A method for preparing conductive ink

Abstract

The present invention relates to the technical field of ink preparation, and more particularly to a method for preparing conductive ink. The present invention involves subjecting methylallyl tri-n-butyltin to an aminodi(methylenephosphonic acid) / Ag complex to an amino-ene addition reaction to form a corresponding addition product, which then undergoes a thiol-ene addition reaction with thiol-modified graphene. Finally, an amino-thiol addition reaction occurs to obtain a silver / tin composite hybrid graphene material. Through these reactions, silver particles are grown between graphene sheets, enhancing the conductivity of the ink while also preventing the stacking of graphene sheets. The silver / tin composite hybrid graphene material prepared by the present invention is more suitable for the preparation of conductive ink than pure graphene. The production cost of the conductive ink can be reduced, and its weight can also be significantly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of ink preparation, in particular to a method for preparing conductive ink. Background Art

[0002] Conductive ink, commonly known as paste ink, is a paste made by dispersing conductive materials (gold, silver, copper, and carbon) in a binder. It exhibits a certain degree of conductivity and can be used to print conductive dots or circuits. Gold-based, silver-based, copper-based, and carbon-based conductive inks have reached practical use and are used in printed circuits, electrodes, electroplating substrates, keyboard contacts, printed resistors, and other materials.

[0003] Chinese patent CN111889694B discloses a method for synthesizing one-dimensional silver nanomaterials, specifically comprising: dispersing fibers in an ethylene glycol solution to form solution A; dissolving silver nitrate and polyvinylpyrrolidone (PVP) in solution A to form solution B; and dissolving a halide in an aqueous solution to form solution C. After stirring solution B uniformly, solution C is added to obtain a mixed solution, which is stirred until the solution changes color to a dark reddish-brown. The solution is then temperature-controlled to 100-180°C and magnetically stirred at this constant temperature to obtain a one-dimensional silver nanomaterial mother solution. The resulting one-dimensional silver nanomaterial mother solution is then centrifuged and washed with anhydrous ethanol, and the resulting precipitate is dispersed in anhydrous ethanol to obtain a one-dimensional silver nanomaterial. The present invention combines the template method with the alcohol-heat method, introducing fibers as a deposition template for silver nanoparticles and inducing their growth into a one-dimensional morphology, enabling the rapid and simple synthesis of one-dimensional silver nanomaterials.

[0004] Chinese patent CN113480889B: discloses a graphene-based conductive ink, the components of which, by mass percentage, include: 30-60 wt% modified matrix resin, 30-60 wt% carbon-based composite filler, 1-8 wt% additive, and 1-10 wt% solvent. The modified matrix resin includes a matrix resin and high-imino melamine formaldehyde, and the carbon-based composite filler includes graphene.

[0005] Chinese Patent CN116023824B: Belonging to the field of ink technology, it discloses a conductive ink, its preparation method, and application. The conductive ink comprises composite particles having a core-shell structure consisting of a core and a shell; the core comprises a transition metal mixture, the transition metal mixture comprising a liquid metal and a filler; the liquid metal contains gallium; the filler comprises at least one of a metal, a metal oxide, or a perovskite, and the metal does not comprise liquid metal; the shell comprises, from the inside to the outside, a first shell and a second shell; the first shell comprises gallium oxide; the second shell comprises a polymer. When the conductive pattern formed by the conductive ink breaks after multiple stretching-rebound cycles, the transition metal mixture present at the crack can still form a conductive path due to its semi-fluid state and low surface energy, and can still adhere to the substrate, thereby maintaining the electrical connectivity of the conductive pattern, i.e., it has good fatigue resistance, for example, the number of stretching-rebound cycles is not less than 100,000.

[0006] The conductive inks prepared by the above patents and prior art have disadvantages such as high production cost, poor stability, and high resistivity. Summary of the Invention

[0007] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a method for preparing conductive ink. The silver / tin composite hybrid graphene material prepared by this method is more suitable for the preparation of conductive ink than pure graphene; it can reduce the production cost of conductive ink and significantly reduce its weight.

[0008] To achieve the above object, the present invention provides the following technical solution: a method for preparing a conductive ink, the operating steps of which are as follows:

[0009] A1: Weigh 10-15 parts of water-based acrylic resin, 1-5 parts of propylene glycol, 0.1-1 parts of leveling agent, 0.1-0.3 parts of pH adjuster, 40-50 parts of silver / tin composite hybrid graphene material, 0.1-0.5 parts of defoaming agent, and 24-40 parts of deionized water, and mix and stir for 20-40 minutes.

