C
SECTION C — CHEMISTRY AND METALLURGY
 C

Note(s)

Definitions for Section C:

  • Alkali metals: Li, Na, K, Rb, Cs, Fr
  • Alkaline earth metals: Ca, Sr, Ba, Ra
  • Lanthanides: elements with atomic numbers 57 to 71 inclusive
  • Rare earths: Sc, Y, Lanthanides
  • Actinides: elements with atomic numbers 89 to 103 inclusive
  • Refractory metals: Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W
  • Halogens: F, Cl, Br, I, At
  • Noble gases: He, Ne, Ar, Kr, Xe, Rn
  • Platinum group: Os, Ir, Pt, Ru, Rh, Pd
  • Noble metals: Ag, Au, Platinum group
  • Light metals: alkali metals, alkaline earth metals, Be, Al, Mg
  • Heavy metals: metals other than light metals
  • Iron group: Fe, Co, Ni
  • Non-metals: H, B, C, Si, N, P, O, S, Se, Te, noble gases, halogens
  • Metals: elements other than non-metals
  • Transition elements: elements with atomic numbers 21 to 30 inclusive, 39 to 48 inclusive, 57 to 80 inclusive, 89 upwards

  
CHEMISTRY
 C01
INORGANIC CHEMISTRY (obtaining metal compounds from mixtures, e.g. ores, which are intermediate compounds in a metallurgical process for obtaining a free metal C21B, C22B; production of non-metallic elements or inorganic compounds by electrolysis or electrophoresis C25B)
 C01

Note(s)

In the absence of an indication to the contrary, a compound is classified in the last appropriate place within this class. [3]

 C02
TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (settling tanks, filtering, e.g. sand filters or screening devices, B01D)
 C03
GLASS; MINERAL AND SLAG WOOL
 C04
CEMENTS; CERAMICS, etc.; SOUND OR THERMAL INSULATING MATERIALS
 C04

Note(s)

This class does not include mechanical features provided for elsewhere, e.g. mechanical working B28, mechanical aspects of coating, e.g. applying glazes by brushing, dipping, spraying, B44, kilns F27.

 C05
FERTILISERS; MANUFACTURE THEREOF (soil-conditioning compositions or soil-stabilising compositions, e.g. mulches, C09K 17/00)
 C05

Note(s)

  1. An ingredient in a mixture of fertilisers, or a single fertiliser which contains more than one of the chemical elements on which the subdivision into sub-classes is based, is classified only in the first of the appropriate sub-classes. Thus, a nitrophosphate or an ammoniated superphosphate is classified in C05B but not in C05C, magnesium phosphate is classified in C05B but not in C05D, and calcium cyanamide in C05C but not in C05D.
  2. In this class it is desirable to add, in conformity with paragraph 80 of the Guide, after the double oblique stroke the symbols relating to complementary information concerning individual constituents of a technical subject which is already classified as such. This complementary information concerns the indication of ingredients of a mixture of different fertilisers or of fertilisers with non-fertilisers.
 C06
EXPLOSIVES; MATCHES
 C07
ORGANIC CHEMISTRY (such compounds as the oxides, sulphides, and oxysulphides of carbon, cyanogen, phosgene, hydrocyanic acid and salts thereof C01; macromolecular compounds C08; dyes C09; fermentation products C12; fermentation or enzyme-using processes to synthesise a desired chemical compound C12P; production of organic compounds by electrolysis or electrophoresis C25B 3/00)  [2]
 C07

Note(s)

