Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS2276353 A
Publication typeGrant
Publication dateMar 17, 1942
Filing dateSep 28, 1935
Priority dateSep 28, 1935
Publication numberUS 2276353 A, US 2276353A, US-A-2276353, US2276353 A, US2276353A
InventorsJohn S Thompson
Original AssigneeParker Rust Proof Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Process of coating
US 2276353 A
Abstract  available in
Images(3)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

Patented Mar. 17, 1942 PROCESS F COATING .lolm S. Thompson, Detroit, Mich, assignor to harass Rust Proof (Jemuany, Detroit, Mich.

No Drawing. Application September 28, 1935, Serial No. 42,670. Renewed August 28, 1938 This invention relates to the field of the chemical coating of metals. An object of the invention is the rendering of metallic surfaces resistant to corrosion. A further object of the inven-- tion is to form on metallic surfaces a chemical coating which resists corrosion when coated with a paint, lacquer, or enamel and provides a base coat to which the applied coatings adhere in a much firmer manner than they would to the bare metal.

Generally speaking, the invention comprises the use of solutions containing soluble hydrofluosilicic compounds with the addition of an oxidizing agent with or without accelerating agents. Hydrofiuosillcic acid (HaSiFa) and soluble salts of this acid are comprised generally. oxidizing agents such as hydrogen peroxide may be employed and accelerating agents such as nitrates may be used.

By the use of these materials surfaces of metals such as iron, steel, aluminum and zinc and alloys are rendered rust resistant and in many cases coatings are formed which serve as a rust resisting base for paints, lacquers, enamels, and other coating compositions.

The process comprises generally treatment of the metal surface by any of the ordinary methods. .In the following examples which are given by way of illustration and not limitation the metallic surfaces were immersed in the solutions at a boiling }.temperature. The usual processing time was 5 minutes, although this may be decreased if desired. 'It is understood that the essential thing is to bring about a reaction between the surface of the metal and the solution and that the time, temperature, and other factors of operation may be varied considerably without departing from the scope of the invention. In the following examples 2" x 4" panels were employed in the usual case.

Example 1.--A sheet of aluminum was immersed in a 200 cc. solution to which had been added /2 gram chromic acid, 3 cc. HaSiFc. The metal was removed after 5 minutes at a boiling temperature and a hard, medium gray, very uni- ?form coating had been produced upon the surface "of the aluminum. When the same ingredients are used with the addition of 2 grams of sodium nit'rate, a brown coating is obtained which is liner .and softer.

Example 2.-The same conditions as in Example 1 were employed using a solution containing gram chromic acid and 5 grains manganese silicofluoride. A medium gray. very uniform, medium hard coating was obtained on the alumimm. when 2 grams of sodium nitrate is used with the other ingredients a harder, lighter, thinner coating is obtained.

Example 3.--Under the same conditions as in Example 1 a solution was employed containing V3 gram chromic acid, and 5 grams sodium silicofluoride. Th aluminum surface had a hard thin, light gray coating. When 2 grams of sodium nitrate is used with the other ingredients the same result is obtained.

Example 4.Under the same conditions as in Example 1 an aluminum sheet was treated with a solution containing 2 cc. of hydrogen peroxide and 3 cc. hydrofiuosilicic acid. Coatings were obtained which may be described as white, under a fairly hard gray surface. When 2 grams of sodium nitrate is employed with the other ingredients a medium gray, fairly hard coating is obtained.

Example 5.--Under the same conditions as in mample 1 an aluminum object is immersed in a solution to which has been added 1 gram potasslum permanganate and 3 cc. hydrofluosilicic acid.

A red-purple iridescent fairly hard coating is obtained. When 2 grams of sodium nitrate is used with the same ingredients 8 dark purple, soft and dusty coating is obtained.

Example 6.-Under the same conditions as in the preceding examples a solution was employed using 2 grams potassium dichromate and 5 cc. hy-

drofluosilicic acid. A rather soft gray coating is obtained on the aluminum. When 2 grams of sodium nitrate is used with the other ingredients 9. hard, brown coating is obtained.

