A method for preparing a network-based high-adhesion conductive ink

Abstract

The application belongs to the technical field of ink, and particularly relates to a preparation method of high-adhesion conductive ink based on a network, which comprises the following steps: adding a dispersing agent, a defoaming agent, a pigment and water-based polyurethane into water, fully stirring to form a mixed solution; adding a conductive material and a fibrous filler into the mixed solution, rapidly stirring for 20-30 min, then adding a leveling agent and an anti-settling agent, and constant-temperature stirring to obtain the high-adhesion conductive ink. The application solves the problems of viscosity limitation and agglomeration of existing conductive fillers, utilizes the porous structure of polyvinyl alcohol polycondensate and the conductive modified fibrous filler to form a multi-dimensional network of porous conductive particles and conductive fibers, greatly improves the conductive network, and cooperates with the high adhesion of polydopamine and the high activity of polyurethane, so that the adhesion of the ink is effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of ink technology, specifically relating to a method for preparing a network-based high-adhesion conductive ink. Background Technology

[0002] Conductive ink is a type of functionalized ink, a special ink that forms conductive lines on a non-conductive substrate through a printing process. This conductive ink is mainly made by dispersing conductive fillers in a binder. Its conductivity mechanism relies on the formation of stable interconnections between the conductive fillers, resulting in continuous conductive channels. Therefore, conductive ink needs to contain sufficient conductive fillers to ensure the formation of stable conductive channels. However, as the amount of conductive filler used in conductive ink increases, the viscosity of the ink decreases significantly, limiting its coating application. Furthermore, conductive fillers are prone to agglomeration, causing localized increases in concentration and resulting in unstable conductive channels.

[0003] Therefore, the market urgently needs a conductive ink that combines conductivity and adhesion. Summary of the Invention

[0004] To address the problems in existing technologies, this invention provides a method for preparing a network-based high-adhesion conductive ink, which solves the problems of limited viscosity and agglomeration of existing conductive fillers. By utilizing porous polyvinyl alcohol condensate and conductive modified fiber fillers to form a multidimensional network of porous conductive particles and conductive fibers, the conductive network is greatly improved. In addition, the high viscosity of polydopamine and the high activity of polyurethane effectively enhance the adhesion of the ink.

[0005] To achieve the above technical objectives, the technical solution of the present invention is as follows: A method for preparing a network-based high-adhesion conductive ink includes the following steps: Step 1: Add dispersant, defoamer, pigment, and waterborne polyurethane to water and stir thoroughly to form a mixture. The temperature for thorough stirring is 20-30℃, and the stirring speed is 300-500 r / min. Step 2: Add conductive materials and fiber fillers to the mixture and stir rapidly for 20-30 minutes. Then add leveling agent and anti-settling agent and stir at a constant temperature to obtain high-adhesion conductive ink. The stirring speed of the rapid stirring is 400-600 r / min, and the temperature of the constant temperature stirring is 40-60℃, and the stirring speed is 300-500 r / min.

[0006] The mass ratio of the high-adhesion conductive ink is as follows: 50-80 parts of water-based polyurethane, 10-15 parts of conductive material, 20-30 parts of fiber filler, 0.5-1 part of dispersant, 0.3-0.5 parts of defoamer, 1-2 parts of leveling agent, 0.5-1 part of anti-settling agent, 2-4 parts of pigment, and 60-100 parts of water.

[0007] The solid content of the waterborne polyurethane is 30-40%.

