Within the 22 records in this dataset, filings are ranked across 14 companies, with the top-ranked assignee holding 6 records. The top 5 combined account for 63.6% of all records in scope, and the top 10 reach 86.4% — a field with a clear leading group but no single dominant monopoly holder. The tail beyond that is thin, with several assignees holding only one or two filings each.

Filings rose from a single record in 2017 to a peak of 6 in 2021, and the 2022 midpoint also sits at 6, meaning the second half of the tracked window has not exceeded the first. That pattern reads as flat-to-declining rather than growing. Because publication typically lags filing by around 18 months, the most recent one or two years in any such trend will always look lower than they eventually turn out to be, so this should not be read as a hard stop in activity.

The core chemistry sits in IPC class C01B, non-metallic elements and inorganic compounds, which appears in 86.4% of the 22 records in scope — the largest single category by a wide margin. Furnace details (F27D) and crystal growth (C30B) each appear in 22.7% of records, and ceramics and refractories (C04B) in 13.6%, showing that most claim activity concentrates on the core carbothermal reaction rather than on downstream ceramic finishing or furnace engineering alone.

EP4151596A1 claims a solid-state carbothermal reduction process that ties together specific reaction parameters: a carbon powder ratio of at least about 25% by weight, a substantially inert atmosphere around the crucible, and a staged heating profile reaching at least 1,500°C. It does not claim silicon carbide production or carbothermal reduction in the abstract — the protection sits on that specific combination of atmosphere, ratio and temperature staging. A process that varies any one of those elements meaningfully, or that uses a different atmosphere-generation method, sits outside the literal claim scope, though a full infringement read requires checking the dependent claims and file history.

The technology composition data shows thin coverage in furnace exhaust and wastewater treatment (C02F, 4.5% of records), mixing and stirring pre-reaction stages (B01F, 4.5%), and catalytic pathway variants (B01J, 4.5%), compared to the 86.4% concentration in core C01B chemistry. These branches sit adjacent to the dense furnace and reduction claims but are not yet heavily claimed, making them worth a closer freedom-to-operate and prior-art check before assuming they are open, rather than assuming they are automatically available.