The assignee ranking behind this landscape covers 100 companies drawn from 20,440 records, and it is heavily front-loaded: the leading assignee alone holds 3,768 records, and the top five combined account for 48.6% of all records in scope. By tenth place the count has already dropped to 199, so the practical concentration of risk and opportunity sits with a small number of assignees rather than being spread evenly across the ranking. Anyone doing freedom-to-operate work in this space should start with those top holders before working down the tail.

Using the cleanest complete-year comparison available, filings fell from 796 in 2021 to 373 in 2024, a 53% drop. The field's peak year was 2018 at 916 records, so the current level is well below the historical high. Figures for 2025 and 2026 are still incomplete because publication typically lags filing by around 18 months, so they should not yet be read as confirming or reversing this decline.

Measured by IPC subclass share of the 20,440 records, absorbent-article and implant-structure claims (A61F) are the largest single category at 40.1%, followed by sterilising and disinfecting claims (A61L) at 25.2%. Core polymer-chemistry classes — addition polymers, polymer processing, polymer compositions and additives — each cover a smaller share, roughly 6% to 18% of records. Since a single record can carry multiple IPC classes, these shares add up to well over 100% and should be read individually, not summed.

US20100099781A1, assigned to Evonik Superabsorber LLC, describes a process for treating superabsorbent polymer fines with caustic, mixing them with a polymerizable monomer solution, and polymerizing the mixture so the fines become indistinguishable within the new gel. That gel is then comminuted, dried and separated by particle size. Any new fines-recycling process that follows this same caustic-treatment-then-repolymerization sequence should be checked against this filing's claim scope specifically, rather than assumed clear simply because it targets a different end formulation.

The technology composition data shows article-level claims (A61F, A61L) are far more heavily claimed than composition-level and additive-level classes such as C08L and C08K, which sit at 9.1% and 6.6% of records respectively. That gap suggests more room exists at the base polymer-chemistry and additive level — specific crosslink-density and additive-modified formulations — than at the article-integration level, where claim density is already high. It is a relative signal from class coverage, not a guarantee of an open claim, so any specific formulation still needs its own search.