Thermally conductive and insulating composite material and preparation method thereof

Abstract

The invention discloses a thermally conductive and insulating composite material and a preparation method thereof. The composite material comprises the following components in parts by weight: 100 parts of a polymer matrix and 5-33 parts of a modified carbon-based filler, wherein the modified carbon-based filler is formed by conducting secondary coating modification on a carbon-based filler through an insulting metallic oxide. Through the secondary coating of the carbon-based filler, the coating rate of the carbon-based filler is improved, and thus a coating raw material can be utilized to the greatest extent; the composite material can keep high insulativity when the relatively high thermal conductivity of the composite material is ensured, so that the application range of the composite material is enlarged.

Description

technical field [0001] The invention belongs to the field of functional polymer materials, and in particular relates to a heat-conducting and insulating composite material and a preparation method thereof. Background technique [0002] Thermally conductive and insulating polymer materials are mainly composed of polymer insulating substrates and thermally conductive insulating fillers. According to the classification of the substrate, they can be roughly divided into: thermally conductive and insulating plastics, thermally conductive and insulating rubbers, thermally conductive and insulating adhesives, thermally conductive and insulating coatings, and others. [0003] At present, thermally conductive and insulating polymer materials can be mainly used in microelectronic packaging, motors, automobiles, special cables, high-end aerospace and other fields, and can replace traditional metals or metal alloys to manufacture heat exchangers, heat pipes, solar water heaters, and batt...

AI Technical Summary

Problems solved by technology

This application uses one-time coating to prepare insulating and heat-conducting powder, the coating rate is low, and the insulating and heat-conducting powder is reacted in a high-pressure reactor with a pressure of 5-20 standard atmospheres, which has potential production risks and is not conducive to production The monitoring and adjustment during the reaction process cannot guarantee the best coating conditions, which will obviously affect the final coating effect. In addition, the liquid organometallic compound used in this method is more expensive than the metal inorganic compound.

[0008] The Chinese patent application CN201410048639 discloses a graphene-containing insulating and heat-dissipating composition and its preparation. The insulating and heat-dissipating composition is hydrolyzed on the surface of graphene by tetraethyl orthosilicate, and the heat preservation reaction at 50-70°C 1- 3 hours, the produced silicic acid is coated on the surface of graphene, and then dried at 120-150°C for 2-6 hours, and finally a silicon dioxide film is formed on the surface of graphene to complete the modification of graphene. It is also modified by one-time coating of graphene, the coating rate is low, resulting in waste of coating raw materials, and although silica itself has excellent insulation properties, its thermal conductivity is too low (1.5 W / mK) will obviously cause It affects the excellent thermal conductivity of graphene itself. Therefore, the prepared modified graphene also needs to be mixed with other insulating and thermally conductive fillers under the action of surface treatment agents and functional additives to form an insulating and thermally conductive composition synergistically.

This will obviously increase the process flow, the process is more complicated, it will also affect the production stability of the product, and increase the production cost

In addition, the cost of the selected raw material ethyl orthosilicate is relatively high, which is not conducive to reducing the production cost of the final product for industrial production.

Images