Solvent-based conductive slurry, conductive elastomer and preparation method and application thereof

Abstract

The invention discloses a solvent-based conductive paste, a conductive elastomer and a preparation method and application thereof. The solvent-based conductive paste comprises the following components in parts by weight: 40-60 parts of solvent-based conductive material dispersion liquid and 40-60 parts of solvent-based resin, the mass ratio of a solvent-type conductive material in the solvent-type conductive material dispersion liquid is 5%-30%, and the solvent-type conductive material is a nano metal wire cleaned by DMF (Dimethyl Formamide); the solid content of the solvent type resin is 20%-50%. The nano metal wire cleaned by DMF is more uniformly dispersed in a resin matrix and has small overlap resistance, so that the conductive elastomer obtained by molding and drying the solvent type conductive slurry not only can maintain a good conductive path under the action of external force such as repeated bending and stretching, but also can maintain good conductive performance under long-term illumination, high temperature and high humidity; therefore, stable transmission of the current is realized, the service life of the product can be effectively prolonged, and the loudspeaker has a good application prospect in the field of loudspeakers.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible conductive materials, and in particular to a solvent-based conductive paste, a conductive elastomer, and a preparation method and application thereof. Background Art

[0002] With the rapid development of consumer electronic products in recent years, people have more demands for product diversification and adaptability. In previous products, the medium connecting the two electrodes was often a traditional metal wire. However, metal wires are heavy and not resistant to bending, which is not conducive to the development of electronic products towards lightweight and flexible directions. In addition, electronic products connected by metal wires are prone to connection failure under the action of vibration and external stress, which seriously affects the product's ability to resist vibration and stress. To solve the above problems, it is proposed to use lightweight, flexible and highly conductive elastic conductors to replace traditional metal wires, thereby broadening the portability and service life of electronic products and effectively reducing the impact of physical vibration and external stress on the electrical connection of products.

[0003] Currently, elastic conductors typically consist of an elastic matrix filled with a conductive material, with the conductive material forming a conductive path within the elastic matrix through overlapping connections. Silver nanowires (AgNWs) have important applications in flexible electronics, wearable devices, and conductive elastomers due to their high conductivity, excellent mechanical flexibility, and optical transmittance. However, AgNWs are typically coated with high-molecular-weight polyvinylpyrrolidone (PVP) as a stabilizer to prevent aggregation and control morphology. Furthermore, to obtain AgNWs with a high aspect ratio, higher molecular weight PVP is required to more effectively coat the silver crystal faces, inhibit lateral growth, and guide axial extension. This high-molecular-weight PVP is difficult to completely remove using traditional centrifugation or washing methods. Residual PVP not only hinders the uniform dispersion of AgNWs in the resin matrix but also introduces an insulating layer at the contact points of the nanowires, significantly increasing the overlapping resistance and reducing the overall conductive performance. Summary of the Invention

[0004] To solve the above problems, the present invention provides a solvent-based conductive paste, a conductive elastomer, and a preparation method and application thereof. The nanometal wires are heated and cleaned with N,N-dimethylformamide (DMF), which not only effectively removes the high molecular weight PVP on the surface of the nanometal wires (nanosilver wires); at the same time, the nanosilver wires after DMF cleaning have good compatibility with solvent-based resins, and a solvent-based conductive paste in which the nanoconductive material is uniformly dispersed can be obtained. The conductive elastomer obtained by molding and drying the solvent-based conductive paste has high conductivity with a low addition amount of nanoconductive material, and the bonding force between the nanoconductive material and the resin in the conductive elastomer is good, which is beneficial to the conductive stability of the conductive elastomer under stress. The conductive elastomer can be used to connect the external circuit and coil leads of the speaker, thereby improving the service life of the product.

[0005] Specifically, the following technical solutions are provided:

[0006] The first aspect of the present invention provides a solvent-based conductive paste, which comprises the following components in parts by weight: 40-60 parts of solvent-based conductive material dispersion, 40-60 parts of solvent-based resin; wherein,

[0007] The mass percentage of the solvent-based conductive material in the solvent-based conductive material dispersion is 5%-30%, and the solvent-based conductive material is a nanometal wire that has been cleaned with N,N-dimethylformamide;

[0008] The solid content of the solvent-based resin is 20%-50%.