[0008] The conductive material is a porous polyvinyl alcohol condensate. Polyvinyl alcohol condensate is formed when polyvinyl alcohol is heated to over 250°C, resulting in a polymer containing conjugated double bonds. To improve the adhesion between the conductive material and the ink resin, a porous polyvinyl alcohol condensate is used as the conductive material. Polyvinyl alcohol condensate itself contains conjugated double bonds, exhibiting good conductivity. Therefore, polyvinyl alcohol condensate can be used as a conductive material in ink. Simultaneously, the porous structure of the polyvinyl alcohol condensate ensures both current transmission channels and resin penetration through the porous structure, improving the stability and adhesion of the polyvinyl alcohol condensate in the ink. The preparation method of the porous polyvinyl alcohol condensate includes the following steps: a1, ethyl cellulose is placed in diethyl ether and stirred evenly, then sprayed at a constant temperature to obtain ethyl cellulose particles. The concentration of ethyl cellulose in ethanol is 400-600 g / L, the stirring speed is 200-400 r / min, the temperature of the constant temperature spray is 50-60°C, and the spray area is 100-200 cm². 2This step utilizes the solubility of ethyl cellulose in diethyl ether to form a homogeneous liquid-phase dispersion system. When the solution is sprayed at a constant temperature, the diethyl ether evaporates directly under the influence of temperature, yielding ethyl cellulose particles. a2, polyvinyl alcohol and methyl cellulose are added to water and stirred until homogeneous to obtain a solution. Then, ethyl cellulose particles are added and stirred for 10-20 minutes. After filtration, the solution is dried at a constant temperature to obtain coated ethyl cellulose particles. The mass ratio of polyvinyl alcohol to methyl cellulose is 3:2-4, the concentration of polyvinyl alcohol in water is 30-50 g / L, the stirring speed is 300-500 r / min, and the concentration of ethyl cellulose particles in the solution is... The concentration of polyvinyl alcohol (PVA) is 200-300 g / L, the stirring speed is 100-200 r / min, and the constant temperature drying temperature is 110-120℃. This step utilizes the solubility of PVA and methylcellulose in water to obtain a mixed solution of PVA and methylcellulose. Ethylcellulose particles are added and stirred to form a liquid film on the surface of the ethylcellulose particles. This liquid film uses PVA and methylcellulose as solutes and forms a PVA-methylcellulose composite film after drying. A3, the coated ethylcellulose particles are sintered for 5-10 min, then soaked in water for 20-30 min to obtain pre-formed particles. The sintering temperature is 250℃. The temperature is -253℃, and the atmosphere is nitrogen. The concentration of the coated ethyl cellulose particles in water is 100-200 g / L, and the temperature is 10-20℃. This step utilizes isothermal sintering to polycondense the polyvinyl alcohol on the surface of the ethyl cellulose particles to form a polymer containing conjugated double bonds. Methyl cellulose remains solid and inert at this temperature. Although ethyl cellulose softens at this temperature, methyl cellulose remains stable. The polyvinyl alcohol condensate remains stable at this temperature and is not affected by the softening of ethyl cellulose. When placed in water, ethyl cellulose and the polyvinyl alcohol condensate are insoluble and can form with water-soluble methyl cellulose. Rapid separation, a4: Porous polyvinyl alcohol condensate coated with ethyl cellulose particles is placed in diethyl ether and stirred evenly. After filtration and drying, porous polyvinyl alcohol condensate is obtained. The concentration of the porous polyvinyl alcohol condensate coated with ethyl cellulose particles in diethyl ether is 200-400 g / L, the stirring speed is 200-400 r / min, and the drying temperature is 50-60℃. This step utilizes the solubility of ethyl cellulose in diethyl ether and the insolubility of polyvinyl alcohol condensate in diethyl ether to directly form a rapid separation during stirring. After filtration and drying, polyvinyl alcohol condensate can be obtained. At the same time, the diethyl ether solution contains ethyl cellulose, which can be directly recycled and reused.This process uses ethyl cellulose as the core and methyl cellulose as the barrier agent, distributing polyvinyl alcohol (PVA) within the ethyl cellulose membrane. In-situ sintering yields a PVA condensate. The process utilizes the solubility of water and diethyl ether in methyl cellulose and ethyl cellulose, respectively, to achieve recyclability. This results in a porous, hollow PVA condensate, and the ethyl cellulose and methyl cellulose can be recycled and reused. The conductive material prepared by this process is a hollow PVA condensate with a porous structure.

