Photocuring conductive ink

Abstract

The invention discloses light-cured conductive ink which comprises the following raw materials in parts by weight: 10-15 parts of a modified prepolymer, 10-12 parts of nano-silver particles, 1-2 parts of a composite monomer, 0.5 part of a flatting agent and 0.3-0.5 part of a photoinitiator, by modifying a prepolymer and a monomer, a large number of carbon-carbon double bond groups and carbon-carbon double bonds are introduced as active pads, so that the conductive ink is better attached to a matrix material, meanwhile, the dispersity of nano-silver in resin is improved, and a compact structure formed by crosslinking of the double bonds can improve the hardness and impact resistance of the ink; a nano-silver conductive substrate in the resin is more fully contacted, a conductive structure is more easily formed, nano-silver is introduced to a monomer in a nucleation manner to form a composite monomer, the composite monomer has better conductivity than a common monomer, and the composite monomer is used as a monomer for connecting a modified prepolymer, so that the resistance of the resin can be effectively reduced, and the conductivity of the resin is improved. The overall conductivity of the conductive ink is improved.

Description

Technical Field

[0001] The invention relates to the field of conductive ink, and in particular to a photocurable conductive ink. Background Art

[0002] In recent years, as electronic products continue to develop in the direction of lightness, thinness and flexibility, flexible circuits that are both light, thin and flexible have become popular. Conductive ink, as a key material for preparing flexible circuits, has attracted much attention for its development. Conductive ink printing on the printing material plays the role of connecting various electronic components as a wire, greatly improving the utilization rate of the material, and has obvious advantages over traditional manufacturing methods. Conductive ink is generally composed of a base material and a conductive functional body. The base material includes a bonding phase and an additive, and the conductive functional body is a conductive material such as silver and copper. The working mechanism of conductive ink is different from that of traditional ink. At the minimum resolution angle of the human eye, the dots formed by traditional ink printing are discontinuous, but due to its high density, it presents a continuous image under the observation of the human eye, while the printing or coating of conductive ink must be continuous, and the combination between the conductive functional bodies needs to be very tight to form a good conductive network to ensure the normal use of its products.

[0003] Nanosilver conductive ink is considered to be the most suitable high-performance conductive ink for flexible electronic manufacturing. Due to the high sintering temperature of nanosilver, resin is usually added as a bonding phase to improve the performance of conductive ink, such as synthetic resin, photosensitive resin, natural resin and water-dispersible resin, etc. However, the addition of resin will cause the conductive ink to have a decreased conductivity. The resin needs to be modified to improve its conductivity. Epoxy resin, as a common resin, has good mechanical and physical and chemical properties. Under the action of UV light and photoinitiator, it reacts with monomers to form a solid structure of high molecular polymer, which can be used as a bonding phase for conductive ink. Summary of the invention

