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
  • 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
  • C23G1/065—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors organic inhibitors sulfur-containing compounds

Definitions

• inhibitors are added to the acid bath which serve to prevent, to a large extent, the non-corroded metal surface from being attacked by the acid pickling bath after the overlying layer of rust or foreign matter has been removed by the pickling bath.
• the same principle can be applied to the pretreatment of objects made from other types of metals, such as, for example, from zinc or aluminum.
• a satisfactory and desirable inhibitor must fulfill many requirements to meet the demands of industry. For example, a high-grade inhibitor must give a maximum degree of protection within relatively low ranges of concentration; it must also impart a lasting inhibiting effect to acid pickling baths, so that these baths can remain in operation for long periods of time without constant surveillance; furthermore, it is expected of such inhibitors that they be effective over wide ranges of temperature and concentration; moreover, a good inhibitor must be effective when used in conjunction with a variety of pickling acids and metals; finally, a modern inhibitor is expected to be practicaly non-volatile, even when used in the presence of ordinary or acid-containing steam, nonpoisonous, not prone to generating interfering gases, and practically odorless, a property which many of the old sulfur-containing inhibitors generally lacked.
• Another object of this invention is to provide inhibitors for acid pickling baths which will give a maximum degree of inhibiting protection within relatively low ranges of concentration.
• Another object of this invention is to provide inhibitors for acid pickling baths which will impart a lasting inhibiting effect to such baths.
• Still another object of this invention is to provide inhibitors for acid pickling baths which will give elfective inhibiting protection over wide ranges of concentration and temperature.
• a further object of this invention is to provide inhibitors for acid pickling baths which can be used in conjunction with a large variety of pickling acids and metals.
• G represents an organic radical which contains a carbon atom linked, on one hand, exclusively to heteroatoms and, on the other hand, to the RSO H radical through a sulfur atom and R is a bivalent aliphatic radical containing from 1 to 6 carbon atoms which may carry one or more substituents.
• This class of sulfonic acids is derived from thiourea, for example, as well as from 2-thioimidazoles or Z-benzimidazoles if the carbon atom and the nitrogen atoms form a part of a heterocyclic ring system.
• N This structure occurs in sulfonic acids which are derived, for example, from Z-mercaptothiazoles or 2-mercaptobenzothiazoles, or from thiocyanides.
• thioxanthic acids are derived from thioxanthic acids or trithiocarbonic acids.
• Sulfonic acid compounds having this type of structure are derived from xanthic acids.
• R represents an aliphatic radical having from 1 to 6 carbon atoms, as defined above, and the open bonds may be linked to hydrogen atoms or to aliphatic, cycloaliphatic or aromatic hydrocarbon radicals.
• the hydrocarbon radicals attached to the open bonds may also be interconnected by linkage bonds and may, in addition, carry substituents or contain further 'heteroatoms or heteroatom groups.
• Sulfonic acid compounds of the type herein referred to can be obtained by very simple methods and with excellent yields; for example, by reacting the corresponding sulfhydryl compounds or enolizable thiocarbony-l compounds with cyclic anhydrides of oxyalkanesulfonic acids (sulftones).
• the followng sulfonic acid compounds are examples of compounds having the above general structural formula which can be used as corrosion-preventing additives or inhibitors for acid pickling baths in accordance with our invention:
• sulfonic acid inhibitors required to give the desired inhibiting effects in accordance with our inventon vary within rather wide limits and depend largely upon the type of acid agent employed to make up the pickling solution, upon the metal treated, and under certain circumstances also upon the temperature at which the acid treatment takes place. However, as a rule it is sufiicient to add from 0. 01 to 0.5% of inhibitor based upon the weight of acid present.
• the sulfonic acid inhibitors can be used in accordance with our invention in conjunction with other known corrosion-preventing agents without any danger of incompatibility.
• the inhibitors of our invention are'etfective' in pickling baths made from mineral acids as well as from inorganic or organic acid salts of such mineral acids.
• pickling baths modified with the sulfonic acid inhibitors in accordance with our invention can be used upon any type of metal capable of being subjected to an acid surface treatment for the purpose of cleaning, etching, removal of rust and dirt, and the like.
• the method of cleansing the surface of metal objects which comprises contacting saidobjects with an aqueous solution of a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid, and from about 0.01 to about 0.5% by weight, based upon the weight of acid, of N,N-diethyl-dithiocarbamic acid-n-butylester-w-sodium sulfonate.
• a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid
• the method of cleansing the surface of metal which comprises contacting said objects with an aqueous solution of a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid, and from about 0.01 to about 0.5% by weight, based upon the weight of acid, of N,N-dibutyl-dithiocarbamic acid-n-propylmter-w-sodium sulfonate.
• a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid
• the method of cleansing the surface of metal ob jects which comprises contacting said objects with an aqueous solution of a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid, and from about 0.01 to about 0.5% by weight, based upon the weight of acid, of N-butyl-dithiocarbamic acidn-propylester-w-sodium sulfonate.
