阅读说明：本技术 一种碳化硅/氮化碳复合增强导热防水薄膜及其制备方法 (Silicon carbide/carbon nitride composite reinforced heat-conducting waterproof film and preparation method thereof ) 是由 薛名山 李坚 彭同华 罗一丹 殷祚炷 洪珍 谢宇 于 2020-10-12 设计创作，主要内容包括：本发明公开了一种SiC/C_3N_4复合增强导热防水薄膜及其制备方法,其特征在于包含以下步骤：首先,按照一定配比称取碳化硅、三聚氰胺,使用冷却结晶法制备前驱体,煅烧后获得SiC/C_3N_4复合物后备用；然后,将SiC/C_3N_4复合物均匀分散于三防漆中,配置导热防水浆料；最后,使用高压喷涂法在基材上喷涂导热浆料,经加热固化后形成具有优良导热性能的防水薄膜。本发明提供的制备方法,将高导热性能的SiC和C_3N_4复合合成SiC/C_3N_4复合物,均匀分散于三防漆中并喷涂成膜,使得最终形成的薄膜具有外观良好、均匀致密、防水、高导热的特点,且该制备工艺简单易操作,可大规模生产。(The invention discloses a SiC/C 3 N 4 The composite reinforced heat-conducting waterproof film and the preparation method thereof are characterized by comprising the following steps: firstly, silicon carbide and melamine are weighed according to a certain proportion, a precursor is prepared by using a cooling crystallization method, and SiC/C is obtained after calcination 3 N 4 Compounding for later use; then, SiC/C 3 N 4 Uniformly dispersing the compound in the three-proofing paint, and preparing heat-conducting waterproof slurry; finally, spraying heat-conducting slurry on the base material by using a high-pressure spraying method, and heating and curing to form the heat-conducting material with excellent heat-conducting propertyA waterproof film. The preparation method provided by the invention is used for preparing SiC and C with high heat conductivity 3 N 4 Composite synthesis of SiC/C 3 N 4 The compound is uniformly dispersed in the three-proofing paint and sprayed to form a film, so that the finally formed film has the characteristics of good appearance, uniformity, compactness, water resistance and high heat conductivity, and the preparation process is simple and easy to operate and can be used for large-scale production.)

1. SiC/C₃N₄Compound reinforcing heat conduction waterproof film, its characterized in that: the dense waterproof film contains highly dispersed SiC and C with high thermal conductivity₃N₄Composite synthetic SiC/C₃N₄The compound has the performance of enhancing heat conduction.

2. A SiC/C as claimed in claim 1₃N₄The preparation method of the composite reinforced heat-conducting waterproof film is characterized by comprising the following steps: the method comprises the following steps of,

step S1, preparing a precursor by using a cooling crystallization method, and obtaining SiC/C after high-temperature heat treatment₃N₄A complex;

step S2, mixing the SiC/C prepared in the step S1₃N₄The compound is uniformly dispersed in the three-proofing paint to obtain heat-conducting slurry;

and S3, spraying the heat-conducting slurry prepared in the step S2 on the surface of the base material by using high-pressure spraying equipment, and then putting the base material into a drying oven for curing the film layer to obtain the heat-conducting waterproof film.

3. SiC/C according to claim 2₃N₄The preparation method of the composite reinforced heat-conducting waterproof film is characterized by comprising the following steps: the step S1 includes the steps of:

(1) heating 90-98 parts by mass of deionized water to 95-100 ℃, adding 2.0-3.5 parts by mass of melamine into the deionized water, stirring for 5-10 min, weighing 0.01-0.035 parts by mass of SiC micropowder with the particle size of 200-500nm, adding the SiC micropowder into the melamine solution, and performing ultrasonic dispersion treatment for 30-60 min to obtain a dispersion liquid;

(2) carrying out suction filtration treatment on the dispersion liquid, drying the obtained powder at 70-80 ℃, fully grinding the powder, placing the powder in a crucible with a cover for heat treatment at 520-580 ℃ for 2-2.5 h to obtain SiC/C₃N₄And (c) a complex.

4. SiC/C according to claim 2₃N₄The preparation method of the composite reinforced heat-conducting waterproof film is characterized by comprising the following steps: the specific process of step S2 is: according to the mass fraction, 0.5-2.0 parts of SiC/C₃N₄And putting the compound into 98-99.5 parts of three-proofing paint, and performing ultrasonic dispersion treatment for 30-60 min to obtain the heat-conducting slurry.

