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
  • C23F11/02—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in air or gases by adding vapour phase inhibitors
• • 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
  • C23F11/14—Nitrogen-containing compounds
  • C23F11/149—Heterocyclic compounds containing nitrogen as hetero atom

Definitions

• This invention relates to methods for inhibiting the corrosion of copper and copper containing alloys (hereinafter: referred to collectively as copper).
• the methods of the invention involve treating the copper with a supply of benzotriazole vapor for a time sufficient to form a thin self-sustaining protec tive film or coating on the copper after which the copper is removed from the treating environment and utilized as desired.
• the success of the invention is based, in large measure, on the finding that by utilizing suitable conditions of application, a self-sustaining film of benzotriazole can be deposited on the copper with the result that the treated metal can be removed from the treating environment and stored, Worked or otherwise used as desired without corrosion.
• Benzotriazole has previously been proposed to inhibit corrosion of copper but in these prior proposals, the inhibiting effect has only been obtained by maintaining the copper in contact with the treating environment and the conditions employed have not been adequate to form a self-sustaining protective film.
• Hatch 2,941,953 describes the addition of small amounts of benzotriazole to a water system in order to avoid corrosion of copper in contact therewith.
• the copper can still corrode just as in the case of copper which has not been subjected to the action of benzotriazole.
• This type of treatment is only effective as long as the copper articles remain wrapped or packaged in the impregnated paper or equivalent so that the copper contacts the paper and/or benzotriazole vapors liberated therefrom.
• the self-sustaining corrosion inhibiting film of benzotriazole is formed by placing the copper in an atmosphere of benzotriazole vapor and the film formed by condensation of vapor on the metal surface.
• the metal is chilled, e.g. with a blast of air, to facilitate the vapor condensation and film formation.
• the temperature of the vapor and the temperature of the chilled metal may be C. to C. and 0 C. to 15 C., respectively.
• a time of treatment of 5 to 15 minutes is usually adequate for present purposes and the atmosphere employed should preferably contain from 0.03 to 0.7 milligram of benzotriazole per liter.
• the metal should be free of grease and oxide prior to the benzotriazole treatment. This may be conveniently accomplished by degreasing and/ or pickling the metal in an acid bath.
• the treated surface is unaffected by moderate handling and it has been found that strip coated in this way may be subjected to as much as rolling reduction without the protection against corrosion becoming impaired.
• copper strip or wire may be given an inte-raprocess treatment with benzotriazole so that it will remain bright and uncorroded until it is required for the next process, even though this may involve a delay of as much as several weeks.
• benzotriazole In processes which involve the use of lubricants which may have :a corrosive effect on the copper, it is possible to add benzotriazole to the lubricant so as to overcome the said effect and at the same time impart a considerable degree of lasting protection.
• Example 1 A set of experiments was carried out using benzotriazole condensed from the vapor onto the sheet, this being achieved by chilling a sample sheet in an air blast after degreasing in trichloroethylene and then suspending the sample in an atmosphere saturated with benzotriazole maintained at about 85 C. The corrosion properties of the thus processed sheet were compared with those of a control sheet which was not treated with benzotr-iazole.
• a method of inhibiting the corrosion of copper by forming thereon a self-sustaining protective film which comprises providing an atmosphere of benzotriazole vapor at a temperature of at least 75 C., placing the copper in said atmosphere at a temperature below the condensation point of said benzotriazole vapor, maintaining the copper in said atmosphere until a self-sustaining protective film is formed thereon and then removing the copper from said atmosphere.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Preventing Corrosion Or Incrustation Of Metals (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=10418804

Family Applications (1)

Country Status (4)

Cited By (16)

Families Citing this family (1)

Citations (6)

• 1959
  • 1959-12-04 GB GB41245/59A patent/GB907793A/en not_active Expired
• 1960
  • 1960-12-02 CH CH1351260A patent/CH399869A/de unknown
  • 1960-12-03 FR FR845866A patent/FR1282023A/fr not_active Expired
• 1965
  • 1965-07-12 US US471423A patent/US3295917A/en not_active Expired - Lifetime

Patent Citations (6)

Also Published As

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