Composite conductive ink-jet ink and preparation method thereof

Abstract

The invention relates to the technical field of printing electronic ink, and discloses a preparation method of composite conductive ink-jet ink, which comprises the following steps: S1, preparing conductive particles: drying the conductive particles, taking out, and carrying out surface treatment to improve the dispersibility and stability of the conductive particles; s2, solvent pretreatment: putting a solvent into a container, then adding hexadecyl trimethyl ammonium chloride and lauryl sodium sulfate into the solvent, and mixing the hexadecyl trimethyl ammonium chloride, the lauryl sodium sulfate and the solvent through stirring equipment to form a mixed solution A; s3, preparing a substrate: suspending conductive particles in the mixed solution A obtained in S2, adding a pigment, and uniformly dispersing the conductive particles and the pigment in the mixed solution A through stirring equipment to obtain a conductive solution A; by adding the hexadecyl trimethyl ammonium chloride and the lauryl sodium sulfate, the hexadecyl trimethyl ammonium chloride and the lauryl sodium sulfate can interact with anions or cations on the surfaces of the conductive particles to form a layer of stable charge barrier to prevent particle aggregation, so that the distribution uniformity of the conductive particles is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of printing electronic inks, and particularly to a composite conductive inkjet ink and a preparation method thereof. Background Art

[0002] Composite conductive inkjet ink is a special ink for inkjet printing. It is usually composed of conductive particles, solvents and other additives. The conductive particles can be conductive materials such as metals or carbon nanotubes, and their function is to make the ink have conductive properties. This ink can be ejected onto the printing medium through a nozzle and form patterns or characters as needed. Composite conductive inkjet ink has a wide range of applications in the fields of electronic device manufacturing, flexible electronics, sensors, etc. It can be used in the manufacture of devices such as printed circuit boards, conductive films, and sensor electrodes.

[0003] Currently, most of the conductive materials added to conductive inks are in the form of tiny particles, which makes it easy for the conductive materials in the ink to attract each other, and the conductive materials are easily attracted by charges and aggregated together, which not only affects the conductive performance of the ink, but also affects the fluidity of the ink. Therefore, the present invention provides a composite conductive inkjet ink and a preparation method thereof. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a composite conductive inkjet ink and a preparation method thereof, which solves the problem that the conductive materials in the existing conductive ink are easily attracted by charges and aggregated together, affecting the conductive performance of the ink.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A composite conductive inkjet ink, comprising the following raw materials in parts by mass:

[0006] 120 - 270 parts of conductive particles, 1000 - 1450 parts of solvent, 24 - 38 parts of polyvinyl alcohol, 13 - 19 parts of cetyltrimethylammonium chloride, 7 - 15 parts of sodium dodecyl sulfate, 18 - 26 parts of hydroxypropyl methylcellulose, and 32 - 47 parts of pigment.

[0007] Preferably, the conductive particles are any one of silver particles, copper particles or carbon nanotubes.

[0008] Preferably, the solvent is any one of water, ethanol, acetone or glycerol.

[0009] A preparation method of a composite conductive inkjet ink, comprising the following steps:

[0010] S1. Prepare conductive particles: Take out the conductive particles after drying and perform surface treatment to improve their dispersibility and stability;

[0011] S2. Solvent pretreatment: Put the solvent into a container, then add cetyltrimethylammonium chloride and sodium dodecyl sulfate into the solvent, and mix the three with a stirring device to form a mixed solution A;

[0012] S3. Substrate preparation: Suspend the conductive particles in the mixed solution A obtained in S2, and add the pigment at the same time. Meanwhile, disperse the conductive particles and the pigment evenly in the mixed solution A with a stirring device to obtain a conductive solution A;

[0013] S4. Ink preparation: Place the conductive solution A obtained in S3 into an ultrasonic device, add polyvinyl alcohol and hydroxypropyl methylcellulose, and make the particles evenly dispersed in the conductive solution A through ultrasonic treatment to form a stable ink;

[0014] S5. Adjust the ink properties: According to needs, the viscosity, conductivity and color parameters of the ink can be further adjusted;

[0015] S6. Filtration and purification: Filter and purify the ink to remove impurities and large particles to ensure the quality and stability of the ink.