[0010] A2: Slowly add 0.5-1.5 parts of thickener and continue stirring for 20-40 minutes to obtain conductive ink.

[0011] In the present invention, the leveling agent is one of German Digo leveling agent 100, 410, 411, 415, 435, 432, 440, 450, 482, B1484, 300, and 370.

[0012] In the present invention, the pH regulator is one of citric acid, lactic acid, tartaric acid, malic acid and metatartaric acid.

[0013] In the present invention, the defoaming agent is a polyether defoaming agent.

[0014] In the present invention, the thickener is a polyurethane thickener.

[0015] In the present invention, the preparation method of the silver / tin composite hybrid graphene material is:

[0016] B1: Weigh 20-40 parts of aminobis(methylenephosphonic acid), 17-34 parts of AgNO3, and 2000-3000 parts of N-methylpyrrolidone by weight, add them to a reaction kettle, and stir at 30-40°C for 30-60 minutes to obtain an aminobis(methylenephosphonic acid) / Ag complex;

[0017] B2: Add 0.5-2 parts of methylallyl tri-n-butyltin to a reaction kettle by weight, add 3-6 parts of triethylamine dropwise to the reaction kettle, react at 50-70°C for 50-90 minutes, then add 200-400 parts of thiol-modified graphene, stir and react at 50-70°C for 200-250 minutes, centrifuge, wash, and dry to obtain a silver / tin composite hybrid graphene material.

[0018] Preparation mechanism of the above silver / tin composite hybrid graphene material:

[0019] 1. Aminobis(methylenephosphonic acid) reacts with AgNO3 to obtain aminobis(methylenephosphonic acid) / Ag complex;

[0020] 2. Methylallyl tri-n-butyltin undergoes an amino-ene addition reaction with an aminobis(methylenephosphonic acid) / Ag complex; then undergoes a thiol-ene addition reaction with thiol-treated graphene; and an amino-thiol addition reaction to obtain a silver / tin composite hybrid graphene material; metallic Ag particles can be grown between graphene sheets, thereby enhancing the conductivity of the ink and preventing the stacking of graphene sheets.

[0021] Technical effect:

[0022] The present invention provides a method for preparing a conductive ink. Compared with the prior art, the present invention has the following significant effects:

[0023] 1. The silver / tin composite hybrid graphene material prepared by the present invention is more suitable for the preparation of conductive ink than pure graphene; it can reduce the production cost of conductive ink and significantly reduce its weight;

[0024] 2. In the present invention, methylallyl tri-n-butyltin and aminobis(methylenephosphonic acid) / Ag complex undergo an amino-ene addition reaction to form a corresponding addition product, which then undergoes a thiol-ene addition reaction with thiol-treated graphene. Finally, an amino-thiol addition reaction occurs to obtain a silver / tin composite hybrid graphene material. Through these reactions, silver particles are able to grow between graphene sheets, thereby enhancing the conductivity of the ink and preventing the stacking of graphene sheets. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a printed image of the conductive ink prepared in Example 2. DETAILED DESCRIPTION

[0026] In order to more clearly illustrate the overall concept of the application, the following is described in detail in the form of embodiments. In the following description, a large amount of specific details are provided so that a more thorough understanding of the application is provided. However, it will be apparent to those skilled in the art that the application can be implemented without the need for one or more of these details. In other examples, in order to avoid confusion with the application, some technical features well known in the art are not described.

[0027] The conductivity of ink is characterized by resistivity. The smaller the resistivity, the better the conductivity of the ink: cut a square sample with an area of ​​4cm×4cm, take 9 points (3×3) on the coating surface and test the square resistance with a four-point probe analyzer, measure the coating thickness with a spiral micrometer, and then calculate the resistivity of the coating and take the average value.

[0028] Example 1

[0029] A method for preparing conductive ink, the operating steps are:

[0030] A1: Weigh 10g of waterborne acrylic resin, 1g of propylene glycol, 0.1g of leveling agent, 0.1g of pH adjuster, 40g of silver / tin hybrid graphene material, 0.1g of defoamer, and 24g of deionized water, and mix and stir for 20min.

