Corrosion Protection Patents: Top Companies & Filing Trends 2026
- Leadership is real but thin. the top-ranked assignee holds 653 records, yet the top 5 combined account for only 13.7% of the 16,429 records in scope — the field is broad, not cornered.
- Filing has cooled from its 2018 peak. activity peaked at 858 records in 2018 and filings fell from 478 in 2021 to 337 in 2024, a 29% three-year decline through the last complete filing year.
- Coating chemistry dominates the class mix. C23C coating and surface deposition and C09D coatings, paints and inks together touch well over half of all records, while corrosion-specific class C23F covers only 4.7%.
Filing growth compares 2021 (478 records) with 2024 (337) — 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 16,429 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This dataset tracks 16,429 published records filed against corrosion protection where the claims also touch substrate surface preparation, deposition rate control, interface adhesion or bonding, coating bath chemistry, or surface roughness. That combination narrows the field to functional coating and surface-treatment engineering rather than corrosion science in the abstract — most records sit in coating deposition and formulation classes, not in the dedicated corrosion-and-metal-removal class C23F, which covers only 4.7% of records.
Filing activity is concentrated in a handful of receiving offices, led by the United States, Europe and the WIPO PCT route, with meaningful volume also filed into Canada, India and Australia — a spread consistent with a technology embedded in automotive, industrial coatings and steel-sheet supply chains that ship globally.
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Filing trends and technology composition
Two views of the same 16,429 records: how filing volume has moved year over year, and how those records distribute across IPC subclasses.
Filings rose to a 2018 peak, then eased back
Annual filings climbed to 858 records in 2018 before easing off; by the last complete filing year, 2024, volume had fallen to 337 records, down from 478 in 2021 — a 29% decline over that span. Note that 2025 and 2026 figures are still filling in, since publication typically lags filing by around 18 months, so the most recent bars understate true activity.
Coating deposition and formulation classes dominate
C23C (coating and surface deposition) appears in 32.8% of records and C09D (coatings, paints and inks) in 26.8%, followed by B05D coating processes at 14.5% and C25D electroplating at 11.0%. Because records can carry multiple IPC classes, these shares add up to more than 100% of the 16,429 records in scope; they describe overlapping claim territory, not a partition of the field.
Shares are the percentage of the 16,429 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Corrosion Protection Patent Landscape with Eureka
This page is one run against one query. Ask Eureka your own question about corrosion protection patent landscape and every answer comes back with the patent numbers behind it.
Try EurekaA representative claim and the most-cited prior art
Steel sheet with a layered corrosion protection system
A flat steel product carries a base steel layer and a corrosion protection system under 3.5 μm thick, built from two metallic layers where the outer layer forms an alloy with the inner one, topped with a plasma polymer layer. The construction is designed to hold corrosion resistance and welding capability together rather than trading one for the other.Filed by Thyssenkrupp Steel — illustrates the multi-layer metallic-plus-polymer approach that recurs across steel-sheet corrosion claims in this dataset.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US6824281B2 | Vehicle accessory module | 1,163 |
| 2 | US5937323A | Sequencing of the recipe steps for the optimal low-k HDP-CVD processing | 942 |
| 3 | US6217658B1 | Sequencing of the recipe steps for the optimal low-dielectric constant HDP-CVD Processing | 902 |
| 4 | US6342277B1 | Sequential chemical vapor deposition | 844 |
| 5 | US20010028924A1 | Sequential chemical vapor deposition | 762 |
| 6 | US7184190B2 | Electro-optic reflective element assembly | 683 |
| 7 | US20090214825A1 | Ceramic coating comprising yttrium which is resistant to a reducing plasma | 629 |
| 8 | US20050056218A1 | Gas distribution plate fabricated from a solid yttrium oxide-comprising substrate | 623 |
| 9 | US7682657B2 | Sequential chemical vapor deposition | 601 |
| 10 | US20090315093A1 | Atomic layer deposition of metal carbide films using aluminum hydrocarbon compounds | 561 |
Citation counts favour older filings that have had more time to accumulate citations within this searched corpus — read them as a signal of influence on later filers, not as a ranking of current commercial relevance.
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Browse MCP servers →What the numbers mean for filing strategy
Three patterns stand out once the ranking, trend and class data are read together.
Leadership without lock-up
The leading assignee holds 653 records and the top 5 combined reach only 13.7% of all records in scope. That leaves the large majority of filings spread across a long tail of single- and few-filing entrants, which is a very different competitive picture from fields where a handful of firms hold most of the claim space.
Cooling from a 2018 peak
Filings peaked at 858 records in 2018 and have since declined, falling 29% from 478 records in 2021 to 337 in 2024, the last year that can be treated as complete. Several of the more active named assignees show negative year-on-year momentum in the most recent tracked year as well.
