The surface polarity of mica powder is large, the compatibility is poor, easy to agglomerate and uneven dispersion, so it is necessary to modify the surface of mica, in order to better play the characteristics of mica, while maintaining other properties of the material.
At present, the surface modification of mica powder mainly has two methods: organic surface modification and inorganic surface coating modification.
1. Organic surface modification of mica powder
Improve the compatibility of mica powder and polymer base material, improve its application performance.
Mica powder used as a reinforcing filler for polyolefins, polyamides and polyesters.
Silane coupling agent, butadiene, zirconium aluminate, silicone (oil), etc.
The mica used for surface modification is preferably a wet milled mica powder, and the most effective surface modifier is an aminosilane. However, the mixed use of two surface modifiers is often more effective, especially to improve the mechanical properties and thermal aging characteristics of polypropylene composites.
The surface treatment of mica powder can improve the mechanical strength of the material and reduce the molding shrinkage.
The amount of surface modifier is the key to affect the modification effect, and the variety of coupling agent also affects the application effect of mica surface modification treatment.
2. Inorganic surface modification of mica powder
Give mica powder good optical effect and visual effect, make the product more colorful and more elegant, so as to improve the application value of mica powder.
Used as coatings, inks, artificial leather, cosmetics, plastics, rubber, toys, printing and decoration, paper and other mica pigments.
Titanium oxide, chromium oxide, zirconium oxide, etc.
The coating of titanium dioxide and other oxides on the surface of mica to prepare pearlescent mica and colored mica is a precipitation reaction in an aqueous solution. Taking coated titanium dioxide as an example, the commonly used methods include titanium tetrachloride plus alkali method, organic acid titanium method, thermal hydrolysis method and buffer method. Commonly used coating agents are soluble titanium salts (titanium tetrachloride and titanyl sulfate).
The commercial names of such surface-modified mica powders are "pearlescent mica" and "colored mica". The raw material was wet ground mica powder in flake form.
Modification, surface, mica powder, mica, method, modifier, effect, improve, titanium oxide