Aerospace Sealant Patents: Who Leads, Where the Gaps Are 2026
- One filer holds 203 of 208 ranked records, leaving almost no room to design around core polythioether chemistry without engaging that prior art directly.
- Filing activity peaked in 2017 at 29 records and has since flattened, with the 2022 midpoint showing no filings — though recent years are understated by publication lag.
- Base polymer chemistry is claimed far more densely than application methods, with C08G at 78.4% of records versus C08F at just 12.0%, marking where the open branches sit.
What this landscape covers
This landscape draws on 208 published records filed between 2015 and mid-2026 that describe aerospace and fuel tank sealant technology, spanning polythioether and polysulfide base chemistries, cure and rework methods, and fuel-resistance testing claims. Records are classified across eight IPC subclasses, from condensation polymers (C08G) and polymer compositions (C08L) down to narrower application-focused classes like coating processes and additive packages.
Receiving-office data shows the United States, Europe and Australia as the largest filing destinations, with Canada, WIPO/PCT and India also represented. The assignee ranking is short and heavily concentrated, which shapes how a newcomer should read the freedom-to-operate picture in this field.
Filing trends and technology composition
The dataset spans 208 published records filed between 2015 and mid-2026, with IPC classification showing where claim density concentrates and where it thins out.
Filing activity peaked in 2017
Filings reached their high point at 29 records in 2017 and have declined since, with the 2022 midpoint showing no filings recorded. The most recent years understate true activity because publication typically lags filing by around 18 months, so 2025-2026 figures will rise as later publications catch up.
Claim density sits heavily in base polymer chemistry
C08G (condensation polymers) appears in 78.4% of the 208 records and C08L (polymer compositions) in 63.0%, meaning most filings claim the sealant's base chemistry rather than downstream application. Coating processes (B05D, 24.0%) and additive packages (C08K, 19.7%) are comparatively thin, and addition polymers (C08F, 12.0%) are the least-claimed of the eight subclasses tracked here.
Shares are the percentage of the 208 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Aerospace Sealants and Fuel Tank Sealing with Eureka
This page is one run against one query. Ask Eureka your own question about aerospace sealants and fuel tank sealing and every answer comes back with the patent numbers behind it.
Try EurekaThe records anchoring this landscape
Phosphine-catalyzed, Michael addition-curable sulfur-containing polymer compositions
Compositions comprising Michael acceptor-terminated sulfur-containing prepolymers, thiol-terminated sulfur-containing prepolymers, and phosphine catalysts useful in aerospace sealant applications are disclosed. The compositions exhibit extended pot life, cure rapidly following activation, and provide cured sealants having improved properties useful in aerospace sealant applications.Filed by PRC DeSoto International, 2015-09-10 (US20150252233A1)
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US7879955B2 | Compositions including a polythioether | 159 |
| 2 | US8952124B2 | Bis(sulfonyl)alkanol-containing polythioethers, methods of synthesis, and compositions thereof | 139 |
| 3 | US8138273B2 | Compositions including a polythioether | 127 |
| 4 | US9540540B2 | Sulfone-containing polythioethers, compositions thereof, and methods of synthesis | 99 |
| 5 | US20170114208A1 | Reactive antioxidants, antioxidant-containing prepolymers, and compositions thereof | 94 |
| 6 | US20130345371A1 | Michael addition curing chemistries for sulfur-containing polymer compositions | 72 |
| 7 | WO2018085650A1 | Sulfur-containing poly(alkenyl) ethers, prepolymers incorporating sulfur-containing poly(alkenyl) ethers, and… | 68 |
| 8 | US8871896B2 | Michael addition curing chemistries for sulfur-containing polymer compositions | 50 |
| 9 | US20170369737A1 | Urethane/urea-containing bis(alkenyl) ethers, prepolymers prepared using urethane/urea-containing bis(alkenyl… | 49 |
| 10 | US9056949B2 | Michael addition curing chemistries for sulfur-containing polymer compositions employing bis(sulfonyl)alkanols | 49 |
Ranked by citation count within the searched corpus; older polythioether composition patents dominate the top of this table, which is expected given citation accumulation over time.
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Browse MCP servers →What the filing data actually shows
Three patterns stand out once the 208 records are broken down by class, assignee and citation weight: a concentrated base chemistry, a flattening filing curve, and a citation profile that rewards the earliest movers.
Base polymer claims dominate the field
Condensation-polymer chemistry (C08G) appears in more than three-quarters of the dataset, with C08L polymer-composition claims close behind at 63.0%. Filings clustered this heavily around base chemistry suggest the room to file a genuinely new sealant backbone is narrow.