[0004] In order to solve the above problems, an object of the present invention is to provide a photocurable conductive ink.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A photocurable conductive ink comprises the following raw materials in parts by weight: 10-15 parts of a modified prepolymer, 10-12 parts of nano silver particles, 1-2 parts of a composite monomer, 0.5 parts of a leveling agent and 0.3-0.5 parts of a photoinitiator; The photocurable conductive ink is synthesized by the following steps: Add the modified prepolymer, nano silver particles, composite monomer, leveling agent and photoinitiator into a mixer, stir for 4-5 hours at 1000-1200 rpm, and perform light shielding and defoaming treatment to obtain UV light curing conductive ink; Under the action of UV light and photoinitiator, the modified prepolymer and the composite monomer of UV light-curing conductive ink polymerize to form a cross-linked structure and solidify into a film. When the resin is cured by UV to form a film, a large number of active groups of carbon-carbon double bonds will provide more active points, making it better fixed on the base material, and at the same time making the cross-linked network formed by the curing of the coating film denser, thereby increasing the hardness and impact resistance of the coating film, and the dense structure formed makes the nanosilver conductive matrix in the resin more fully contacted, and it is easier to form a conductive structure. The double-bond modified prepolymer and the composite monomer contain a large number of unsaturated double-bond groups, which play a certain role in the dispersion of nanosilver, so that the nanosilver is evenly dispersed in the resin, reducing the phenomenon of excessive local resistance due to uneven dispersion. The composite monomer introduces nucleated nanosilver on the organism through the in-situ composite reduction method, which has better conductivity than ordinary monomers. Using it as a monomer to connect the modified prepolymer can effectively reduce the resistance of the resin and improve the overall conductivity of the conductive ink. The modified prepolymer is prepared by the following steps: A1: Add di-n-butyltin dilaurate to pentaerythritol triacrylate, stir and slowly drop methylene di-p-phenylene diisocyanate, react at 300 rpm and 50°C for 4 hours, and evaporate under reduced pressure to obtain intermediate a. The amount ratio of pentaerythritol triacrylate, methylene di-p-phenylene diisocyanate and di-n-butyltin dilaurate is 1-1.2 mol: 1 mol: 0.005 mol; During the reaction, the isocyanate in methylene di-p-phenylene diisocyanate reacts with the alcohol hydroxyl group in pentaerythritol triacrylate to obtain intermediate a, and the isocyanate group is introduced;

[0006] A2: Add hydroquinone and tetrabutylammonium bromide to bisphenol A epoxy resin, stir and heat to 90°C, slowly add acrylic acid dropwise, react at 200rpm and 90°C for 4h, cool and cool to obtain intermediate b, the amount ratio of bisphenol A epoxy resin, acrylic acid, hydroquinone and tetrabutylammonium bromide is 1mol:2-2.2mol:0.01mol:0.01mol;

[0007] During the reaction, bisphenol A epoxy resin undergoes a ring-opening reaction with acrylic acid under the catalysis of tetrabutylammonium bromide, introducing terminal double bonds and hydroxyl groups. A3: Add di-n-butyltin dilaurate to intermediate b, stir and slowly add intermediate a, react at 300 rpm and 55°C for 4-6 hours, and evaporate under reduced pressure to obtain a modified prepolymer. The ratio of intermediate b, intermediate a and di-n-butyltin dilaurate is 1 mol: 2-2.2 mol: 0.005 mol; During the reaction, under the action of di-n-butyltin dilaurate, the hydroxyl group in intermediate b reacts with the isocyanate in intermediate a, introducing multiple terminal double bonds;

[0008] The composite monomer is prepared by the following steps: B1: Add hydroquinone to pentaerythritol glycidyl ether, stir and heat to 60°C, slowly drop acrylic acid and benzylamine, react at 300rpm and 90°C for 2.5-3h, and evaporate under reduced pressure to obtain intermediate 1, wherein the amount ratio of pentaerythritol glycidyl ether, acrylic acid, benzylamine and hydroquinone is 1 mol: 4-4.2 mol: 0.005 mol: 0.01 mol; During the reaction, the epoxy group in pentaerythritol glycidyl ether and the carboxyl group in acrylic acid undergo a ring-opening reaction to obtain an ester group and a hydroxyl group. Benzylamine and hydroquinone are used as catalysts and inhibitors. The ring-opening reaction introduces the terminal double bond into pentaerythritol glycidyl ether and generates a hydroxyl group. The specific structure of intermediate 1 is as follows;

[0009] B2: hydroquinone and benzylamine are added to intermediate 1, and maleic anhydride is added several times, and the reaction is carried out at 300 rpm and 90°C for 2-2.5 hours. After the system is cooled to 40°C, sodium bicarbonate solution is added thereto, and the pH is adjusted to 7-8. The intermediate 2 is obtained by rotary evaporation under reduced pressure. The molar concentration of the sodium bicarbonate solution is 0.1 mol / L, and the amount ratio of intermediate 1, maleic anhydride, hydroquinone and benzylamine is 1 mol: 4-4.2 mol: 0.005 mol: 0.01 mol; During the reaction, the hydroxyl group in the intermediate 1 undergoes a ring-opening reaction with maleic anhydride to generate an ester group and a carboxyl group, and then a sodium bicarbonate solution is used to neutralize the system. The carboxyl group reacts with the sodium bicarbonate solution to obtain a carboxylate, which has good water solubility.

