The core classification is B32B, covering layered products and laminates, which appears in 1,307 of the 1,329 families in this dataset. Supporting classes include C08J (polymer processing), B65D (containers and packaging), C08L (polymer compositions), C23C (coating and surface deposition), B29C (plastics shaping), H01L (semiconductor devices, tied to flexible-electronics barrier applications) and C09D (coatings, paints and inks). A comprehensive search should combine B32B with at least the testing-method terms (oxygen transmission rate, water vapor transmission rate, pinhole detection) rather than relying on classification alone, since method claims are often filed under the structural class of the film itself.

Filing peaked in 2022 at 83 families and has declined since, with the most recent tracked year sitting far below that peak. Because publication lags filing by roughly 18 months, the last one to two years will always look lower than actual filing activity, so some of that drop is a reporting artifact rather than a real collapse. Even allowing for that lag, the shape of the curve — rising from 74 in 2017 to a mid-decade peak, then falling — points to a technology whose main claim-building phase has already passed rather than one still accelerating.

The dataset's assignee ranking is dominated by established packaging, materials and printing companies with long filing histories, but recent-year momentum data shows every one of the tracked leaders at flat or negative year-on-year filing. That combination — strong historical position, no current growth — means the existing ranking reflects who built the claim map, not necessarily who is most active in defending or extending it today. Co-assignee activity is also limited to just 10 pairs across the whole dataset, suggesting most positions were built through internal R&D rather than joint filing.

US20100075082A1, assigned to Dai Nippon Printing and published in 2010, claims a barrier film built around a silicon oxide barrier layer with a specific Si:O:C atomic ratio range, a defined infrared absorption peak position associated with Si—O—Si stretching vibration, and a specified film density range. Any new filing on silicon-oxide barrier layers needs to check its own composition and density figures against those ranges, since a structure falling inside all three parameters could face a blocking rejection or freedom-to-operate risk. Films using a different barrier chemistry, a different deposition method producing a distinct density/composition profile, or a materially different infrared signature sit outside the literal claim scope, though a full clearance opinion should check the full claim set and prosecution history, not the abstract alone.

The IPC composition points to C09D (coatings, paints and inks, 88 records) and H01L (semiconductor devices, 112 records) as the thinnest major subclasses relative to the dominant B32B cluster, suggesting coating-integrated barrier testing and flexible-electronics-specific barrier inspection are comparatively under-claimed. In-line, non-destructive OTR/WVTR measurement suited to roll-to-roll production lines is another area not clearly saturated based on the classification spread. None of these gaps are guaranteed to be empty — thin does not mean unclaimed — so any filing strategy targeting them should still run a focused freedom-to-operate search before committing claim language.