Epoxy resin conductive paste for preparing electroforming cathode core mold and preparation method of epoxy resin conductive paste

Abstract

The invention relates to the technical field of conductive paste, in particular to epoxy resin conductive paste for preparing an electroforming cathode core mold and a preparation method of the epoxy resin conductive paste, and the epoxy resin conductive paste comprises epoxy resin A glue, flaky silver-coated copper powder, granular silver-coated copper powder, crystalline flake graphite and a curing agent; wherein the mass ratio of the epoxy resin A glue to the flaky silver-coated copper powder to the granular silver-coated copper powder to the crystalline flake graphite to the curing agent is (1-1.5): (2-5): (2-5): (1-2.5): 1, the average particle size of the flaky silver-coated copper powder is 10 [mu] m, the average particle size of the granular silver-coated copper powder is 4 [mu] m-5 [mu] m, and the average particle size of the crystalline flake graphite is 30 [mu] m. The prepared epoxy resin conductive slurry is poured into a forming mold and cured, a core mold is prepared after demolding, the service life of the cathode core mold in the electroforming process can be prolonged, and the electroforming precision can be improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of conductive materials, and in particular to an epoxy resin conductive slurry for preparing an electroforming cathode core mold and a preparation method thereof. Background Art

[0002] In the field of electroforming technology, conductive slurry is the key material for preparing the electroforming cathode core mold. The formability and conductive stability of the core mold directly affect the forming accuracy of metal parts during the electroforming process.

[0003] At present, the conductive paste used in the electroforming cathode core mold is silver particle / polydimethylsiloxane (PDMS / Ag) conductive paste. PDMS / Ag conductive paste is composed of silver particle filler and polydimethylsiloxane (PDMS) matrix. During electroforming, the PDMS / Ag core mold has the problem of low PDMS stiffness and easy deformation during deposition.

[0004] However, epoxy resin conductive paste is considered to be one of the promising alternatives for the preparation of electroforming cathode core molds. Compared with PDMS conductive paste, epoxy resin conductive paste has obvious advantages in preparation cost, rigidity and compatibility. Therefore, it is necessary to develop an epoxy resin conductive paste for the preparation of electroforming cathode core molds to improve its forming accuracy, conductive stability and service life.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] The purpose of the present disclosure is to provide an epoxy resin conductive paste for preparing an electroforming cathode core mold and a preparation method thereof, thereby solving the problem of easy deformation of the PDMS / Ag core mold at least to a certain extent.

[0007] According to one aspect of the present disclosure, there is provided an epoxy resin conductive paste for preparing an electroforming cathode core mold, the epoxy resin conductive paste comprising: epoxy resin A glue, flaky silver-coated copper powder, granular silver-coated copper powder, flake graphite and a curing agent;

[0008] Among them, the mass ratio of the epoxy resin A glue, the flaky silver-coated copper powder, the granular silver-coated copper powder, the flake graphite and the curing agent is (1-1.5): (2-5): (2-5): (1-2.5): 1, the average particle size of the flaky silver-coated copper powder is 10 μm, the average particle size of the granular silver-coated copper powder is 4 μm-5 μm, and the average particle size of the flake graphite is 30 μm.

[0009] According to one embodiment of the present disclosure, the epoxy resin conductive paste also includes: a plasticizer, an anti-settling agent and a defoaming agent, and the mass ratio of the plasticizer, anti-settling agent, defoaming agent and the epoxy resin A glue is 0.4: (0.05-0.125): (0.04-0.1): (1-1.5).

[0010] According to one embodiment of the present disclosure,

[0011] The plasticizer is one or more of dioctyl terephthalate, dibutyl phthalate, and dioctyl phthalate;

[0012] The anti-settling agent is one of polyolefin wax and polyamide wax;

[0013] The defoamer is an organosilicon defoamer.

[0014] According to one embodiment of the present disclosure,

[0015] The epoxy resin A glue is E-44;

[0016] The curing agent is epoxy resin B glue.

