatic epoxy self-leveling topcoat with high conductivity, good dispersibility, three-dimensional network conductivity, and integrated primer and topcoat properties. This is a simple method for preparing a high-performance antistatic epoxy self-leveling topcoat with excellent antistatic effects.

[0013] This invention provides a method for preparing a p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling surface coating. The aim is to achieve the functionalization of natural graphite-based graphene-like materials through p-phenylenediamine functionalization. P-phenylenediamine introduces benzene-like rings onto the surface of the graphene-like carbon, improving the dispersibility of the natural graphite-based graphene-like carbon in epoxy resin and overcoming the drawback of easy agglomeration of nano-carbon in epoxy resin. Good dispersibility promotes the uniform distribution of the graphene-like carbon in the epoxy resin, ensuring uniform mixing between the graphene-like carbon and the epoxy resin. P-phenylenediamine is grafted onto the surface of the natural graphite-based graphene-like carbon, linking conductive functional groups perpendicular to the carbon atom layers on the graphene carbon surface, constructing a three-dimensional current conduction network together with the graphene carbon atom layers. Good dispersibility promotes the uniformity of the three-dimensional current conduction network constructed in the epoxy floor coating along the carbon atom layer direction, the perpendicular layer direction, and the p-phenylenediamine conductive functional groups. This uniform three-dimensional current conduction network enables the p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling surface paint to more effectively dissipate accumulated static charge, achieving excellent antistatic effects. Compared with the two-dimensional conductivity of ordinary graphite conductive materials, the three-dimensional current conduction spatial network prepared by this invention provides a high-performance antistatic protective epoxy self-leveling surface paint, and its high conductivity ensures its excellent antistatic performance.

[0014] The p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling topcoat prepared by this invention has excellent antistatic properties, avoiding the problems caused by static electricity in precision machining and industrial production, reducing the generation of electromagnetic waves, and minimizing interference with automatic instruments. It has broad application prospects in the coating of floors in workshops and venues requiring cleaning and antistatic properties in industries such as pharmaceuticals, electronics, instrumentation, textiles, daily chemicals, and food.

[0015] The technical solution provided by this invention is as follows:

[0016] A method for preparing a p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling topcoat specifically includes the following three steps:

[0017] 1) Graphene-like carbon materials are prepared using natural graphite;

[0018] 2) Add p-phenylenediamine to the graphene-like carbon material obtained in step 1) to functionalize its surface, and obtain p-phenylenediamine-functionalized graphene-like carbon;

[0019] 3) The p-phenylenediamine-functionalized graphene carbon obtained in step 2) is used as a conductive medium and dispersant material and added to epoxy resin to obtain p-phenylenediamine-functionalized graphene carbon antistatic epoxy self-leveling surface paint.

[0020] Furthermore, step 1) specifically involves the following steps:

[0021] 1-1) Using natural graphite as raw material, expanded graphite is produced through chemical intercalation, high-temperature expansion / microwave expansion;

[0022] 1-2) A combination of water washing, centrifugation, filtration, drying, ultrasonic dispersion, and centrifugal separation was used to obtain graphene-like carbon materials.

[0023] Furthermore, the specific process flow for preparing p-phenylenediamine-functionalized graphene carbon in step 2) is as follows:

[0024] 2-1) Weigh out graphene-like carbon powder, add deionized water, and disperse it by ultrasonication to obtain a graphene-like carbon suspension;

[0025] 2-2) Add diluted ammonia water to adjust the pH of the suspension to 9-12, and stir well;

[0026] 2-3) Heat rapidly to 90-100℃, add p-phenylenediamine, maintain the temperature, and filter;

[0027] 2-4) Wash with deionized water and ethanol to remove unreacted p-phenylenediamine, and dry the product in an oven at 80-105°C to obtain p-phenylenediamine-functionalized graphene-like carbon.

[0028] The weight ratio of graphene-like carbon powder to p-phenylenediamine is 1:0.01 to 1:100.

[0029] Furthermore, the preparation process for step 3) is as follows:

[0030] 3-1) Add the reactive diluent to the epoxy resin, add p-phenylenediamine functionalized graphene carbon material, disperse at high speed at 40-60℃ until well mixed, and prepare a p-phenylenediamine functionalized graphene carbon material dispersion; add functional additives, pigments, and fillers, disperse at high speed until well mixed, and complete component B.

[0031] 3-2) Add phenolic amine epoxy curing agent component A, react and cure to form a paint film, and obtain p-phenylenediamine functionalized natural graphite-based graphene carbon antistatic epoxy self-leveling surface paint.

[0032] Among them, p-phenylenediamine-functionalized graphene carbon materials account for 0.5-3.0 wt% of component B.

