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CN-122011839-A - Conductive ink for micro-speaker diaphragm, preparation method thereof and micro-speaker diaphragm

CN122011839ACN 122011839 ACN122011839 ACN 122011839ACN-122011839-A

Abstract

The invention provides a conductive ink for a micro-speaker diaphragm, a preparation method thereof and the micro-speaker diaphragm, wherein the conductive ink comprises 10-60wt% of conductive filler, 10-70wt% of matrix resin, 10-70wt% of dispersion medium, 0.1-5.0wt% of silane coupling agent, 0.2-5.0wt% of dispersing agent, 0.05-1.0 of defoaming agent, 0.05-2.0 of antioxidant and 0.05-1.5 of ultraviolet absorbent, the matrix resin comprises an acrylic acid system resin, and the conductive ink can be suitable for the application scene of micro-speaker diaphragm under high-frequency vibration, large-amplitude stretching and high-humidity high-temperature through the mutual synergistic effect of the high-aspect ratio nanowire, the acrylic acid system resin and the anti-aging filler in the conductive ink, so that the dynamic reliability conductive problem of the micro-speaker diaphragm under 'high-frequency large-amplitude vibration + severe temperature and severe condition' can be well solved.

Inventors

  • XU FEILONG
  • DONG QINGBIN
  • ZHANG JUNLI

Assignees

  • 深圳市维仕声学有限公司

Dates

Publication Date
20260512
Application Date
20260305

Claims (18)

  1. 1. A conductive ink for a micro-speaker diaphragm, characterized by comprising 10-60wt% of a conductive filler, 10-70wt% of a matrix resin, 10-70wt% of a dispersion medium, 0.1-5.0wt% of a silane coupling agent, 0.2-5.0wt% of a dispersant, 0.05-1.0 of a defoaming agent, 0.05-2.0 of an antioxidant and 0.05-1.5 of an ultraviolet absorber; The conductive filler comprises nanowires with high length-diameter ratio; The matrix resin includes an acrylic system resin.
  2. 2. The conductive ink for a micro-speaker diaphragm of claim 1, wherein the nanowires comprise one or more of gold nanowires, silver nanowires, and copper nanowires.
  3. 3. The conductive ink for a micro-speaker diaphragm according to claim 1, wherein the aspect ratio of the nanowire is 100-3000.
  4. 4. A conductive ink for a micro-speaker diaphragm according to claim 3, wherein the aspect ratio of the nanowires is 800-1200.
  5. 5. The conductive ink for a micro-speaker diaphragm according to claim 1, wherein the body resin comprises one or more of an aqueous acrylic resin, an acrylate copolymer, an aqueous polyurethane, and an EVA emulsion.
  6. 6. The conductive ink for a micro-speaker diaphragm according to claim 1, wherein the dispersion medium comprises one or more of deionized water, ethanol, isopropanol, and ethylene glycol.
  7. 7. The conductive ink for a micro-speaker diaphragm according to claim 1, wherein the silane coupling agent comprises one or more of hydroxypropyl methylcellulose and hydroxyethyl cellulose.
  8. 8. The conductive ink for a micro-speaker diaphragm according to claim 1, wherein the dispersant comprises a pick chemistry BYK110, pick chemistry BYK103, pick chemistry BYK2013, and one or more of the di-height 755W.
  9. 9. The conductive ink for a micro-speaker diaphragm of claim 1, wherein the defoamer comprises one or more of silicones and mineral oils.
  10. 10. The conductive ink for a micro-speaker diaphragm according to claim 1, wherein the antioxidant comprises one or more of hindered phenols (1010) and phosphites (168).
  11. 11. The conductive ink for a micro-speaker diaphragm according to claim 1, wherein the ultraviolet absorber comprises one or more of benzotriazoles and benzophenones.
  12. 12. A method of preparing a conductive ink for a micro-speaker diaphragm according to any one of claims 1 to 11, comprising the steps of: Premixing a dispersion medium, a matrix resin, a defoaming agent, an antioxidant and an ultraviolet absorbent to obtain a stable mixed base material; Uniformly adding nanowire dispersion liquid into the mixed base material, then adding a dispersing agent to obtain conductive ink, and homogenizing; The conductive ink after the homogenization treatment is subjected to viscosity adjustment and filtration.
  13. 13. The method for preparing conductive ink for micro-speaker diaphragm according to claim 12, characterized in that said premixing comprises: Heating and stirring the dispersion medium by using a stirrer, wherein the heating temperature is 45-60 ℃, heating in a water bath, and the stirring rotating speed is 450-750/min; after the temperature is stable, adding matrix resin, a defoaming agent, an antioxidant and an ultraviolet absorber while stirring; After the addition, the rotating speed is adjusted to 900 1200R/min, continuing to disperse for 8 And (3) after 12min, closing the water bath heating and the stirrer, and discharging to obtain the stable mixed base material.
  14. 14. The method for preparing a conductive ink for a micro-speaker diaphragm according to claim 12, wherein the uniformly adding nanowire dispersion liquid and then dispersing agent to the mixed base material to obtain the conductive ink comprises: And (3) placing the mixed base material into a stirring tank, uniformly adding the nanowire dispersion liquid into the stirring tank at a second speed under the condition of continuously stirring at the first speed, finally adding the dispersing agent, adjusting the rotating speed to be 500-700r/min, stirring for 25-35min to uniformly disperse the nanowire dispersion liquid, stopping stirring, and discharging to obtain the conductive ink.
  15. 15. The method for preparing conductive ink for micro-speaker diaphragm according to claim 12, wherein the homogenizing treatment comprises transferring the obtained mixed ink into a planetary mixer for homogenizing and dispersing, and stirring at 400-800 rpm for 15-30 min until the system is uniform and stable without obvious agglomerates.
  16. 16. The method for preparing conductive ink for micro-speaker diaphragm according to claim 12, wherein the viscosity adjustment comprises: adding deionized water or an alcohol solvent into the homogenized conductive ink, and adjusting the conductive ink to a preset viscosity.
  17. 17. A micro-speaker diaphragm comprising a conductive ink for a micro-speaker diaphragm according to any one of claims 1 to 11.
  18. 18. The micro-speaker diaphragm of claim 17, wherein the conductive ink is disposed at any position of a long side or a short side of the micro-speaker diaphragm.

