Preparation method of graphene ethyl cellulose conductive ink

Abstract

The invention relates to a preparation method of graphene ethyl cellulose conductive ink, and belongs to the technical field of conductive ink. Performing ultrasonic treatment on crystalline flake graphite, adding the crystalline flake graphite into a high-pressure reaction kettle, and after the reaction is finished, performing pressure relief and taking out to obtain graphene; the preparation method comprises the following steps: putting graphene, 3-(2, 3-epoxypropoxy) propyltrimethoxysilane and a solvent into a stirring kettle, vigorously stirring and reacting, adding 4-aminopyrrole-2-carboxylic acid and silver nitrate, and reacting; adding sodium ethoxide and allyl (cyclopentadienyl) nickel, and stirring for reaction to obtain a graphene solution; ethyl cellulose is added into a solvent, ultrasonic dispersion is carried out until ethyl cellulose is completely dissolved, and an ethyl cellulose solution is obtained; heating the graphene solution to boiling, adding the ethyl cellulose solution, uniformly stirring, carrying out ultrasonic treatment, cooling to room temperature, and adding an accelerant, a flatting agent, a defoaming agent, a coalescing agent and a curing agent to obtain graphene ethyl cellulose conductive ink; the graphene ethyl cellulose conductive ink prepared by the invention has excellent conductivity.

Description

Technical Field

[0001] This invention relates to the field of conductive ink technology, and in particular to a method for preparing a graphene ethyl cellulose conductive ink. Background Technology

[0002] Conductive inks for printing first appeared in the late 20th century. The rapid development of electronic technology, especially the innovation of silicon-based electronic circuits, has driven the development of conductive inks. The classification standards for conductive inks vary greatly depending on their application. If classified according to drying and curing methods, they are mainly divided into three types: low-temperature curing, high-temperature curing, and ultraviolet curing. If classified according to the properties of the conductive filler, they can be divided into metallic, carbon-based, and organic polymer-based types.

[0003] Chinese Patent CN110408267A discloses a graphene conductive ink, made from the following raw materials in parts by weight: 80-100 parts ink, 3-4.5 parts graphene, 1.1-1.4 parts leveling agent, 0.9-1.2 parts defoamer, 2.2-2.8 parts dispersant, and 12-18 parts co-solvent; wherein the graphene is nano-graphene flakes; and the thickness of the graphene is 1-10 nm. The graphene conductive ink of this invention, through careful selection of raw material composition and optimization of the content of each raw material, selects appropriate proportions of ink, graphene, leveling agent, defoamer, dispersant, and co-solvent.

[0004] Chinese Patent CN117143481A: This invention relates to a graphene conductive ink and its preparation method, comprising the following steps: shearing bulk graphite in a solvent to obtain graphite sheets; placing the graphite sheets in an alkane for ultrasonic treatment to assist graphene exfoliation into the oil phase; adding deionized water to the obtained mixture of graphene and alkane, ultrasonicating and shaking, and then allowing it to stand, repeating this process multiple times to obtain the graphene conductive ink.

[0005] Chinese Patent CN103319954A: Provides a graphene conductive ink, which is composed of the following components by weight percentage: graphene 0.001wt%~80wt%; binder 1wt%~60wt%; additives 0.1wt%~30wt%; the balance being solvent. This invention also provides a method for preparing the above-mentioned graphene conductive ink. The molecules of chemically doped graphene include one or more of polyaniline, polyacetylene, polythiophene, poly(p-phenylene), and polypyrrole. The functional groups of chemically modified graphene include one or more of aniline, pyrrole, imidazole, benzenesulfonic acid, thiophene, furanyl, phenyl, hydroxyl, ester, and their derivative groups.

