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CLEANING OR DEGREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS (polishing compositions C09G; detergents in general C11D)
Definition statement
This subclass/group covers:

Methods and compositions for cleaning or pickling metallic material by chemical means, e.g. with acidic, alkaline, neutral solutions or with molten salts (C23G 1/00 - C23G 1/34).

Regeneration of waste pickling liquors (C23G 1/36).

Apparatus for cleaning or pickling metallic material (C23G 3/00).

Apparatus for cleaning or pickling wires, strips, filaments continuously (C23G 3/02).

Associated apparatus for pretreating or after-treating (C23G 3/027).

Apparatus for cleaning or pickling pipes (C23G 3/04).

Other non-mechanical methods for cleaning or de-greasing metallic material e.g. by using gases, plasma, supercritical fluids, metastable compositions, etc., but not only by using a solution (C23G 5/00).

Methods and compositions for cleaning or de-greasing metallic material with organic solvents (C23G 5/02).

Apparatus for cleaning or de-greasing metallic material with organic solvents (C23G 5/04).

Methods, compositions and apparatus for cleaning or de-greasing metallic material with emulsions (C23G 5/06).

Methods, compositions and apparatus for stripping non-metallic inorganic coatings from metallic substrates (C23G).

Relationship between large subject matter areas

Particular cleaning of specific articles is not to be classified in this subclass but in the appropriate places, e.g. B08B, F23J, F28G, F01D, F02M, F02B.

Cleaning apparatus receives an additional or only a classification symbol in B08B, B21B, B65G. Apparatus not specially adapted for cleaning metals is not classified in C23G.

Methods for etching metallic materials are classified in C23F and methods for cleaning or pickling metallic material by chemical means (no attack or removal or dissolution of metal) are classified in C23G.

If a composition is used for specific cleaning or polishing a metallic surface, it will be classified in C23G (cleaning) or C23F 3/00 (brightening).

Compositions for polishing and cleaning metallic surfaces are classified in C09G and in C23F, e.g. EP1793016, EP1572821.

Methods and compositions for pickling and brightening metallic surfaces are classified in C23G and C23F, e.g. WO2008123147, US5538152.

Methods and compositions for pickling and passivating metallic surfaces are classified in C23F and C23C 22/00 , e.g. EP1552035.

Cleaning with azeotropic mixtures is classified in C11D and receive an additional classification symbol in C23G only the specific examples of the use of azeotropic cleaning mixtures for cleaning metals, e.g. EP0607969, EP0697452.

References relevant to classification in this subclass
This subclass/group does not cover:
Methods and apparatus for cleaning in general
Polishing compositions in general
Detergents in general
Electrolytic pickling, cleaning or de-greasing
Separation of solids by wet methods
Devices for guiding or conveying wires, sheet metal bands in loops or curves
Devices for surface cleaning
Devices for de-scaling
Devices for winding-up, coiling or winding-off metal wire, metal band or other flexible metal material
Cleaning prior to soldering, brazing
Apparatus for continuously conveying articles into bath
Methods for preparing inorganic compounds
C01
Azeotropic mixtures for cleaning applications
Special cleaning and washing methods characterized by the object to be cleaned
Cleaning of semiconductor devices or of parts thereof
Cleaning or polishing of the conductive pattern
Informative references
Attention is drawn to the following places, which may be of interest for search:
Cleaning involving the use of liquid or steam
Cleaning by the force of jets or sprays
Cleaning involving contact with liquid
Cleaning involving contact with a liquid having chemical or dissolving effect
Regenerating cleaning liquids
Cleaning by other methods
Cleaning of pipes or tubes in general
Cleaning containers, e.g. tanks
Devices for guiding or conveying wires, sheet metal bands in loops or curves
Devices for surface cleaning
Devices for surface de-scaling, e.g. of strip material, hydraulically
Cleaning prior to soldering, brazing
Apparatus for continuously conveying articles into bath
Cleaning devices
Special cleaning or washing methods for metals
Special cleaning or washing methods for industrial or commercial equipment, e.g. reactors, tubes, engines
Special cleaning or washing methods for electronic devices, e.g. PCB's
Production or refining of metals, e.g. by wet processes for recovering metals from spent pickling solutions
Chemical treatment of the metal surface prior to hot-dipping coatings
Chemical treatment of the metal surface prior to diffusion coatings
Cleaning of the metal surface prior to PVD coatings
Cleaning of the metal surface prior to CVD coating
Chemical treatment of metal surfaces prior to coating with enamel
Regeneration of process liquids
Chemical or electrochemical decontamination of radioactively contaminated metallic material and apparatus thereof, e.g. removal of metal oxides from the metal surface
Cleaning of turbomachines
Cleaning of combustion engines
Cleaning of fuel injection apparatuses
Cleaning furnaces tubes
Cleaning heat-exchangers or heat-transfer conduits with chemical solvents
Cleaning of semiconductor devices or of parts thereof
Cleaning or polishing of the conductive pattern
Special rules of classification within this subclass

This subclass (C23G) does not cover methods, compositions and apparatus for treatment of non-metallic material.

Classification of additional information

In many cases the classification of additional information is very useful for retrieving the document, and therefore very desirable, although not compulsory.

Well-disclosed and non-trivial aspects are classified.

Well-known (trivial) aspects or features are not classified.

Subgroups and head groups

Apparatus is classified in the groups or subgroups for apparatus, if such groups or subgroups exist, if not the apparatus is classified in the head group.

Cleaning or pickling /de-greasing compositions for are classified in the specific subgroups according to the intrinsic nature /function of the mixture or composition, e.g. acidic aqueous cleaning or pickling composition (C23G 1/02) or alkaline aqueous cleaning or pickling compositions (C23G 1/14).

An "application-oriented" invention should be classified in an application-oriented place (when it exits). An "application-oriented" invention is considered as:

- a thing "specially adapted for" a particular use or purpose, e.g. an apparatus modified or particularly constructed for cleaning or pickling pipes (C23G 3/04) or for cleaning strips, wires or filament continuously (C23G 1/02);

- a particular use or application of a thing; e.g. acidic cleaning or pickling of copper or alloys thereof (C23G 1/103).

If a document concerns embodiments which are covered by several subgroups (e.g. C23G 1/061 - C23G 1/068) dependent on a higher hierarchy group (head group, e.g. C23G 1/06), the following rules apply:

the specific technical information relevant for some of the subgroups is classified (EC) in all said subgroups;

if relevant, the combination of the elements covered by the subgroups is classified (EC) in the head group;

analogously, if generic technical information common to all of the subgroups is disclosed and only schematic embodiments of the specific subgroup embodiments are represented, the document is classified (EC) in the head group.

For example:

If a document discloses an acidic cleaning or pickling composition comprising nitrogen- containing compounds and sulfur-containing compounds as organic inhibitors, and the specific technical information is relevant for both organic inhibitors then it is classified in both subgroups C23G 1/061 and C23G 1/065.

A clear difference has to be made between the word "fouling" with the above meaning and the word "fouling" used with the meaning " accumulation of particulates of microorganisms of the surface" classified in B08B 17/00.

A clear difference has to be made between the word "scale" with the above meaning and the word "scale" used with the meaning "white rust" "staining", "incrustation" "carbonate, sulphate, sulphide, silicate, oxalate scale" or "hydrocarbon scale" classified in C23F 14/00, C23F 15/00.

Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Metallic material
covers metals and alloys
Pickling of metallic material
Chemical removal or dissolution of surface deposits of inorganic contaminants, such as rust (iron oxides), or scale from ferrous metals, copper or aluminium alloys, or corrosion products from metallic surfaces. Chemical stripping of non-metallic inorganic coatings from metallic substrates, e.g. US2007023943, EP0434622.
De-greasing of metallic material
Non-mechanical removal or dissolution of surface deposits of organic contaminants, such as oils, fats, greases, dust, finger-print contaminations, or similar hydrophobic compounds from metallic surfaces.
Synonyms and Keywords

In patent documents the following words " pickling ", " stripping", "deoxidizing", "cleaning", "derusting", "descaling", "defouling", "detarnishing" and "oxides removal" are often used as synonyms.

In patent documents the following words "de-greasing", "cleaning", "deoiling", "defating", and "decontaminating" are often used as synonyms.

In patent documents the following words "pickling", "cleaning" and "descaling" are often used as synonyms.

In patent documents the word "etching" is often used with the meaning "pickling".

In patent documents the word "fouling" is often used with the meaning "rusting".

In patent documents the word "scale" is often used with the meaning "rust" or " scale from ferrous metals, copper or aluminium alloys" or "rust staining".

Cleaning or pickling metallic material with solutions or molten salts (with organic solvents C23G 5/02)
Definition statement
This subclass/group covers:

Methods and compositions for cleaning or pickling metallic material by chemical means, e.g. with acidic, alkaline, neutral solutions or with molten salts.

Multi-step methods for cleaning or pickling metallic material (C23G 1/00).

Regeneration of waste pickling liquors (C23G 1/36).

References relevant to classification in this group
This subclass/group does not cover:
Apparatus for cleaning or pickling metallic material
Cleaning or de-greasing of metallic material by other non-mechanical means
Cleaning or de-greasing of metallic material with organic solvents
Cleaning or de-greasing of metallic material with emulsions
Informative references
Attention is drawn to the following places, which may be of interest for search:
Cleaning involving contact with liquid
Cleaning with additional treatment of the liquid or of the object being cleaned, e.g. by heat, vibration, electricity, by using propellers, etc.
Regenerating cleaning liquids
Cleaning of pipes or tubes in general
Cleaning containers, e.g. tanks
Methods for preparing inorganic compounds
Polishing or cleaning compositions
Etching, surface-brightening or pickling composition in general, e.g. for removing metal oxides, nitrides
Special cleaning or washing methods for metals
Special cleaning or washing methods for industrial or commercial equipment, e.g. reactors, tubes, engines
Special cleaning or washing methods for electronic devices, e.g. PCB's
Production or refining of metals, e.g. by wet processes for recovering metals from spent pickling solutions
Chemical treatment of the metal surface prior to diffusion coatings
Cleaning of the metal surface prior to PVD coatings
Cleaning of the metal surface prior to CVD coating
Chemical treatment of metal surfaces prior to coating with enamel
Regeneration of etching compositions
Regeneration of process liquids
Repairing of turbine blades
Cleaning of turbomachines
Cleaning furnaces tubes
Cleaning heat-exchangers or heat-transfer conduits with chemical solvents
Chemical or electrochemical decontamination of radioactively contaminated metallic material and apparatus thereof, e.g. removal of metal oxides from the metal surface
Cleaning of semiconductor devices or of parts thereof
Cleaning or polishing of the conductive pattern
Special rules of classification within this group

In the head group C23G 1/00, the specific technical information is relevant to a multi-step process for cleaning or pickling metallic material with solutions or molten salts, e.g. a two-step pickling method comprising a first treatment step with an alkaline solution and a second treatment step with an acidic solution.

In the subgroup C23G 1/02 the specific technical information is relevant to the cleaning or pickling metallic material with acidic solutions.

In the subgroup C23G 1/025 the specific technical information is relevant to the cleaning or pickling metallic material with acidic pastes.

In the subgroup C23G 1/04 the specific technical information is relevant to the cleaning or pickling metallic material with acidic solutions comprising inhibitors, e.g. inorganic inhibitors or a mixture of inorganic and organic inhibitors.

In the subgroup C23G 1/06 the specific technical information is relevant cleaning or pickling metallic material with acidic solutions comprising only organic inhibitors.

In the subgroup C23G 1/08 the specific technical information is relevant to the cleaning or pickling iron or steel with acidic solutions.

In the range C23G 1/08 - C23G 1/088 the cleaning or pickling iron or steel with acidic compositions are classified in the last appropriate place (last place rule).

In the subgroup C23G 1/10 the specific technical information is relevant to the cleaning or pickling other heavy metals with acidic solutions.

In the subgroup C23G 1/12 the specific technical information is relevant to the cleaning or pickling light metals with acidic solutions.

In the subgroup C23G 1/14 the specific technical information is relevant to the cleaning or pickling metallic material with alkaline solutions.

In the subgroup C23G 1/16 the specific technical information is relevant to the cleaning or pickling metallic material with alkaline solutions comprising inhibitors, e.g. inorganic inhibitors or a mixture of inorganic and organic inhibitors.

In the subgroup C23G 1/18 the specific technical information is relevant cleaning or pickling metallic material with alkaline solutions comprising only organic inhibitors.