[0017] According to another aspect of the present disclosure, a method for preparing an epoxy resin conductive paste for preparing an electroforming cathode core mold is provided, which is used to prepare the epoxy resin conductive paste according to any one of claims 1 to 4, characterized in that the preparation method comprises the following steps:

[0018] Step 1: Evenly mix flaky silver-coated copper powder, granular silver-coated copper powder, flake graphite and anhydrous ethanol to obtain a conductive filler suspension, wherein the mass ratio of the flaky silver-coated copper powder, granular silver-coated copper powder, flake graphite and anhydrous ethanol is (2-5): (2-5): (1-2.5): (2.5-6);

[0019] Step 2: Mixing the curing agent and the conductive filler suspension to obtain a first mixture, heating the first mixture to evaporate the anhydrous ethanol, and the mass ratio of the curing agent to the flake graphite is 1: (1-2.5);

[0020] Step 3: adding epoxy resin A glue to the first mixture after evaporation of anhydrous ethanol, stirring and mixing thoroughly to obtain a second mixture, wherein the mass ratio of the epoxy resin A glue to the curing agent is in the range of (1-1.5):1;

[0021] Step 4: removing bubbles from the second mixture to obtain the epoxy resin conductive paste.

[0022] According to one embodiment of the present disclosure, before mixing the curing agent and the conductive filler suspension to obtain the first mixed material, the preparation method further includes:

[0023] The plasticizer is added into the curing agent and stirred evenly to modify the curing agent, wherein the mass ratio of the plasticizer to the curing agent is 0.4:1.

[0024] According to one embodiment of the present disclosure, before adding epoxy resin A glue to the first mixed material after the anhydrous ethanol is evaporated, the method further includes:

[0025] Add the anti-settling agent to the first mixture and stir evenly. The mass ratio of the anti-settling agent to the curing agent is (0.05-0.125):1.

[0026] According to one embodiment of the present disclosure, removing bubbles in the second mixed material includes:

[0027] Adding a defoamer to the second mixed material and stirring evenly, the mass ratio of the defoamer to the curing agent is (0.04-0.1):1;

[0028] The mixture of the second mixed material and the defoaming agent is vacuumed to remove air bubbles therein.

[0029] According to one embodiment of the present disclosure, the preparation method further comprises:

[0030] The epoxy resin conductive paste is poured into the forming mold and cured, and the electroforming cathode core mold is formed after demoulding.

[0031] The epoxy resin conductive paste for preparing the electroforming cathode core mold provided by the embodiment of the present disclosure includes epoxy resin A glue, flaky silver-coated copper powder, granular silver-coated copper powder, flake graphite and curing agent; the mass ratio of epoxy resin A glue, flaky silver-coated copper powder, granular silver-coated copper powder, flake graphite and curing agent is (1-1.5): (2-5): (2-5): (1-2.5): 1. By using epoxy resin A glue and curing agent as the matrix of the conductive paste, the rigidity of the cathode core mold is improved, and the problem that the rigidity of the cathode core mold of the PDMS matrix is ​​low and easy to deform during the deposition process is solved. In addition, by doping flake graphite into the flaky silver-coated copper powder and the granular silver-coated copper powder, the conductivity of the epoxy resin conductive paste can be improved, thereby improving the conductive performance of the cathode core mold. By adding a plasticizer to the epoxy resin matrix, the fluidity of the epoxy resin matrix can be improved, thereby ensuring the forming accuracy during the forming of the electroforming cathode core mold. By adding an anti-settling agent to the conductive slurry, the conductive filler can be prevented from settling, thereby improving the uniformity of the conductivity of the electroforming cathode core mold.

[0032] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0034] Figure 1 A physical picture of a cathode core mold prepared with epoxy conductive paste provided in Example 1, Example 2 and Example 3 of the present disclosure;

[0035] Figure 2 This is a surface microscopic morphology of the cathode core mold prepared in Example 1 of the present disclosure;

[0036] Figure 3 This is a cross-sectional microscopic morphology image of the cathode core mold prepared in Example 1 of the present disclosure;

[0037] Figure 4 The phase diagram of the cathode core mold prepared in Example 1 of the present disclosure;

[0038] Figure 5 A working principle diagram of electroforming provided by the present disclosure;

[0039] Figure 6 Nyquist plot and electronic resistivity value of the cathode core mold prepared in Example 1 of the present disclosure in a copper sulfate solution. DETAILED DESCRIPTION

[0040] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted.

[0041] The terms "a", "an", and "the" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusion and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second", and "third", etc. are used merely as labels and are not intended to limit the quantity of their objects.

