Membrane & Separation Polymer Patents: Top Companies & Trends 2026
- Filing is fragmented at the top. the leading assignee holds 155 records and the ranked leaders' top 5 combined account for just 7.8% of the 7,314 records in scope.
- Growth has cooled from its peak. filings ran from 241 in 2021 to 185 in 2024, a 23% decline over that span, after peaking at 363 in 2017.
- Battery-adjacent classes now rival separation itself. H01M batteries and cells appear in 26.8% of records, close behind B01D separation processes at 40.4%.
Filing growth compares 2021 (241 records) with 2024 (185) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 7,314 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This landscape covers 7,314 published records filed or published between 2015 and the 2026 data cut-off, drawn from filings that combine polymer membrane or separation-polymer language with process and structural terms such as surface layer, particle morphology, mechanical strength, fibre interface and melt processing. The scope spans classic separation hardware alongside the polymer chemistries and processing routes that make the membranes work, so a single record can sit in both a filtration class and a polymer-composition class at once.
Because publication lags filing by roughly 18 months, the most recent one to two years in any trend line will always look thinner than they eventually turn out to be; treat 2025 and 2026 figures as still filling in rather than as a genuine drop-off.
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Filing trend and technology composition
Two views of the same 7,314-record dataset: how filing volume has moved year over year, and which IPC subclasses the claims actually sit in.
Filings rose to a 2017 peak, then eased back
Annual filings peaked at 363 in 2017 and had fallen to 185 by 2024, a 23% decline from the 241 filed in 2021 — the last three-year window the data can support without leaning on the still-incomplete 2025 and 2026 counts.
Separation and battery classes dominate, polymer chemistry classes trail
B01D (separation processes) touches 40.4% of records and H01M (batteries, cells and fuel cells) 26.8%, well ahead of the polymer-specific classes C08J, C08G, C08L and C08F, each in the 7-17% range — since a record can carry several classes, these shares add up to more than 100% of the 7,314 records in scope.
Shares are the percentage of the 7,314 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Membranes & Separation Polymers Patent Landscape with Eureka
This page is one run against one query. Ask Eureka your own question about membranes & separation polymers patent landscape and every answer comes back with the patent numbers behind it.
Try EurekaRepresentative filing and most-cited prior art
Perfluorinated sulfonic acid polymer membrane having porous surface layer and method for preparing the same
Provided are a perfluorinated sulfonic acid polymer membrane having a porous surface layer, which includes a surface layer and a bottom layer present at the bottom of the surface layer, wherein the surface layer is a porous layer, and the bottom layer is non-porous dense layer, and a method for preparing the same through a solvent evaporation process.Filed by Korea Institute of Science and Technology; the dual-layer surface/bottom-layer structure is the kind of claim shape worth checking before drafting anything with a porous surface over a dense support layer.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US3797494A | Bandage for the administration of drug by controlled metering through microporous materials | 1,086 |
| 2 | US20160045841A1 | New and improved system for processing various chemicals and materials | 860 |
| 3 | US5408999A | Fiber-optic probe for the measurement of fluid parameters | 763 |
| 4 | WO2015031691A1 | Massively parallel single cell analysis | 676 |
| 5 | US5599638A | Aqueous liquid feed organic fuel cell using solid polymer electrolyte membrane | 557 |
| 6 | US9727810B2 | Spatially addressable molecular barcoding | 537 |
| 7 | US20150299784A1 | Massively parallel single cell analysis | 536 |
| 8 | EP0458745A1 | Polymeric gas or air filled microballoons usable as suspensions in liquid carriers for ultrasonic echography | 526 |
| 9 | US5897955A | Materials and methods for the immobilization of bioactive species onto polymeric substrates | 524 |
| 10 | US20130157729A1 | Energy harvesting computer device in association with a communication device configured with apparatus for bo… | 501 |
Citation counts favour older filings that have had more time to accumulate citations inside this corpus; they signal influence on the field, not current commercial relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers mean for filing strategy
Four read-outs from the concentration, trend and classification data above, aimed at where to file next rather than where filings already sit.
No single company controls the field
The leading assignee holds 155 records out of 7,314, and the top 5 combined reach only 7.8% of all records in scope. That is a long tail of single- and few-filing entrants rather than a field locked up by two or three players.
Volume has eased from its 2017 peak
Filings dropped from 241 in 2021 to 185 in 2024. Combined with a 2017 peak of 363, the pattern reads as a maturing claim space rather than an emerging one — dense prior art in the core separation classes, not a technology still in its land-grab phase.
