Conductive oil-based paint and method for producing the same

Abstract

The application belongs to the technical field of conductive paint, and specifically discloses a conductive oil-based paint and a preparation method thereof.The conductive oil-based paint comprises the following raw materials in parts by weight: 12-15 parts of styrene-butadiene-styrene block copolymer, 45-50 parts of oil-based acrylic resin, 4-6 parts of chlorinated polypropylene, 10-15 parts of conductive filler, 3-5 parts of hydrophobic titanium dioxide, 0.3-0.5 parts of defoaming agent, 15-20 parts of n-butanol, 30-40 parts of dimethylbenzene, 0.5-1.0 parts of antioxidant, and 10-15 parts of cyclohexanone; the conductive filler comprises graphene, Ag-Al composite filler, polypyrrole, and high-molecular dispersant BYK-2150, and gas-phase silicon dioxide.The multiple components of the application are combined to improve the uniformity and adhesion of the coating, and improve the water resistance, wear resistance and peeling resistance of the coating.

Description

Technical Field

[0001] This application relates to the technical field of conductive coatings, and in particular to a conductive oil-based coating and its preparation method. Background Technology

[0002] Conductive coatings are special functional coatings that can conduct electricity. Applying conductive coatings to insulating surfaces such as plastics and glass enables these materials to conduct electricity. Conductive coatings can be classified into water-based and oil-based types. Oil-based conductive coatings are more commonly used in high-end coating applications for plastics, metals, and composite materials due to their dense film formation, strong adhesion, excellent water and weather resistance, and wide adaptability to substrates.

[0003] Existing oil-based conductive coatings typically include film-forming substances, conductive fillers, organic solvents, and functional additives. The film-forming substance forms the coating's framework, possessing strong adhesion, corrosion resistance, and good mechanical properties. Conductive fillers are usually carbon-based, meeting standard antistatic requirements. Organic solvents dissolve the resin, making the coating a liquid suitable for application. Functional additives act as modifiers, ensuring the coating's uniformity and stability.

[0004] For non-polar substrates such as polypropylene, ordinary conductive coatings have insufficient adhesion and are prone to peeling and flaking. At the same time, the coating is easily damaged during bending and friction, which affects the long-term reliability.

[0005] Therefore, developing a conductive oil-based coating with excellent film-forming properties, strong adhesion to non-polar substrates, stable and adjustable conductivity, and good application and storage performance is of great practical significance and application value. Summary of the Invention

[0006] To improve the problem of insufficient coating adhesion leading to peeling, this application provides a conductive oil-based coating and its preparation method.

[0007] This application provides a conductive oil-based coating, employing the following technical solution: A conductive oil-based coating, by weight, comprises the following raw materials: 12-15 parts of styrene-butadiene-styrene block copolymer, 45-50 parts of oil-based acrylic resin, 4-6 parts of chlorinated polypropylene, 10-15 parts of conductive filler, 3-5 parts of hydrophobic titanium dioxide, 0.3-0.5 parts of defoamer, 15-20 parts of n-butanol, 30-40 parts of xylene, 0.5-1.0 parts of antioxidant, and 10-15 parts of cyclohexanone; The conductive fillers include graphene, Ag-Al composite filler, polypyrrole, high molecular weight dispersant BYK-2150, and fumed silica.

[0008] By adopting the above technical solution, styrene-butadiene-styrene block copolymer (SBS) is used as an elastomer modifier to improve the coating's toughness, bending resistance, and crack resistance. It is compatible with oil-based acrylic resin and chlorinated polypropylene, forming a resin system that combines hardness and flexibility. Oil-based acrylic resin serves as the main film-forming resin, providing the coating with basic hardness, gloss, weather resistance, and chemical resistance. It forms a hard-soft complementary structure with the styrene-butadiene-styrene block copolymer, resulting in a dense film and a balanced strength and toughness. The chlorine atoms in the chlorinated polypropylene molecular chain have good affinity with the oil-based acrylic resin and are also compatible with the styrene-butadiene-styrene block copolymer, effectively preventing phase separation, improving coating uniformity and adhesion, and enhancing the coating's water resistance, abrasion resistance, and peel resistance.

