CN-122011779-A - Heat-conducting silicon paste treated by propyl trimethoxy silane oligomer and preparation method thereof

CN122011779ACN 122011779 ACN122011779 ACN 122011779ACN-122011779-A

Abstract

The invention relates to the technical field of heat-conducting interface materials and discloses a high heat-conducting silicon paste for surface treatment of propyl trimethoxy silane oligomer and a preparation method thereof. The aluminum oxide filler is subjected to surface treatment by using the propyl trimethoxy silane oligomer, so that the comprehensive performance of the silicon paste is obviously improved. Compared with a sample without adding treatment, when the propyl trimethoxysilane oligomer is used, the heat conductivity coefficient of the silicon paste filled with 70vol% of aluminum oxide is improved by more than 70%, the heat resistance is reduced by about 50%, the cone penetration is obviously increased, and the thermal interface material with low cost, high heat conductivity coefficient and low heat resistance is obtained. The preparation method disclosed by the invention is simple in process and easy for industrial production.

Inventors

WU CHUAN
LI CHENCHEN
ZHOU XIANG
WANG YULIN
NING CHENG
HUANG LIANGBING
HU JIAQI

Assignees

浙江开化合成材料有限公司
浙江新安化工集团股份有限公司
杭州师范大学
浙江开化七一电器股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260310

Claims (8)

1. The heat-conducting silicon paste treated by the propyl trimethoxy silane oligomer is characterized by being prepared from the following components in parts by weight: (1) 100 parts by weight of vinyl silicone oil; (2) 880-1020 parts by weight of alumina filler; (3) Propyl trimethoxy silane oligomer in an amount of 1.5 to 2.5wt% of the alumina filler.
2. The heat-conducting silicone paste treated by the propyltrimethoxysilane oligomer according to claim 1, wherein the densities of the vinyl silicone oil and the propyltrimethoxysilane oligomer are calculated according to 0.96 g/cm 3 , the density of the alumina filler is calculated according to 4.0 g/cm 3 , the volume fraction of the alumina filler in the heat-conducting silicone paste is 65% -75%, the amount of the propyltrimethoxysilane oligomer is 2.0 wt% of the mass of the alumina filler, and the volume fraction of the alumina filler filled in the heat-conducting silicone paste is 70%.
3. A method for preparing the heat-conducting silicone paste treated by the propyl trimethoxysilane oligomer as claimed in claim 1, which is characterized by comprising the following specific steps: The surface treating agent is prepared by taking vinyl silicone oil with the dynamic viscosity of 100 mPa and a seed s at 25 ℃ as a matrix, adopting aluminum oxide heat conducting filler as heat conducting filler, taking propyl trimethoxy silane oligomer as surface treating agent of the aluminum oxide heat conducting filler, dispersing at high speed, and decompressing and degassing.
4. The method for preparing a heat conductive silicone paste treated with propyltrimethoxysilane oligomer as recited in claim 3, wherein the alumina filler has a particle size of 70 μm.
5. The method for preparing the heat-conducting silicone paste treated by the propyl trimethoxysilane oligomer according to claim 3, wherein the propyl trimethoxysilane oligomer is prepared by the following steps: (1) Adding propyl trimethoxy silane and a methanol solvent into a three-neck flask provided with a reflux condenser, a thermometer and a stirring device; (2) Heating the mixture to 35-50 ℃ under stirring, and then dripping a mixed solution consisting of methanol, hydrochloric acid and water which are prepared in advance into a flask; (3) After the aging reaction is finished, cooling the mixture to room temperature, and then adjusting the pH value of the mixture to 7-8 by using sodium bicarbonate; (4) And heating the filtered filtrate at the normal pressure at the speed of 5-10 ℃ per minute until the solvent is completely distilled off, and cooling the mixture to room temperature to obtain the propyl trimethoxy silane oligomer.
6. The method for preparing a heat-conductive silicone paste treated with an oligomer of propyltrimethoxysilane according to claim 5, wherein in the step (1), the mass ratio of methanol to propyltrimethoxysilane is (1/3-1): 1.
7. The method for preparing the heat-conducting silicone paste treated by the propyltrimethoxysilane oligomer according to claim 5, wherein in the step (2), the mass ratio of methanol to water is (1-3) 1, the mass ratio of hydrochloric acid is 1-8% of the mass of propyltrimethoxysilane, the molar ratio of water to propyltrimethoxysilane is (0.3-2.1) 1, and the dripping time of the mixed solution is 10-60 min.
8. The method for preparing a heat-conductive silicone paste treated with a propyltrimethoxysilane oligomer according to claim 5, wherein in the step (3), the aging reaction temperature is 60-90 ℃ and the aging reaction time is 2-10 hours.