[0009] The fiber filler is polydopamine-modified polyvinyl alcohol fiber. Polyvinyl alcohol fiber has advantages such as high strength, high modulus, and wear resistance, as well as excellent weather resistance, making it highly practical. However, polyvinyl alcohol itself is an insulator; therefore, polyvinyl alcohol fiber is also an insulating material, playing an insulating role in the ink and significantly impacting the overall ink composition. To address this issue, the surface of the polyvinyl alcohol fiber is modified to form a polydopamine surface film. The conductivity of polydopamine is used to improve the insulation of the fiber filler surface. Therefore, incorporating polydopamine-modified polyvinyl alcohol fiber into the ink creates a fibrous conductive structure. Combined with the high adhesion of polydopamine, this ensures excellent adhesion of the fiber filler in the ink, improving its stability and ensuring its connectivity with conductive materials. This forms a conductive network outside the conductive material, solving the problem of unstable conductive channels in the ink.The preparation method of the fiber filler includes the following steps: b1, placing polyvinyl alcohol fibers in an ethanol aqueous solution and stirring, filtering, and drying to obtain polyvinyl alcohol fibers, wherein the volume percentage of ethanol in the ethanol aqueous solution is 50-60%, and the concentration of polyvinyl alcohol fibers in the ethanol aqueous solution is 100-200 g / L, the stirring temperature is 30-40℃, the stirring speed is 300-500 r / min, and the drying temperature is 110-120℃; this step utilizes the dissolution of ethanol and water to wash the polyvinyl alcohol fibers, completely removing surface dust to obtain clean polyvinyl alcohol fibers; b2, adding dopa... Amine and sodium bicarbonate are added to water and stirred until homogeneous to obtain a weakly alkaline solution. Polyvinyl alcohol (PVA) fibers are then added, stirred for 20-30 minutes, and filtered to obtain coated PVA fibers. The pH of the weakly alkaline solution is 8.3-8.5, and the concentration of dopamine in the water is 100-200 g / L. The concentration of PVA fibers in the weakly alkaline solution is 30-60 g / L. This step utilizes the solubility of dopamine and sodium bicarbonate in water to form a stable solution, while simultaneously creating an alkaline environment for polydopamine. As the PVA fibers are added, dopamine directly aggregates onto the surface of the PVA fibers due to its own adhesion properties. During filtration, the surface of the PVA fibers... A liquid film is deposited on the surface; this liquid film is a dopamine-sodium bicarbonate aqueous film. b3, the coated polyvinyl alcohol fiber is placed in a reaction vessel and kept at a constant temperature for 1-2 hours. After purging and cooling, pre-made polydopamine-modified polyvinyl alcohol fiber is obtained. The atmosphere for the constant temperature settling is a mixture of nitrogen, oxygen, and water vapor, with a volume ratio of nitrogen, oxygen, and water vapor of 10:3:2 and a temperature of 60-70℃. The purging uses dry nitrogen at a temperature of 110-120℃ and a purging speed of 5-10 mL / min. This step involves in-situ polycondensation under humid conditions, where the dopamine undergoes oxidative polymerization under the combined action of oxygen and a weak alkali. The double bond conjugated system of dopamine forms a conductive network structure on the surface of polyvinyl alcohol fiber; b4, the pre-prepared polydopamine-modified polyvinyl alcohol fiber is placed in water and ultrasonically treated for 10-20 min, filtered and dried to obtain polydopamine-modified polyvinyl alcohol fiber. The concentration of the pre-prepared polydopamine-modified polyvinyl alcohol fiber in water is 200-400 g / L, the ultrasonic treatment temperature is 20-30 min, the frequency is 60-90 kHz, and the drying temperature is 110-120℃. This step uses ultrasound to dissolve sodium bicarbonate in water and form a porous structure in the polydopamine. The polydopamine is insoluble in water and still maintains the porous structure.Therefore, the fiber filler prepared by this process is polydopamine-modified polyvinyl alcohol fiber, and polydopamine has a porous structure. When this polydopamine-modified polyvinyl alcohol fiber is added to the ink, the adhesiveness of polydopamine can form a connection with the conductive material, thereby achieving a network structure. At the same time, the porosity of the porous polydopamine can ensure the resin permeability and fixation, forming a clamping effect. It can also utilize the active groups to form a chemical connection with the polyurethane resin, achieving excellent fixation effect.

[0010] The dispersant used is zinc stearate.

[0011] The defoamer used is polydimethylsiloxane.

[0012] The pigment used is one of Permanent Red F2R, Permanent Red F4R, Pigment Red 22, or Solid Red Blue Lotus.

[0013] The leveling agent is polyether-modified polydimethylsiloxane, which can enhance surface smoothness and gloss, and improve anti-blocking properties.

[0014] The anti-settling agent is made of ultrafine fumed silica with a particle size of 7-14 nm. This anti-settling agent can not only form a network structure to maintain ink uniformity, but also enhance adhesion and maintain excellent adhesion performance.

[0015] As can be seen from the above description, the present invention has the following advantages: 1. This invention solves the problems of limited viscosity and agglomeration of existing conductive fillers. It utilizes porous polyvinyl alcohol condensate and conductive modified fiber filler to form a multidimensional network of porous conductive particles and conductive fibers, which greatly improves the conductive network. In addition, the high viscosity of polydopamine and the high activity of polyurethane effectively improve the adhesion of ink.

[0016] 2. This invention utilizes high-temperature polycondensation of polyvinyl alcohol to form a polymer containing conjugated double bonds, which not only has good electrical conductivity, but also has a hollow and porous structure, ensuring the internal and external connectivity of the resin material in the ink and improving the fixation and stability of the conductive material in the ink.

[0017] 3. This invention utilizes polydopamine to modify the surface of polyvinyl alcohol fibers. This modification can improve the adhesion of the polyvinyl alcohol fiber surface and give it a porous surface structure, forming the connectivity of the fiber filler from both physical and chemical aspects. At the same time, polydopamine forms a conductive network on the surface of the insulating polyvinyl alcohol fibers, and forms an integral conductive network by connecting with the porous polyvinyl alcohol condensate of the conductive material. Detailed Implementation

[0018] The present invention will be described in detail with reference to the embodiments, but the claims of the present invention are not intended to limit the scope of the invention. Example 1

[0019] A method for preparing a network-based high-adhesion conductive ink includes the following steps: Step 1: Add dispersant, defoamer, pigment, and waterborne polyurethane to water and stir thoroughly to form a mixture. The temperature for thorough stirring is 30°C and the stirring speed is 500 r / min. Step 2: Add conductive material and fiber filler to the mixture and stir rapidly for 30 minutes. Then add leveling agent and anti-settling agent and stir at a constant temperature to obtain high-adhesion conductive ink. The stirring speed of the rapid stirring is 600 r / min, and the temperature of the constant temperature stirring is 60℃ with a stirring speed of 500 r / min.