[0009] Hydrophobic titanium dioxide provides whiteness and hiding power, while the hydrophobic surface treatment makes it easier to disperse in oily systems, and also improves the weather resistance and anti-chalking ability of the coating film. Defoamers prevent pinholes, craters, and pitting in the coating, ensuring a dense and smooth surface. n-Butanol adjusts the polarity balance of the solvent system, improving the solubility stability of acrylic resins; xylene, as the main solvent, has strong solubility for SBS and chlorinated polypropylene; cyclohexanone enhances the solubility for acrylic resins and chlorinated polypropylene. Antioxidants inhibit the thermal oxidative degradation of the butadiene segment in SBS during processing and use, extending the coating's service life.

[0010] In conductive fillers, graphene possesses extremely high specific surface area and conductivity, constructing a highly efficient conductive network that significantly improves conductivity and enhances coating strength, wear resistance, thermal conductivity, and dimensional stability. Ag-Al composite fillers provide conductive pathways, reduce surface resistivity, and synergize with graphene to achieve high conductivity. Polypyrrole, a conductive polymer, supplements the conductive pathways, improves conductivity uniformity, fills the gaps between graphene sheets and Ag-Al particles, enhances the density and isotropy of the conductive network, improves the dispersion of inorganic conductive fillers, reduces agglomeration, and improves coating stability and wear resistance. The polymeric dispersant BYK 2150 provides strong dispersion, anti-settling, and anti-agglomeration properties for graphene, Ag, Al, and polypyrrole, improving coating storage stability and ensuring long-term consistent conductivity. Fumed silica prevents conductive filler sedimentation, enhances system stability, strengthens coating hardness and density, and imparts thixotropic properties to the coating.

[0011] The coating's various components are formulated using SBS and acrylic resins, with chlorinated polypropylene used to address polarity differences, achieving a balance between flexibility and hardness. A three-dimensional, multi-scale conductive network of graphene, Ag-Al, and polypyrrole is constructed, balancing conductivity efficiency with filler cost. Dispersants are used for high specific surface area fillers, while fumed silica is used for high-density fillers, addressing the two core issues of dispersion and sedimentation respectively. The mixed solvent balances the solubility, volatility gradient, and application adaptability of each resin, ensuring good wet film leveling, defect-free dry film, and guaranteeing the coating's abrasion resistance, corrosion resistance, and durability.

[0012] Preferably, the mass ratio of graphene, Ag-Al composite filler, and polypyrrole is 1:2-3:0.8-1.2.

[0013] By employing the above technical solution, graphene forms conductive bridges in the coating, connecting Ag-Al and polypyrrole particles, reducing contact resistance, and significantly improving the coating's crack resistance and barrier properties. Ag-Al composite filler, as high-density, highly conductive particles, forms a backbone conductive network in the coating, providing a low-resistance main pathway and enhancing the film's wear resistance and corrosion resistance. Polypyrrole fills the gaps between Ag-Al particles and between graphene sheets, forming numerous micro-contact points, upgrading the conductive network to multi-point contact and interfacial wetting, significantly reducing the percolation threshold and improving conductivity uniformity. The three-component mixture constructs a three-dimensional conductive network with a micron-scale framework (Ag-Al), submicron-scale filler (polypyrrole), and nano-bridges (graphene), achieving high conductivity and isotropy with low filler content. Polypyrrole and graphene synergistically inhibit Ag-Al sedimentation and corrosion, improving the conductive network's mechanical stability, wear resistance, and environmental durability.

[0014] Preferably, the Ag-Al composite filler is composed of aluminum powder, silane coupling agent, and chlorinated polypropylene, and the aluminum powder is surface-plated with silver by magnetron sputtering.

[0015] By adopting the above technical solution, aluminum powder serves as the core matrix, providing a lightweight and low-cost metal skeleton. This significantly reduces the filler's specific gravity and coating weight while ensuring conductivity, and also promotes suspension stability. A dense and uniform silver layer is formed on the aluminum powder surface through magnetron sputtering, ensuring the composite filler has excellent conductivity and is not easily peeled off.