Description

Heat-conducting silicon paste treated by propyl trimethoxy silane oligomer and preparation method thereof Technical Field The invention relates to the technical field of thermal interface materials, in particular to a heat-conducting silicon paste taking propyl trimethoxy silane oligomer as a surface treating agent and vinyl silicone oil as a matrix and a preparation method thereof. Background With the continuous increase of power density of electronic devices, heat dissipation has become a key factor in limiting performance and reliability. The heat conducting silicon paste is used as a thermal interface material filled between the heating source and the radiator, and has the core function of removing interface air and constructing a high-efficiency heat conducting channel. The performance of the thermally conductive silicone paste is mainly determined by the polymer matrix and the thermally conductive filler. At present, most commercial heat-conducting silicon pastes adopt dimethyl silicone oil as a matrix material, but the interface compatibility between the dimethyl silicone oil and the filler is poor, so that the improvement of the filling quantity of the filler is limited, and the problems of silicone oil precipitation, heat resistance increase and the like occur in the long-term use process. In order to improve the interfacial compatibility of the filler with the matrix, the filler is generally surface-treated with a silane coupling agent. However, conventional small molecule silane coupling agents (e.g., KH-550, KH-560, etc.) are volatile and migrate in high temperature environments, resulting in reduced interfacial stability, affecting the durability of thermal conductivity. Silane oligomers are considered to be a new generation of highly effective surface treatments due to their high boiling point, low volatility and high functional group density. Chinese patent application CN111763321a discloses a preparation method of propylsilane oligomer, the application field of the oligomer is building waterproof material, and the heat conduction interface material is not involved, and especially the dispersion of the heat conduction filler after oligomer treatment in specific matrix silicone oil and the influence of the heat conduction filler on the heat conduction performance of the heat interface material are not considered. In the prior art, the heat conduction silicon paste prepared by adopting the simethicone as a matrix and filling the heat conduction filler treated by the conventional silane coupling agent is generally low in heat conduction coefficient which is mostly lower than 2.0W/(m.K), and the prepared silicon paste is small in taper degree, so that low heat resistance and good construction flexibility are difficult to be simultaneously considered. While high thermal conductivity thermal interface materials can be prepared using alkoxy mono-terminated polysiloxanes, alkoxy mono-terminated polysiloxanes are expensive, resulting in a lack of market competitiveness for the thermal interface materials. Therefore, development of the novel heat-conducting silicon paste which is low in cost and capable of simultaneously realizing high heat conduction, low thermal resistance and excellent workability has wide market prospect. Disclosure of Invention The invention aims to provide a heat-conducting silicone paste treated by propyl trimethoxy silane oligomer and a preparation method thereof, and aims to overcome the defects of safety and technology existing in the prior art of directly using a micromolecule silane coupling agent or a cross-linking agent as a heat-conducting filler treating agent, and provide a low-cost high-performance heat-conducting silicone paste and a preparation method thereof. The heat-conducting silicon paste adopts specific propyl trimethoxy silane oligomer to carry out surface treatment on the heat-conducting filler, and adopts vinyl silicone oil as a matrix and aluminum oxide as the filler, so that the cooperative optimization of heat conductivity coefficient, thermal impedance and cone penetration is realized. The invention adopts the following technical scheme: The heat-conducting silicone paste is prepared from the following components in parts by weight: (1) 100 parts by weight of vinyl silicone oil; (2) 880-1020 parts by weight of alumina filler; (3) The amount of the propyl trimethoxy silane oligomer is 1.5-2.5% of the total weight of the alumina filler. The heat-conducting silicon paste is prepared by the following method: (1) Placing vinyl silicone oil with 25 ℃ dynamic viscosity of 100 mPa ℃ and s as a matrix and propyl trimethoxy silane oligomer into a container, placing the container into a non-invasive homogenizer, and mixing 1min under the conditions of 1800 rpm rotating speed and relative vacuum degree of-99.5 kPa to uniformly mix the vinyl silicone oil and the oligomer; (2) Filling alumina filler into a container, putting the container into a homogenizer again, an