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
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/02—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using non-aqueous solutions
  • C23C22/04—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using non-aqueous solutions containing hexavalent chromium compounds
• • 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
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/82—After-treatment
  • C23C22/83—Chemical after-treatment

Definitions

• the present invention relates to a method and material for cleaning and coating surfaces of metals such as iron, aluminum, zinc, steel, stainless steel, or the alloys of iron, aluminum and zinc, or metallic surfaces having a preliminarily formed chemical coating thereon. More particularly, this invention relates to an improved material which simultaneously cleans and produces a sub stantially integral coating on a metallic surface or a chemically coated metallic surface, to thereby render the surface more receptive to paint or the like.
• metals such as iron, aluminum, zinc, steel, stainless steel, or the alloys of iron, aluminum and zinc, or metallic surfaces having a preliminarily formed chemical coating thereon. More particularly, this invention relates to an improved material which simultaneously cleans and produces a sub stantially integral coating on a metallic surface or a chemically coated metallic surface, to thereby render the surface more receptive to paint or the like.
• Another object of this invention is to provide a method for applying a combined cleaning and coating solution to the surface of metals or chemically coated metals.
• the aforementioned objectives may be accomplished by applying a solution comprising tertiary butyl alcohol, chromic acid and hydrocarbon solvent to 'the surfaces of the heretofore mentioned metals or chemically coated metals.
• 'lllgggopggf usefulness of this solution may be increased by adding thereto a controlled r gsion and human finge prints from the surface of the metal so treated and depositing thereon, a thin, uniform 2,762,732 Patented Sept.
• chromic acid known to be a strong oxidizing agent, must be compatible with the other constituents in the solutions, so that it will not be reduced prior to the time of application to the surface to be treated. It is furthermore desirable that the solution contain a blending agent capable of mutually dissolving water and the hydrocarbon solvent thereby rendering chromic acid and water compatible with the hydrocarbon solvent or solvents.
• tertiary butyl alcohol has been found to be particularly well suited.
• composition of this invention may have the following proportions of ingredients:
• Tertiary butyl alcohol 40-90 parts by volume. Hydrocarbon solvent 10-60 parts by volume. Water 0 to saturation.
• chromic acid should be added in proportion to produce .025% to 10% chromic acid by weight of the total weight of the formulation. Additionally, it has been found, that water may be present in excess of saturation, and in proportions equal to and exceeding the total volume of hydrocarbon solvent and tertiary butyl alcohol when a dispersion is formed of the water and organic solvents.
• the hydrocarbon solvent and the tertiary butyl alcohol are preferably combined, within the stated limits, to form a total of parts by volume.
• hydrocarbon solvent which is capable of dissolving grease, oil, or the like and having a boiling range extending from about 50 C. to about 270 C.
• hydrocarbon solvent which is capable of dissolving grease, oil, or the like and having a boiling range extending from about 50 C. to about 270 C.
• any solvent encompassed by the term hydrocarbon solvent which is capable of dissolving grease, oil, or the like and having a boiling range extending from about 50 C. to about 270 C.
• any solvent encompassed by the term hydrocarbon solvent which is capable of dissolving grease, oil, or the like and having a boiling range extending from about 50 C. to about 270 C.
• the solutions of this invention may be applied to metallic surfaces or chemically treated nonmetallic surfaces by spraying, wiping, brushing or dipping.
• Most beneficial resistance to subsequent blistering and peeling has been found to result when the deposited film of hexavalent chromium on the treated surface has a weight of between about .003 milligram per square foot to about mgs. per square foot, and even better results are obtained when the coating weight falls within the range of about 1 to 4 mgs. per square foot. It will be clear that the optimum concentration of chromic acid in the solution will vary with the method of application to the surface.
• the concentration of chromic acid should be substantially lower than in solutions which are to be applied by wiping, since the wiping action tends to remove the greater proportion of the applied chromic acid.
• the excgss sglutign is allowed to drain off and the residual film is formed on the sur ace y rying either in air or in tem eratures betwee s and undesirable quantities of hexavalent chromium may remain on the surface if the concentration of chromic acid is too high in the solution which is applied, for example, concentrations exceeding about 4% by weight of the solution.
