Environmentally friendly ink and preparation method thereof

Abstract

The present invention belongs to the technical field of ink, and specifically relates to an environmentally friendly ink and a preparation method thereof. The ink comprises the following components by weight: 10 to 14 parts of carbon nanotubes; 1 to 3 parts of acid-modified graphene oxide; 100 parts of water-based acrylic resin; 4 to 8 parts of dispersant; 2 to 4 parts of silane coupling agent; and 140 to 180 parts of water. The carbon nanotubes prepared by the present invention through a specific process, acid-modified graphene oxide, and the selection of the dispersant make the components dispersed evenly and have excellent conductive properties. The ink of the present invention is widely used and has a good application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of inks, and more specifically, relates to an environmentally friendly ink and a preparation method thereof. Background Art

[0002] Conductive ink is composed of conductive fillers, binders, solvents and additives. Conductive fillers are the key factor affecting the conductivity of conductive ink. Generally speaking, binders are non-conductive and contain natural polymer resins and synthetic resins. The main function of the binder is to connect the conductive fillers in the ink together to form a conductive path and form a conductive coating on the substrate during the printing process. Solvents include organic solvents and water. Their main functions are to dissolve fillers, adjust viscosity, improve the wettability of ink to the printed substrate, and adjust the drying speed of ink. The additives are present in a small amount in the ink and can improve the performance of the ink. Commonly used additives include defoamers, leveling agents, dispersants, etc. Among them, defoamers can remove bubbles in water-based inks and improve the printing quality of printed products; leveling agents can make the ink form a flat, smooth and uniform ink layer; dispersants can make the material fillers evenly dispersed in the solution to prevent the sedimentation and agglomeration of solid particles, thereby improving the performance of the ink.

[0003] Conductive inks are widely used in the manufacture of electronic tags, printed circuit boards, electronic switches, membrane switches, low-cost solar cells, smart carpets and other products. They are also widely used in flexible printed electronics, automobiles, healthcare, in-mold electronics and sensors. The key to forming conductive circuits on substrates (without copper foil) using fast, efficient and flexible digital inkjet printing technology lies in the research and development of conductive ink functional materials. Existing conductive inks have many disadvantages, and it is necessary to develop a conductive ink with low cost, good conductivity and stable performance.

[0004] CN106009905A discloses a water-based ink and a preparation method thereof. The present invention provides a water-based ink, the raw materials of which include disperse dyes, water-based polyurethane, dispersants, cosolvents and deionized water. The present invention also provides a preparation method of the water-based ink, which includes the following steps: step 1, mixing the dispersant, disperse dyes and a first amount of deionized water, grinding to obtain a first product; step 2, stirring the first product, adjusting the pH to 7.0-7.5 to obtain a second product; step 3, sequentially adding water-based polyurethane, cosolvents and a second amount of deionized water to the second product, mixing to obtain a product. Experimental measurements show that the obtained product can meet the requirements of printability, storage stability, drying, heat transfer rate and color fastness after transfer, while taking into account safety and environmental protection.

[0005] CN113292885A discloses a water-based plastic inkjet type high-adhesion ink and a preparation method thereof. The raw material components are calculated by weight as follows: 6-20 parts of water-based acrylic ester emulsion, 8-20 parts of water-based color paste, 10-20 parts of organic solvent, 100-140 parts of deionized water, 1-4 parts of film-forming aid, 1-8 parts of surfactant, 1-6 parts of leveling agent, and 1-6 parts of defoaming agent. The emulsion water-based plastic film inkjet printing ink is safe and environmentally friendly, has low VOC content, low odor, low viscosity, moderate surface drying speed, and good wetting performance. The ink is used to print a test picture on a print nozzle, and the continuous printing time is 2 hours. The test strip before and after printing has no broken lines or slanted lines. After that, the machine is turned off and waited for 2 hours, and the test strip is printed again for testing. The test strip is intact without broken lines or slanted lines, and the ink has excellent performance.