[0033] The present invention further provides a high-performance antistatic protective epoxy self-leveling surface paint prepared according to the above method.

[0034] This patented invention produces a p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling surface paint, a high-performance antistatic epoxy self-leveling surface paint capable of electrostatic protection. The p-phenylenediamine functionalizes the natural graphite-based graphene-like carbon, introducing benzene-like rings onto the surface of the graphene-like carbon. This improves the dispersibility of the natural graphite-based graphene-like carbon in epoxy resin, overcoming the drawback of easy agglomeration of nano-carbon in epoxy resin. The good dispersibility promotes the uniform distribution of the graphene-like carbon in the epoxy resin, ensuring uniform mixing between the graphene-like carbon and the epoxy resin. Furthermore, p-phenylenediamine is grafted onto the surface of the natural graphite-based graphene-like carbon, linking vertical carbon atom layer conductive functional groups to the graphene carbon surface, forming a three-dimensional current conduction network together with the graphene carbon atom layers. This good dispersibility promotes the uniformity of the three-dimensional current conduction network constructed in the epoxy floor coating along the carbon atom layer direction, the vertical direction, and the p-phenylenediamine conductive functional groups. This uniform three-dimensional current conduction network enables the p-phenylenediamine-functionalized graphene-like carbon antistatic epoxy self-leveling surface paint to more effectively dissipate accumulated static charge, achieving excellent antistatic effects. Compared with the two-dimensional conductivity of ordinary graphite conductive materials, the three-dimensional current conduction spatial network prepared by this invention provides a high-performance antistatic protective epoxy self-leveling surface paint, and its high conductivity ensures its excellent antistatic performance.

[0035] This patented invention produces a p-phenylenediamine-functionalized graphene-based antistatic epoxy self-leveling topcoat with excellent antistatic, antibacterial, and antifungal properties. At a coating thickness of 2mm, there are no blind spots. Application is simple, avoiding the complex processes typically used. It eliminates the need for conductive carbon black as a primer; the graphene-functionalized antistatic epoxy self-leveling topcoat is applied in a single step, replacing the previous two applications of primer and topcoat. The p-phenylenediamine-functionalized graphene-based carbon process significantly simplifies the application. It exhibits excellent flowability, exceeding that of light-colored conductive mica-doped antistatic epoxy self-leveling topcoat, resulting in epoxy floor coatings without blind spots. Compared to expensive carbon fibers and carbon nanotubes, p-phenylenediamine-functionalized graphene-based carbon is significantly cheaper.

[0036] The beneficial effects of this patented invention are:

[0037] This invention primarily utilizes p-phenylenediamine-functionalized graphene-like carbon as a conductive medium. The prepared p-phenylenediamine-functionalized graphene-like carbon antistatic epoxy self-leveling surface coating exhibits the following specific effects:

[0038] (1) Based on the high conductivity and anisotropic conductivity of graphite conductive materials, but poor dispersion of the medium, this patent invention provides a method for preparing a high-performance antistatic epoxy self-flowing surface paint with high conductivity, good dispersion, three-dimensional network conductivity, and a combination of primer and topcoat.

[0039] (2) Compared with the two-dimensional anisotropic conductivity of ordinary pure graphite, this invention prepares a high-performance antistatic and protective epoxy self-leveling surface paint with a three-dimensional current conduction network, resulting in better antistatic effects. Introducing benzene-like rings on the graphite surface improves the dispersibility of natural graphite-based graphene-like carbon in epoxy resin, overcoming its tendency to aggregate in epoxy resin. Good dispersibility promotes the uniform distribution of graphene-like carbon in epoxy resin, ensuring uniform mixing between the graphene-like carbon and epoxy resin. This invention functionalizes the surface of natural graphite-based graphene-like carbon, grafting p-phenylenediamine onto the graphene carbon surface to link vertical carbon atom layer conductive functional groups, which, together with the graphene carbon atom layers, construct a three-dimensional current conduction network. Good dispersibility promotes the uniformity of the three-dimensional current conduction network constructed in the epoxy floor coating in the carbon atom layer direction, the vertical direction, and the p-phenylenediamine conductive functional groups. This uniform three-dimensional current conduction network enables p-phenylenediamine-functionalized graphene-like carbon antistatic epoxy self-leveling surface paint to more effectively eliminate accumulated static charge, achieving excellent antistatic effects.

[0040] (3) Compared with expensive metal materials, p-phenylenediamine-functionalized graphene carbon is less prone to oxidation and has good corrosion resistance. Compared with carbon black, it is easier to apply. The color becomes lighter, changing from black to metallic gray. The amount used is reduced, so the color becomes lighter. Compared with carbon materials such as carbon fiber and carbon nanotubes, it is inexpensive.

