PlainPatent

CPC technology class · C23

C23D - Enamelling OF

Enamelling of, or applying a vitreous layer to, metals. 94 US utility patents granted 2015–2025, with the leading assignees and year-by-year filing trajectory.

94
US patents granted
C23
Parent CPC class
8
Active assignees
+110%
5-yr velocity

The verdict

Enamelling OF ranks #622 of 670 CPC technology areas - 94 US patents granted since 2015, with filing up 110% over five years.

#622
of 670 CPC technology areas
94
US patents granted, 2015–2025
Lg
leading assignee (9)
+110%
filing velocity, last 5 yrs
Top assignee: LG Electronics Inc. (9 patents)

CPC subclass C23D - ENAMELLING OF, OR APPLYING A VITREOUS LAYER TO, METALS - covers 94 US utility patents granted between 2015 and 2025 according to USPTO PatentsView records, within the broader CPC class C23 (COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTAT). See our CPC classification guide for how the system works.

The competitive landscape in C23D is shaped by 8 distinct companies actively filing in this space. LG Electronics Inc. leads with 9 patents, followed by ZYP Coatings, Inc. at 3 grants and EPG (engineered Nanoproducts Germany) Ag at 2.

Filing activity in C23D is up 110% over the past five years versus 2015-2019, a sharp acceleration suggesting an emerging or fast-moving technology area. All counts come directly from USPTO PatentsView and reflect US granted utility patents only.

Is C23D innovation accelerating?

US utility-patent grants per year in C23D, 2015–2025 - recent five years are up 110% versus 2015–2019.

051015 20152016201720182019202020212022202320242025 11

Who leads C23D?

The 12 most active assignees in ENAMELLING OF, OR APPLYING A VITREOUS LAYER TO, METALS - wider bars mean more grants

patents

What this shows Lg is the most active filer in C23D, holding 9 of the 94 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 C23D
Rank Company Patents in C23D
#1 Suncoke Technology AND Development Llc 6
#2 ZYP Coatings, Inc. 3
#3 EPG (engineered Nanoproducts Germany) Ag 2
#4 BHI Co., Ltd. 2
#5 Nihon Parkerizing Co., Ltd. 1
#6 Miir Holdings, Llc 1
#7 Miclau-s.r.i. Inc. 1
#8 Ehime Prefecture 1

About This Class

CPC subclass C23D belongs to class C23.

94 patents were granted in this class between 2015 and 2025.

8 companies actively patent in this space.

Classification System

Cooperative Patent Classification (CPC) is a hierarchical patent classification system used by the USPTO and EPO.

← All Technology Classes Technology Rankings →

Footprint here vs. claim strategy

Each dot is a leading C23D 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 8 C23D assignees by class footprint. Bubble size = patents in C23D. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Top 8 C23D assignees by class footprint. Bubble size = patents in C23D. Source: USPTO PatentsView (claim depth is company-wide across all classes). Scatter plot of 8 data points (bubble-sized by third dimension). 05101520 02468 Patents in C23D Avg claims / patent (company-wide) Suncoke Technology An…Zyp CoatingsEpg (Engineered Nanop…BhiNihon ParkerizingMiir HoldingsMiclau-s R IEhime Prefecture
Top 8 C23D assignees by class footprint. Bubble size = patents in C23D. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Frequently Asked Questions

What is CPC class C23D?
CPC subclass C23D covers ENAMELLING OF, OR APPLYING A VITREOUS LAYER TO, METALS. It belongs to CPC class C23 (COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTAT), with 94 US utility patents granted since 2015.
How many patents have been filed in C23D?
94 US utility patents were granted in CPC subclass C23D between 2015 and 2025, based on USPTO PatentsView data.
Which company holds the most patents in C23D?
LG Electronics Inc. leads C23D with 9 patents, making it the most active assignee in this technology area.
How is patent data for C23D collected?
Patent data comes from USPTO PatentsView, a public research dataset maintained by the United States Patent and Trademark Office. It covers all US granted utility patents and assigns CPC codes based on the technology described in each patent.
What is the difference between CPC class and subclass?
A CPC class (e.g., C23) is a broad technology category. Subclasses like C23D provide finer granularity within that category. PlainPatent organizes data at the subclass level (4-character codes) for the most useful view of technology domains.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from USPTO PatentsView - official U.S. government patent data. See our methodology for computation details. Retrieved and formatted by PlainPatent Editorial

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.