[0010] B3: Slowly drip the silver ammonia solution into the intermediate 2, react at 300rpm and 50℃ for 30min, slowly drip the hydrazine hydrate solution, react at 300rpm and 50℃ for 1h, evaporate under reduced pressure, wash with deionized water three times, dry at 70℃ for 12h to obtain a composite monomer, the molar concentration of the silver ammonia solution is 0.1mol / L, the molar concentration of the hydrazine hydrate solution is 0.1mol / L, and the amount ratio of the intermediate 2, the silver ammonia solution and the hydrazine hydrate solution is 0.1-0.15mol:500mL:125mL; During the reaction, an in-situ composite reduction chemical method is adopted. In the case of hydrazine hydrate as a reducing agent, the sodium carboxylate salt and the silver ammonia solution in the intermediate 2 are used to make the nanosilver nucleate and aggregate on the intermediate 2, so that the conductive medium and the auxiliary agent are composited. Compared with the ordinary monomer, the composite monomer introduces nanosilver, thereby improving the conductivity of the monomer;

[0011] Furthermore, the nanosilver particles have a particle size of 50-100 nm; Further, the leveling agent is at least one of polyether-modified polydimethylsiloxane and alkyl-modified organic siloxane; Furthermore, the photoinitiator is at least one of 2-hydroxy-2-methyl-1-phenylpropanone and 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone.

[0012] The beneficial effects of the present invention are as follows: the present invention modifies the adhesive phase prepolymer resin and monomer in the conductive ink to obtain the modified prepolymer and the composite monomer, wherein the modified prepolymer and the composite monomer contain a large number of unsaturated double bonds, and a large number of active group carbon-carbon double bonds can provide more active points, so that the conductive ink is better fixed on the base material, and a large number of unsaturated double bonds can improve the dispersibility of nanosilver in the resin, so that the nanosilver is evenly dispersed in the resin, and the phenomenon of excessive local resistance of the nanosilver due to uneven dispersion is reduced; in view of the problem that the conductive ink has poor conductivity due to the addition of the adhesive phase resin, the monomer is modified and composited with nanosilver, so that the composite monomer has better conductivity than the ordinary monomer, and then the composite monomer and the modified prepolymer are subjected to UV light curing cross-linking film-forming process, so that the resin adhesive phase has good conductivity, and the dense film formed by cross-linking can effectively improve the mechanical properties of the ink, and the conductive functional body nanosilver in the resin can be tightly combined to quickly form a conductive network. DETAILED DESCRIPTION

[0013] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0014] The modified prepolymer is prepared by the following steps: A1: Add di-n-butyltin dilaurate to pentaerythritol triacrylate, stir and slowly drop methylene di-p-phenylene diisocyanate, react at 300 rpm and 50°C for 4 h, and evaporate under reduced pressure to obtain intermediate a. The amount ratio of pentaerythritol triacrylate, methylene di-p-phenylene diisocyanate and di-n-butyltin dilaurate is 1 mol: 1 mol: 0.005 mol; A2: Add hydroquinone and tetrabutylammonium bromide to bisphenol A epoxy resin, stir and heat to 90°C, slowly add acrylic acid dropwise, react at 200 rpm and 90°C for 4 hours, cool and cool to obtain intermediate b, the amount ratio of bisphenol A epoxy resin, acrylic acid, hydroquinone and tetrabutylammonium bromide is 1 mol: 2 mol: 0.01 mol: 0.01 mol; A3: Add di-n-butyltin dilaurate to intermediate b, stir and slowly add intermediate a, react at 300 rpm and 55°C for 4-6 hours, and evaporate under reduced pressure to obtain a modified prepolymer. The ratio of intermediate b, intermediate a and di-n-butyltin dilaurate is 1 mol: 2 mol: 0.005 mol; Example

