Resistance paste suitable for flexible printing electronic technology and preparation method thereof

Abstract

The invention discloses a resistance paste suitable for a flexible printing electronic technology and a preparation method thereof, the paste is composed of the following components: 20%-50% of a functional conductive phase which is a compound mixture of conductive carbon black, graphene nanosheets and ruthenium dioxide nanoparticles; 15%-33% of a modified resin binding phase; 25%-45% of a reactive diluent and a solvent; and 2%-5% of an auxiliary agent. The preparation method comprises the following steps: pre-dispersing, grinding, mixing, defoaming, filtering and the like. Through the ternary compound conductive phase and the UV curing system, the resistance paste with wide sheet resistance range, excellent environmental durability and good flexographic printing adaptability is successfully obtained. The paste can be directly printed on a flexible base material to form a high-performance resistor body, can replace a traditional chip resistor, is particularly suitable for large-scale manufacturing of printed circuits, and can remarkably save labor and material cost and improve production efficiency and circuit reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic functional materials, in particular to a resistance paste suitable for flexible printed electronics technology and a preparation method thereof, which can be used to print and prepare high-performance and high-reliability resistors on flexible substrates such as PET, PI and TPU. BACKGROUND

[0002] With the rapid development of electronic devices towards lightweight, flexibility and integration, flexible printed electronics technology has been widely used in smart wear, flexible display, automotive electronics and other fields due to its advantages of realizing high-precision and large-scale circuit printing on flexible substrates (such as PET and PI films). As a core component of the circuit, the preparation method and performance of the resistance element directly affect the reliability and production efficiency of flexible electronic devices.

[0003] In the current flexible electronic circuit, the assembly of resistance elements mainly adopts the "manual resistance sheet mounting" method, that is, independent sheet resistance is welded on the surface of the flexible circuit board (FPC) or rigid circuit board (PCB) through the SMT patch process. Although this process can meet the basic resistance function requirements, it has the following key problems in actual production and application: (1) low production efficiency and high labor cost: manual resistance sheet mounting needs to go through many processes such as component sorting, positioning alignment, welding and curing, and dozens to hundreds of resistance sheets need to be mounted on each circuit board, and the resistance mounting time of a single circuit board is as long as 5-10 minutes; at the same time, manual operation is easy to cause resistance mounting misalignment, missing welding due to fatigue, misjudgment and other factors, with a high defect rate of 2%-5%, further increasing the production cost; (2) low circuit integration and poor reliability: the connection between the resistance sheet and the circuit board depends on the welding point, and in the long-term start-stop or vibration environment, the welding point is easy to oxidize and fall off, leading to resistance failure and shortening the service life of the circuit; (3) poor process compatibility and difficult to adapt to flexible substrates: the traditional SMT patch process is more suitable for rigid PCB substrates, and high-temperature welding (welding temperature 220-260℃) in the patching process is easy to cause the shrinkage and deformation of flexible substrates, damaging the circuit structure; at the same time, the mounted resistance sheet is a rigid element, which has poor deformation compatibility with the flexible substrate, and the resistance sheet is easy to fall off under stress, which cannot meet the use scene requirements of flexible electronic devices.

[0004] To solve the above problems, the industry attempts to directly prepare resistance elements by printing, that is, to replace the traditional independent resistance sheet by printing a resistance layer on the substrate using conductive paste. The existing printed resistance paste is mainly divided into high-temperature curing type (curing temperature 150-200℃) and normal temperature drying type. However, the fineness of the existing printed resistance paste is usually 8-12μm, while the fineness requirement of flexible printed electronic technology (such as flexo printing and screen printing) is ≤5μm. The coarse particle paste is easy to block the printing screen roller or screen plate, resulting in uneven printing thickness of the resistance layer (deviation ±2μm or more), which further aggravates the resistance value fluctuation. At the same time, the thixotropy and leveling property of the existing paste are difficult to balance. Too strong thixotropy will cause "wire drawing" phenomenon during printing, and too weak thixotropy will cause the wet film to flow too much on the flexible substrate, which cannot accurately control the width-length ratio of the resistance layer (the resistance value is proportional to the width-length ratio), and it is difficult to accurately prepare different resistance values in the printed circuit.

