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
  • C23F11/04—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in markedly acid liquids
• • 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

Definitions

• This invention relates to the inhibition of the corrosion of steel by acids.
• Our copending United Kingdom Patent Application No. 45814/70 describes and claims a method of inhibiting the corrosion of steel by acidic compounds which comprises adding to the acidic compound an effective amount of an organic nitrogen compound containing at least one unsaturated carbon-nitrogen bond, or by pretreatment of the steel with the organic nitrogen compound, or by a combination of both methods, provided that the organic nitrogen compound is other than a cyclic vicinal dinitrile.
• a method of inhibiting the corrosion of steel by acidic compounds which comprises adding to the acidic compound an effective amount of a mixture of a nitrile and an oxime or a mixture of a compound selected from nitriles and oximes with at least one compound selected from aliphatic and aromatic aldehydes and ketones and organic amines, or by pre-treatment of the steel with the inhibitor mixture or by a combination of both methods, provided that the nitrile is other than a cyclic vicinal dinitrile.
• nitriles and oximes which may be used there may be mentioned acrylonitrile and substituted acrylonitriles, for example, crotononitrile, cinnamonitrile, o-, mand p-methoxycinnamonitriles, l-
• substituted benzonitriles including pnitrobenzonitrile, p-dimethylaminobenzonitrile, and p-aminobenzonitrile; N,N,N N '-tetrakis- (cyanomethyl)hexamethylenediamine, N,N'-bis(adiphenylmethane nitriles, for example, 3,3'-dicyanodiphenylmethane, diphenylnitriles, for example 4,4'-dicyanodiphenyl, oand p-cyanobenzaldehyde, Z-pentenenitrile, 2,4,6- heptatrienonitrile, cyanoacetic acid, cyanovaleric acid, cyanocaproic acid, 2-3- and 4-cyanopyridines, alkyl nitriles, for example, capronitrile, caprinitrile, cenanthonitrile, caprylonitrile, pelargononitrile, tridecanonitrile,
• benzamideoxime oandp-benzoquinone monoximes and dioximes
• acetophenoneoxime benzophenoneoxime
• benzaldoxime benzaldoxime
• Examples of aliphatic and aromatic aldehydes, ketones and organic amines are acetaldehyde, aldol, propionaldehyde, butyraldehyde, crontonaldehyde, cinnamaldehyde, furfuraldehyde, benzaldehyde, acetone, methyl vinyl ketone, methyl isobutylketone, benzylidene acetone, dibenzylidene acetone, cyclohexanone, cyclopentanone, pyridine, piperidine, morpholine, pyrrolidine, benzylamine, aniline, p-aminodiphenylamine, hexylamine, hexamethylene diamine, hexamethyleneimine, hexamethylenetetramine, cyclohexylamine and dicyclohexylamine.
• Nitriles, oximes, aldehydes and amines which are substituted by hydroxyl, halogen, alkyl, aryl, alkoxy,,
• polyoxyethylene or polyoxypropylene groups may also be used.
• halogens or halide I salts for example, bromine and iodine
• organic acids against the corrosive attack of which the mixtures of compounds are effective there may be mentioned monocarboxylic acids such as formic acid, acetic acid, propionic acid, nbutyric acid, isobutyric acid, stearic acid, monochloro-, dichloro-and trichloroacetic acids and the corresponding bromoacetic acids, lactic acid, dicarboxylic acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, terephthalic acid, suberic acid, azelaic acid, sebacic acid, unde'canedioic and dodecanedioic acid, tartaric acid and tricarboxylic acids such as citric acid and trimesic acid.
• monocarboxylic acids such as formic acid, acetic acid, propionic acid, nbutyric acid, isobutyric acid, stearic acid, monochloro-, dichloro
• the method of the present invention is also effective against attack by organic sulphonic acids.
• inorganic acids the corrosive effects on steel of which are minimised according to the invention, there may be mentioned aqueous sulphurous acid, sulphuric acid, aqueous solutions of hydrogen halides, e.g. hydrochloric acid, sulphamic acid and nitric acid.
• the method is also effective against the corrosion of steels by derivatives of acids which may undergo chemical reaction with consequent liberation of the free acids, for example, anhydrides, esters and amides in the case of carboxylic acids and is applicable both to the anhydrous acids and aqueous solutions thereof.
• derivatives of acids which may undergo chemical reaction with consequent liberation of the free acids, for example, anhydrides, esters and amides in the case of carboxylic acids and is applicable both to the anhydrous acids and aqueous solutions thereof.
• the corrosion-inhibiting mixtures used according to the present invention are effective at temperatures from ambient temperature or below up to 240C or even higher.
• an effective amount we mean an amount of the inhibitor mixture which is effective in inhibiting corrosion under the prevailing conditions.
• the inhibitor mixture is added to the organic or inorganic acid an amount of from 0.001 up to 10% by weight of each component of the mixture may be used. However, it is preferred to use from 0.005 to 5.0% and more particularly 0.01 to 0.5% by weight of each component.
• Pre-treatment of steel with the inhibitor mixture may be carried out using the mixture neat, as vapouror as a solution in a'suitable solvent, for example water, alcohols, acids, bases such as pyridine and quinoline, and nitriles and at temperatures up to 300C.
• a'suitable solvent for example water, alcohols, acids, bases such as pyridine and quinoline, and nitriles and at temperatures up to 300C.
• the inhibitor mixtures may also be incorporated in paints, primers, and wax or polish compositions intended for application to steel and in impregnated interlining and packing materials such as paper intended for wrapping and protecting steel.
• the inhibitor mixtures may also be used as corrosion inhibitors in acid pickling baths which are employed in removing oxide scale from ferrous metals, and these uses form further features of the invention.
• a wide variety of steels may be protected against corrosion using the methods described above, for example, stainless steels of American lron and Steel Institute Types 304, 316 and 321 (the compositions of which are defined in. for example, British Standard No. 1449, part 4, page 20) and mild steels.
• the corrosioninhibiting mixtures of compounds hereinbefore described are also effective in protecting steels from attack by high performance (jet) lubricants.
• the invention is illustrated but not limited by the following Examples.
• a method of inhibiting the corrosion of steel by acidic compounds which comprises adding to the acidic compound a corrosion inhibiting amount of a mixture of a nitrile and an oxime in which the nitrile group or oxime group, or both, form part of a conjugated unsaturated system, or a mixture of a compound selected from said nitrilcs and oximes with at least one compound selected from aliphatic and aromatic aldehydes and ketones and organic amines.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Preventing Corrosion Or Incrustation Of Metals (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Applications Claiming Priority (1)

Publications (1)

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ID=9973117

Family Applications (1)

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Cited By (15)

Citations (5)

• 1972
  • 1972-03-08 GB GB1072472A patent/GB1417555A/en not_active Expired
• 1973
  • 1973-03-06 US US00338526A patent/US3854959A/en not_active Expired - Lifetime
  • 1973-03-07 NL NL7303191A patent/NL7303191A/xx unknown
  • 1973-03-07 DE DE19732311171 patent/DE2311171A1/de active Pending
  • 1973-03-07 FR FR7308176A patent/FR2175149B2/fr not_active Expired
  • 1973-03-08 BE BE128554A patent/BE796487A/xx unknown
  • 1973-03-08 JP JP48027552A patent/JPS48102043A/ja active Pending
  • 1973-03-08 IT IT21334/73A patent/IT1045616B/it active

Patent Citations (5)

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