[0020] The mass ratio of the high-adhesion conductive ink is as follows: 50 parts water-based polyurethane, 10 parts conductive material, 20 parts fiber filler, 0.5 parts dispersant, 0.3 parts defoamer, 1 part leveling agent, 0.5 parts anti-settling agent, 2 parts pigment, and 60 parts water.

[0021] The solid content of the waterborne polyurethane is 30%.

[0022] The conductive material is a porous polyvinyl alcohol condensate, and the conductive material is a hollow polyvinyl alcohol condensate with a porous structure. The preparation method of the porous polyvinyl alcohol condensate includes the following steps: a1, ethyl cellulose is placed in diethyl ether and stirred evenly, and then sprayed at a constant temperature to obtain ethyl cellulose particles. The concentration of ethyl cellulose in ethanol is 400 g / L, the stirring speed is 400 r / min, the temperature of the constant temperature spray is 60℃, and the spray area is 200 cm². 2 a2, Polyvinyl alcohol and methylcellulose are added to water and stirred evenly to obtain a solution. Then, ethylcellulose particles are added and stirred for 20 minutes. After filtration, the solution is dried at a constant temperature to obtain coated ethylcellulose particles. The mass ratio of polyvinyl alcohol to methylcellulose is 3:2, the concentration of polyvinyl alcohol in water is 30 g / L, the stirring speed is 500 r / min, the concentration of ethylcellulose particles in the solution is 200 g / L, the stirring speed is 100 r / min, and the drying temperature is 120℃. a3. The coated ethyl cellulose particles are sintered for 10 minutes, then soaked in water for 30 minutes to obtain pre-formed particles; the sintering temperature is 253℃, and the atmosphere is nitrogen; the concentration of the coated ethyl cellulose particles in water is 100 g / L, and the temperature is 20℃; a4. The porous polyvinyl alcohol condensate-coated ethyl cellulose particles are placed in diethyl ether and stirred evenly, filtered, and dried to obtain porous polyvinyl alcohol condensate; the concentration of the porous polyvinyl alcohol condensate-coated ethyl cellulose particles in diethyl ether is 200 g / L, the stirring speed is 400 r / min, and the drying temperature is 60℃.

[0023] The fiber filler is polydopamine-modified polyvinyl alcohol fiber, and the polydopamine has a porous structure. The preparation method of the fiber filler includes the following steps: b1, placing polyvinyl alcohol fiber in an ethanol aqueous solution and stirring, filtering and drying to obtain polyvinyl alcohol fiber, wherein the volume percentage of ethanol in the ethanol aqueous solution is 60%, and the concentration of polyvinyl alcohol fiber in the ethanol aqueous solution is 100 g / L, the stirring temperature is 40℃, the stirring speed is 500 r / min, and the drying temperature is 120℃; b2, adding dopamine and sodium bicarbonate to water and stirring evenly to obtain a weak alkaline solution, then placing the polyvinyl alcohol fiber in the solution, stirring for 30 min and filtering to obtain coated polyvinyl alcohol fiber; the pH of the weak alkaline solution is 8.5, and the concentration of dopamine in the water is 100 g / L. b3, The concentration of the polyvinyl alcohol fiber in the weak alkaline solution is 30 g / L; b4, The coated polyvinyl alcohol fiber is placed in a reaction vessel and kept at a constant temperature for 2 hours, then purged and cooled to obtain pre-prepared polydopamine modified polyvinyl alcohol fiber. The atmosphere for the constant temperature standing is a mixture of nitrogen, oxygen and water vapor, and the volume ratio of nitrogen, oxygen and water vapor is 10:3:2, and the temperature is 70℃; the purging uses dry nitrogen at a temperature of 120℃ and a purging speed of 10 mL / min; b5, The pre-prepared polydopamine modified polyvinyl alcohol fiber is placed in water and ultrasonically treated for 20 min, filtered and dried to obtain polydopamine modified polyvinyl alcohol fiber. The concentration of the pre-prepared polydopamine modified polyvinyl alcohol fiber in water is 200 g / L, the ultrasonic treatment temperature is 30 min, the frequency is 90 kHz, and the drying temperature is 120℃.

[0024] The dispersant used is zinc stearate.

[0025] The defoamer used is polydimethylsiloxane.

[0026] The pigment used is Permanent Red F2R.

[0027] The leveling agent is polyether-modified polydimethylsiloxane.

[0028] The anti-settling agent is made of ultrafine fumed silica with a particle size of 7-14 nm. Example 2

[0029] A method for preparing a network-based high-adhesion conductive ink includes the following steps: Step 1: Add dispersant, defoamer, pigment, and waterborne polyurethane to water and stir thoroughly to form a mixture. The temperature for thorough stirring is 20°C and the stirring speed is 300 r / min. Step 2: Add conductive material and fiber filler to the mixture and stir rapidly for 20 minutes. Then add leveling agent and anti-settling agent and stir at a constant temperature to obtain high-adhesion conductive ink. The stirring speed of the rapid stirring is 400 r / min, and the temperature of the constant temperature stirring is 40℃ with a stirring speed of 300 r / min.