[0042] In the field of electroforming technology, conductive paste is the key material for preparing electroforming cathode core molds. The formability and conductive stability of the core mold directly affect the forming accuracy of metal parts during the electroforming process. At present, the conductive paste for electroforming cathode core molds is mainly composed of silver particle filler and polydimethylsiloxane (PDMS) matrix. However, PDMS / Ag core molds have the following disadvantages in electroforming: PDMS and Ag are expensive and difficult to promote on a large scale; PDMS has low rigidity and is easy to deform during deposition; Ag particles on the surface of PDMS core molds are easy to fall off, resulting in a low service life.

[0043] In order to solve the above technical problems, the exemplary embodiment of the present disclosure first provides an epoxy resin conductive paste for preparing an electroforming cathode core mold, the epoxy resin conductive paste comprising: epoxy resin A glue, flaky silver-coated copper powder, granular silver-coated copper powder, flake graphite and curing agent. Among them, the mass ratio of epoxy resin A glue, flaky silver-coated copper powder, granular silver-coated copper powder, flake graphite and curing agent is (1-1.5): (2-5): (2-5): (1-2.5): 1, the average particle size of the flaky silver-coated copper powder is 10μm, the average particle size of the granular silver-coated copper powder is 4μm-5μm, and the average particle size of the flake graphite is 30μm.

[0044] The epoxy resin conductive paste for preparing the electroforming cathode core mold provided by the embodiment of the present disclosure includes epoxy resin A glue, flaky silver-coated copper powder, granular silver-coated copper powder, flake graphite and curing agent; the mass ratio of epoxy resin A glue, flaky silver-coated copper powder, granular silver-coated copper powder, flake graphite and curing agent is (1-1.5): (2-5): (2-5): (1-2.5): 1. By using epoxy resin A glue and curing agent as the matrix of the conductive paste, the rigidity of the cathode core mold is improved, and the problem that the rigidity of the cathode core mold of the PDMS matrix is ​​low and easy to deform during the deposition process is solved. In addition, by doping flake graphite into the flaky silver-coated copper powder and the granular silver-coated copper powder, the problem of small contact area and poor conductivity between the conductive fillers is solved, the conductivity of the epoxy resin conductive paste is improved, and then the conductive performance of the cathode core mold is improved.

[0045] Furthermore, the epoxy resin conductive paste for preparing the electroforming cathode core mold provided in the embodiment of the present disclosure may also include: plasticizer, anti-settling agent and defoaming agent, and the mass ratio of plasticizer, anti-settling agent, defoaming agent and epoxy resin A glue is 0.4: (0.05~0.125): (0.04~0.1): 1.

[0046] The plasticizer is one or more of dioctyl terephthalate, dibutyl phthalate and dioctyl phthalate. The anti-settling agent is one of polyolefin wax and polyamide wax. The defoamer is an organosilicon defoamer.

[0047] By adding plasticizers to the epoxy resin matrix, the poor fluidity of the epoxy resin matrix can be improved, thereby ensuring the forming accuracy of the electroforming cathode core mold. By adding anti-settling agents to the conductive paste, the stability of the epoxy resin conductive paste is improved, the problem of easy sedimentation of the conductive filler is solved, and the conductivity of the electroforming cathode core mold is more uniform.

[0048] In some embodiments, epoxy resin A glue is E-44, and the curing agent is epoxy resin B glue. It is understood that in practical applications, epoxy resin A glue is not limited to E-44, for example, epoxy resin A glue can also be E-51, etc.

[0049] The epoxy resin conductive paste for preparing the electroforming cathode core mold and the preparation method thereof provided in the embodiments of the present disclosure are described below through some embodiments:

[0050] Example 1

[0051] The epoxy resin conductive paste includes: epoxy resin A glue, flaky silver-coated copper conductive powder, spherical silver-coated copper conductive powder, doped flake graphite, dibutyl phthalate, epoxy resin B glue, polyolefin wax, and silicone defoamer. Among them, the mass of epoxy resin A glue, flaky silver-coated copper powder, spherical silver-coated copper powder, doped flake graphite, dioctyl terephthalate, epoxy resin B glue, polyamide wax, and silicone defoamer are 1:2:2:1:0.4:1:0.05:0.04 respectively.