[0009] The high molecular weight PVP on the surface of currently commercially available or homemade silver nanowires is difficult to remove, which affects the dispersion and bonding resistance of the silver nanowires in the resin matrix. In addition, the compatibility between the silver nanowires and the resin is poor, and phase separation is prone to occur, which greatly affects the conductivity of the prepared elastic conductor and the conductive stability under stress. To address the above-mentioned problems, the present invention uses a specific solvent, DMF, to heat and clean commercially available or homemade nanosilver wires. On the one hand, the formyl group of DMF and the pyrrolidone ring of the PVP side chain are partially cross-linked under heating conditions, thereby effectively removing the high molecular weight PVP on the surface of the nanometal wires (nanosilver wires), which is beneficial to improving the dispersion of the nanosilver wires in the resin and effectively reducing the overlap resistance between the nanosilver wires in the resin. At the same time, the nanosilver wires after DMF cleaning treatment have good compatibility with the solvent-based resin, and a solvent-based conductive paste with a uniform dispersion of nanoconductive material can be obtained. Therefore, an elastic conductor with extremely low impedance can be obtained with a low amount of nanosilver wire added. In addition, the prepared elastic conductor has a strong bonding force between the nanosilver wires and the resin, and maintains high conductivity and good stability under stress such as bending and stretching.

[0010] Furthermore, the mass percentage of the solvent-based conductive material in the solvent-based conductive material dispersion is more preferably 5%-20%, for example, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc.

[0011] Furthermore, the solvent-based conductive material dispersion includes a solvent-based conductive material and a solvent, and the solvent includes but is not limited to DMF.

[0012] Furthermore, the N,N-dimethylformamide cleaning treatment is performed under heating conditions, and the heating temperature is 100-150° C. Specifically, the preparation of the nanometal wires after the N,N-dimethylformamide cleaning treatment includes the following steps: centrifuging a commercially available or homemade nanometal wire dispersion to remove the supernatant, adding DMF, mixing and shaking under heating conditions, and then centrifuging to remove the supernatant. The mixing, shaking, and centrifuging steps are repeated 2-3 times to obtain the nanometal wires after the N,N-dimethylformamide cleaning treatment.

[0013] Furthermore, the metal nanowires include but are not limited to silver nanowires. Preferably, the silver nanowires have an aspect ratio of 500-2000.

[0014] More preferably, the aspect ratio of the silver nanowire is 1000-1500, such as 1000, 1100, 1200, 1300, 1400, 1500, etc., including but not limited to the aspect ratios listed above, and more preferably 1000-1300.

[0015] The aspect ratio of the silver nanowires affects the formation of the conductive network within the conductive elastomer and the number of overlapping points of the silver nanowires within the conductive elastomer, thereby affecting the stability of the conductive network formed by the silver nanowires within the conductive elastomer under stress. When the conductive elastomer is bent or stretched, the overlapping between the conductive silver nanowires inside may be disconnected, resulting in a decrease in conductivity. In theory, the larger the aspect ratio of the silver nanowires, the more overlapping points of the silver nanowires in the conductive network formed, and the smaller the impact on the conductivity of the conductive elastomer under a certain stress. However, in actual preparation, silver nanowires with a larger aspect ratio are more likely to agglomerate and difficult to evenly disperse in the elastic matrix. In addition, the larger the aspect ratio of the silver nanowires, the larger the specific surface area, and the greater the impact of external environmental factors on their conductivity. Based on this, in order to obtain a conductive elastomer with high conductivity, good conductive stability under stress, and stable current transmission under conditions such as light, high humidity, and high heat, the aspect ratio of the silver nanowires needs to be controlled within an appropriate range, for example, 1000-1500, more preferably 1000-1300.

[0016] In some preferred embodiments, when the length of the silver nanowire is about 18 nm, the cross-sectional diameter of the silver nanowire is 18 nm-50 nm.

[0017] Furthermore, the solvent-based resin is a solvent-based polyurethane resin selected from one or more of polyether polyurethane, polyester polyurethane, and polyurea polyurethane. Using the solvent-based polyurethane resin as the matrix of the conductive elastomer imparts good flexibility to the conductive elastomer. Furthermore, the solvent-based polyurethane resin exhibits good compatibility with the DMF-modified metal nanowires, thereby improving the conductivity of the conductive elastomer and its conductive stability under stress.

[0018] In some preferred embodiments, the solvent-based resin is polyether polyurethane purchased from Guangdong 137 Chemical Technology Co., Ltd., with a resin model of MR-326 and a solid content of 35%.

