A wave-absorbing carbon slurry film, a preparation method and application thereof

Abstract

This invention provides a microwave-absorbing carbon paste film, its preparation method, and its application. The microwave-absorbing carbon paste film is obtained by printing microwave-absorbing carbon paste onto a substrate, followed by curing and drying using a printing ink film curing and heating device. The microwave-absorbing carbon paste, by weight, comprises: 4-15 parts superconducting carbon black, 10-35 parts graphite, 5-15 parts hydroxyl and / or carboxyl resin, 15-35 parts multifunctional epoxy resin, 2.9-6.7 parts curing agent, 0.15-0.35 parts accelerator, 0.5-5 parts dispersant, and 10-40 parts solvent. The mass ratio of the hydroxyl and / or carboxyl resin to the multifunctional epoxy resin is 0.16-0.75, and the multifunctional epoxy resin contains at least three functional groups. This invention, based on the polar synergistic effect between the hydroxyl resin and the multifunctional epoxy resin, enhances the bonding force and adhesion of the carbon paste, and improves the bonding strength between the carbon paste and the substrate.

Description

Technical Field

[0001] This invention relates to the field of microwave absorbing materials technology, and in particular to a method for preparing a carbon paste film and a method for preparing it into a resistive film material. Background Technology

[0002] Based on electromagnetic loss mechanisms, microwave absorbing materials can be mainly classified into resistive film type, dielectric type, and magnetic dielectric type. Resistive film type microwave absorbing materials are increasingly widely used due to their greater structural design flexibility, more stable equivalent impedance, wide absorption bandwidth, and thin thickness.

[0003] Resistive films are one of the key materials in resistive film-type microwave absorbing materials. They are generally produced by screen printing carbon paste onto a substrate and then drying and curing. However, bonding resistive films prepared using conventional carbon paste with foam materials presents the following problems: first, the adhesion between the resistive film and the adhesive is weak, leading to unstable microwave absorption; second, the internal bonding force of the resistive film is poor, resulting in uneven microwave absorption performance; and third, the adhesion between the resistive film layer and the substrate is poor, resulting in low tensile strength and peel strength. These issues contribute to the overall low mechanical strength of the microwave absorbing material, limiting its application in microwave absorbing applications. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the background art above, and to provide a microwave absorbing carbon paste film, its preparation method and application. The carbon paste film is based on the polar synergistic effect between hydroxyl resin and / or carboxyl resin and multifunctional epoxy resin, which strengthens the internal bonding force of the carbon paste film layer and the adhesion to the substrate, and improves the bonding strength between the carbon paste film layer and the substrate.

[0005] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0006] A microwave absorbing carbon paste film, wherein the microwave absorbing carbon paste film is obtained by printing microwave absorbing carbon paste onto a substrate, and then curing, heating and drying it using a printing ink film curing and heating device.

[0007] The microwave-absorbing carbon paste, by mass fraction, comprises:

[0008] 4-15 parts superconducting carbon black, 10-35 parts graphite, 5-15 parts hydroxyl resin and / or carboxyl resin, 15-35 parts multifunctional epoxy resin, 2.9-6.7 parts curing agent, 0.15-0.35 parts accelerator, 0.5-5 parts dispersant, 10-40 parts solvent, wherein the mass ratio of the hydroxyl resin and / or carboxyl resin to the multifunctional epoxy resin is 0.16-0.75, and the multifunctional epoxy resin has at least 3 functional groups.

[0009] Preferably, the multifunctional epoxy resin is one of trifunctional S-186 and tetrafunctional S-720 epoxy resins; the hydroxyl resin is a long-chain flexible resin, and the hydroxyl resin is one of hydroxyl chloride resin and PVB resin.

[0010] Preferably, the specific surface area of ​​the superconducting carbon black is greater than 200 m². 2 / g, wherein the graphite particle size is 1000-2500 mesh, the curing agent is a latent dicyandiamide curing agent, the accelerator is DMP30, the dispersant is one or more of BYK-163, BYK-190, AKN-2320, and AKN-291, and the solvent is one or more of cyclohexanone, isoflurone, and DBE.