[0005] Therefore, it has become a technical problem to be solved in the current industry to develop a resistance paste that is suitable for flexible printed electronic technology, can be directly printed on a flexible substrate, has high resistance precision and stability, and can replace manual resistance sheet installation to reduce the manufacturing cost of printed circuits. SUMMARY

[0006] (I) Invention purpose The present application aims to solve the problems of low efficiency, high cost and poor reliability of traditional manual resistance sheet installation in printed circuits, and the problem that the existing printed resistance paste cannot adapt to flexible printed electronic technology, and provides a resistance paste that can be directly prepared by flexible printing, has high resistance precision and stability, and can reduce the manufacturing cost of circuits, and a preparation method thereof.

[0007] (II) Technical solution To achieve the above purpose, the present application provides a resistance paste suitable for flexible printed electronic technology, which is characterized by accurately controlling the selection and ratio of each component to balance the printing adaptability, curing efficiency and resistance layer performance of the paste. The specific technical solution is as follows: consists of the following components by mass percentage: Functional conductive phase: 20%-50%, which is a compounded mixture of conductive carbon black (CB), graphene nanoplatelets (GNPs) and ruthenium dioxide (RuO2) nanoparticles, with a mass ratio of (1-3):(1-3):(2-4). Among them, the conductive carbon black selects high specific surface area acetylene carbon black with a specific surface area of 800-1200m² / g, the graphene nanoplatelets have a sheet thickness of <5nm and a lateral size of 5-20μm, and the ruthenium dioxide nanoparticles have a particle size of <100nm. The three are compounded to build a continuous and stable conductive network, while balancing the conductivity and cost. Modified resin binder phase: 15%-33%, using ultraviolet light curing modified acrylic resin, selecting a type with a number average molecular weight <5000 and a functionality of 6, which has strong adhesion to flexible substrates PET and PI, and the resin layer formed after curing has good flexibility. Active diluent and solvent: 25%-45%, the active diluent is an aliphatic acrylate monomer, with a mass fraction of 10%-27%; the solvent is a low-boiling alcohol ether solvent, propylene glycol methyl ether, with a boiling point of 120-130°C and a mass fraction of 12%-18%. The active diluent can adjust the viscosity of the slurry and participate in the curing reaction, and the solvent is used to assist dispersion and control the drying speed of the wet film to avoid plate blocking during printing. Auxiliary agents: 2%-5%, including dispersants, leveling agents, ultraviolet light initiators, and thixotropic agents. Among them, the dispersant is BYK-163, with a mass fraction of 0.8%-2%, used to prevent the agglomeration of conductive powder; the leveling agent is BYK-331, with a mass fraction of 0.2%-0.5%, used to improve the printing leveling property of the slurry; the ultraviolet light initiator is TPO-L, with a mass fraction of 0.8%-2%, suitable for 365nm ultraviolet wavelength, ensuring rapid curing; the thixotropic agent is hydrophobic fumed SiO2, with a mass fraction of 0.2%-1%, used to balance the thixotropy and leveling property of the slurry, avoiding printing stringing or uneven wet film.

[0008] Method for preparing resistive slurry This method precisely controls the fineness and uniformity of the slurry through the four-step process of "pre-dispersion-grinding-mixing-deaeration filtration", and the specific steps are as follows: Step a: pre-dispersion According to the proportion, the functional conductive phase, 50%-60% of the active diluent, all dispersants, and 40%-50% of the solvent are weighed and added to a high-speed disperser, stirred at a speed of 2000-3000r / min for 15-20 minutes. Before stirring, mix the solvent and dispersant for 5 minutes, then add the conductive carbon black, graphene nanosheet, and ruthenium dioxide nanoparticles one by one, with an interval of 3 minutes between each addition to avoid hard lumps formed by dry powder agglomeration, to obtain a preliminary dispersed mixture. Step b: grinding Transfer the mixture obtained in step a to a three-roll mill, adjust the roll spacing, the first pass is 50-80μm, the second pass is 20-30μm, and the third pass is 10-20μm, pass cooling water, water temperature is 20-25℃, control the grinding temperature ≤40℃, grind 3-5 times. After each grinding, use a doctor fineness gauge to detect the fineness of the slurry to ensure that the final fineness is ≤5μm and the particle size distribution D50 is <3μm, to obtain a uniform conductive phase slurry. Step c: mixing The modified resin binder phase, the remaining active diluent and solvent, the leveling agent, the ultraviolet light initiator and the thixotropic agent are added to the conductive phase slurry and transferred to a vacuum stirring tank. The stirring speed is 600-1000 r / min and the stirring time is 20-40 min under a vacuum degree of-0.08 MPa to-0.1 MPa to ensure that the components are uniformly mixed and air bubbles are avoided. Step d: defoaming and filtering The vacuum degree of the vacuum stirring tank is maintained, and the defoaming is continued for 15-30 min until there are no obvious air bubbles in the slurry. Then, the slurry is filtered through a 150-300 mesh nylon filter screen to remove coarse particles that are not ground completely, and the final resistance slurry is obtained.

