Preparation method of mica paper with high thermal conductivity

Abstract

The invention discloses a preparation method of a mica paper with high thermal conductivity. The preparation method comprises following steps: step one, picking mica: removing disqualified raw materials, and picking mica sheets with an area not greater than 10 cm2 and a thickness not greater than 2 cm; step two, preparing mica slurry: uniformly delivering mica sheets picked in the step one to a high pressure hydraulic grinding machine, grinding, filtering, grading, and dehydrating to obtain fine mica slurry; step three, preparing a highly conductive filler solution: adding water into a filler to dilute the filler and stirring the filler by a stirring machine; step four, papermaking: using a rotary screen mica papermaking machine to carry out papermaking, wherein rotary screen sizing is performed for five times, and each time, after rotary screen sizing, the highly conductive filler solution prepared in the step three is sprayed on the mica paper; and step five, dehydrating and drying: after spraying, carrying out dehydrating and drying to obtain the mica paper with high thermal conductivity. The prepared mica paper with high thermal conductivity has the advantages that the using amount of fillers is small, the fillers are uniformly distributed, the thermal conductive performance is strong, the mechanical properties are good, and the service life is long.

Description

Technical field [0001] The invention belongs to the field of high thermal conductivity insulating materials, and more specifically is a method for preparing high thermal conductivity mica paper. Background technique [0002] In the current situation, with the development of the power system, mankind's demand for motors is increasing. Large and medium-sized high-voltage motors are constantly expanding their capacity and withstand voltage. However, with the operation of large and medium-sized high-voltage motors, a large amount of heat is generated inside the equipment and cannot be discharged in time, resulting in excessively high temperature of the motor, increased loss and greatly reduced service life. According to data, if the working temperature of the electronic component itself can be reduced by 10°C, its service life can be doubled. Therefore, large and medium-sized high-voltage motors have increasingly higher requirements for the thermal conductivity of the insulating la...

AI Technical Summary

Problems solved by technology

This is because pure zero-dimensional α-Al 2 o 3 When used as a filler, if the content of thermally conductive filler is insufficient, the filler particles cannot contact each other, so the zero-dimensional α-Al 2 o 3 It is necessary to exchange heat with the base material. Due to the existence of interface thermal resistance, the thermal conductivity is reduced. Only when the zero-dimensional α-Al 2 o 3 When the concentration is large enough to form a cross-linked network, heat can be effectively transferred, but due to the 2 o 3 High density, easy to precipitate and layer in silicone resin, high concentration of Al 2 o 3 This phenomenon is exacerbated, and some studies have shown that adding Al to the resin 2 o 3 , will accelerate the aging of this insulating material, thereby shortening the service life of the entire mica paper-based insulating material

And Nano Al 2 o 3 Expensive, high concentration of Al 2 o 3 Directly raised the overall price of high thermal conductivity mica paper-based composite materials

At the same time, since Al 2 o 3 It is diffused into the mica paper through the silicone resin, and its distribution is not uniform, causing the electrical properties of the mica paper to be negatively affected and decreased

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