[0011] This invention enhances the bonding and adhesion of carbon paste by leveraging the polar synergistic effect between hydroxyl and / or carboxyl resins and multifunctional epoxy resins, thereby improving the bonding strength between the carbon paste and the substrate. By adjusting the mass ratio of the two components, carbon paste suitable for different types of substrates can be prepared.

[0012] Based on the overall inventive concept, the present invention also provides a method for preparing a microwave-absorbing carbon slurry film, comprising the following steps:

[0013] (1) Preparation method of microwave absorbing carbon paste: After dissolving the thermoplastic resin, add other additives and grind and disperse to obtain the microwave absorbing carbon paste;

[0014] (2) Printing of microwave absorbing carbon paste film: The microwave absorbing carbon paste prepared in step (1) is printed on the substrate to obtain a printed microwave absorbing carbon paste film.

[0015] (3) Curing and heating of printed microwave absorbing carbon paste film: After curing and heating the printed microwave absorbing carbon paste film obtained in step (2) through a printing ink film curing and heating device, the microwave absorbing carbon paste film is obtained.

[0016] Preferably, step (1) is specifically operated as follows: hydroxyl resin is added to solvent and stirred at 65-75℃ until the resin is completely dissolved; after adding superconducting carbon black, graphite, dispersant, curing agent and multifunctional epoxy resin, they are added together to planetary ball mill jar and ball milled and dispersed evenly; then an accelerator is added and the mixture is ground and dispersed to a fineness of ≤8μm by a three-roll mill to obtain microwave absorbing carbon paste.

[0017] Preferably, the substrate in step (2) is one or a combination of FR4, PI film, and PET film.

[0018] Preferably, the printing ink film curing heating device in step (3) includes a heating device body and a conveying component, a preheating component, a heating component, and a cooling component located on the heating device body; the conveying component consists of a conveyor belt, a conveying transmission structure, and a drive unit, and the conveyor belt is provided with a conveying correction component and a fastening structure.

[0019] Preferably, the preheating component of the printing ink film curing heating device consists of a first heating structure and an inner insulation layer. The preheating component is disposed close to the inner side of the conveyor belt or on the lower side of the conveying component. The heating component is located on the upper side of the conveying component and consists of a second heating structure, an inner insulation layer, and an outer insulation layer. A temperature control system is also provided inside the heating device body. The temperature control system is used to control the temperature and heating rate inside the preheating component and the heating component. A locking device is provided on the conveying component, and the locking device is connected to the drive unit and the conveying correction component. The conveying correction component consists of a correction component cylinder, a correction roller, and a sensor. The fastening structure is located on both sides of the conveyor belt and consists of a slot, a cylinder, and a clamping element.

[0020] Preferably, when the printing ink film curing heating device is used to heat and cure the printed microwave absorbing carbon paste film, the temperature range of the preheating component is 90℃-100℃; and the temperature range of the heating component is 150℃-220℃.

[0021] Based on the overall inventive concept, the present invention also provides an application of a microwave absorbing carbon paste film, wherein the microwave absorbing material is prepared by bonding the microwave absorbing carbon paste film with a foam material using an epoxy adhesive; the foam material is one or more of polyurethane foam and polymethacrylamide foam.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. The microwave absorbing carbon paste film of the present invention uses a resin system of hydroxyl resin and / or carboxyl resin and a multifunctional epoxy resin as the adhesive phase. Based on the polar synergistic effect of the two, the bonding force and adhesion of the carbon paste are enhanced, and the bonding strength between the carbon paste and the substrate is improved. According to experimental tests, the carbon paste for microwave absorbing materials of the present invention has a tensile strength ≥1 MPa.