[0041] (4) The application of p-phenylenediamine-functionalized graphene carbon antistatic epoxy self-leveling topcoat is simple. It avoids the complex processes commonly used, eliminates the need for conductive carbon black as a primer, and achieves the effect of combining primer and topcoat in one step. The application process of the p-phenylenediamine-functionalized graphene carbon antistatic epoxy self-leveling topcoat invented in this patent is simple. The primer and topcoat are applied in one step, which previously required two steps: one primer and one topcoat. The graphene is applied in one step, greatly simplifying the application process.

[0042] (5) The p-phenylenediamine functionalized graphene carbon antistatic epoxy self-leveling surface paint has good flowability, which is greater than that of light-colored conductive mica powder doped antistatic epoxy self-leveling surface paint. The epoxy floor coating manufactured has no blind spots.

[0043] (6) The preparation method of this invention is simple and inexpensive, and the prepared p-phenylenediamine-functionalized graphene carbon has the advantages of excellent conductivity. As a conductive medium, it imparts current conduction and removal properties to antistatic epoxy self-flowing surface paint, and has excellent antistatic effect.

[0044] This patent discloses a method for preparing a high-performance antistatic epoxy self-leveling topcoat with high conductivity, good dispersibility, three-dimensional conductive network, and integrated primer and topcoat properties. This method offers a simple application and excellent antistatic effect. The aim is to graft p-phenylenediamine onto the surface of natural graphite-based graphene-like carbon, uniformly mixing the graphene-like carbon with epoxy resin. This links vertical carbon atom layer conductive functional groups onto the graphene carbon surface, constructing a three-dimensional current conduction network with the graphene carbon atom layers. This effectively eliminates accumulated static charge, achieving an antistatic protective epoxy self-leveling topcoat. The p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling topcoat prepared by this method exhibits good antistatic properties, simple application, and low cost. It has broad application prospects in the coating of floors in workshops and venues requiring cleaning and antistatic properties in industries such as pharmaceuticals, electronics, instrumentation, textiles, daily chemicals, and food. Attached Figure Description

[0045] To more clearly illustrate the specific embodiments of this application or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0046] Figure 1 Process diagram for preparing p-phenylenediamine-functionalized graphene-based antistatic epoxy self-leveling surface coating.

[0047] Figure 2 Schematic diagram of the structure of p-phenylenediamine-functionalized graphene-based antistatic epoxy self-leveling surface paint. Detailed Implementation

[0048] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0050] p-Phenylenediamine is an organic compound with the chemical formula C6H8N2. It is one of the simplest aromatic diamines and a widely used intermediate. This patent uses p-phenylenediamine as a modifier for natural graphite-based graphene carbon to functionalize its surface, enabling better bonding with epoxy resin and thus better preparing p-phenylenediamine-functionalized natural graphite-based graphene carbon antistatic epoxy self-leveling surface paint.

[0051] The present application will be further described in detail below with reference to specific embodiments and comparative examples.

[0052] like Figure 1 As shown, in a specific embodiment 1 of the present invention, p-phenylenediamine functionalized graphene carbon material is used to prepare p-phenylenediamine functionalized graphene carbon antistatic epoxy self-leveling surface paint.

[0053] 1) Preparation of natural graphite-based graphene-like carbon

[0054] Using natural graphite as raw material, graphene-like carbon based on natural graphite was prepared by a combination of chemical intercalation, high-temperature expansion / microwave expansion, ultrasonic dispersion and centrifugal separation.

[0055] The process for preparing graphene from natural graphite is as follows: chemical intercalation of natural graphite, microwave expansion to produce expanded graphite, washing, centrifugation, filtration, drying, ultrasonic dispersion, and centrifugal separation to obtain graphene-like nanomaterials, namely natural graphite-based graphene-like carbon. Detailed process flow and parameters are as follows;

[0056] The mass ratio of phosphorus pentoxide to graphite was 1.25, the mass ratio of potassium permanganate to graphite was 0.35, the volume ratio of nitric acid to graphite was 1.25 mL / g, the nitric acid mass fraction was 68%, the reaction time was 80 min, the reaction temperature was 25℃, the expansion time was 40 s, and the microwave power was 800 W. Phosphorus pentoxide was mixed with an equal mass of deionized water, cooled, and then nitric acid was added. Natural graphite and solid potassium permanganate were then added, and the mixture was stirred at 25℃ for 80 min on a magnetic stirrer. The mixture was filtered until the filtrate was colorless, dried in a constant-temperature electric furnace, and expanded graphite was obtained. This expanded graphite was then expanded for 40 s under microwave power of 800 W. The expanded graphite was washed, centrifuged, filtered, dried, ultrasonically dispersed, and centrifuged again to obtain graphene-like nanomaterials, yielding natural graphite-based graphene-like carbon, which was then ready for use.