[0016] Preferably, the surface treatment in S1 is ball milling. The conductive particles are ball milled by using a ball mill device to reduce the particle size and increase the surface area, thereby improving the dispersibility of the particles.

[0017] Preferably, the stirring device in S2 operates at room temperature, with a stirring speed of 230 - 370 r / min, a stirring time of 4 - 7 min, and a pressure of 225 - 285 kPa.

[0018] Preferably, the stirring device used in S3 is a high - shear stirrer, with a rotation speed of 900 - 1250 r / min, operating at room temperature and normal pressure, and a stirring time of 3 - 5 min.

[0019] Preferably, the frequency of the ultrasonic device in S4 is 20 - 70 kHz, the power density is usually 0.5 W / cm 2 ~3 W / cm 2 , the temperature is 25 - 28 °C, and the treatment time is 8 - 12 min.

[0020] Preferably, in S5, the viscosity, conductivity and color parameters of the ink are adjusted by adding solvents, pigments or adjusting the content of conductive particles.

[0021] Preferably, the filtration and purification in S6 include:

[0022] Primary filtration: Use filter paper with a larger pore size for preliminary filtration to remove larger impurities and particles;

[0023] Microfiltration: The ink is further finely filtered through a microporous membrane to remove smaller particles and impurities.

[0024] The present invention provides a composite conductive inkjet ink and a preparation method thereof. It has the following beneficial effects:

[0025] 1. By adding cetyltrimethylammonium chloride and sodium dodecyl sulfate, the present invention can interact with anions or cations on the surface of conductive particles to form a stable charge barrier, preventing particle aggregation, thereby ensuring the uniformity of the distribution of conductive particles, improving the conductivity of the ink and to a certain extent improving the flowability of the ink.

[0026] 2. By adding hydroxypropyl methylcellulose, the present invention can increase the viscosity of the ink, thereby improving the flowability of the ink, and will not affect the dispersibility of the internal conductive particles, thereby improving the fluidity of the ink. At the same time, it can inhibit the movement state of the conductive particles inside the ink, further avoiding contact deposition between the conductive particles, thereby improving the stability of the ink. Specific Embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] Embodiment 1:

[0029] The embodiment of the present invention provides a composite conductive inkjet ink, including the following raw materials in parts by mass:

[0030] 160 parts of conductive particles, 1300 parts of solvent, 28 parts of polyvinyl alcohol, 16 parts of cetyltrimethylammonium chloride, 13 parts of sodium dodecyl sulfate, 23 parts of hydroxypropyl methylcellulose, and 37 parts of pigment.

[0031] The conductive particles are silver particles.

[0032] The solvent is water.

[0033] A preparation method of a composite conductive inkjet ink includes the following steps:

[0034] S1. Prepare conductive particles: Take out the conductive particles after drying, and perform ball milling on the conductive particles by using a ball mill device to reduce the particle size and increase the surface area, thereby improving the dispersibility of the particles;

[0035] S2. Solvent Pretreatment: Put the solvent into a container, then add cetyltrimethylammonium chloride and sodium dodecyl sulfate into the solvent, and mix the three through a stirring device to form a mixed solution A. The stirring is carried out at room temperature, with a stirring speed of 275 r / min, a stirring time of 5.5 min, and a pressure of 260 kPa.

[0036] S3. Substrate Preparation: Suspend the conductive particles in the mixed solution A obtained in S2, and add the pigment together. At the same time, evenly disperse the conductive particles and the pigment in the mixed solution A through a stirring device to obtain a conductive solution A. The stirring device is a high-shear stirrer with a rotation speed of 1100 r / min, carried out at room temperature and normal pressure, and the stirring time is 4 min.

[0037] S4. Ink Preparation: Place the conductive solution A obtained in S3 inside an ultrasonic device, add polyvinyl alcohol and hydroxypropyl methylcellulose, and through ultrasonic treatment, make the particles evenly disperse in the conductive solution A to form a stable ink. The frequency of the ultrasonic device is 55 kHz, and the power density is usually in the range of 1.2 W / cm 2 ~3 W / cm 2 , the temperature is 27 °C, and the treatment time is 11 min.