[0030] The mass ratio of the high-adhesion conductive ink is as follows: 80 parts water-based polyurethane, 15 parts conductive material, 30 parts fiber filler, 1 part dispersant, 0.5 parts defoamer, 2 parts leveling agent, 1 part anti-settling agent, 4 parts pigment, and 100 parts water.

[0031] The solid content of the waterborne polyurethane is 40%.

[0032] The conductive material is a porous polyvinyl alcohol condensate, and the conductive material is a hollow polyvinyl alcohol condensate with a porous structure. The preparation method of the porous polyvinyl alcohol condensate includes the following steps: a1, ethyl cellulose is placed in diethyl ether and stirred evenly, and then sprayed at a constant temperature to obtain ethyl cellulose particles. The concentration of ethyl cellulose in ethanol is 600 g / L, the stirring speed is 200 r / min, the temperature of the constant temperature spray is 50°C, and the spray area is 100 cm². 2 a2, Polyvinyl alcohol and methylcellulose are added to water and stirred evenly to obtain a solution. Then, ethylcellulose particles are added and stirred for 10 minutes. After filtration, the solution is dried at a constant temperature to obtain coated ethylcellulose particles. The mass ratio of polyvinyl alcohol to methylcellulose is 3:4, the concentration of polyvinyl alcohol in water is 50 g / L, the stirring speed is 300 r / min, the concentration of ethylcellulose particles in the solution is 300 g / L, the stirring speed is 100 r / min, and the drying temperature is 110℃. a3, Sinter the coated ethyl cellulose particles for 5 minutes, then soak them in water for 20 minutes to obtain pre-formed particles; the sintering temperature is 250℃, and the atmosphere is a nitrogen atmosphere; the concentration of the coated ethyl cellulose particles in the water is 200 g / L, and the temperature is 10℃; a4, Place the porous polyvinyl alcohol condensate-coated ethyl cellulose particles in diethyl ether and stir evenly, filter, and dry to obtain porous polyvinyl alcohol condensate; the concentration of the porous polyvinyl alcohol condensate-coated ethyl cellulose particles in diethyl ether is 400 g / L, the stirring speed is 200 r / min, and the drying temperature is 50℃.

[0033] The fiber filler is polydopamine-modified polyvinyl alcohol fiber, and the polydopamine has a porous structure. The preparation method of the fiber filler includes the following steps: b1, placing polyvinyl alcohol fiber in an ethanol aqueous solution and stirring, filtering and drying to obtain polyvinyl alcohol fiber, wherein the volume percentage of ethanol in the ethanol aqueous solution is 60%, and the concentration of polyvinyl alcohol fiber in the ethanol aqueous solution is 200 g / L, the stirring temperature is 30℃, the stirring speed is 300 r / min, and the drying temperature is 110℃; b2, adding dopamine and sodium bicarbonate to water and stirring evenly to obtain a weak alkaline solution, then placing the polyvinyl alcohol fiber in the solution, stirring for 20 min and filtering to obtain coated polyvinyl alcohol fiber; the pH of the weak alkaline solution is 8.3, and the concentration of dopamine in the water is 200 g / L. b3, The concentration of the polyvinyl alcohol fiber in the weak alkaline solution is 60 g / L; b4, The coated polyvinyl alcohol fiber is placed in a reaction vessel and kept at a constant temperature for 1 hour, then purged and cooled to obtain pre-prepared polydopamine modified polyvinyl alcohol fiber. The atmosphere for the constant temperature standing is a mixture of nitrogen, oxygen and water vapor, and the volume ratio of nitrogen, oxygen and water vapor is 10:3:2, and the temperature is 60℃; the purging uses dry nitrogen at a temperature of 110℃ and a purging speed of 10 mL / min; b5, The pre-prepared polydopamine modified polyvinyl alcohol fiber is placed in water and ultrasonically treated for 10 min, filtered and dried to obtain polydopamine modified polyvinyl alcohol fiber. The concentration of the pre-prepared polydopamine modified polyvinyl alcohol fiber in water is 400 g / L, the ultrasonic treatment temperature is 20 min, the frequency is 60 kHz, and the drying temperature is 110℃.

[0034] The dispersant used is zinc stearate.

[0035] The defoamer used is polydimethylsiloxane.

[0036] The pigment used is Permanent Red F4R.

[0037] The leveling agent is polyether-modified polydimethylsiloxane.

[0038] The anti-settling agent is made of ultrafine fumed silica with a particle size of 7-14 nm. Example 3

[0039] A method for preparing a network-based high-adhesion conductive ink includes the following steps: Step 1: Add dispersant, defoamer, pigment, and waterborne polyurethane to water and stir thoroughly to form a mixture. The temperature for thorough stirring is 25°C and the stirring speed is 400 r / min. Step 2: Add conductive material and fiber filler to the mixture and stir rapidly for 25 minutes. Then add leveling agent and anti-settling agent and stir at a constant temperature to obtain high-adhesion conductive ink. The stirring speed of the rapid stirring is 500 r / min, and the temperature of the constant temperature stirring is 50℃ with a stirring speed of 400 r / min.