Deposition chemistry, not corrosion science, carries the claims
C23C and C09D together touch more than half of records, while the dedicated corrosion class C23F covers just 4.7%. Most protective value is being claimed through how a coating is deposited and formulated, not through corrosion-specific mechanisms as such.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to corrosion protection patent landscape, with the prior art for and against each one.
Who is filing, and where the ranking loosens
The ranked leaders span automotive OEMs, coatings majors and steel producers, but momentum among the most visible names has slowed in the most recently tracked year.
Formulators anchor the top of the ranking
Global paint, coatings and specialty-chemicals suppliers occupy several of the top ranked positions, consistent with a dataset weighted toward coating bath chemistry and formulation claims rather than end-use corrosion testing.
Materials producers claim substrate-level protection
Steel producers and industrial manufacturers file around substrate preparation and layered metallic coatings rather than pure chemistry, reflecting the representative record's focus on base-layer and metallic-alloy interfaces.
Even active filers are pulling back
Multiple assignees with meaningful historical volume show sharp year-on-year declines in the latest tracked year, including filers that dropped to zero. This is consistent with the broader 2021-to-2024 decline rather than an isolated retreat by one company.
| Assignee | Recent year | YoY |
|---|---|---|
| PPG Industries Ohio, Inc. | 3 | -63% |
| Nippon Steel Corporation | 2 | -33% |
| Chemetall GmbH | 1 | -90% |
| 3M Innovative Properties Co. | 1 | — |
| Sherwin-Williams Investment Management Company | 1 | -90% |
| Henkel KGaA | 0 | -100% |
| E.I. du Pont de Nemours & Co. | 0 | — |
| The Boeing Co. | 0 | -100% |
Where to take this analysis
The dataset points to a field with open middle ground rather than a locked leaderboard. Two directions follow naturally.
Map claim boundaries around the layered-metallic approach
The representative Thyssenkrupp-style construction combining a thin metallic bilayer with a plasma polymer topcoat recurs across steel-sheet filings. A freedom-to-operate check on this specific stack combination is worth doing before committing R&D budget to it.
Explore this claim structure in EurekaTrack the assignees losing momentum
Several previously active filers show sharp year-on-year declines. Whether that reflects portfolio consolidation, licensing-out, or a shift to trade secrecy changes what a competitive response should look like.
Run an assignee momentum search in EurekaCommon questions about the corrosion protection patent landscape
The ranking of 100 companies is led by a single assignee with 653 records, but concentration is modest overall: the top 5 assignees combined account for just 13.7% of the 16,429 records in scope. The leaders include established coatings and chemicals suppliers, automotive OEMs and steel producers, reflecting how broadly corrosion protection claims are spread across supply chains rather than held by a small clique of specialists. Because the tail is long, a freedom-to-operate review should look well past the top-ranked names.
Filing peaked at 858 records in 2018 and has since cooled, with the last fully complete year, 2024, showing 337 records versus 478 in 2021 — a 29% decline over that span. Figures for 2025 and 2026 are not yet reliable indicators of a further slowdown, since patent publication typically lags filing by roughly 18 months and those years are still filling in. Read the trend as a field past its filing peak rather than one accelerating.
C23C, covering coating and surface deposition, appears in 32.8% of the 16,429 records in scope, the single largest class. C09D, coatings paints and inks, follows at 26.8%, with B05D coating processes and C25D electroplating also carrying substantial shares. The dedicated corrosion-and-metal-removal class, C23F, covers only 4.7% of records, showing that most protective value is claimed through coating deposition and formulation rather than corrosion mechanisms specifically.
This Thyssenkrupp Steel filing claims a flat steel product with a corrosion protection system under 3.5 micrometres thick, built from two metallic layers where the outer layer alloys with the inner one, topped with a plasma polymer layer. The specific combination of a thin metallic bilayer plus a plasma polymer topcoat, engineered to preserve weldability alongside corrosion resistance, is the part most likely to constrain closely adjacent steel-sheet coating designs. Anyone designing a similar layered stack on steel substrates should map their layer thicknesses and materials against this claim specifically rather than against corrosion protection generally.
The class data shows heavy filing density in coating deposition and formulation (C23C, C09D) but comparatively thin dedicated coverage in narrower combinations, such as plasma-polymer topcoats over thin metallic bilayers, corrosion protection claimed jointly with weldability retention, and corrosion inhibition delivered through polymer additives rather than metallic layers. These are not empty categories, but they carry less claim density than the core coating classes, which is where a narrowly drafted first claim is more likely to clear prior art cleanly.
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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.