I basically am trying to achieve a search for patents and/or entities (that own patents) containing some specific keywords. However, I would like to exclude a few entities from the search by using the ANDNOT Boolean condition specifier. Is there a free tool or database available to achieve this purpose?
Are you looking in US patents? If so the USPTO's search is very Boolean. patft.uspto.gov/netahtml/PTO/search-adv.htm– George White ♦Jun 13, 2013 at 21:02
Searching for what entity owns which patents at this moment in time is almost impossible. The searchable databases have a field for "assignee". That is the entity, if any, that was listed in the face of the patent the day it was issued. It could have been bought and sold 10 times since then. The Recordation of assignments is incomplete and not really searchable. This is a comment rather than an answer because I'm not sure what you are trying to do.– George White ♦Jun 13, 2013 at 21:53
Try http://google.com/patents (and use Google-fu) - as George White commented however, that patent might have been brought and sold several times at your time of search