阅读说明：本技术 一种双面粘合的高导热合成石墨片及其制备方法 (Double-sided adhesive high-thermal-conductivity synthetic graphite flake and preparation method thereof ) 是由 薛仁宾 李小龙 于 2021-06-25 设计创作，主要内容包括：本发明涉及石墨片技术领域,具体为一种双面粘合的高导热合成石墨片及其制备方法,包括包括以下重量份原料：石墨片60-70份、改性碳纤维15-25份、导热胶3-5份；本发明通过加入碳纤维和铜粉,采用真空蒸镀的方法将铜镀在碳纤维的表面,使得铜镀层的厚度为5-7μm,形成改性碳纤维,提高了碳纤维本身的强度,同时,改性碳纤维与石墨片混合、压制成高导热性石墨片,改性碳纤维上的铜粉也被穿插在石墨片之间,铜粉的散热性较好,大幅度提高了高导热性石墨片沿其厚度方向的导热性,也提高了高导热性石墨片的整体导热性。(The invention relates to the technical field of graphite flakes, in particular to a double-sided bonded high-thermal-conductivity synthetic graphite flake and a preparation method thereof, wherein the graphite flake comprises the following raw materials in parts by weight: 60-70 parts of graphite flakes, 15-25 parts of modified carbon fibers and 3-5 parts of heat conducting glue; according to the invention, the carbon fiber and the copper powder are added, and the copper is plated on the surface of the carbon fiber by adopting a vacuum evaporation method, so that the thickness of a copper plating layer is 5-7 μm, the modified carbon fiber is formed, the strength of the carbon fiber is improved, meanwhile, the modified carbon fiber and the graphite flake are mixed and pressed into the high-thermal-conductivity graphite flake, the copper powder on the modified carbon fiber is also inserted among the graphite flakes, the heat dissipation performance of the copper powder is better, the thermal conductivity of the high-thermal-conductivity graphite flake along the thickness direction of the high-thermal-conductivity graphite flake is greatly improved, and the overall thermal conductivity of the high-thermal-conductivity graphite flake is also improved.)

1. A double-sided bonded high-heat-conductivity synthetic graphite sheet is characterized by comprising the following raw materials in parts by weight: 60-70 parts of graphite flakes, 15-25 parts of modified carbon fibers and 3-5 parts of heat conducting glue.

2. A double-sided bonded high thermal conductivity synthetic graphite sheet according to claim 1, wherein said graphite sheet is prepared by the following method:

s1: crushing the carbon black, and removing iron impurities from the crushed carbon black through a magnetic separator;

s2: and (4) putting the carbon black subjected to impurity removal into a graphitization furnace for graphitization treatment to obtain graphite flakes.

3. The double-sided bonded high thermal conductivity synthetic graphite sheet according to claim 2, wherein the graphitization treatment temperature is 2200-.

4. A double-sided bonded high thermal conductivity synthetic graphite sheet according to claim 2, wherein the crushed carbon black has a particle size of 0.1 to 0.3 mm.

5. The double-sided bonded high thermal conductivity synthetic graphite sheet according to claim 1, wherein the modified carbon fiber is prepared by the following method:

1) ultrasonically cleaning carbon fibers by using 75 wt% ethanol solution for 15-20min, washing the carbon fibers by using deionized water for 2-3 times, and then drying the carbon fibers;

2) and (3) putting the dried carbon fiber into vacuum evaporation equipment, putting a copper source into an evaporation chamber, and plating copper on the surface of the carbon fiber to form a copper coating to obtain the modified carbon fiber.

6. The double-sided bonded high thermal conductive synthetic graphite sheet according to claim 5, wherein the heating temperature of the copper source is 2590 ℃ and 2600 ℃, and the thickness of the copper plating layer is 5-7 μm.