[0006] The conductive inks prepared by the above patents and existing technologies have poor dispersibility and their conductivity needs to be further improved. Summary of the Invention

[0007] To address the above problems, this invention provides a method for preparing graphene ethyl cellulose conductive ink, the steps of which are as follows: S1: After sonicating flake graphite for 150-180 minutes, add it to a high-pressure reactor for reaction. After the reaction is completed, depressurize and remove the graphene to obtain graphene. S2: Place 100-200 parts graphene, 2-5 parts 3-(2,3-epoxypropoxy)propyltrimethoxysilane, and 1000-1200 parts solvent into a stirred tank and stir vigorously for 30-60 minutes. Then add 3-8 parts 4-aminopyrrole-2-carboxylic acid and 0.02-0.2 parts silver nitrate, and stir at 40-50℃ for 30-60 minutes. S3: Add 1-4 parts sodium ethoxide and 0.003-0.05 parts allyl (cyclopentadienyl) nickel CAS: 12107-46-9, stir at 60-70℃ for 50-100 minutes to obtain graphene solution; S4: Add 5-10 parts of ethyl cellulose to 30-50 parts of solvent and ultrasonically disperse until the ethyl cellulose is completely dissolved to obtain an ethyl cellulose solution; S5: Heat the graphene solution to boiling at 75-80℃, add the ethyl cellulose solution, stir evenly, then sonicate for 80-120 minutes. After cooling to room temperature, add 0.1-1 parts of accelerator, 0.1-1 parts of leveling agent, 0.1-1 parts of defoamer, 0.1-1 parts of film-forming aid, and 0.1-1 parts of curing agent to obtain graphene ethyl cellulose conductive ink.

[0008] The high-pressure reactor has a reaction temperature of 50-60℃, a reaction pressure of 10-14MPa, and a reaction time of 20-40min.

[0009] The solvent is one of water, methanol, ethanol, ethylene glycol, glycerol, terpineol, and acetone.

[0010] The accelerator is one of methylimidazole, 2-ethyl-4-methylimidazole, and 3-aminopropylimidazole.

[0011] The leveling agent is one of isophorone, diacetone alcohol, and Solvesso 150.

[0012] The defoamer mentioned is one of SY-3090 silicone defoamer, Y-2080 silicone defoamer, or BYK-018 silicone defoamer.

[0013] The film-forming aid is one of propylene glycol butyl ether, propylene glycol methyl ether acetate, and 12-ol ester.

[0014] The curing agent is one of dicyandiamide, polyamide, diethylenetriamine, ethylenediamine, diaminodiphenylmethane, diaminodiphenyl sulfone, phthalic anhydride, and maleic anhydride.

[0015] Reaction mechanism 1. Graphene exfoliation and processing: Natural flake graphite is exfoliated using supercritical carbon dioxide to obtain graphene with a complete surface morphology and fewer than four layers. This exfoliation method can effectively avoid the aggregation between graphene sheets and maintain its excellent conductivity.

[0016] The reaction of 4-aminopyrrole-2-carboxylic acid with silver nitrate produces a silver complex of 4-aminopyrrole-2-carboxylic acid; this step utilizes the coordination between silver ions and carboxylic acid groups to form a stable metal complex.

[0017] Glycidoxypropyl graphene undergoes an amino ring-opening reaction with a silver complex of 4-aminopyrrole-2-carboxylic acid, while allyl (cyclopentadienyl) nickel undergoes an amino-allyl addition reaction with the silver complex of 4-aminopyrrole-2-carboxylic acid. These two reactions introduce different functional groups, enhancing the chemical activity of the graphene surface and its compatibility with other materials.

[0018] 2. Preparation of graphene / ethyl cellulose conductive ink: Graphene prepared by supercritical method is used as conductive agent and ethyl cellulose is used as binder to prepare graphene / ethyl cellulose conductive ink; ethyl cellulose as binder not only provides good mechanical stability, but also promotes the uniform dispersion of graphene sheets in ink.