[0016] The silane coupling agent, after hydrolysis, forms a chemical bond with the hydroxyl groups on the silver layer surface at one end (alkoxy group), while the other end (epoxy group, acryloyloxy group, etc.) forms a chemical bond or molecular entanglement with the subsequently coated chlorinated polypropylene and the main resin of the coating, significantly improving the bonding strength of the inorganic-organic interface. Chlorinated polypropylene, as an organic protective layer and compatibilizer, contains chlorine atoms in its molecular chain and exhibits good compatibility with chlorinated polypropylene, SBS, and oil-based acrylic resin in the main coating formulation. After spraying, it forms an extremely thin organic film on the Ag-Al surface, which adheres firmly after drying, improving the coating's wear resistance and corrosion resistance.

[0017] The Ag-Al composite filler, formed by mixing multiple components, exhibits a multi-layered structure consisting of an aluminum core, a silver layer, a silane coupling agent monolayer, and a chlorinated polypropylene thin layer. This structure achieves a gradient transition in conductivity, interfacial bonding, and resin compatibility from the inside out, forming a molecular-level match with the main coating formulation and enhancing the overall performance of the coating.

[0018] Preferably, the magnetron sputtering has the following characteristics: sputtering power: 100-120W, sputtering gas pressure: 0.5-0.6Pa, sputtering bias voltage: -20-60V, and sputtering time: 15-25min.

[0019] By adopting the above technical solution and setting various magnetron sputtering parameters, these parameters together determine the deposition rate, density, uniformity, and bonding strength of the silver layer with the aluminum powder matrix. These parameters are then integrated into a complete Ag-Al composite filler preparation method to obtain a highly conductive filler that is completely compatible with the matrix resin.

[0020] Preferably, the target material is high-purity silver, and the thickness of the silver plating layer is 50-60 nm.

[0021] By adopting the above technical solution, setting the sputtering gas pressure, balancing density and coating properties, avoiding excessive power density that leads to coarse grains, enhancing bonding force, cleaning the surface, ensuring sufficient conductivity with the thickness of the silver plating layer, and keeping costs under control.

[0022] Preferably, the graphene is obtained by treatment with maleic anhydride graft copolymer.

[0023] By employing the above technical solution, ethanol is used as the dispersion medium to uniformly disperse graphene into a suspension. Chlorinated polypropylene grafted with maleic anhydride (CPP-g-MAH) is then added. The chlorinated polypropylene backbone is completely compatible with the coating matrix, while SBS and acrylic resin exhibit good compatibility with chlorinated polypropylene. After coating, the graphene surface transforms from an inorganic / carbon material into a chlorinated polypropylene layer, forming molecular chain entanglement with the coating resin, resulting in good dispersibility. The maleic anhydride graft groups undergo ring-opening esterification or amidation reactions with the hydroxyl and carboxyl groups and other oxygen-containing functional groups on the graphene surface, forming covalent bonds. This allows CPP-g-MAH to firmly adhere to the graphene surface, making it difficult to desorb. Graphene maintains its complete two-dimensional sheet structure, and its conductivity remains unaffected. CPP-g-MAH is firmly anchored by chemical bonds, and the outer layer, chlorinated polypropylene, forms molecular-level compatibility with the coating resin. The high conductivity of graphene is fully preserved, forming a conductive filler group with Ag-Al / CNTs filler that is chemically consistent with the surface. This is beneficial for building a stable and efficient conductive network, while also improving the wear resistance, mechanical properties, and corrosion resistance of the coating.

[0024] Preferably, the defoamer is a polysiloxane-based defoamer.

[0025] By adopting the above technical solution, polysiloxane has extremely low surface tension and excellent spreadability in oily systems, which can effectively break up macroscopic bubbles entangled in mechanical stirring and microbubbles generated during coating application, and its compatibility with resin systems is controllable.

