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CN-122010568-A - Preparation method of high-heat-conductivity graphene heat-conducting film

CN122010568ACN 122010568 ACN122010568 ACN 122010568ACN-122010568-A

Abstract

The invention belongs to the field of heat conduction materials, and particularly relates to a preparation method of a high-heat-conduction graphene heat conduction film. Through the combination of a plurality of graphene materials (such as mechanically peeled graphene, reduced graphene oxide and the like), a carbonaceous material is adopted as a dispersoid, the content of bound water and hydrogen bonds is reduced, the production efficiency is improved, and meanwhile, the mutual lap joint of the graphene materials is realized by using a three-roller machine for dispersion, so that the internal arrangement of the film materials is more uniform and compact, and the heat conductivity of the heat conducting film is remarkably improved.

Inventors

  • YANG YAMIN
  • ZHANG XIAOYU

Assignees

  • 北京微焓科技有限公司

Dates

Publication Date
20260512
Application Date
20260210

Claims (10)

  1. 1. The preparation method of the high-heat-conductivity graphene heat-conducting film is characterized by comprising the following steps of: (1) Respectively weighing a heat conducting material, dispersoids and a solvent according to the mass ratio of 1:0.01-0.5:1-3, uniformly stirring in a dispersing machine, and homogenizing by a homogenizer to obtain slurry; (2) Grinding the homogenized slurry for 2-4 times by using a three-roller grinder, then carrying out vacuum defoaming by using a defoaming machine, coating the defoamed slurry into a film with the thickness of 1000-5000 mu m, drying and then rolling; (3) The coiled material is put into a baking oven and is treated at the low temperature of 50-180 ℃ to crosslink dispersoids with hydroxyl groups and/or carboxyl groups on the surface of the heat conducting material; (4) Placing the coiled material subjected to low-temperature treatment into a carbonization furnace, carbonizing at 800-1200 ℃, placing into a graphitization furnace after the carbonization treatment is finished, graphitizing at 2500-3000 ℃, naturally cooling, taking out a film material, rolling by using a pair of rollers, and packaging and outputting a finished product of a cut piece; The heat conducting material is selected from at least 2 of mechanically exfoliated graphene, reduced graphene oxide, CVD grown graphene, graphene oxide and carbon nanotubes, the dispersoid is selected from one or more of sodium alginate, acrylic resin, coal tar, asphalt base, dianhydride, diamine and acrylonitrile, and the solvent is selected from one or more of deionized water, ethanol, methanol, NMP and DMF.
  2. 2. The method of claim 1, wherein the thermally conductive material is selected from at least 2 of mechanically exfoliated graphene, reduced graphene oxide, CVD grown graphene, graphene oxide, and carbon nanotubes, each of which is 10% -80% of the total thermally conductive material mass.
  3. 3. The preparation method of claim 1, wherein the solvent comprises deionized water as a main component, and the deionized water accounts for 60% -100% of the total mass of the solvent.
  4. 4. The method according to claim 1, wherein the stirring speed of the disperser is 1000-5000 rpm and the stirring time is 0.5-2 hours.
  5. 5. The method according to claim 1, wherein the homogenizer homogenizes 2 to 3 times under 50 to 110 mpa.
  6. 6. The method according to claim 1, wherein the three-roll grinder is used for grinding, the rotation speed ratio of the front roll to the rear roll is 1:3:9, and the roll gap is adjusted to 1-30 μm.
  7. 7. The method according to claim 1, wherein the speed of the defoaming machine is 2000-4000 rpm, the vacuum degree is 50-150 mpa, and the defoaming time is 2-5 min.
  8. 8. The method of claim 1, wherein the film has a density of 2.0 to 2.2g/cm 3 after rolling.
  9. 9. A high thermal conductivity graphene thermal conductive film prepared by the preparation method of any one of claims 1-8.
  10. 10. A thermally conductive gasket prepared using the high thermal conductivity graphene thermally conductive film of claim 9.

