PIGMENTED ALGAE-RESISTANT GRANULAR MATERIALS, METHODS OF PREPARING SAME, AND COMPOSITES SHEETS INCLUDING SAME

摘要

Long-term algicidal granules show improved color fastness over previously known granules. The granules have a ceramic coating comprising three layers, the first two of which have a copper compound such as cuprous oxide therein at relatively equal amounts. The ceramic coating further includes a third layer having pigment, a borate compound, and zinc oxide having an average particle size less than about 0.13 micrometer. In particular it has been found that the use of cuprous oxide allows conversion to black cupric oxide, which is more insoluble than cuprous oxide and black in color, allowing the algae-resistant granules to retain their original color for longer periods of time under weathering conditions. Methods of producing such ceramic-coated granular materials are also disclosed.