7. The method for preparing a double-sided bonded high thermal conductivity synthetic graphite sheet according to any one of claims 1 to 6, comprising the steps of:

(1) mixing graphite flakes, modified carbon fibers and heat-conducting glue in proportion, placing the mixture into a mold, pressing and molding the mixture, taking the mixture out, placing the mixture into a thermostat for curing, then preserving heat for 1-2 hours, and cooling to obtain a high-heat-conductivity synthetic graphite flake;

(2) coating a layer of double-sided adhesive tape on both sides of the high-thermal-conductivity synthetic graphite sheet, and adhering a layer of release paper on the double-sided adhesive tape to obtain the double-sided adhesive high-thermal-conductivity synthetic graphite sheet.

8. The method of claim 7, wherein in the step (1), the thickness of the highly thermally conductive synthetic graphite sheet is 0.02 to 0.05 mm.

9. The method for preparing double-sided bonded high thermal conductivity synthetic graphite sheet according to claim 7, wherein in the step (1), the curing temperature is 65-73 ℃, and the holding temperature is 220-240 ℃.

Technical Field

The invention relates to the technical field of graphite flakes, in particular to a high-heat-conductivity synthetic graphite flake with double-sided adhesion and a preparation method thereof.

Background

The graphite flake is a brand new heat-conducting and heat-dissipating material, has unique crystal grain orientation, conducts heat uniformly along two directions, and the lamellar structure can be well adapted to any surface, shield heat sources and components and simultaneously improve the performance of consumer electronic products. The novel natural graphite solution has high heat dissipation efficiency, small occupied space and light weight, conducts heat uniformly along two directions, eliminates a 'hot spot' area, shields a heat source and components and improves the performance of consumer electronic products.

Graphite flakes in the prior art are brittle and have poor thermal conductivity in the longitudinal direction (thickness direction), so that the overall heat dissipation performance is relatively general. To solve the above problems, a double-sided bonded high thermal conductive synthetic graphite sheet and a method for preparing the same are proposed.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a double-sided bonded high-heat-conductivity synthetic graphite sheet and a preparation method thereof, so as to overcome the problems mentioned in the background art.

In order to achieve the above purpose, the technical scheme of the invention is realized by the following technical scheme: a double-sided bonded high-thermal-conductivity synthetic graphite sheet comprises the following raw materials in parts by weight: 60-70 parts of graphite flakes, 15-25 parts of modified carbon fibers and 3-5 parts of heat conducting glue.

Preferably, the graphite sheet is prepared by the following steps: s1: crushing the carbon black, and removing iron impurities from the crushed carbon black through a magnetic separator; s2: and (4) putting the carbon black subjected to impurity removal into a graphitization furnace for graphitization treatment to obtain graphite flakes.

Preferably, the graphitization treatment temperature is 2200-2500 ℃, the pressure is 3-4MPa, and the time is 3-5 h.

Preferably, the particle diameter of the carbon black after pulverization is 0.1 to 0.3 mm.

Preferably, the preparation method of the modified carbon fiber comprises the following steps: 1) ultrasonically cleaning carbon fibers by using 75 wt% ethanol solution for 15-20min, washing the carbon fibers by using deionized water for 2-3 times, and then drying the carbon fibers; 2) and (3) putting the dried carbon fiber into vacuum evaporation equipment, putting a copper source into an evaporation chamber, and plating copper on the surface of the carbon fiber to form a copper coating to obtain the modified carbon fiber.

Preferably, the heating temperature of the copper source is 2590-2600 ℃, and the thickness of the copper plating layer is 5-7 μm.

The invention also provides a preparation method of the double-sided adhesive high-thermal-conductivity synthetic graphite sheet, which specifically comprises the following steps:

(1) mixing graphite flakes, modified carbon fibers and heat-conducting glue in proportion, placing the mixture into a mold, pressing and molding the mixture, taking the mixture out, placing the mixture into a thermostat for curing, then preserving heat for 1-2 hours, and cooling to obtain a high-heat-conductivity synthetic graphite flake;

(2) coating a layer of double-sided adhesive tape on both sides of the high-thermal-conductivity synthetic graphite sheet, and adhering a layer of release paper on the double-sided adhesive tape to obtain the double-sided adhesive high-thermal-conductivity synthetic graphite sheet.