[0052] The preparation method of the epoxy resin conductive paste is as follows, and the contents of the components during the preparation are: epoxy resin A glue, flaky silver-coated copper powder, spherical silver-coated copper powder, doped flake graphite, dioctyl terephthalate, epoxy resin B glue, polyamide wax, and silicone defoaming agent are 10g, 20g, 20g, 10g, 4g, 10g, 0.5g, and 0.4g, respectively.

[0053] Step 1: Disperse flake graphite, flaky conductive silver-coated copper powder, and granular conductive silver-coated copper powder in a beaker containing 25 g of anhydrous ethanol in proportion, and mechanically stir at 350 r / min for 1 hour to obtain a conductive filler suspension;

[0054] Step 2: Pour dioctyl terephthalate into epoxy resin B glue and stir evenly to obtain modified epoxy resin B glue, then pour the conductive filler suspension into the modified epoxy resin B glue, mechanically stir at 450r / min for 15min to obtain a first mixture, heat the first mixture in an oven at 50°C to slowly evaporate the anhydrous ethanol;

[0055] Mixing the first mixed material after the anhydrous ethanol is volatilized with the polyamide wax, and stirring until uniform;

[0056] Step 3: Add epoxy resin A glue to the mixture of the first mixed material and the polyamide wax, and stir and mix thoroughly until uniform, to obtain a second mixed material;

[0057] Adding the organosilicon defoamer to the second mixed material and stirring until uniform;

[0058] Step 4: Move the mixture of the second mixed material and the silicone defoamer to a vacuum drying oven, evacuate the mixture at room temperature for 10 to 30 minutes to remove bubbles inside the mixture, and obtain the graphite-doped silver-copper filler epoxy resin conductive paste.

[0059] The epoxy resin conductive slurry is poured into a cylindrical glass mold. After the conductive slurry completely fills the stainless steel mold, it is moved to an oven and kept at 110°C for 40 minutes to solidify and form. After cooling to room temperature, the conductive filler epoxy resin is demoulded from the original stainless steel mold to obtain a cathode core mold. Figure 1 As shown. After testing, the conductive filler is evenly dispersed in the epoxy resin matrix (such as Figure 2-Figure 4 shown).

[0060] See also Figure 5 The electroforming equipment used for the electroforming cathode core mold may also include an anode 3, a power supply assembly 1 and an electroforming liquid container 4. The anode 3 and the cathode core mold 2 are respectively connected to the power supply assembly 1. The electroforming liquid container 4 contains an electroforming liquid. The anode 3 and the cathode core mold 2 are arranged in the electroforming liquid container 4. This core mold is used as the cathode in the electroforming process. After testing, the conductivity of the core mold in the copper sulfate solution can reach 0.16S·m -1 (like Figure 6 shown).

[0061] Example 2

[0062] The epoxy resin conductive paste includes epoxy resin A glue, flaky silver-coated copper conductive powder, spherical silver-coated copper conductive powder, doped flake graphite, dibutyl phthalate, epoxy resin B glue, polyolefin wax, and silicone defoamer. Among them, the mass ratio of epoxy resin A glue, flaky silver-coated copper conductive powder, spherical silver-coated copper conductive powder, doped flake graphite, dibutyl phthalate, epoxy resin B glue, polyolefin wax, and silicone defoamer is 1:3:3:1.5:0.4:1:0.075:0.06.

[0063] The preparation method of the epoxy resin conductive paste is as follows, and the content of each component in the preparation method: the masses of epoxy resin A glue, flaky silver-coated copper conductive powder, spherical silver-coated copper conductive powder, doped flake graphite, dibutyl phthalate, epoxy resin B glue, polyolefin wax, and silicone defoaming agent are 10g, 30g, 30g, 15g, 4g, 10g, 0.75g, and 0.6g, respectively.

