Retention and Drainage Aid Patents: Who Leads, White Space 2026
Retention and Drainage Aid Program Patents: Filing Trends and White Space
32.3% concentration at the top. The five leading assignees combine for 1,555 of the 4,815 records in scope — a field where a handful of specialty-chemical suppliers hold a third of the documented filings. Annual filings ran from 144 in 2017 to a peak of 150 in 2019, then eased to 12 by 2024 — a -29% move from 2021's 17 filings, the clearest complete-year comparison available. 2025 and 2026 figures are still filling in under normal publication lag and should not be read as a continued decline.
- 1CIBA SPECIALTY CHEM WATER TRATMENTS LTD9.5%
- 2AKZO NOBEL NV6.3%
- 3KEMIRA OY6.3%
- 4AKZO NOBEL CHEMICALS INTERNATIONAL BV5.8%
- 5SOLENIS TECHNOLOGIES CAYMAN LP4.4%
See the full retention and drainage aid programs analysis in Eureka
- The complete ranking, not just the top five
- Every IPC branch with its share of the corpus
- The most-cited records, and where claim space is still thin
Common questions on retention and drainage aid patents
Who holds the most patents in retention and drainage aid technology?
The ranked leader holds 459 records in this dataset, more than double the fifth-place assignee’s 211. The top five assignees combined account for 1,555 records, or 32.3% of the 4,815 records in scope, and the top ten reach exactly half the field at 2,408 records. That concentration is typical of specialty papermaking chemistry, where a small number of established suppliers have filed continuously for decades.
Is patent filing activity in this space growing or shrinking?
Filing peaked at 150 records in 2019 and has since eased; on the last fully comparable stretch, volume dropped from 17 filings in 2021 to 12 in 2024, a -29% move. Because publication lags filing by roughly 18 months, the 2025 and 2026 figures in any dataset are still incomplete and should not be read as confirming a continued decline. The honest read is a mature field with a real cooling trend through 2024, not an accelerating one.
What technology areas dominate retention and drainage aid patents?
Pulp and paper composition claims under IPC class D21H cover 77.2% of the 4,815 records in scope, making it by far the largest single category. Supporting chemistry classes — C01B inorganic compounds at 12.9%, C08F addition polymers at 9.5%, and C08L polymer compositions at 7.6% — round out the core retention-active ingredient space. Machine-side claims (D21F) and separation-process claims (B01D) each sit under 6% of records, marking them as comparatively open relative to the composition core.
Disclaimer. This analysis is based on Patsnap Eureka data drawn from a limited snapshot of global patent records and is provided for general information and reference only. Patent data carries inherent limitations — recent filings are under-counted because of publication lag, counts may be on a record or family basis, classification and applicant-name data may contain errors or duplicates, and the underlying search query defines the scope shown — so the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing here is an exhaustive prior-art, novelty, freedom-to-operate or validity search, nor does it constitute legal, financial or professional advice, and it should not be relied upon as such. Verify independently and review with qualified patent and legal professionals before acting on it.
Method: Filing trend and technology composition. Derived from a Patsnap search on Retention and Drainage Aid Programs covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish. Every share divides by all records in scope. Data: Patsnap Eureka. See the full landscape report.