Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
  • C23F11/00—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
  • C23F11/08—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids
  • C23F11/10—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids using organic inhibitors
  • C23F11/16—Sulfur-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/16—Organic compounds
  • C11D3/34—Organic compounds containing sulfur
  • C11D3/3436—Organic compounds containing sulfur containing disulfide groups
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
  • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
  • C23G1/04—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors
  • C23G1/06—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors organic inhibitors
  • C23G1/063—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors organic inhibitors heterocyclic compounds

Definitions

• the preparation may be, inter alia, in liquid, paste, cream, dip or solid formor, can be applied to the surface to be protected by impregnating a suitable material such as cloth with the preparation and then wiping the surface with the cloth.
• the amount of dialkyl disulphide ranges from 0.1% to by weight; amounts as low as 0.5 by weight have been found to be particularly advantageous.
• the cleaning and/or polishing preparation can contain any of the usual ingredients including descaling, etching, abrasive and polishing agents.
• the present invention is concerned with protecting noble and coinage metals against disfiguration through the action of the atmosphere.
• the present invention comprises preparations which provide long term protection for silver, copper and nickel surfaces against tarnish.
• a dialkyl disulphide of the formula RSSR wherein R is an alkyl group having from 8 to 22 carbon atoms in the alkyl chain as a protective medium in any known silver, copper or nickel cleaning and/or polishing preparation provides a high degree of protection to the surface against tarnish.
• These preparations which can be prepared, inter alia, in liquid, cream, paste, dip and solid form, may also include descaling, etching, abrasive and polishing agents.
• the dialkyl disulphide may also be applied to the surface to be protected by impregnating a cloth or other suitable material with the preparation and then using the cloth to wipe the surface. Particularly effective results have been achieved when the alkyl group has 12 or more carbon atoms.
• a dialkyl disulphide of the formula RSSR wherein R is an alkyl group having from 8 to 22 carbon atoms in the alkyl chain as a protective medium to a silver, copper or nickel surface to be protected, provides tarnish protection over a prolonged period.
• the dialkyl disulphide is applied to the surface by application of a cleaning and/ or polishing preparation containing 0.1% to 50% by weight of the dialkyl disulphide. 0.5% has been found to be an effective amount.
• a cleaning and/or polishing preparation containing 0.1% to 50% by weight of the dialkyl disulphide. 0.5% has been found to be an effective amount.
• Any of the known ingredients presently incorporated in such preparations such as pickling, descaling, etching, abrasive, brightening and polish agents may also be present.
• a cloth is impregnated With a cleaning and/or polishing preparation containing the dialkyl disulphide and then the surface to be protected is wiped with the cloth.
• the preparations of the present invention and the impregnated cloths have been found to be particularly effective in protecting silver surfaces against tarnish.
• dialkyl disulphides should be capable of providing an invisible, transparent, colorless layer which protects surfaces against tarnish and is sufliciently robust to withstand the polishing action of an abrasive.
• a long chain mercaptan introduced into an alcoholic solution of silver nitrate gives a heavy yellow precipitate.
• a long chain ester of a mercapto carboxylic acid gives a light white precipitate.
• mercaptans have a most unpleasant smell which makes them domestically unacceptable without a strong disguising odor such as Wintergreen.
• Mercaptans are much less stable than dialkyl disulphides having a corresponding number of carbon atoms in the alkyl chain and consequently are more toxic both before and after use.
• Metal ware cleaned with preparations according to the invention and according to the prior art often retains on the surface a small amount of the polishing preparation. Such ware may be cutlery or a teapot which may come into contact with food-stuffs.
• Exemplary kinds of polish preparations which are suitable for carrying the dialkyl disulphide are liquid polishing preparations, polishing pastes or creams, emulsion polishes, and solvent based polishes, as well as polishing powder, polishing powder impregnated cloths, and solid polishes in block form.
• Metal protective solutions com- Polishing Protective medium, medium,
