CPC technology class · C01

C01C - Ammonia

Ammonia; cyanogen; compounds thereof. 735 US utility patents granted 2015–2025, with the leading assignees and year-by-year grant trajectory.

Compiled by PlainPatent · May 15, 2026

735
US patents granted: #6/6
in C01: 1.7%
C01 class share: -11%
5-yr velocity

The verdict

According to USPTO PatentsView, Ammonia ranks #495 of 670 CPC technology areas - 735 US patents granted since 2015, with recorded grant volume down 11% over five years.

#495
of 670 CPC technology areas: 735
US patents granted, 2015–2025: Casale
leading assignee (39): -11%
grant velocity, last 5 yrs

How C01C's grant cadence moved

Between 2020–2024, C01C recorded 294 grants versus 332 in 2015–2019 (-11% equal-window velocity). Across complete years, output peaked in 2019 at 74 grants and bottomed in 2022 at 46 (+61% peak-over-trough). Lead assignee Casale SA holds 5.3% of the class ; the top three share 12.2%.

Leaderboard read

C01C concentration, lead at 5.3%

Casale SA leads this historical grant record at 5.3% of C01C - foreign corporation assignees hold 55% of class grants (193 of 353). Figures describe granted US utility patents in this CPC subclass, not current investment or legal strength.

Leader's share: 5.3%
Top three share: 12.2%
Lead over #2: 12

Where C01C sits inside C01

Among 6 subclasses in C01 (Inorganic Chemistry), C01C ranks #6 and holds 1.7% of the parent class's 43,500 recorded grants. Sibling chips below are the other subclasses in the same parent class, not the nationwide volume/lead-share peers further down.

C01B 20,252 C01P 12,347 C01G 6,857 C01F 2,333 C01D 976

Rising assignees active in C01C

Company-wide grant multiples (2022–2024 vs 2019–2021) among assignees with ≥5 patents in this subclass. Growth is company-wide; class patent counts are subclass-specific.

#1 Topsoe A/S 17x 0 → 17 company-wide · 5 in C01C
#2 thyssenkrupp Uhde GmbH 14x 0 → 14 company-wide · 5 in C01C
#3 Starfire Energy 6.00x 1 → 6 company-wide · 7 in C01C
#4 Natron Energy, Inc. 3.00x 8 → 24 company-wide · 8 in C01C
#5 Innovator Energy LLC. 2.29x 7 → 16 company-wide · 5 in C01C

C01C grants by year, peak 2019 (74)

US utility-patent grants per year in C01C, 2015–2025 - recent five years are down 11% versus 2015–2019.

Casale

39
Exxonmobil Research…

27
Haldor TopsØE A/S

24
Sharp Laboratories of…

21
Tokyo Institute of…

16
Stamicarbon B V

14
Thyssenkrupp…

8
Natron Energy

8
Yara International Asa

7
Jiangnan Environmental…

7
Starfire Energy

7
Kellogg Brown & Root

6

What this shows Casale is the most active filer in C01C, holding 39 of the 735 patents in this class. Concentration at the top signals how contestable this technology area is for new entrants.

View data table

Top patent holders in CPC subclass C01C
Rank	Company	Patents in C01C
#1	Casale SA	39
#2	Exxonmobil Research AND Engineering Company	27
#3	Haldor TOPSØE A/S	24
#4	Sharp Laboratories of America, Inc.	21
#5	Tokyo Institute of Technology	16
#6	Stamicarbon B.V.	14
#7	Thyssenkrupp Industrial Solutions AG	8
#8	Natron Energy, Inc.	8
#9	Yara International ASA	7
#10	Jiangnan Environmental Protection Group Inc.	7
#11	Starfire Energy	7
#12	Kellogg Brown & Root LLC	6
#13	Bechtel Hydrocarbon Technology Solutions, Inc.	6
#14	Colorado School of Mines	5
#15	thyssenkrupp Uhde GmbH	5
#16	Topsoe A/S	5
#17	Innovator Energy LLC.	5
#18	Bayotech, Inc.	5
#19	Alzchem AG	5
#20	Earth Science Laboratories, Inc.	5

Footprint here vs. claim strategy

Each dot is a leading C01C assignee, placed by how many patents it holds in this class (horizontal) against its company-wide average claims per patent (vertical) - a read on whether the class is led by broad-but-shallow filers or focused deep-claim players.

Top 14 C01C assignees by class footprint. Bubble size = patents in C01C. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Classes near C01C's 735-grant footprint

Nationwide nearest neighbors for C01C (#495 of 670 by volume ; lead share 5.3%) - not the C01 parent-class siblings above.

Nearest by grant volume

B62H 738 G21D 744 B31D 747 B27N 750

Nearest by lead-assignee share

B65C 5.3% A01M 5.3% B61K 5.3% C22C 5.3%

Questions about C01C

Which company holds the most patents in C01C?

Casale SA leads C01C with 39 patents (5.3% of the subclass). By PatentsView assignee type, foreign corporations account for 55% of class grants.

Which C01C assignees grew fastest recently?

Among assignees with ≥5 grants in C01C, Topsoe A/S shows the highest company-wide grant multiple (17x: 0 grants in 2019–2021 → 17 in 2022–2024) while holding 5 patents in this subclass. Growth is company-wide, not class-only.

How does C01C compare inside parent class C01?

Inside C01 (Inorganic Chemistry), C01C ranks #6 of 6 subclasses by grant volume and holds 1.7% of the parent class total. The largest sibling is C01B (20,252 grants).

What to do with this data

C01C in context - here's where to go next.

Casale SA leads C01C with 39 grants in this class. See full portfolio
C01C ranks #495 of 670 by grant volume among all tracked CPC technology areas. See the ranking
Inside parent class C01, the largest sibling subclass is C01B with 20,252 grants. Explore C01B

Figures reflect USPTO PatentsView grant data through 2026-05-15; pending applications not yet granted are not counted.

Methodology - C01C figures are USPTO PatentsView granted-utility totals for this subclass (735 grants in the tracked window).

Every figure on PlainPatent is rendered directly from USPTO source data, no number is typed in by an editor. This page draws directly on USPTO source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.