|  | 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 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

|  | C25 |
ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR (electrodialysis, electro-osmosis, separation of liquids by electricity Fulltext... Hierarchy... Expanded...B01D; working of metal by the action of a high concentration of electric current Fulltext... Hierarchy... Expanded...B23H; treatment of water, waste water or sewage by electrochemical methods Fulltext... Hierarchy... Expanded...C02F 1/46; surface treatment of metallic material or coating involving at least one process provided for in class Fulltext... Hierarchy... Expanded...C23 and at least one process covered by this class Fulltext... Hierarchy... Expanded...C23C 28/00, Fulltext... Hierarchy... Expanded...C23F 17/00; anodic or cathodic protection Fulltext... Hierarchy... Expanded...C23F; single-crystal growth Fulltext... Hierarchy... Expanded...C30B; metallising textiles Fulltext... Hierarchy... Expanded...D06M 11/83; decorating textiles by locally metallising Fulltext... Hierarchy... Expanded...D06Q 1/04; electrochemical methods of analysis Fulltext... Hierarchy... Expanded...G01N; electrochemical measuring, indicating or recording devices Fulltext... Hierarchy... Expanded...G01R; electrolytic circuit elements, e.g. capacitors, Fulltext... Hierarchy... Expanded...H01G; electrochemical current or voltage generators Fulltext... Hierarchy... Expanded...H01M) [4]

|  | C25 |
Note(s) Electrolytic or electrophoretic processes or apparatus or operational features are classified in the groups for the compounds or articles produced, and in the groups which cover the apparatus or operational features. [2] The electrolytic or electrophoretic purification of materials is classified according to the nature of the liquid in the relevant places, e.g. Fulltext... Hierarchy... Expanded...A01K 63/00, Fulltext... Hierarchy... Expanded...C02F 1/46, Fulltext... Hierarchy... Expanded...C25B 15/08, Fulltext... Hierarchy... Expanded...C25D 21/16, Fulltext... Hierarchy... Expanded...C25F 7/02. [2]

|  | C25 |
Class index
ELECTROLYTIC PRODUCTION |
Inorganic compounds, non-metals | C25B 1/00
Organic compounds | C25B 3/00
Non-metallic coatings | C25D 9/00
Metals | C25C 1/00, C25C 3/00, C25C 5/00
Metallic coatings | C25D 3/00, C25D 5/00, C25D 7/00
ELECTROLYTIC PRODUCTION OF COMPOUNDS OR NON-METALS WITH SIMULTANEOUS PRODUCTION OF ELECTRICITY | C25B 5/00
ELECTROPHORETIC PRODUCTION |
Compounds, non-metals | C25B 7/00
Coatings | C25D 13/00
ELECTROFORMING | C25D 1/00
ANODISING, PHOSPHATISING, CHROMATISING | C25D 11/00
COATINGS WITH EMBEDDED MATERIAL | C25D 15/00
ELECTROLYTIC CLEANING, PICKLING, OR REMOVAL OF METALLIC COATINGS | C25F 1/00, C25F 5/00
ELECTROLYTIC ETCHING OR POLISHING | C25F 3/00
CELLS, ELECTRODES, DIAPHRAGMS |
Production of compounds or non-metals | C25B 9/00, C25B 11/00, C25B 13/00, C25B 15/00
Production of metals | C25C 7/00
Production of coatings | C25D 17/00, C25D 19/00, C25D 21/00
Cleaning, pickling, surface treatment | C25F 7/00

|  | C25D |
PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING (decorating textiles by metallising Fulltext... Hierarchy... Expanded...D06Q 1/04; manufacturing printed circuits by metal deposition Fulltext... Hierarchy... Expanded...H05K 3/18); JOINING WORKPIECES BY ELECTROLYSIS; APPARATUS THEREFOR [2,6]

P:10 |  | C25D 1/00 |
Electroforming [2]

|  | C25D 1/02 |
· | Tubes; Rings; Hollow bodies [2]

|  | C25D 1/04 |
· | Wires; Strips; Foils [2]

|  | C25D 1/06 |
· | Wholly-metallic mirrors [2]

|  | C25D 1/08 |
· | Perforated or foraminous objects, e.g. sieves (Fulltext... Hierarchy... Expanded...C25D 1/10 takes precedence) [2]

|  | C25D 1/10 |
· | Moulds; Masks; Masterforms [2]

|  | C25D 1/12 |
· | by electrophoresis [2]

|  | C25D 1/14 |
· · | of inorganic material [2]

|  | C25D 1/16 |
· · · | Metals [2]

|  | C25D 1/18 |
· · | of organic material [2]

|  | C25D 1/20 |
· | Separation of the formed objects from the electrodes [2]

|  | C25D 1/22 |
· · | Separating compounds [2]