In the subgroup C23G 1/19 the specific technical information is relevant to the cleaning or pickling iron or steel with alkaline solutions.

In the subgroup C23G 1/20 the specific technical information is relevant to the cleaning or pickling other heavy metals with alkaline solutions.

In the subgroup C23G 1/22 the specific technical information is relevant to the cleaning or pickling light metals with alkaline solutions.

In the subgroup C23G 1/24 the specific technical information is relevant to the cleaning or pickling metallic material with neutral solutions.

In the subgroup C23G 1/26 the specific technical information is relevant to the cleaning or pickling metallic material with neutral solutions comprising inhibitors, e.g. inorganic inhibitors or a mixture of inorganic and organic inhibitors.

In the subgroup C23G 1/28 the specific technical information is relevant to the cleaning or pickling metallic material with molten salts.

In the subgroup C23G 1/30 the specific technical information is relevant to the cleaning or pickling metallic material with molten salts comprising inhibitors, e.g. inorganic inhibitors or a mixture of inorganic and organic inhibitors, only organic inhibitors are almost impossible, because they will be destroyed by the presence of molten salts. This subgroup is empty (0 documents). It is advised not to be used for classification, if it is, then only in combination with the subgroups C23G 1/32 or C23G 1/34.

Synonyms and Keywords

In patent documents the following words " pickling ", " stripping", "deoxidizing", "cleaning", "derusting", "descaling", "defouling", "detarnishing" and "oxides removal" are often used as synonyms.

Apparatus for cleaning or pickling metallic material (with organic solvents C23G 5/04; [N: apparatus for continuously conveying articles into baths B65G])
Definition statement
This subclass/group covers:

Apparatus for cleaning or pickling metallic material by chemical means, e.g. with acidic, alkaline, neutral solutions or with molten salts (C23G 3/00).

Apparatus for cleaning or pickling wires, strips, filaments, continuously by chemical means, e.g. with acidic, alkaline, neutral solutions or with molten salts (C23G 3/02).

Associated apparatus for pretreating or after-treating (C23G 3/027).

Apparatus for cleaning or pickling metallic pipes by chemical means, e.g. with acidic, alkaline, neutral solutions or with molten salts (C23G 3/04).

References relevant to classification in this group
This subclass/group does not cover:
Other apparatus for non-mechanical cleaning or de-greasing metallic material
Apparatus for cleaning or de-greasing metallic material with organic solvents
Apparatus for cleaning or de-greasing metallic material with emulsions
Informative references
Attention is drawn to the following places, which may be of interest for search:
Cleaning travelling work
Cleaning with additional treatment of the liquid or of the object being cleaned, e.g. by heat, vibration, electricity, by using propellers, etc.
Devices for guiding or conveying wires, sheet metal bands in loops or curves
Devices for surface cleaning
Devices for surface de-scaling, e.g. of strip material, hydraulically
Apparatus for continuously conveying articles into bath
Investigating or analyzing materials by optical means
Investigating or analyzing materials by electric, electro-chemical or magnetic means
Investigating or analyzing metals by specific methods
Special rules of classification within this group

In the head group C23G 3/00, the specific technical information is relevant to apparatus for cleaning or pickling metallic material, such as pieces, wafers, articles, etc., with solutions or molten salts.

In the subgroup C23G 3/02 the specific technical information is relevant to apparatus for cleaning or pickling metallic wires, strips, filaments continuously with solutions or molten salts.

In the subgroup C23G 3/027 the specific technical information is relevant to associated apparatus for pretreating or after-treating metallic wires, strips, filaments continuously with solutions or molten salts.

In the subgroup C23G 3/04 the specific technical information is relevant to apparatus for cleaning or pickling pipes with solutions or molten salts.

Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Pickling wires, strips, filaments continuously
pickling coiled wires, strips, filaments or pickling metallic material of continuous length, but not wafers, pieces, articles.
Synonyms and Keywords

In patent documents the following words " continuous length " and " coiled " are often used as synonyms.

Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
Definition statement
This subclass/group covers:

Other methods, compositions and apparatus for non-mechanical cleaning or de-greasing metallic material e.g. by using gases, ion beams, plasma, freezing or cooling, supercritical fluids, melts (applying a coating which is a fondant for another coating), ultrasonic's, by removing liquid contaminants by suction, by using reactive solids, followed by heating, two-phase cleaning mixtures, e.g. air under pressure in combination with an aqueous solution (C23G 5/00).

