Patent amortization; patent defense On January 2, 2016, David Corporation purchased a patent for $500,000. The remaining legal life is 12 years, but the company estimated that the patent will be useful only for eight years. In January 2018, the company incurred legal fees of $45,000 in successfully defending a patent infringement suit. The successful defense did not change the company’s estimate of useful life. Required: Prepare journal entries related to the patent for 2016, 2017, and 2018.