Example 7.-Under the same conditions as in the preceding examples a solution is used containing 2 grams sodium chromate with 3 cc. hydrofluosiiicic acid. A dark gray, hard coating is obtained on the aluminum surface. When 2 grams of sodium nitrate is used together with the other ingredients a light brown, hard, thin coating is obtained.

Example 8.-Under the same conditions an aluminum surface is treated with a solution containing 2'grams chromium sulphat and 3 cc. hy-' drofluosilicic acid. There is obtained on the aluminum surface a soft green gray coating over a hard thin white. When 2 grams sodium nitrate is used together with the other ingredients, a thin,"

2 was taken. There was obtained on a steel surface a dark, gray, fairly hard coating.

Example lib-The solution employed was made up by adding 1 gram chromic acid, 2% cc. Basil;

and 2 grams sodium nitrate. A black, adherent coating .was obtained under a brown dust on a steel surface in 5 minutes.

Example 11.Under the same conditions as in the preceding examples a steel object was processed in a solution containing 2 grams chromlc acid, 5 grams manganese silicofluoride, 2% grams sodium nitrate for 1 to 5 minutes. There was obtained a black, adherent coating. The same results were obtained with the following ingredients in solution:

2 grams CrOa plus 5 gramsFeSiFa plus 2% grams N'aNOa 2 gr. Cr05+5 gr. FeSiFe+2 gr. MniNOa):

2 gr. Cra+3 cc. Fea(SiFs)s+2 gr. NaNO:

10 cc. H2SiFc+4 gr. KzCr0+2 gr. mason:

cc. HaSiFe+2 gr. KaCnO1+2 gr. ammo:

2 gr. Cr:(SO4)a+5 cc. HaSiFs+2 gr. NaNOl Example 12.--Under the same conditions as in the preceding examples a steel object was proc-' essed in a solution containing 1 cc. HsSiFs+3 gr. K1804 for 5 minutes. vA like solution with 2 gr. NaNO: added gave the same rust proofing results as tested in the salt spray, both being an improvement over non-treated. steel.

Example 13.-Other salts that may be substituted for K2804 in the combinations given in the example Just above are:

NaCl NaaSOs NaHzPOs NaHaPOs NMMOOQ KClO: NMWOs N82340:

HCl HNO:

HsPO4 H280:

HsPOa H010:

HClQ4 Boric acid Molybdio acid Tungstic acid Slight variations in proportions may be necessary in the chemicals used in these examples, but added corrosion resistance is. obtained from all of them.

Example 16.-Under the same conditions as in the preceding examples a steel object was processed in a solution containing 2 co.HaSiFs+l cc.

30% H202. A soft brown and black coating re sulted in 5 minutes. Alike solution containing 1 cc. HzSiFs+1 cc. 30% H202+2 gr. NaNO: produced a very uniform, adherent, light gray coating in 5 minutes. Both of these treatments gave exceptionally good salt spray test results.

Example 17.Under the same conditions as in the preceding examples a steel object was processed in a solution containing 2 cc. HaSiFs and suited in 5 minutes which was adherent under a loose top dust.

Example 18.Underthe same conditions as in the preceding examples a steel object was processed in a solution containing 1 cc. HaSiFs+2 gr. KaSzOa. A thin-iridescent coating resulted in 5 minutes but the addition of 2 grams NaNOl to this solution produced a dark gray coating.

Example 19.Under the same conditions as the preceding examples a steel object was processed in a solution containing 6 gr. NaIhPO4+6 gr. MnSiFs+4 gr. Mn(NO:)z and a gray adherent coating resulted in 15 minutes at boiling temperature. Manganese dihydrogen phosphate may be substituted for the sodium phosphate in this example and FeSiFs or ZllSiFs may be substituted for the MnSiF'o.

Example 20..Under the same conditions as in the preceding examples a steel object was processed in a solution containing 2 /2 cc. HzSiFs and 2 gr. NaNOs. A very uniform soft gray coating resulted in 5 minutes. 5 gr. MllSiFs may be substituted for the H1811"; in this combination and very good corrosion resistance is shown from both treatments.

Example 21.-A 200 cc. solution containing 5 gr. MnSiFa+.2 cc. 85% 8.1904 produced a good coating in 5 minutes. The addition of 2 grams NaNOl to this solution also produced a resistant 1 gr. KMnOa A gray and brown coating recoating in 5 minutes. In this example FeSiFs may be substituted for MnSiFs and Mn(NOa)z may be substituted for the NaNOa.