[0024] 2. The microwave absorbing carbon paste provided by this invention utilizes thermoplastic hydroxyl resin to provide the flexibility of the carbon paste curing film, enabling it to be used for printing on flexible ultrathin substrates and exhibiting good bending resistance. Thermosetting epoxy resin provides the rigidity of the cured film and strong internal bonding force. The polar groups in the hydroxyl resin and epoxy resin provide strong adhesion to the substrate and strong bonding strength between the film and the adhesive. By adjusting the ratio of thermoplastic resin and thermosetting resin, carbon paste suitable for different types of substrates can be prepared, resulting in resistive film materials for different types of substrates, satisfying the resistive film materials for different flexible or brittle substrates. For example, reducing the content of multifunctional epoxy resin can prepare carbon paste suitable for ultrathin flexible PET or PI films, while increasing the content of multifunctional epoxy resin can prepare carbon paste suitable for rigid FR4 films.

[0025] 3. The microwave absorbing carbon paste provided by this invention can achieve good adhesion strength between the printed microwave absorbing carbon paste film material and the foam material. The microwave absorbing material prepared using this microwave absorbing carbon paste film material can achieve a tensile strength of 1 MPa, which meets the requirements for use. Attached Figure Description

[0026] Figure 1 A schematic diagram of an ink film curing heating device;

[0027] Figure 2 A schematic diagram of the conveyor belt in an ink film curing heating device;

[0028] Figure 3 A schematic diagram of the structure of the correction component for the ink film curing heating device.

[0029] Figure label:

[0030] 1. Second heating structure; 2. No. 1 blower; 3. Heating tube; 4. Air inlet; 5. Outer insulation layer; 6. Inner insulation layer; 7. Air outlet; 8. Conveying structure A; 9. No. 2 blower; 10. Base support; 11. First heating structure; 12. Air inlet; 13. Blower; 14. Heating tube; 15. Temperature adjustment unit; 16. Speed ​​adjustment unit; 17. Display screen; 18. Drive unit; 19. Conveying structure B; 20. Conveyor belt; 21. Correction component cylinder; 22. Correction roller; 23. Sensor; 24. Lower support roller; 25. Conveying correction component A; 26. Conveying correction component B; 27. Locking device; 28. Slot; 29. ​​Clamping element; 30. Cylinder. Detailed Implementation

[0031] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0032] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0033] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0034] Example 1:

[0035] A microwave-absorbing carbon slurry film, its preparation method and application:

[0036] Weigh the following ingredients: 7g superconducting carbon black; 20g graphite; 5g hydroxychlorovinyl acetate resin; 30g S182 epoxy resin; 5.7g dicyandiamide; 0.3g DMP30; 0.5g BYK-163; 21.5g DBE solvent; 10g isoflurane.

[0037] Pulping steps: (1) First, accurately weigh 5g of hydroxychloroacetic acid resin, 21.5g of DBE solvent and 10g of isoflurane solvent, and stir at 70°C until the resin is completely dissolved.

[0038] (2) Add 7g of superconducting carbon black, 20g of graphite, 30g of S-186 epoxy resin, 25.7g of dicyandiamide, 0.5g of BYK-163 and dissolved hydroxychloroacetic acid resin into a planetary ball mill jar and disperse them evenly by ball milling.

[0039] (3) Finally, add 0.3g of accelerator DMP30 and grind and disperse it to a fineness of less than 8 micrometers using a three-roll mill to obtain carbon paste.

[0040] The carbon paste prepared above was printed onto 0.05mm FR4 and PI films respectively, and dried and cured to obtain microwave absorbing carbon paste film material. The microwave absorbing carbon paste film material was bonded to foam material with epoxy adhesive and then hot-pressed and cured to obtain microwave absorbing material.

[0041] Samples were prepared according to GB / T1452-2018 standard, and the tensile strength of the prepared microwave absorbing materials is shown in Table 1 below. In this example, the mass ratio of hydroxyl resin to multifunctional epoxy resin was 0.16. The high proportion of multifunctional epoxy resin makes the prepared carbon paste more suitable for combining with the brittle FR4 film, thereby improving the mechanical strength of the brittle microwave absorbing material. Experimental test data show that the carbon paste prepared using the method in Example 1, when used to prepare brittle microwave absorbing materials, exhibits tensile strengths greater than 1 MPa.