[0064] Step 1: Disperse flake graphite, flaky conductive silver-coated copper powder, and granular conductive silver-coated copper powder in a beaker containing 37.5 g of anhydrous ethanol according to the above proportions, and mechanically stir at 350 r / min for 1 hour to obtain a conductive filler suspension;

[0065] Step 2: Pour dibutyl phthalate into epoxy resin B glue and stir evenly to obtain modified epoxy resin B glue, then pour the conductive filler suspension into the modified epoxy resin B glue, mechanically stir at 450r / min for 15min to obtain a first mixed material, heat the first mixed material in an oven at 50°C to slowly evaporate the anhydrous ethanol;

[0066] Mixing the first mixed material after the anhydrous ethanol is volatilized with the polyolefin wax, and stirring until uniform;

[0067] Step 3: Add epoxy resin A glue to the mixture of the first mixed material and the polyolefin wax, and stir and mix thoroughly until uniform, to obtain a second mixed material;

[0068] Adding the organosilicon defoamer to the second mixed material and stirring until uniform;

[0069] Step 4: Move the mixture of the second mixed material and the silicone defoamer to a vacuum drying oven, evacuate the mixture at room temperature for 10 to 30 minutes to remove the bubbles inside, and obtain the epoxy resin conductive paste.

[0070] The epoxy resin conductive slurry is poured into a rectangular stainless steel mold. After the conductive slurry completely fills the stainless steel mold, it is moved to an oven at 110°C for 40 minutes to solidify and form. After cooling to room temperature, the conductive filler epoxy resin is demoulded from the original stainless steel mold to obtain a cathode core mold. Figure 1 shown.

[0071] See also Figure 5 This core mold is used as the cathode in the electroforming process. The conductivity of the core mold in copper sulfate solution can reach 0.21S·m -1 .

[0072] Example 3

[0073] The epoxy resin conductive paste includes epoxy resin A glue, flaky silver-coated copper conductive powder, spherical silver-coated copper conductive powder, doped flake graphite, dioctyl terephthalate, epoxy resin B glue, polyamide wax, and silicone defoamer. Among them, the mass ratio of epoxy resin A glue, flaky silver-coated copper conductive powder, spherical silver-coated copper conductive powder, doped flake graphite, dioctyl terephthalate, epoxy resin B glue, polyamide wax, and silicone defoamer is 1:5:5:2.5:0.4:1:0.125:0.1.

[0074] The preparation method of the epoxy resin conductive paste is as follows, and the contents of the components in the preparation method: the masses of epoxy resin A glue, flaky silver-coated copper conductive powder, spherical silver-coated copper conductive powder, doped flake graphite, dioctyl terephthalate, epoxy resin B glue, polyamide wax, and silicone defoaming agent are 10g, 50g, 50g, 25g, 4g, 10g, 1.25g, and 1g, respectively.

[0075] Step 1: Disperse flake graphite, flaky conductive silver-coated copper powder, and granular conductive silver-coated copper powder in a beaker containing 60 g of anhydrous ethanol according to the above proportions, and mechanically stir at 350 r / min for 1 hour to obtain a conductive filler suspension;

[0076] Step 2: Pour dioctyl terephthalate into epoxy resin B glue and stir evenly to obtain modified epoxy resin B glue, then pour the conductive filler suspension into the modified epoxy resin B glue, mechanically stir at 450r / min for 15min to obtain a first mixture, heat the first mixture in an oven at 50°C to slowly evaporate the anhydrous ethanol;

[0077] Mixing the first mixed material after the anhydrous ethanol is volatilized with the polyamide wax, and stirring until uniform;

[0078] Step 3: Add epoxy resin A glue to the mixture of the first mixed material and the polyamide wax, and stir and mix thoroughly until uniform, to obtain a second mixed material;

[0079] Adding the organosilicon defoamer to the second mixed material and stirring until uniform;

[0080] Step 4: Move the mixture of the second mixed material and the silicone defoamer to a vacuum drying oven; evacuate the mixture at room temperature for 10 to 30 minutes to remove the bubbles inside, thereby obtaining the epoxy resin conductive paste.

[0081] The epoxy resin conductive paste is poured into a cubic polytetrafluoroethylene mold. After the conductive paste completely fills the polytetrafluoroethylene mold, it is moved to an oven and kept at 110°C for 40 minutes to solidify and form. After cooling to room temperature, the conductive filler epoxy resin is demoulded from the original polytetrafluoroethylene mold to obtain a cubic cathode core mold. Figure 1 shown.

[0082] See also Figure 5 This cathode core mold is used as the cathode in the electroforming process. After testing, the conductivity of the cathode core mold in copper sulfate solution can reach 0.25S·m -1 .

