The assignee ranking in this dataset covers 17 companies, and it is heavily front-loaded: the leading assignee holds 19 of the 42 total records, while the top 5 combined account for 35 records, or 83.3% of everything in scope. By the tenth-ranked assignee the count drops to 1, and the top 10 together cover all 42 records. In practice this means a small number of filers — a mix of individual inventors, equipment specialists and an academic research cluster — define most of the active claim space, so competitive tracking should focus there rather than trying to monitor a long tail.

Filings grew substantially over the tracked period, rising from 3 in 2021 to 9 in 2024, a +200% increase, with a peak of 13 records in 2023. It would be a mistake to read the lower counts in 2025 and 2026 as a slowdown: patent publication typically lags filing by around 18 months, so the most recent one to two years in any trend chart are always undercounted until later publications catch up. The 2021-2024 window is the most reliable basis for judging momentum right now.

Two IPC subclasses tie for the largest share: C01F, covering alkaline-earth and rare-earth compounds, and C07C, covering acyclic and carbocyclic compounds, each appearing in 45.2% of the 42 records in scope. These sit ahead of C02F water and wastewater treatment (21.4%), and B02C crushing and grinding hardware (19.0%), which is closer to what many people expect a ‘crusher attachment’ patent search to return. Because a single record can carry multiple IPC classes, these shares add up to more than 100%, and the pattern shows recycled-aggregate chemistry claims now running alongside the mechanical attachment claims rather than behind them.