Within this dataset of 4,165 records, filing is moderately concentrated: the leading assignee holds 291 records, and the top five combined account for 983 records, or 23.6% of all records in scope. That leaves more than three-quarters of the field spread across a long tail of smaller filers, so no single company controls the space outright. Anyone assessing freedom-to-operate should still check the leader's core claims first, since its portfolio is more than double the size of the fifth-ranked filer's.

Filings peaked at 147 in 2020, then declined from 141 in 2021 to 94 in 2024, a 33% drop over that three-year span. That is a genuine slowdown based on complete-year data, not an artefact of reporting delay. Figures for 2025 and 2026 are still partial because publication lags filing by roughly 18 months, so they should not be read as evidence of a further decline.

The dominant class is C09K, materials for miscellaneous applications, appearing in 38.7% of the 4,165 records in scope. Corrosion and metal removal chemistry (C23F) follows at 14.6%, with food chemistry (A23L, 13.7%) and medicinal preparations (A61K, 11.7%) also present at meaningful levels. Because a single record can carry several IPC classes, these percentages sum to more than 100% of the record total and should be read individually, not added together.

US5772912A, filed by NASA's Administrator and issued in 1998, claims an aqueous, non-electrolytic, biodegradable, single-phase liquid anti-icing or deicing composition built on a non-toxic freezing point depressant drawn from a defined list of monohydric and polyhydric alcohols and their ether derivatives, applied to aircraft and related infrastructure surfaces. It is a formulation-and-use patent rather than a platform patent, so it constrains compositions that fall within its specific alcohol and mixture limitations rather than the entire anti-icing fluid category. A new formulation using a freezing point depressant outside that defined alcohol list, or combined with claim elements this patent does not cover, would sit outside its scope, though a formal claim chart is the only reliable way to confirm that for a specific composition.

The IPC composition shows heavy claim density in core materials chemistry (C09K) and corrosion inhibition (C23F), but comparatively lighter coverage in areas like residue rehydration, holdover-time indicator chemistry, and biocide-freezing depressant co-formulations. These adjacent branches sit next to the crowded core claims without being as densely occupied themselves. That pattern suggests room for narrower, application-specific claims in those branches, though any specific opportunity still needs a dedicated freedom-to-operate search before committing R&D spend.