Ownership in this dataset concentrates among a small group of specialty-chemical and hygiene-product majors, including LG Chem, Procter & Gamble, and BASF, alongside long-standing SAP specialists. These firms have filed consistently across the tracked period rather than entering recently, and several show the strongest co-assignee filing pairs with individual named inventors. Recent-year momentum has slowed sharply even among these leaders, so filing rank alone does not indicate current activity level.

No — filings peaked in 2017 at 113 families and had declined to 73 by the 2022 midpoint, with the downward trend continuing toward the most recent tracked years. Because patent publication lags filing by roughly 18 months, the final one to two years in any dataset will always look artificially thin, but the multi-year direction here is a genuine plateau rather than a publication-lag artefact. This makes it a mature field where most new filings build on established absorbency mechanisms rather than introducing new ones.

Polymer processing and solutions (IPC class C08J) and sterilising/hygiene applications (A61L) are the densest classes in this dataset, each covering over a thousand records. Addition-polymer chemistry (C08F) and additive-related classes (C08K, C08L) follow behind. Anyone filing new claims around core absorption capacity, surface crosslinking or basic hygiene-article integration is filing into the most heavily claimed part of the landscape.

US20230330629A1 is a 2023 LG Chem filing for a superabsorbent polymer preparation method that introduces nanocellulose fiber during synthesis to improve gel strength, mechanical strength and absorption rate via a porous structure. It matters as a representative example of where current innovation is concentrated: not new base monomer chemistry, but fiber-reinforced processing routes that improve on established absorbency metrics like centrifuge retention capacity. It illustrates the kind of processing-route claim that is more likely to clear prior art than a claim on core absorption chemistry.

Relative to the dense core absorbency and hygiene-application classes, coverage is thinner around laminate integration of SAP layers, nanocellulose-reinforced gel strength, renewable-resource-derived polymer backbones, and catalysis-assisted crosslinking approaches. These are not empty spaces, but they carry noticeably less filing density than the core C08J and A61L classes. A freedom-to-operate search focused on these specific sub-areas is more likely to find open claim territory than a search centred on basic absorption capacity.