Separator chemistry is now a battery story too
More than a quarter of records carry an H01M battery/fuel-cell class alongside their separation-polymer claims. Drafting in this space increasingly means anticipating collision with battery-separator prior art, not just filtration prior art.
US and EPO carry the bulk of filing activity
The United States leads at 2,606 records, ahead of the EPO at 1,378 and WIPO/PCT filings at 987. Canada, Australia and India each sit in the low hundreds, suggesting freedom-to-operate work should prioritise US and European prior art first.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to membranes & separation polymers patent landscape, with the prior art for and against each one.
Who is filing, and where the gaps sit
The ranked leaders span industrial gas, membrane specialists, academic research offices and diversified chemical companies — no single business model dominates the list.
Industrial gas and separation specialists lead by volume
The top-ranked assignee's 155 records reflect decades of filing around industrial separation processes; this is volume built on a broad base of incremental filtration and membrane-process claims rather than a single blocking patent family.
University-industry co-filing is concentrated in a few pairs
The strongest co-assignee pairing in this dataset appears 36 times, with a second pairing at 24 and a third at 21 — these recurring pairs point to specific long-running research collaborations rather than a broad pattern of joint filing across the field.
Recent-year activity has thinned even among established filers
Several of the historically largest assignees show only one filing, or none, in the latest tracked year. Given the 18-month publication lag, this likely understates true recent activity, but it still signals that no incumbent is currently pulling away from the pack.
| Assignee | Recent year | YoY |
|---|---|---|
| UOP LLC | 1 | — |
| BASF SE | 1 | — |
| California Institute of Technology | 0 | — |
| Membrane Technology & Research Inc | 0 | — |
| Air Products & Chemicals Inc | 0 | — |
| Celgard LLC | 0 | — |
| 3M Innovative Properties Company (US) | 0 | — |
| Board of Regents, The University of Texas System | 0 | — |
Where to take this analysis
The dataset points to specific next steps depending on whether the goal is drafting, freedom-to-operate review, or scouting collaboration partners.
Check claim scope before drafting near the surface-layer structure
The porous-surface/dense-bottom-layer design pattern recurs across multiple records; run a claim-scope check against it before filing anything with a comparable dual-layer architecture.
Explore claim scope in EurekaTrack the battery-separator overlap directly
With over a quarter of records also carrying an H01M class, treat separator chemistry filings as needing clearance against battery prior art, not just filtration prior art.
Run a battery-overlap search in EurekaWatch the under-claimed branches for early movers
Fibre-interface reinforcement and melt-processed morphology control show comparatively thinner claim density; monitor these branches for new entrants before they fill in.
Set up white-space monitoring in EurekaCommon questions about this landscape
The ranking covers 100 assignees drawn from 7,314 records, with the leading company holding 155 records and the fifth-ranked holding 92. The top 5 combined account for only 7.8% of all records in scope, which means the field has no single dominant blocking player — filing is spread across industrial gas companies, membrane specialists, universities and diversified chemical firms. Anyone doing freedom-to-operate work should expect to clear a long tail of smaller filers rather than just the largest names.
Filings peaked at 363 in 2017 and had eased to 185 by 2024, a 23% decline from the 241 filed in 2021. That said, publication typically lags filing by around 18 months, so the 2025 and 2026 figures in this dataset are still incomplete and should not be read as a continuing drop. The honest read is a field that grew quickly through the mid-2010s and has since settled into a lower, steadier filing rate.
In this dataset, 26.8% of the 7,314 records carry an H01M battery/fuel-cell classification alongside separation-polymer language, against 40.4% in the core B01D separation-process class. That overlap means separator chemistry claims increasingly need clearance against battery prior art as well as traditional filtration prior art. Drafting or clearance work in this space should treat the two literatures as connected rather than separate.
Relative to the dense core classes covering separation processes and battery separators, sub-areas such as fibre-interface reinforcement in composite membranes, melt-processed separator morphology control, and particle-morphology tuning for fouling resistance carry comparatively lower claim density. These are not guaranteed to be open — they simply show less concentrated prior art in this dataset. Any first claim there should still be checked against the representative surface-layer patent family and the broader B01D/C08 classes before filing.
US20130323496A1, filed by Korea Institute of Science and Technology, claims a perfluorinated sulfonic acid polymer membrane with a porous surface layer sitting over a non-porous dense bottom layer, made through a solvent evaporation process. It matters because that dual-layer surface/bottom-layer structure is a recurring design pattern across this dataset's most active filers, so anyone planning a similarly layered membrane architecture should run a scope check against it before drafting. It is a useful representative filing for understanding how this specific claim shape has already been staked out.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.