5. SiC/C according to claim 2₃N₄The preparation method of the composite reinforced heat-conducting waterproof film is characterized by comprising the following steps: the three-proofing paint is selected from at least one of polyurethane system three-proofing paint, organic silicon system three-proofing paint and acrylic acid system three-proofing paint.

6. SiC/C according to claim 2₃N₄The preparation method of the composite reinforced heat-conducting waterproof film is characterized by comprising the following steps: in step S3, the spraying pressure is set at 0.2-0.5 MPa, and the spraying distance is controlled at 200-250 mm.

Technical Field

The invention relates to the technical field of films, in particular to SiC/C₃N₄A composite reinforced heat-conducting waterproof film and a preparation method thereof.

Background

In order to protect electronic products from environmental factors such as chemistry, humidity, high temperature, etc. during storage, transportation and use, people usually cover a layer of protective film on the surface of the electronic products to protect the electronic components and prolong the service life of the electronic components and parts. However, in order to pursue the reliability of the protection effect, the protection layer with a certain thickness needs to bear a higher temperature condition in the protection process, which causes the protection layer to catch the toggle in the aspects of heat transfer, heat conduction and heat dissipation, but accelerates the aging, cracking, hardening and the like of the protection layer, affects the performance of the electronic product, and shortens the service life of the electronic product. SiC has a thermal conductivity as high as 83.6W/m.K, besides being chemically stable, small in thermal expansion coefficient and good in wear resistance, and has a special space as a thermal conductive additive. Graphite phase carbon nitride g-C with unique structure₃N₄Stable chemical performance, capability of absorbing visible light, good thermal stability and wear resistance, no toxicity, rich sources and simple preparation and forming process. Mixing SiC with C₃N₄The composite is added into the functional polymer film, which is helpful for improving the chemical stability, the wear resistance and the heat conduction and radiation performance of the film, and particularly makes up the problems of aging and hardening of organic materials due to heat, thereby obviously improving the radiation performance of the film material and improving the reliability.

Disclosure of Invention

The invention aims to solve the problems that: provide aSeed SiC/C₃N₄A composite reinforced heat-conducting waterproof film prepared from SiC and C with high heat-conducting performance₃N₄Composite synthesis of SiC/C₃N₄The compound is uniformly dispersed in the three-proofing paint and sprayed to form a film, so that the finally formed film has the characteristics of good appearance, uniformity, compactness, water resistance and high heat conductivity, and the preparation process is simple and easy to operate and can be used for large-scale production.

The technical scheme provided by the invention for solving the problems is as follows: SiC/C₃N₄The compact waterproof film comprises highly dispersed SiC and C with high thermal conductivity₃N₄Composite synthetic SiC/C₃N₄The compound has the performance of enhancing heat conduction.

Preferably, the method comprises the steps of,

step S1, preparing a precursor by using a cooling crystallization method, and obtaining SiC/C after high-temperature heat treatment₃N₄A complex;

step S2, mixing the SiC/C prepared in the step S1₃N₄The compound is uniformly dispersed in the three-proofing paint to obtain heat-conducting slurry;

and S3, spraying the heat-conducting slurry prepared in the step S2 on the surface of the base material by using high-pressure spraying equipment, and then putting the base material into a drying oven for curing the film layer to obtain the heat-conducting waterproof film.

Preferably, the step S1 includes the steps of:

(1) heating 90-98 parts by mass of deionized water to 95-100 ℃, adding 2.0-3.5 parts by mass of melamine into the deionized water, stirring for 5-10 min, weighing 0.01-0.035 parts by mass of SiC micropowder with the particle size of 200-500nm, adding the SiC micropowder into the melamine solution, and performing ultrasonic dispersion treatment for 30-60 min to obtain a dispersion liquid;

(2) carrying out suction filtration treatment on the dispersion liquid, drying the obtained powder at 70-80 ℃, fully grinding the powder, placing the powder in a crucible with a cover for heat treatment at 520-580 ℃ for 2-2.5 h to obtain SiC/C₃N₄And (c) a complex.

Preferably, the specific process of step S2Comprises the following steps: according to the mass fraction, 0.5-2.0 parts of SiC/C₃N₄And putting the compound into 98-99.5 parts of three-proofing paint, and performing ultrasonic dispersion treatment for 30-60 min to obtain the heat-conducting slurry.