[0019] Furthermore, the solvent-based conductive paste further comprises 0.5-1.5 parts of a defoaming agent to remove bubbles in the solvent-based conductive paste during the molding process, so that the prepared solvent-based conductive elastomer is continuous and uniform.

[0020] In some preferred embodiments, the defoaming agent is a nonionic polyether modified silicon defoaming agent purchased from Dongguan Guozhong New Materials Research Institute Co., Ltd., and the defoaming agent model is DU-1209.

[0021] Furthermore, the viscosity of the solvent-based conductive paste is 3000-8000 cP, for example, 3000 cP, 4000 cP, 5000 cP, 6000 cP, 7000 cP, 8000 cP, etc., including but not limited to the viscosity values ​​listed above. To facilitate coating and ensure uniformity of the prepared solvent-based conductive elastomer, the viscosity of the solvent-based conductive paste needs to be controlled within a suitable range, for example, 3000-8000 cP.

[0022] A second aspect of the present invention provides a solvent-based conductive elastomer, which is obtained by molding and drying the solvent-based conductive paste described in the first aspect.

[0023] Furthermore, the forming method includes but is not limited to coating on a substrate.

[0024] A third aspect of the present invention provides a method for preparing the solvent-based conductive elastomer according to the second aspect, comprising the following steps:

[0025] S1. Mix the components according to the formula to obtain a solvent-based conductive paste;

[0026] S2. Coating the solvent-based conductive paste on the surface of a substrate, and drying the solvent-based conductive elastomer on the surface of the substrate.

[0027] Furthermore, in step S1, the solvent-based conductive paste comprises the following components in parts by weight: 40-60 parts of solvent-based conductive material dispersion, 40-60 parts of solvent-based resin, and 0.5-1.5 parts of defoaming agent.

[0028] Furthermore, the solvent-based conductive material dispersion is a solvent-based nanosilver wire dispersion; the preparation of the solvent-based nanosilver wire dispersion comprises the following steps:

[0029] (1) centrifuging the silver nanowire dispersion to remove the supernatant and retaining the silver nanowire sediment at the bottom;

[0030] (2) adding DMF to the nano silver wire deposition solution prepared in step (1), sealing the solution, shaking it in an oven at 100-150° C., and centrifuging to remove the supernatant;

[0031] (3) Repeat step (2) 2-3 times to obtain a silver nanowire deposition solution after washing with DMF;

[0032] (4) adding DMF to the nano silver wire deposition liquid prepared in step (3) after being cleaned with DMF to obtain the solvent-based nano silver wire dispersion liquid.

[0033] Furthermore, in step (1), the mass percentage of the silver nanowires in the silver nanowire deposition solution is 10%-40%, more preferably 10%-20%.

[0034] In some preferred embodiments, in step (1), the centrifugal speed is 3800 r / min and the time is 8 min; in step (2), the oscillation treatment is performed in an oscillator and the treatment time is 10 min.

[0035] Furthermore, in step S1, the mixing step is carried out in a homogenizer, preferably, homogenizing for 10 minutes in a homogenizer at a vacuum of -99 kPa and a speed of 1000 r / min.

[0036] Furthermore, in step S2, the coating thickness is 100 μm-200 μm, and the thickness of the corresponding solvent-based conductive elastomer after drying is 5 μm-15 μm.

[0037] Furthermore, in step S2, the drying temperature is 120-180°C, and the drying time is 5-30 minutes.

[0038] A fourth aspect of the present invention provides a speaker comprising the solvent-based conductive elastomer described in the second aspect or the solvent-based conductive elastomer prepared by the preparation method described in the third aspect, wherein the solvent-based conductive elastomer is used to connect the external circuit of the speaker with the coil lead.

[0039] The solvent-based conductive elastomer can be obtained by in-situ molding and drying the solvent-based conductive slurry on the surface of the diaphragm or the centering support of the speaker.

[0040] Furthermore, the solvent-based conductive elastomer comprises silver nanowires, and the aspect ratio of the silver nanowires is preferably 1000-1300.