[0015] The modified prepolymer is prepared by the following steps: A1: Add di-n-butyltin dilaurate to pentaerythritol triacrylate, stir and slowly drop methylene di-p-phenylene diisocyanate, react at 300 rpm and 50°C for 4 h, and evaporate under reduced pressure to obtain intermediate a. The amount ratio of pentaerythritol triacrylate, methylene di-p-phenylene diisocyanate and di-n-butyltin dilaurate is 1.1 mol: 1 mol: 0.005 mol; A2: Add hydroquinone and tetrabutylammonium bromide to bisphenol A epoxy resin, stir and heat to 90°C, slowly add acrylic acid dropwise, react at 200 rpm and 90°C for 4 hours, cool and cool to obtain intermediate b, the amount ratio of bisphenol A epoxy resin, acrylic acid, hydroquinone and tetrabutylammonium bromide is 1 mol: 2.1 mol: 0.01 mol: 0.01 mol; A3: Add di-n-butyltin dilaurate to intermediate b, stir and slowly add intermediate a, react at 300 rpm and 55°C for 4-6 hours, and evaporate under reduced pressure to obtain a modified prepolymer. The ratio of intermediate b, intermediate a and di-n-butyltin dilaurate is 1 mol: 2.1 mol: 0.005 mol; Example