In thefollowing examples objects with a zinc surface were immersed in a boiling solution for 5 minutes.

Example 22.-1 gram CrO: plus 2 cc. HzSiFs.

A thin gray, fairly hard coating was obtained. When 2 grams of sodium nitrate is used with the other ingredients a coating is obtained which is gray with green tint, fairly hard and uniform. In this example if sodium nitrate is replaced by manganese nitrate or zinc nitrate similar results are obtained. When aluminum nitrate is employed in place of the sodium nitrate a coating is obtained which is hard, adherent and heavy gray.

Example 23.-2 grams chromium sulphate plus 2 cc. HzSiFs. When 2 grams of sodium nitrate is used with the other ingredients a uniform, dark, dull, hard, adherent coating was obtained.

Example 24.1 gram CrO: plus 1 gram KMnOr plus 2 cc. HaSiFa. A hard gray coating under a soft purple one is obtained. When 2 grams of sodium nitrate is used with the other ingredients similar results are obtained.

Example 25.1 gram CrO: plus 5 grams MnSiFs, A coating is obtained similar to that when using HaSiFs in place of MIlSiFs. When 2 grams sodium nitrate is employed with the other ingredients a green coating is obtained.

Example 26.--2 cc. HaSiFs plus 2 grams sodium nitrate. A transparent, fairly hard, dark gray coating is obtained. When zinc nitrate is .used in place of sodium nitrate, similar results are obtained. Example 27.--1 gram chromic acid plus 1 gram of K2820: plus 1 cc. mSiFa. A hard gray mixed dark and light coating is obtained. When 2 grams sodium nitrate are'used with the other ingredients a soft, dark green shiny finish is obtained. 1

In the above examples metals other than those specifically mentioned can be processed. Time, temperatures, proportions and ingredients can be varied well within the scope of the invention, the essence being the treatment of metals with solutions containing the SiFc radical together with the use of oxidizing agents with or without accelerating agents.

The examples mentioned above include hydrogen-peroxide, nitric acid and nitrates, chromic acid, chromates and dichromates, permanganates, sulphurous acid and sulphites, chloric and perchloric acids and chlorates, molybdates, tungstates, and persulphates, which are recognized oxidizing agents, and other compatible oxidizing agents may be used. The oxidizing agent must, of course, be a compatible material, that is, it must be soluble in the solution and its oxidizing power must not be destroyed by the other ingredients in the solution before it has an opportunity to exert its oxidizing power in the chemical reaction that takes place at the surface of the work.

It has been found that acceleration is gained by adding to these solutions a soluble salt of a metal below the respective metal being treated in the electromotive series. This acceleration is apparent in quickening of processing time, more uniformity in the coating and in producing aheavier coating. In the case of treating an iron surface, salts of metals slightly above iron in the electromotive series may be used.

What I claim is:

1. A process of treating a surface of a metal included in the group consisting of iron, steel, zinc, aluminum and their alloys, which comprises subjecting said surfaces to the action of a heated solution containing the SiFe radical and one of the group consisting of chromic acid and nitric acid, and treating the metallic surface until a visible protective paint-holding coating is obtained thereon and then applying a coating of one of the group consisting of paints, lacquers and enamels.

2. A process'of treating a surface of a metal included in the group consisting of iron, steel, zinc,'aluminum and their alloys, which comprises subjecting said surfaces to the action of a heated solution containing a soluble hexavalent chromium compound and one of the group of HzSiFs and soluble salts thereof, at least one of the aforesaid being added in the form of acid and continuing such action until a visible protective paint-holding coating is obtained upon the metallie surface and thereafter applying a coating of one of the group consisting of paints, lacquers and enamels.

3. A process of treating a surface of a metal included in the group consisting of iron, steel, zinc, aluminum and their alloys, which comprises subjecting said surfaces to the action 'of a heated solution containing chromic acid and one of the group of HzSiFa and soluble salts thereof, and continuing such action until a visible protective paint-holding coating is obtained upon the metallic surface and thereafter applying a coating of one of the group consisting of paints, lacquers and enamels.