• a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid
• the method of cleansing the surface of metal objects which comprises contacting said objects with an aqueous solution of a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid, and from about 0.01 to about 0.5% by weight, based upon the weight of acid, of 2-mercaptobenzothiazole-S- propane-w-sodium sulfonate.
• a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid
• the method of cleansing the surface of metal objects which comprises contacting said objects with an aqueous solution of a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid, and from about 0.01 to about 0.5% by weight, based upon the weight of acid, of Z-mercaptobenzothiazole S-butanew-SOdillHl sulfonate.
• a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid
• the method of cleansing the surface of metal objects which comprises contacting said objects with an aqueous solution of an acid selected from the group consisting of sulfuric and hydrochloric acid which contains from about 0.01 to about 0.5 by weight based upon the weight of the acid, of at least one organic sulfonic acid component having a structural formula selected from the group consisting of:
• R is a bivalent alkyl radical having from I to 6 carbon atoms
• R is a radical selected from the group consisting of hydrogen, lower alkyl radicals having from 1 to 4 carbon atoms, and phenyl radicals and R -R represents two R groups joined to form a pentamethylene radical which together with the nitrogen atom form a piperidine radical
• composition for cleansing the surfaces of metal objects an aqueous solution of an acid selected from the group consisting of hydrochloric acid and sulfuric acid and from about 0.01 to about 0.5% by weight, of acid, of at least one inhibitor selected from the group consisting of organic sulfonic acids having a structural formula selected from the group consisting of:
• R is a bivalent alkyl radical having from 1 to 6 carbon atoms
• R is a radical selected from the group consisting of hydrogen, lower alkyl radicals having from 1 to 4 carbon atoms, and phenyl radicals and R -R represents two R groups joined to form a pentamethylene radical which together with the nitrogen atom form a piperidine radical
• the method of cleansing the surfaces of metal objects which comprises contacting said objects with an aqueous solution of a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid, and from about 0.01 to about 0.5% by weight based upon the weight of acid, of dithiocarbamic acid-n-propylesterw-sodium sulfonate.
• a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid
• the method of cleansing the surface of metal objects which comprises contacting said objects with an aqueous solution of a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid, and from about 0.01 to about 0.5% by weight based upon the weight of acid, of N,N-dimethyl-dithiocarbamic acid-n- 7 propylester-w-sodium sulfonate.
• a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid
• the method of cleansing the surface of metal objects which comprises contacting said objects with an aqueous solution of .a mineral acid selected .firom the group consisting of hydrochloric acid and sulfuric acid, and from about 0.01 to :abou.t0.5% by weight based upon the weight of acid, of N,N-d-iethyl-dithiocarbamic acid-npropylester-w-sodium sulfonate.
• the method of cleansing the surface of metal objects which comprises contacting said objects with an aqueous solution of a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid, and from about 0.01 to about 0.5% by weight based upon the weight of acid, of N,N-diisopropyl-dithiocarbamic acid-n-propyl-w-sodium sulfonate.
• a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid
• the method of cleansing the surface of metal objects which comprises contacting said objects with an aqueous solution of a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid, and from about 0;01 to aboutO.'5% by'weight based upon the weight of acid, of N,N-pentamethylene-dithiocarbamic acid-n-propylester-w-sodium sulfonate.
• a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid, and from about 0;01 to aboutO.'5% by'weight based upon the weight of acid, of N,N-pentamethylene-dithiocarbamic acid-n-propylester-w-sodium sulfonate.
• the method of cleansing the surface of metal objects which comprises contacting said objects with an aqueous solution of a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid, and from about 0.01 to about 0.5% by weight based upon the weight of acid, of trithiocarbonic acid-bis-n-propylester-w-sodium sulfonate.
• a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid
• the method of cleansing the surface of metal objects which comprises contacting said objects with an aqueous solution of a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid, and from about 0.01 to about 0.5% by weight based upon the weight of acid, of rhodanic acid-S-propane-w-sodium sulfonate.
• a mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid
• the method of cleansing the surface of metal objects which comprises contacting said objects with an aqueous solution of a mineral acid selected'from the group consisting of hydrochloric acid and sulfuric acid, and from about 0.01 to about 0.5% by weight based upon the Weight of .acid, of the .betaine salt of isothiourea-S- propane-w-sulfonic acid.
• a mineral acid selected'from the group consisting of hydrochloric acid and sulfuric acid

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
• Preventing Corrosion Or Incrustation Of Metals (AREA)

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Citations (12)

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  • BE BE532113D patent/BE532113A/xx unknown
• 1953
  • 1953-11-02 DE DED16268A patent/DE1034452B/de active Pending
• 1954
  • 1954-10-26 US US464888A patent/US2988512A/en not_active Expired - Lifetime
  • 1954-10-29 FR FR1111043D patent/FR1111043A/fr not_active Expired
  • 1954-11-01 CH CH335580D patent/CH335580A/de unknown
  • 1954-11-01 GB GB31438/54A patent/GB768581A/en not_active Expired

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