Preferably, in the step (1), the thickness of the high thermal conductive synthetic graphite sheet is 0.02 to 0.05 mm.

Preferably, in the step (1), the curing temperature is 65-73 ℃, and the heat preservation temperature is 220-240 ℃.

The invention has the beneficial effects that:

according to the invention, the carbon fiber and the copper powder are added, and the copper is plated on the surface of the carbon fiber by adopting a vacuum evaporation method, so that the thickness of a copper plating layer is 5-7 μm, modified carbon fiber is formed, the strength of the carbon fiber is improved, meanwhile, the modified carbon fiber and the graphite flake are mixed and pressed into the high-heat-conductivity synthetic graphite flake, the copper powder on the modified carbon fiber is also inserted among the graphite flakes, the heat dissipation performance of the copper powder is better, the heat conductivity of the high-heat-conductivity synthetic graphite flake along the thickness direction is improved, and the integral heat conductivity of the high-heat-conductivity synthetic graphite flake is also improved;

according to the invention, the graphite flakes and the modified carbon fibers are mixed, after the carbon black is graphitized, the thermal conductivity is improved but the strength is reduced, the added modified carbon fibers are inserted among the graphite flakes, and after pressing, the overall performance of the graphite flakes is improved; meanwhile, the addition of the modified carbon fibers is also beneficial to improving the heat dissipation performance of the graphite flake.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

A double-sided bonded high-thermal-conductivity synthetic graphite sheet comprises the following raw materials in parts by weight: 65 parts of graphite flakes, 20 parts of modified carbon fibers and 4 parts of heat conducting glue.

The preparation method of the graphite flake comprises the following steps: s1: crushing the carbon black, and removing iron impurities from the crushed carbon black through a magnetic separator; s2: putting the carbon black subjected to impurity removal into a graphitization furnace for graphitization treatment to obtain graphite flakes; the temperature of the graphitization treatment is 2200 ℃, the pressure is 4MPa, and the time is 5 h; the particle diameter of the carbon black after being crushed is 0.1-0.3 mm.

The preparation method of the modified carbon fiber comprises the following steps: 1) ultrasonically cleaning carbon fibers for 15min by using 75 wt% ethanol solution, washing the carbon fibers for 2 times by using deionized water, and then drying the carbon fibers; 2) putting the dried carbon fiber into vacuum evaporation equipment, putting a copper source into an evaporation chamber, and plating copper on the surface of the carbon fiber to form a copper coating to obtain a modified carbon fiber; the heating temperature of the copper source was 2590 ℃ and the thickness of the copper plating layer was 6 μm.

The preparation method of the double-sided bonded high-thermal-conductivity synthetic graphite sheet comprises the following steps:

(1) mixing graphite flakes, modified carbon fibers and heat-conducting glue in proportion, placing the mixture into a mold, pressing and molding the mixture, taking the mixture out, placing the mixture into a thermostat, curing the mixture at 70 ℃, then preserving heat for 1 hour at 220 ℃, and cooling the mixture to obtain a high-heat-conductivity synthetic graphite flake, wherein the thickness of the high-heat-conductivity synthetic graphite flake is 0.03 mm;

(2) coating a layer of double-sided adhesive tape on both sides of the high-thermal-conductivity synthetic graphite sheet, and adhering a layer of release paper on the double-sided adhesive tape to obtain the double-sided adhesive high-thermal-conductivity synthetic graphite sheet.

Example 2

A double-sided bonded high-thermal-conductivity synthetic graphite sheet comprises the following raw materials in parts by weight: 60 parts of graphite flakes, 15 parts of modified carbon fibers and 3 parts of heat-conducting glue.

The preparation method of the graphite flake comprises the following steps: s1: crushing the carbon black, and removing iron impurities from the crushed carbon black through a magnetic separator; s2: putting the carbon black subjected to impurity removal into a graphitization furnace for graphitization treatment to obtain graphite flakes; the temperature of the graphitization treatment is 2500 ℃, the pressure is 3MPa, and the time is 5 h; the particle diameter of the carbon black after being crushed is 0.1-0.3 mm.

