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 numberUS2502441 A
Publication typeGrant
Publication dateApr 4, 1950
Filing dateNov 22, 1946
Priority dateNov 22, 1946
Publication numberUS 2502441 A, US 2502441A, US-A-2502441, US2502441 A, US2502441A
InventorsRobert F Ayres, Sidney R Dodd
Original AssigneeOakite Prod Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Phosphate coating of metals
US 2502441 A
Abstract  available in
Images(3)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

Patented Apr. 4, 950

2,502,441 PHOSPHATE COATING F METALS Sidney R. Dodd, West Caldwell, N. J and Robert F. Ayres, New York, N. Y., assignors to Oakite Products, Inc, New York, N. Y., a corporation 1 .No Drawing. Application November 22, 1946,

Serial No. 711,810

1 The present invention relates to improvements ina composition and a process for depositing phosphate coating on metal surfaces when employed in phosphate coating solutions, and more particularly to compositions which will not only accelerate the deposition of a phosphate coating upon the surface of metals such as ferrous metals and other metals such as aluminum, zinc, magnesium and template, but also condition the coating obtained by improving the quality he o It is therefore an 'object'of the invention to provide a composition which, when added to a phosphate coating solution, will cause accelerated deposition of phosphate coatings on ferrous and other metal objects treated with such solution. It is another object to provide a composition which will, when added, to phosphate coating solutions, promote uniformity, hardness, and adherence of phosphate coatings obtained when treating metal objects with such solution.

It is a further object to provide an improved method of producing phosphate coatings on metal Larti'cles employing the novel phosphate coating solutions. V

A' proposal has already been made in German Patent No. 584,411 to add water soluble'molybdenum compounds to phosphating baths in order to provide accelerated deposition of a coating containing a mixture of phosphates and molybdenumoxides. However, it has been found that coatings produced from such baths containinga molybdenum compound tend to have poor adherence to the metal surface and have an undesirable soft or spongy nature rendering them inefficient as rust retarders and'of poor quality in forming a strong bond with paint, enamel and other organic finishes.

"In accordance with the present invention, it has been found that consistently uniform, adherent and hard phosphate coatings, which also have excellent corrosion resistant and paint bonding properties, may be obtained if the phosphating solution is employed to which a small quantity of a water soluble molybdenum or tungsten'compound suchfas the molybdic and tungsti'c acid compounds, molybdic acid, tungstic acid,:their anhydrides,v and their. .water soluble salts, and a small quantity of a phenolic substance, such as, for example, the tannins, tannin n'uclei,. and tannin derivatives have been added. I .The addition of such molybdenum or tungsten compound. in combination with a phenolic compound not only. accelerates and promotesthe Claims. (Cl. 148-615) production of a phosphate coating, but also pro-, duces desirable eifects in the quality and consistency of the coating obtained.

. It has also been found that phosphate coating solutions, in which the major ingredient is a primary phosphate of the alkali group, that is, the primary alkali metal or ammonium phosphates, will give good phosphate coatings when they contain a small quantity of the novel accelerating combination in accordance with the invention. In the absence of such accelerating combination little or no phosphate coating is obtained from solutions containing suchphosphates.

In addition, the use of the accelerating combination in accordance with the invention renders it possible to reduce the amount of free phosphoric acid usually present in solutions of which the major constituent is a monobasic phosphate of a heavy metal, such as zinc, manganese, or iron. In other words, phosphate coating solutions may be employed in accordance with the inventionat a higher pH than in usual practice, namely, at a pH of about 3.2 to about 5.5 instead of at about 2.5.

"Molybdenum compounds are preferably employed in accordance with the invention, but tungsten compounds possess similar properties. The following compounds are, for example, suitable: ammonium, sodium, potassium, molybdates and tungstates, and molybdic and tungstic' acids and acid anhydrides. The quantity of molybdenum or tungsten compounds employed in'a phosphate coating composition in accordance with the invention may range from 0.1% to 10% of the quantity of solid acid phosphate "saltpresent. Preferably, the quantity of such compounds used is between 0.5% and 2.0% as higher concentrations tend toward the production of softer coatings.

The phenolic ingredients of the novel composition in accordance with the invention are preferably tannins, phenolic tannin derivatives and related phenolics. However, other phenols,-

such as phenol itself, possess the desirable effect in the combinationin accordance with the in-' of other suitable phenolics are as follows:'

phenol, catechol, resorcinol, hydroq uinone, pyrogallol, pyrogallic acid, gallic acid, phloroglucinol and the like. The polyhydric phenolic com-- equal to the quantity of molybdenum or" tungsten compound used. However, the pro-..

portion may be varied within the limits of the quantities given above.

