Conductive carbon oil and preparation method thereof

Abstract

The invention discloses conductive carbon oil and a preparation method thereof, and relates to the technical field of conductive carbon oil. The conductive carbon oil is prepared from the following raw materials in percentage by weight: 16 to 20 percent of graphene / carbon nanotube composite material, 25 to 35 percent of epoxy resin modified UV (Ultraviolet) cured polyurethane, 2 to 8 percent of reactive diluent, 10 to 16 percent of carbon powder, 2 to 4 percent of photoinitiator, 2 to 4 percent of synergist and 25 to 40 percent of diluent water. Under the comprehensive synergistic effect of the graphene / carbon nanotube composite material, the epoxy resin modified UV cured polyurethane, the reactive diluent, the synergist and other component raw materials, the conductive carbon oil with high conductivity and stable conductivity is comprehensively prepared, and the conductive carbon oil has good adhesiveness and toughness after being cured.

Description

Technical Field

[0001] The present invention relates to the technical field of conductive carbon oil, and specifically to a conductive carbon oil and a preparation method thereof. Background Art

[0002] In recent years, with the rapid development of flexible electronics, printed circuits, and wearable devices, conductive carbon oil, as a key functional material, has received extensive attention due to its low cost, printability, and environmental friendliness. Traditional conductive inks mostly rely on precious metal powders such as silver and copper as conductive fillers. Although they have excellent electrical conductivity, the high raw material cost and metal oxidation problems limit their large-scale application. Carbon-based materials (such as carbon black, graphene, and carbon nanotubes) have become ideal alternatives to metals due to their high electrical conductivity, chemical stability, and light weight. However, single carbon materials have problems such as low efficiency in constructing conductive networks, poor filler dispersion, and weak interfacial bonding with matrix resins, resulting in high coating resistivity and insufficient mechanical properties, making it difficult to meet the requirements of high-precision printed circuits or dynamic flexible scenarios.

[0003] On the other hand, the resin selection in conductive carbon oil also directly affects the adhesion and durability of the conductive coating. Traditional pure polyurethane has good flexibility but insufficient polarity, making it difficult to form a stable interface with carbon fillers; while epoxy resin has high hardness but high brittleness after curing.

[0004] In summary, to solve the above problems, the present invention will provide a conductive carbon oil and a preparation method thereof, which is of great significance. Summary of the Invention

[0005] The purpose of the present invention is to provide a conductive carbon oil and a preparation method thereof to solve the problems raised in the above background art.

[0006] To solve the above technical problems, the present invention provides the following technical solutions:

[0007] A conductive carbon oil, comprising the following component raw materials: by weight percentage, 16 - 20% of graphene / carbon nanotube composite, 25 - 35% of epoxy resin modified UV curable polyurethane, 2 - 8% of reactive diluent, 10 - 16% of carbon powder, 2 - 4% of photoinitiator, 2 - 4% of synergist, and 25 - 40% of thinner.

[0008] Further, the preparation method of the graphene / carbon nanotube composite is as follows:

[0009] (1) First, disperse graphene oxide in deionized water to obtain a graphene oxide dispersion with a concentration of 10 - 20 mg / mL. Then, transfer the graphene oxide dispersion to a high-pressure reactor, and further add silver nitrate and ascorbic acid thereto. After ultrasonic dispersion until uniform, react at 130 - 160 °C for 12 - 24 h to end the reaction. Finally, freeze the reaction product into blocks and freeze-dry it to obtain a silver / graphene composite material;

[0010] (2) Disperse a titanate coupling agent in an ethanol aqueous solution of 75 wt%, and stir and mix for 30 - 60 min to obtain a titanate coupling agent hydrolysis solution with a concentration of 2 - 6 wt%;

[0011] (3) Add the silver / graphene composite material and carbon nanotubes to the titanate coupling agent hydrolysis solution, stir and mix for 20 - 60 min, filter, and dry to obtain a graphene / carbon nanotube composite material.

[0012] Further, the mass ratio of the graphene oxide, silver nitrate, and ascorbic acid is 10:(1 - 2):(0.5 - 1).

[0013] Further, the mass ratio of the silver / graphene composite material, carbon nanotubes, and the titanate coupling agent hydrolysis solution is 2:(1 - 3):1.

[0014] Further, the preparation method of the epoxy resin-modified UV-curable polyurethane is as follows:

[0015] (1) Add epoxy resin to a reaction vessel and heat up to 80 - 90 °C. Then, under nitrogen protection, slowly dropwise add a mixed solution of acrylic acid, p-methoxyphenol, and triphenylphosphine into the vessel while stirring. After the dropwise addition is completed, heat up to 110 ± 2 °C and continue to react for 2 - 6 h to end the reaction, obtaining an acrylic acid-modified epoxy resin;

[0016] (2) Add a diol, a diisocyanate, dibutyltin dilaurate, and acetone to a reaction vessel, stir and heat up to 70 - 85 °C under nitrogen protection for a prepolymerization reaction for 2 - 6 h. Then, add the acrylic acid-modified epoxy resin to the reaction system, stir and react until the isocyanate group content is constant, and after separation and purification, obtain an epoxy resin-modified UV-curable polyurethane.