[0019] Technical effect The present invention provides a method for preparing graphene ethyl cellulose conductive ink. Compared with the prior art, the present invention has the following significant advantages: 1. Improved Conductivity: Graphene itself possesses excellent conductivity; its unique two-dimensional structure and high specific surface area make it an ideal conductive filler. In conductive inks, the conductive network formed between graphene sheets is the main pathway for current conduction. Allyl (cyclopentadienyl)nickel and silver 4-aminopyrrole-2-carboxylate complexes work together to optimize the dispersion of graphene in the ink, reducing agglomeration. This helps improve the conductivity of graphene conductive inks because good dispersion means a more uniform conductive network can be formed in the ink, thereby improving current conduction efficiency. Furthermore, this modification method may also endow graphene conductive inks with better mechanical properties and durability. 2. Flexibility and stability: Ethyl cellulose, as a binder, not only provides good mechanical stability but also endows the ink with a certain degree of flexibility; this enables graphene / ethyl cellulose conductive ink to form a stable conductive film layer on different substrates, making it suitable for flexible electronic devices and other fields.

[0020] 3. Process compatibility: The preparation process is compatible with existing printed electronics technology, which facilitates large-scale production and application; the excellent performance of graphene conductive ink makes it have broad application prospects in fields such as wireless radio frequency identification systems, smart packaging, and printed circuit boards. Attached Figure Description

[0021] Figure 1 This is a statistical chart of data from an example. Detailed Implementation

[0022] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description is provided in conjunction with embodiments and comparative examples: Sheet resistance test: The sheet resistance was measured using a four-probe resistance tester, and the test results are shown in Table 1.

[0023] Example 1 A method for preparing a graphene ethyl cellulose conductive ink, comprising the following steps: S1: After sonicating flake graphite for 150 minutes, add it to a high-pressure reactor for reaction. After the reaction is completed, depressurize and remove the graphene. S2: Place 100g graphene, 2g 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 1000g solvent into a stirred tank and stir vigorously for 30 minutes. Then add 3g 4-aminopyrrole-2-carboxylic acid and 0.02g silver nitrate and stir at 40℃ for 30 minutes. S3: Add 1g sodium ethoxide and 0.003g allyl (cyclopentadienyl) nickel CAS: 12107-46-9, stir at 60℃ for 50 minutes to obtain graphene solution; S4: Add 5g of ethyl cellulose to 30g of solvent and ultrasonically disperse until the ethyl cellulose is completely dissolved to obtain an ethyl cellulose solution; S5: Heat the graphene solution to boiling at 75°C, add the ethyl cellulose solution, stir evenly, then sonicate for 80 minutes. After cooling to room temperature, add 0.1g accelerator, 0.1g leveling agent, 0.1g defoamer, 0.1g film-forming aid, and 0.1g curing agent to obtain graphene ethyl cellulose conductive ink.

[0024] The high-pressure reactor has a reaction temperature of 50°C, a reaction pressure of 10 MPa, and a reaction time of 20 min.

[0025] The solvent is water.

[0026] The accelerator is methylimidazole.

[0027] The leveling agent is isophorone.

[0028] The defoamer mentioned is SY-3090 silicone defoamer.

[0029] The film-forming aid is propylene glycol butyl ether.

[0030] The curing agent is dicyandiamide.

[0031] Example 2 A method for preparing a graphene ethyl cellulose conductive ink, comprising the following steps: S1: After sonicating flake graphite for 160 minutes, it is added to a high-pressure reactor for reaction. After the reaction is completed, the pressure is released and the graphene is taken out to obtain graphene. S2: Place 140g graphene, 3g 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 1050g solvent into a stirred tank and stir vigorously for 40 minutes. Then add 5g 4-aminopyrrole-2-carboxylic acid and 0.1g silver nitrate and stir at 45℃ for 40 minutes. S3: Add 2g sodium ethoxide and 0.02g allyl (cyclopentadienyl) nickel CAS: 12107-46-9, stir at 65℃ for 70 minutes to obtain graphene solution; S4: Add 6g of ethyl cellulose to 35g of solvent and ultrasonically disperse until the ethyl cellulose is completely dissolved to obtain an ethyl cellulose solution; S5: Heat the graphene solution to boiling at 76℃, add the ethyl cellulose solution, stir evenly, then sonicate for 90 minutes. After cooling to room temperature, add 0.5g accelerator, 0.5g leveling agent, 0.5g defoamer, 0.5g film-forming aid, and 0.5g curing agent to obtain graphene ethyl cellulose conductive ink.