[0041] In a loudspeaker, if the resistance of the elastic conductor used to connect the speaker's external circuit to the coil leads changes significantly due to environmental conditions, it can lead to signal transmission loss or distortion. The resistance of the solvent-based conductive elastomer prepared by the present invention first decreases and then increases with the increase in the aspect ratio of the nanosilver wires, and the impedance change rate increases with the increase in aspect ratio under conditions of light, high temperature, and high humidity. This is because the thinner the nanosilver wire morphology, the more significant the impact of the external environment on the conductive properties of the conductive elastomer. Therefore, to obtain a conductive elastomer with high conductivity, good conductive stability under stress, and stable current transmission under conditions such as light, high humidity, and high heat, it is preferable to control the aspect ratio of the nanosilver wires within the range of 1000-1300.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The present invention provides a solvent-based conductive paste that can be in-situ molded on the surface of any substrate to prepare a conductive elastomer. The prepared conductive elastomer not only has good adhesion to the substrate; more importantly, due to the good compatibility of the nanometal wires and the resin after DMF cleaning treatment, the uniform dispersion of the nanometal wires in the resin and the improvement of the interfacial bonding strength between the two can be promoted, and the high molecular weight PVP on the surface of the nanometal wires can be effectively removed during the DMF heating and cleaning process. As a result, the conductive elastomer prepared by the present invention can achieve high conductivity with a low amount of conductive material added, and can always maintain stable high conductivity under stress such as bending and stretching. It can also maintain good conductive properties under long-term light exposure, high temperature, and high humidity, thereby achieving stable current transmission.

[0044] The present invention provides a method for preparing the above-mentioned solvent-based conductive elastomer, which can obtain the conductive elastomer of the desired shape through simple mixing, coating and drying. Industrial production can be achieved through printing, which is simple to operate and highly efficient.

[0045] The present invention also provides a speaker, which uses the above-mentioned solvent-based conductive elastomer as a wire to connect the external circuit of the speaker and the coil lead, thereby improving the performance and service life of the speaker under the influence of vibration, external stress, etc. DETAILED DESCRIPTION

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the relevant listed items. The term "includes" or "comprising" described in the present invention means that in addition to the components described, it may also include or contain other components. The term "includes" or "comprising" described in the present invention may also be replaced by the closed form "for" or "consisting of..."

[0047] The present invention will be further described below with reference to specific examples so that those skilled in the art can better understand the present invention and implement it, but the examples are not intended to limit the present invention.

[0048] Example 1

[0049] This embodiment provides a solvent-based conductive material dispersion, a conductive elastomer, and a preparation method thereof. The specific operations are as follows:

[0050] (1) Preparation of solvent-based conductive material dispersion:

[0051] Centrifuge a low-concentration aqueous dispersion of silver nanowires (average length of approximately 18 μm, diameter of 18 nm, aspect ratio of 1000). Remove the supernatant and retain the high-concentration silver nanowire deposit at the bottom. Mix DMF solvent into the high-concentration silver nanowire deposit. Seal the lid to ensure a tight seal and mix thoroughly in a 120°C oven using a shaker. Remove and centrifuge to obtain the high-concentration silver nanowire deposit. Discard the supernatant. Repeat this process three times to obtain the DMF-washed nanowire deposit.

[0052] The nano-metal wire deposition liquid obtained after DMF washing was added with DMF solvent according to calculation and shaken evenly with a shaker to obtain a 20 wt % solvent-based nano-silver wire dispersion.

[0053] (2) 59 parts of the solvent-based conductive material dispersion prepared above, 40 parts of a solvent-based resin (Guangdong Yisanqi Chemical Technology Co., Ltd., resin model MR-326, solid content 35%) and 1 part of a defoamer (Dongguan Guozhong New Materials Research Institute Co., Ltd., defoamer model DU-1209) were added to a tank in sequence, and stirred evenly using a homogenizer to obtain a solvent-based conductive slurry.

[0054] (3) The solvent-based conductive paste is coated on the surface of a substrate, and the substrate is removed after drying to obtain a solvent-based conductive elastomer A1.

[0055] 1. Study the effects of different morphologies of metal conductive materials on the resistance and bending properties of conductive elastomers

[0056] The nanosilver wires in the solvent-based conductive paste were replaced by equal amounts of spherical nanosilver powder and nanosilver flakes, respectively. Other operations were consistent with the preparation of solvent-based conductive elastomer A1, and corresponding conductive elastomers B1 and B2 were prepared.

