Patent ID: 8324121

Claim:
A roof covering comprising: a roofing mat formed from a fiber material having fibers with properties suitable for forming the roofing mat, the fibers being coated with a sizing containing a film-forming polymer and a bonding material; and an asphalt-based coating material that coats the mat and binds to the fibers, the binding of the coating material to the fibers of the mat being enhanced by crosslinking via (a) the bonding material that is coated onto and bonds to fibers of the mat and (b) sulfur groups bound to the bonding material and forming cross-links with the asphalt of the coating material; wherein the tear strength of the roof covering is increased as measured by ASTM D 1922 compared to the same roof covering without the sulfur groups bound to the bonding material and cross-linked with the asphalt of the coating material.