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
  • C23G5/00—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
  • C23G5/02—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents
  • C23G5/032—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents containing oxygen-containing compounds

Definitions

• the present invention relates to methods and compositions for pickling metals, that is to say removing superficial impurities, including oxides, from the surface of said metals.
• the object of the present invention is to provide a pickling method and composition of matter which obviates these drawbacks.
• the pickling liquid to the desired composition. This results from the fact that the aqueous liquid resulting from this separation can be decanted without difliculty, and, g as its volume is proportional to the consumption of active-product, it will sufllce, in order to regenerate the pickling liquid, to replace the decanted portion by a substantially equal volume of a suitable regenerating liquid, containing a suit- 10 able percentage of the consumed products.
• the pickling liquid necessary to the'application of the method thus defined may be given various compositions and it may be used either in the cold or in the hot state.
• this liquid of alcohols or of phenols or of saturated w or unsaturated aliphatic acids or hydrocarbons or mixtures of the same, either in the presence of glycerides or not, and of one or several stronger acids capable of dissolving in these alcohols or these phenols, such as hydrochloric acid, acetic acid, phosphoric acid, formic acid, lactic acid, oxalic acid, etc.
• alcohols we may employ, either alone or in, I mixture, methyl, ethyl, amyl, butyl alcohols and I their higher homologues, and also glycols and f their etherlfled and esterifled derivatives, these alcohols or glycols containing, or not, a small amount of trioxymethylene. We may also make use of industrial mixtures of alcohols.
• fatty acids we may make use of undecylenic acid, oleic, stearic acids, and the like.
• the metallic oxides of the surface to be pickled combine with the strong acids, yielding metallic compounds in an aqueous medium which possess the property of separating spontaneously by difference of density of the fatty medium in which they are formed.
• a steel sheet covered with FeaOi oxide either rusted or not
• this sheet is immersed into a mixture containing: one part and a half of undecylenic acid, one part and a half of hydrochloric acid, and seven parts of butanol, by heating to a temperature of about 80 C., the proportions above indicated being given in volumes.
• the metal sheet after treatment, is perfectly capable of receiving a fatty varnish, either in the cold state, or in an oven, or of being protected or welded in any suitable manner in an anhydrous medium.
• the proportions of undecylenic acid and of the other acids soluble in the alcohols may vary, saine as those of the solvents.
• the pickling mixture should attack only the oxides, without exerting any action on the metal proper, according to the invention, we dissolve in the hot state in said pickling mixture a small amount of trionmethylene, for instance from 3 per thousand to 3 per cent, and the pieces to be pickled are heated only to a temperature of 60 C.
• trionmethylene produces esters which are attacked by the metallic oxides, with regeneration of the trioxymethylene and formation of metallic salts. while of course the pure metal is notcapable of attacking said esters.
• this product may be employed by atomizing, coating, or again, mixed with an inert powdery product, in the form of a paste which may adhere for the desired time on the surfaces to be pickled.
• this product may be employed by atomizing, coating, or again, mixed with an inert powdery product, in the form of a paste which may adhere for the desired time on the surfaces to be pickled.
• regeneration of the product will not be possible, but the spontaneous separation of the products of the reaction will have for its eifect to create a kind of local circulation in' all points of the surface, which circulation increases the emciency of the pickling acids.
• a method for removing superficial impurities from metals which comprises contacting said metals with a liquid water-repellent pickling composition which is a non-solvent for pickling residues and has a lower specific gravity than water.
• a method for removing superficial impurities from metals which comprises contacting .said
• a water-repellent pickling composition including hydrochloric acid, undecylenic acid and butanol.
• a water-repellent pickling composition which includes a pickling acid selected from the group consisting of hydrochloric acid, acetic acid, phosphoric acid, formic acid, lactic acid and oxalic acid, a higher aliphatic acid, an alcohol which is substantially immiscible with water, and a small proportion of trioxymethylene.
• a water-repellent pickling composition including about 1.5 parts by volume of undecylenic acid, 1.5 parts by volume of hydrochloric acid and 7 parts by volume of butanol.
• a water-repellent pickling composition which includes a pickling acid selected from the group consisting of hydrochloric acid, acetic acid, phosphoric acid, formic acid, lactic acid and oxalic acid, a higher aliphatic acid and a liquid phenol substantially immiscible with water.
• a method for removing impurities from metal surfaces which comprises subjecting the surfaces to the action of a water-repellent pickling composition including an acid pickling agent selected from the group consisting of hydrochloric acid, acetic acid, phosphoric acid, formic acid, lactic acid and oxalic acid, a higher aliphatic acid and a liquid phenol substantially immiscible with 20 water.
• a water-repellent pickling composition including an acid pickling agent selected from the group consisting of hydrochloric acid, acetic acid, phosphoric acid, formic acid, lactic acid and oxalic acid, a higher aliphatic acid and a liquid phenol substantially immiscible with 20 water.

Landscapes

• 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)
• Detergent Compositions (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=9047566

Family Applications (1)

Country Status (5)

Cited By (7)

Families Citing this family (2)

• 0
  • BE BE418799D patent/BE418799A/xx unknown
• 1935
  • 1935-12-10 FR FR810719D patent/FR810719A/fr not_active Expired
• 1936
  • 1936-03-28 FR FR47895D patent/FR47895E/fr not_active Expired
  • 1936-12-08 US US114871A patent/US2152406A/en not_active Expired - Lifetime
  • 1936-12-10 DE DE1936D0074111 patent/DE698197C/de not_active Expired
  • 1936-12-10 GB GB34000/36A patent/GB488656A/en not_active Expired

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