PlainPatent

CPC technology class · C04

C04B - Lime

Lime, magnesia; slag; cements; compositions thereof, e.g. mortars, concrete or like building materials; artificial stone ; ceramics ; refractories; treatment of natural stone. 14,853 US utility patents granted 2015–2025, with the leading assignees and year-by-year grant trajectory.

14,853
US patents granted
#1/1
in C04
100.0%
C04 class share
+3%
5-yr velocity

The verdict

According to USPTO PatentsView, Lime ranks #123 of 670 CPC technology areas - 14,853 US patents granted since 2015, with recorded grant volume up 3% over five years.

#123
of 670 CPC technology areas
14,853
US patents granted, 2015–2025
Ngk Insulators
leading assignee (451)
+3%
grant velocity, last 5 yrs

How C04B's grant cadence moved

Between 2020–2024, C04B recorded 6,493 grants versus 6,312 in 2015–2019 (+3% equal-window velocity). Across complete years, output peaked in 2020 at 1,392 grants and bottomed in 2015 at 1,199 (+16% peak-over-trough). Lead assignee NGK Insulators, Ltd. holds 3.0% of the class ; the top three share 7.7%.

Leaderboard read

C04B concentration, lead at 3.0%

NGK Insulators, Ltd. leads this historical grant record at 3.0% of C04B - foreign corporation assignees hold 56% of class grants (4,615 of 8,182). Figures describe granted US utility patents in this CPC subclass, not current investment or legal strength.

Leader's share
3.0%

451 of 14,853 grants

Top three share
7.7%

of the class's recorded grants

Lead over #2
34

more grants than Halliburton Energy Services, Inc.

Rising assignees active in C04B

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. #1 RTX Corporation 662x 0 → 662 company-wide · 104 in C04B
  2. #2 Proterial, Ltd. 139x 0 → 139 company-wide · 8 in C04B
  3. #3 JX Metals Corporation 41x 0 → 41 company-wide · 5 in C04B
  4. #4 Niterra Co., Ltd. 38x 0 → 38 company-wide · 10 in C04B
  5. #5 Gold Bond Building Products, LLC 25x 1 → 25 company-wide · 17 in C04B

C04B grants by year, peak 2020 (1,392)

US utility-patent grants per year in C04B, 2015–2025 - recent five years are up 3% versus 2015–2019.

9001,0001,1001,2001,3001,4001,500 20152016201720182019202020212022202320242025 965

Who leads C04B?

The 12 most active assignees in Lime, MAGNESIA; SLAG; CEMENTS; Compositions Thereof, e.g. Mortars, Concrete OR Like Building MATERIALS; Artificial Stone ; Ceramics ; REFRACTORIES; Treatment OF Natural Stone - wider bars mean more grants

patents

What this shows Ngk Insulators is the most active filer in C04B, holding 451 of the 14,853 patents in this class. Concentration at the top signals how contestable this technology area is for new entrants.

Source USPTO PatentsView, granted utility patents As of 2015–2025 grant years
View data table
Top patent holders in CPC subclass C04B
Rank Company Patents in C04B
#1 NGK Insulators, Ltd. 451
#2 Halliburton Energy Services, Inc. 417
#3 Saudi Arabian OIL Company 271
#4 Corning Incorporated 262
#5 TDK Corporation 164
#6 Rolls-Royce Corporation 135
#7 United States Gypsum Company 132
#8 Mitsubishi Materials Corporation 129
#9 Sika Technology AG 121
#10 Raytheon Technologies Corporation 106
#11 RTX Corporation 104
#12 Taiyo Yuden Co., Ltd. 95
#13 Saint-gobain Ceramics & Plastics, Inc. 92
#14 King Fahd University OF Petroleum AND Minerals 90
#15 Goodrich Corporation 87
#16 Saint-gobain Centre DE Recherches ET D'etudes Europeen 75
#17 Schlumberger Technology Corporation 72
#18 Skyworks Solutions, Inc. 68
#19 Rolls-Royce High Temperature Composites, Inc. 65
#20 Sumitomo Electric Hardmetal Corp. 63

Footprint here vs. claim strategy

Each dot is a leading C04B 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 C04B assignees by class footprint. Bubble size = patents in C04B. Source: USPTO PatentsView (claim depth is company-wide across all classes). Scatter plot of 14 data points (bubble-sized by third dimension). 5101520 0100200300400500 Patents in C04B Avg claims / patent (company-wide) Ngk InsulatorsHalliburton Energy…Saudi Arabian OilCorning IncorporatedTdkRolls-royceUnited States GypsumMitsubishi MaterialsSika TechnologyRaytheonRtxTaiyo YudenSaint-gobain Ceramics…King Fahd University…
Top 14 C04B assignees by class footprint. Bubble size = patents in C04B. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Classes near C04B's 14,853-grant footprint

Nationwide nearest neighbors for C04B (#123 of 670 by volume ; lead share 3.0%) - not the C04 parent-class siblings above.

Nearest by grant volume

G01M 14,845 F16B 14,787 H01H 14,753 H01B 14,745

Nearest by lead-assignee share

C08K 3.0% A01N 3.0% C25D 3.1% C25C 3.1%

Questions about C04B

Which company holds the most patents in C04B?
NGK Insulators, Ltd. leads C04B with 451 patents (3.0% of the subclass). By PatentsView assignee type, foreign corporations account for 56% of class grants.
Which C04B assignees grew fastest recently?
Among assignees with ≥5 grants in C04B, RTX Corporation shows the highest company-wide grant multiple (662x: 0 grants in 2019–2021 → 662 in 2022–2024) while holding 104 patents in this subclass. Growth is company-wide, not class-only.

What to do with this data

C04B in context - here's where to go next.

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

Methodology - C04B figures are USPTO PatentsView granted-utility totals for this subclass (14,853 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.