The algae retardant roofing granules 1 wherein {HEAD ~ said microvoids} in {TAIL ~ said second or outer layer} have an average thickness of from about 0.05 micron to about 0.5 micron 
in
The algae retardant roofing granules 1 wherein { HEAD ~ said microvoids } in { TAIL ~ said second or outer layer } have an average thickness of from about 0.05 micron to about 0.5 micron
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH