Section C: Chemistry; Metallurgy
~8,768,078
Applications (2013–2023)
PATSTAT worldwide
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
IPC and CPC are identically structured here. All 21 subcodes exist in both systems.
1 shared codes have differing titles between IPC and CPC.
Child Classifications
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- C04 CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES heading IPC+CPC Available in IPC and CPC
- C08 ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON heading IPC+CPC Available in IPC and CPC
- C09 DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR heading IPC+CPC Available in IPC and CPC
- C10 PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT heading IPC+CPC Available in IPC and CPC
- C11 ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES heading IPC+CPC Available in IPC and CPC
- C12 BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING heading +1 CPC IPC+CPC Available in IPC and CPC
- C22 METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS heading IPC+CPC Available in IPC and CPC
- 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 heading IPC+CPC Available in IPC and CPC
- C25 ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR heading IPC+CPC Available in IPC and CPC
Top Applicants
Top Applicants (IPC)
Section C,2013–2023, worldwide · Source: EPO PATSTAT
- CHINESE ACADEMY OF SCIENCES 57,686
- SINOPEC (CHINA PETROCHEMICAL CORPORATION) 37,754
- LG CHEM KR 30,616
- BASF (BADISCHE ANILIN & SODA FABRIK) DE 27,914
- JFE STEEL JP 26,107
- DOW GLOBAL TECHNOLOGIES US 17,330
- HARVARD UNIVERSITY US 13,743
- NIPPON STEEL CORPORATION JP 12,417
- ROCHE CH 11,347
- CORNING US 11,133
Top Applicants (CPC)
Section C,2013–2023, worldwide · Source: EPO PATSTAT
- CHINESE ACADEMY OF SCIENCES 39,328
- LG CHEM KR 34,681
- BASF (BADISCHE ANILIN & SODA FABRIK) DE 32,380
- JFE STEEL JP 26,323
- SINOPEC (CHINA PETROCHEMICAL CORPORATION) 22,347
- DOW GLOBAL TECHNOLOGIES US 20,538
- ROCHE CH 16,475
- HARVARD UNIVERSITY US 16,281
- UNIVERSITY OF CALIFORNIA US 14,980
- NIPPON STEEL CORPORATION JP 14,795
Classes in section C
-
- C01B Non-Metallic Elements; Compounds Thereof
- C01D Compounds of Alkali Metals, i.e. Lithium, Sodium, Potassium, Rubidium, Caesium, or Francium
- C01F Compounds of the Metals Beryllium, Magnesium, Aluminium, Calcium, Strontium, Barium, Radium, Thorium, or of the Rare Earth Metals
- C01G Compounds Containing Metals Not Covered by Subclasses or
C03 Glass; Mineral or Slag Wool
- C03B Manufacture or Shaping of Glass, or of Mineral or Slag Wool; Supplementary Processes in the Manufacture or Shaping of Glass, or of Mineral or Slag Wool
- C03C Chemical Composition of Glasses, Glazes or Vitreous Enamels; Surface Treatment of Glass; Surface Treatment of Fibres or Filaments Made From Glass, Minerals or Slags; Joining Glass to Glass or Other Materials
C04 Cements; Concrete; Artificial Stone; Ceramics; Refractories
C05 Fertilisers; Manufacture Thereof
- C05B Phosphatic Fertilisers
- C05C Nitrogenous Fertilisers
- C05D Inorganic Fertilisers Not Covered by Subclasses ,; Fertilisers Producing Carbon Dioxide
- C05F Organic Fertilisers Not Covered by Subclasses , , e.g. Fertilisers From Waste or Refuse
- C05G Mixtures of Fertilisers Covered Individually by Different Subclasses of Class; Mixtures of One or More Fertilisers With Additives Not Having a Specific Fertilising Activity; Fertilisers Characterised by Their Form
-
- C06B Explosive or Thermic Compositions; Manufacture Thereof; Use of Single Substances as Explosives
- C06C Detonating or Priming Devices; Fuses; Chemical Lighters; Pyrophoric Compositions
- C06D Means for Generating Smoke or Mist; Gas-Attack Compositions; Generation of Gas for Blasting or Propulsion (chemical Part)
- C06F Matches; Manufacture of Matches
-
- C07B General Methods of Organic Chemistry; Apparatus Therefor
- C07C Acyclic or Carbocyclic Compounds
- C07D Heterocyclic Compounds
- C07F Acyclic, Carbocyclic, or Heterocyclic Compounds Containing Elements Other Than Carbon, Hydrogen, Halogen, Oxygen, Nitrogen, Sulfur, Selenium or Tellurium
- C07G Compounds of Unknown Constitution
- C07H Sugars; Derivatives Thereof; Nucleosides; Nucleotides; Nucleic Acids
- C07J Steroids
-
- C08B Polysaccharides; Derivatives Thereof
- C08C Treatment or Chemical Modification of Rubbers
- C08F Macromolecular Compounds Obtained by Reactions Only Involving Carbon-To-Carbon Unsaturated Bonds
- C08G Macromolecular Compounds Obtained Otherwise Than by Reactions Only Involving Carbon-To-Carbon Unsaturated Bonds
- C08H Derivatives of Natural Macromolecular Compounds
- C08J Working-Up; General Processes of Compounding; After-Treatment Not Covered by Subclasses , , , or
- C08K Use of Inorganic or Non-Macromolecular Organic Substances as Compounding Ingredients
- C08L Compositions of Macromolecular Compounds
-
- C09B Organic Dyes or Closely-Related Compounds for Producing Dyes; Mordants; Lakes
- C09C Treatment of Inorganic Materials, Other Than Fibrous Fillers, to Enhance Their Pigmenting or Filling Properties; Preparation of Carbon Black
- C09D Coating Compositions, e.g. Paints, Varnishes or Lacquers; Filling Pastes; Chemical Paint or Ink Removers; Inks; Correcting Fluids; Woodstains; Pastes or Solids for Colouring or Printing; Use of Materials Therefor
- C09F Natural Resins; French Polish; Drying-Oils; Oil Drying Agents, i.e. Siccatives; Turpentine
- C09G Polishing Compositions; Ski Waxes
- C09H Preparation of Glue or Gelatine
- C09J Adhesives; Non-Mechanical Aspects of Adhesive Processes in General; Adhesive Processes Not Provided for Elsewhere; Use of Materials as Adhesives
- C09K Materials for Applications Not Otherwise Provided for; Applications of Materials Not Otherwise Provided for
-
- C10B Destructive Distillation of Carbonaceous Materials for Production of Gas, Coke, Tar, or Similar Materials
- C10C Working-Up Tar, Pitch, Asphalt, Bitumen; Pyroligneous Acid
- C10F Drying or Working-Up of Peat
- C10G Cracking Hydrocarbon Oils; Production of Liquid Hydrocarbon Mixtures, e.g. by Destructive Hydrogenation, Oligomerisation, Polymerisation; Recovery of Hydrocarbon Oils From Oil-Shale, Oil-Sand, or Gases; Refining Mixtures Mainly Consisting of Hydrocarbons; Reforming of Naphtha; Mineral Waxes
- C10H Production of Acetylene by Wet Methods
- C10J Production of Gases Containing Carbon Monoxide and Hydrogen From Solid Carbonaceous Materials by Partial Oxidation Processes Involving Oxygen or Steam; Carburetting Air or Other Gases
- C10K Purifying or Modifying the Chemical Composition of Combustible Gases Containing Carbon Monoxide
- C10L Fuels Not Otherwise Provided for; Natural Gas; Synthetic Natural Gas Obtained by Processes Not Covered by Subclasses or; Liquefied Petroleum Gas; Use of Additives to Fuels or Fires; Fire-Lighters
- C10M Lubricating Compositions; Use of Chemical Substances Either Alone or as Lubricating Ingredients in a Lubricating Composition