[0057] The resistance and bending properties of the conductive elastomers containing nanosilver materials with different morphologies were tested. The specific testing process is as follows:

[0058] Conductive elastomers A1, B1, and B2 were cut into specimens with a length of 50 mm, a width of 5 mm, and a thickness of 20 μm. The impedance values ​​at both ends of the conductive elastomer specimens were tested using a multimeter. Different specimens were bent 180° at one-third and two-thirds of the length of the entire conductive elastomer specimen. After being bent for different numbers of times (100, 300, 500, and 1000), the impedance values ​​at both ends were tested using a multimeter to observe the impedance changes.

[0059] The test results are shown in Table 1 below:

[0060] Table 1

[0061]

[0062]

[0063] As can be seen from Table 1, compared with the conductive elastomer prepared from spherical or flaky conductive materials, the conductive elastomer prepared using the same amount of nano-silver wires in the present invention has significantly lower resistance and exhibits better conductive stability after bending.

[0064] 2. Study the effect of DMF cleaning of nanosilver wires at different temperatures on the resistance and bending properties of conductive elastomers

[0065] The silver nanowires were cleaned with DMF at room temperature. Other operations were consistent with the preparation of solvent-based conductive elastomer A1 to obtain the corresponding conductive elastomer C1.

[0066] The resistance and bending properties of the conductive elastomers containing nanosilver materials with different morphologies were tested using the same test methods as above. The test results are shown in Table 2 below:

[0067] Table 2

[0068]

[0069] Example 2

[0070] This embodiment provides a solvent-based conductive material dispersion, a conductive elastomer, and a preparation method thereof. The only difference from Example 1 is that the aspect ratio of the silver nanowires is different. The silver nanowires used in this embodiment have an average length of approximately 18 μm, a diameter of 16 nm, and an aspect ratio of 1125. The other operations are the same, and the corresponding solvent-based conductive elastomer A2 is prepared.

[0071] Example 3

[0072] This embodiment provides a solvent-based conductive material dispersion, a conductive elastomer, and a preparation method thereof. The only difference from Example 1 is that the aspect ratio of the silver nanowires is different. The silver nanowires used in this embodiment have an average length of approximately 18 μm, a diameter of 14 nm, and an aspect ratio of 1285. All other operations are consistent, and the corresponding solvent-based conductive elastomer A3 is prepared.

[0073] Example 4

[0074] This embodiment provides a solvent-based conductive material dispersion, a conductive elastomer, and a preparation method thereof. The only difference from Example 1 is that the aspect ratio of the silver nanowires is different. The silver nanowires used in this embodiment have an average length of approximately 18 μm, a diameter of 12 nm, and an aspect ratio of 1500. Other operations are the same, and the corresponding solvent-based conductive elastomer A4 is prepared.

[0075] Test Example 1

[0076] The solvent-based conductive elastomers A1-A4 prepared in Examples 1-4 were cut into samples with a length of 50 mm, a width of 5 mm, and a thickness of 20 μm. The resistance and resistance after different treatments (bending, elongation, and elongation recovery) were tested. The specific operation is as follows:

[0077] Conventional resistance test: Use a multimeter to test the impedance value at both ends of the conductive elastomer;

[0078] Bending resistance test: Bend the conductive elastomer sample 180° at one-third and two-thirds of its length. Bend it for different times (100, 300, 500, 1000) and use a multimeter to measure the impedance at both ends to observe the impedance change.

[0079] Elongation resistance test: Use insulated tweezers to stretch the ends of the conductive elastomer sample horizontally. After stretching to different lengths, use a multimeter to measure the impedance value at both ends and observe the impedance change.

[0080] Resistance test after elongation recovery: After the elongation test, the conductive elastomer is restored and the impedance change is tested again to compare the impedance stability before and after stretching.

[0081] The test results are shown in Table 3 below:

[0082] Table 3

[0083]

[0084]

[0085] As can be seen from Table 3, when other conductive paste formula conditions remain unchanged, as the diameter of the nanosilver wire decreases until the diameter drops to 14nm, the impedance values ​​corresponding to various tests of the sample decrease with the decrease in diameter (increase in aspect ratio); however, when the diameter of the nanosilver wire continues to decrease to 12nm (aspect ratio reaches 1500), the resistance of the conductor increases instead, especially the resistance under bending and elongation conditions increases significantly. This shows that controlling the aspect ratio of the nanosilver wire within a suitable range is more conducive to the conductive stability of the conductive elastomer under stress, and is more suitable for providing stable current transmission in a high-frequency vibration environment.