Description

Preparation method of high-heat-conductivity graphene heat-conducting film Technical Field The invention belongs to the field of heat conduction materials, and particularly relates to a preparation method of a high-heat-conduction graphene heat conduction film. Background Graphene is a two-dimensional nanomaterial formed by monoatomic layers, has extremely high thermal conductivity, excellent mechanical property and good electrical property, the theoretical thermal conductivity of single-layer graphene can reach 5300W/m.k, is higher than that of single-wall carbon nanotubes (3500W/m.k) and multi-wall carbon nanotubes (3000W/m.k), is the currently known material with the highest thermal conductivity, is one of the materials with the highest known strength, has good toughness, can be bent, has the theoretical Young modulus of graphene reaching 1.0TPa, and has the inherent tensile strength of 130GPa. The graphene heat conduction film is prepared by stacking graphene single-layer sheets layer by layer. The existing main preparation process flow is that Graphene Oxide (GO) is prepared by stirring, dispersing, homogenizing, coating to form a film, cutting and carbonizing, graphitizing and calendaring. However, the prior art route suffers from a number of drawbacks: ① The early-stage raw material is graphene oxide, so that the graphene oxide has a plurality of defects, the reduction repair in the graphitization stage can only partially repair, the highest thermal conductivity can only achieve 2000W/m.k (70-micrometer thickness) at present, but the graphitization temperature needs to reach 3150 ℃, and the cost is more than 2 times of the graphitization temperature 2900 ℃, so that the graphene oxide is not beneficial to batch production; ② Functional groups such as-OH, -COOH and the like contained in the graphene oxide are easy to form hydrogen bonds with H 2 O, so that the volatilization of bound water is slow, and the coating and drying rate is limited; ③ Because the viscosity is too high, the solid content of the slurry is generally less than 8%, the coating film thickness cannot be thicker, the thick film needs lamination and lamination, the interlayer thermal resistance is increased, and the layering is easy; ④ The GO raw material functional groups are removed and a large amount of gas (such as CO and CO 2) is released in the high-temperature process, the gas accumulation causes expansion of a film, the structural defects are increased, and the heat conductivity is seriously reduced; ⑤ The expansion of the film material in the carbonization and graphitization treatment process is 5-10 times of that of the original film material, the production process can only cut pieces, and the film material cannot be rolled to be rolled, so that the production efficiency is low; ⑥ In order to obtain a product with higher heat conductivity, graphitization repair generally needs higher temperature, 3150 ℃ needs to be reached, the temperature is close to the upper limit temperature of 3200 ℃ of a graphitization furnace, the loss of equipment is huge, the energy consumption is huge, and the cost is doubled; ⑦ The yield is less than 90%, and a large amount of dust is generated in the graphitization process and adheres to the surface of the film, so that a large amount of defective products are caused mainly because of too many impurities in the raw material GO. With the increase of heating power of future electronic products, products with higher thermal conductivity and low cost are required, and how to further improve the thermal conductivity of the graphene thermal conductive film becomes a problem to be solved. Disclosure of Invention In order to solve the technical problems, the invention provides a preparation method of a high-heat-conductivity graphene heat-conducting film, which adopts a carbonaceous material as a dispersoid through the combination of a plurality of graphene materials, reduces the content of bound water and hydrogen bonds, improves the production efficiency, and simultaneously realizes the mutual lap joint of the graphene materials by using a three-roller machine for dispersion, so that the internal arrangement of the film materials is more uniform and compact, and the heat conductivity of the heat-conducting film is obviously improved. The invention adopts the following technical scheme: a preparation method of a high-heat-conductivity graphene heat-conducting film comprises the following steps: (1) Respectively weighing a heat conducting material, dispersoids and a solvent according to the mass ratio of 1:0.01-0.5:1-3, uniformly stirring in a dispersing machine, and homogenizing by a homogenizer to obtain slurry; (2) Grinding the homogenized slurry for 2-4 times by using a three-roller grinder, then carrying out vacuum defoaming by using a defoaming machine, coating the defoamed slurry into a film with the thickness of 1000-5000 mu m, drying and then rolling; (3) The coiled material is put into a baking