[0009] The present application has the following advantages: The artificial installation is replaced, the cost is reduced and the efficiency is improved. The stable resistance body can be directly printed, and the SMT installation process is omitted, so that the labor cost, material management cost and equipment energy consumption in the flexible printed circuit manufacturing are greatly saved, and the production efficiency is significantly improved.

[0010] The comprehensive electrical performance is excellent. Through the ternary composite conductive phase system of CB / GNPs / RuO2, the sheet resistance of the single slurry is covered in a wide range from 100 mΩ / □ to 10 MΩ / □, and the absolute value of the average resistance temperature coefficient (TCR) is less than ±150 ppm / ℃, which meets the application requirements and high stability requirements of various resistances in flexible printed circuits.

[0011] The flexible printing is adapted and the mass production is compatible. The slurry viscosity is controlled in the range of 500-1500 mPa·s, the thixotropy and leveling property are balanced, the flexible printing equipment such as flexographic printing and screen printing can be used for mass production, the UV curing time is only 3-5 seconds, which is synchronized with the printing speed, the daily production capacity of a single production line can reach more than 10,000 pieces, and the industrial mass production demand is adapted. Specific embodiments

[0012] The present application will be further described in detail through specific embodiments, but it should not be understood that the scope of the present application is limited to the following examples. Various substitutions or changes made according to ordinary technical knowledge and conventional means in the art without departing from the above-mentioned method idea of the present application should be included in the scope of the present application. Examples

[0013] 1. Resistance slurry components (100 g in total) Functional conductive phase: conductive carbon black (10 g), graphene nanosheet (10 g), and ruthenium dioxide nanoparticles (15 g), total 35 g (mass ratio 35%); Modified resin binder phase: ultraviolet light curing modified acrylic resin 22 g (mass ratio 22%); Active diluent and solvent: aliphatic acrylate monomer (22.8 g), propylene glycol methyl ether (15.2 g), total 38 g (mass ratio 38%); Auxiliary: BYK-163 (1.5 g), BYK-331 (0.5 g), TPO-L (2 g), fumed SiO2 (1 g), total 5 g (mass ratio 5%). 2. Preparation process Pre-dispersion: propylene glycol methyl ether (6.08 g, 40% solvent) and BYK-163 (1.5 g) were added to a high-speed disperser and stirred for 5 minutes; then conductive carbon black (10 g), graphene nanosheet (10 g), and ruthenium dioxide nanoparticles (15 g) were added in sequence, with a 3-minute interval between each step; aliphatic acrylate monomer (13.68 g, 60% active diluent) was then added, and the mixture was stirred at 2500 r / min for 18 minutes to obtain a preliminary mixture. Grinding: the preliminary mixture was fed into a three-roll mill, with the roll gap set to 60 μm, 25 μm, and 15 μm in sequence, and the cooling water temperature was 22°C. The mixture was ground for 4 passes, and the fineness was detected to be 3.5 μm. The conductive phase slurry was obtained. Mixing: the conductive phase slurry was added with ultraviolet light curing modified acrylic resin (22 g), the remaining aliphatic acrylate monomer (9.12 g), the remaining propylene glycol methyl ether (9.12 g), BYK-331 (0.5 g), TPO-L (2 g), and fumed SiO2 (1 g). The mixture was stirred at 800 r / min for 30 minutes under a vacuum degree of -0.09 MPa. Defoaming and filtration: the mixture was defoamed for 20 minutes under the same vacuum degree, and then filtered through a 200-mesh nylon filter to obtain the final resistive paste. 3. Performance test The paste was printed on a 125 μm PET film through a flexographic printer with a 350-line / inch screen roller at a printing speed of 15 m / min and a squeegee pressure of 0.15 MPa. The resistive film had a size of 10 mm x 5 mm and a thickness of 8 μm. Then, the film was cured using a 365 nm UV curing machine at a dose of 500 mJ / cm². The performance of the resistive layer was tested as follows: Resistance value: 49 Ω (design value 50 Ω, deviation 2.0%); Adhesion: 0 grade (no peeling) by cross-hatch method; Temperature resistance: resistance value drift rate of 3.2% after 50 cycles between -40°C and 85°C; Moisture resistance: resistance value drift rate of 5.2% after 1000 hours at 85°C / 85% RH; Flexibility: resistance value change rate of 2.3% after 1000 bending cycles with a bending radius of 5 mm. Example