[0026] Secondly, this application also provides a method for preparing a conductive oil-based coating, comprising the following steps: (1) Mix polypyrrole with high molecular weight dispersant BYK-2150 and xylene, and disperse at high speed to form a uniform suspension to obtain mixture one, which is ready for use; (2) Dissolve styrene-butadiene-styrene block copolymer and chlorinated polypropylene in xylene and cyclohexanone, stir until completely dissolved, add oily acrylic resin, stir evenly to obtain mixture II; (3) While stirring, add mixture one, graphene, Ag-Al composite filler, hydrophobic titanium dioxide, fumed silica and polymeric dispersant BYK-2150 to mixture two in sequence, disperse, and obtain mixture three; (4) Add n-butanol, antioxidant and defoamer to the mixture, stir for 10-15 minutes, let stand and mature for 4-8 hours to obtain the final product.

[0027] By adopting the above technical solution, graphene is first dispersed and directly added, eliminating the need for high-intensity pre-dispersion; polypyrrole is pre-dispersed separately and then added to avoid cross-contamination; fumed silica is fully activated during the high-speed dispersion stage, synergistically forming suitable thixotropy with the subsequently added n-butanol, balancing anti-settling and construction leveling. The defoamer is added last to avoid high-shear emulsification; after curing, all bubbles escape completely, resulting in a coating free of pinhole defects.

[0028] Preferably, in step (1), the fineness of the mixture is ≤5μm, and in step (3), the fineness of the mixture is ≤20μm.

[0029] By adopting the above technical solutions, in step (1), the fineness of the mixture is ≤5 μm. Considering the high specific surface area and easy agglomeration of graphene, high-intensity pre-dispersion is used to ensure that it is uniformly dispersed in a single layer or a small number of layers, which is the basis for constructing a high-efficiency conductive network. In step (3), the fineness of the mixture is ≤20 μm. Considering the comprehensive dispersion requirements of the entire filler system (including micron-sized Ag-Al / CNTs, nano-sized polypyrrole, hydrophobic titanium dioxide, and fumed silica), it is ensured that there are no large particles remaining in the final coating, thus ensuring the appearance and conductivity uniformity of the coating.

[0030] In summary, this application has the following beneficial effects: 1. In this application, the chlorine atoms in the chlorinated polypropylene molecular chain have a good affinity with oily acrylic resin, and are also compatible with styrene-butadiene-styrene block copolymer, effectively preventing phase separation, improving coating uniformity and adhesion, and enhancing the coating's water resistance, abrasion resistance, and peel resistance.

[0031] 2. The various components of the coating in this application are formulated using SBS and acrylic resin. The polarity difference is resolved by chlorinated polypropylene to achieve a balance between flexibility and hardness. A three-dimensional multi-scale conductive network of graphene, Ag-Al, and polypyrrole is constructed, taking into account conductivity efficiency, mechanical properties, and filler cost.

[0032] 3. The mixed solvent in this application takes into account the solubility, volatility gradient and application adaptability of each resin, ensuring good wet film leveling, no defects in dry film, and guaranteeing the wear resistance, corrosion resistance and durability of the coating. Detailed Implementation

[0033] The present application will be further described in detail below with reference to the embodiments.

[0034] The raw materials used in the examples and comparative examples are all commercially available.

[0035] Preparation Example 1: The Ag-Al composite filler consists of aluminum powder, silane coupling agent, and chlorinated polypropylene. The aluminum powder is silver-plated on the surface by magnetron sputtering.

[0036] Specifically, the preparation methods of Ag-Al composite fillers include the following: 10g of aluminum powder (purchased from Hunan Jinhao New Material Technology Co., Ltd., high-purity flake aluminum powder) was placed on the sample tray of a magnetron sputtering instrument and silvered by magnetron sputtering. Then, it was dispersed into 50mL of 0.5% KH560 ethanol solution of silane coupling agent, the pH was adjusted to 5, stirred for 35min, filtered, dried, and then sprayed with 2mL of 10% chlorinated polypropylene / xylene solution. After drying and dispersing, Ag-Al composite filler was obtained. The process was repeated to obtain the required amount of Ag-Al composite filler.

[0037] Magnetron sputtering: Argon gas was introduced at 20 sccm, sputtering power was 120 W, sputtering pressure was 0.6 Pa, sputtering bias was 60 V, and sputtering time was 25 min.