[0057] 2) Preparation of p-phenylenediamine-functionalized graphene-like carbon

[0058] Further, in step 1), p-phenylenediamine is added to the natural graphite-based graphene carbon to functionalize its surface, thus preparing p-phenylenediamine-functionalized graphene carbon.

[0059] The preparation process of p-phenylenediamine-functionalized graphene carbon is as follows: ultrasonic crushing → reflux cooling → filtration and drying.

[0060] Weigh 10 mg of natural graphite-based graphene carbon powder, add 100 mL of deionized water, and ultrasonically disperse to obtain a natural graphite-based graphene carbon suspension. Adjust the pH of the suspension to 9–12 by adding diluted ammonia dropwise, stir until homogeneous, and rapidly heat to 90–100 °C. Add 0.1 g of p-phenylenediamine and maintain the temperature for 3 hours. Then, filter and wash with deionized water and ethanol to remove unreacted p-phenylenediamine. Dry the product in an oven at 80–105 °C to obtain p-phenylenediamine-functionalized graphene carbon for later use.

[0061] 3) Preparation of p-phenylenediamine-functionalized graphene-based antistatic epoxy self-leveling topcoat

[0062] Further, in step 2), p-phenylenediamine-functionalized graphene carbon is added to the epoxy resin as a conductive medium to prepare a p-phenylenediamine-functionalized graphene carbon antistatic epoxy self-leveling topcoat. The preparation process is as follows: First, an active diluent is added to the epoxy resin, followed by the p-phenylenediamine-functionalized graphene carbon material. The mixture is dispersed at high speed at 45°C until homogeneous, forming a p-phenylenediamine-functionalized graphene carbon material dispersion. Various functional additives, pigments, and fillers are then added, and the mixture is dispersed at high speed until homogeneous, completing component B. Component A (phenolic amine epoxy curing agent) is then added, and the mixture is reacted and cured to form a paint film, obtaining a p-phenylenediamine-functionalized natural graphite-based graphene carbon antistatic epoxy self-leveling topcoat.

[0063] When the amount of p-phenylenediamine-functionalized graphene carbon added to component B is 1.5 wt%, the surface resistivity of the sample material is 1.25 × 10⁻⁶. 5 Ω·cm. This is far less than the surface resistivity of antistatic epoxy self-leveling surface paint (National Standard 22374-2018), which is ≥5×10⁻⁶. 4 ~<1×10 6 Ω·cm.

[0064] The obtained p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling surface coating exhibits excellent antistatic effects and can meet the surface resistivity requirements of antistatic materials in the standard.

[0065] Comparative Example 1: Natural Graphite-Based Graphene-like Carbon

[0066] This embodiment directly employs the preparation method of natural graphite-based graphene-like carbon antistatic epoxy self-leveling topcoat to prepare natural graphite-based graphene-like carbon antistatic epoxy self-leveling topcoat.

[0067] 1) Preparation of natural graphite-based graphene-like carbon

[0068] Using natural graphite as raw material, graphene-like carbon based on natural graphite was prepared by a combination of chemical intercalation, high-temperature expansion / microwave expansion, ultrasonic dispersion and centrifugal separation.

[0069] The process for preparing graphene from natural graphite is as follows: chemical intercalation of natural graphite, microwave expansion to produce expanded graphite, washing, centrifugation, filtration, drying, ultrasonic dispersion, and centrifugal separation to obtain graphene-like nanomaterials, namely natural graphite-based graphene-like carbon. Detailed process flow and parameters are as follows;

[0070] The mass ratio of phosphorus pentoxide to graphite was 1.25, the mass ratio of potassium permanganate to graphite was 0.35, the volume ratio of nitric acid to graphite was 1.25 mL / g, the nitric acid mass fraction was 68%, the reaction time was 80 min, the reaction temperature was 25℃, the expansion time was 40 s, and the microwave power was 800 W. Phosphorus pentoxide was mixed with an equal mass of deionized water, cooled, and then nitric acid was added. Natural graphite and solid potassium permanganate were then added, and the mixture was stirred at 25℃ for 80 min on a magnetic stirrer. The mixture was filtered until the filtrate was colorless, dried in a constant-temperature electric furnace, and expanded graphite was obtained. This expanded graphite was then expanded for 40 s under microwave power of 800 W. The expanded graphite was washed, centrifuged, filtered, dried, ultrasonically dispersed, and centrifuged again to obtain graphene-like nanomaterials, yielding natural graphene-based graphene-like carbon.