[0014] 1. Resistive paste components (total mass 100 g) Functional conductive phase: conductive carbon black (12.5 g), graphene nanosheet (12.5 g), ruthenium dioxide nanoparticles (25 g), total 50 g (mass ratio 50%); Modified resin binder phase: ultraviolet light curing modified acrylic resin 15 g (mass ratio 15%); Active diluent and solvent: aliphatic acrylate monomer (18 g), propylene glycol methyl ether (12 g), total 30 g (mass ratio 30%); Auxiliary agent: BYK-163 (2 g), BYK-331 (0.5 g), TPO-L (2 g), fumed SiO2 (0.5 g), total 5 g (mass ratio 5%). 2. Preparation process Pre-dispersion: propylene glycol methyl ether (4.8 g, 40% solvent) and BYK-163 (2 g) were added to a high-speed disperser and stirred for 5 minutes; then conductive carbon black (12.5 g), graphene nanosheet (12.5 g), and ruthenium dioxide nanoparticles (25 g) were added in sequence, with a 3-minute interval between each step; aliphatic acrylate monomer (10.8 g, 60% active diluent) was then added, and stirring was carried out at 2600 r / min for 20 minutes to obtain a preliminary mixture. Grinding: the preliminary mixture was sent to a three-roll mill, with the roll gap set at 65 μm, 28 μm, and 12 μm in sequence, the cooling water temperature was 22 ℃, and the grinding was carried out for 4 times. The fineness was detected to be 3.0 μm, and a conductive phase slurry was obtained. Mixing: ultraviolet light curing modified acrylic resin (15 g), remaining aliphatic acrylate monomer (7.2 g), remaining propylene glycol methyl ether (7.2 g), BYK-331 (0.5 g), TPO-L (2 g), and fumed SiO2 (0.5 g) were added to the conductive phase slurry, and stirring was carried out at 900 r / min for 35 minutes under a vacuum degree of -0.095 MPa. Defoaming and filtering: defoaming was carried out under the same vacuum degree for 25 minutes, and the final resistance paste was obtained by filtering with a 200-mesh nylon filter.

[0015] 3. Performance test The paste was printed on a 125 μm PET film by a flexographic printing machine with a 350-line / inch screen roller at a printing speed of 15 m / min and a squeegee pressure of 0.15 MPa, and the resistance film size was 10 mm x 5 mm with a thickness of 8 μm. Then, the performance of the resistance layer was tested after curing with a 365 nm UV curing machine at 500 mJ / cm². Resistance value: 9.8 Ω (design value 10 Ω, deviation 0.2%); Adhesion: 0 grade by cross-hatch method; Temperature cycle resistance (-40 ℃-85 ℃, 50 times) resistance drift rate 4.5%; Humidity resistance (85°C / 85%RH, 1000h) resistance drift rate 5.8%.

[0016] Flexibility: bending radius 5mm, bending 1000 times, resistance value change rate 3.1%. Example

[0017] 1. Resistance paste components (total mass 100g) Functional conductive phase: conductive carbon black (10.5g), graphene nanosheet (10.5g), ruthenium dioxide nanoparticles (21g), total 30g (mass ratio 42%); Modified resin binder phase: ultraviolet light curing modified acrylic resin 30g (mass ratio 30%); Active diluent and solvent: aliphatic acrylate monomer (10g), propylene glycol methyl ether (15g), total 25g (mass ratio 25%); Auxiliary agent: BYK-163 (1.3g), BYK-331 (0.4g), TPO-L (1g), hydrophobic fumed SiO2 (0.3g), total 3g (mass ratio 3%). 2. Preparation process Pre-dispersion: add propylene glycol methyl ether (4g, 40% solvent) and BYK-163 (1.3g) to a high-speed disperser and stir for 5 minutes; add conductive carbon black (9g), graphene nanosheet (9g), and ruthenium dioxide nanoparticles (12g) in sequence, with a 3-minute interval between each step; then add aliphatic acrylate monomer (9g, 60% active diluent) and stir at 2800r / min for 20 minutes to obtain a preliminary mixture. Grinding: set the three-roll mill roller spacing to 70μm, 30μm, and 18μm, the cooling water temperature to 23°C, and grind for 5 passes; the fineness is detected to be 4.2μm, D50=2.8μm, and the conductive phase paste is obtained.