[0038] Target material: High-purity silver (purity ≥99.99%), silver plating thickness: 50-60 nm. Equipment type: Rotary powder sputtering system.

[0039] Preparation Example 2: The difference from Preparation Example 1 lies in the preparation method of the Ag-Al composite filler, which includes the following: 10g of aluminum powder was placed on the sample tray of a magnetron sputtering instrument and silvered by magnetron sputtering. Then it was dispersed into 50mL of 0.5% KH560 ethanol solution of silane coupling agent, the pH was adjusted to 4, stirred for 30min, filtered, dried, and then sprayed with 2mL of 10% chlorinated polypropylene / xylene solution. After drying and dispersing, Ag-Al composite filler was obtained.

[0040] Magnetron sputtering: Argon gas was introduced at 20 sccm, sputtering power was 100 W, sputtering pressure was 0.5 Pa, sputtering bias was -20 V, and sputtering time was 15 min.

[0041] Target material: High-purity silver (purity ≥99.99%), silver plating thickness: 50-60 nm. Equipment type: Rotary powder sputtering system.

[0042] Preparation Example 3: The difference from Preparation Example 1 lies in the preparation method of the Ag-Al composite filler, which includes the following: 10g of aluminum powder was placed on the sample tray of a magnetron sputtering instrument and silvered on the surface by magnetron sputtering. Then, 2mL of 10% chlorinated polypropylene / xylene solution was sprayed on the powder, dried, and dispersed to obtain Ag-Al composite filler.

[0043] Preparation Example 4: The difference from Preparation Example 1 lies in the preparation method of the Ag-Al composite filler, which includes the following: 10g of aluminum powder was placed on the sample tray of a magnetron sputtering instrument and silvered on the surface by magnetron sputtering. Then it was dispersed into 50mL of 0.5% KH560 ethanol solution of silane coupling agent, the pH was adjusted to 5, stirred for 35min, filtered, dried and dispersed to obtain Ag-Al composite filler.

[0044] Preparation Example 5: Graphene was obtained by grafting maleic anhydride onto a copolymer.

[0045] Specifically, the graphene pretreatment is as follows: 20g of graphene was dispersed in 200mL of ethanol, and 3g of chlorinated polypropylene grafted maleic anhydride (purchased from Dongguan Shenghao Plastic Raw Materials Co., Ltd.) was added. The mixture was stirred for 30min, dried, and dispersed to obtain pretreated graphene. The process was repeated to obtain the required amount of graphene.

[0046] Preparation Example 6: The difference from Preparation Example 5 lies in the graphene pretreatment, as follows: 20g of graphene was dispersed in 200mL of ethanol, 3g of chlorinated polypropylene grafted with maleic anhydride was added, stirred for 35min, dried, and dispersed to obtain pretreated graphene.

[0047] Preparation Example 7: The difference from Preparation Example 5 lies in the graphene pretreatment, as follows: 20g of graphene was dispersed in 200mL of ethanol, stirred for 35min, dried, and dispersed to obtain pretreated graphene.

[0048] Example 1: A conductive oil-based coating, by weight, comprises the following raw materials: 12 kg of styrene-butadiene-styrene block copolymer, 45 kg of oil-based acrylic resin (purchased from Shandong Jibei New Materials Co., Ltd.), 4 kg of chlorinated polypropylene (purchased from Hubei Xinghengye Technology Co., Ltd.), 10 kg of conductive filler, 5 kg of hydrophobic titanium dioxide R706, 0.3 kg of defoamer (polysiloxane BYK-066N), 20 kg of n-butanol, 30 kg of xylene, 0.5 kg of antioxidant 1010, and 10 kg of cyclohexanone; The conductive fillers include graphene, Ag-Al composite filler, polypyrrole (purchased from Hubei Yunmei Technology Co., Ltd.), 0.3 kg of polymeric dispersant BYK-2150, and 0.6 kg of fumed silica.

[0049] The mass ratio of graphene, Ag-Al composite filler, and polypyrrole is 1:2:1.2.