The preparation method of the modified carbon fiber comprises the following steps: 1) ultrasonically cleaning carbon fibers for 15min by using 75 wt% ethanol solution, washing the carbon fibers for 2 times by using deionized water, and then drying the carbon fibers; 2) putting the dried carbon fiber into vacuum evaporation equipment, putting a copper source into an evaporation chamber, and plating copper on the surface of the carbon fiber to form a copper coating to obtain a modified carbon fiber; the heating temperature of the copper source was 2600 ℃ and the thickness of the copper plating layer was 5 μm.

The preparation method of the double-sided bonded high-thermal-conductivity synthetic graphite sheet comprises the following steps:

(1) mixing graphite flakes, modified carbon fibers and heat-conducting glue in proportion, placing the mixture into a mold, pressing and molding the mixture, taking the mixture out, placing the mixture into a thermostat, curing the mixture at 70 ℃, then preserving heat for 1 hour at 230 ℃, and cooling the mixture to obtain a high-heat-conductivity synthetic graphite flake, wherein the thickness of the high-heat-conductivity synthetic graphite flake is 0.03 mm;

(2) coating a layer of double-sided adhesive tape on both sides of the high-thermal-conductivity synthetic graphite sheet, and adhering a layer of release paper on the double-sided adhesive tape to obtain the double-sided adhesive high-thermal-conductivity synthetic graphite sheet.

Example 3

A double-sided bonded high-thermal-conductivity synthetic graphite sheet comprises the following raw materials in parts by weight: 70 parts of graphite flake, 20 parts of modified carbon fiber and 5 parts of heat conducting glue.

The preparation method of the graphite flake comprises the following steps: s1: crushing the carbon black, and removing iron impurities from the crushed carbon black through a magnetic separator; s2: putting the carbon black subjected to impurity removal into a graphitization furnace for graphitization treatment to obtain graphite flakes; the temperature of the graphitization treatment is 2500 ℃, the pressure is 3MPa, and the time is 5 h; the particle diameter of the carbon black after being crushed is 0.1-0.3 mm.

The preparation method of the modified carbon fiber comprises the following steps: 1) ultrasonically cleaning carbon fibers for 15min by using 75 wt% ethanol solution, washing the carbon fibers for 2 times by using deionized water, and then drying the carbon fibers; 2) putting the dried carbon fiber into vacuum evaporation equipment, putting a copper source into an evaporation chamber, and plating copper on the surface of the carbon fiber to form a copper coating to obtain a modified carbon fiber; the heating temperature of the copper source was 2600 ℃ and the thickness of the copper plating layer was 5 μm.

The preparation method of the double-sided bonded high-thermal-conductivity synthetic graphite sheet comprises the following steps:

(1) mixing graphite flakes, modified carbon fibers and heat-conducting glue in proportion, placing the mixture into a mold, pressing and molding the mixture, taking the mixture out, placing the mixture into a thermostat, curing the mixture at 70 ℃, then preserving heat for 1 hour at 230 ℃, and cooling the mixture to obtain a high-heat-conductivity synthetic graphite flake, wherein the thickness of the high-heat-conductivity synthetic graphite flake is 0.03 mm;

(2) coating a layer of double-sided adhesive tape on both sides of the high-thermal-conductivity synthetic graphite sheet, and adhering a layer of release paper on the double-sided adhesive tape to obtain the double-sided adhesive high-thermal-conductivity synthetic graphite sheet.

Example 4

A double-sided bonded high-thermal-conductivity synthetic graphite sheet comprises the following raw materials in parts by weight: 65 parts of graphite flakes, 25 parts of modified carbon fibers and 3 parts of heat-conducting glue.

The preparation method of the graphite flake comprises the following steps: s1: crushing the carbon black, and removing iron impurities from the crushed carbon black through a magnetic separator; s2: putting the carbon black subjected to impurity removal into a graphitization furnace for graphitization treatment to obtain graphite flakes; the temperature of the graphitization treatment is 2500 ℃, the pressure is 3.5MPa, and the time is 5 h; the particle diameter of the carbon black after being crushed is 0.1-0.3 mm.

