|  | C |
SECTION C — CHEMISTRY; METALLURGY

|  | C |
Note(s) In section C, the definitions of groups of chemical elements are as follows: 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 The following notes are meant to assist in the use of this part of the classification scheme. They must not be read as modifying in any way the elaborations. Section C covers: pure chemistry, which covers inorganic compounds, organic compounds, macromolecular compounds, and their methods of preparation; applied chemistry, which covers compositions containing the above compounds, such as: glass, ceramics, fertilisers, plastics compositions, paints, products of the petroleum industry. It also covers certain compositions on account of their having particular properties rendering them suitable for certain purposes, as in the case of explosives, dyestuffs, adhesives, lubricants, and detergents; certain marginal industries, such as the manufacture of coke and of solid or gaseous fuels, the production and refining of oils, fats and waxes, the fermentation industry (e.g., brewing and wine-making), the sugar industry; certain operations or treatments, which are either purely mechanical, e.g., the mechanical treatment of leather and skins, or partly mechanical, e.g., the treatment of water or the prevention of corrosion in general; metallurgy, ferrous or non-ferrous alloys. In the case of operations, treatments, products or articles having both a chemical and a non-chemical part or aspect, the general rule is that the chemical part or aspect is covered by section C. In some of these cases, the chemical part or aspect brings with it a non-chemical one, even though purely mechanical, because this latter aspect either is essential to the operation or treatment or constitutes an important element thereof. It has seemed, in fact, more logical not to dissociate the different parts or aspects of a coherent whole. This is the case for applied chemistry and for the industries, operations and treatments mentioned in Notes (1)(c), (d) and (e). For example, furnaces peculiar to the manufacture of glass are covered by class Fulltext... Hierarchy... Expanded...C03 and not by class Fulltext... Hierarchy... Expanded...F27. There are, however, some exceptions in which the mechanical (or non-chemical) aspect carries with it the chemical aspect, for example: Certain extractive processes, in subclass Fulltext... Hierarchy... Expanded...A61K; The chemical purification of air, in subclass Fulltext... Hierarchy... Expanded...A61L; Chemical methods of fire-fighting, in subclass Fulltext... Hierarchy... Expanded...A62D; Chemical processes and apparatus, in class Fulltext... Hierarchy... Expanded...B01; Impregnation of wood, in subclass Fulltext... Hierarchy... Expanded...B27K; Chemical methods of analysis or testing, in subclass Fulltext... Hierarchy... Expanded...G01N; Photographic materials and processes, in class Fulltext... Hierarchy... Expanded...G03, and, generally, the chemical treatment of textiles and the production of cellulose or paper, in section D. In still other cases, the pure chemical aspect is covered by section C and the applied chemical aspect by another section, such as A, B or F, e.g., the use of a substance or composition for: treatment of plants or animals, covered by subclass Fulltext... Hierarchy... Expanded...A01N; foodstuffs, covered by class Fulltext... Hierarchy... Expanded...A23; ammunition or explosives, covered by class Fulltext... Hierarchy... Expanded...F42. When the chemical and mechanical aspects are so closely interlocked that a neat and simple division is not possible, or when certain mechanical processes follow as a natural or logical continuation of a chemical treatment, section C may cover, in addition to the chemical aspect, a part only of the mechanical aspect, e.g., after-treatment of artificial stone, covered by class Fulltext... Hierarchy... Expanded...C04. In this latter case, a note or a reference is usually given to make the position clear, even if sometimes the division is rather arbitrary.

METALLURGY

|  | C23 |
COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL (by metallising textiles Fulltext... Hierarchy... Expanded...D06M 11/83; decorating textiles by locally metallising Fulltext... Hierarchy... Expanded...D06Q 1/04); CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (for specific applications, see the relevant places, e.g. for manufacturing resistors Fulltext... Hierarchy... Expanded...H01C 17/06); INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL (treating metal surfaces or coating of metals by electrolysis or electrophoresis Fulltext... Hierarchy... Expanded...C25D, Fulltext... Hierarchy... Expanded...C25F) [2]

|  | C23 |
Note(s) In this class, the following expression is used with the meaning incicated: "metallic material" covers: metals; [4] alloys (attention is drawn to the Note following the title of subclass Fulltext... Hierarchy... Expanded...C22C).