The phenolic compounds and molybdenum or tungsten compounds may be added separately or together to a phosphate coating solution or may be incorporated in a solid phosphating composition before preparation of the aqueous phosphate coating solution.

It is desirable to incorporate wetting or cleaning agents, which are effective in acid solution, to phosphate coating solutions prepared in accordance with the invention, but such wetting or cleaning agents may be omitted if the metal articles to be coated have been thoroughly cleaned before treatment with the solution.

The following wetting and cleaning agents are,

for example, suitable for use in phosphate coating compositions prepared in accordance with the invention:

Sulphonated fatty alcohols. Alkylated' aromatic sulphonates.

Complex sulphonated amides. Polyhydric alcohol anhydride ethers esterified 3 with fatty acids such as sorbitan monolaurate.

Non-ionic wetting agents such as polyethylene oxide derivatives of fatty alcohols or acids, or of other substances containing hydroxyl or carboxyl groups.

Any of these are suitable for use as the Wetting and cleaning agents which are recited in the examples given below, which will serve to illustrate the invention.

Example 1 A phosphate solution is prepared containing approximately 2 ounces per gallon of a composition of the following formula:

Per cent NaHzPOi 90.0 M003 1.0 Quebracho 0.5 Wetting and cleaning agent 8.51

This solution when used hot and applied for two minutes by pressure spraying to a ferrous metal surface will convert the surface into a prosphate coating averaging about 100 milligrams in weight per square foot of surface.

If the M003 and quebracho are omitted from the same type of acid phosphate solution, consistent deposition of a coating is diflicult to accomplish. Results are erratic; the coating being non-uniform, meagre, or completely non-existent.

If the molybdenum compound without the tannin is used in the same type of solution, a deposit results which seems amorphous in structure, is non-adherent to the surface, and of no value as a foundation for painting.

If the tannin is used Without the molybdenum compound in such solution, deposition .of a coat ing seemsto be completely inhibited. I

Example 2 An aqueous solution is prepared containing about 2 ounces per gallon of .the following composition:

Per cent NH4I-I2PO4 90.0 M003 1.0 Sumac tannin 1.0 Wetting and cleaning agents 8.0

This solution gives results similar to those obtained in Example 1 when used in the same manner.

Example 3 A phosphatingbath is prepared containing about 2'ounces per gallon of the following composition:

Per cent NaI-IzPO4 90.5 H3PO4 4.5 Ammonium molybdate 1.0 Catechol 1.0 Wetting and cleaning agents 3.0

Immersion of a steel article in such bath for 4 minutes at a temperature of 160 F. produces about milligrams of a 'hard continuous coating per square foot of surface.

Example 4 A phosphating bath is prepared containing about 2 ounces per gallon .of the following composition:

Per cent ZnH-;(PO4) 2 p 50.5 H3PO4.(75%) 47.5- MOO; 1.0 Quebracho 1.0

A steel panel immersed insuch bath for 4 minutes at 160 F. will receive a hard coating weighing about milligrams per square foot.

Example 5 A .phosphating solution containing 3 ounces per gallon of the following composition is prepared:

Per cent NaHaPOa. 91.9

H3PO4 4.5 Na2WO4.2I-I2O .6

Quebracho 1.0 Wetting and cleaning agents 3.0

This phosphating solution will produce about 85 milligrams of a hard, continuous, iridescent coating per square foot when used in the sam manner as the solution in Example 3.

Example 6 A phosphating solution containing '3 ounces per gallon of the following :composition is prepared:

' 1 Per cent NaH2PO4' 90.5 H3PO4 75 4.5 Ammonium molybdate 1.0 Resorcinol 1.0 Wetting and cleaning agents 3.0

This solution will produce results similar to those described in Example v3.

While the compositions given. in the .above examples in most instances include wetting and cleaning agents, they may be omitted and equal results will .be obtained if the metal articles are thoroughly .cleaned; bciorextreatment.

Also, while the phosphate coating solutions may be used in accordance with the invention at a pH between 3.2 and 5.5, it has been found preferable to adjust the pi-I value thereof to between 3.2 and 3.8 when the coating is obtained by tank immersion and to adjust the pH value thereof to 4.8 to 5.2 when a spray machine is used to apply the solution to the articles being coated.

We claim:

1. A phosphating composition comprising an acid salt of phosphoric acid and a water soluble compound selected from the group consisting of molybdic acid compounds and tungstic acid compounds and a phenol, said latter two ingredients each being present in a quantity ranging from 0.1% to of the quantity of acid salt of phosphoric acid.

2. A phosphating composition comprising an acid salt of phosphoric acid and a water soluble compound selected from the group consisting of molybdic acid compounds and tungstic acid compounds and a phenol, said latter two ingredients each being present in a quantity ranging from 0.5% to 2% of the quantity of acid salt of phosphoric acid.