P:0 |  | C25D 2/00 |
Joining workpieces by electrolysis [6]

P:70 |  | C25D 3/00 |
Electroplating; Baths therefor [2]

|  | C25D 3/02 |
· | from solutions (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...C25D 5/24-C25D 5/32 take precedence) [2]

|  | C25D 3/04 |
· · | of chromium [2]

|  | C25D 3/06 |
· · · | from solutions of trivalent chromium [2]

|  | C25D 3/08 |
· · · | Deposition of black chromium [2]

|  | C25D 3/10 |
· · · | characterised by the organic bath constituents used [2]

|  | C25D 3/12 |
· · | of nickel or cobalt [2]

|  | C25D 3/14 |
· · · | from baths containing acetylenic or heterocyclic compounds [2]

|  | C25D 3/16 |
· · · · | Acetylenic compounds [2]

|  | C25D 3/18 |
· · · · | Heterocyclic compounds [2]

|  | C25D 3/20 |
· · | of iron [2]

|  | C25D 3/22 |
· · | of zinc [2]

|  | C25D 3/24 |
· · · | from cyanide baths [2]

|  | C25D 3/26 |
· · | of cadmium [2]

|  | C25D 3/28 |
· · · | from cyanide baths [2]

|  | C25D 3/30 |
· · | of tin [2]

|  | C25D 3/32 |
· · · | characterised by the organic bath constituents used [2]

|  | C25D 3/34 |
· · | of lead [2]

|  | C25D 3/36 |
· · · | characterised by the organic bath constituents used [2]

|  | C25D 3/38 |
· · | of copper [2]

|  | C25D 3/40 |
· · · | from cyanide baths [2]

|  | C25D 3/42 |
· · | of light metals [2]

|  | C25D 3/44 |
· · · | Aluminium [2]

|  | C25D 3/46 |
· · | of silver [2]

|  | C25D 3/48 |
· · | of gold [2]

|  | C25D 3/50 |
· · | of platinum group metals [2]

|  | C25D 3/52 |
· · · | characterised by the organic bath constituents used [2]

|  | C25D 3/54 |
· · | of metals not provided for in groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...C25D 3/04-C25D 3/50 [2]

|  | C25D 3/56 |
· · | of alloys [2]

|  | C25D 3/58 |
· · · | containing more than 50% by weight of copper [2]

|  | C25D 3/60 |
· · · | containing more than 50% by weight of tin [2]

|  | C25D 3/62 |
· · · | containing more than 50% by weight of gold [2]

|  | C25D 3/64 |
· · · | containing more than 50% by weight of silver [2]

|  | C25D 3/66 |
· | from melts [2]

P:50 |  | C25D 5/00 |
Electroplating characterised by the process; Pretreatment or after-treatment of workpieces [2]

|  | C25D 5/02 |
· | Electroplating of selected surface areas [2]

|  | C25D 5/04 |
· | Electroplating with moving electrodes [2]

|  | C25D 5/06 |
· · | Brush or pad plating [2]

|  | C25D 5/08 |
· | Electroplating with moving electrolyte, e.g. jet electroplating [2]

|  | C25D 5/10 |
· | Electroplating with more than one layer of the same or of different metals (for bearings Fulltext... Hierarchy... Expanded...C25D 7/10) [2]

|  | C25D 5/12 |
· · | at least one layer being of nickel or chromium [2]

|  | C25D 5/14 |
· · · | two or more layers being of nickel or chromium, e.g. duplex or triplex layers [2]

|  | C25D 5/16 |
· | Electroplating with layers of varying thickness [2]

|  | C25D 5/18 |
· | Electroplating using modulated, pulsed or reversing current [2]

|  | C25D 5/20 |
· | Electroplating using ultrasonics [2]

|  | C25D 5/22 |
· | Electroplating combined with mechanical treatment during the deposition [2]

