Abstract Algae-resistant roofing granules consisting of one or two coats of a fired semi-ceramic composition having a metallic copper powder which does not significantly affect the color tint strength of the pigment contained in the coatings.
Patent number: 6838152 Filing date: Jan 21, 2003 Issue date: Jan 4, 2005 Inventor: Ingo B. Joedicke Assignee: ISP Investments Inc. Primary Examiner: H. Thi Le Attorneys: William J. Davis, Imre Balogh Application number: 10/347,978