- C10N Indexing Scheme Associated With Subclass
-
- C11B Producing, e.g. by Pressing Raw Materials or by Extraction From Waste Materials, Refining or Preserving Fats, Fatty Substances, e.g. Lanolin, Fatty Oils or Waxes; Essential Oils; Perfumes
- C11C Fatty Acids Obtained From Fats, Oils or Waxes; Candles; Fats, Oils or Fatty Acids Obtained by Chemical Modification of Fats, Oils or Fatty Acids
- C11D Detergent Compositions; Use of Single Substances as Detergents; Soap or Soap-Making; Resin Soaps; Recovery of Glycerol
-
- C12C Beer; Preparation of Beer by Fermentation; Preparation of Malt for Making Beer; Preparation of Hops for Making Beer
- C12F Recovery of By-Products of Fermented Solutions; Denatured Alcohol; Preparation Thereof
- C12G Wine; Preparation Thereof; Alcoholic Beverages; Preparation of Alcoholic Beverages Not Provided for in Subclasses or
- C12H Pasteurisation, Sterilisation, Preservation, Purification, Clarification or Ageing of Alcoholic Beverages; Methods for Altering the Alcohol Content of Fermented Solutions or Alcoholic Beverages
- C12L Pitching or Depitching Machines; Cellar Tools
- C12M Apparatus for Enzymology or Microbiology
- C12N Microorganisms or Enzymes; Compositions Thereof; Propagating, Preserving, or Maintaining Microorganisms; Mutation or Genetic Engineering; Culture Media
- C12P Fermentation or Enzyme-Using Processes to Synthesise a Desired Chemical Compound or Composition or to Separate Optical Isomers From a Racemic Mixture
- C12Q Measuring or Testing Processes Involving Enzymes, Nucleic Acids or Microorganisms; Compositions or Test Papers Therefor; Processes of Preparing Such Compositions; Condition-Responsive Control in Microbiological or Enzymological Processes
- C12R Indexing Scheme Associated With Subclasses , Relating to Microorganisms
-
- C21B Manufacture of Iron or Steel
- C21C Processing of Pig-Iron, e.g. Refining, Manufacture of Wrought-Iron or Steel; Treatment in Molten State of Ferrous Alloys
- C21D Modifying the Physical Structure of Ferrous Metals; General Devices for Heat Treatment of Ferrous or Non-Ferrous Metals or Alloys; Making Metal Malleable, e.g. by Decarburisation or Tempering
C22 Metallurgy; Ferrous or Non-Ferrous Alloys; Treatment of Alloys or Non-Ferrous Metals
-
- 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
- C23D Enamelling Of, or Applying a Vitreous Layer To, Metals
- C23F Non-Mechanical Removal of Metallic Material From Surfaces; Inhibiting Corrosion of Metallic Material; Inhibiting Incrustation in General; Multi-Step Processes for Surface Treatment of Metallic Material Involving at Least One Process Provided for in Class and at Least One Process Covered by Subclass or or Class
- C23G Cleaning or Degreasing of Metallic Material by Chemical Methods Other Than Electrolysis
C25 Electrolytic or Electrophoretic Processes; Apparatus Therefor
- C25B Electrolytic or Electrophoretic Processes for the Production of Compounds or Non- Metals; Apparatus Therefor
- C25C Processes for the Electrolytic Production, Recovery or Refining of Metals; Apparatus Therefor
- C25D Processes for the Electrolytic or Electrophoretic Production of Coatings; Electroforming; Joining Workpieces by Electrolysis; Apparatus Therefor
- C25F Processes for the Electrolytic Removal of Materials From Objects; Apparatus Therefor
C99 Subject Matter Not Otherwise Provided for in This Section