E.I. du Pont de Nemours and Co. had a record-breaking year for patent generation, with 910 new U.S. patents granted in 2011, the Delaware-based company announced Wednesday. The number of new patents issued represents an increase of 8 percent from 2010 and breaks the previous record set in 1966 when the company was awarded 780 U.S. patents. DuPont patent filings in 2011 mirrored the company's research and development investment, it said. Last month, the Patent Board ranked DuPont as the No. 1 innovator in the chemical industry for the fifth consecutive year in its Patent Scorecard. DuPont is the parent company of Pioneer Hi-Bred International Inc. in Johnston.