[0017] Further, the mass ratio of the epoxy resin, acrylic acid, p-methoxyphenol, and triphenylphosphine is 1:(0.38 - 0.42):(0.005 - 0.01):(0.005 - 0.01).

[0018] Further, the model of the epoxy resin is CELLOXIDE 2081, and its epoxy equivalent is 200 g / eq.

[0019] Further, the mass ratio of the diol, diisocyanate, acrylic acid-modified epoxy resin, and dibutyltin dilaurate is 1:(0.8 - 1):(0.3 - 0.5):(0.03 - 0.05).

[0020] Further, the diol includes, but is not limited to, one or a combination of several of polyethylene glycol, polycarbonate diol, polycaprolactone diol, and polytetrahydrofuran ether diol.

[0021] Further, the diisocyanate includes, but is not limited to, one or a combination of several of toluene diisocyanate, isophorone diisocyanate, 4,4'-diphenylmethane diisocyanate, and hexamethylene diisocyanate.

[0022] Further, the reactive diluent includes, but is not limited to, one or a combination of several of isodecyl acrylate, 1,6-hexanediol diacrylate, and pentaerythritol tetraacrylate.

[0023] Further, the photoinitiator is photoinitiator 1173.

[0024] Further, the synergist is BYK-163.

[0025] Further, the thinner is obtained by mixing toluene, xylene, and acetone in a mass ratio of 1:1:3; this thinner can disperse each raw material well, making the conductive carbon oil have good rheological properties and coating film-forming properties.

[0026] A preparation method of a conductive carbon oil, specifically: uniformly mixing a graphene / carbon nanotube composite material, an epoxy resin-modified UV-curable polyurethane, a reactive diluent, carbon powder, a photoinitiator, a synergist, and a thinner to obtain the conductive carbon oil.

[0027] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0028] 1. In the present invention, graphene oxide and silver nitrate are first subjected to a hydrothermal reaction at high temperature, and ascorbic acid is added simultaneously to assist in the reduction reactions of both graphene oxide and silver ions. Among them, the silver ions are reduced to silver nanoparticles, which are uniformly adsorbed on the surface of reduced graphene oxide through electrostatic adsorption. The silver / graphene composite material is prepared. In this silver / graphene composite material, due to the control of ascorbic acid in the scheme, some oxygen-containing groups will remain in the reduced graphene oxide, which will enhance the bonding strength between the silver nanoparticles and the reduced graphene oxide. Finally, under the bridging action of titanate coupling agent, carbon nanotubes and the silver / graphene composite material are firmly bonded together to prepare the graphene / carbon nanotube composite material. The graphene / carbon nanotube composite material has a multi-level conductive network, so its electrical conductivity is relatively excellent. Secondly, the introduction of carbon nanotubes also endows the graphene / carbon nanotube composite material with certain mechanical flexibility, making it more suitable for application in conductive carbon oil for coating, which can effectively enhance the toughness of the coating. That is, the graphene / carbon nanotube composite material can significantly enhance the electrical conductivity of the conductive carbon oil and the toughness of the cured conductive coating.

[0029] 2. In the present invention, acrylic acid is used to modify epoxy resin, and then it is used as a chain extender to react with diol and diisocyanate to obtain epoxy resin-modified UV-curable polyurethane. The epoxy resin-modified UV-curable polyurethane combines flexible segments and rigid segments, greatly integrating the advantages of both, and can endow the conductive coating with good mechanical properties. In addition, since the epoxy resin-modified UV-curable polyurethane contains polar bonds and unsaturated bonds, the polar bonds can play an adsorption role on the functional groups on the surface of the graphene / carbon nanotube composite material and carbon powder, thereby reducing the agglomeration and sedimentation of the two in the conductive carbon oil; the unsaturated bonds can form a crosslinked network after UV curing, playing a role in restricting the migration of the graphene / carbon nanotube composite material and carbon powder. That is, the conductive carbon oil has excellent and stable electrical conductivity. In addition, the introduction of the epoxy resin segment can also enhance the bonding force between the conductive carbon oil and the coated substrate, enhancing the adhesion of the conductive carbon oil.

[0030] 3. In the present invention, an active diluent is further added, which can enhance the UV curing crosslinking density, reduce the volume shrinkage after curing, and contribute to obtaining a conductive coating with high electrical conductivity and toughness.

[0031] 4. In the present invention, BYK-163 is added as a synergist, which can play a wetting and dispersing role, further promote the dispersion of the graphene / carbon nanotube composite material and carbon powder, thereby avoiding their agglomeration and preventing their sedimentation, effectively enhancing the electrical conductivity and electrical stability of the conductive carbon oil.