[0071] 2) Preparation of natural graphite-based graphene-like carbon antistatic epoxy self-leveling topcoat

[0072] Further, in step 2), graphene carbon is added to the epoxy resin as a conductive medium to prepare a natural graphene-based antistatic epoxy self-leveling surface paint. The preparation process is as follows:

[0073] First, an active diluent is added to the epoxy resin, followed by natural graphite-based graphene carbon. The mixture is then dispersed at high speed at 45°C until homogeneous, forming a p-phenylenediamine-functionalized graphene carbon material dispersion. Various functional additives, pigments, and fillers are then added, and the mixture is dispersed at high speed until homogeneous, completing component B. Component A (phenolic amine epoxy curing agent) is then added to allow for reaction and curing, forming a paint film to obtain a natural graphite-based graphene carbon antistatic epoxy self-leveling topcoat.

[0074] When the amount of natural graphene-based carbon in component B is 1.5 wt%, the surface resistivity of the sample material is 3.25 × 10⁻⁶. 6Ω·cm. The surface resistivity of antistatic epoxy self-leveling surface paint (National Standard 22374-2018) is ≥5×10⁻⁶ Ω·cm. 4 ~<1×10 6 Ω·cm.

[0075] The obtained natural graphite-based graphene-like carbon antistatic epoxy self-leveling surface coating exhibits good antistatic effect and can meet the surface resistivity requirements of antistatic materials in the standard.

[0076] Comparative Example 2: Graphite

[0077] This embodiment directly employs the preparation method of graphite-doped antistatic epoxy self-leveling surface paint to prepare graphite antistatic epoxy self-leveling surface paint.

[0078] Graphite was used as a conductive medium and added to epoxy resin to prepare graphite antistatic functional epoxy flooring. The preparation process is as follows: First, an active diluent was added to the epoxy resin, followed by natural graphite. The mixture was dispersed at high speed at 45°C until homogeneous, forming a graphite dispersion. Various functional additives, pigments, and fillers were then added and dispersed at high speed until homogeneous, completing component B. Component A (phenolic amine epoxy curing agent) was then added for reaction and curing to form a paint film, resulting in a p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling surface paint.

[0079] When the amount of graphite in component B is 1.5 wt%, the surface resistivity of the sample material is 1.06 × 10⁻⁶. 8 Ω·cm. The surface resistivity of antistatic epoxy self-leveling surface paint (National Standard 22374-2018) is ≥5×10⁻⁶ Ω·cm. 4 ~<1×10 6 Ω·cm.

[0080] The obtained graphite carbon antistatic epoxy self-leveling surface paint shows a certain antistatic effect.

[0081] Comparative Example 3: Carbon Black

[0082] This embodiment directly employs the preparation method of carbon black-doped antistatic epoxy self-leveling topcoat to prepare p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling topcoat.

[0083] Carbon black is used as a conductive medium and added to epoxy resin to prepare carbon black antistatic functional epoxy flooring. Further, in step 2), carbon black is used as a conductive medium and added to epoxy resin to prepare carbon black antistatic epoxy self-leveling topcoat. The preparation process is as follows: First, an active diluent is added to the epoxy resin, then carbon black is added, and the mixture is dispersed at high speed at 45°C until homogeneous, forming a carbon black dispersion. Various functional additives, pigments, and fillers are added, and the mixture is dispersed at high speed until homogeneous, completing component B. Component A (phenolic amine epoxy curing agent) is added to react and cure, forming a paint film to obtain the carbon black antistatic epoxy self-leveling topcoat.

[0084] When the amount of carbon black in component B is 1.5 wt%, the surface resistivity of the sample material is 3.75 × 10⁻⁶. 9 Ω·cm. The surface resistivity of the antistatic epoxy self-leveling surface paint, as per national standard 22374-2018, is ≥5×10⁻⁶ Ω·cm. 4 ~<1×10 6 Ω·cm.

[0085] The obtained carbon black epoxy self-leveling topcoat has poor antistatic properties.

[0086] Comparative Example 4: Pure Epoxy Self-Leveling Topcoat

[0087] This embodiment directly uses the preparation method of undoped antistatic epoxy flooring to prepare pure epoxy self-leveling surface paint.

[0088] Epoxy flooring is made from pure epoxy resin. The preparation process is as follows: First, an active diluent is added to the epoxy resin, then various functional additives are added and mixed. After mixing, pigments and fillers are added and dispersed at high speed until the mixture is homogeneous, completing component B. Then, component A (phenolic amine epoxy curing agent) is added to react and cure, forming a paint film, thus obtaining a pure epoxy resin antistatic epoxy self-leveling topcoat.