[0031] A2: Slowly add 0.5 g of thickener and continue stirring for 20 minutes to obtain conductive ink.

[0032] The leveling agent is German Digo leveling agent 100.

[0033] The pH regulator is citric acid.

[0034] The defoamer is a polyether defoamer.

[0035] The thickener is a polyurethane thickener.

[0036] The preparation method of the silver / tin composite hybrid graphene material is:

[0037] B1: Weigh 20 g of aminobis(methylenephosphonic acid), 17 g of AgNO3, and 2000 g of N-methylpyrrolidone, add them to a reaction kettle, and stir at 30°C for 30 min to obtain an aminobis(methylenephosphonic acid) / Ag complex;

[0038] B2: 0.5 g of methylallyl tri-n-butyltin was added to a reactor, and 3 g of triethylamine was added dropwise to the reactor. After reacting at 50°C for 50 min, 200 g of thiol-modified graphene was added. After stirring and reacting at 50°C for 200 min, the reaction was centrifuged, washed, and dried to obtain a silver / tin composite hybrid graphene material.

[0039] The resistivity of the conductive ink prepared in this example was 1.51X10 -6 Ω·m.

[0040] Example 2

[0041] A method for preparing conductive ink, the operating steps are:

[0042] A1: Weigh 12g of waterborne acrylic resin, 2g of propylene glycol, 0.5g of leveling agent, 0.2g of pH adjuster, 43g of silver / tin hybrid graphene material, 0.2g of defoamer, and 30g of deionized water, and stir for 25min.

[0043] A2: Slowly add 0.8 g of thickener and continue stirring for 25 minutes to obtain conductive ink.

[0044] The leveling agent is German Digo leveling agent 410.

[0045] The pH regulator is lactic acid.

[0046] The defoamer is a polyether defoamer.

[0047] The thickener is a polyurethane thickener.

[0048] The preparation method of the silver / tin composite hybrid graphene material is:

[0049] B1: Weigh 25 g of aminobis(methylenephosphonic acid), 22 g of AgNO3, and 2400 g of N-methylpyrrolidone, add them to a reaction kettle, and stir at 35°C for 40 min to obtain an aminobis(methylenephosphonic acid) / Ag complex;

[0050] B2: 1 g of methylallyl tri-n-butyltin was added to a reactor, and 4 g of triethylamine was added dropwise to the reactor. After reacting at 55°C for 60 min, 250 g of thiol-modified graphene was added, and the reaction was stirred at 55°C for 220 min. The reaction was then centrifuged, washed, and dried to obtain a silver / tin composite hybrid graphene material.

[0051] The resistivity of the conductive ink prepared in this example was 1.47X10 -6 Ω·m.

[0052] Example 3

[0053] A method for preparing conductive ink, the operating steps are:

[0054] A1: Weigh 14 g of waterborne acrylic resin, 4 g of propylene glycol, 0.8 g of leveling agent, 0.2 g of pH adjuster, 48 g of silver / tin hybrid graphene material, 0.4 g of defoamer, and 36 g of deionized water, and mix and stir for 35 min.

[0055] A2: Slowly add 1.3 g of thickener and continue stirring for 35 minutes to obtain conductive ink.

[0056] The leveling agent is German Digo leveling agent 411.

[0057] The pH regulator is tartaric acid.

[0058] The defoamer is a polyether defoamer.

[0059] The thickener is a polyurethane thickener.

[0060] The preparation method of the silver / tin composite hybrid graphene material is:

[0061] B1: Weigh 35 g of aminobis(methylenephosphonic acid), 30 g of AgNO3, and 2800 g of N-methylpyrrolidone, add them to a reaction kettle, and stir at 35°C for 50 min to obtain an aminobis(methylenephosphonic acid) / Ag complex;

[0062] B2: 1.5 g of methylallyl tri-n-butyltin was added to a reactor, and 5 g of triethylamine was added dropwise to the reactor. After reacting at 65° C. for 80 min, 350 g of thiol-modified graphene was added, and the reaction was stirred at 65° C. for 240 min. The reaction was then centrifuged, washed, and dried to obtain a silver / tin composite hybrid graphene material.

[0063] The resistivity of the conductive ink prepared in this example was 1.40X10 -6 Ω·m.

