US1436729A - Rustproofing coating - Google Patents

Description

. Patented Nov. 28, 1,922.

STATES J'ERE SCANLLAN, OF DEARBOBN, AN'ID HENRY GARDNER, OF DETROIT, MICHIGAN.

RUSTZPROOFING COATING.

No Drawing.

To all tohomitmayconcemr Be -1t known that we,. Jenn. SOANLAN and Hnnnx GARDNER, citizens of the United States, reslding at 133 Mason Street north,

' Dearborn, and 2745 Third Avenue, Detroit,

a rust-proofing for metals and a method for accomplishing the rust-proofing which is simple, and inexpensive while being, at the same time, durable.

A further object of our invention is to provide a rust proof coating for metals, such as iron or steel, which will really prevent rust on the surface of such metals so long asthe coating remains intact and which at the same time will have a black or other color so that the metal may be finished over the rust proof coating with any. suitable coloring of siccative material. 0

A further object of our invention is to utilize a ,known method of rust-proofing in combination with means for coloring such rust proof coatingto conform to the color of the finish with which the metal is to be coated. t i

With these and other zobjects in view, our invention consists in tfhe process of forming the coating -and the coating itself as de; scribed in this specification and set forth in the claims. I

In the practise of our invention we first coat the material to be rust proofed, such as iron or steel or any metal of a ferrous nature, with zinc or zinc alloy plating by any of the well known methods for forming such platings such for instance as by electrolysis. The method of coating or platlng the material with zinc will not be here more particularly described because it forms no part of the invention .in connection with this application.

In connection with zinc plating, we believe that this type of rust proof coating for ferrous metals is superior, in so far as prevent ing rust is concerned, to any other typeof rust preventative coating. Zinc plating,

- however, is subject to the disadvantage that it cannot be successfully enameled. or lacquered for use. in connection with metals which are exposed to the weather and which require a hlg fimsh such for instance as an Application filed March 22, 1922. Serial No. 545,874.

tomobile parts. Where such coatings of varnish or the like are attempted over -zinc plating a large number of such coatings are reuired in order to give a pure black color to t e material and even then the coating tends to chip off when it becomes thoroughly dry. In fact the enameling of zinc plating, so far as we know, is conceded to be impracticable,

commercially.

After the material to be rust proofed has been so coated with the zinc we then subject it to a hot bath of an antimony solution which will form on the zinc a closely adhering metallic deposit of dead black or other color which can be given a very beautiful finish by simply applying thereto one coat of enamel. I

By our invention we are, therefore, enabled to secure the well known advantages of the zinc plate rustproofing together with a .decrease in the number of coats of enamel required to secure any desired finish on'the metal, thereby securing a durable and desirable finish for steel parts or for. ferrous parts which are to be exposed-to the weather and which require a high finish. v

In the practice of our process we have experimented with various thicknesses of zinc plating with various solutions of antimony,

and with varioustimes for exposure of the plated article to the antimony: We were very successful in accomplishing our coating of the zinc plated article with the metal lic antimony by dipping articles into a very hot solution of butter of antimony (antimony chloride diluted in the 'proportion of one part, antimony chloride, British Pharmacopia strength, to 1200' parts water). Where one pint'of the butter of antlmony was used to 150 gallons of water, the water was brought to a temperature averaging the boiling point. Caustic sodato the amount of two pounds was added to this solution.

Our experiments show, however, that it is not necessary to use caustic soda, (NaOH) for an alkali in connection with this solution, as good success was obtained from potassium salts and more articularly from potassium carbonate, (K 0 or from sodium hydroxide. Our experiments further show that other salts ofantimony than antimony chloride SbCl and other salts which fall into the same class with antimony chloride, namely, arsenic, bismuth, and phosphorus, may be .used.--

In fact our invention consists in the col 45 more fully set forth as it is not our desire to oring of'the rust preventing zinc coating on various metals by means of some compound of the antimony group, an acid forming element such as chlorine and an alkaline solution.

The point of using the caustic soda or other alkali is to neutralize the disintegrating effect of the acid used with the antimony compound, as this acid tends to disintegrate the zinc coating thereby lessening its rust proofing ability. Where, however, a slightly alkaline, neutral, or a very slightly acid solution of a salt of antimony is used, practically no disintegration of the zinc coating takes place, and a very even deposit of metallic antimony may be formed on the zinc. The thickness of this deposit depends upon the relative proportion of antimony in the solution and the length of time thatthe article is left in the solution. F orinstance, an article left in the solution made as described above, for approximately three minutes will have a very good coating of metallic antimony deposited thereon.

The advantages of our improved method of rust proofing are believed to have been brought out in the main in the specification hereinafter, but it should be again pointed out that by our process we are enabled to secure the advantages of the best rust proof coating with which we are familiar and at the same time we are enabled to provide a ferrous article with a very high finish with but very few coats or one sic-cative coating.

It will be understood that some variations may be made in the proportions of the solution herein described and that the temperature may be varied somewhat, changes in the proportions resulting, however, in correspending increases or decreases in the time for a coating to be formed, and changes in the heat of the solution resulting similarly. Different salts of antimony will be used also to give colors other than black. These coatmgs, however, of other colors are not herein cover by this application any particular method of coating ferrous material to obtain any color other than black as each such color is obtained by varying the salt of antimony used, so that we desire to cover the methods of obtaining the specific colors separately, and to cover the method of producing the black, and the method generally, in this application.

What we claim is:

1. The method of coating the surfaces of ferrous articles for rust proofing consisting of first plating such surfaces with zinc or zinc compounds and then depositing metallic antimony on the plated surfaces.

2. The method of coating the surfaces of ferrous articles for rust proofing consisting of first plating the articles with zinc or zinc compounds, then coating the plated surface with metallic antimony, and coating the surface thus formed with a siccative coating.

3. The method of rust proofing ferrous surfaces consisting of first plating the surface with zinc or zinc compounds and then subjecting the plated surface to the action of a solution of antimony chloride.

4. The method of rust proofing ferrous surfaces consisting of first plating such surfaces with zinc or zinc compounds and then subjecting the plated surfaces to the action of a hot solution of a salt of antimony and a forming acid.

5. The method of rust proofing a ferrous surface consisting of first coating the surface with zinc then subjecting it to a solution of a salt of antimony and a forming acid, and then coating the 6. The method of rust proofing ferrous surfaces consisting of zinc plating such surfaces and then subjecting them to a hot bath formed from a solution of a salt of antimony, a forming acid, and an alkali.

7. The method of rust surface consisting of zinc plating the surface and then subjecting it to the action of a hot solution of a salt of antimony, an acid, and sufficient alkali to render the solution near neutral.

8. The method of rust proofing of ferrous surfaces consisting of zinc plating such surfaces and then subjecting the plated surfaces to a substantially neutralized acid solution of a salt of antimony;

proofing ferrous surface thus formed with a .siccative coating. 4

9. The method of coating ferrous surfaces for rust proofing consisting of zinc plating the surfacesand then subjecting them to a hot bath formed from a solution of'a salt of antimony, an acid, and potassium salts.

10. The method of rust proofing ferrous surfaces consisting of zinc plating the surfaces and then subjecting them to a solution of antimony chloride and caustic soda 1n substantially the proportions of one pint of antimony chloride, two pounds of caustic soda, and one hundred and fifty gallons of water.

11. The method of rust proofing of ferrous surfaces consisting of zinc plating such surfaces and then subjecting the plated surfaces to a substantially neutralized acid so lution of a salt of antimony substantially in the proportions specified.

February 6, 1922.

J ERE SCANLAN. HENRY GARDNER.