[0038] S5. Adjust Ink Properties: According to needs, the viscosity, conductivity, and color parameters of the ink can be further adjusted by adding solvents, pigments, or adjusting the content of conductive particles.

[0039] S6. Filtration and Purification: Filter and purify the ink. Primary Filtration: Use filter paper with a larger pore size for preliminary filtration to remove larger impurities and particles; Microfiltration: Pass the ink through a microporous membrane for further fine filtration to remove smaller particles and impurities, ensuring the quality and stability of the ink to obtain conductive ink.

[0040] Conduct a full test on the obtained conductive ink. The stability, particle dispersion, fluidity, conductivity, and particle distribution uniformity of the finally measured conductive ink are shown in Table 1 below.

[0041] Example 2:

[0042] The present invention provides a composite conductive inkjet ink, which includes the following raw materials in parts by mass:

[0043] 220 parts of conductive particles, 1420 parts of solvent, 33 parts of polyvinyl alcohol, 17 parts of cetyltrimethylammonium chloride, 8 parts of sodium dodecyl sulfate, 22 parts of hydroxypropyl methylcellulose, 43 parts of pigment. The remaining preparation process steps are the same as those in Example 1, and the same method is used for testing. The stability, particle dispersibility, fluidity, electrical conductivity, and particle distribution uniformity of the finally obtained conductive ink are shown in Table 1 below.

[0044] Example 3:

[0045] An embodiment of the present invention provides a composite conductive inkjet ink, comprising the following raw materials in parts by mass:

[0046] 180 parts of conductive particles, 1150 parts of solvent, 26 parts of polyvinyl alcohol, 17 parts of cetyltrimethylammonium chloride, 9 parts of sodium dodecyl sulfate, 20 parts of hydroxypropyl methylcellulose, 46 parts of pigment. The remaining preparation process steps are the same as those in Example 1, and the same method is used for testing. The stability, particle dispersibility, fluidity, electrical conductivity, and particle distribution uniformity of the finally obtained conductive ink are shown in Table 1 below.

[0047] Example 4:

[0048] An embodiment of the present invention provides a preparation method of a composite conductive inkjet ink. Delete the S2 step in Example 1. The remaining preparation process and raw materials are the same as those in Example 1, and the same method is used for testing. The stability, particle dispersibility, fluidity, electrical conductivity, and particle distribution uniformity of the finally obtained conductive ink are shown in Table 1 below.

[0049] Example 5:

[0050] An embodiment of the present invention provides a preparation method of a composite conductive inkjet ink. Remove the cetyltrimethylammonium chloride or sodium dodecyl sulfate in Example 1. The remaining preparation process and raw materials are the same as those in Example 1, and the same method is used for testing. The stability, particle dispersibility, fluidity, electrical conductivity, and particle distribution uniformity of the finally obtained conductive ink are shown in Table 1 below.

[0051] Example 6:

[0052] An embodiment of the present invention provides a preparation method of a composite conductive inkjet ink. Remove the hydroxypropyl methylcellulose in Example 1. The remaining preparation process and raw materials are the same as those in Example 1, and the same method is used for testing. The stability, particle dispersibility, fluidity, electrical conductivity, and particle distribution uniformity of the finally obtained conductive ink are shown in Table 1 below.

[0053] Example 7:

[0054] An embodiment of the present invention provides a method for preparing a composite conductive inkjet ink. Remove the hydroxypropyl methylcellulose, cetyltrimethylammonium chloride, and sodium dodecyl sulfate in Example 1. The remaining preparation processes and raw materials are the same as those in Example 1, and the same method is used for testing. The stability, particle dispersibility, fluidity, conductivity, and particle distribution uniformity of the finally obtained conductive ink are shown in Table 1 below.