[0032] In summary, under the comprehensive synergistic effect of component raw materials such as graphene / carbon nanotube composites, epoxy resin-modified UV-curable polyurethane, reactive diluents, and synergists, a highly conductive and stable conductive carbon oil is comprehensively prepared, which has good adhesion and toughness after curing. Detailed implementation manners

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] It should be noted that the following parts are by weight, and there are no special restrictions on the purchasing manufacturers of all the raw materials involved in the present invention. Exemplarily, they include:

[0035] In the following examples, graphene oxide, monolayer, with a sheet diameter of 0.2 - 2 μm, and graphene, monolayer, with a sheet diameter of 0.2 - 2 μm, are both purchased from Shanghai Lianghan Nano Technology Development Co., Ltd.;

[0036] Epoxy resin, with the model CELLOXIDE 2081 and an epoxy equivalent of 200 g / eq, is purchased from Guangzhou Yihuisheng Chemical Co., Ltd.;

[0037] Carbon powder, with a particle size of 5 - 10 μm, isopropyltri(isostearoyl)titanate with a purity of 99%, ascorbic acid with a purity of 99%, silver nitrate with a purity of 99%, carbon nanotubes, with a diameter of 2 - 10 nm and a length of 0.5 - 2 μm, 1,6-hexanediol diacrylate with a purity of 98%, CAS No.: 13048-33-4, isophorone diisocyanate with a purity of 98%, polycaprolactone diol with a purity of 98% and a molecular weight of 2000, photoinitiator 1173, and BYK-163 are all purchased from Merck & Co., Inc.; the remaining raw materials are all commercially available.

[0038] Example 1: A preparation method of conductive carbon oil:

[0039] Step 1: 1. Prepare graphene / carbon nanotube composite: (1) First, disperse graphene oxide in deionized water to obtain a graphene oxide dispersion with a concentration of 15 mg / mL. Then transfer the graphene oxide dispersion to a high-pressure reactor, and continue to add silver nitrate and ascorbic acid thereto. After ultrasonic dispersion until homogeneous, react at 150 °C for 24 h to end the reaction. Finally, the reaction product is frozen into blocks and freeze-dried to obtain silver / graphene composite. Among them, the mass ratio of graphene oxide, silver nitrate, and ascorbic acid is 10:1.5:0.75. (2) Disperse isopropyltri(isostearoyl) titanate in an ethanol aqueous solution with a mass fraction of 75%, and stir and mix for 45 min to obtain a 4 wt% isopropyltri(isostearoyl) titanate hydrolysis solution. (3) Add the silver / graphene composite and carbon nanotubes to the isopropyltri(isostearoyl) titanate hydrolysis solution, stir and mix for 40 min, and then filter and dry to obtain the graphene / carbon nanotube composite. Among them, the mass ratio of the silver / graphene composite, carbon nanotubes, and titanate coupling agent hydrolysis solution is 2:2:1.

[0040] 2. Prepare epoxy resin-modified UV-curable polyurethane: (1) Add CELLOXIDE 2081 type epoxy resin to a reaction vessel and heat up to 85 °C. Then, under nitrogen protection, slowly dropwise add a mixed solution of acrylic acid, p-methoxyphenol, and triphenylphosphine into the vessel while stirring. After the addition is completed, heat up to 110 ± 2 °C and continue to react for 4 h to end the reaction, obtaining acrylic acid-modified epoxy resin. Among them, the mass ratio of epoxy resin, acrylic acid, p-methoxyphenol, and triphenylphosphine is 1:0.4:0.0075:0.0075. (2) Add polycaprolactone diol, isophorone diisocyanate, dibutyltin dilaurate, and an appropriate amount of acetone to a reaction vessel. Under nitrogen protection, stir and heat up to 80 °C for a prepolymerization reaction for 4 h. Then add the acrylic acid-modified epoxy resin to the reaction system and stir until the isocyanate group content is constant. After separation and purification, obtain the epoxy resin-modified UV-curable polyurethane. Among them, the mass ratio of polycaprolactone diol, isophorone diisocyanate, acrylic acid-modified epoxy resin, and dibutyltin dilaurate is 1:0.9:0.4:0.04.

[0041] 3. Prepare thinner: Mix toluene, xylene, and acetone in a mass ratio of 1:1:3 to obtain the thinner.

[0042] Step 2: Mix the graphene / carbon nanotube composite, epoxy resin-modified UV-curable polyurethane, 1,6-hexanediol diacrylate, carbon powder, photoinitiator 1173, BYK-163, and thinner evenly to obtain the conductive carbon oil.

[0043] Among them, the raw materials of each component of the conductive carbon oil: by weight percentage, 18% of graphene / carbon nanotube composite, 30% of epoxy resin modified UV curable polyurethane, 5% of 1,6-hexanediol diacrylate, 13% of carbon powder, 3% of photoinitiator 1173, 3% of BYK-163, and 28% of thinner.

[0044] Example 2: A preparation method of conductive carbon oil:

[0045] Step 1: 1. Prepare graphene / carbon nanotube composite: (1) First, disperse graphene oxide into deionized water to obtain a graphene oxide dispersion with a concentration of 15 mg / mL; then transfer the graphene oxide dispersion to a high-pressure reaction kettle, and continue to add silver nitrate and ascorbic acid thereto, ultrasonically disperse evenly, and then react at 150 °C for 24 h to end the reaction; finally, the reaction product is frozen into blocks and freeze-dried to obtain silver / graphene composite; among them, the mass ratio of graphene oxide, silver nitrate, and ascorbic acid is 10:1:0.5; (2) Disperse isopropyltri(isostearoyl) titanate into an ethanol aqueous solution with a concentration of 75 wt%, stir and mix for 45 min to obtain a 2 wt% isopropyltri(isostearoyl) titanate hydrolysis solution; (3) Add the silver / graphene composite and carbon nanotubes to the isopropyltri(isostearoyl) titanate hydrolysis solution, stir and mix for 40 min, filter and dry to obtain graphene / carbon nanotube composite; among them, the mass ratio of silver / graphene composite, carbon nanotubes, and titanate coupling agent hydrolysis solution is 2:1:1;