[0040] The mass ratio of the high-adhesion conductive ink is as follows: 70 parts water-based polyurethane, 12 parts conductive material, 25 parts fiber filler, 0.8 parts dispersant, 0.4 parts defoamer, 1 part leveling agent, 0.8 parts anti-settling agent, 3 parts pigment, and 80 parts water.

[0041] The solid content of the waterborne polyurethane is 30%.

[0042] The conductive material is a porous polyvinyl alcohol condensate, and the conductive material is a hollow polyvinyl alcohol condensate with a porous structure. The preparation method of the porous polyvinyl alcohol condensate includes the following steps: a1, ethyl cellulose is placed in diethyl ether and stirred evenly, and then sprayed at a constant temperature to obtain ethyl cellulose particles. The concentration of ethyl cellulose in ethanol is 500 g / L, the stirring speed is 300 r / min, the temperature of the constant temperature spray is 55℃, and the spray area is 150 cm². 2 a2, Polyvinyl alcohol and methylcellulose are added to water and stirred evenly to obtain a solution. Then, ethylcellulose particles are added and stirred for 15 minutes. After filtration, the solution is dried at a constant temperature to obtain coated ethylcellulose particles. The mass ratio of polyvinyl alcohol to methylcellulose is 1:1, the concentration of polyvinyl alcohol in water is 40 g / L, the stirring speed is 400 r / min, the concentration of ethylcellulose particles in the solution is 250 g / L, the stirring speed is 150 r / min, and the drying temperature is 115℃. a3. The coated ethyl cellulose particles are sintered for 8 minutes, then soaked in water for 25 minutes to obtain pre-formed particles; the sintering temperature is 252℃, and the atmosphere is nitrogen; the concentration of the coated ethyl cellulose particles in water is 150 g / L, and the temperature is 15℃; a4. The porous polyvinyl alcohol condensate-coated ethyl cellulose particles are placed in diethyl ether and stirred evenly, filtered, and dried to obtain porous polyvinyl alcohol condensate; the concentration of the porous polyvinyl alcohol condensate-coated ethyl cellulose particles in diethyl ether is 300 g / L, the stirring speed is 300 r / min, and the drying temperature is 55℃.

[0043] The fiber filler is polydopamine-modified polyvinyl alcohol fiber, and the polydopamine has a porous structure. The preparation method of the fiber filler includes the following steps: b1, placing polyvinyl alcohol fiber in an ethanol-water solution and stirring, filtering and drying to obtain polyvinyl alcohol fiber, wherein the volume percentage of ethanol in the ethanol-water solution is 55%, and the concentration of polyvinyl alcohol fiber in the ethanol-water solution is 150 g / L, the stirring temperature is 35℃, the stirring speed is 400 r / min, and the drying temperature is 115℃; b2, adding dopamine and sodium bicarbonate to water and stirring evenly to obtain a weak alkaline solution, then placing the polyvinyl alcohol fiber in the solution, stirring for 25 min and filtering to obtain coated polyvinyl alcohol fiber; the pH of the weak alkaline solution is 8.4, and the concentration of dopamine in the water is 15%. b3, The concentration of the polyvinyl alcohol fiber in the weak alkaline solution is 50 g / L. The coated polyvinyl alcohol fiber is placed in a reaction vessel and kept at a constant temperature for 2 hours. After purging and cooling, pre-prepared polydopamine-modified polyvinyl alcohol fiber is obtained. The atmosphere for constant temperature stabilization is a mixture of nitrogen, oxygen, and water vapor, with a volume ratio of 10:3:2 and a temperature of 65°C. Dry nitrogen is used for purging at a temperature of 115°C and a purging speed of 8 mL / min. b4, The pre-prepared polydopamine-modified polyvinyl alcohol fiber is placed in water and ultrasonically treated for 15 minutes. After filtration and drying, polydopamine-modified polyvinyl alcohol fiber is obtained. The concentration of the pre-prepared polydopamine-modified polyvinyl alcohol fiber in water is 300 g / L. The ultrasonic treatment temperature is 25 minutes, the frequency is 80 kHz, and the drying temperature is 115°C.

[0044] The dispersant used is zinc stearate.

[0045] The defoamer used is polydimethylsiloxane.

[0046] The pigment used is a robust red lotus.

[0047] The leveling agent is polyether-modified polydimethylsiloxane.

[0048] The anti-settling agent is made of ultrafine fumed silica with a particle size of 7-14 nm.

