Лако-красочные материалы — производство

Due to its chemical properties, aluminum reacts in aqueous systems, especially in alkaline or acidic media, to yield hydrogen gas. In the case of aluminum pigmented waterborne coatings, this would not only be a safety risk, but would also destroy the metallic effect [5.182].

This problem can easily be solved by using stabilized aluminum pigments. Pig­ments inhibited with phosphoorganic compounds, chrome treatments or by organic or inorganic encapsulation are commercially available. Further possibilities are pub­lished in Ref. [5.183].

The formulations should be kept as close as possible to the neutral point pH 7, and the neutralizing bases for the solvation of the resins should be as weak as possible (DMEA, NMP etc. are much more highly recommended than amines or even ammonium).

Today, a large and increasing proportion of the automotive OEM metallic basecoats in Europe and North America are already waterborne and refinish basecoats are also available in waterborne versions. Other paint applications have followed and the significant growth of waterborne systems can easily be seen in the statistics of the paint associations. Also in printing inks, the use of waterborne inks is steadily growing.