|  | C25D 5/24 |
· | Electroplating of metal surfaces to which a coating cannot readily be applied (Fulltext... Hierarchy... Expanded...C25D 5/34 takes precedence) [2]

|  | C25D 5/26 |
· · | of iron or steel surfaces [2]

|  | C25D 5/28 |
· · | of surfaces of refractory metals [2]

|  | C25D 5/30 |
· · | of surfaces of light metals [2]

|  | C25D 5/32 |
· · | of surfaces of actinides [2]

|  | C25D 5/34 |
· | Pretreatment of metallic surfaces to be electroplated [2]

|  | C25D 5/36 |
· · | of iron or steel [2]

|  | C25D 5/38 |
· · | of refractory metals or nickel [2]

|  | C25D 5/40 |
· · · | Nickel; Chromium [2]

|  | C25D 5/42 |
· · | of light metals [2]

|  | C25D 5/44 |
· · · | Aluminium [2]

|  | C25D 5/46 |
· · | of actinides [2]

|  | C25D 5/48 |
· | After-treatment of electroplated surfaces [2]

|  | C25D 5/50 |
· · | by heat-treatment [2]

|  | C25D 5/52 |
· · | by brightening or burnishing [2]

|  | C25D 5/54 |
· | Electroplating of non-metallic surfaces (Fulltext... Hierarchy... Expanded...C25D 7/12 takes precedence) [2]

|  | C25D 5/56 |
· · | of plastics [2]

P:60 |  | C25D 7/00 |
Electroplating characterised by the article coated [2]

|  | C25D 7/02 |
· | Slide fasteners [2]

|  | C25D 7/04 |
· | Tubes; Rings; Hollow bodies [2]

|  | C25D 7/06 |
· | Wires; Strips; Foils [2]

|  | C25D 7/08 |
· | Mirrors; Reflectors [2]

|  | C25D 7/10 |
· | Bearings [2]

|  | C25D 7/12 |
· | Semiconductors [2]

P:80 |  | C25D 9/00 |
Electrolytic coating other than with metals (Fulltext... Hierarchy... Expanded...C25D 11/00, Fulltext... Hierarchy... Expanded...C25D 15/00 take precedence; electrophoretic coating Fulltext... Hierarchy... Expanded...C25D 13/00) [2]

|  | C25D 9/02 |
· | with organic materials [2]

|  | C25D 9/04 |
· | with inorganic materials [2]

|  | C25D 9/06 |
· · | by anodic processes [2]

|  | C25D 9/08 |
· · | by cathodic processes [2]

|  | C25D 9/10 |
· · · | on iron or steel [2]

|  | C25D 9/12 |
· · · | on light metals [2]

P:30 |  | C25D 11/00 |
Electrolytic coating by surface reaction, i.e. forming conversion layers [2]

|  | C25D 11/02 |
· | Anodisation [2]

|  | C25D 11/04 |
· · | of aluminium or alloys based thereon [2]

|  | C25D 11/06 |
· · · | characterised by the electrolytes used [2]

|  | C25D 11/08 |
· · · · | containing inorganic acids [2]

|  | C25D 11/10 |
· · · · | containing organic acids [2]

|  | C25D 11/12 |
· · · | Anodising more than once, e.g. in different baths [2]

|  | C25D 11/14 |
· · · | Producing integrally coloured layers [2]

|  | C25D 11/16 |
· · · | Pretreatment [2]

|  | C25D 11/18 |
· · · | After-treatment, e.g. pore-sealing (lacquering Fulltext... Hierarchy... Expanded...B44D) [2]

|  | C25D 11/20 |
· · · · | Electrolytic after-treatment [2]

|  | C25D 11/22 |
· · · · · | for colouring layers [2]

|  | C25D 11/24 |
· · · · | Chemical after-treatment [2]

|  | C25D 11/26 |
· · | of refractory metals or alloys based thereon [2]

|  | C25D 11/28 |
· · | of actinides or alloys based thereon [2]

|  | C25D 11/30 |
· · | of magnesium or alloys based thereon [2]

|  | C25D 11/32 |
· · | of semiconducting materials [2]

|  | C25D 11/34 |
· · | of metals or alloys not provided for in groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...C25D 11/04-C25D 11/32 [2]

|  | C25D 11/36 |
· | Phosphatising [2]

|  | C25D 11/38 |
· | Chromatising [2]