[0089] The surface resistivity of pure epoxy resin antistatic self-leveling topcoat is 1.50 × 10⁻⁶. 14 Ω·cm, which is much greater than the surface resistivity of antistatic epoxy self-leveling surface paint (National Standard 22374-2018) which is ≥5×10⁻⁶. 4 ~<1×10 6 Ω·cm, which does not meet the surface resistivity requirements for antistatic materials in the standard.

[0090] Comparative Example 5: Carbon Fiber Antistatic Epoxy Self-Leveling Topcoat

[0091] This embodiment directly uses the preparation method of undoped antistatic epoxy flooring to prepare carbon fiber antistatic epoxy self-leveling surface paint.

[0092] Antistatic epoxy self-leveling topcoat is made using carbon fiber. The preparation process is as follows:

[0093] First, an active diluent is added to the epoxy resin, followed by carbon fiber. The mixture is then dispersed at high speed at 45°C until homogeneous, forming a carbon fiber dispersion. Various functional additives, pigments, and fillers are added, and the mixture is dispersed at high speed until homogeneous, completing component B. Component A (phenolic amine epoxy curing agent) is then added to allow for reaction and curing, forming a paint film to obtain a carbon fiber antistatic epoxy self-leveling topcoat.

[0094] When the amount of carbon fiber in component B is 9.0 wt%, the surface resistivity of the carbon fiber antistatic epoxy self-leveling topcoat is 7.5 × 10⁻⁶. 5 Ω·cm. The surface resistivity of antistatic epoxy self-leveling surface paint (National Standard 22374-2018) is ≥5×10⁻⁶ Ω·cm. 4 ~<1×10 6 Ω·cm. Meets the surface resistivity requirements for antistatic materials in the standard; however, carbon fiber is expensive.

[0095] Comparative analysis of the examples and comparative examples

[0096] The examples and comparative examples prepared according to this invention are summarized in Table 1 below. Based on this, a comparative analysis is conducted on the preparation method of the p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling surface paint of this patent invention.

[0097] Table 1. Comparison of Examples and Comparative Examples of p-phenylenediamine Functionalized Natural Graphite-based Graphene-like Carbon Antistatic Epoxy Self-leveling Topcoat

[0098]

[0099]

[0100] Comparative analysis revealed that in the preparation of antistatic epoxy self-leveling surface paint, different conductive media resulted in products with different conductivity properties and significant differences in surface resistivity.

[0101] In the embodiments and comparative examples prepared by this invention, the surface resistivity of the obtained epoxy self-leveling surface paints is arranged from largest to smallest as follows:

[0102] Pure epoxy resin > Carbon black / epoxy self-leveling topcoat > Graphite / epoxy self-leveling topcoat > Natural graphite-based graphene-like carbon / epoxy self-leveling topcoat > p-phenylenediamine-functionalized natural graphite-based graphene-like carbon / epoxy self-leveling topcoat

[0103] Comparative analysis of the surface resistivity of the examples and comparative examples revealed that the p-phenylenediamine-functionalized natural graphite-based graphene-like carbon / epoxy self-leveling surface paint prepared in this invention has the lowest surface resistivity. In other words, the p-phenylenediamine-functionalized natural graphite-based graphene-like carbon / epoxy self-leveling surface paint prepared in this invention has the best electrical conductivity.

[0104] The surface resistivity of all examples and comparative examples with added conductive media was compared and analyzed. Both were used as conductive media in the same amount in epoxy self-leveling surface coatings, and their surface resistivity was compared. The surface resistivity of epoxy resin self-leveling surface coatings with added carbon black, graphite, carbon fiber, natural graphite-based graphene-like carbon, and p-phenylenediamine-functionalized natural graphite-based graphene-like carbon were all lower than that of pure epoxy resin self-leveling surface coatings without any conductive media. This indicates that the addition of conductive media reduces the resistivity of epoxy self-leveling surface coatings, suggesting that the addition of conductive media improves the conductivity of epoxy self-leveling surface coatings.

[0105] The surface resistivity of epoxy self-leveling surface coatings with different carbon structures, namely carbon black and graphite, was compared and analyzed. Both were used as conductive media in the same amount in epoxy self-leveling surface coatings, and their surface resistivity was compared. The surface resistivity of the epoxy self-leveling surface coating with added graphite was lower than that with added carbon black. This indicates that the surface resistivity of the well-crystallized graphite epoxy self-leveling surface coating is lower than that of the carbon black epoxy self-leveling surface coating. This demonstrates that the higher the degree of crystallinity of the carbon material, the better its conductivity. Using highly crystalline carbon materials as conductive media is beneficial for reducing the resistivity of epoxy self-leveling surface coatings and improving their conductivity.