[0050] The above-mentioned method for preparing a conductive oil-based coating includes the following steps: (1) Mix polypyrrole with 0.2 kg of high molecular weight dispersant BYK-2150 and 10 kg of xylene, and disperse at high speed (1500 rpm, 15 min) until a uniform suspension is obtained to obtain mixture one, which is ready for use; (2) Dissolve the styrene-butadiene-styrene block copolymer and chlorinated polypropylene in the remaining xylene and cyclohexanone, stir until completely dissolved (500 rpm, 30 min), add oily acrylic resin, stir evenly to obtain mixture II; (3) Add mixture one, graphene, Ag-Al composite filler, hydrophobic titanium dioxide, fumed silica and remaining dispersant BYK-2150 to mixture two in sequence under stirring, and disperse (2000 rpm, 30 min) to obtain mixture three; (4) Add n-butanol, antioxidant 1010 and defoamer BYK-066N to the mixture, stir (800 rpm, 10 min), and let stand for 4 hours to mature.

[0051] In step (1), the fineness of the mixture is ≤5μm, and in step (3), the fineness of the mixture is ≤20μm.

[0052] The Ag-Al composite filler was prepared using Preparation Example 1.

[0053] Example 2: A conductive oil-based coating, differing from Example 1 in that, by weight, it comprises the following raw materials: 15 kg of styrene-butadiene-styrene block copolymer, 50 kg of oil-based acrylic resin, 6 kg of chlorinated polypropylene, 15 kg of conductive filler, 3 kg of hydrophobic titanium dioxide R706, 0.5 kg of defoamer (polysiloxane BYK-066N), 15 kg of n-butanol, 40 kg of xylene, 1.0 kg of antioxidant 1010, and 15 kg of cyclohexanone; The conductive filler includes graphene, Ag-Al composite filler, polypyrrole, 0.3 kg of polymeric dispersant BYK-2150, and 0.8 kg of fumed silica.

[0054] The mass ratio of graphene, Ag-Al composite filler, and polypyrrole is 1:3:0.8.

[0055] The above-mentioned method for preparing a conductive oil-based coating includes the following steps: (1) Mix polypyrrole with 0.2 kg of high molecular weight dispersant BYK-2150 and 10 kg of xylene, and disperse at high speed to form a uniform suspension to obtain mixture one, which is ready for use; (2) Dissolve the styrene-butadiene-styrene block copolymer and chlorinated polypropylene in the remaining xylene and cyclohexanone, stir until completely dissolved, add oily acrylic resin, stir evenly, and obtain mixture II; (3) While stirring, add mixture one, graphene, Ag-Al composite filler, hydrophobic titanium dioxide, fumed silica and the remaining dispersant BYK-2150 to mixture two in sequence, disperse, and obtain mixture three; (4) Add n-butanol, antioxidant 1010 and defoamer BYK-066N to the mixture, stir, and let stand for 8 hours to mature.

[0056] Example 3: A conductive oil-based coating, which differs from Example 1 in that the mass ratio of graphene, Ag-Al composite filler, and polypyrrole is 1:1:2.5.

[0057] Example 4: A conductive oil-based coating, which differs from Example 1 in that the Ag-Al composite filler is prepared using Preparation Example 2.

[0058] Example 5: A conductive oil-based coating, which differs from Example 1 in that the Ag-Al composite filler is prepared using Preparation Example 3.

[0059] Example 6: A conductive oil-based coating, which differs from Example 1 in that the Ag-Al composite filler was prepared using Preparation Example 4.

[0060] Example 7: A conductive oil-based coating, which differs from Example 1 in that the graphene pretreatment was prepared using Preparation Example 5.

[0061] Example 8: A conductive oil-based coating, which differs from Example 1 in that the graphene pretreatment was prepared using Preparation Example 6.

[0062] Example 9: A conductive oil-based coating, which differs from Example 1 in that the graphene pretreatment was prepared using Preparation Example 7.

[0063] Comparative Example 1: A conductive oil-based coating, which differs from Example 1 in that it does not contain graphene.

[0064] Comparative Example 2: A conductive oil-based coating differs from Example 1 in that it does not contain Ag-Al composite filler.

[0065] Comparative Example 3: A conductive oil-based coating, which differs from Example 1 in that it does not contain polypyrrole.