[0032] The high-pressure reactor has a reaction temperature of 55°C, a reaction pressure of 11 MPa, and a reaction time of 25 min.

[0033] The solvent is methanol.

[0034] The accelerator is 2-ethyl-4-methylimidazole.

[0035] The leveling agent is diacetone alcohol.

[0036] The defoamer mentioned is Y-2080 silicone defoamer.

[0037] The film-forming aid is propylene glycol methyl ether acetate.

[0038] The curing agent is diethylenetriamine.

[0039] Example 3 A method for preparing a graphene ethyl cellulose conductive ink, comprising the following steps: S1: After sonicating flake graphite for 170 minutes, it is added to a high-pressure reactor for reaction. After the reaction is completed, the pressure is released and the graphene is taken out to obtain graphene. S2: Place 180g graphene, 4g 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 1150g solvent into a stirred tank and stir vigorously for 50 minutes. Then add 7g 4-aminopyrrole-2-carboxylic acid and 0.15g silver nitrate and stir at 45℃ for 50 minutes. S3: Add 3g sodium ethoxide and 0.04g allyl (cyclopentadienyl) nickel CAS: 12107-46-9, stir at 65℃ for 90 minutes to obtain graphene solution; S4: Add 9g of ethyl cellulose to 45g of solvent and ultrasonically disperse until the ethyl cellulose is completely dissolved to obtain an ethyl cellulose solution; S5: Heat the graphene solution to boiling at 78°C, add the ethyl cellulose solution, stir evenly, then sonicate for 110 minutes. After cooling to room temperature, add 0.8g accelerator, 0.8g leveling agent, 0.8g defoamer, 0.8g film-forming aid, and 0.8g curing agent to obtain graphene ethyl cellulose conductive ink.

[0040] The high-pressure reactor has a reaction temperature of 55°C, a reaction pressure of 13 MPa, and a reaction time of 35 min.

[0041] The solvent is ethanol.

[0042] The accelerator is 2-ethyl-4-methylimidazole.

[0043] The leveling agent is diacetone alcohol.

[0044] The defoamer mentioned is Y-2080 silicone defoamer.

[0045] The film-forming aid is propylene glycol methyl ether acetate.

[0046] The curing agent is ethylenediamine.

[0047] Example 4 A method for preparing a graphene ethyl cellulose conductive ink, comprising the following steps: S1: After sonicating flake graphite for 180 minutes, add it to a high-pressure reactor for reaction. After the reaction is completed, depressurize and remove the graphene. S2: Place 200g graphene, 5g 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 1200g solvent into a stirred tank and stir vigorously for 60 minutes. Then add 8g 4-aminopyrrole-2-carboxylic acid and 0.2g silver nitrate and stir at 50℃ for 60 minutes. S3: Add 4g sodium ethoxide and 0.05g allyl (cyclopentadienyl) nickel CAS: 12107-46-9, stir at 70℃ for 100 minutes to obtain graphene solution; S4: Add 10g of ethyl cellulose to 50g of solvent and ultrasonically disperse until the ethyl cellulose is completely dissolved to obtain an ethyl cellulose solution; S5: Heat the graphene solution to boiling at 80℃, add the ethyl cellulose solution, stir evenly, then sonicate for 120 minutes, cool to room temperature, and add 1g accelerator, 1g leveling agent, 1g defoamer, 1g film-forming aid, and 1g curing agent to obtain graphene ethyl cellulose conductive ink.

[0048] The high-pressure reactor has a reaction temperature of 60℃, a reaction pressure of 14MPa, and a reaction time of 40min.

[0049] The solvent is terpineol.