[0106] The surface resistivity of epoxy self-leveling surface coatings with added natural graphite and natural graphite-based graphene carbon was compared and analyzed. Both were used as conductive media in equal amounts in epoxy self-leveling surface coatings, and their surface resistivity was compared. The surface resistivity of the epoxy self-leveling surface coating with added natural graphite-based graphene carbon was lower than that with added natural graphite. This indicates that the surface resistivity of natural graphite-based graphene carbon is lower than that of natural graphite. This demonstrates that the conductivity of natural graphite-based graphene carbon is superior to that of natural graphite. Using natural graphite-based graphene carbon reduces the resistivity and improves the conductivity of natural graphite-based epoxy self-leveling surface coatings.

[0107] The surface resistivity of epoxy self-leveling surface coatings with added natural graphene-like carbon and p-phenylenediamine-functionalized natural graphene-like carbon was compared. Both were used as conductive media in equal amounts in epoxy self-leveling surface coatings, and their surface resistivity was compared. The surface resistivity of the epoxy self-leveling surface coating with p-phenylenediamine-functionalized natural graphene-like carbon was lower than that of the coating without p-phenylenediamine functionalization. This indicates that the surface resistivity of the epoxy self-leveling surface coating with p-phenylenediamine functionalization is lower than that of the coating without p-phenylenediamine functionalization. This proves that the conductivity of p-phenylenediamine functionalized natural graphene-like carbon is superior to that of the coating without p-phenylenediamine functionalization. Functionalization of natural graphite-based graphene-like carbon with p-phenylenediamine reduced the resistivity of natural graphite-based graphene-like carbon-based epoxy self-leveling surface coatings. This indicates that p-phenylenediamine functionalization of natural graphite-based graphene-like carbon significantly improves the conductivity of natural graphite-based epoxy self-leveling surface coatings.

[0108] A comparative analysis of the surface resistivity of epoxy self-leveling surface coatings with added carbon fiber and those with p-phenylenediamine-functionalized natural graphite-based graphene-like carbon was conducted. The surface resistivity of the epoxy self-leveling surface coating with added carbon fiber was lower than that of both the natural graphite-based and p-phenylenediamine-functionalized natural graphite-based graphene-like carbon coatings. However, the p-phenylenediamine-functionalized natural graphite-based graphene-like carbon coating exhibited higher performance, indicating that a lower addition amount can achieve the same conductivity. Comparative analysis also showed that p-phenylenediamine-functionalized natural graphite-based graphene-like carbon is more cost-effective than the carbon fiber antistatic epoxy self-leveling surface coating, and the lower addition amount is more conducive to pigment modulation, resulting in a better color experience.

[0109] In summary, a comparative analysis of the surface resistivity of the embodiments and comparative examples revealed that, using the same conductive medium and the same addition amount in epoxy self-leveling surface coatings, the surface resistivity of the p-phenylenediamine-functionalized natural graphite-based graphene-like carbon epoxy self-leveling surface coating prepared in this invention was the lowest. In other words, the p-phenylenediamine-functionalized natural graphite-based graphene-like carbon epoxy self-leveling surface coating prepared in this invention exhibits the best conductivity. The surface resistivity of the p-phenylenediamine-functionalized natural graphite-based graphene-like carbon epoxy self-leveling surface coating prepared in this invention is lower than that of the unfunctionalized natural graphite-based graphene-like carbon epoxy self-leveling surface coating, lower than that of the unfunctionalized, non-graphene-carbonized natural graphite epoxy self-leveling surface coating, and also lower than that of the poorly crystallized amorphous carbon black epoxy self-leveling surface coating. This demonstrates that the present invention uses highly crystalline natural graphite as raw material to prepare natural graphite-based graphene-like carbon, and then functionalizes it with p-phenylenediamine to prepare p-phenylenediamine-functionalized graphene-like carbon. Using this as a conductive medium, a p-phenylenediamine-functionalized natural graphite-based graphene-like carbon / epoxy self-leveling surface coating is prepared. This significantly reduces the surface resistivity of the epoxy self-leveling surface coating, ensuring its high conductivity. Good conductivity is the guarantee of the excellent antistatic effect of the epoxy self-leveling surface coating.

[0110] The p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling surface coating prepared by this invention exhibits excellent antistatic effects. This invention grafts p-phenylenediamine conductive functional groups onto the surface of natural graphite-based graphene-like carbon, linking them vertically to the carbon atom layers. These groups, together with the graphene carbon atom layers, construct a three-dimensional current conduction network. The good dispersibility promotes the uniformity of the three-dimensional conduction network in the epoxy self-leveling surface coating, enabling the p-phenylenediamine-functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling surface coating of this patent to more effectively eliminate accumulated static charge, achieving excellent antistatic effects.