Preferably, the three-proofing paint is selected from at least one of polyurethane system three-proofing paint, organosilicon system three-proofing paint and acrylic acid system three-proofing paint.

Preferably, in step S3, the spraying pressure is set to 0.2-0.5 MPa, and the spraying distance is controlled to 200-250 mm.

Compared with the prior art, the invention has the advantages that:

1. SiC/C provided by the invention₃N₄The compound has the characteristics of high purity, excellent heat conductivity and good dispersibility.

2. The waterproof heat-conducting film provided by the invention has a compact and uniform three-proofing paint film layer, ensures a stable waterproof effect, and simultaneously contains high-heat-conducting SiC and C₃N₄Composite synthetic SiC/C₃N₄The composite has enhanced heat conduction performance.

3. The preparation method provided by the invention is simple and easy to operate, has low production cost and no environmental pollution, and can realize large-scale production.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.

FIG. 1 shows SiC/C of the present invention for preparing heat conductive waterproof film₃N₄The surface of the compound emits the scanning electron microscope picture in the field;

FIG. 2 is a schematic diagram of SiC/C spray coating on a PCB₃N₄And compounding a physical photograph of the reinforced heat-conducting waterproof film.

Detailed Description

The embodiments of the present invention will be described in detail with reference to the accompanying drawings and examples, so that how to implement the technical means for solving the technical problems and achieving the technical effects of the present invention can be fully understood and implemented.

Example 1

Weighing 97 parts of deionized water, heating to 99 ℃, putting 2.97 parts of melamine into the deionized water, stirring for 10min, weighing 0.03 part of SiC micropowder, putting the SiC micropowder into the melamine solution, and performing ultrasonic dispersion treatment for 50min to obtain a dispersion liquid. Filtering the dispersion, drying the obtained powder at 80 deg.C, grinding, and heat treating at 55 deg.C for 2 hr in a crucible with a cover to obtain SiC/C₃N₄And (c) a complex. Weighing 0.5 part of SiC/C₃N₄And putting the compound into 99.5 parts of three-proofing paint, and performing ultrasonic dispersion treatment for 50min to obtain the heat-conducting slurry. And (3) spraying the heat-conducting slurry onto the surface of the base material by using high-pressure spraying equipment (the spraying air pressure is set to be 0.4MPa, and the spraying distance is controlled to be 200mm), then placing the base material into a drying box with the set temperature of 50 ℃ for curing the film layer for 36 hours to obtain a first heat-conducting waterproof film, recording the first heat-conducting waterproof film as a sample I, and measuring the heat conductivity of the first sample I to be 1.533W/m.K by using a heat conductivity coefficient tester.

Example 2

A thermally conductive paste was prepared as in example 1, except that SiC/C was used₃N₄The mass ratio of the compound to the three-proofing paint is 1: 99, and the prepared heat-conducting waterproof film is marked as sample two.

Example 3

A thermally conductive paste was prepared as in example 1, except that SiC/C was used₃N₄The mass ratio of the compound to the three-proofing paint is 1.5: 98.5, and the prepared heat-conducting waterproof film is marked as sample three.

Example 4

A thermally conductive paste was prepared as in example 1, except that SiC/C was used₃N₄The mass ratio of the compound to the three-proofing paint is 3: 97, and the prepared heat-conducting waterproof film is marked as sample four.

Example 5

A film was prepared as in example 1, except that a three-proofing paint was directly sprayed on the surface of the substrate, and the resulting water-repellent film was designated sample five.

Detection example 1

The samples obtained in the above experimental examples were subjected to a thermal conductivity test using a thermal conductivity meter to measure the samples, and the specific results are shown in table 1.

Detection example 2

The sample obtained in the above embodiment is subjected to a waterproof test, and the specific method is as follows: preparing a heat-conducting waterproof film on a hardboard, spraying some water on the surface of the hardboard, standing for 1 hour and observing whether the water seepage phenomenon exists.

TABLE 1

Sample (I)	Thermal conductivity	Whether or not to be infiltrated
			Sample No	1.533	Whether or not
Sample No. 2	1.496	Whether or not
			Sample No. three	1.992	Whether or not
Sample No. 4	1634	Whether or not
			Sample five	0.223	Whether or not

The foregoing is merely illustrative of the preferred embodiments of the present invention and is not to be construed as limiting the claims. The present invention is not limited to the above embodiments, and the specific structure thereof is allowed to vary. All changes which come within the scope of the invention as defined by the independent claims are intended to be embraced therein.