[0018] Mixing: add ultraviolet light curing modified acrylic resin (30g), remaining aliphatic acrylate monomer (6g), remaining propylene glycol methyl ether (6g), BYK-331 (0.4g), TPO-L (1g), and fumed SiO2 (0.3g) to the conductive phase paste, and stir at 900r / min for 35 minutes under a vacuum degree of -0.095MPa. Defoaming and filtering: defoam under vacuum for 25 minutes and filter with a 250-mesh nylon filter screen to obtain the final paste. 3. Performance test Print the paste through a flexographic printing machine with a 400-line / inch screen roller at a printing speed of 12m / min, and test the resistance film with a size of 10mm×5mm and a thickness of 9μm after curing by a 365nm UV curing machine at 500mJ / cm². The results are as follows: Resistance: 79.6Ω (design value 80Ω, deviation 0.5%); Adhesion: 0 grade (no peeling) by crosshatch method; Temperature cycle resistance (-40℃-85℃, 50 times): resistance drift rate 2.8%; Moisture resistance (85℃ / 85%RH, 1000h): resistance drift rate 4.3%; Flexibility: bending radius 5mm, bending 1000 times, resistance change rate 3.5%. Example

[0019] 1. Resistance paste components (total mass 100g) Functional conductive phase: conductive carbon black (5.7g), graphene nanosheet (5.7g), ruthenium dioxide nanoparticles (8.6g), total 20g (mass ratio 20%); Modified resin binder phase: ultraviolet light curing modified acrylic resin 33g (mass ratio 33%); Active diluent and solvent: aliphatic acrylate monomer (27g), propylene glycol methyl ether (18g), total 45g (mass ratio 45%); Auxiliary agent: BYK-163 (0.8g), BYK-331 (0.2g), TPO-L (0.8g), fumed SiO2 (0.2g), total 2g (mass ratio 2%). 2. Preparation process Pre-dispersion: propylene glycol methyl ether (7.2g, 40% solvent) and BYK-163 (0.8g) were stirred for 5 minutes, and then conductive carbon black (5.7g), GNPs (5.7g), RuO2 (8.6g) were added in sequence, and aliphatic acrylate monomer (16.2g, 60% diluent) was added, and stirred at 2500r / min for 18 minutes.

[0020] Grinding: three-roll mill roller spacing 60μm, 25μm, 15μm, cooling water 22℃, grinding 4 times, fineness 4.8μm, D50=3.2μm. Mixing: ultraviolet light curing modified acrylic resin (33g), remaining aliphatic acrylate monomer (10.8g), remaining propylene glycol methyl ether (10.8g), BYK-331 (0.2g), TPO-L (0.8g), fumed SiO2 (0.2g) were added to the conductive phase slurry, and stirred at 700r / min for 25 minutes under a vacuum degree of -0.08MPa. Defoaming and filtering: vacuum defoaming for 20 minutes, 180 mesh nylon filter screen filtering, to obtain the slurry.

[0021] 3. Performance test The paste was printed by a flexo printer 300 line / inch anilox roll at a printing speed of 10 m / min, and the resistance film had a size of 10 mm x 5 mm and a thickness of 10 μm. After UV curing, the results were as follows: Resistance value: 155 Ω (design value 150 Ω, deviation 3.3%); Adhesion: 0 grade by cross-hatch method; Temperature cycle drift rate: 5.2%; Moisture drift rate: 8.5%; Flexibility: bending radius 6 mm, bending 1000 times, resistance change rate 4.8%.

[0022] Comparative Example In order to highlight the advantages of the present application, a high-temperature curing paste commonly used in the industry was selected, and a comparative test was conducted on the "high-temperature curing epoxy resin-based paste" in the background art, as follows: 1. Paste components (total mass 100 g) Conductive phase: conductive carbon black (10 g), tin dioxide nanoparticles (15 g), total 25 g (no GNPs, traditional single conductive system); Binding phase: bisphenol A epoxy resin (30 g), amine curing agent (5 g), total 35 g; Solvent: dimethylbenzene (35 g), high-boiling-point solvent, boiling point 138℃; Auxiliary agent: dispersant BYK-110 (3 g), leveling agent BYK-306 (2 g), total 5 g.