  1. Anhydrides and halides of carboxylic acids are classified as the relevant acids unless otherwise indicated. Salts of a compound, unless specifically provided for, are classified as that compound, e.g. aniline hydrochloride is classified as containing carbon, hydrogen and nitrogen only (in C07C 87/52), sodium malonate is classified as malonic acid (in C07C 55/08), and a mercaptide is classified as the mercaptan. Metal chelates are dealt with in the same way. Similarly, metal alcoholates and metal phenates are classified in sub-class C07C and not in sub-class C07F— the alcoholates in C07C 31/28-C07C 31/32 and the phenates as the corresponding phenols in C07C 39/235 or C07C 39/44. Salts or adducts formed between two or more organic compounds are classified according to all compounds forming the salts or adducts. [2]
  2. In the absence of an indication to the contrary, and with the exception referred to below, a compound is classified in the last appropriate place, e.g. a compound containing an acyclic chain and a heterocyclic ring is classified only as a heterocyclic compound, and a steroid is classified only as a cyclopentanophenanthrene compound. In general, and in the absence of an indication to the contrary (such as groups C07C 59/58, C07C 59/70), the terms "acyclic" and "aliphatic" are used to describe compounds in which there is no ring; and, if a ring were present, the compound would be taken by the "last place" rule to a later group for cycloaliphatic or aromatic compounds, if such a group exists. Where a compound or an entire group of compounds exists in tautomeric forms, it is classified as though existing in the form which is classified last in the system, unless the other form is specifically mentioned earlier in the system.
  3. Albumens, proteins, alkaloids of unknown structure, glucosides of unknown structure are examples of compounds to be found unter C07G.
  4. Inventions dealing with chemical compounds and their preparation are classified in the groups for the type of compound prepared. The processes of preparation should be secondarily classified in the groups for the types of reaction employed when such groups exist. General processes for the preparation of a class of compounds falling into more than one main group are classified in the groups for the processes employed when such groups exist. The compounds prepared may be secondarily classified in the groups for the types of compounds prepared.
 C08
ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON (production of artificial threads, fibres, bristles or ribbons D01)
 C09
DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; MISCELLANEOUS COMPOSITIONS; MISCELLANEOUS APPLICATIONS OF MATERIALS
 C10
PETROLEUM, GAS AND COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
 C11
ANIMAL AND VEGETABLE OILS, FATS, FATTY SUBSTANCES AND WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES (edible oil or fat compositions A23)
 C12
BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
 C12

Note(s)

  1. In the field of sub-classes C12M-C12Q, in the absence of an indication to the contrary, an invention is classified in the last appropriate place. [3]
  2. Within this class, viruses, undifferentiated plant or animal cells, protozoa and unicellular algae are considered as micro-organisms. Also, sub-cellular parts, unless specifically provided for, are classified with the whole cell. [3]
  3. Within this class, non-obligatory classifications may be given as additional information relating to the micro-organisms used by means of the symbols of sub-class C12R[3]
 C13
SUGAR OR STARCH INDUSTRY (malt C12C)
 C14
SKINS; HIDES; PELTS; LEATHER
  
METALLURGY
 C21
METALLURGY OF IRON
 C22
METALLURGY (of iron C21); FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS (general methods or devices for heat treatment of ferrous or non-ferrous metals or alloys C21D; production of metals by electrolysis or electrophoresis C25)
 C23
WORKING OR TREATMENT OF METALS, OTHER THAN BY MECHANICAL MEANS; COVERING MATERIALS WITH METALS (decorating textiles by metallising D06Q 1/04); INHIBITING CORROSION OR INCRUSTATION IN GENERAL (treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D, C25F)  [2]
 C25
ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR (electrodialysis, electro-osmosis, separation of liquids by electricity B01D; electrolytic machining B23P; electroless, i. e. chemical, plating C23C; anodic or cathodic protection C23F; electrolytic production of single crystals C30B; electrochemical methods of analysis G01N; electrochemical measuring, indicating or recording devices G01R; electrolytic circuit elements, e.g. capacitors, H01G; electrochemical current or voltage generators H01M)  [2]
 C25

Note(s)

  1. Inventions dealing with electrolytic or electrophoretic processes and apparatus or operational features are classified (a) under the groups for the compounds or articles produced, and (b) under the groups provided for the apparatus or operational features. [2]
  2. The electrolytic or eletrophoretic purification of liquids is classified in the classes appropriate to the nature of the liquid, e.g. A01K 63/00, C02F 1/46, C25B 15/08, C25D 21/16, C25F 7/02[2]
 C30
CRYSTAL GROWTH (separation by crystallisation in general B01D 9/00)  [3]