[0016] The modified prepolymer is prepared by the following steps: A1: Add di-n-butyltin dilaurate to pentaerythritol triacrylate, stir and slowly drop methylene di-p-phenylene diisocyanate, react at 300 rpm and 50°C for 4 h, and evaporate under reduced pressure to obtain intermediate a. The amount ratio of pentaerythritol triacrylate, methylene di-p-phenylene diisocyanate and di-n-butyltin dilaurate is 1.2 mol: 1 mol: 0.005 mol; A2: Add hydroquinone and tetrabutylammonium bromide to bisphenol A epoxy resin, stir and heat to 90°C, slowly add acrylic acid dropwise, react at 200 rpm and 90°C for 4 hours, cool and cool to obtain intermediate b, the amount ratio of bisphenol A epoxy resin, acrylic acid, hydroquinone and tetrabutylammonium bromide is 1 mol: 2.2 mol: 0.01 mol: 0.01 mol; A3: Add di-n-butyltin dilaurate to intermediate b, stir and slowly add intermediate a, react at 300 rpm and 55°C for 4-6 hours, and evaporate under reduced pressure to obtain a modified prepolymer. The ratio of intermediate b, intermediate a and di-n-butyltin dilaurate is 1 mol: 2.2 mol: 0.005 mol; Experimental Example 4 The composite monomer is prepared by the following steps: B1: Add hydroquinone to pentaerythritol glycidyl ether, stir and heat to 60°C, slowly drop acrylic acid and benzylamine, react at 300rpm and 90°C for 2.5h, and evaporate under reduced pressure to obtain intermediate 1, in which the ratio of pentaerythritol glycidyl ether, acrylic acid, benzylamine and hydroquinone is 1mol:4mol:0.005mol:0.01mol; B2: hydroquinone and benzylamine were added to intermediate 1, and maleic anhydride was added several times, and the mixture was reacted at 300 rpm and 90°C for 2.5 hours. After the system was cooled to 40°C, sodium bicarbonate solution was added thereto, and the pH was adjusted to 7-8. The mixture was evaporated under reduced pressure to obtain intermediate 2. The molar concentration of the sodium bicarbonate solution was 0.1 mol / L, and the amount ratio of intermediate 1, maleic anhydride, hydroquinone and benzylamine was 1 mol: 4 mol: 0.005 mol: 0.01 mol; B3: Slowly drip the silver ammonia solution into the intermediate 2, react at 300rpm and 50℃ for 30min, slowly drip the hydrazine hydrate solution, and then react at 300rpm and 50℃ for 1h, evaporate under reduced pressure, wash with deionized water three times, and dry at 70℃ for 12h to obtain a composite monomer, the molar concentration of the silver ammonia solution is 0.1mol / L, the molar concentration of the hydrazine hydrate solution is 0.1mol / L, and the amount ratio of the intermediate 2, the silver ammonia solution and the hydrazine hydrate solution is 0.1mol:500mL:0.125L; Experimental Example 5 The composite monomer is prepared by the following steps: B1: Add hydroquinone to pentaerythritol glycidyl ether, stir and heat to 60°C, slowly drop acrylic acid and benzylamine, react at 300rpm and 90°C for 2.5h, and evaporate under reduced pressure to obtain intermediate 1, in which the amount ratio of pentaerythritol glycidyl ether, acrylic acid, benzylamine and hydroquinone is 1mol:4.1mol:0.005mol:0.01mol; B2: hydroquinone and benzylamine were added to intermediate 1, and maleic anhydride was added several times, and the reaction was carried out at 300 rpm and 90°C for 2.5 hours. After the system was cooled to 40°C, sodium bicarbonate solution was added thereto, and the pH was adjusted to 7-8. The intermediate 2 was obtained by rotary evaporation under reduced pressure. The molar concentration of the sodium bicarbonate solution was 0.1 mol / L, and the amount ratio of intermediate 1, maleic anhydride, hydroquinone and benzylamine was 1 mol: 4.1 mol: 0.005 mol: 0.01 mol; B3: Slowly drip the silver ammonia solution into the intermediate 2, react at 300rpm and 50℃ for 30min, slowly drip the hydrazine hydrate solution, react at 300rpm and 50℃ for 1h, evaporate under reduced pressure, wash with deionized water three times, dry at 70℃ for 12h to obtain a composite monomer, the molar concentration of the silver ammonia solution is 0.1mol / L, the molar concentration of the hydrazine hydrate solution is 0.1mol / L, and the amount ratio of the intermediate 2, the silver ammonia solution and the hydrazine hydrate solution is 0.13mol:500mL:0.125L; Experimental Example 6 The composite monomer is prepared by the following steps: B1: Add hydroquinone to pentaerythritol glycidyl ether, stir and heat to 60°C, slowly drop acrylic acid and benzylamine, react at 300rpm and 90°C for 3h, and evaporate under reduced pressure to obtain intermediate 1, in which the amount ratio of pentaerythritol glycidyl ether, acrylic acid, benzylamine and hydroquinone is 1mol:4.2mol:0.005mol:0.01mol; B2: hydroquinone and benzylamine were added to intermediate 1, and maleic anhydride was added several times, and the mixture was reacted at 300 rpm and 90°C for 2.5 h. After the system was cooled to 40°C, sodium bicarbonate solution was added thereto, and the pH was adjusted to 7-8. The mixture was evaporated under reduced pressure to obtain intermediate 2. The molar concentration of the sodium bicarbonate solution was 0.1 mol / L, and the amount ratio of intermediate 1, maleic anhydride, hydroquinone and benzylamine was 1 mol: 4.2 mol: 0.005 mol: 0.01 mol. B3: Slowly drip the silver ammonia solution into the intermediate 2, react at 300rpm and 50℃ for 30min, slowly drip the hydrazine hydrate solution, and then react at 300rpm and 50℃ for 1h, evaporate under reduced pressure, wash with deionized water three times, and dry at 70℃ for 12h to obtain a composite monomer, the molar concentration of the silver ammonia solution is 0.1mol / L, the molar concentration of the hydrazine hydrate solution is 0.1mol / L, and the amount ratio of the intermediate 2, the silver ammonia solution and the hydrazine hydrate solution is 0.15mol:500mL:0.125L; Experimental Example 7 A photocurable conductive ink comprises the following raw materials in parts by weight: 10 parts of the modified prepolymer of Example 1, 12 parts of nanosilver particles, 2 parts of the composite monomer of Example 4, 0.5 parts of a commercially available VOK-1080 leveling agent, and 0.5 parts of a commercially available 1173 photoinitiator; The photocurable conductive ink is synthesized by the following steps: The modified prepolymer of Example 1, nanosilver particles, the composite monomer of Example 4, the commercially available VOK-1080 leveling agent and the commercially available 1173 photoinitiator were added into a mixer, stirred at 1000 rpm for 5 hours, and subjected to light shielding and defoaming treatment to obtain a UV light-curable conductive ink; Experimental Example 8 A photocurable conductive ink comprises the following raw materials in parts by weight: 10 parts of the modified prepolymer of Example 2, 10 parts of nanosilver particles, 2 parts of the composite monomer of Example 5, 0.5 parts of a commercially available VOK-1080 leveling agent, and 0.5 parts of a commercially available 2959 photoinitiator; The photocurable conductive ink is synthesized by the following steps: The modified prepolymer of Example 2, nanosilver particles, the composite monomer of Example 5, the commercially available VOK-1080 leveling agent and the commercially available 2959 photoinitiator were added into a mixer, stirred at 1000 rpm for 4 hours, and subjected to light shielding and defoaming treatment to obtain a UV light-curable conductive ink; Experimental Example 9 A photocurable conductive ink comprises the following raw materials in parts by weight: 15 parts of the modified prepolymer of Example 3, 10 parts of nanosilver particles, 2 parts of the composite monomer of Example 6, 0.5 parts of a commercially available BYK333 leveling agent, and 0.5 parts of a commercially available 2959 photoinitiator; The photocurable conductive ink is synthesized by the following steps: The modified prepolymer of Example 3, nanosilver particles, the composite monomer of Example 6, the commercial BYK333 leveling agent and the commercial 2959 photoinitiator were added into a mixer, stirred at 1200 rpm for 5 hours, and subjected to light shielding and defoaming treatment to obtain a UV light-curable conductive ink; Comparative Example 1 Comparative Example 1 is a commercially available photocurable conductive ink; Comparative Example 2 Comparative Example 2: In Example 9, the modified prepolymer of Example 3 is replaced with a commercially available bisphenol A epoxy resin, and the other steps are completely the same as those of Example 9 to prepare a photocurable conductive ink; Comparative Example 3: In Example 9, the composite monomer of Example 6 is replaced with a commercially available hexanediol diacrylate monomer, and the other steps are completely the same as those of Example 9 to prepare a photocurable conductive ink; Take the photocurable conductive ink prepared in Example 7, Example 8, Example 8, Comparative Example 1, Comparative Example 2 and Comparative Example 3, apply the conductive ink on an insulating polyimide film by manual application using a 50 μm coating rod, UV light cure, measure the conductivity by a four-probe method, test the adhesion grade by a cross-hatch method, measure the hardness by a pencil test method, and measure the tensile recovery rate according to GB / T 528-2009 standard; The test results are shown in the following table:

[0017] From the test results in the table shown, it can be seen that compared with Comparative Example 1, Examples 7, 8 and 9 have better mechanical properties and conductive properties, and after 50 times of baking and washing, the conductive property loss is low; compared with Comparative Example 2, the modified prepolymer in Example 9 is replaced with a commercially available bisphenol A epoxy resin, and the mechanical properties are greatly reduced, and the conductive properties are also reduced. Compared with Comparative Example 3, the composite monomer in Example 9 is replaced with a commercially available hexanediol diacrylate monomer, and the mechanical properties are reduced to a certain extent, and the conductive properties are greatly reduced. It can be seen that the modified prepolymer and the composite monomer can effectively improve the mechanical properties of the conductive ink, and at the same time improve the conductive properties of the adhesive phase resin.

[0018] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A photocurable conductive ink, characterized in that: The invention comprises the following raw materials in parts by weight: 10-15 parts of modified prepolymer, 10-12 parts of nano silver particles, 1-2 parts of composite monomer, 0.5 parts of leveling agent and 0.3-0.5 parts of photoinitiator; The photocurable conductive ink is synthesized by the following steps: Add the modified prepolymer, nano silver particles, composite monomer, leveling agent and photoinitiator into a mixer, stir for 4-5 hours at 1000-1200 rpm, and perform light shielding and defoaming treatment to obtain a photocurable conductive ink.