[0050] The promoter is 3-aminopropylimidazolium.

[0051] The leveling agent mentioned is Solvesso 150.

[0052] The defoamer mentioned is BYK-018 silicone defoamer.

[0053] The film-forming aid is 12-ol ester.

[0054] The curing agent is maleic anhydride.

[0055] Comparative Example 1 The same as in Example 1 was used, but without the addition of 4-aminopyrrole-2-carboxylic acid and allyl (cyclopentadienyl) nickel.

[0056] Comparative Example 2 The same as in Example 1 was used, but without the addition of 4-aminopyrrole-2-carboxylic acid.

[0057] Comparative Example 3 Allyl (cyclopentadienyl) nickel was not added; otherwise, it was the same as in Example 1.

[0058] Table 1 Based on the data analysis of the above embodiments and comparative examples, the graphene ethyl cellulose conductive ink prepared by the present invention has excellent conductivity.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing a graphene ethyl cellulose conductive ink, comprising the following steps: S1: After sonicating flake graphite for 150-180 minutes, add it to a high-pressure reactor for reaction. After the reaction is completed, depressurize and remove the graphene to obtain graphene. S2: Place 100-200 parts graphene, 2-5 parts 3-(2,3-epoxypropoxy)propyltrimethoxysilane, and 1000-1200 parts solvent into a stirred tank and stir vigorously for 30-60 minutes. Then add 3-8 parts 4-aminopyrrole-2-carboxylic acid and 0.02-0.2 parts silver nitrate, and stir at 40-50℃ for 30-60 minutes. S3: Add 1-4 parts sodium ethoxide and 0.003-0.05 parts allyl (cyclopentadienyl) nickel, and stir at 60-70℃ for 50-100 minutes to obtain a graphene solution; S4: Add 5-10 parts of ethyl cellulose to 30-50 parts of solvent and ultrasonically disperse until the ethyl cellulose is completely dissolved to obtain an ethyl cellulose solution; S5: Heat the graphene solution to boiling at 75-80℃, add the ethyl cellulose solution, stir evenly, then sonicate for 80-120 minutes. After cooling to room temperature, add 0.1-1 parts of accelerator, 0.1-1 parts of leveling agent, 0.1-1 parts of defoamer, 0.1-1 parts of film-forming aid, and 0.1-1 parts of curing agent to obtain graphene ethyl cellulose conductive ink.

2. The method for preparing a graphene ethyl cellulose conductive ink according to claim 1, characterized in that: The high-pressure reactor has a reaction temperature of 50-60℃, a reaction pressure of 10-14MPa, and a reaction time of 20-40min.

3. The method for preparing a graphene ethyl cellulose conductive ink according to claim 1, characterized in that: The solvent is one of water, methanol, ethanol, ethylene glycol, glycerol, terpineol, and acetone.

4. The method for preparing a graphene ethyl cellulose conductive ink according to claim 1, characterized in that: The accelerator is one of methylimidazole, 2-ethyl-4-methylimidazole, and 3-aminopropylimidazole.

5. The method for preparing a graphene ethyl cellulose conductive ink according to claim 1, characterized in that: The leveling agent is one of isophorone, diacetone alcohol, and Solvesso 150.

6. The method for preparing a graphene ethyl cellulose conductive ink according to claim 1, characterized in that: The defoamer mentioned is one of SY-3090 silicone defoamer, Y-2080 silicone defoamer, or BYK-018 silicone defoamer.

7. The method for preparing a graphene ethyl cellulose conductive ink according to claim 1, characterized in that: The film-forming aid is one of propylene glycol butyl ether, propylene glycol methyl ether acetate, and 12-ol ester.

8. The method for preparing a graphene ethyl cellulose conductive ink according to claim 1, characterized in that: The curing agent is one of dicyandiamide, polyamide, diethylenetriamine, ethylenediamine, diaminodiphenylmethane, diaminodiphenyl sulfone, phthalic anhydride, and maleic anhydride.

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