4. A process which comprises treating a surface of a metal included in the group consisting of iron, steel, zinc, aluminum and their alloys with a heated solution containing the radical SiFc and nitric acid, and continuing such treatment until a visible, protective paint-holding coating is obtained upon the metallic surface and thereafter coating the surface with one of the group consisting of paints, lacquers and enamels.

5- A process of treating a surface of.a metal included in the group consisting of iron, steel,

zinc, aluminum and their alloys, which comprises subjecting said surfaces to the action of an aciduated heated solution containing as its chief active ingredients the SiFs radical and a compatible oxidizing agent, and treating the metallic surface until a visible protective paint-holding coating is obtained and thereafter applying to the metal surfacea coating of one of the group consisting of paints, lacquers and enamels.

6. A process of treating a surface of a metal included in the group consisting of iron, steel, zinc, aluminum and their alloys, which comprises subjecting said surfaces to the action of an acidulated heated solution containing as its chief active ingredients the SiFs radical and a compatible oxidizing agent of the group consisting paints, lacquers and enamels.

JOHN S. THOMPSON.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2434237 *Sep 13, 1943Jan 6, 1948Sk Wellman CoApparatus for applying powdered metal briquets to curved metallic surfaces
US2434525 *Aug 23, 1943Jan 13, 1948Rheem Mfg CoCoating on metals
US2454799 *Dec 9, 1944Nov 30, 1948David HartMethod of producing protective coatings on magnesium powder
US2497905 *Mar 3, 1945Feb 21, 1950Rheem Mfg CoCoating zinc or cadmium to impart corrosion and abrasion resistance
US2500672 *Jun 8, 1949Mar 14, 1950Socony Vacuum Oil Co IncSynthetic lubricants
US2501349 *May 10, 1946Mar 21, 1950Westinghouse Electric CorpInsulation for magnetic material
US2507956 *Nov 1, 1947May 16, 1950Lithographic Technical FoundatProcess of coating aluminum
US2520475 *May 29, 1947Aug 29, 1950Carlo SonninoProcess for the chemical oxidation of aluminum and alloys thereof
US2522474 *Jul 2, 1942Sep 12, 1950Battelle Memorial InstituteTreatment of zinc surfaces
US2559878 *Dec 29, 1948Jul 10, 1951Western Electric CoZinc and cadmium passivating bath
US2591479 *May 12, 1947Apr 1, 1952Parker Rust Proof CoMethod of and solution for coating surfaces chiefly of zinc
US2681873 *Feb 25, 1954Jun 22, 1954Deniston George LProduction of black oxide films on aluminum
US2762731 *Mar 29, 1952Sep 11, 1956American Chem Paint CoMethod of and materials for producing paint bonding films on ferriferous metal surfaces
US2786002 *Apr 28, 1954Mar 19, 1957American Chem Paint CoMethod of treating zinciferous surfaces
US2795518 *Apr 14, 1954Jun 11, 1957American Chem Paint CoProcess for treating steel, zinc, and aluminum to increase corrosion resistance
US2796370 *Mar 4, 1955Jun 18, 1957Ostrander Charles WComposition and method for producing corrosion resistant protective coating on aluminum and aluminum alloys
US2796371 *Mar 16, 1955Jun 18, 1957Allied Res Products IncCorrosion resistant protective coating on aluminum and aluminum alloys
US2798830 *Aug 4, 1953Jul 9, 1957American Chem Paint CoMethod of improving the corrosion resistance of certain coated aluminum surfaces
US2819192 *Dec 23, 1955Jan 7, 1958Du PontModification of aluminum surfaces
US2843513 *Jul 28, 1954Jul 15, 1958Allied Res Products IncMixture and method for imparting a corrosion-resistant surface to aluminum, aluminumalloys, and silver
US2851385 *Apr 3, 1952Sep 9, 1958Amchem ProdProcess and composition for coating aluminum surfaces