[0006] It is known from the prior art that the conductivity of ink can be improved by adding conductive components, but there are problems such as high viscosity. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the defects and shortcomings of the prior art and provide an environmentally friendly ink and a preparation method thereof. In parts by weight, the ink comprises the following components: carbon nanotubes; 10 to 14 parts; acid-modified graphene oxide: 1 to 3 parts; water-based acrylic resin: 100 parts; dispersant: 4 to 8 parts; silane coupling agent: 2 to 4 parts; water 140 to 180 parts. The carbon nanotubes prepared by the present invention through a specific process, acid-modified graphene oxide, and the selection of the dispersant make the components evenly dispersed and have excellent conductive properties. The ink of the present invention is widely used and has a good application prospect.

[0008] The purpose of the present invention is to provide an environmentally friendly ink.

[0009] Another object of the present invention is to provide a method for preparing an environmentally friendly ink.

[0010] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0011] An environmentally friendly ink, comprising the following components by weight:

[0012] Carbon nanotubes: 10-14 parts;

[0013] Acid-modified graphene oxide: 1 to 3 parts;

[0014] Water-based acrylic resin: 100 parts;

[0015] Dispersant: 4-8 parts;

[0016] Silane coupling agent: 2-4 parts;

[0017] 140-180 parts of water.

[0018] In the present invention, a preferred embodiment is that the dispersant is octanol polyoxyethylene ether, sodium dodecylbenzene sulfonate and Sago-9710; further preferably, the mass ratio of octanol polyoxyethylene ether, sodium dodecylbenzene sulfonate and Sago-9710 is 1:3:4; further preferably, the silane coupling agent is at least one of KH-602, KH-550 and KH-570.

[0019] In the present invention, in a preferred embodiment, the method for preparing the carbon nanotubes is as follows:

[0020] (1) mixing copper salt, iron salt, 2-methylimidazole and ethanol and reacting them to obtain MOFs material;

[0021] (2) mixing the MOFs material obtained in step (1), thiophene and ethanol, and reacting the mixed solution under a mixed gas condition of hydrogen and nitrogen at 700-800° C. for 10-16 hours to obtain carbon nanotubes;

[0022] Preferably, in step (1), the molar ratio of the copper salt, the iron salt and 2-methylimidazole is 4:1:1.8; the copper salt is at least one of copper nitrate, copper chloride and copper acetate; and the iron salt is at least one of iron nitrate, iron chloride and iron acetate.

[0023] Preferably, in step (1), the reaction conditions are 50-90° C. for 18-26 hours.

[0024] Preferably, in step (2), the ratio of the MOFs material obtained in step (1) to thiophene is 1 g: 0.2-0.4 mmol: 20-40 mL.

[0025] Preferably, in step (2), the volume ratio of hydrogen to nitrogen is 3:4.

[0026] In the present invention, a preferred embodiment, the method for preparing the acid-modified graphene oxide comprises the following steps:

[0027] The graphene oxide is added into a nitric acid solution, subjected to heat treatment, filtered, washed and dried to obtain acid-modified graphene oxide.

[0028] Preferably, the concentration of the nitric acid is 2 to 4 mol / L; and the heat treatment condition is heat treatment at 40 to 60° C. for 6 to 10 hours.

[0029] Based on the above-mentioned method for preparing an environmentally friendly ink, the preparation method comprises the following steps:

[0030] The carbon nanotubes, acid-modified graphene oxide, aqueous acrylic resin, dispersant and water are uniformly mixed, and then ball-milled at room temperature. The rotation speed of the ball-milling is 1500-1700 r / min, and the ball-milling time is 1-3 hours.

[0031] The present invention has the following beneficial effects:

[0032] (1) The carbon nanotubes prepared by the specific process of the present invention, combined with acid-modified graphene oxide, can promote the improvement of the conductive properties of ink;

[0033] (2) By selecting a dispersant with a specific composition, the dispersibility of carbon nanotubes and graphene oxide can be significantly improved, and the conductivity and other properties of the ink can be improved.

[0034] (3) The environmentally friendly ink prepared by the present invention has excellent performance and is widely applicable. DETAILED DESCRIPTION

[0035] The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0036] Water-based acrylic resin: E0503 water-based acrylic resin, with a solid content of 35%, was obtained from Shenzhen Yoshida Chemical Co., Ltd.