The preparation method of the modified carbon fiber comprises the following steps: 1) ultrasonically cleaning carbon fibers for 20min by using 75 wt% ethanol solution, washing the carbon fibers for 2 times by using deionized water, and then drying the carbon fibers; 2) putting the dried carbon fiber into vacuum evaporation equipment, putting a copper source into an evaporation chamber, and plating copper on the surface of the carbon fiber to form a copper coating to obtain a modified carbon fiber; the heating temperature of the copper source was 2600 ℃ and the thickness of the copper plating layer was 7 μm.

The preparation method of the double-sided bonded high-thermal-conductivity synthetic graphite sheet comprises the following steps:

(1) mixing graphite flakes, modified carbon fibers and heat-conducting glue in proportion, placing the mixture into a mold, pressing and molding the mixture, taking the mixture out, placing the mixture into a thermostat, curing the mixture at 70 ℃, then preserving heat for 1 hour at 230 ℃, and cooling the mixture to obtain a high-heat-conductivity synthetic graphite flake, wherein the thickness of the high-heat-conductivity synthetic graphite flake is 0.02 mm;

(2) coating a layer of double-sided adhesive tape on both sides of the high-thermal-conductivity synthetic graphite sheet, and adhering a layer of release paper on the double-sided adhesive tape to obtain the double-sided adhesive high-thermal-conductivity synthetic graphite sheet.

Example 5

A double-sided bonded high-thermal-conductivity synthetic graphite sheet comprises the following raw materials in parts by weight: 68 parts of graphite sheet, 22 parts of modified carbon fiber and 4 parts of heat conducting glue.

The preparation method of the graphite flake comprises the following steps: s1: crushing the carbon black, and removing iron impurities from the crushed carbon black through a magnetic separator; s2: putting the carbon black subjected to impurity removal into a graphitization furnace for graphitization treatment to obtain graphite flakes; the temperature of the graphitization treatment is 2300 ℃, the pressure is 3.5MPa, and the time is 5 h; the particle diameter of the carbon black after being crushed is 0.1-0.3 mm.

The preparation method of the modified carbon fiber comprises the following steps: 1) ultrasonically cleaning carbon fibers for 20min by using 75 wt% ethanol solution, washing the carbon fibers for 2 times by using deionized water, and then drying the carbon fibers; 2) putting the dried carbon fiber into vacuum evaporation equipment, putting a copper source into an evaporation chamber, and plating copper on the surface of the carbon fiber to form a copper coating to obtain a modified carbon fiber; the heating temperature of the copper source was 2600 ℃ and the thickness of the copper plating layer was 6 μm.

The preparation method of the double-sided bonded high-thermal-conductivity synthetic graphite sheet comprises the following steps:

(1) mixing graphite flakes, modified carbon fibers and heat-conducting glue in proportion, placing the mixture into a mold, pressing and molding the mixture, taking the mixture out, placing the mixture into a thermostat, curing the mixture at 73 ℃, then preserving heat for 2 hours at 240 ℃, and cooling the mixture to obtain a high-heat-conductivity synthetic graphite flake, wherein the thickness of the high-heat-conductivity synthetic graphite flake is 0.05 mm;

(2) coating a layer of double-sided adhesive tape on both sides of the high-thermal-conductivity synthetic graphite sheet, and adhering a layer of release paper on the double-sided adhesive tape to obtain the double-sided adhesive high-thermal-conductivity synthetic graphite sheet.

Performance detection

The test method comprises the following steps: the thermal conductivities of the high thermal conductive synthetic graphite sheets of examples 1 to 5 were measured by a laser method, respectively. Specific detection results are shown in table 1.

TABLE 1 thermal conductivity

Group of	Transverse thermal conductivity (W/m. k)	Longitudinal thermal conductivity (W/m.k)
			Example 1	1486	78
Example 2	1501	75
			Example 3	1498	76
Example 4	1510	89
			Example 5	1482	62

As can be seen from the above table, the high thermal conductive synthetic graphite sheet of the present invention is excellent in thermal conductivity.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.