Activity has flattened since the 2017 peak
The filing trend shows 2017 as the high point with no filings recorded at the 2022 midpoint, a pattern consistent with a mature, consolidated technology rather than an emerging one. Publication lag means the most recent years will revise upward as later filings publish.
Early polythioether patents anchor the citation graph
US7879955B2 leads citations at 159, followed closely by US8952124B2 at 139 — both polythioether composition patents. High citation counts in an older record reflect influence accumulated over time, not that the chemistry is still the most active area of filing today.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to aerospace sealants and fuel tank sealing, with the prior art for and against each one.
Who holds the claims
The ranked assignee list returned for this dataset covers 9 companies, not a top-50 or top-100 slice, and it is dominated by a single filer with a long tail behind it.
One assignee lineage dominates the ranking
The top-ranked filer accounts for 203 records against a fifth-place figure of just 2, a gap wide enough that most core polythioether and polysulfide sealant chemistry in this dataset traces back to one company lineage, PRC DeSoto International and its related BRC-DeSoto entity.
A short list with a steep drop-off
Beyond the leader, the remaining ranked assignees hold single-digit record counts each, consistent with individual inventors or smaller entities filing narrowly rather than building a portfolio.
Limited but visible co-filing activity
Ten co-assignee pairs appear in the dataset, with the strongest recurring pairing appearing four times, suggesting some individual inventors file jointly on a repeat basis rather than as one-off collaborations.
| Assignee | Recent year | YoY |
|---|---|---|
| PRC DeSoto International, Inc. | 0 | — |
| LIN RENHE | 0 | — |
| CAI JUEXIAO | 0 | — |
| KELEDJIAN RAQUEL | 0 | — |
| ITO MARFI | 0 | — |
| ANDERSON LAWRENCE G | 0 | — |
| Roller Bearing Company of America, Inc. | 0 | — |
| O2Micro International Limited | 0 | — |
Where to take this analysis
The filing data points to a concentrated core chemistry with a flattening trend and a handful of thinner branches worth a closer look before committing R&D or filing budget.
Check freedom-to-operate against the leading filer
With one assignee lineage holding the large majority of ranked records and the most-cited compositions, any new polythioether or polysulfide formulation should be checked against that filer's claim scope before development proceeds.
Run an FTO check in EurekaExplore the under-claimed branches
Vinyl-addition backbones, carbocyclic crosslinker chemistry and coating-process claims all sit well below the dominant base-chemistry classes in record share, which is where a narrower, defensible first claim is more likely to clear prior art.
Explore white space in EurekaCommon questions about aerospace sealant patents
Polythioether and polysulfide prepolymer chemistry dominates, with the C08G condensation-polymer class appearing in 78.4% of the 208 records in this dataset. The most-cited patents in the field, including US7879955B2 and US8952124B2, are polythioether composition claims, which indicates this chemistry has been both commercially adopted and heavily defended through patenting. Newer filings tend to modify this base chemistry with additive packages or alternative cure catalysts rather than replacing it outright.
The assignee ranking in this dataset is concentrated at the top, with one filer accounting for 203 of the 208 ranked records and the next-largest holding only 2. That single filer lineage, centred on PRC DeSoto International and its related BRC-DeSoto entity, holds the most-cited polythioether composition patents in the field. This concentration means most freedom-to-operate questions in base sealant chemistry trace back to that one assignee family.
Filing activity peaked at 29 records in 2017 and has declined since, with the 2022 midpoint showing no filings recorded in this dataset. That pattern reads as flat-to-declining rather than growing, though recent years are understated because publication lags filing by roughly 18 months. A genuine read on 2024-2026 activity will only be possible once later publications catch up.
The addition-polymer branch (C08F) is the thinnest of the eight IPC subclasses tracked, at 12.0% of the 208 records, and acyclic/carbocyclic compound chemistry (C07C, 16.3%) is similarly under-claimed relative to the dominant condensation-polymer and polymer-composition classes. Coating-process claims around application and cure on the airframe (B05D, 24.0%) are also comparatively open. These branches offer narrower but clearer paths to file without engaging the dense prior art around core polythioether chemistry.
US20150252233A1, filed by PRC DeSoto International in September 2015, claims sulfur-containing prepolymer compositions cured through a phosphine-catalyzed Michael addition mechanism, aimed at extending pot life while still curing rapidly once activated. It specifically covers Michael acceptor-terminated and thiol-terminated prepolymers combined with phosphine catalysts. It does not cover sealants cured by other mechanisms, such as manganese dioxide oxidative cure or moisture cure, which fall outside its claim scope.
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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.