[0086] Test Example 2

[0087] The solvent-based conductive elastomers A1-A4 prepared in the above Examples 1-4 were cut into samples with a length of 50 mm, a width of 5 mm, and a thickness of 20 μm, and stored under different environments (xenon lamp irradiation, high-temperature baking at 90°C, and high-temperature baking at 70% humidity and 70°C) for 30 days. The conductive properties of the conductive elastomers after storage were tested, and the impedance change rate of the samples before and after storage was calculated (impedance change rate = (normal resistance - resistance after test) / normal resistance × 100%) to examine the durability of the conductive elastomers in static harsh environments.

[0088] The test and calculation results are shown in Table 4 below:

[0089] Table 4

[0090]

[0091] Table 4 shows that as the aspect ratio of the silver nanowires increases, the rate of change of the sample's impedance in the various environments described above increases. Furthermore, the impedance change rate increases significantly when the aspect ratio increases from 1000 to 1500. This indicates that the more slender the silver nanowires, the more pronounced the impact of the external environment on the conductive properties of the conductive elastomer. Tables 3 and 4 indicate that silver nanowires with an aspect ratio of 1000-1300 are preferred for achieving high conductivity, good conductive stability under stress, and stable current transmission under conditions of light, high humidity, and high heat.

[0092] The above-described embodiments are merely preferred examples for the purpose of fully illustrating the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

Claims

1. A solvent-based conductive paste, characterized in that: The invention comprises the following components in parts by weight: 40-60 parts of solvent-based conductive material dispersion, 40-60 parts of solvent-based resin; The mass percentage of the solvent-based conductive material in the solvent-based conductive material dispersion is 5%-30%, and the solvent-based conductive material is a nanometal wire that has been cleaned with N,N-dimethylformamide; The solid content of the solvent-based resin is 20%-50%.

2. The solvent-based conductive paste according to claim 1, characterized in that: The preparation of the nanometal wires after the N,N-dimethylformamide cleaning treatment comprises the following steps: (1) centrifuging the nanowire dispersion to remove the supernatant and retaining the nanowire sediment at the bottom; (2) adding N,N-dimethylformamide to the nanometal wire deposition liquid prepared in step (1), sealing, shaking under heating conditions, and centrifuging to remove the supernatant to obtain a nanometal wire deposition liquid after preliminary cleaning; the heating temperature is 100-150° C.; (3) Repeat step (2) 2-3 times to obtain the nanometal wires after washing with N,N-dimethylformamide.

3. The solvent-based conductive paste according to claim 1 or 2, characterized in that: The metal nanowires include silver nanowires; the aspect ratio of the silver nanowires is 500-2000.

4. The solvent-based conductive paste according to claim 3, characterized in that: The aspect ratio of the silver nanowire is 1000-1500.

5. The solvent-based conductive paste according to claim 1, characterized in that: The solvent-based resin is a solvent-based polyurethane resin selected from one or more of polyether polyurethane, polyester polyurethane, and polyurea polyurethane; The solvent in the solvent-based resin is selected from one or more of ester solvents and alcohol solvents; the ester solvent includes ethyl acetate and butyl acetate, and the alcohol solvent includes ethanol and isopropanol.

6. The solvent-based conductive paste according to claim 1, characterized in that: The solvent-based conductive paste further comprises 0.5-1.5 parts of a defoaming agent; The viscosity of the solvent-based conductive paste is 3000-8000 cP.

7. A solvent-based conductive elastomer, characterized in that: The solvent-based conductive elastomer is obtained by molding and drying the solvent-based conductive paste according to any one of claims 1 to 6.

8. A method for preparing the solvent-based conductive elastomer according to claim 7, characterized in that: The following steps are involved: S1. Mix the components according to the formula to obtain a solvent-based conductive paste; S2. Coating the solvent-based conductive paste on the surface of a substrate, and drying the solvent-based conductive elastomer on the surface of the substrate.

9. The preparation method according to claim 8, characterized in that In step S1, the mixing step is performed in a homogenizer; In step S2, the drying temperature is 120-180°C, and the drying time is 5-30 minutes.

10. A speaker, characterized in that: A solvent-based conductive elastomer according to claim 7 or a solvent-based conductive elastomer prepared by the preparation method according to claim 8 or 9, wherein the solvent-based conductive elastomer is used to connect the external circuit of the speaker and the coil lead; The solvent-based conductive elastomer is obtained by in-situ molding and drying the solvent-based conductive slurry on the surface of the diaphragm or the centering support of the loudspeaker.

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