as the legal inventor of ePTFE. Following the Gore v. Garlock decision, Gore sued C. R. Bard for allegedly infringing its patent by making ePTFE vascular grafts. Bard promptly settled and agreed to exit the market. Gore next sued IMPRA, Inc., a smaller maker of ePTFE vascular grafts, in the federal district court in Arizona. IMPRA had a competing patent application for the ePTFE vascular graft. In a nearly decade-long patent/antitrust battle (1984–1993), IMPRA proved that Gore-Tex was identical to prior art disclosed in a Japanese process patent by duplicating the prior art process and through statistical analysis, and also proved that Gore had withheld the best mode for using its patent, and the main claim of Gore's product patent was declared invalid in 1990. In 1996, IMPRA was purchased by Bard and Bard was thereby able to reenter the market. After IMPRA's vascular graft patent was issued, Bard sued Gore for infringing it. Gore-Tex is used in products manufactured by many different companies. Other products have come to market exploiting similar technologies following the expiry of the main Gore-Tex patent. For his invention, Robert W. Gore was inducted into the U.S. National Inventors Hall of Fame in 2006. In 2015, Gore was ordered by the Federal Circuit Court of Appeals to pay Bard $1 billion in damages. The U.S. Supreme Court declined to review the Federal Circuit's decision. Environmental concerns PTFE is a fluoropolymer made using an emulsion polymerization process that utilizes the fluorosurfactant PFOA, a persistent environmental contaminant. In 2013, Gore eliminated the use of PFOAs in the manufacture of its weatherproof functional fabrics. Gore has published a plan for phasing out the most harmful perfluorinated compounds (PFCs) by 2025 but has defended the use of PTFE. However, research in 2020 found it is not possible to conclude that the harmful effects of PTFE and other fluoropolymers on environmental and human health are of low concern. Applications Gore-Tex materials are typically based on thermo-mechanically expanded PTFE and other fluoropolymer products. They are used in a wide variety of applications such as high-performance fabrics, medical implants, filter media, insulation for wires and cables, gaskets, and sealants. However, Gore-Tex fabric is best known for its use in protective, yet breathable, rainwear. Use in rainwear Before the introduction of Gore-Tex, the simplest sort of rainwear would consist of a two-layer sandwich, where the outer layer would typically be woven nylon or