[0037] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0038] Example 1

[0039] An environmentally friendly ink, comprising the following components by weight:

[0040] Carbon nanotubes: 12 parts;

[0041] Acid-modified graphene oxide: 2 parts;

[0042] Water-based acrylic resin: 100 parts;

[0043] Dispersant: 6 parts; the dispersant is octanol polyoxyethylene ether, sodium dodecylbenzene sulfonate and Sago-9710; the mass ratio of octanol polyoxyethylene ether, sodium dodecylbenzene sulfonate and Sago-9710 is 1:3:4;

[0044] Silane coupling agent: 3 parts; the silane coupling agent is KH-602;

[0045] 160 parts water;

[0046] The preparation method of the carbon nanotubes is as follows:

[0047] (1) 4 mol of copper nitrate, 1 mol of iron nitrate, 1.8 mol of 2-methylimidazole and 250 mL of ethanol were mixed and reacted at 70° C. for 22 h to obtain a MOFs material;

[0048] (2) 10 g of the MOFs material obtained in step (1), 3 mmol of thiophene and 300 mL of ethanol were mixed, and the mixed solution was reacted at 750° C. for 14 h under a mixed gas condition of hydrogen and nitrogen (the volume ratio of hydrogen to nitrogen was 3:4) to obtain carbon nanotubes.

[0049] The preparation method of the acid-modified graphene oxide comprises the following steps:

[0050] 10 g of graphene oxide was added to 100 mL of 3 mol / L nitric acid solution, heat treated at 50° C. for 8 h, filtered, washed, and dried at 80° C. to constant weight to obtain acid-modified graphene oxide;

[0051] The method for preparing the environmentally friendly ink comprises the following steps:

[0052] The carbon nanotubes, acid-modified graphene oxide, aqueous acrylic resin, dispersant and water were uniformly mixed, and then ball-milled at room temperature. The rotation speed of the ball-milling was 1600 r / min, and the ball-milling time was 2 h.

[0053] Example 2

[0054] An environmentally friendly ink, comprising the following components by weight:

[0055] Carbon nanotubes: 14 parts;

[0056] Acid-modified graphene oxide: 1 part;

[0057] Water-based acrylic resin: 100 parts;

[0058] Dispersant: 8 parts; the dispersant is octanol polyoxyethylene ether, sodium dodecylbenzene sulfonate and Sago-9710; the mass ratio of octanol polyoxyethylene ether, sodium dodecylbenzene sulfonate and Sago-9710 is 1:3:4;

[0059] Silane coupling agent: 2 parts; the silane coupling agent is KH-550;

[0060] 180 parts water;

[0061] The method for preparing the carbon nanotubes is the same as the method for preparing the carbon nanotubes in Example 1.

[0062] The preparation method of the acid-modified graphene oxide is the same as the preparation method of the acid-modified graphene oxide in Example 1.

[0063] The method for preparing the environmentally friendly ink comprises the following steps:

[0064] The carbon nanotubes, acid-modified graphene oxide, aqueous acrylic resin, dispersant and water were uniformly mixed, and then ball-milled at room temperature. The rotation speed of the ball-milling was 1700 r / min, and the ball-milling time was 1 h.

[0065] Example 3

[0066] An environmentally friendly ink, comprising the following components by weight:

[0067] Carbon nanotubes: 10 parts;

[0068] Acid-modified graphene oxide: 3 parts;

[0069] Water-based acrylic resin: 100 parts;

[0070] Dispersant: 4 parts; the dispersant is octanol polyoxyethylene ether, sodium dodecylbenzene sulfonate and Sago-9710; the mass ratio of octanol polyoxyethylene ether, sodium dodecylbenzene sulfonate and Sago-9710 is 1:3:4;

[0071] Silane coupling agent: 4 parts; the silane coupling agent is at least one of KH-602, KH-550 and KH-570;

[0072] 140 parts water;

[0073] The method for preparing the carbon nanotubes is the same as the method for preparing the carbon nanotubes in Example 1.

[0074] The preparation method of the acid-modified graphene oxide is the same as the preparation method of the acid-modified graphene oxide in Example 1.

[0075] The method for preparing the environmentally friendly ink comprises the following steps:

[0076] The carbon nanotubes, acid-modified graphene oxide, aqueous acrylic resin, dispersant and water were uniformly mixed, and then ball-milled at room temperature. The rotation speed of the ball-milling was 1500 r / min, and the ball-milling time was 3 h.

[0077] Example 4

[0078] It is basically the same as Example 1, except that KH-550 is used instead of KH-602.

[0079] Example 5

[0080] The method is basically the same as Example 1, except that KH-570 is used instead of KH-602.