[0046] 2. Prepare epoxy resin modified UV curable polyurethane: (1) Add CELLOXIDE 2081 type epoxy resin to a reaction vessel and heat up to 85 °C. Then, under nitrogen protection, slowly dropwise add a mixed solution of acrylic acid, p-methoxyphenol, and triphenylphosphine into the vessel, stir while dropping, and after dropping, heat up to 110 ± 2 °C and continue to react for 4 h to end the reaction to obtain acrylic acid modified epoxy resin; among them, the mass ratio of epoxy resin, acrylic acid, p-methoxyphenol, and triphenylphosphine is 1:0.38:0.005:0.005; (2) Add polycaprolactone diol, isophorone diisocyanate, dibutyltin dilaurate, and an appropriate amount of acetone to a reaction vessel, stir and heat up to 80 °C under nitrogen protection for a prepolymerization reaction for 4 h, then add acrylic acid modified epoxy resin to the reaction system, stir and react until the isocyanate group content is constant, and after separation and purification, obtain epoxy resin modified UV curable polyurethane; among them, the mass ratio of polycaprolactone diol, isophorone diisocyanate, acrylic acid modified epoxy resin, and dibutyltin dilaurate is 1:0.8:0.3:0.03;

[0047] 3. Prepare thinner: Mix toluene, xylene, and acetone in a mass ratio of 1:1:3 to obtain thinner;

[0048] Step 2: Mix the graphene / carbon nanotube composite material, epoxy resin-modified UV-curable polyurethane, 1,6-hexanediol diacrylate, carbon powder, photoinitiator 1173, BYK-163, and thinner evenly to obtain the conductive carbon oil.

[0049] Among them, the raw materials of each component of the conductive carbon oil: by weight percentage, the graphene / carbon nanotube composite material is 18%, the epoxy resin-modified UV-curable polyurethane is 30%, 1,6-hexanediol diacrylate is 5%, the carbon powder is 13%, the photoinitiator 1173 is 3%, BYK-163 is 3%, and the thinner is 28%.

[0050] Example 3: A method for preparing a conductive carbon oil:

[0051] Step 1: 1. Prepare the graphene / carbon nanotube composite material: (1) First, disperse graphene oxide into deionized water to obtain a 15 mg / mL graphene oxide dispersion; then transfer the graphene oxide dispersion to a high-pressure reaction kettle, and continue to add silver nitrate and ascorbic acid thereto, ultrasonically disperse evenly, and then react at 150 °C for 24 h to end the reaction; finally, the reaction product is frozen into blocks and freeze-dried to obtain the silver / graphene composite material; among them, the mass ratio of graphene oxide, silver nitrate, and ascorbic acid is 10:2:1; (2) Disperse isopropyltri(isostearoyl) titanate into a 75 wt% ethanol aqueous solution, stir and mix for 45 min to obtain a 6 wt% isopropyltri(isostearoyl) titanate hydrolysis solution; (3) Add the silver / graphene composite material and carbon nanotubes to the isopropyltri(isostearoyl) titanate hydrolysis solution, stir and mix for 40 min, filter and dry to obtain the graphene / carbon nanotube composite material; among them, the mass ratio of the silver / graphene composite material, carbon nanotubes, and titanate coupling agent hydrolysis solution is 2:3:1;

[0052] 2. Preparation of Epoxy Resin Modified UV-Curable Polyurethane: (1) Add CELLOXIDE 2081 type epoxy resin into a reaction vessel, heat it up to 85 °C, then under nitrogen protection, slowly drip a mixed solution of acrylic acid, p-methoxyphenol, and triphenylphosphine into the vessel, stirring while dripping. After dripping, heat it up to 110 ± 2 °C and continue the reaction for 4 h to end the reaction and obtain acrylic acid modified epoxy resin; among them, the mass ratio of epoxy resin, acrylic acid, p-methoxyphenol, and triphenylphosphine is 1:0.42:0.01:0.01; (2) Add polycaprolactone diol, isophorone diisocyanate, dibutyltin dilaurate, and an appropriate amount of acetone into a reaction vessel, under nitrogen protection, stir and heat up to 80 °C for pre-polymerization reaction for 4 h, then add acrylic acid modified epoxy resin into the reaction system, stir and react until the isocyanate group content is constant, and after separation and purification, obtain epoxy resin modified UV-curable polyurethane; among them, the mass ratio of polycaprolactone diol, isophorone diisocyanate, acrylic acid modified epoxy resin, and dibutyltin dilaurate is 1:1:0.5:0.05;

[0053] 3. Preparation of thinner: Mix toluene, xylene, and acetone in a mass ratio of 1:1:3 to obtain the thinner;

[0054] Step 2: Mix the graphene / carbon nanotube composite material, epoxy resin modified UV-curable polyurethane, 1,6-hexanediol diacrylate, carbon powder, photoinitiator 1173, BYK-163, and the thinner evenly to obtain the conductive carbon oil;

[0055] Among them, the raw materials of each component of the conductive carbon oil: by weight percentage, the graphene / carbon nanotube composite material is 18%, the epoxy resin modified UV-curable polyurethane is 30%, 1,6-hexanediol diacrylate is 5%, the carbon powder is 13%, the photoinitiator 1173 is 3%, BYK-163 is 3%, and the thinner is 28%.

