US Patent 10,124,142: Nitric Oxide Generation From NO2 Using Water-Coated Antioxidant Surface Media

United States Patent 10,124,142 claims a method that generates nitric oxide (NO) from a gas stream containing nitrogen dioxide (NO2) by passing the gas through a surface-active material that is coated or saturated with an aqueous solution of an antioxidant, where the antioxidant is ascorbic acid, alpha tocopherol, or gamma tocopherol. The method is implemented in a receptacle with an inlet, outlet, and surface-active material positioned so the gas flows through the coated surface media. Claims also narrow to specific implementations: water-retaining substrates, silica gel (35 to 70 mesh), cartridges, ambient temperature, and specific ascorbic-acid preparation conditions (solution concentration; soaking and drying steps; drying with gas).

What is the claimed technical mechanism?

The independent claim requires a chain of process elements:

Gas feed: a gas flow including nitrogen dioxide is provided to a receptacle.
Receptacle architecture: the receptacle has an inlet, an outlet, and a surface-active material.
Surface chemistry: the surface-active material is coated with an aqueous antioxidant solution.
Conversion step: nitrogen dioxide is converted to nitric oxide as the gas communicates through the surface-active material.
Antioxidant scope: the antioxidant includes ascorbic acid, alpha tocopherol, or gamma tocopherol.

Claim 1 is therefore a functional conversion claim: it does not require a particular device brand or nozzle geometry; it ties patentability to the combination of (i) NO2-containing gas, (ii) flow through coated surface media, and (iii) conversion enabled by an antioxidant in water on the surface media.

What are the claim-by-claim coverage boundaries?

Independent claim

Claim 1 sets the baseline scope:

Method of delivering nitric oxide to a human.
Converting nitrogen dioxide to nitric oxide.
Using a receptacle with inlet/outlet and a surface-active material.
Surface-active material is coated with an aqueous solution of an antioxidant.
Antioxidant is limited to ascorbic acid, alpha tocopherol, or gamma tocopherol.
Gas flow communicates to the outlet through the surface-active material such that NO2 converts to NO.

Key practical boundary: infringement requires that the NO2 conversion occurs by gas flow through the antioxidant-coated surface-active material rather than by a bulk chemical reactor or different catalyst system.

Dependent claims that narrow by media structure

Claim 2: surface-active material is saturated with the aqueous antioxidant solution.
Claim 3: surface-active material comprises a substrate that retains water.
Claim 4: surface-active material comprises silica gel.
Claim 5: silica gel is 35 to 70 mesh.

These claims add structure and physical grade limitations that can carve out competitors who use different media classes (e.g., ion exchange resins, activated carbon with different wetting strategy, membrane catalysts, or non-silica porous carriers).

Dependent claims that narrow by device form factor

Claim 6: receptacle comprises a cartridge.

This targets modular consumable formats. Systems that integrate the media in a non-cartridge architecture may avoid this particular dependent claim, while still risking claim 1 depending on whether “receptacle including an inlet, outlet” is satisfied.

Dependent claims that narrow by temperature

Claim 8: receptacle is at ambient temperature.

This limits implementations where conversion requires heating, elevated temperature operation, or thermal cycling.

Dependent claims that narrow by antioxidant identity

Claim 7: antioxidant comprises ascorbic acid.
Claim 15: antioxidant comprises alpha tocopherol or gamma tocopherol.

This split means there are at least two narrower commercial pathways:

Ascorbic acid wetted media systems
Tocopherol wetted media systems
Both remain under claim 1, but the dependent claims define specific antioxidant embodiments.

What do the dependent claims say about the antioxidant preparation process (ascorbic acid focus)?

Claims 9 through 14 tightly define preparation and concentration of ascorbic-acid aqueous solution and drying steps:

Claim 9: surface-active material prepared using a solution of ascorbic acid in water.
Claim 10: prepared using 20% solution of ascorbic acid in water.
Claim 11: prepared using 25% solution of ascorbic acid in water.
Claim 12: prepared using 30% solution of ascorbic acid in water.
Claim 13: prepared by soaking surface-active material in ascorbic-acid solution and air drying before inserting into receptacle.
Claim 14: prepared by soaking and drying with a gas before inserting into receptacle.

These process claims affect freedom to operate in a very direct way. Competitors using different concentrations (outside 20%, 25%, 30%), different drying conditions (vacuum drying, oven drying at controlled temperature, lyophilization), or different coating methods (spray deposition, immobilization, in-situ impregnation under different humidity control) may avoid those dependent claims while still potentially falling into claim 1 if they still use an antioxidant-coated surface-active material with aqueous coating and conversion.

What are the device-internal flow path and packing limitations?

Claim 16: receptacle includes screen and glass wool adjacent to both inlet and outlet.
Claim 17: screen and glass wool are soaked in the aqueous solution of antioxidant before being inserted into the receptacle.

These claims increase specificity. A design that uses only the main silica/surface media without additional screen/glass-wool filtration layers may avoid claim 16/17 while still intersecting claim 1 if the surface-active material with aqueous antioxidant coating performs the conversion.

What is the practical claim scope vs. design-around landscape?

Below is a structured view of what would likely keep a competitor inside claim 1 versus what could plausibly move them outside the narrower dependent claims.

Elements that generally must be present to stay within Claim 1

A NO2-containing gas feed.
A receptacle with inlet/outlet.
A surface-active material through which gas flows.
The surface-active material has an aqueous antioxidant solution coating/saturation.
Antioxidant is limited to ascorbic acid, alpha tocopherol, or gamma tocopherol.
Gas flow results in NO2-to-NO conversion.