[0111] When the amount of p-phenylenediamine-functionalized natural graphene-based carbon added is 1.5 wt%, the surface resistivity of the obtained material is 1.25 × 10⁻⁶. 5 Ω·cm, which meets the surface resistivity requirements for antistatic materials in the standard.

[0112] References

[0113] Shi Zhenghai, Zeng Fandi. Development of light-colored conductive filler [J]. Adhesion, 2002, (6): 40-42.

[0114] Liu Chenglou. Formulation and application of antistatic, antibacterial and odor-removing water-based epoxy floor coatings [J]. Chemical Building Materials, 2008, 24(5):15-17.

[0115] Liu, Lixiang; Wen, Xiaomeng; Wang, Zheng, et al. Advances in the application of epoxy floor coatings [J]. Thermosetting Resins, 2012, 27(1):48-52.

[0116] Wang Han, Zhang Qian, Bi Zhigong. Epoxy resin and its application in building floor coatings [J]. Chemical Technology, 2019, 27(2):74-78. Yao Taiping. Study on antistatic properties of graphene / epoxy resin composites [D]. Jilin: Northeast Electric Power University, 2021.

[0117] Yin Liping. Application of intelligent coating system for interior walls [J]. China Coatings, 2015, 30(2): 27-30.

[0118] Zhang Hong. The hazards of static electricity to electronic components and effective protection [J]. Electronic Technology and Software Engineering, 2018, 132(10): 110-111. Zou Li, Zou Lin, Liu Xiaofeng, et al. Preparation and technical application progress of waterborne epoxy resin coatings [J]. Coatings and Applications, 2018, 48(1): 7-11. Zhou Dunbai, Zhou Zihu, Jia Demin. Research and application progress of epoxy floor coatings [J]. China Coatings, 2007, 22(10): 17-19, 22.

Claims

1. A method for preparing p-phenylenediamine functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling floor paint, specifically comprising the following steps: 1) preparing graphene-like carbon material using natural graphite; 2) adding p-phenylenediamine to the graphene-like carbon material obtained in step 1), grafting p-phenylenediamine on the surface of graphene-like carbon, linking vertical carbon atomic layer conductive functional groups on the surface of graphene-like carbon, and constructing a three-dimensional current conduction network together with the graphene carbon atomic layer, to obtain p-phenylenediamine functionalized graphene-like carbon; the specific preparation process is as follows: 2-1) weighing graphene-like carbon powder, adding deionized water, and performing ultrasonic dispersion to obtain graphene-like carbon suspension; 2-2) adding diluted ammonia water to adjust the pH value of the suspension to 9-12, and stirring uniformly; 2-3) heating to rapidly warm up to 90-100℃, adding p-phenylenediamine, and holding, and then filtering; 2-4) washing with deionized water and ethanol to remove unreacted p-phenylenediamine, drying the product in an oven at 80-105℃, and obtaining p-phenylenediamine functionalized graphene-like carbon; 3) adding the p-phenylenediamine functionalized graphene-like carbon obtained in step 2) as conductive medium and dispersant material into epoxy resin to obtain p-phenylenediamine functionalized graphene-like carbon antistatic epoxy self-leveling floor paint, and the specific preparation process is as follows: 3-1) Add active diluent to epoxy resin, add p-phenylenediamine functionalized graphenelike carbon material, 40~60 o C, high-speed dispersion to mix and mix, make p-phenylenediamine functionalized graphenelike carbon material dispersion liquid, add functional adjuvant, pigment, filler, high-speed dispersion to mix and mix, complete B component; 3-2) adding phenalkamine epoxy curing agent component A, and performing reaction curing to form paint film, and obtaining p-phenylenediamine functionalized natural graphite-based graphene-like carbon antistatic epoxy self-leveling floor paint.

2. The production method according to claim 1, wherein Step 1) specifically comprises: 1-1) using natural graphite as raw material, preparing expanded graphite through chemical intercalation, high-temperature expansion / microwave expansion, 1-2) washing with water, centrifuging, filtering, drying, and combining ultrasonic dispersion and centrifugal separation to obtain graphene-like carbon material.

3. The production method according to claim 1, wherein In step 2), the weight ratio of graphene-like carbon powder to p-phenylenediamine is 1:0.01-1:

100.

4. The production method according to claim 1, wherein The p-phenylenediamine functionalized graphene-like carbon material accounts for 0.5-3.0wt% of component B.

5. A high-performance antistatic protective antistatic epoxy self-leveling floor paint prepared according to the preparation method of any one of claims 1-4.

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