Description

Conductive ink for micro-speaker diaphragm, preparation method thereof and micro-speaker diaphragm Technical Field The invention relates to the field of micro-speaker diaphragms, in particular to conductive ink for a micro-speaker diaphragm, a preparation method thereof and the micro-speaker diaphragm. Background Micro-speaker systems are evolving towards high reliability and high electroacoustic conversion efficiency. The traditional scheme of connecting the voice coil with an external circuit by adopting a flexible circuit (FPC) has the conditions of occupied space, easy fatigue failure of welding spots under long-term vibration and the like, and cannot meet the higher requirements of future markets. Based on this, the industry is also exploring "conductive diaphragm" technology for directly preparing wires on the diaphragm body. Currently, a common approach to achieve high conductivity is to fill a high content (> 70%) of conductive filler in the polymer matrix. However, although this approach achieves low electrical resistance through high conductive filler content, too high a filler addition can result in a significant decrease in the flexibility, ductility of the composite. And the conductive filler is extremely easy to agglomerate due to the high surface energy of the conductive filler, has poor dispersibility in a polymer matrix, and is easy to generate interface stress concentration, so that the risk of cracking or separating a conductive layer from a vibrating diaphragm substrate occurs under the working condition of large-amplitude reciprocating bending vibration of the vibrating diaphragm. The choice of the polymer matrix is also very important, and if the selected matrix material and the loudspeaker diaphragm have poor chemical compatibility, the interface stability margin after long-term environmental aging is insufficient. Disclosure of Invention The invention aims to solve the technical problems of providing the conductive ink for the micro-speaker diaphragm, the preparation method thereof and the micro-speaker diaphragm, wherein the conductive ink has high flexibility, fatigue resistance and long-term environmental reliability matched with the micro-speaker diaphragm while improving the conductivity of the micro-speaker diaphragm, and can be well suitable for the application requirements of the micro-speaker. In order to solve the technical problems, the invention adopts a technical scheme that: A conductive ink for a micro-speaker diaphragm comprises 10-60wt% of conductive filler, 10-70wt% of matrix resin, 10-70wt% of dispersion medium, 0.1-5.0wt% of silane coupling agent, 0.2-5.0wt% of dispersing agent, 0.05-1.0 of defoamer, 0.05-2.0 of antioxidant and 0.05-1.5 of ultraviolet absorber; The conductive filler comprises nanowires with high length-diameter ratio; The matrix resin includes an acrylic system resin. In order to solve the technical problems, the invention adopts another technical scheme that: the preparation method of the conductive ink for the micro-speaker diaphragm comprises the following steps: Premixing a dispersion medium, a matrix resin, a defoaming agent, an antioxidant and an ultraviolet absorbent to obtain a stable mixed base material; Uniformly adding nanowire dispersion liquid into the mixed base material, then adding a dispersing agent to obtain conductive ink, and homogenizing; The conductive ink after the homogenization treatment is subjected to viscosity adjustment and filtration. In order to solve the technical problems, the invention adopts another technical scheme that: A micro-speaker diaphragm comprises the conductive ink for the micro-speaker diaphragm The invention has the beneficial effects that the conductive ink adopts the nano wire with high length-diameter ratio as the conductive filler, adopts the acrylic acid system resin as the matrix resin, and adds the antioxidant and the ultraviolet absorber as the anti-aging filler, the one-dimensional characteristic of the nano wire with high length-diameter ratio can lead the nano wire to realize mutual lap joint in a high polymer machine body, a three-dimensional conductive network is constructed, a conductive path with line-to-line is realized, the three-dimensional conductive network can obviously reduce the seepage threshold value of the conductive path on one hand, can realize extremely low impedance in a wider filler content range, particularly in a middle-low content range, and can realize reconstruction along with the stretching of the matrix on the other hand, and can maintain the integrity of the conductive path through the flexibility and the stretchability of the nano wire when the loudspeaker diaphragm vibrates greatly, thereby having excellent fatigue resistance; the acrylic system resin and the common vibrating diaphragm (such as ethylene-acrylic rubber AEM and acrylic rubber ACM) of the micro-speaker have similar molecular main chain or side chain structure (acrylic ester unit), the high chemic