Sanju Sunshine, acting on behalf of the invalidation requestor Daqing Sanju Energy Purification Co., Ltd., has requested that the patentee BASF SE's patent "Method for preparing polyhydroxymethyl compounds - 200910258005.3" be declared entirely invalid. 

At the end of 2017, Sanju Sunshine was entrusted by a domestic client to file a request for the invalidation of BASF's patent ZL200910258005.3. This patent was involved in patent infringement lawsuits related to a market worth billions of yuan annually. On November 6, 2018, the Patent Reexamination Board declared all 36 claims of the patent in question invalid.