US2075757A

US2075757A - Metal treatment

Info

Publication number: US2075757A
Application number: US88066A
Authority: US
Inventors: Conquest Victor
Original assignee: Armour and Co
Current assignee: Armour and Co
Priority date: 1936-06-29
Filing date: 1936-06-29
Publication date: 1937-03-30
Anticipated expiration: 1954-03-30

Description

Patented Mar. 30, 1937 METAL TREATMENT Victor Conquest, Chicago, Ill.', assignor to Armour and Company, Chicago, 111., a corporation of Illinois No Drawing. Application "June 29, 1936,

Serial 20 Claims. (Cl. 91-68) This invention relates to the treatment of metal surfaces to provide them with a corrosion-resisting film and it comprises, as new products, metal articles carrying a corrosionresisting film composed of a ketone having the general formula R-C-R' wherein R is a'closed ring radical and R is an aryl radical containing at least six carbon atoms; it further comprises processes wherein metal surfaces subject to atmospheric corrosion are coated with such ketones.

Various methods of providing'metal surfaces such as steel with corrosion-resisting coatings have been proposed in the prior'art. For example, steel has been treated with many different chemical reagents to so modify the steel surface that an anti-rusting surface is presented to the forces of atmospheric corrosion. Such metal treatment results in the deposition on the surface of an extremely thin film which is not attacked by atmospheric moisture, oxygen, and

' similar substances ordinarily tending to rust the steel. All of these so-called metal treatmentsare essentially surface reactions. They are not to be confused with painting or otherwise applying protecting coatings which do not actually modify the surface of the metal itself. Paints and like coating compounds merely form a coating on the surface. Should the paint chip oil, the exposed metal surface rusts or corrodes readily. These metal treating processes are of great utility in the pre-treatment of metal surfaces prior to the application of ornamental paint films. For example, it is customary to rustproof steel automobile bodies before the application of lacquers thereto. This is to protect the 4 metal surface in the event some of the lacquer film is chipped or scratched oil. I have now. discovered that so-called mixed ketones, that is, ketones wherein one of the radicals attached to the carbonyl group is a 45 closed ring radical such as phenyl, and the other I adical lsan alkyl radical containing at least six arbon atoms,- will. form adsorbed molecular films on metal surfaces normally corroding or rusting in the atmosphere, that such films are- 0 substantially permanent, and that such films protect the metal surface against corrosion; These films aremot, however, to be confused with coatings such as lacquers. Apparently metal surfaces treatedwith the ketones of'my invention 55 actually unite with the ketone in some way.

, dicted.

toward atmospheric especially useful in the practice of myinvention.

can be demonstrated quite readily. When steelarticles, such as automobile fenders, are immersed in, or, spraye'd'with a liquid mixture of ketones of the class embraced within my invention, and the surface then drained to remove excess ketone so that the surface is apparently free of any extraneous material, the metal'is highly anti-corrosive. In fact when the treated metal surfaces are actually subjected to the actio-n of good solvents for the ketone films thereon, the

film cannot be removed. This indicates to me that the metal surface has adsorbed a thin film,

probably of molecular dimensions. Adsorption phenomena of this type are in the realmof surface chemistry and cannot, of course, be pre- That. the metal surface will adsorb molecular films of these ketones is surprising although the adsorption of gas, liquids and solids by surfaces is, of course, a recognized physicalchemical phenomenon.

The ketones which I use. to protect the metal against corrosion are all highly stable substances chemically. They are. insoluble in water and are not oxidized by ainmoisture, light; or carbon dioxide and similar acidic compounds normally present in the atmosphere. Their inertness influences. makes them P T-Eur o n Moreover, they are relatively inexpensive since Y they can be prepared from the cheap fatty. acids available in large quantities. H

When practising my invention all that is necessary is to cause the metal surface to contact with the ketone in any suitable manner. As will be pointed out in detail present1y,,all of the ketones used inmy invention are either liquids orwaxlike solids. When using normally liquid'keton'es for the treatment of the metal surface, I simply immerse the metal article in a bath of the ketone or mixtures there0f, and wipe off, or drain off, any excess liquid." Surface adsorption is almost instantaneous. Phenyl hexyl ketone is liquid and is a satisfactory material to use. One of the best ketonic compounds is that'prepared from com peratures as low as 0 C. and the metal article can be immersed therein, or the metal surface can be sprayed with the ketonic material.

painted, lacquered or otherwise ornamented with coating compounds in ways well known. 'Allof the usual coating compounds adhere strongly to the pre-treated surface.