US2851386 *May 5, 1954Sep 9, 1958Allied Res Products IncMethod for coating zinc and zinc alloy sheets
US2864732 *Oct 5, 1953Dec 16, 1958Battelle Development CorpMethod of coating titanium articles and product thereof
US2884350 *Dec 28, 1955Apr 28, 1959Sylvania Electric ProdSolderable zinc alloy coating
US2926125 *Oct 22, 1956Feb 23, 1960Canadian IndCoating articles of magnesium or magnesium base alloys
US3018211 *Jan 26, 1959Jan 23, 1962Purex Corp LtdComposition and process for brightening aluminum and its alloys
US3130085 *Jun 4, 1963Apr 21, 1964Amchem ProdMethod and materials for applying chromate conversion coatings on zinciferous surfaces
US3130086 *Jul 22, 1963Apr 21, 1964Amchem ProdMaterials and method for use in applying chromate conversion coatings on zinciferous surfaces
US3347713 *Feb 3, 1964Oct 17, 1967Hooker Chemical CorpProcess for forming chromate coatings on aluminum
US3404046 *Sep 25, 1964Oct 1, 1968Hooker Chemical CorpChromating of zinc and aluminum and composition therefor
US3539402 *Nov 20, 1967Nov 10, 1970Collardin Gmbh GerhardSolutions for the deposition of protective surface layers on iron and zinc and process therefor
US3539403 *Nov 20, 1967Nov 10, 1970Collardin Gmbh GerhardSolutions for the deposition of protective layers on zinc surfaces and process therefor
US3816142 *May 8, 1972Jun 11, 1974Lindemann KElectroless chromium plating process and composition
US3876435 *Oct 1, 1973Apr 8, 1975Amchem ProdChromate conversion coating solutions having chloride, sulfate, and nitrate anions
US3982951 *Apr 20, 1973Sep 28, 1976Stauffer Chemical CompanyAluminum chromate protective coatings for aluminum
US4414039 *Nov 18, 1981Nov 8, 1983Motoren-Und Turbinen-Union Munchen GmbhMethod of activating titanium surfaces
US4551434 *Feb 22, 1984Nov 5, 1985Mtu Motoren-Und Turbinen-Union Muenchen GmbhMethod for recognizing structural inhomogeneities in titanium alloy test samples including welded samples
US4711667 *Sep 18, 1986Dec 8, 1987Sanchem, Inc.Corrosion resistant aluminum coating
US4895608 *Apr 29, 1988Jan 23, 1990Sanchem, Inc.Corrosion resistant aluminum coating composition
US5123978 *Mar 19, 1991Jun 23, 1992The United States Of America As Represented By The Secretary Of The NavyCorrosion resistant chromate conversion coatings for heat-treated aluminum alloys
US5707465 *Oct 24, 1996Jan 13, 1998Sanchem, Inc.Low temperature corrosion resistant aluminum and aluminum coating composition
US5769967 *Jul 2, 1996Jun 23, 1998Henkel CorporationComposition and process for treating metal
US8810190Sep 10, 2008Aug 19, 2014The Powerwise Group, Inc.Motor controller system and method for maximizing energy savings
DE975498C *Jun 27, 1952Dec 14, 1961American Chem Paint CoVerfahren zur Erhoehung der Haftfaehigkeit und Lebensdauer von organischen UEberzuegen, z. B. von Farbe, Lack u. dgl. auf korrosionsfaehigen Metalloberflaechen und Loesung bzw. Konzentrat zur Durchfuehrung des Verfahrens
DE976375C *Jun 19, 1953Jul 25, 1963Amchem ProdVerfahren zur Erhoehung der Korrosionsfestigkeit von Oberflaechen aus Aluminium und dessen Legierungen
DE977586C *Dec 11, 1952Jun 8, 1967Amchem ProdVerfahren zur Erzeugung von UEberzuegen auf Aluminium und dessen Legierungen
DE2031358A1 *Jun 25, 1970Dec 30, 1971Collardin Gmbh GerhardProtective coatings on iron, zinc or aluminium - formed by treatment with acid solns contg complex fluorides, free fluorine
EP1552035A1 *Apr 25, 2003Jul 13, 2005Henkel Kommanditgesellschaft auf AktienPickling or brightening/passivating solution and process for steel and stainless steel
Classifications
U.S. Classification148/268, 148/273
International ClassificationC23C22/37, B05D3/10, C23C22/34
Cooperative ClassificationB05D3/10, C23C22/34, C23C22/37
European ClassificationB05D3/10, C23C22/37, C23C22/34