[0081] Comparative Example 1

[0082] The method is substantially the same as Example 1, except that 14 parts of carbon nanotubes are used to replace 12 parts of carbon nanotubes and 2 parts of acid-modified graphene oxide.

[0083] Comparative Example 2

[0084] The method is basically the same as Example 1, except that the carbon nanotubes are prepared as follows:

[0085] (1) 5 mol of copper nitrate, 1.8 mol of 2-methylimidazole and 250 mL of ethanol were mixed and reacted at 70° C. for 22 h to obtain MOFs material;

[0086] (2) 10 g of the MOFs material obtained in step (1), 3 mmol of thiophene and 300 mL of ethanol were mixed, and the mixed solution was reacted at 750° C. for 14 h under a mixed gas condition of hydrogen and nitrogen to obtain carbon nanotubes.

[0087] Comparative Example 3

[0088] The method is basically the same as Example 1, except that: the dispersant is sodium dodecylbenzene sulfonate and Sago-9710; and the mass ratio of sodium dodecylbenzene sulfonate to Sago-9710 is 4:4.

[0089] Comparative Example 4

[0090] It is basically the same as Comparative Example 3, except that the dispersant is Sago-9710.

[0091] The performance of Examples 1-5 and Comparative Examples 1-4 was tested, and the specific test standards were as follows:

[0092] Square resistance test: Use a four-probe square resistance tester and a multimeter to measure square resistance and resistivity;

[0093] Surface tension test: surface tension tester;

[0094] Adhesion: The adhesion of the ink layer is tested according to the national standard GB / T7706-2008 "Letterpress Decorative Printing".

[0095] The specific test results are shown in Table 1:

[0096] Table 1:

[0097]

[0098]

[0099] It can be seen from Table 1 that, by comparing the embodiments with the comparative examples, the carbon nanotubes prepared by the specific process of the present invention, combined with acid-modified graphene oxide, can promote the improvement of the conductive properties of the ink; by selecting a dispersant of a specific component to be added to the ink, the improvement of the ink is also promoted. The ink of the present invention has excellent properties such as conductivity and adhesion.

[0100] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. An environmentally friendly ink, characterized in that: The ink comprises the following components by weight: Carbon nanotubes: 10-14 parts; Acid-modified graphene oxide: 1-3 parts; Water-based acrylic resin: 100 parts; Dispersant: 4~8 parts; Silane coupling agent: 2~4 parts; Water: 140~180 parts; The dispersant is octanol polyoxyethylene ether, sodium dodecylbenzene sulfonate and Sago-9710; the mass ratio of octanol polyoxyethylene ether, sodium dodecylbenzene sulfonate and Sago-9710 is 1:3:4; the silane coupling agent is at least one of KH-602, KH-550 and KH-570; The preparation method of the carbon nanotubes is as follows: (1) copper salt, iron salt, 2-methylimidazole and ethanol are mixed and reacted to obtain MOFs material; the molar ratio of the copper salt, iron salt and 2-methylimidazole is 4:1:1.8; (2) Mixing the MOFs material obtained in step (1), thiophene and ethanol, and reacting the mixed solution under a mixed gas condition of hydrogen and nitrogen at 700-800° C. for 10-16 hours to obtain carbon nanotubes; the ratio of the MOFs material obtained in step (1), thiophene and ethanol is 1 g: 0.3 mmol: 30 mL; The preparation method of the acid-modified graphene oxide comprises the following steps: The graphene oxide is added into a nitric acid solution, subjected to heat treatment, filtered, washed and dried to obtain acid-modified graphene oxide.

2. The environmentally friendly ink according to claim 1, characterized in that: In step (1), the copper salt is at least one of copper nitrate, copper chloride and copper acetate; the iron salt is at least one of iron nitrate, iron chloride and iron acetate.

3. The environmentally friendly ink according to claim 1, characterized in that: In step (1), the reaction conditions are 50-90° C. for 18-26 hours.

4. The environmentally friendly ink according to claim 1, characterized in that: In step (2), the volume ratio of hydrogen to nitrogen is 3:

4.

5. The environmentally friendly ink according to claim 1, characterized in that: The concentration of the nitric acid is 2-4 mol / L; the heat treatment condition is heat treatment at 40-60° C. for 6-10 hours.

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