|  | 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 (applying liquids or other fluent materials to surfaces in general Fulltext... Hierarchy... Expanded...B05; making metal-coated products by extrusion Fulltext... Hierarchy... Expanded...B21C 23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. Fulltext... Hierarchy... Expanded...B21D 39/00, Fulltext... Hierarchy... Expanded...B23K; working of metal by the action of a high concentration of electric current on a workpiece using an electrode Fulltext... Hierarchy... Expanded...B23H; metallising of glass Fulltext... Hierarchy... Expanded...C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone Fulltext... Hierarchy... Expanded...C04B 41/00; paints, varnishes, laquers Fulltext... Hierarchy... Expanded...C09D; enamelling of, or applying a vitreous layer to, metals Fulltext... Hierarchy... Expanded...C23D; inhibiting corrosion of metallic material or incrustation in general Fulltext... Hierarchy... Expanded...C23F; single-crystal film growth Fulltext... Hierarchy... Expanded...C30B; manufacture of semiconductor devices Fulltext... Hierarchy... Expanded...H01L; manufacture of printed circuits Fulltext... Hierarchy... Expanded...H05K) [4]

|  | C23C |
Note(s) In this subclass, an operation is considered as pretreatment or after-treatment when it is specially adapted for, but quite distinct from, the coating process concerned and constitutes an independent operation. If an operation results in the formation of a permanent sub- or upper layer, it is not considered as pretreatment or after-treatment and is classified as a multi-coating process. [4]

|  | C23C |
Subclass index
COATING USING MOLTEN COATING MATERIAL | 2/00 - 6/00
SOLID STATE DIFFUSION COATING | 8/00 - 12/00
COATING BY VACUUM EVAPORATION, SPUTTERING OR ION-IMPLANTATION | 14/00
CHEMICAL COATING | 16/00 - 20/00
CONTACT PLATING | 18/00
CHEMICAL SURFACE TREATMENT | 22/00
COATING USING INORGANIC POWDER | 24/00
OTHER COATING, MULTI-LAYER COATING | 26/00, 28/00
COMPOSITION OF METALLIC COATING MATERIAL | 30/00

|  | C23D |
ENAMELLING OF, OR APPLYING A VITREOUS LAYER TO, METALS (chemical composition of the enamels Fulltext... Hierarchy... Expanded...C03C)

|  | C23D |
Subclass index
TREATMENT PRIOR TO ENAMELLING | 1/00, 3/00
ENAMELLING | 5/00 - 11/00
AFTER-TREATMENT | 13/00, 15/00, 17/00

|  | C23F |
NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACES (working of metal by electro-erosion Fulltext... Hierarchy... Expanded...B23H; desurfacing by applying flames Fulltext... Hierarchy... Expanded...B23K 7/00; working metal by laser beam Fulltext... Hierarchy... Expanded...B23K 26/00; producing decorative effects by removing surface-material, e.g. by engraving, by etching, Fulltext... Hierarchy... Expanded...B44C 1/22; electrolytic etching or polishing Fulltext... Hierarchy... Expanded...C25F); 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 Fulltext... Hierarchy... Expanded...C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS Fulltext... Hierarchy... Expanded...C21D OR Fulltext... Hierarchy... Expanded...C22F OR CLASS Fulltext... Hierarchy... Expanded...C25 (inhibition or prevention of corrosion or incrustation during processing of hydrocarbons Fulltext... Hierarchy... Expanded...C10G 7/10, Fulltext... Hierarchy... Expanded...C10G 9/16, Fulltext... Hierarchy... Expanded...C10G 75/00) [4]

|  | C23F |
Note(s) This subclass covers inhibiting corrosion or incrustation in general, whether of or on metallic or non-metallic surfaces, subject to Note (2) below. This subclass does not cover: protective layers or coating compositions or methods of applying them; these are classified in the appropriate places, e.g. Fulltext... Hierarchy... Expanded...B05, Fulltext... Hierarchy... Expanded...B44, Fulltext... Hierarchy... Expanded...C09D, Fulltext... Hierarchy... Expanded...C10M, Fulltext... Hierarchy... Expanded...C23C; mechanical devices or constructional features of particular articles for inhibiting incrustation; these are classified in the appropriate places, e.g. in pipes or pipe fittings Fulltext... Hierarchy... Expanded...F16L 58/00; articles characterised by being made of materials selected for their properties of resistance to corrosion or incrustation; these are classified in the appropriate places, e.g. turbine blades Fulltext... Hierarchy... Expanded...F01D 5/28. Processes using enzymes or micro-organisms in order to: liberate, separate or purify a pre-existing compound or composition, or to treat textiles or clean solid surfaces of materials are further classified in subclass Fulltext... Hierarchy... Expanded...C12S. [5]

|  | C23F |
Subclass index
ETCHING, BRIGHTENING, COMPOSITIONS THEREFOR | 1/00, 3/00
OTHER REMOVING OF METALLIC MATERIAL | 4/00
INHIBITING CORROSION OR INCRUSTATION | 11/00 - 15/00
MULTI-STEP SURFACE TREATMENTS | 17/00

|  | C23G |
CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS (polishing compositions Fulltext... Hierarchy... Expanded...C09G; detergents in general Fulltext... Hierarchy... Expanded...C11D)

|  | C23G |
Note(s) Processes using enzymes or micro-organisms in order to: liberate, separate or purify a pre-existing compound or composition, or to treat textiles or clean solid surfaces of materials are further classified in subclass Fulltext... Hierarchy... Expanded...C12S. [5]