[0056] The following is based on Example 1 for a control experiment, setting Comparative Examples 1-5, specifically as follows:

[0057] Comparative Example 1: Comparative Example 1 is based on Example 1 and adjusted as follows: Graphene is used instead of the graphene / carbon nanotube composite material, and other processes remain unchanged. Specifically as follows:

[0058] A preparation method of conductive carbon oil:

[0059] Step 1: 1. Prepare epoxy resin modified UV curable polyurethane: (1) Add CELLOXIDE 2081 type epoxy resin into a reaction vessel, and heat it up to 85°C. Then, under nitrogen protection, slowly drip a mixed solution of acrylic acid, p-methoxyphenol, and triphenylphosphine into the vessel while stirring. After the dripping is completed, heat it up to 110 ± 2°C and continue the reaction for 4 h to end the reaction and obtain acrylic acid modified epoxy resin. Among them, the mass ratio of epoxy resin, acrylic acid, p-methoxyphenol, and triphenylphosphine is 1:0.4:0.0075:0.0075; (2) Add polycaprolactone diol, isophorone diisocyanate, dibutyltin dilaurate, and an appropriate amount of acetone into a reaction vessel. Under nitrogen protection, stir and heat it up to 80°C for a prepolymerization reaction for 4 h. Then add acrylic acid modified epoxy resin into the reaction system and stir the reaction until the content of isocyanate groups is constant. After separation and purification, epoxy resin modified UV curable polyurethane is obtained. Among them, the mass ratio of polycaprolactone diol, isophorone diisocyanate, acrylic acid modified epoxy resin, and dibutyltin dilaurate is 1:0.9:0.4:0.04;

[0060] 2. Prepare thinner: Mix toluene, xylene, and acetone in a mass ratio of 1:1:3 to obtain thinner;

[0061] Step 2: Mix graphene, epoxy resin modified UV curable polyurethane, 1,6 - hexanediol diacrylate, carbon powder, photoinitiator 1173, BYK - 163, and thinner evenly to obtain conductive carbon oil;

[0062] Among them, the raw materials of each component of the conductive carbon oil: by weight percentage, graphene is 18%, epoxy resin modified UV curable polyurethane is 30%, 1,6 - hexanediol diacrylate is 5%, carbon powder is 13%, photoinitiator 1173 is 3%, BYK - 163 is 3%, and thinner is 28%.

[0063] Comparative Example 2: Comparative Example 2 is based on Example 1 and is adjusted as follows: Use silver / graphene composite material instead of graphene / carbon nanotube composite material, and other processes remain unchanged. The specific content is as follows:

[0064] A preparation method of conductive carbon oil:

[0065] Step 1: 1. Prepare graphene / carbon nanotube composite material: (1) First, disperse graphene oxide into deionized water to obtain a 15 mg / mL graphene oxide dispersion; then transfer the graphene oxide dispersion to a high - pressure reaction kettle, and continue to add silver nitrate and ascorbic acid into it, ultrasonically disperse evenly, and then react at 150°C for 24 h to end the reaction; finally, the reaction product is frozen into blocks and freeze - dried to obtain silver / graphene composite material. Among them, the mass ratio of graphene oxide, silver nitrate, and ascorbic acid is 10:1.5:0.75;

[0066] 2. Preparation of epoxy resin-modified UV-curable polyurethane: (1) Add CELLOXIDE 2081 type epoxy resin into a reaction vessel and heat it up to 85°C. Then, under nitrogen protection, slowly dropwise add a mixed solution of acrylic acid, p-methoxyphenol, and triphenylphosphine into the vessel while stirring. After the addition is complete, heat it up to 110 ± 2°C and continue the reaction for 4 h to end the reaction and obtain acrylic acid-modified epoxy resin. Among them, the mass ratio of epoxy resin, acrylic acid, p-methoxyphenol, and triphenylphosphine is 1:0.4:0.0075:0.0075. (2) Add polycaprolactone diol, isophorone diisocyanate, dibutyltin dilaurate, and an appropriate amount of acetone into a reaction vessel. Under nitrogen protection, stir and heat it up to 80°C for a prepolymerization reaction for 4 h. Then, add acrylic acid-modified epoxy resin into the reaction system and stir the reaction until the isocyanate group content is constant. After separation and purification, epoxy resin-modified UV-curable polyurethane is obtained. Among them, the mass ratio of polycaprolactone diol, isophorone diisocyanate, acrylic acid-modified epoxy resin, and dibutyltin dilaurate is 1:0.9:0.4:0.04;

[0067] 3. Preparation of thinner: Mix toluene, xylene, and acetone in a mass ratio of 1:1:3 to obtain a thinner;

[0068] Step 2: Mix the graphene / silver composite material, epoxy resin-modified UV-curable polyurethane, 1,6-hexanediol diacrylate, carbon powder, photoinitiator 1173, BYK-163, and thinner evenly to obtain conductive carbon oil;

[0069] Among them, the raw materials of each component of the conductive carbon oil: by weight percentage, the graphene / silver composite material is 18%, the epoxy resin-modified UV-curable polyurethane is 30%, 1,6-hexanediol diacrylate is 5%, the carbon powder is 13%, the photoinitiator 1173 is 3%, BYK-163 is 3%, and the thinner is 28%.