[0066] Performance testing was conducted on a conductive oil-based coating prepared in Examples 1-9 and Comparative Examples 1-3. The adhesion of the prepared conductive oil-based coating was tested according to ASTM D3359-1997 "Paint Adhesion Test"; the coating sample was prepared using PP substrate, and the coating thickness was 20 μm after UV curing.

[0067] The conductive oil-based coating was tested for abrasion resistance using an RCA abrasion tester conforming to ASTM F2357-04. The test sample was tested for the number of times it could withstand RCA paper tape. Coating samples were prepared using PP substrate boards, and the coating thickness was 20 μm after UV curing.

[0068] The prepared conductive oil-based coating was subjected to salt spray resistance test according to GB / T1771-1991 "Determination of resistance to neutral salt spray of paints and varnishes" to evaluate the coating's resistance to salt spray corrosion; the test results are shown in Table 1.

[0069] Table 1 Test data for the examples and comparative examples

[0070] As shown in Table 1, the conductive oil-based coatings prepared in Examples 1-2 and 4 of this application exhibit good mechanical properties, abrasion resistance, and corrosion resistance. Specifically, Example 1 shows an adhesion strength of 5B, an RCA abrasion cycle of 650 cycles, and a salt spray resistance of 120 hours without blistering or corrosion. Therefore, the conductive oil-based coatings prepared in this application effectively prevent phase separation through the synergistic combination of multiple components, improving coating uniformity and adhesion, and enhancing the coating's salt spray resistance, abrasion resistance, and peel resistance.

[0071] A conductive oil-based coating sample prepared in Example 1 was fabricated using a PP (polycarbonate) substrate plate. After UV curing, the surface resistivity and resistance of the coating were measured using a four-probe tester. Multiple measurements were taken, and the average value was calculated. The resistivity was 5.98 × 10⁻⁶. 1 Ω·cm, surface resistivity is 5.22×10 2 Ω / sq.

[0072] According to GB / T6739-2006 "Determination of Hardness of Coatings by Pencil Test", the hardness of the prepared conductive oil-based coating was tested. The coating sample was prepared using a PP substrate. After UV curing, the coating thickness was 20 μm. A 1H pencil was used and a weight of 1 kg was applied to the hardness tester. The pencil was used to plow the coating. A continuous scratch of ≥3 mm was considered a break. Conclusion: No plastic deformation or cohesive failure was observed on the surface of the coating sample.

[0073] Example 3 changed the mass ratio of graphene, Ag-Al composite filler, and polypyrrole. As can be seen from Table 1, the test results of RCA friction cycles and salt spray resistance of Example 3 were significantly worse than those of Examples 1-2. This indicates that the three-component mixture constructs a three-dimensional conductive network with a micron-scale skeleton (Ag-Al), submicron filler (polypyrrole), and nano-bridge (graphene), achieving high conductivity and isotropy with low filler content. Polypyrrole and graphene synergistically inhibit the precipitation and corrosion of Ag-Al, and improve the mechanical stability, wear resistance, and environmental durability of the conductive network.

[0074] In Examples 5-6, no silane coupling agent or chlorinated polypropylene was added to the Ag-Al composite filler. As can be seen from Table 1, the test results of RCA friction cycles and salt spray resistance in Examples 5-6 were significantly worse than those in Examples 1-2. This indicates that the Ag-Al composite filler formed by multi-component mixing exhibits a multi-layer structure of aluminum core, silver layer, silane coupling agent monolayer, and chlorinated polypropylene thin layer. It achieves a gradient transition in conductivity, interfacial bonding force, and resin compatibility from the inside out, forming good durability, abrasion resistance, and longevity with the main coating formulation.

[0075] Examples 7-8 pretreated graphene. As shown in Table 1, the RCA abrasion cycles and salt spray resistance of Examples 7-8 were significantly better than those of Examples 1-2. This indicates that the graphene maintains a complete two-dimensional sheet structure, its conductivity is not affected, and the CPP-g-MAH is firmly anchored by chemical bonds. The outer layer is chlorinated polypropylene, which forms good compatibility with the coating resin, thereby improving the overall performance of the coating and resulting in a coating with excellent durability.

