The filing trend in this dataset peaked at 74 records in 2019 and has declined toward single digits by the most recent partial year, with the 2022 midpoint of 44 confirming the drop is real rather than a data gap. This pattern is consistent with a field where core oxidation, reduction and dispersion methods were claimed early and heavily, leaving less unclaimed ground for new filings. It does not mean commercial interest in graphene oxide has stopped; it means the patent claim space for these specific methods has become more crowded, pushing new work toward adjacent applications like battery electrodes or laminates rather than the core chemistry itself.

China accounts for 346 of the 653 records in this corpus, more than the next four receiving offices combined (US at 130, EPO at 63, India at 32, WIPO at 28). Any competitive or freedom-to-operate analysis in this field needs to include Chinese-language filings, since excluding them would mean missing over half of the identified prior art. That said, the choice of where to file your own application should follow your target markets and manufacturing base, not just where prior art density is highest.

US9318231B2, held by Korea Institute of Science and Technology, claims a method of preparing reduced graphene oxide by covalently binding a halogen-substituted aromatic compound to graphene oxide and then heat-treating it at 450 degrees Celsius or less, producing reduced graphene oxide with electrical conductivity of 30,000 S/m or more. It is a process claim tied to a specific chemistry (halogen-substituted aromatic binding) and a specific low-temperature thermal treatment step, not a claim over reduced graphene oxide generally. Anyone using a different chemical route to bind functional groups before reduction, or a different heat-treatment regime, is working outside its literal claim scope, though a design-around should be checked against the full claim set, not the abstract alone.

The IPC data shows heavy representation in C08K (223 records, additives in polymers), C08L (197 records, polymer compositions) and C08J (113 records, polymer processing), indicating that integrating graphene oxide into polymer matrices is one of the most heavily claimed application areas in this corpus. That density does not mean every specific dispersion technique or matrix combination is occupied, but it does mean a broad claim to graphene oxide dispersion in polymers is unlikely to clear prior art cleanly. Narrower claims tied to a specific matrix chemistry, dispersion method, or resulting property are more likely to find open ground.

The dataset shows a fragmented ownership picture with almost no collaborative filing — only two co-assignee pairs were identified across 653 families. Recent-year momentum data shows every tracked assignee at zero or one filing in the latest year, including companies and institutes that filed more actively in earlier years, which lines up with the broader corpus-wide slowdown since 2019. This suggests the field currently has no single assignee aggressively expanding its position; a competitive monitoring strategy should track filing volume shifts over the next one to two years rather than assume the current leaders will remain static.