Preparation and application of mica powder

 For the preparation of high diameter-thickness ratio mica powder

At present, there are many methods for preparing high diameter-thickness ratio mica powder, among which one of the more commonly used preparation methods is to use sodium hydroxide to intercalate and swell the mica powder, and then to strip and grind it. However, this method has many drawbacks, for example, in the process of intercalation and expansion of mica powder with sodium hydroxide, heating and ultrasonic treatment are required, and this process is technically difficult and costly.

CN201610721799.2 provides a method for preparing mica powder with high diameter-thickness ratio, which solves the problem of technical difficulty and high cost of the process in which heating and ultrasonic treatment are required in the process of intercalation and expansion treatment of mica powder using sodium hydroxide.

In order to solve the above technical problems, the technical solution used is: it includes the following steps.

A. slurrying raw mica powder with water at a solid-to-liquid ratio of 1:3 to 5 to produce a mica powder slurry.

B. adding urea supersaturated solution to the mica powder slurry to produce mica powder intercalation solution; wherein said urea supersaturated solution is a supersaturated solution made of urea and water with a mass not less than the dry weight of the raw mica powder; C. diluting the mica powder intercalation solution with water to a solid-liquid ratio of 18-25:100 to produce mica powder intercalation dilution solution; D. diluting the mica powder intercalation solution with water to a solid-liquid ratio of 18-25:100.

D. Put the mica powder intercalation dilution solution into the colloid mill for stripping and grinding treatment.

The beneficial effects obtained by the present invention are.

1. By using urea as the intercalating agent, the present invention makes it possible to reduce the technical difficulty and production cost by eliminating the need for heating and ultrasonic treatment during the intercalation treatment of raw mica powder.

2. By adjusting the gap between the mill stator and the rotor of the colloid mill to the minimum, as well as adjusting the frequency converter output frequency to 50Hz, the present invention improves the Reynolds coefficient between the materials in the colloid mill, thereby improving its stripping effect.

Preparation of a thermoplastic mica powder for PVC plastics

PVC is the first and the second most common synthetic resin material in China and the world, and has become one of the most widely used plastics due to its high chemical stability and good plasticity. Large viscosity, poor fluidity, low thermal stability, easy to cause decomposition and other defects, there are PVC products with poor aging resistance, easy to become brittle, hard, cracking, toughness, poor cold resistance, etc., so it is generally necessary to modify PVC to make up for the above shortcomings.

In the inorganic mineral filler, mica powder with its unique two-dimensional sheet structure, high elasticity, high toughness, high temperature resistance and strong acid and alkali resistance, in engineering plastics, especially in engineering plastics have a wide range of applications, modified mica powder added to plastics can significantly improve the comprehensive performance of plastic products; mica with two-dimensional sheet structure in plastics can play a planar enhancement, modified products The performance of modified products is improved greatly and the uniform orientation does not warp and deform, which gives the products excellent dimensional stability. Improve the tensile strength, flexural strength and flexural modulus of plastics, and greatly improve their heat deflection temperature. Enhance the toughness of products, anti-aging and anti-cracking.

Chinese invention patent application No. 201410263311.7 discloses a preparation method of modified mica powder used as filler for rubber products, in order to solve the technical problems of the existing technology, such as the high surface energy of mica powder, which is easy to reunite when filled directly into rubber raw materials and difficult to play its reinforcing role. The surface modification of mica powder is carried out by using silane coupling agent, and the time and temperature of modification are controlled, so that the mica powder can be effectively dispersed into organic polymers, improve its compatibility with organic bodies, and give full play to its reinforcing effect.