[0064] Example 4

[0065] A method for preparing conductive ink, the operating steps are:

[0066] A1: Weigh 15g of waterborne acrylic resin, 5g of propylene glycol, 1g of leveling agent, 0.3g of pH adjuster, 50g of silver / tin composite hybrid graphene material, 0.5g of defoamer, and 40g of deionized water, and mix and stir for 40min;

[0067] A2: Slowly add 1.5 g of thickener and continue stirring for 40 minutes to obtain conductive ink.

[0068] The leveling agent is German Digo leveling agent 37.

[0069] The pH regulator is malic acid.

[0070] The defoamer is a polyether defoamer.

[0071] The thickener is a polyurethane thickener.

[0072] The preparation method of the silver / tin composite hybrid graphene material is:

[0073] B1: Weigh 40 g of aminobis(methylenephosphonic acid), 34 g of AgNO3, and 3000 g of N-methylpyrrolidone into a reaction kettle and stir at 40°C for 60 min to obtain an aminobis(methylenephosphonic acid) / Ag complex;

[0074] B2: 2 g of methylallyl tri-n-butyltin was added to a reactor, and 6 g of triethylamine was added dropwise to the reactor. After reacting at 70°C for 90 min, 400 g of thiol-modified graphene was added. After stirring and reacting at 70°C for 250 min, the reaction was centrifuged, washed, and dried to obtain a silver / tin composite hybrid graphene material.

[0075] The resistivity of the conductive ink prepared in this example was 1.36X10 -6 Ω·m.

[0076] Comparative Example 1

[0077] No silver / tin composite hybrid graphene material was added, and ordinary graphene material was added. Other aspects were the same as in Example 1.

[0078] The resistivity of the conductive ink prepared in this example was 2.72X10 -6 Ω·m.

[0079] Comparative Example 2

[0080] No aminodi(methylenephosphonic acid) was added, and the other steps were the same as in Example 1.

[0081] The test shows that the resistivity of the conductive ink prepared in this example is 1.87X10 -6 Ω·m.

[0082] Comparative Example 3

[0083] The other steps were the same as in Example 1 except that methylallyl tri-n-butyltin was not added.

[0084] The resistivity of the conductive ink prepared in this example was 1.65X10 -6 Ω·m.

[0085] Through the data analysis of the above examples and comparative examples, the silver / tin composite hybrid graphene material prepared by the present invention can effectively enhance the conductive properties of ink.

Claims

1. A method for preparing a conductive ink, comprising the following steps: A1: Weigh 10-15 parts of water-based acrylic resin, 1-5 parts of propylene glycol, 0.1-1 parts of leveling agent, 0.1-0.3 parts of pH adjuster, 40-50 parts of silver / tin composite hybrid graphene material, 0.1-0.5 parts of defoaming agent, and 24-40 parts of deionized water, and mix and stir for 20-40 minutes. A2: Slowly add 0.5-1.5 parts of thickener and continue stirring for 20-40 minutes to obtain conductive ink; The preparation method of the silver / tin composite hybrid graphene material is: B1: Weigh 20-40 parts of aminobis(methylenephosphonic acid), 17-34 parts of AgNO3, and 2000-3000 parts of N-methylpyrrolidone by weight, add them to a reaction kettle, and stir at 30-40°C for 30-60 minutes to obtain an aminobis(methylenephosphonic acid) / Ag complex; B2: Add 0.5-2 parts of methylallyl tri-n-butyltin to a reaction kettle by weight, add 3-6 parts of triethylamine dropwise to the reaction kettle, react at 50-70°C for 50-90 minutes, then add 200-400 parts of thiol-modified graphene, stir and react at 50-70°C for 200-250 minutes, centrifuge, wash, and dry to obtain a silver / tin composite hybrid graphene material.

2. The method for preparing a conductive ink according to claim 1, wherein: The leveling agent is one of German Digo leveling agents 100, 410, 411, 415, 435, 432, 440, 450, 482, B1484, 300, and 370.

3. The method for preparing a conductive ink according to claim 1, wherein: The pH regulator is one of citric acid, lactic acid, tartaric acid, malic acid and metatartaric acid.

4. The method for preparing a conductive ink according to claim 1, wherein: The defoamer is a polyether defoamer.

5. The method for preparing a conductive ink according to claim 1, wherein: The thickener is a polyurethane thickener.

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