[0076] In Example 9, the graphene pretreatment was simply dispersed with ethanol. As can be seen from Table 1, the test results of RCA friction cycles and salt spray resistance in Example 9 were slightly better than those in Examples 1-2, indicating that the use of ethanol pretreatment alone had little impact on the performance improvement of the subsequent coating.

[0077] Comparative Examples 1-3 were prepared without graphene, Ag-Al composite filler, and polypyrrole, respectively. Table 1 shows that the adhesion, RCA abrasion cycles, and salt spray resistance of Comparative Examples 1-3 were significantly worse than those of Examples 1-2. This indicates that graphene possesses extremely high specific surface area and conductivity, constructing a highly efficient conductive network that significantly improves conductivity and enhances coating strength, wear resistance, thermal conductivity, and dimensional stability. The Ag-Al composite filler provides conductive pathways, reduces surface resistivity, and synergizes with graphene to achieve high conductivity pathways, improving wear resistance and corrosion resistance. Polypyrrole, a conductive polymer, supplements conductive pathways, improves conductivity uniformity, fills the gaps between graphene sheets and Ag-Al particles, enhances the density and isotropy of the conductive network, improves the dispersion of inorganic conductive fillers, reduces agglomeration, and improves coating stability, wear resistance, and corrosion resistance.

[0078] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A conductive oil-based coating, characterized in that, By weight, it comprises the following raw materials: 12-15 parts of styrene-butadiene-styrene block copolymer, 45-50 parts of oily acrylic resin, 4-6 parts of chlorinated polypropylene, 10-15 parts of conductive filler, 3-5 parts of hydrophobic titanium dioxide, 0.3-0.5 parts of defoamer, 15-20 parts of n-butanol, 30-40 parts of xylene, 0.5-1.0 parts of antioxidant, and 10-15 parts of cyclohexanone; The conductive fillers include graphene, Ag-Al composite filler, polypyrrole, high molecular weight dispersant BYK-2150, and fumed silica.

2. The conductive oil-based coating according to claim 1, characterized in that, The mass ratio of graphene, Ag-Al composite filler, and polypyrrole is 1:2-3:0.8-1.

2.

3. The conductive oil-based coating according to claim 1, characterized in that, The Ag-Al composite filler is composed of aluminum powder, silane coupling agent, and chlorinated polypropylene. The aluminum powder is silver-plated on the surface by magnetron sputtering.

4. The conductive oil-based coating according to claim 3, characterized in that, Magnetron sputtering: sputtering power: 100-120W, sputtering gas pressure: 0.5-0.6Pa, sputtering bias voltage: -20-60V, sputtering time: 15-25min.

5. A conductive oil-based coating according to claim 3, characterized in that, Target material: high-purity silver, with a silver plating thickness of 50-60 nm.

6. The conductive oil-based coating according to claim 1, characterized in that, The graphene was obtained by treating it with maleic anhydride graft copolymer.

7. The conductive oil-based coating according to claim 1, characterized in that, The defoamer is a polysiloxane-based defoamer.

8. The method for preparing a conductive oil-based coating according to claim 1, characterized in that, Includes the following steps: (1) Mix polypyrrole with high molecular weight dispersant BYK-2150 and xylene, and disperse at high speed to form a uniform suspension to obtain mixture one, which is ready for use; (2) Dissolve styrene-butadiene-styrene block copolymer and chlorinated polypropylene in xylene and cyclohexanone, stir until completely dissolved, add oily acrylic resin, stir evenly to obtain mixture II; (3) While stirring, add mixture one, graphene, Ag-Al composite filler, hydrophobic titanium dioxide, fumed silica and polymeric dispersant BYK-2150 to mixture two in sequence, disperse, and obtain mixture three; (4) Add n-butanol, antioxidant and defoamer to the mixture, stir for 10-15 minutes, let stand and mature for 4-8 hours to obtain the final product.

9. The method for preparing a conductive oil-based coating according to claim 8, characterized in that, In step (1), the fineness of the mixture is ≤5μm, and in step (3), the fineness of the mixture is ≤20μm.

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