[0083] It has been verified that the epoxy resin-based conductive paste of the embodiment of the present disclosure can completely replicate the shape of the forming mold, and the conductive epoxy resin cathode core mold after curing has a certain rigidity and is not easy to deform. Using it as a micro-electroforming cathode core mold can effectively improve the forming accuracy of metal parts, and the cathode core mold can be reused after demolding. It shows that the epoxy resin conductive cathode core mold prepared by the method of the present invention has excellent rigidity, conductivity and durability. In addition, the preparation method provided by the present disclosure has the advantages of simple operation, rapidity, high efficiency, and large-scale preparation.

[0084] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. An epoxy resin conductive paste for preparing an electroforming cathode core mold, characterized in that: The epoxy resin conductive paste comprises: epoxy resin A glue, flaky silver-coated copper powder, granular silver-coated copper powder, flake graphite and curing agent; Among them, the mass ratio of the epoxy resin A glue, the flaky silver-coated copper powder, the granular silver-coated copper powder, the flake graphite and the curing agent is (1-1.5): (2-5): (2-5): (1-2.5): 1, the average particle size of the flaky silver-coated copper powder is 10 μm, the average particle size of the granular silver-coated copper powder is 4 μm-5 μm, and the average particle size of the flake graphite is 30 μm.

2. The epoxy resin conductive paste according to claim 1, characterized in that: The epoxy resin conductive paste also includes: a plasticizer, an anti-settling agent and a defoamer. The mass ratio of the plasticizer, the anti-settling agent, the defoamer and the epoxy resin A glue is 0.4: (0.05-0.125): (0.04-0.1):

1.

3. The epoxy resin conductive paste according to claim 2, characterized in that: The plasticizer is one or more of dioctyl terephthalate, dibutyl phthalate, and dioctyl phthalate; The anti-settling agent is one of polyolefin wax and polyamide wax; The defoamer is an organosilicon defoamer.

4. The epoxy resin conductive paste according to claim 1, characterized in that: The epoxy resin A glue is E-44; The curing agent is epoxy resin B glue.

5. A method for preparing an epoxy resin conductive paste for preparing an electroforming cathode core mold, for preparing the epoxy resin conductive paste as claimed in any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: Step 1: Evenly mix flaky silver-coated copper powder, granular silver-coated copper powder, flake graphite and anhydrous ethanol to obtain a conductive filler suspension, wherein the mass ratio of the flaky silver-coated copper powder, granular silver-coated copper powder, flake graphite and anhydrous ethanol is (2-5): (2-5): (1-2.5): (2.5-6); Step 2: Mixing the curing agent and the conductive filler suspension to obtain a first mixture, heating the first mixture to evaporate the anhydrous ethanol, and the mass ratio of the curing agent to the flake graphite is 1: (1-2.5); Step 3: adding epoxy resin A glue to the first mixture after evaporation of anhydrous ethanol, stirring and mixing thoroughly to obtain a second mixture, wherein the mass ratio of the epoxy resin A glue to the curing agent is in the range of (1-1.5):1; Step 4: removing bubbles from the second mixture to obtain the epoxy resin conductive paste.

6. The preparation method according to claim 5, characterized in that: Before mixing the curing agent and the conductive filler suspension to obtain the first mixed material, the preparation method further comprises: The plasticizer is added into the curing agent and stirred evenly to modify the curing agent, wherein the mass ratio of the plasticizer to the curing agent is 0.4:

1.

7. The preparation method according to claim 5, characterized in that: Before adding epoxy resin A glue to the first mixed material after the anhydrous ethanol is evaporated, the method further comprises: Add the anti-settling agent to the first mixture and stir evenly. The mass ratio of the anti-settling agent to the curing agent is (0.05-0.125):

1.

8. The preparation method according to claim 5, characterized in that: The step of removing bubbles from the second mixed material comprises: Adding a defoamer to the second mixed material and stirring evenly, the mass ratio of the defoamer to the curing agent is (0.04-0.1):1; The mixture of the second mixed material and the defoaming agent is vacuumed to remove air bubbles therein.

9. The preparation method according to claim 5, characterized in that: The preparation method further comprises: The epoxy resin conductive paste is poured into the forming mold and cured, and the electroforming cathode core mold is formed after demoulding.

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