The assignee ranking in this dataset is led by a single company holding 347 of the 2,048 records in scope, well ahead of the fifth-ranked assignee at 77 and tenth place at 48. The top 5 assignees together account for 33.6% of all records, and the top 10 for 47.6%, so roughly half the field's activity sits with a small group of filers. Beyond that group, the ranking extends to 100 companies, most holding only a small number of families — a long tail typical of a chemistry-heavy adhesives field rather than one dominated by a duopoly.

Filings rose through the late 2010s and peaked at 91 records in 2022, then eased to 52 by 2024 — a -35% move from 2021's 80 filings. That looks like a pullback, but publication typically lags filing by around 18 months, so 2025 and 2026 figures are still incomplete and will rise as more records publish. Read 2024 as the most recent year with a reasonably complete count, and treat anything after it as provisional rather than evidence of a declining field.

Both are structural bonding chemistries covered by this dataset's search criteria, but they solve different process problems: two-component systems rely on mixing a resin and hardener at application, while reactive hot melts are applied molten and then moisture-cure to build final strength. The dataset's IPC composition shows C09J (Adhesives, 57.2% of records) and C08G (Condensation polymers, 49.9%) as the dominant classes across both approaches, meaning most patent activity sits in core chemistry rather than application-specific claims. Distinguishing the two in a novelty search matters because open-time and cure-schedule claims are typically drafted differently for each.

The clearest gap sits between the dominant chemistry classes and the thinner formulation/process classes: C08K (additive use) covers just 12.2% of records and B29C (shaping of plastics) only 5.3%, compared with 57.2% for core adhesive claims. That gap suggests more room to file a defensible, narrow claim around specific additive systems, cure-schedule acceleration, or primer-free substrate wetting than around core polyisocyanate or polyol chemistry, which is already densely claimed by the leading assignees.

US12275869B2, granted to Henkel in 2025, claims a moisture-reactive hot melt built from a specific combination of a polyisocyanate, polyether polyol, acrylic polymer, inorganic filler and a polyester diol defined by two named formula structures with specific molecular-weight and chain-length ranges. It does not block reactive hot melt adhesives generally — only formulations that fall within those specific compositional ranges and polyester diol structures. A formulation using a different polyol chemistry, or a polyester diol outside the claimed chain-length and molecular-weight windows, would sit outside its claims, though a full freedom-to-operate check should still map the claim language against any planned formulation.