C
SECTION C — CHEMISTRY; METALLURGY
 C

Note(s)

  1. 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

  2. Section C covers:
    1. pure chemistry, which covers inorganic compounds, organic compounds, macromolecular compounds, and their methods of preparation;
    2. 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;
    3. 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;
    4. 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;
    5. metallurgy, ferrous or non-ferrous alloys.
    1. 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.
    2. 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 C03 and not by class F27.
    3. There are, however, some exceptions in which the mechanical (or non-chemical) aspect carries with it the chemical aspect, for example:
    4. 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:
    5. 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 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 D06M 11/83; decorating textiles by locally metallising 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 H01C 17/06); INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL (treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D, C25F)  [2]
 C23

Note(s)

In this class, the following expression is used with the meaning indicated:

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

Note(s)

Processes using enzymes or micro-organisms in order to:

  1. liberate, separate or purify a pre-existing compound or composition, or to
  2. treat textiles or clean solid surfaces of materials
are further classified in subclass C12S.  [5]

P:0 C23G 1/00
Cleaning or pickling metallic material with solutions or molten salts (with organic solvents C23G 5/02)
 C23G 1/02
·  with acid solutions
 C23G 1/04
·  ·  using inhibitors
 C23G 1/06
·  ·  ·  organic inhibitors
 C23G 1/08
·  ·  Iron or steel
 C23G 1/10
·  ·  Other heavy metals
 C23G 1/12
·  ·  Light metals
 C23G 1/14
·  with alkaline solutions
 C23G 1/16
·  ·  using inhibitors
 C23G 1/18
·  ·  ·  Organic inhibitors
 C23G 1/19
·  ·  Iron or steel  [4]
 C23G 1/20
·  ·  Other heavy metals  [4]
 C23G 1/22
·  ·  Light metals
 C23G 1/24
·  with neutral solutions
 C23G 1/26
·  ·  using inhibitors
 C23G 1/28
·  with molten salts
 C23G 1/30
·  ·  using inhibitors
 C23G 1/32
·  ·  Heavy metals
 C23G 1/34
·  ·  Light metals
 C23G 1/36
·  Regeneration of waste pickling liquors
P:20 C23G 3/00
Apparatus for cleaning or pickling metallic material (with organic solvents C23G 5/04)
 C23G 3/02
·  for cleaning wires, strips, filaments continuously
 C23G 3/04
·  for cleaning pipes
P:10 C23G 5/00
Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
 C23G 5/02 - 
C23G 5/06

Note(s)

In groups C23G 5/02-C23G 5/06, in the absence of an indication to the contrary, classification is made in the last appropriate place.  [4]

 C23G 5/02
·  using organic solvents
 C23G 5/024
·  ·  containing hydrocarbons  [4]
 C23G 5/028
·  ·  containing halogenated hydrocarbons  [4]
 C23G 5/032
·  ·  containing oxygen-containing compounds  [4]
 C23G 5/036
·  ·  ·  having also nitrogen  [4]
 C23G 5/04
·  ·  Apparatus
 C23G 5/06
·  using emulsions  [4]