[0042] Table 1: Tensile strength of the microwave absorbing material prepared in Example 1

[0043]

[0044] Example 2:

[0045] A microwave-absorbing carbon slurry film, its preparation method and application:

[0046] Weigh the following ingredients: 7g superconducting carbon black; 20g graphite; 10g PVB resin; 25g S-186 epoxy resin; 4.8g dicyandiamide; 0.25g DMP30; 0.5g BYK-163; 20g isoflurone; 12.45g DBE.

[0047] Pulping steps: (1) First, accurately weigh 10g of PVB resin, 20g of isoflurone and 12.45g of DBE solvent, and stir at 70°C until the resin is completely dissolved.

[0048] (2) Add 7g of superconducting carbon black, 20g of graphite, 25g of S-186 epoxy resin, 4.8g of dicyandiamide, 0.5g of BYK-163 and dissolved PVB resin into a planetary ball mill jar and disperse them evenly by ball milling.

[0049] (3) Finally, add 0.25g of accelerator DMP30 and grind and disperse it to a fineness of less than 8 micrometers using a three-roll mill to obtain carbon paste.

[0050] The carbon paste prepared above was printed onto 0.05mm FR4 and PI films respectively, and dried and cured to obtain microwave absorbing carbon paste film material. The microwave absorbing carbon paste film material was bonded to foam material with epoxy adhesive and then hot-pressed and cured to obtain microwave absorbing material.

[0051] Samples were prepared according to GBT1452-2018 standard, and the tensile strength of the prepared microwave absorbing materials is shown in Table 2 below. In this embodiment, the mass ratio of hydroxyl resin to multifunctional epoxy resin is 0.4. The ratio of hydroxyl resin to multifunctional epoxy resin is appropriate, and the prepared carbon paste has strong applicability. It can be combined with both brittle FR4 films and flexible PI films, and has strong adaptability to substrates. Through experimental test data, the carbon paste prepared by the method of Example 2 is used to prepare microwave absorbing carbon paste film materials for brittle substrates. The tensile strength of the prepared microwave absorbing carbon paste film materials for flexible substrates is greater than 1 MPa. See Table 2 for details.

[0052] Table 2: Tensile strength of the microwave absorbing material prepared in Example 2

[0053]

[0054] Example 3:

[0055] A microwave-absorbing carbon slurry film, its preparation method and application:

[0056] Weigh the following ingredients: 10g superconducting carbon black; 10g graphite; 15g hydroxychlorovinyl acetate resin; 20g S-720 epoxy resin; 3.7g dicyandiamide; 0.20g DMP30; 0.8g BYK-190; 10g DBE solvent; 20.82g isoflurane; 10g cyclohexanone.

[0057] Pulping steps: (1) First, accurately weigh 15g of hydroxychloroacetic acid resin, 10g of DBE solvent, 20.82% isoflurane and 10g of cyclohexanone solvent, and stir at 70°C until the resin is completely dissolved.

[0058] (2) Add 10g of superconducting carbon black, 10g of graphite, 20g of S-720 epoxy resin, 3.7g of dicyandiamide, 0.8g of BYK-190 and dissolved hydroxychloroacetic acid resin into a planetary ball mill jar and disperse them evenly by ball milling.

[0059] (3) Finally, add 0.20g of accelerator DMP30 and grind and disperse it to a fineness of less than 8 micrometers using a three-roll mill to obtain carbon paste.

[0060] The carbon paste prepared above is printed onto 0.05mm FR4 and PI films, dried and cured to obtain microwave absorbing carbon paste film material. The microwave absorbing carbon paste film material is then bonded to foam material with epoxy adhesive, hot-pressed and cured to obtain microwave absorbing material.