Methods and compositions for cleaning or de-greasing metallic material with organic solvents (C23G 5/02).

Apparatus for cleaning or de-greasing metallic material with organic solvents (C23G 5/04).

Methods, compositions and apparatus for cleaning or de-greasing metallic material with emulsions (C23G 5/06).

References relevant to classification in this group
This subclass/group does not cover:
Cleaning or pickling metallic material with solutions or molten salts
Apparatuses for cleaning or de-greasing metallic material with solutions or molten salts
Informative references
Attention is drawn to the following places, which may be of interest for search:
Cleaning involving the use of liquid or steam
Cleaning involving contact with a liquid having chemical or dissolving effect
Other cleaning methods
Cleaning by incorporation in a layer which is removed with the contaminants
Cleaning by using liquid gases or supercritical fluids
Cleaning by using radiant energy, e.g. by using plasma, laser
Cleaning by temperature changes; by heating or by cooling
Devices for surface descaling, e.g. of strip material
Cleaning prior to soldering or brazing
Apparatus for continuously conveying articles into bath
Azeotropic mixtures for cleaning applications
Repairing of turbine blades
Cleaning of turbomachines
Drying a solid material by other processes not by heating, e.g., by treating with a chemical liquid, be freezing, suction
Cleaning furnaces tubes
Cleaning heat-exchangers or heat-transfer conduits with chemical solvents
Investigating or analyzing materials by optical means
Cleaning of semiconductor devices or of parts thereof
Special rules of classification within this group

In the head group C23G 5/00, the specific technical information is relevant to other methods, compositions and apparatuses for non-mechanical cleaning or de-greasing metallic material, e.g. by using:

gases such as a halogenous gas mixture (EP2192209), a fluoride ion cleaning (US2007087208), a carbon dioxide cleaning (EP1618970);

ion beams (EP0506304);

plasma (WO2011045667, EP0483839);

freezing or cooling (US2003188766);

supercritical fluids (US2005189001);

melts (by applying a coating which is a fondant for another coating) (US3552404);

ultrasonic's (US3096774, GB973661, US4100926, US5345958);

by removing liquid contaminants by suction (EP1757677, WO03080261, US5565070);

by using reactive solids followed by heating (US5405428, WO9201825); or

by using two-phase cleaning mixtures, e.g. air under pressure in combination with an aqueous solution;

but not only by using a solution.

In subgroups C23G 5/02 - C23G5/36, cleaning with organic solvents, in the absence of an indication to the contrary, classification is made in the last appropriate place (last place rule).

In subgroups C23G 5/02 - C23G5/36, the mixtures of organic solvents are classified according to the major component in the mixture.

The subgroup C23G 5/02854, cleaning or de-greasing metallic material with organic solvents containing halogenated hydrocarbons characterized by the stabilising or corrosion inhibiting additive, contains only 5 documents. It is advised not to be used for classification, if the specific technical information is relevant to the corrosion inhibiting additive, then it is classified with the subgroups C23G 5/02858 to C23G 5/02896.

In the subgroup C23G 3/04 the specific technical information is relevant to apparatuses for cleaning or de-greasing metallic material with organic solvents.

In the subgroup C23G3/06 the specific technical information is relevant to apparatus for cleaning or de-greasing metallic material with emulsions, e.g. aqueous emulsions.

In the group C23G 5/00 only specific examples of the use of azeotropic cleaning mixtures for cleaning metals are classified:

For example cleaning using azeotropic mixture of dichloro-pentafluoropropane and 1,1-dichloroethane is classified in C11D 7/5059, C11D 7/5081 and also in C23G 5/02851 (EP0450856).

Synonyms and Keywords

In patent documents the following abbreviations often used:

Supercritical fluids
dense fluids
Azeotropic mixture
constant boiling mixtures, mixing solvents, stable non-flammable mixture
Cryogenic fluids
cryogenic aerosols
Plasma
discharge, reactive ion etching, DC, AC, RF, HF, UHF, MW, Hz, MHz, GHz
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Last Modified: 10/11/2013