Famous Inventions: Scotchgard

When you get an idea for an invention, it is easy to consider the challenges, risks, and possible setbacks you may encounter and become discouraged. However, there are many stories of famous inventions that involved all of those setbacks and challenges—inventions that people can’t imagine living without today. While many products are the result of coming up with an idea first, and then developing it, many other projects are inspired by moments in everyday life. Some of the most famous inventions have even been invented entirely by accident. The invention of Scotchgard is the story of a product that was discovered entirely by accident, but which still required several years, and a great deal of patience, to develop.

Patsy Sherman, a recent graduate of Gustavus Adolphus College and Samuel Smith, were working for the 3M Company in 1952, attempting to develop a new kind of rubber for jet aircraft fuel lines. One day, a lab assistant spilled some freshly-made synthetic latex that Sherman had mixed onto his shoe. The canvas tennis shoe didn’t appear changed, but after repeated attempts Sherman and Smith were unable to dissolve the substance with a solvent or scrub it off. Instead of focusing on removing it, the two concentrated on understanding the principles of what caused the substance to behave in that way. The area resisted soiling and repelled water. The two recognized the commercial potential of its application and worked on developing it for four years; the product was first sold in 1956. It would be another several years until Sherman and Smith received their first patent for the chemical, Scotchgard, however. The patent, # 3574791 was approved in 1973. During the products development in the 1950s, Sherman was required to wait for performance results outside of the textile mill during testing, due to a rule at that time that women were not allowed in the mill. Sherman was one of few female chemists working at the time, and a rarity in the corporate environment. She was asked to speak on Minnesota Public Radio in 1969 to appeal to the housewives in the radio audience, discussing the merits of her product.

Scotchgard was the first of 13 patents that Sherman and Smith would go on to hold together in fluorochemical polymers and polymerization processes. In 1999, the United States Environmental Protection Agency (EPA) began an investigation into the class of chemicals used in Scotchgard, after receiving information about the global distribution and toxicity of the key ingredient the product used. Under pressure from the EPA 3M announced the phase-out of production of products with the chemicals PFOA and PFOS in May of 2000. It took three years for the company to develop another substance that could be used in its place; in June 2003, 3M was able to replace the PFOS with a butane-based acid, which had a much shorter half-life in people than the original PFOS (slightly over one month, as opposed to 5.4 years), and the production of Scotchgard was allowed to recommence. Sherman and Smith were inducted into the National Inventors Hall of Fame in 2001, and Sherman was also inducted into the Minnesota Science & Technology Hall of Fame in 2011; she also received the Joseph M. Biedenbach Distinguished Service Award in 1991 from the American Society for Engineering Education. Smith accumulated 30 United States Patents in total, and retired from 3M in 1998.

The invention of Scotchgard illustrates that the process of developing a new invention requires a great deal of patience. A new product can be discovered by accident, and many are, but the true test of an invention is the ability to gradually develop the idea into a marketable product. There are many trials in front of any inventor, and not all inventions will be successful, but the story of Patsy Sherman, Samuel Smith, and their invention of Scotchgard illustrate that anyone can be an inventor.