[0049] Comparative Example 1 A method for preparing a network-based high-adhesion conductive ink includes the following steps: Step 1: Add dispersant, defoamer, pigment, and waterborne polyurethane to water and stir thoroughly to form a mixture. The temperature for thorough stirring is 25°C and the stirring speed is 400 r / min. Step 2: Add conductive material and fiber filler to the mixture and stir rapidly for 25 minutes. Then add leveling agent and anti-settling agent and stir at a constant temperature to obtain high-adhesion conductive ink. The stirring speed of the rapid stirring is 500 r / min, and the temperature of the constant temperature stirring is 50℃ with a stirring speed of 400 r / min.

[0050] The mass ratio of the high-adhesion conductive ink is as follows: 70 parts water-based polyurethane, 12 parts conductive material, 25 parts fiber filler, 0.8 parts dispersant, 0.4 parts defoamer, 1 part leveling agent, 0.8 parts anti-settling agent, 3 parts pigment, and 80 parts water.

[0051] The solid content of the waterborne polyurethane is 30%.

[0052] The conductive material is a porous polyvinyl alcohol condensate, and the conductive material is a hollow polyvinyl alcohol condensate with a porous structure. The preparation method of the porous polyvinyl alcohol condensate includes the following steps: a1, ethyl cellulose is placed in diethyl ether and stirred evenly, and then sprayed at a constant temperature to obtain ethyl cellulose particles. The concentration of ethyl cellulose in ethanol is 500 g / L, the stirring speed is 300 r / min, the temperature of the constant temperature spray is 55℃, and the spray area is 150 cm². 2 a2, Polyvinyl alcohol and methylcellulose are added to water and stirred evenly to obtain a solution. Then, ethylcellulose particles are added and stirred for 15 minutes. After filtration, the solution is dried at a constant temperature to obtain coated ethylcellulose particles. The mass ratio of polyvinyl alcohol to methylcellulose is 1:1, the concentration of polyvinyl alcohol in water is 40 g / L, the stirring speed is 400 r / min, the concentration of ethylcellulose particles in the solution is 250 g / L, the stirring speed is 150 r / min, and the drying temperature is 115℃. a3. The coated ethyl cellulose particles are sintered for 8 minutes, then soaked in water for 25 minutes to obtain pre-formed particles; the sintering temperature is 252℃, and the atmosphere is nitrogen; the concentration of the coated ethyl cellulose particles in water is 150 g / L, and the temperature is 15℃; a4. The porous polyvinyl alcohol condensate-coated ethyl cellulose particles are placed in diethyl ether and stirred evenly, filtered, and dried to obtain porous polyvinyl alcohol condensate; the concentration of the porous polyvinyl alcohol condensate-coated ethyl cellulose particles in diethyl ether is 300 g / L, the stirring speed is 300 r / min, and the drying temperature is 55℃.

[0053] The fiber filler is made of polyvinyl alcohol fiber. The dispersant used is zinc stearate.

[0054] The defoamer used is polydimethylsiloxane.

[0055] The pigment used is a robust red lotus.

[0056] The leveling agent is polyether-modified polydimethylsiloxane.

[0057] The anti-settling agent is made of ultrafine fumed silica with a particle size of 7-14 nm.

[0058] Comparative Example 2 A method for preparing a network-based high-adhesion conductive ink includes the following steps: Step 1: Add dispersant, defoamer, pigment, and waterborne polyurethane to water and stir thoroughly to form a mixture. The temperature for thorough stirring is 25°C and the stirring speed is 400 r / min. Step 2: Add conductive material and fiber filler to the mixture and stir rapidly for 25 minutes. Then add leveling agent and anti-settling agent and stir at a constant temperature to obtain high-adhesion conductive ink. The stirring speed of the rapid stirring is 500 r / min, and the temperature of the constant temperature stirring is 50℃ with a stirring speed of 400 r / min.

[0059] The mass ratio of the high-adhesion conductive ink is as follows: 70 parts water-based polyurethane, 12 parts conductive material, 25 parts fiber filler, 0.8 parts dispersant, 0.4 parts defoamer, 1 part leveling agent, 0.8 parts anti-settling agent, 3 parts pigment, and 80 parts water.

[0060] The solid content of the waterborne polyurethane is 30%.

[0061] The conductive material is carbon black.

[0062] The fiber filler is polydopamine-modified polyvinyl alcohol fiber, and the polydopamine has a porous structure. The preparation method of the fiber filler includes the following steps: b1, placing polyvinyl alcohol fiber in an ethanol-water solution and stirring, filtering and drying to obtain polyvinyl alcohol fiber, wherein the volume percentage of ethanol in the ethanol-water solution is 55%, and the concentration of polyvinyl alcohol fiber in the ethanol-water solution is 150 g / L, the stirring temperature is 35℃, the stirring speed is 400 r / min, and the drying temperature is 115℃; b2, adding dopamine and sodium bicarbonate to water and stirring evenly to obtain a weak alkaline solution, then placing the polyvinyl alcohol fiber in the solution, stirring for 25 min and filtering to obtain coated polyvinyl alcohol fiber; the pH of the weak alkaline solution is 8.4, and the concentration of dopamine in the water is 15%. b3, The concentration of the polyvinyl alcohol fiber in the weak alkaline solution is 50 g / L. The coated polyvinyl alcohol fiber is placed in a reaction vessel and kept at a constant temperature for 2 hours. After purging and cooling, pre-prepared polydopamine-modified polyvinyl alcohol fiber is obtained. The atmosphere for constant temperature stabilization is a mixture of nitrogen, oxygen, and water vapor, with a volume ratio of 10:3:2 and a temperature of 65°C. Dry nitrogen is used for purging at a temperature of 115°C and a purging speed of 8 mL / min. b4, The pre-prepared polydopamine-modified polyvinyl alcohol fiber is placed in water and ultrasonically treated for 15 minutes. After filtration and drying, polydopamine-modified polyvinyl alcohol fiber is obtained. The concentration of the pre-prepared polydopamine-modified polyvinyl alcohol fiber in water is 300 g / L. The ultrasonic treatment temperature is 25 minutes, the frequency is 80 kHz, and the drying temperature is 115°C.