[0061] Samples were prepared according to GBT1452-2018 standard, and the tensile strength of the prepared microwave absorbing materials is shown in Table 3 below. In this example, the mass ratio of hydroxyl resin to multifunctional epoxy resin is 0.75, which is suitable. The carbon paste prepared has good bonding performance with both the brittle FR4 film and the flexible PI film. The carbon paste prepared by the method in Example 3 was used to prepare microwave absorbing carbon paste film materials with brittle substrates, and the tensile strength of the microwave absorbing materials was greater than 1 MPa. The tensile strength of the microwave absorbing carbon paste film materials prepared with flexible substrates was also close to 1 MPa.

[0062] Table 3: Tensile strength of the microwave absorbing material prepared in Example 3

[0063]

[0064] Comparative Example 1:

[0065] A microwave-absorbing carbon paste film, its preparation method and application: (single thermoplastic hydroxyl resin system)

[0066] Weigh the following ingredients: 7g superconducting carbon black; 20g graphite; 35g hydroxychloroacetic acid resin; 0.5g AKN-2320; 10g cyclohexanone; 5g DBE solvent; 22.5g isoflurane.

[0067] Pulping steps: (1) First, accurately weigh 35g of hydroxychloroacetic acid resin, 10g of cyclohexanone, 5g of DBE solvent and 22.5g of isoflurane, and stir at 70°C until the resin is completely dissolved.

[0068] (2) Add 7g of superconducting carbon black, 20g of graphite, 0.5g of AKN-2320 and dissolved hydroxychloroacetic acid resin to a planetary ball mill jar and disperse them evenly by ball milling.

[0069] (3) Finally, the carbon paste is ground and dispersed to a fineness of less than 8 micrometers by a three-roll mill.

[0070] The carbon paste prepared above is printed onto 0.05mm FR4 and PI films, dried and cured to obtain microwave absorbing carbon paste film material. The microwave absorbing carbon paste film material is then bonded to foam material with epoxy adhesive, hot-pressed and cured to obtain microwave absorbing material.

[0071] Samples were prepared according to GBT1452-2018 standard, and the tensile strength of the prepared microwave absorbing materials is shown in Table 4 below. Through analysis of the test data, it was found that the microwave absorbing carbon paste prepared by using a single thermoplastic hydroxyl resin system and brittle FR4 and flexible PI film as substrates has low film strength. When the prepared microwave absorbing materials are stretched, the failure occurs inside the film layer, and the tensile strength is below 1 MPa.

[0072] Table 4: Tensile strength of the absorbing material prepared in Comparative Example 1

[0073]

[0074] Comparative Example 2:

[0075] A microwave-absorbing carbon paste film, its preparation method and application: (single thermosetting epoxy resin system)

[0076] Weigh the following ingredients: 7g superconducting carbon black; 20g graphite; 35g S-186 resin; 6.7g dicyandiamide; 0.35g DMP30; 0.5g AKN-291; 30.45g DBE solvent.

[0077] Pulping steps: (1) Add 7g of superconducting carbon black, 20g of graphite, 35g of S-186 resin, 6.7g of dicyandiamide and 0.5g of AKN-291 to the planetary ball mill jar and disperse them evenly by ball milling.

[0078] (2) Finally, add 0.35g of accelerator DMP30 and grind and disperse it to a fineness of less than 8 micrometers using a three-roll mill to obtain carbon paste.

[0079] The carbon paste prepared above was printed onto 0.05mm FR4 and PI films respectively, and dried and cured to obtain microwave absorbing carbon paste film material. The microwave absorbing carbon paste film material was bonded to the foam material with epoxy adhesive and then cured by hot pressing.

[0080] Samples were prepared according to GBT1452-2018 standard. The tensile strength of the prepared microwave absorbing materials is shown in Table 5 below. Through analysis of the test data, the microwave absorbing carbon paste film material prepared by using a single thermosetting epoxy resin system and brittle FR4 and flexible PI film as substrates is very brittle and has an orange peel-like surface. When the prepared microwave absorbing material is stretched, it is basically destroyed at the interface between the microwave absorbing carbon paste film layer and the substrate. The tensile strength is below 1 MPa.