2. The photocurable conductive ink according to claim 1, characterized in that: The modified prepolymer is prepared by the following steps: A1: Add di-n-butyltin dilaurate to pentaerythritol triacrylate, stir and slowly drop methylene di-p-phenylene diisocyanate, react at 300 rpm and 50°C for 4 h, and evaporate under reduced pressure to obtain intermediate a; A2: Add hydroquinone and tetrabutylammonium bromide to bisphenol A epoxy resin, stir and heat to 90°C, slowly add acrylic acid dropwise, react at 200 rpm and 90°C for 4 hours, cool and lower the temperature to obtain intermediate b; A3: Add di-n-butyltin dilaurate to intermediate b, stir and slowly add intermediate a, react at 300 rpm and 55°C for 4-6 hours, and evaporate under reduced pressure to obtain a modified prepolymer.

3. The photocurable conductive ink according to claim 2, characterized in that: In step A1, the ratio of pentaerythritol triacrylate, methylene di-p-phenylene diisocyanate and di-n-butyltin dilaurate is 1-1.2 mol: 1 mol: 0.005 mol; In step A2, the ratio of bisphenol A epoxy resin, acrylic acid, hydroquinone and tetrabutylammonium bromide is 1 mol: 2-2.2 mol: 0.01 mol: 0.01 mol; In step A3, the usage ratio of intermediate b, intermediate a and di-n-butyltin dilaurate is 1 mol:2-2.2 mol:0.005 mol.

4. The photocurable conductive ink according to claim 1, characterized in that: The composite monomer is prepared by the following steps: B1: Add hydroquinone to pentaerythritol glycidyl ether, stir and heat to 60°C, slowly drop acrylic acid and benzylamine, react at 300 rpm and 90°C for 2.5-3h, and evaporate under reduced pressure to obtain intermediate 1; B2: hydroquinone and benzylamine were added to intermediate 1, and maleic anhydride was added in several times, and the reaction was carried out at 300 rpm and 90°C for 2-2.5 hours. After the system was cooled to 40°C, sodium bicarbonate solution was added thereto, and the pH was adjusted to 7-8, and vacuum rotary evaporation was performed to obtain intermediate 2; B3: Slowly drip the silver ammonia solution into the intermediate 2, react at 300 rpm and 50°C for 30 min, slowly add the hydrazine hydrate solution, react at 300 rpm and 50°C for 1 h, evaporate under reduced pressure, wash with deionized water three times, and dry at 70°C for 12 h to obtain a composite monomer.

5. The photocurable conductive ink according to claim 4, characterized in that: In step B1, pentaerythritol glycidyl ether, acrylic acid, benzylamine and hydroquinone are used in an amount ratio of 1mol: 4-4.2mol: 0.005mol: 0.01mol; In step B2, the molar concentration of the sodium bicarbonate solution is 0.1 mol / L, and the ratio of the intermediate 1, maleic anhydride, hydroquinone and benzylamine is 1 mol: 4-4.2 mol: 0.005 mol: 0.01 mol; In step B3, the molar concentration of the silver ammonia solution is 0.1 mol / L, the molar concentration of the hydrazine hydrate solution is 0.1 mol / L, and the dosage ratio of the intermediate 2, the silver ammonia solution and the hydrazine hydrate solution is 0.1-0.15 mol:500 mL:125 mL.

6. The photocurable conductive ink according to claim 1, characterized in that: The particle size of the nano silver particles is 50-100 nm.

7. The photocurable conductive ink according to claim 1, characterized in that: The leveling agent is at least one of polyether-modified polydimethylsiloxane and alkyl-modified organic siloxane.

8. The photocurable conductive ink according to claim 1, characterized in that: The photoinitiator is at least one of 2-hydroxy-2-methyl-1-phenylpropanone and 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone.

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