U.S. Patent 2130523 is one of the patents associated with nylon, a material first produced by engineers at Dupont in the late 1930's and then continually developed there and elsewhere. Some consider it to be the first commercially successful synthetic polymer. It was first used in a toothbrush and has since expanded to use in a huge variety of applications and products.
The positives of the patent are that nylon has been useful in all kinds of applications and arguably has driven down the costs of a number of products and made them more widely available.
In terms of why it is bad, perhaps its success has prevented the development of other materials that might have been more useful or perhaps less environmentally damaging since nylon and many of its sister fibers/polymers are incredibly long-lasting and will be with us for thousands of years.