• Polish paste 10-70 0. 1-20 150% detergent. Emulsion polish 5-50 1-20 5-00% hydrocarbon. Solvent based p 5-50 0 1-20 30-90% hydrocarbon. Polishing powder. 50-99 1-50 Liquid preparation 0 1-50 50-99.9% alcohol.
• the dialkyl disulphide protective medium may simply be mixed with the polishing medium but is generally melted and then added to an alcohol. The resulting mixture can then be incorporated with the other intended ingredients of the preparation.
• the polishing medium is added to the alcohol solution and stirred in vigorously to give a viscous mixture. If a liquid polish is to be produced water is then added in small additions possibly with more polishing powder and stirring.
• a surface active agent may be added if desired to improve the covering power of the material.
• the exact number of carbon atoms in the long chain alkyl groups in protective media used according to the invention does not greatly vary the protective properties so long as there are at least 8 carbon atoms and preferably at least 14 or 16 carbon atoms in the alkyl chain.
• Short chain dialkyl disulphides may actually hasten the tarnish of a silver surface in the atmosphere. While 22 carbon atom chains have been indicated as the practical upper range, effective protection is provided by long chain dialkyl disulphides and chains in excess of 22 can also be utilized. The selection of any particular chain length is made on the basis of considerations such as price and commercial availability, as the protective effectiveness of the long chain compounds varies only slightly. Distearyl, dipalmityl (dihexadecyl) disulphides have been found to be particularly effective.
• a liquid polishing preparation suitable for use on surfaces containing silver, copper or nickel contains the following substances in admixture:
• the distearyl disulphide is melted and is then added to the alcohol. Sufiicient of the polishing powder is then added with vigorous stirring until a fairly viscous mixture is obtained. Stirring is continued with a high shear action, some water is added, and then alternate additions of polishing powder and water are made until the mixture is complete.
• the resultant mixture has a dispersion of disulphide on the surface of the polishing powder which is in turn homogeneously dispersed in the aqueous alcoholic liquid.
• bentonite A may be incorporated in the proportion of about 2 to 4% by forming a gel with part of the water. This gel may be added to the viscous mixture aforesaid before the addition of water thereto.
• the disulphide is first warmed with an equal weight of detergent paste and the resulting liquid is added to the dry ingredients whilst being stirred. The formation of the stiff paste ensures homogenising of the final product. Afterwards the liquid content is added slowly while the mixture is stirred.
• EXAMPLE 3 An emulsion for metal surfaces as aforesaid is made up from the following ingredients:
• a solvent based paste polish (as opposed to a water based paste polish such as in Example 2) is made up from the following ingredients:
• a cleaning and polishing powder for use on metal surfaces as aforesaid comprises the following:
• Grams Polishing powder kieselguhr 98 Distearyl disulphide 62 These constituents are thoroughly blended by grinding.
• the resulting preparation may be used as such or may be incorporated into a suitable polishing cloth or braid, for example.
• EXAMPLE 6 preparation suitable for treating metal surfaces as above mentioned by immersion therein or for adding in a small proportion to various kinds of baths as in Example 6 is made up of the following constituents:
• a solid polishing composition suitable for mechanical application comprises the following:
• a new article of manufacture for use on surfaces of silver, copper, nickel, or alloys thereof to prevent tarnish which comprises a cloth material impregnated with a preparation containing as the essential active ingredient from 0.1% to by weight of a dialkyl disulphide of the formula RSSR, wherein R is alkyl of 8 to 22 carbon atoms.
• R is alkyl of 12 to 22 carbon atoms.
• a method of providing prolonged protection against tarnishing to surfaces of silver, copper, nickel or alloys thereof which comprises applying to such surfaces a dialkyl disulphide of the formula RSSR, wherein R is alkyl having 8 to 22 carbon atoms in an amount sufficient to inhibit tarnish.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Detergent Compositions (AREA)
• Cleaning Implements For Floors, Carpets, Furniture, Walls, And The Like (AREA)
• Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

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Cited By (7)

Citations (5)

Family Cites Families (2)

• 1964
  • 1964-08-19 GB GB33864/64A patent/GB1070384A/en not_active Expired
• 1965
  • 1965-08-18 DE DEG44460A patent/DE1243808B/de active Pending
• 1967
  • 1967-06-19 US US647187A patent/US3503883A/en not_active Expired - Lifetime

Patent Citations (5)

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