Accidents have been responsible for a great number of American inventions, from the implantable cardiac pacemaker to the microwave oven to silly putty. Patsy Sherman capitalized on an accident to invent one of America’s most readily recognized chemicals, Scotchgard™.
Like Gertrude Elion, Sherman found that after World War II large corporations were becoming a bit more open-minded about hiring women scientists. In 1952 she accepted an offer from 3M to work at their research labs in the newly expanding field of fluoro-chemicals.
Early in her career at 3M, as part of an effort to invent a new kind of rubber for use in jet aircraft fuel lines, Sherman had created a synthetic latex emulsion. A lab assistant accidentally dropped a glass beaker containing this latex onto the floor, where it splashed onto the assistant’s tennis shoes. Sherman and the rest of her team found that, try as they might, they could not wash the latex off of the shoe. More significantly, the water and the solvents they used to try to wash the latex off just beaded and ran off “like water off a duck’s back.”
Sherman and her colleague Sam Smith saw that the latex could be used to protect fabrics from water and other fluids. They spent three years fine-tuning the technology before patenting and releasing Scotchgard™ for the market (1955). When applied to carpet or upholstery, the chemical surrounds the fibers with an invisible, fluorochemical shield that is impervious to water, oils and most other liquids, as well as dirt. The chemical keeps fabrics clean, but also makes them more durable.
Sherman went on to further inventions at 3M; meanwhile, Scotchgard™ itself also evolved. Since 1978 it has been used to coat photographic and motion picture film: “Photogard” makes film resistant to dirt, liquids, bacteria, static, and abrasions, while keeping the film 97% translucent and 100% flexible.
Patsy Sherman continued as a demonstration-lecturer to young people on her own and others’ experiences with invention, encouraging aspiring inventors to think creatively, work with determination, and not to discount the unexpected: “Anyone can become an inventor, as long as they keep an open and inquiring mind and never overlook the possible significance of an accident or apparent failure.”
Sherman died on February 11, 2008 in Minneapolis, MN.