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 IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
Description
C23 encompasses processes and methods for modifying metal surfaces through coating, chemical treatment, and vapor deposition techniques. The class covers application of metallic or non-metallic coatings to metal substrates, chemical surface treatments (including passivation and conversion coatings), diffusion treatments altering surface composition, and vacuum-based deposition methods such as evaporation, sputtering, ion implantation, and chemical vapor deposition. It also includes technologies for preventing corrosion, oxidation, and incrustation of metallic materials. Related surface engineering processes such as electroplating and case hardening are typically classified in other sections of metallurgy or organic chemistry.
Filing statistics
CPC C23 recorded 311,167 patent applications worldwide between 2013 and 2023, summed across its 4 subclasses. Annual filings grew from 21,791 in 2013 to 26,911 in 2023 (+23%), peaking at 32,789 applications in 2018. The most active applicants in class C23 are APPLIED MATERIALS (10,596 applications), TOKYO ELECTRON (5,229 applications) and LAM RESEARCH CORPORATION (3,622 applications).
Source: EPO PATSTAT, worldwide filings
4 direct subcodes
Child Classifications
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- C23C COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- C23D ENAMELLING OF, OR APPLYING A VITREOUS LAYER TO, METALS
- C23F NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE (working metal by laser beams B23K26/00; desurfacing by applying flames B23K7/00; working of metal by electro-erosion B23H; producing decorative effects by removing surface material, e.g. by engraving, by etching, B44C1/22; electrolytic etching or polishing C25F); INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23G CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
Top Applicants
Top 10 applicants by patent filings, 2013–2023, worldwide · Source: EPO PATSTAT
- APPLIED MATERIALS US 10,596
- TOKYO ELECTRON JP 5,229
- LAM RESEARCH CORPORATION US 3,622
- NIPPON STEEL CORPORATION JP 3,171
- JFE STEEL JP 3,128
- ASM IP HOLDING NL 2,722
- ARCELORMITTAL LU 2,481
- TOKYO ELECTRON 2,359
- APPLIED MATERIALS 2,284
- CHINESE ACADEMY OF SCIENCES 2,110