It is a typical 3M story: an employee comes up with an idea that, through a series of accidents, then turns into a product. While trying to develop a new kind of rubber for aircraft fuel lines, someone at 3M once spilt some of the latex on a shoe and discovered it was water resistant. The company turned it into Scotchgard.
A churchgoing employee of 3M, the diversified technology company, watching the bookmarks falling out of his hymn book, secured them with a glue the company had developed that did not lose its stickiness. The result was Post-it notes.
Here is another 3M story: some employees developed a product that kept road signs clean. It worked, but wore off in a few days. Undeterred, they pondered who might need to keep something clean for a shorter time before reapplying it – and decided to use the product in miners' masks.