why aluminium paste get dark ?
why aluminium powder get dark ?
due to aluminium paste have excellent reflect powder with metallic glossy , the surface Can be change effect .
windly use for car paint , metallic industrial coating , boat coating ,heat resistant coatings and other aspects have a very wide range of applications.
However, the aluminum paste is easily oxidized or polluted in the process of production, resulting in blackened and tarnished products.
1 Pollution. Aluminum paste susceptible to contamination in screening or other processes, or the product will become black and lose luster because of contamination caused by other metal impurities.
2. The oxidation. Aluminum paste is easy to be oxidized, vulcanized or alcoholized in the production process, which leads to blackening of the product and affects the appearance of the paint film.
3. Other additives. Due to the addition of dispersant or other additives containing double bonds, the aluminum paste is coarsened under the action of oxygen by aerobic polymerization. In addition to the above aspects, there are other causes of loss of light and blackening. Our recommended solution for aluminum paste aging is to use phosphite ester antioxidants, which can effectively prevent free radical polymerization, and also chelate impurities metal ions to prevent oxidation and discoloration of products. The acid value of the antioxidant was low and had no effect on the system. Of course, the method of adding antioxidant can not fundamentally solve the problem of discoloration, but in a certain range, it can effectively prevent blackening, loss of luster and return to coarse, maintain product gloss and improve storage stability. In the process of production and storage, contact with oxygen should be isolated as far as possible to avoid the oxidation of aluminum paste In general, preventing oxygen aging and harmful polymerization can improve the quality of aluminium paste to a certain extent