I shall now list many ketones which used. in the practice of my invention. For economic reasons many of these ketones would not be used since they are somewhat expensive in comparison with ketones like the above-described mixtures of xylyl-alkyl ketones, the phenylheptadecy'l ketones, andothers produced in part from benzene and naphthalene. But in order to indicate the breadth of my invention, I am listing many difierent types of ketones falling within my generic disclosure. As stated, in most instances I find it more economical to use the cheap ketones, or various mixtures thereof, such as phenyl heptadecyl ketone, mixtures thereof with xylyl heptadecyl ketone, etc. Proportions in such mixtures are not at all critical; whether mixtures are to be used will be governed largely by the cost of the ketones. I

A representative list of ketones I can use is as follows: i

Phenyl heptadecyl ketone I p- Tolyl heptadecyl ketone m-Xylyl heptadecyl ketone -p-Xylyl heptadecyl ketone m-Xylyl pentadecyl ketone p-Tolyl pentadecyl ketone p-Methoxyphenyl pentadecyl ketone p-Ethoxyphenyl pentadecyl ketone Phenyl undecyl ketone p'-Chlorphenyl undecyl ketone p-Methoxyphenyl heptadecyl ketone p-Methoxyphenyl undecyl ketone p-Phenoxyphenyl heptadecyl ketone p-Phenoxyphenyl tridecyl ketone p-Phenoxyphenyl undecyl ketone v p-Nitro phenoxyphenyl heptadecyl ketone p-Methyl phenoxyphenyl heptadecyl ketone Alkyl phenones from lard fatty acids. Alpha naphthyl heptadecyl ketone Alpha naphthyl pentadecyl ketone Anthracyl heptadecyl ketone (mixtures) Biphenyl heptadecyl ketone Biphenyl tridecyl ketone Biphenyl undecyl ketone p-Methyl biphenyl heptadecyl ketone p-Chlorbiplienyl heptadecyl ketone Furyl heptadecyl ketone Furyl undecyl ketone Methyl furyl heptadecyl. ketone Dibenzoiuryl heptadecyl ketone I Dibenzofuryl undecyl ketone.

Consequently, in the appended claims I define my ketonic materials broadly as those in which one of the radicals attached to carbonyl is a closed ring radical and the other is analkyl radical having at least six carbon atoms.

Likewise, in the appended claims I wish to define the metal treated broadly. Apparently all metals will adsorb molecular layers of my ketonic their alloys do not however corrode or rust as readily as iron or steel. Copper and aluminum will, of course form oxide layers unless otherwise protected and my invention can be used to keep copper from discoloring as a result of atmospheric influences. My invention is especially useful in'the treatment of steel and'iron surfaces, and it can even be used to prevent silver from tarnishing. Silver articles tarnish readily due to contact with hydrogen sulphide in the atmosphere. Anjadsorbed layer of ketonic material on the silver prevents this. Since the ketonic films are of molecular dimensions they cannot, of course, be detected by visual inspection and the treated silver does not have a greasy or waxy feel. 4

It will be apparent that many other metal surfaces are benefited by the processes of the present invention. Ornamental aluminum on the exterior of'buildings can be kept shiny'if pre-treatedwith my ketones prior to exposure to the atmosphere. Aluminum foil, and other metal foils used for heat insulation can be maintained shiny so that a maximum amount of heat wherein R a closed ring compound and R is an alkyl radical having at least six carbon atoms. I

2. The article as in claim 1 wherein R is an aryl group. 3. The article as in claim 1 wherein R is a phenyl radical.

4. The articleas 'in claim 1 wherein R is a xylyl radical.

5. The article as in claim 1 wherein the ketonic material is a mixture of isomeric xylyl-alkyl ketones in which the alkyl group contains at least eight carbon atoms.

6. A steel article having a surface provided with a corrosion-resisting film of a ketonic material composed of at least one ketone having the formula wherein R is' a closed ring compound and R is an alkyl radical having at least six carbon atoms.

.tonic material is a mixture of isomeric xylylalkyl ketones in which the alkyl group contains at least eight carbon atoms.

11. The process of protecting the surface of metals against corrosion which. includes treatposed of at least one ketone having the formula.

wherein R is a closed ring compound and R is 14. The process as in claim 11 wherein R is a xylyl radical.

15. The process as in claim 11 wherein the ketone is a mixture of isomeric xylyl-alkyl ketones in which the alkyl group contains at least eight carbon atoms.

16. The process of, protecting the surface of steel articles against corrosion which includes treating the surface with a ketonic material composed of at least one ketone having the formula wherein R is a-closed ring compound and R is an alkyl radical having at least six carbon atoms.

17. The process as in claim 16 wherein R is a phenyl radical.

18. The process as in claim 16 wherein R is a phenyl radical.

19. The process as xylyl radical.

20. The process as in claim 16 wherein the ketone is a mixture of isomeric xylyl-alkyl ketones in which the alkyl group contains at least eight carbon atoms.

in claim 16 wherein R is a VICTOR CONQUEST.