Where dependent claims create additional carve-outs

Silica gel only (claims 4-5) and mesh size (claim 5).
Water-retaining substrate (claim 3).
Cartridge format (claim 6).
Ambient temperature operation (claim 8).
Specific ascorbic acid concentration and drying (claims 10-14).
Screen and glass wool soaked (claims 16-17).

A product using a different antioxidant (not on the enumerated list), non-aqueous coating, non-surface-active catalyst form, or no NO2 conversion by the coated media would be the most material design-around.

What does this imply for patent landscape positioning and competitive risk?

1) The claim set is “composition-in-process” constrained

The antioxidant is enumerated, and it is required to be in aqueous solution on the surface-active material. That combination narrows chemical freedom but can still cover multiple device designs because claim 1 is broad on:

receptacle form factor (only requires inlet/outlet and surface-active material),
media class (only made specific in dependents like silica gel and water-retaining substrate),
and preparation method (only specified in dependents 9-14).

2) Competitive risk is concentrated around NO2-to-NO conversion in wet antioxidant-coated porous media

If competitors pursue plasma/thermal conversion, membrane-assisted conversion, electrochemical conversion, or catalytic conversion using a different chemical system (e.g., metal catalysts or solid-state reduction chemistry), they can avoid the claim’s required antioxidant-coated aqueous surface-active mechanism.

3) The ascorbic-acid concentrations and drying steps matter for infringement strategy

Even when competitors use the same antioxidant class (ascorbic acid), different concentrations or drying methods can shift exposure:

Claim 1 can still read onto them if the antioxidant is aqueous-coated and functions in conversion.
Claims 10-14 are stronger hooks if their processes match the defined 20%, 25%, 30% and drying approaches.

4) Silica gel mesh provides a specific fallback constraint

Silica gel and mesh size can be a litigation focal point because it allows a clean comparison to competitor media specs:

If competitors use silica gel outside the 35 to 70 mesh range, they may avoid claim 5 while staying exposed to claims 1 and 4 depending on whether conversion still occurs via antioxidant aqueous coating on silica.

Scope summary table (what is claimed vs. what is not explicitly claimed)

Claim element	Scope in US 10,124,142	Design impact
Conversion target	NO2 to NO	Must be NO2-containing feed and NO generation by the claimed mechanism
Antioxidant candidates	Ascorbic acid; alpha tocopherol; gamma tocopherol	Non-enumerated antioxidants are outside the claim set
Antioxidant presentation	Aqueous solution coating on surface-active material	Non-aqueous impregnation is a key carve-out
Media architecture	Surface-active material in receptacle between inlet/outlet	Competitors using separate reaction chambers face mismatch
Media examples	Water-retaining substrate; silica gel; silica gel 35-70 mesh	Narrow dependent coverage around silica mesh
Device format	Cartridge; screen and glass wool adjacent to inlet/outlet (in dependents)	Dependent hooks on packing and modular format
Operation conditions	Ambient temperature (dependent)	Heating-based designs can avoid dependent claim 8
Ascorbic preparation	20%, 25%, 30%; soak and air dry or gas dry	Process divergence can avoid dependent claims 10-14

Key Takeaways

US 10,124,142 is centered on NO2-to-NO conversion produced by gas flow through antioxidant-coated porous surface media where the antioxidant is limited to ascorbic acid, alpha tocopherol, or gamma tocopherol in an aqueous solution.
Claim 1 is the main breadth anchor; it ties infringement to the functional conversion achieved by the aqueous antioxidant-coated surface-active material.
Dependent claims add enforceable narrow hooks: silica gel (35 to 70 mesh), cartridge format, ambient temperature, specific ascorbic acid solution concentrations (20-30%), soak-and-dry steps, and screen/glass wool soaked configurations.
The most robust design-arounds are those that change at least one of the required claim pillars: antioxidant identity, aqueous coating, surface-active media mechanism, or NO2-to-NO conversion pathway.

FAQs

Is the core novelty in the antioxidant chemistry or the device layout?
The claims prioritize the method where NO2 converts to NO during gas flow through an aqueous-antioxidant-coated surface-active material. Dependent claims narrow device layout and packing (cartridge; screen/glass wool).
Does the patent require silica gel?
No. Silica gel appears in dependent claims (claims 4-5). Claim 1 only requires a surface-active material coated with aqueous antioxidant.
What antioxidant concentrations are explicitly claimed?
For ascorbic acid, the dependents explicitly cover 20%, 25%, and 30% aqueous solutions (claims 10-12).
Does the patent require ambient temperature operation?
Only in a dependent claim (claim 8). Claim 1 does not restrict temperature.
Can different media or drying methods avoid infringement?
Changing media type, antioxidant presentation, or drying method can avoid specific dependent claims (claims 4-5, 10-14, 16-17). Avoiding claim 1 requires breaking a required element such as the aqueous antioxidant-coated surface-active mechanism or using antioxidants outside the enumerated list.

References

[1] United States Patent 10,124,142 (claims as provided).

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2005277397	⤷ Start Trial
Canada	2576957	⤷ Start Trial
European Patent Office	1789119	⤷ Start Trial
European Patent Office	2724742	⤷ Start Trial
Japan	2008510675	⤷ Start Trial
Japan	2012179365	⤷ Start Trial
Japan	5421530	⤷ Start Trial
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Details for Patent: 10,124,142

Summary for Patent: 10,124,142