3. A phosphating composition comprising an acid salt of phosphoric acid, a water soluble compound selected from the group consisting of 'molybdic acid compounds and tungstic acid compounds, and a polyhydric phenol, said latter two ingredients each being present in a quantity rang ing from 0.1% to 10% of the quantity of acid salt of phosphoric acid.

4. A phosphating composition comprising an acid salt of phosphoric acid, a water soluble compound selected from the group consisting of molybdic acid compounds and tungstic acid compounds, and a tannin containing at least one free phenolic hydroxy group, said latter two ingredients each being present in a quantity ranging from 0.1% to 10% of the quantity of acid salt of phosphoric acid.

5. A phosphating composition comprising an acid salt of phosphoric acid, a water soluble compound selected irom the group consisting of molybdic acid compounds and tungstic acid compounds, and quebracho, said latter two ingredients each being present in a quantity ranging from 0.1% to 10% of the quantity of acid salt of phosphoric acid.

6.1-1 phosphating composition comprising an acid salt of phosphoric acid, a water soluble molybdic acid compound and a phenol, said latter two ingredients each being present in a quantity ranging from 0.1% to 10% of the quantity of acid salt of phosphoric acid.

7. A phosphating composition comprising an acid salt of phosphoric acid, a water soluble molybdic acid compound and a polyhydric phenol, said latter two ingredients each being present in a quantity ranging from 0.1% to 10% of the quantity of acid salt of phosphoric acid.

8. A phosphating composition comprising an acid salt of phosphoric acid, a water soluble molybdic acid compound and a gallic acid, said latter two ingredients each being present in a quantity ranging from 0.1% to 10% of the quantity of acid salt of phosphoric acid.

9. A phosphating composition comprising an acid salt of phosphoric acid, a water soluble molybdic acid compound and a tannin containing at least one free phenolic group, said latter two ingredients each being present in a quantity ranging from 0.1% to 10% of the quantity of acid salt of phosphoric acid.

10. A phosphating composition comprising an acid salt of phosphoric acid, a water soluble molybdic acid compound and quebracho, said latter two ingredients each being present in a quantity ranging from 0.1% to 10% of the quantity of acid salt of phosphoric acid.

11. A phosphating composition comprising an acid salt of phosphoric acid, a water soluble molybdic acid compound and catechol, said latter two ingredients each being present in a quantity ranging from 0.1% to 10% of the quantity of acid salt of phosphoric acid.

12, A phosphating composition comprising an acid salt of phosphoric acid, a water soluble compound selected from the group consisting of mclybdic acid compounds and tungstic acid compounds, and a phenol, said latter two ingredients being present in substantially equal quantities, the quantity of each ranging from 0.1% to 10% of the quantity of acid salt of phosphoric acid.

13. A phosphating composition comprising a primary phosphate of the alkali group and a water soluble compound selected from the group consisting of molybdic acid compounds and tungstic acid compounds and a phenol, saidlatter two ingredients each being present in a. quantity ranging from 5.1% to 10% of the quantity of a primary phosphate of the alkali-group.

14. A phosphating composition comprising a primary phosphate of the alkali group, a water soluble molybdic acid compound and quebracho, said latter two ingredients each being present in a quantity ranging from 0.2% to 5% of the primary phosphate of the alkali group.

15. A process of coating metal surfaces which comprises contacting the metal surfaces with an aqueous solution of an acid salt of phosphoric acid containing a water soluble compound selected from the group consisting of molybdic acid compounds and tungstic acid compounds and. a phenol, said latter two ingredients each being present in a quantity ranging from 0.1% to 10% of the quantity of the acid salt of phosphoric acid.

SIDNEY R. DODD. ROBERT F. AYRES.

REFERENQES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,254,263 Oeschger Jan. 22, 1918 1,838,189 Tanner et a1 Nov. 15, 1932 1,893,495 Eberhard Jan. 10, 1933 1,911,537 Tanner May 30, 1933 1,946,647 Taylor et a1 Feb. 13, 1934 2,336,071 Clifford et a1 Dec. '7, 1943 2,375,468 Clifford et al May 8, 1945 2,385,800 Douty et a1 Oct. 2, 1945 FOREIGN PATENTS Number Country Date 584,411 Germany Sept. 20, 1933