[0063] The dispersant used is zinc stearate.

[0064] The defoamer used is polydimethylsiloxane.

[0065] The pigment used is a robust red lotus.

[0066] The leveling agent is polyether-modified polydimethylsiloxane.

[0067] The anti-settling agent is made of ultrafine fumed silica with a particle size of 7-14 nm.

[0068] Performance testing The inks of Examples 1-3 and Comparative Examples 1-2 were used as test samples for performance testing, and the results are as follows:

[0069] The resistance value is determined by coating conductive ink onto a polyester substrate, drying and cutting it into 25×100mm samples, and testing them using a low-current DC resistance tester with copper blocks of 1.5kg weight and 25×25mm cross-sectional area on both sides, and testing the material resistance between the two copper blocks.

[0070] The above data shows that the conductive ink provided by this technical solution has good adhesion and conductivity, as well as good conductive stability. Polydopamine coats the polyvinyl alcohol (PVA) fibers, which not only improves the surface activity of the PVA fibers, ensuring their overall stability and adhesion, but also conducts conductive modification on the PVA fibers, solving the insulation problem of PVA. Simultaneously, the PVA condensate and polydopamine modification form a conductive network structure, which not only effectively reduces the resistance value but also reduces local resistance variations, achieving uniform conductivity.

[0071] It is understood that the above detailed description of the present invention is for illustrative purposes only and is not intended to limit the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effects; as long as the usage requirements are met, they are all within the protection scope of the present invention.

Claims

1. A method for preparing a network-based high-adhesion conductive ink, characterized in that: The method includes the following steps: Step 1: Add dispersant, defoamer, pigment, and waterborne polyurethane to water and stir thoroughly to form a mixture; Step 2: Add conductive materials and fiber fillers to the mixture and stir rapidly for 20-30 minutes. Then add leveling agent and anti-settling agent and stir at a constant temperature to obtain high-adhesion conductive ink.

2. The method for preparing network-based high-adhesion conductive ink according to claim 1, characterized in that: The temperature for thorough stirring in step 1 is 20-30℃, and the stirring speed is 300-500 r / min.

3. The method for preparing network-based high-adhesion conductive ink according to claim 1, characterized in that: The rapid stirring in step 2 has a stirring speed of 400-600 r / min, and the constant temperature stirring has a temperature of 40-60℃ and a stirring speed of 300-500 r / min.

4. The method for preparing network-based high-adhesion conductive ink according to claim 1, characterized in that: The mass ratio of the high-adhesion conductive ink is as follows: 50-80 parts of water-based polyurethane, 10-15 parts of conductive material, 20-30 parts of fiber filler, 0.5-1 part of dispersant, 0.3-0.5 parts of defoamer, 1-2 parts of leveling agent, 0.5-1 part of anti-settling agent, 2-4 parts of pigment, and 60-100 parts of water.

5. The method for preparing network-based high-adhesion conductive ink according to claim 4, characterized in that: The solid content of the waterborne polyurethane is 30-40%.

6. The method for preparing network-based high-adhesion conductive ink according to claim 4, characterized in that: The conductive material is a porous polyvinyl alcohol condensate, and the conductive material is a hollow polyvinyl alcohol condensate with a porous structure.

7. The method for preparing network-based high-adhesion conductive ink according to claim 4, characterized in that: The fiber filler is polydopamine-modified polyvinyl alcohol fiber, and the polydopamine has a porous structure.

8. The method for preparing network-based high-adhesion conductive ink according to claim 4, characterized in that: The dispersant is zinc stearate; the defoamer is polydimethylsiloxane.

9. The method for preparing network-based high-adhesion conductive ink according to claim 4, characterized in that: The pigment used is one of Permanent Red F2R, Permanent Red F4R, Pigment Red 22, or Solid Red Blue Lotus.

10. The method for preparing network-based high-adhesion conductive ink according to claim 4, characterized in that: The leveling agent is polyether-modified polydimethylsiloxane; the anti-settling agent is ultrafine fumed silica with a particle size of 7-14 nm.

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