[0070] Comparative Example 3: Comparative Example 3 is based on Example 1 and is adjusted as follows: 1,4-dihydroxy-2-butene is used instead of acrylic acid-modified epoxy resin, that is, the epoxy resin chain segment is not introduced, and other processes remain unchanged, specifically as follows:

[0071] A preparation method of conductive carbon oil:

[0072] Step 1: 1. Preparation of graphene / carbon nanotube composite material: (1) First, disperse graphene oxide in deionized water to obtain a graphene oxide dispersion with a concentration of 15 mg / mL. Then, transfer the graphene oxide dispersion to a high-pressure reactor, and continue to add silver nitrate and ascorbic acid thereto. After ultrasonic dispersion, react at 150 °C for 24 h to end the reaction. Finally, the reaction product is frozen into blocks and freeze-dried to obtain a silver / graphene composite material. Among them, the mass ratio of graphene oxide, silver nitrate, and ascorbic acid is 10:1.5:0.75. (2) Disperse isopropyltri(isostearoyl) titanate in an ethanol aqueous solution with a concentration of 75 wt%, and stir and mix for 45 min to obtain a 4 wt% isopropyltri(isostearoyl) titanate hydrolysis solution. (3) Add the silver / graphene composite material and carbon nanotubes to the isopropyltri(isostearoyl) titanate hydrolysis solution, stir and mix for 40 min, filter, and dry to obtain a graphene / carbon nanotube composite material. Among them, the mass ratio of the silver / graphene composite material, carbon nanotubes, and titanate coupling agent hydrolysis solution is 2:2:1.

[0073] 2. Preparation of modified UV-curable polyurethane: Add polycaprolactone diol, isophorone diisocyanate, dibutyltin dilaurate, and an appropriate amount of acetone to a reaction vessel. Under nitrogen protection, stir and heat up to 80 °C for a prepolymerization reaction for 4 h. Then, add 1,4-dihydroxy-2-butene to the reaction system, stir and react until the isocyanate group content is constant, and obtain the modified UV-curable polyurethane through separation and purification. Among them, the mass ratio of polycaprolactone diol, isophorone diisocyanate, 1,4-dihydroxy-2-butene, and dibutyltin dilaurate is 1:0.9:0.4:0.04.

[0074] 3. Preparation of thinner: Mix toluene, xylene, and acetone in a mass ratio of 1:1:3 to obtain a thinner.

[0075] Step 2: Mix the graphene / carbon nanotube composite material, modified UV-curable polyurethane, 1,6-hexanediol diacrylate, carbon powder, photoinitiator 1173, BYK-163, and thinner evenly to obtain a conductive carbon oil.

[0076] Among them, the raw materials of each component of the conductive carbon oil: by weight percentage, the graphene / carbon nanotube composite material is 18%, the modified UV-curable polyurethane is 30%, 1,6-hexanediol diacrylate is 5%, the carbon powder is 13%, the photoinitiator 1173 is 3%, BYK-163 is 3%, and the thinner is 28%.

[0077] Comparative Example 4: Comparative Example 4 is based on Example 1 and is adjusted as follows: Without adding 1,6-hexanediol diacrylate, that is, without adding an active diluent, and other processes remain unchanged. The specific details are as follows:

[0078] A preparation method of conductive carbon oil:

[0079] Step 1: 1. Prepare graphene / carbon nanotube composite material: (1) First, disperse graphene oxide into deionized water to obtain a graphene oxide dispersion with a concentration of 15 mg / mL; then transfer the graphene oxide dispersion to a high-pressure reaction kettle, and continue to add silver nitrate and ascorbic acid thereto, ultrasonically disperse evenly, and then react at 150 °C for 24 h to end the reaction; finally, the reaction product is frozen into blocks and freeze-dried to obtain silver / graphene composite material; wherein, the mass ratio of graphene oxide, silver nitrate, and ascorbic acid is 10:1.5:0.75; (2) Disperse isopropyltri(isostearoyl) titanate into an ethanol aqueous solution with a mass fraction of 75 wt%, stir and mix for 45 min to obtain a 4 wt% isopropyltri(isostearoyl) titanate hydrolysis solution; (3) Add the silver / graphene composite material and carbon nanotubes to the isopropyltri(isostearoyl) titanate hydrolysis solution, stir and mix for 40 min, filter and dry to obtain graphene / carbon nanotube composite material; wherein, the mass ratio of the silver / graphene composite material, carbon nanotubes, and titanate coupling agent hydrolysis solution is 2:2:1;