[0081] Table 5: Tensile strength of the microwave absorbing material prepared in Comparative Example 2

[0082]

[0083] Example 4:

[0084] A heating device for curing printing ink films:

[0085] like Figure 1 , Figure 2 , Figure 3 As shown, this embodiment provides a printing ink film curing heating device, including a heating device body and a conveying component, a preheating component, a heating component, and a cooling component located on the heating device body. The conveying component consists of a conveyor belt 20, a conveying transmission structure A 8, and a driving unit 18. The conveying component is driven by the driving unit 18 to rotate the conveying transmission structure A 8, thereby driving the conveyor belt 20 to transport the ink film. The conveyor belt 20 is provided with an ink film conveying correction component A 25 and an ink film fastening structure. On the other side, there is a corresponding conveying transmission structure B 19 and a conveying correction component B 26. The preheating component consists of a first heating structure 11 and an inner insulation layer 6, and is located below the conveying component. The heating component is located above the conveying component and consists of a second heating structure 1, an inner insulation layer 6, and an outer insulation layer 5. The heating device body is also provided with a temperature control system 15, a speed regulation unit 16, and a display screen 17. The temperature control system 15 is used to control the temperature and heating rate of the preheating component and the heating component. Blower No. 2 (9) and air outlet (7) are located in the cooling section.

[0086] The preheating component is located below the conveying component. It heats the bottom layer of the printed carbon paste film first, allowing the solvent in the bottom layer to evaporate first, followed by the solvent in the upper layer, ensuring complete solvent evaporation. When entering the heating component, both the upper and lower surfaces of the carbon paste film on the conveyor belt are heated, resulting in rapid heating and stable temperature control, ensuring more thorough heating and drying. The conveyor belt alignment component 25, combined with the fastening structure, enables stable conveying of the carbon paste film, preventing curling and misalignment during the preheating and conveying process.

[0087] The conveying assembly is equipped with a locking device 27 for adjusting the tension of the conveyor belt; the conveying assembly also includes several lower idlers 24, which are evenly spaced on the heating device body to support the conveyor belt 20.

[0088] The conveyor belt correction assembly consists of a correction assembly cylinder 21, a correction roller 22, and a sensor 23. The conveyor belt correction assembly is used to protect the conveyor belt. When the sensor 23 detects that the conveyor belt is off-track, the correction assembly cylinder 21 drives the correction roller 22 to automatically correct the conveyor belt 20. When the conveyor belt is seriously off-track, the connected locking device can control the conveyor to stop rotating.

[0089] The fastening structure is located on both sides of the conveyor belt 20 and is used to fix the carbon paste film placed on the conveyor belt. The carbon paste film fastening structure consists of a slot 28, a cylinder 30 and a clamping element 29. The slot 28 is located on both sides of the conveyor belt in the width direction and is parallel to the conveyor belt transport direction. The cylinder controls the clamping elements to be arranged at intervals in the slot to achieve the clamping and fixing of the carbon paste film.

[0090] The second heating structure 1 consists of a blower 2, a heating tube 3, and an air inlet 4. The first heating structure 11 consists of a blower 13, a heating tube 14, and an air inlet 12. Both the preheating and heating components use forced-air heating. The blower can evenly heat the conveyor belt with the emitted heat, while simultaneously creating convection currents between the air inside and outside the furnace to stabilize the temperature.

[0091] The inner insulation layer 6 is made of rock wool containing aluminum silicate.

[0092] The temperature control system includes a PID temperature controller and an SSR component. The PID temperature controller, combined with the phase output control of the SSR component, results in more stable temperature control.

[0093] The temperature control system controls the preheating component to a heating temperature range of 90°C and the heating component to a heating temperature range of 160°C.