• concentration of chromic acid may not, therefore, be predetermined with certainty, it is apparent that the desired concentration may be determined by a few routine tests under actual operating conditions. The same considerations will be seen to apply also in the case of applying the solution to the surface by dipping.
• paint is intended in its broad sense to include varnishes, lacquers, enamels and coating materials always referred to as paints.
• the water is added in this formulation somewhat close to the time of intended use.
• the other portions of the formulation form a stable trans- Example 2
• Heavy naptha mineral spirits having a boiling range between about 155 C. and 195 C. and a specific
• the proportions of heavy naphtha and tertiary butyl alcohol were varied in approximately 10 ml. intervals throughout the range of 40 to 90 ml. of tertiary butyl alcohol, and 10 to 60 ml. of heavy naphtha.
• the sum of the two ingredients always equalled 100 ml., and the water was varied from 0 to about 30 ml., which approximated saturation at parts tertiary butyl alcohol, and 10 parts heavy naphtha.
• the chromic acid was varied to produce compositions having a chromic acid content from .025 up to approximately 10%.
• a plurality of panels were treated in accordance with the procedure set forth under Table 1, and comparable results were obtained in all cases.
• Example 3 The heavy naphtha of Example 3 was substituted for by a number of other hydrocarbon solvents including toluene, xylene, gum turpentine and kerosene.
• hydrocarbon solvents including toluene, xylene, gum turpentine and kerosene.
• grease, oil, finger prints or metallic oxides which comprises applying to the said surface, a solution containing as essential ingredients 40 to 90 parts by volume tertiary butyl alcohol, to 60 parts by volume of a hydrocarbon solvent, up to 30 parts by volume water, and .025 to 10% chromic acid by weight of the total weight of the solution and drying a film of said solution upon the surface.
• a method of treating the surface of a metal of the class consisting of iron, aluminum and zinc and the alloys thereof, and chemically coated metallic surfaces which comprises applying to the said surface, a dispersion containing as essential ingredients 40 to 90 parts by volume tertiary butyl alcohol, 10 to 60 parts by volume of a hydrocarbon solvent, .025 to 10% chromic acid by weight of the combined weight of tertiary butyl alcohol and hydrocarbon solvent and a proportion of water in excess of that which is soluble in the solution of tertiary butyl alcohol, hydrocarbon solvent and chromic acid, and drying a film of the said dispersion upon the surface.
• a method in accordance with claim 1, wherein the film dried upon the surface has a weight between about .003 mg. per square foot and about 10 mgs. per square foot.
• weight of the film on the said surface is between about .003 mg. per square foot and about 10 mgs. per square foot.
• a method of treating the surface of a metal of the class consisting of iron, aluminum and zinc and the alloys thereof, and chemically coated metallic surfaces which comprises applying to the said surface a solution containing as essential ingredients tertiary butyl alcohol, a hydrocarbon solvent, and chromic acid, said alcohol being present in an amount of about 40 parts to 90 parts by volume, said solvent being present in an amount of about 10 parts to 60 parts by volume and said chromic acid being present in an amount of about .25% to 10% by weight of the total weight of the solution.
• a composition of matter for preparing surfaces of the class consisting of metals and chemically coated metals for receiving a siccative coating consisting essentially of to 90 parts by volume tertiary butyl alcohol, 10 to parts by volume of a hydrocarbon solvent, and .025% to 10% chromic acid by weight of the total solution.
• a composition of matter for preparing surfaces of the class consisting of metals and chemically coated metals for receiving a siccative coating consisting essentially of 40 to parts by volume tertiary butyl alcohol, 10 to 60 parts by a volume of a hydrocarbon solvent, up to 30 parts by volume water, and .025% to 10% chromic acid by weight of the total solution.
• a composition of matter for preparing surfaces of the class consisting of metals and chemically coated metals for receiving a siccative coating consisting essentially of 40 to 90 parts by volume tertiary butyl alcohol, 10 to 60 parts by volume of a hydrocarbon solvent, 0.025 %10% chromic acid by weight of the combined weight of tertiary butyl alcohol and hydrocarbon solvent and water in excess of the amount which is soluble in the solution consisting of tertiary butyl alcohol, hydrocarbon solvent and chromic acid.

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• Chemical & Material Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Chemical Treatment Of Metals (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

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Family Applications (1)

Country Status (3)

Cited By (8)

Citations (5)

Family Cites Families (3)

• 1951
  • 1951-11-19 US US257201A patent/US2762732A/en not_active Expired - Lifetime
• 1952
  • 1952-03-31 FR FR1059896D patent/FR1059896A/fr not_active Expired
  • 1952-04-19 DE DEP7500A patent/DE1062085B/de active Pending

Patent Citations (5)

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