Section C: Chemistry; Metallurgy
21
Classes
89
Subclasses
1,806
Main Groups
15,230
IPC
38,319
CPC
Description
Section C encompasses inventions in chemistry and metallurgy, covering the preparation, composition, and properties of chemical compounds, metals, alloys, and related processes. This broad section includes organic and inorganic chemistry, biochemistry, metallurgical treatments, and chemical engineering applications spanning industrial production, materials science, and pharmaceutical development. Section C typically excludes pure theoretical chemistry and physics, which fall under other sections, while serving as the foundational classification for chemistry-related patents across manufacturing and scientific domains.
Visualizations
Size of each class by number of subgroups
| Class | Title | Descendants |
|---|---|---|
| C01 | INORGANIC CHEMISTRY | 1,977 |
| C02 | TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE | 560 |
| C03 | GLASS; MINERAL OR SLAG WOOL | 1,486 |
| C04 | CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES | 2,079 |
| C05 | FERTILISERS; MANUFACTURE THEREOF | 148 |
| C06 | EXPLOSIVES; MATCHES | 181 |
| C07 | ORGANIC CHEMISTRY | 6,898 |
| C08 | ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON | 5,084 |
| C09 | DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR | 3,572 |
| C10 | PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT | 2,625 |
| C11 | ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES | 620 |
| C12 | BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING | 10,623 |
| C13 | SUGAR INDUSTRY | 105 |
| C14 | SKINS; HIDES; PELTS; LEATHER | 123 |
| C21 | METALLURGY OF IRON | 503 |
| C22 | METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS | 713 |
| 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 | 962 |
| C25 | ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR | 444 |
| C30 | CRYSTAL GROWTH | 228 |
| C40 | COMBINATORIAL TECHNOLOGY | 42 |
| C99 | SUBJECT MATTER NOT OTHERWISE PROVIDED FOR IN THIS SECTION | 2 |
Classification entries by hierarchy level
Child Classifications
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- C01 INORGANIC CHEMISTRY
- C02 TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C03 GLASS; MINERAL OR SLAG WOOL
- C04 CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C05 FERTILISERS; MANUFACTURE THEREOF
- C06 EXPLOSIVES; MATCHES
- C07 ORGANIC CHEMISTRY
- C08 ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C09 DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C10 PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C11 ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C12 BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C13 SUGAR INDUSTRY
- C14 SKINS; HIDES; PELTS; LEATHER
- C21 METALLURGY OF IRON
- C22 METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- 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
- C25 ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C30 CRYSTAL GROWTH
- C40 COMBINATORIAL TECHNOLOGY