Claims

1. A method for preparing a microwave-absorbing carbon slurry film, characterized in that, The microwave absorbing carbon paste is composed of the following components by mass: 4-15 parts superconducting carbon black, 10-35 parts graphite, 5-15 parts hydroxyl and / or carboxyl resin, 15-35 parts multifunctional epoxy resin, 2.9-6.7 parts curing agent, 0.15-0.35 parts accelerator, 0.5-5 parts dispersant, 10-40 parts solvent, wherein the mass ratio of the hydroxyl and / or carboxyl resin to the multifunctional epoxy resin is 0.16-0.75, and the multifunctional epoxy resin has at least 3 functional groups; The preparation method includes the following steps: (1) Preparation method of microwave absorbing carbon paste: After dissolving the thermoplastic resin, add other additives and grind and disperse to obtain the microwave absorbing carbon paste; (2) Printing of microwave absorbing carbon paste film: The microwave absorbing carbon paste prepared in step (1) is printed on the substrate to obtain a printed microwave absorbing carbon paste film. (3) Curing and heating of printed microwave absorbing carbon paste film: After curing and heating the printed microwave absorbing carbon paste film obtained in step (2) through a printing ink film curing and heating device, the microwave absorbing carbon paste film is obtained. The printing ink film curing heating device includes a heating device body and a conveying assembly, a preheating assembly, a heating assembly, and a cooling assembly located on the heating device body. The conveying assembly consists of a conveyor belt, a conveying transmission structure, and a drive unit. The conveyor belt is equipped with a conveying correction assembly and a fastening structure. The preheating assembly consists of a first heating structure and an inner insulation layer. The preheating assembly is located close to the inner side of the conveyor belt or below the conveying assembly. The heating assembly is located above the conveying assembly and consists of a second heating structure, an inner insulation layer, and an outer insulation layer. A temperature control system is also provided inside the heating device body. The temperature control system is used to control the temperature and heating rate inside the preheating assembly and the heating assembly. The conveying assembly is equipped with a locking device, which is connected to the drive unit and the conveying correction assembly. The conveying correction assembly consists of a correction assembly cylinder, a correction roller, and a sensor. The fastening structure is located on both sides of the conveyor belt and consists of a slot, a cylinder, and a clamping element.

2. The preparation method according to claim 1, characterized in that, The multifunctional epoxy resin is one of trifunctional S-186 and tetrafunctional S-720 epoxy resins; the hydroxyl resin is a long-chain flexible resin, and the hydroxyl resin is one of hydroxyl chloride resin and PVB resin.

3. The preparation method according to claim 1, characterized in that, The specific surface area of ​​the superconducting carbon black is greater than 200 m². 2 / g, wherein the graphite particle size is 1000-2500 mesh, the curing agent is a latent dicyandiamide curing agent, the accelerator is DMP30, the dispersant is one or more of BYK-163, BYK-190, AKN-2320, and AKN-291, and the solvent is one or more of cyclohexanone, isoflurone, and DBE.

4. The preparation method according to claim 1, characterized in that, The specific operation of step (1) is as follows: add hydroxyl resin to solvent and stir at 65-75℃ until the resin is completely dissolved; add superconducting carbon black, graphite, dispersant, curing agent and multifunctional epoxy resin, and then add them together to planetary ball mill jar and ball mill to disperse them evenly; then add accelerator and grind and disperse them to fineness ≤8μm by three-roll mill to obtain microwave absorbing carbon paste.

5. The preparation method according to claim 1, characterized in that, The substrate mentioned in step (2) is one or more of FR4, PI film, and PET film.

6. The preparation method according to claim 1, characterized in that, When the printing ink film curing heating device is used to cure and heat the printed microwave absorbing carbon paste film, the temperature range of the preheating component is 90℃-100℃; the temperature range of the heating component is 150℃-220℃.

7. An application of a microwave-absorbing carbon slurry film obtained by the preparation method according to any one of claims 1-6, characterized in that, The microwave absorbing material is prepared by bonding the microwave absorbing carbon paste film and the foam material with epoxy adhesive; the foam material is one or more of polyurethane foam and polymethacrylamide foam.

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