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1254263 *Feb 21, 1917Jan 22, 1918Parker Rust Proof Company Of AmericaRust-proofing iron and steel surfaces.
US1888189 *Mar 29, 1932Nov 15, 1932Parker Rust Proof CoCoated metal article and method of and composition for producing said article
US1893495 *May 5, 1927Jan 10, 1933Rudolf EberhardProcess for making coating materials for deoxidation of rust
US1911537 *Jul 14, 1930May 30, 1933 Eobebt r
US1946647 *May 25, 1932Feb 13, 1934Eastman Kodak CoProcess of coating copper with cellulose acetate lacquer
US2336071 *Dec 13, 1941Dec 7, 1943Parker Rust Proof CoTreatment of metals
US2375468 *Dec 13, 1941May 8, 1945Parker Rust Proof CoPhosphate coating of metals
US2385800 *Feb 27, 1941Oct 2, 1945American Chem Paint CoPaint
DE584411C *Sep 23, 1931Sep 20, 1933Aladar Pacz DrVerfahren zur Herstellung von korrosionsfesten UEberzuegen auf Eisen und Stahl
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2657156 *Jul 21, 1949Oct 27, 1953Parker Rust Proof CoPhosphate coating composition and process
US2671995 *Oct 22, 1949Mar 16, 1954Colgate Palmolive CoPackaging of materials
US2681873 *Feb 25, 1954Jun 22, 1954Deniston George LProduction of black oxide films on aluminum
US2715059 *Aug 6, 1951Aug 9, 1955Kelite Products IncPhosphatizing composition
US2805969 *Dec 31, 1952Sep 10, 1957Parker Rust Proof CoMolybdenum accelerated solution and method for forming oxalate coatings on metallic surfaces
US2809906 *Nov 25, 1952Oct 15, 1957Wyandotte Chemicals CorpPhosphating compositions
US2854368 *Oct 31, 1956Sep 30, 1958Lionel Shreir LouisProtective coatings for metals
US2854369 *Oct 4, 1957Sep 30, 1958Oakite Prod IncIncreasing the solubility of metal accelerators in phosphatizing solutions
US2854370 *Oct 4, 1957Sep 30, 1958Oakite Prod IncComposition and method for phosphate coating of metal
US2927874 *Aug 14, 1958Mar 8, 1960Turco Products IncProcess for producing aluminum surface coatings
US3247791 *May 4, 1962Apr 26, 1966Litho Chemical And Supply Co ISurface treated lithographic plates and production thereof
US3272663 *Nov 13, 1962Sep 13, 1966Oakite Prod IncWash-primer coating including molybdate radical
US3411995 *Mar 15, 1965Nov 19, 1968EnthoneProcess and product for plating on cast,malleable,carburized and carbonitrided irons
US4017334 *Dec 15, 1975Apr 12, 1977Oxy Metal Industries CorporationProcess for treating aluminum cans
US4054466 *Feb 9, 1976Oct 18, 1977Oxy Metal Industries CorporationTannin treatment of aluminum
US4063969 *Feb 9, 1976Dec 20, 1977Oxy Metal Industries CorporationTreating aluminum with tannin and lithium
US4089708 *Apr 8, 1976May 16, 1978Compagnie Francaise De Produits IndustrielsPhosphatation of metallic surfaces
US4111722 *Feb 9, 1976Sep 5, 1978Oxy Metal Industries CorporationTannin treatment of aluminum with a fluoride cleaner
US4264378 *Feb 14, 1980Apr 28, 1981Oxy Metal Industries CorporationChromium-free surface treatment
US4293349 *Mar 17, 1980Oct 6, 1981Parker Italiana S.A.S.Protective compositions for steel surfaces and the process for their preparation
US4802972 *Feb 10, 1988Feb 7, 1989Phillips Petroleum CompanyHydrofining of oils
US4880478 *Dec 22, 1988Nov 14, 1989The United States Of America As Represented By The Secretary Of The ArmyProtective coating for steel surfaces and method of application
US5039363 *May 30, 1990Aug 13, 1991Nippon Paint Co., Ltd.Process for phosphating metal surfaces
US5221370 *Jun 14, 1990Jun 22, 1993Nippon Paint Co., Ltd.Method for forming zinc phosphate film on metal surface
US6027578 *Jun 9, 1998Feb 22, 2000Pavco, Inc.Non-chrome conversion coating
US6193815 *Jun 25, 1996Feb 27, 2001Henkel CorporationComposition and process for treating the surface of aluminiferous metals
US6902766Jul 27, 2000Jun 7, 2005Lord CorporationTwo-part aqueous metal protection treatment
DE1281774B *Jul 31, 1961Oct 31, 1968Agep Gnacke & Co Chem FabMittel zum Reinigen und Entfetten sowie Entlacken und Phosphatieren von Gegenstaenden aus Metallen
EP0880410A1 *Jan 15, 1997Dec 2, 1998Henkel CorporationPassivation composition and process for coating
WO2002010479A2Jul 23, 2001Feb 7, 2002Lord CorpTwo-part aqueous metal protection treatment
Classifications
U.S. Classification148/259
International ClassificationC23C22/42
Cooperative ClassificationC23C22/42
European ClassificationC23C22/42