| 摘要 |
<p>Algicidal properties are imparted to conventional color coated roofing granules by incorporating copper silicate with a heavy processing oil but not ordinarily employed in the post-treatment of such color coated roofing granules. The copper silicate employed has a particle size not exceeding about 100 mesh, preferably less than about 200 mesh, and more particularly having a particle size not exceeding about 325 mesh. The heavy processing oil, having a viscosity of about 525-950 SUS measured at 100 DEG F and present in an amount generally of about one-fourth gallon to about 11/4 gallons per ton of base granules, forms a thin film on the surface of the coated granules, with a portion of said oil generally being absorbed into the color coating and possibly into the base granules themselves. The copper silicate adheres to the surface of the granule color coating, with the finer particles thereof being adsorbed into the color coat with the processing oil.</p> |