P:40 |  | C25D 13/00 |
Electrophoretic coating (Fulltext... Hierarchy... Expanded...C25D 15/00 takes precedence; apparatus for continuously conveying articles into baths Fulltext... Hierarchy... Expanded...B65G, e.g. Fulltext... Hierarchy... Expanded...B65G 49/00; compositions for electrophoretic coating Fulltext... Hierarchy... Expanded...C09D 5/44) [2]

|  | C25D 13/02 |
· | with inorganic material [2]

|  | C25D 13/04 |
· | with organic material [2]

|  | C25D 13/06 |
· · | polymers [2]

|  | C25D 13/08 |
· · · | by polymerisation in situ of monomeric materials [2]

|  | C25D 13/10 |
· | characterised by the additives used [2]

|  | C25D 13/12 |
· | characterised by the article coated [2]

|  | C25D 13/14 |
· · | Tubes; Rings; Hollow bodies [2]

|  | C25D 13/16 |
· · | Wires; Strips; Foils [2]

|  | C25D 13/18 |
· | using modulated, pulsed or reversing current [2]

|  | C25D 13/20 |
· | Pretreatment [2]

|  | C25D 13/22 |
· | Servicing or operating [2]

|  | C25D 13/24 |
· · | Regeneration of process liquids [2]

P:20 |  | C25D 15/00 |
Electrolytic or electrophoretic production of coatings containing embedded materials, e.g. particles, whiskers, wires [2]

|  | C25D 15/02 |
· | Combined electrolytic and electrophoretic processes [2]

P:110 |  | C25D 17/00 |
Constructional parts, or assemblies thereof, of cells for electrolytic coating (apparatus for continuously conveying articles into baths Fulltext... Hierarchy... Expanded...B65G, e.g. Fulltext... Hierarchy... Expanded...B65G 49/00; electric devices, see the relevant places, e.g. Fulltext... Hierarchy... Expanded...H01B, Fulltext... Hierarchy... Expanded...H02G) [2]

|  | C25D 17/02 |
· | Tanks; Installations therefor [2]

|  | C25D 17/04 |
· · | External supporting frames or structures [2]

|  | C25D 17/06 |
· | Suspending or supporting devices for articles to be coated [2]

|  | C25D 17/08 |
· · | Racks [2]

|  | C25D 17/10 |
· | Electrodes [2]

|  | C25D 17/12 |
· · | Shape or form (Fulltext... Hierarchy... Expanded...C25D 17/14 takes precedence) [2]

|  | C25D 17/14 |
· · | for pad-plating [2]

|  | C25D 17/16 |
· | Apparatus for electrolytic coating of small objects in bulk [2]

|  | C25D 17/18 |
· · | having closed containers [2]

|  | C25D 17/20 |
· · · | Horizontal barrels [2]

|  | C25D 17/22 |
· · | having open containers [2]

|  | C25D 17/24 |
· · · | Oblique barrels [2]

|  | C25D 17/26 |
· · · | Oscillating baskets [2]

|  | C25D 17/28 |
· · | with means for moving the objects individually through the apparatus during the treatment [2]

P:100 |  | C25D 19/00 |
Electrolytic coating plants [2]

P:90 |  | C25D 21/00 |
Processes for servicing or operating cells for electrolytic coating [2]

|  | C25D 21/02 |
· | Heating or cooling [2]

|  | C25D 21/04 |
· | Removal of gases or vapours [2]

|  | C25D 21/06 |
· | Filtering [2]

|  | C25D 21/08 |
· | Rinsing [2]

|  | C25D 21/10 |
· | Agitating of electrolytes; Moving of racks [2]

|  | C25D 21/11 |
· | Use of protective surface layers on electrolytic baths [3]

|  | C25D 21/12 |
· | Process control or regulation (controlling or regulating in general Fulltext... Hierarchy... Expanded...G05) [2]

|  | C25D 21/14 |
· · | Controlled addition of electrolyte components [2]

|  | C25D 21/16 |
· | Regeneration of process solutions [2]

|  | C25D 21/18 |
· · | of electrolytes (Fulltext... Hierarchy... Expanded...C25D 21/22 takes precedence) [2]

|  | C25D 21/20 |
· · | of rinse-solutions (Fulltext... Hierarchy... Expanded...C25D 21/22 takes precedence) [2]

|  | C25D 21/22 |
· · | by ion-exchange [2]