11.15.05
Patent No. US 6,736,857 B2: Research-ers for 3M Innovative Properties Co., St. Paul, MN, earned a patent for a carpet cleaner imparting soil and stain resistance, which comprises water, a stainblocker from copolymers of methacrylic acid and butyl acrylate, a silsesquioxane and a surfactant. It requires vacuum removal.