[0055]

[0056] Table 1

[0057] Conclusion: When preparing the conductive ink, by adding cetyltrimethylammonium chloride and sodium dodecyl sulfate, they can interact with anions or cations on the surface of the conductive particles to form a stable charge barrier, preventing particle aggregation, thereby ensuring the uniformity of the distribution of the conductive particles, improving the conductivity of the ink, and to a certain extent improving the flow performance of the ink. By adding hydroxypropyl methylcellulose, the viscosity of the ink can be increased, thereby improving the flow performance of the ink, and it will not affect the dispersibility of the internal conductive particles, thereby improving the fluidity of the ink. At the same time, it can inhibit the movement state of the conductive particles inside the ink, further avoiding contact deposition between the conductive particles, thereby improving the stability of the ink.

[0058] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A composite conductive inkjet ink, characterized in that, It includes raw materials in the following parts by mass: 120 - 270 parts of conductive particles, 1000 - 1450 parts of solvent, 24 - 38 parts of polyvinyl alcohol, 13 - 19 parts of cetyltrimethylammonium chloride, 7 - 15 parts of sodium dodecyl sulfate, 18 - 26 parts of hydroxypropyl methylcellulose, and 32 - 47 parts of pigment.

2. The composite conductive inkjet ink according to claim 1, characterized in that The conductive particles are any one of silver particles, copper particles or carbon nanotubes.

3. A composite conductive inkjet ink according to claim 1, wherein The solvent is any one of water, ethanol, acetone or glycerol.

4. A preparation method of a composite conductive inkjet ink, characterized in that, A composite conductive inkjet ink according to any one of claims 1 - 3 includes the following steps: S1. Prepare conductive particles: Take out the dried conductive particles and perform surface treatment to improve their dispersibility and stability; S2. Solvent pretreatment: Put the solvent into a container, then add cetyltrimethylammonium chloride and sodium dodecyl sulfate into the solvent, and mix the three with a stirring device to form a mixed solution A; S3. Configure the substrate: Suspend the conductive particles in the mixed solution A obtained in S2, and add the pigment together. At the same time, evenly disperse the conductive particles and the pigment in the mixed solution A with a stirring device to obtain a conductive solution A; S4. Ink configuration: Place the conductive solution A obtained in S3 into an ultrasonic device, add polyvinyl alcohol and hydroxypropyl methylcellulose, and make the particles evenly disperse in the conductive solution A through ultrasonic treatment to form a stable ink; S5. Adjust the ink properties: According to needs, the viscosity, conductivity and color parameters of the ink can be further adjusted; S6. Filtration and purification: Filter and purify the ink to remove impurities and large particles to ensure the quality and stability of the ink and obtain a conductive ink.

5. The preparation method of a composite conductive inkjet ink according to claim 4, characterized in that, The surface treatment in S1 is ball milling. Use a ball milling device to perform ball milling on the conductive particles to reduce the particle size and increase the surface area, thereby improving the dispersibility of the particles.

6. The preparation method of a composite conductive inkjet ink according to claim 4, characterized in that, The stirring device in S2 operates at room temperature, with a stirring speed of 230 - 370 r / min, a stirring time of 4 - 7 min, and a pressure of 225 - 285 kPa.

7. The preparation method of a composite conductive inkjet ink according to claim 4, characterized in that, The stirring device used in S3 is a high - shear stirrer with a rotation speed of 900 - 1250 r / min, operating at room temperature and normal pressure, and the stirring time is 3 - 5 min.

8. The preparation method of a composite conductive inkjet ink according to claim 4, wherein, In S4, the frequency of the ultrasonic device is 20 - 70 kHz, and the power density is usually 0.5 W / cm 2 ~3 W / cm 2 , the temperature is 25 - 28 °C, and the treatment time is 8 - 12 min.

9. The preparation method of a composite conductive inkjet ink according to claim 4, characterized in that, In S5, the viscosity, conductivity and color parameters of the ink are adjusted by adding solvent, pigment or adjusting the content of conductive particles.

10. The preparation method of a composite conductive inkjet ink according to claim 4, characterized in that, The filtration and purification in S6 include: Primary filtration: Use filter paper with a larger pore size for preliminary filtration to remove larger impurities and particles; Microfiltration: Further finely filter the ink through a microfiltration membrane to remove smaller particles and impurities.

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