[0080] 2. Prepare epoxy resin-modified UV-curable polyurethane: (1) Add CELLOXIDE 2081 type epoxy resin to a reaction vessel and heat to 85 °C. Then, under nitrogen protection, slowly dropwise add a mixed solution of acrylic acid, p-methoxyphenol, and triphenylphosphine into the vessel, stir while dropping, and after dropping, heat to 110 ± 2 °C and continue to react for 4 h to end the reaction to obtain acrylic acid-modified epoxy resin; wherein, the mass ratio of epoxy resin, acrylic acid, p-methoxyphenol, and triphenylphosphine is 1:0.4:0.0075:0.0075; (2) Add polycaprolactone diol, isophorone diisocyanate, dibutyltin dilaurate, and an appropriate amount of acetone to a reaction vessel, stir and heat to 80 °C under nitrogen protection for a prepolymerization reaction for 4 h, then add acrylic acid-modified epoxy resin to the reaction system, stir and react until the isocyanate group content is constant, and after separation and purification, obtain epoxy resin-modified UV-curable polyurethane; wherein, the mass ratio of polycaprolactone diol, isophorone diisocyanate, acrylic acid-modified epoxy resin, and dibutyltin dilaurate is 1:0.9:0.4:0.04;

[0081] 3. Prepare thinner: Mix toluene, xylene, and acetone in a mass ratio of 1:1:3 to obtain thinner;

[0082] Step 2: Mix the graphene / carbon nanotube composite material, epoxy resin-modified UV-curable polyurethane, carbon powder, photoinitiator 1173, BYK-163, and thinner evenly to obtain conductive carbon oil;

[0083] Among them, the raw materials of each component of the conductive carbon oil: by weight percentage, 18% of graphene / carbon nanotube composite, 30% of epoxy resin modified UV curable polyurethane, 13% of carbon powder, 3% of photoinitiator 1173, 3% of BYK-163, and 33% of thinner.

[0084] Comparative Example 5: Comparative Example 5 is based on Example 1 and is adjusted as follows: without adding BYK-163, that is, without adding synergist, and other processes remain unchanged. Specifically as follows:

[0085] A preparation method of conductive carbon oil:

[0086] Step 1: 1. Prepare graphene / carbon nanotube composite: (1) First, disperse graphene oxide into deionized water to obtain a graphene oxide dispersion with a concentration of 15 mg / mL; then transfer the graphene oxide dispersion to a high-pressure reaction kettle, and continue to add silver nitrate and ascorbic acid thereto, ultrasonically disperse evenly, and then react at 150 °C for 24 h to end the reaction; finally, the reaction product is frozen into blocks and freeze-dried to obtain silver / graphene composite; among them, the mass ratio of graphene oxide, silver nitrate, and ascorbic acid is 10:1.5:0.75; (2) Disperse isopropyltri(isostearoyl)titanate into an ethanol aqueous solution with a concentration of 75 wt%, stir and mix for 45 min to obtain a 4 wt% isopropyltri(isostearoyl)titanate hydrolysis solution; (3) Add the silver / graphene composite and carbon nanotubes to the isopropyltri(isostearoyl)titanate hydrolysis solution, stir and mix for 40 min, filter and dry to obtain graphene / carbon nanotube composite; among them, the mass ratio of silver / graphene composite, carbon nanotubes, and titanate coupling agent hydrolysis solution is 2:2:1;

[0087] 2. Prepare epoxy resin modified UV curable polyurethane: (1) Add CELLOXIDE 2081 type epoxy resin to a reaction vessel and heat up to 85 °C. Then, under nitrogen protection, slowly dropwise add a mixed solution of acrylic acid, p-methoxyphenol, and triphenylphosphine into the vessel, stir while dropping, and after dropping, heat up to 110 ± 2 °C and continue to react for 4 h to end the reaction to obtain acrylic acid modified epoxy resin; among them, the mass ratio of epoxy resin, acrylic acid, p-methoxyphenol, and triphenylphosphine is 1:0.4:0.0075:0.0075; (2) Add polycaprolactone diol, isophorone diisocyanate, dibutyltin dilaurate, and an appropriate amount of acetone to a reaction vessel, stir and heat up to 80 °C under nitrogen protection for a prepolymerization reaction for 4 h. Then, add acrylic acid modified epoxy resin to the reaction system, stir and react until the isocyanate group content is constant, and after separation and purification, obtain epoxy resin modified UV curable polyurethane; among them, the mass ratio of polycaprolactone diol, isophorone diisocyanate, acrylic acid modified epoxy resin, and dibutyltin dilaurate is 1:0.9:0.4:0.04;

[0088] 3. Prepare thinner: Mix toluene, xylene, and acetone in a mass ratio of 1:1:3 to obtain the thinner.

[0089] Step 2: Mix the graphene / carbon nanotube composite, epoxy resin-modified UV-curable polyurethane, 1,6-hexanediol diacrylate, carbon powder, photoinitiator 1173, and thinner evenly to obtain the conductive carbon oil.

[0090] Among them, the raw materials of each component of the conductive carbon oil: by weight percentage, the graphene / carbon nanotube composite is 18%, the epoxy resin-modified UV-curable polyurethane is 30%, 1,6-hexanediol diacrylate is 5%, carbon powder is 13%, photoinitiator 1173 is 3%, and thinner is 31%.

