What's the noun for patentholders? Here's the word you're looking for.
patent
A declaration issued by a government agency declaring someone the inventor of a new invention and having the privilege of stopping others from making, using or selling the claimed invention; a letter patent.
A specific grant of ownership of a piece of property; a land patent.
“A reluctant patentor, and in this instance still working through some problems in his method, Nasmyth abandoned the project after hearing Bessemer at the meeting.”