[0023] 2. Preparation and application method Preparation: mix the conductive phase with 50% solvent and dispersant, stir at 1500 r / min for 30 minutes, grind in a ball mill with zirconium beads of 1 mm in diameter for 60 minutes, and a fineness of 8 μm; add the resin, curing agent, remaining solvent, and leveling agent, and stir at 800 r / min for 20 minutes without vacuum degassing.

[0024] 3. Performance test Screen printing (unable to flexo print due to poor thixotropy of the paste) on a 125 μm PET film, resistance film size 10 mm x 5 mm, thickness 10 μm; test after high-temperature curing in a 180℃ oven for 45 minutes, results as follows: Resistance value: 216.4 Ω (design value 200 Ω, deviation 8.2%); Adhesion: 1 grade by cross-hatch method; Temperature cycle drift rate: 12.5%; Moisture drift rate: 9.8%; Flexibility: bending radius 6 mm, bending 1000 times, resistance change rate 25%.

[0025]

[0026]

[0027] From the above table, the resistance paste of the application is superior to the prior art in curing efficiency, substrate adaptability, resistance precision, printing adaptability and the like, and can fully meet the application requirements of flexible printed electronic technology in printed circuits.

[0028] The above examples are the preferred embodiments of the application, but the embodiments of the application are not limited by the above examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the application should be equivalent replacement methods, and are all included in the protection scope of the application.

Claims

1. A resistive paste suitable for flexible printed electronics technology, characterized in that, consists of the following components by mass percentage: a functional conductive phase 20%-50%, which is a compounded mixture of conductive carbon black, graphene nanosheet and ruthenium dioxide nanoparticles; a modified resin binder phase 15%-33%, which is an ultraviolet light cured modified acrylic resin; an active diluent and a solvent 25%-45%; an auxiliary agent 2%-5%.

2. The resistive paste suitable for flexible printed electronics according to claim 1, characterized in that, In the functional conductive phase, the mass percentage of conductive carbon black, graphene nanosheet and ruthenium dioxide nanoparticles is (1-3):(1-3):(2-4).

3. The resistive paste suitable for flexible printed electronics technology according to claim 1, characterized in that, The active diluent is an aliphatic acrylate monomer, with a mass percentage of 10%-27%; the solvent is a low-boiling alcohol ether solvent, propylene glycol methyl ether, with a boiling point of 120-130℃, and a mass percentage of 12%-18%.

4. The resistive paste suitable for flexible printed electronics technology according to claim 1, characterized in that, The auxiliary agent includes a dispersant, a leveling agent, an ultraviolet light initiator and a thixotropic agent; the dispersant is BYK-163, with a mass percentage of 0.8%-2%; the leveling agent is BYK-331, with a mass percentage of 0.2%-0.5%; the ultraviolet light initiator is TPO-L, with a mass percentage of 0.8%-2%; and the thixotropic agent is hydrophobic fumed SiO2, with a mass percentage of 0.2%-1%.

5. A method for the preparation of a resistive paste suitable for flexible printed electronics technology, characterized by, The method comprises the following steps: a) pre-dispersion: mix the conductive functional phase with part of the active diluent, all of the dispersant and part of the solvent, and perform high-speed stirring pre-dispersion; b) grinding: grind the mixture obtained in step a) until the fineness is ≤5μm, to obtain a uniform conductive phase slurry; c) mixing: mix the conductive phase slurry obtained in step b) with the modified resin binder phase, the remaining active diluent and solvent, and other auxiliary agents, and stir under vacuum until uniform; d) degassing and filtering: degas and filter the slurry obtained in step c) under vacuum to obtain the final product.

6. A process for the preparation of a resistive paste suitable for flexible printed electronics according to claim 5, characterized in that, The grinding in step b) uses a three-roll mill, and is performed for 3-5 passes.

7. A process for the preparation of a resistive paste suitable for flexible printed electronics according to claim 5, characterized in that, The stirring in step c) is performed under vacuum; the vacuum degree of the vacuum condition is -0.08MPa to -0.1MPa, the stirring speed is 600-1000r / min, and the stirring time is 20-40 minutes.

8. A process for the preparation of a resistive paste suitable for flexible printed electronics according to claim 5, characterized in that, The filtering in step d) uses a 150-300 mesh filter screen, and the vacuum degassing time is 15-30 minutes.

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