[0091] Performance test: Evenly coat the conductive carbon oil prepared in Examples 1 to 3 and Comparative Examples 1 to 5 on the PET film, and the coating amount is 40 g / m 2 , then vacuum dry at 80 °C for 12 h, and then cure with 365 nm ultraviolet light for 2 h to obtain the conductive coating. Conduct relevant performance tests on the conductive coating, specifically as follows:

[0092] (1) Resistivity: Use a multimeter to test the resistivity of the conductive coating.

[0093] (2) Adhesion: Evaluate its adhesion grade according to the standard of GB / T 9286-2021.

[0094] (3) Hardness: Use a hardness tester to wipe its Shore hardness.

[0095] The test results of the above test contents are shown in Table 1 below:

[0096] Table 1

[0097]

[0098]

[0099] Result analysis: It can be seen from the data in Table 1 above that by comparing the examples and Comparative Examples 1 to 5, it can be seen that in the present invention, through the synergistic effect of the graphene / carbon nanotube composite, epoxy resin-modified UV-curable polyurethane, reactive diluent, and synergist, a conductive carbon oil with excellent conductive performance and excellent adhesion performance is comprehensively prepared, and it still has a high hardness after ultraviolet curing.

[0100] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A conductive carbon paste, characterized in that: It comprises the following components: by weight percentage, 16-20% of graphene / carbon nanotube composite, 25-35% of epoxy resin-modified UV-curable polyurethane, 2-8% of reactive diluent, 10-16% of carbon powder, 2-4% of photoinitiator, 2-4% of synergist, and 25-40% of thinner; The preparation method of the graphene / carbon nanotube composite is as follows: (1) First, graphene oxide is dispersed in deionized water to obtain a graphene oxide dispersion with a concentration of 10-20 mg / mL; then the graphene oxide dispersion is transferred to a high-pressure reactor, and silver nitrate and ascorbic acid are further added thereto, and ultrasonic dispersion is carried out until uniform, and then the reaction is carried out at 130-160 °C for 12-24 h to end the reaction; finally, the reaction product is frozen into blocks and freeze-dried to obtain a silver / graphene composite; (2) The titanate coupling agent is dispersed in an aqueous ethanol solution with a concentration of 75 wt%, and stirred and mixed for 30-60 min to obtain a titanate coupling agent hydrolysis solution with a concentration of 2-6 wt%; (3) The silver / graphene composite and carbon nanotubes are added to the titanate coupling agent hydrolysis solution, stirred and mixed for 20-60 min, filtered and dried to obtain a graphene / carbon nanotube composite.

2. A conductive carbon oil according to claim 1, characterized in that: The mass ratio of the graphene oxide, silver nitrate, and ascorbic acid is 10:(1-2):(0.5-1); the mass ratio of the silver / graphene composite, carbon nanotubes, and titanate coupling agent hydrolysis solution is 2:(1-3):

1.

3. A conductive carbon oil according to claim 1, wherein: The preparation method of the epoxy resin-modified UV-curable polyurethane is as follows: (1) Epoxy resin is added to a reaction vessel and heated to 80-90 °C, and then under nitrogen protection, a mixed solution of acrylic acid, p-methoxyphenol, and triphenylphosphine is slowly added dropwise to the vessel, and stirred while adding dropwise. After the addition is completed, the temperature is raised to 110±2 °C and the reaction is continued for 2-6 h to end the reaction, and an acrylic acid-modified epoxy resin is obtained; (2) Diol, diisocyanate, dibutyltin dilaurate, and acetone are added to a reaction vessel, and under nitrogen protection, the temperature is raised to 70-85 °C by stirring for a prepolymerization reaction for 2-6 h, and then acrylic acid-modified epoxy resin is added to the reaction system, and the reaction is stirred until the isocyanate group content is constant, and after separation and purification, an epoxy resin-modified UV-curable polyurethane is obtained.

4. The electrically conductive carbon paste according to claim 3, wherein: The mass ratio of the epoxy resin, acrylic acid, p-methoxyphenol, and triphenylphosphine is 1:(0.38-0.42):(0.005-0.01):(0.005-0.01); the mass ratio of the diol, diisocyanate, acrylic acid-modified epoxy resin, and dibutyltin dilaurate is 1:(0.8-1):(0.3-0.5):(0.03-0.05).

5. A conductive carbon oil according to claim 4, characterized in that: The epoxy equivalent of the epoxy resin is 200 g / eq.

6. A conductive carbon oil according to claim 1, characterized in that: The reactive diluent includes one or a combination of more of isodecyl acrylate, 1,6-hexanediol diacrylate, and pentaerythritol tetraacrylate.

7. A conductive carbon oil according to claim 1, characterized in that: The photoinitiator is photoinitiator 1173.

8. A conductive carbon oil according to claim 1, characterized in that: The synergist is BYK-163.

9. The electrically conductive carbon paste according to claim 1, characterized in that: The thinner is obtained by mixing toluene, xylene, and acetone in a mass ratio of 1:1:

3.

10. A preparation method of a conductive carbon oil according to any one of claims 1 to 9, characterized in that: Specifically: uniformly mix a graphene / carbon nanotube composite material, epoxy resin-modified UV-curable polyurethane, an active diluent, carbon powder, a photoinitiator, a synergist, and thinner to obtain a conductive carbon oil.

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