US1795883A - Noncorroding composition - Google Patents

Description

Patented Mar. 10, 1931 OFFICE JOHN W. ORELUP, OF EAST ORANGE, AND OSCAR IVAN LEE, OF JERSEY CITY, NEW

JERSEY NONCORRODING COMPOSITION No Drawing.

The present invention relates to a noncorroding composition. More particularly, it isconcerned with the problem of rendering non-corrosive certain compounds or mixtures I employed as freezing point depressants for use in the cooling systems of internal combustion engines, especially automobile and aeroplane engines. The particular substance which has received greatest attention from 19 us and which is best taken as illustrative of our invention, is calcium chloride. This substance in many respects makes an ideal freezing point depressant, but its extensive employment has been prevented, due to the fact that solutions of this substance corrode the metallic parts of the cooling system. \Vhile a number of expedients have previously been proposed to render its solutions non-corrosive, none so far as we know has been suc- 20 cessful.

We believe that the chief cause of the corrosive elfectof calcium chloride and similar salts is due to the electrolytic action set up in the cooling system by virtue of the fact that such systems comprise a number of different metals e. g. brass, copper, iron, aluminum, etc., which form an electrical circuit that takes on and gives up electrical energy in the presence of strong electrolytes such as calcium chloride. We have observed that the corrosion decreases with increase in purity of the dissolved substance, but it cannot be entirely eliminated by this means alone even though extremely pure materials are used.

Not onl is this true, but it is a practical impossibility to maintain the cooling solution in a radiator free from contamination.

We have now discovered that the incorporation of certain substances with the depressant or electrolyte will substantially prevent corrosion of the metallic parts comprising the cooling system. To date we have determined that the following substances either alone or in combination with one another possess this property to a satisfactory degree when used with calcium chloride or similar depressant: dispersed vanadium pentoxide, or other dispersed combinations of vanadium, salts of thorium, zirconium, molybdenum, tantalum, columbium, titanium,

Serial No. 65,675.

Per cent Dispersed vanadium pentoxide 50 so D spersed uranium-thorium hydroxides 30 Dispersed zirconium oxide 20 The relative proportions of the ingredients may be Widely varied and the above example 1s given as one of a large number possible with the substances herein disclosed. By the term dispersed we preferably mean in the sol condition in which the oxides appear to the eye to be clearly soluble, although actually they are in a colloidal state. Various known ways may be employed to effect this sol condition, as for example, vanadium oxide sol may be prepared by first dissolving same in alkali and then treating with a few drops of acid or acid chlorides. In case of the other compounds mentioned, dispersion takes place without first dissolving the alkali and then acidification due to the action of the calcium chloride. This small amount of dispcrsed material is snflicient to act as a corrosion inhibitor and does not settle out upon standing.

Small proportions of the above mixture, when added to a solution of substantially pure calcium chloride, or the equivalent, will render such solution substantially non-corrosive to the metal parts of the cooling system of an internal combustion engine. In practice we have found it convenient to employ from 04% to .05% of the above mixture to a 38% solution of pure calcium chloride. This solution of calcium chloride is somewhat stronger than will ordinarily be used in practice. For use in the 5 latitude of New York city, it may be diluted with the same volume of water and a solution obtained which will have a sufficiently low freezing point. In general the strength of the calcium chloride solution is immaterial 1w so far as the corrosion preventing properties of the substances of our invention are concerned. The amount of the corrosion preventing composition added may be also varied considerably. In many cases it may be desirable to incorporate a suitable coloring matter with such mixture.

It is conceivable thata corrosion inhibiting substance or compound may act in one or more of the following three Ways:

(1) The inhibitor may combine with the corrosive elements, nullifying their effect.

(2) The inhibitor if of a basic nature will eliminate any acid which may be formed during the process of corrosion.

(3) The inhibitor will automatically form or cause to be formed coatings or coverings on the metals affected by electrolysis, as for example, aluminum, thereby preventing the corrosion. way in which paint protects iron from rust.

While the first two explanations may account in a measure for the action of our improved composition, although such explanations apply in a greater degree to certain organic compounds which have proposed for this use, our experiments and tests indicate that the inhibiting composition of our invention acts by forming or causing to be formed a coating on the metals which effectively protects them from corrosion.

As we have above indicated the best results will be had when substantially pure calcium chloride is used, as otherwise the impurities present may be so great that their corrosive action cannot be nullified by the materials which we add.

One process of purifying commercial calcium chloride which may be used is to dissolve the solid calcium chloride in alcohol and then precipitate the impurities by adding acetone and letting stand. Crystals of sodium chloride, soda alum and other impurities are deposited and-may be filtered 01f, or the supernatant solution decanted. The alcohol and acetone may be recovered by distillation and used over and over again. The calcium chloride so purified is brought into solution with water to the desired concentration and the amount of inhibitors necessary added.

By the term compound in the claim is meant to include, salts, oxides, hydroxides, or hydrous oxides of vanadium, thorium, zirconium, molybdenum, tantalum, columbium, titanium, tungsten and uranium.

We claim:

1. A. freezing point depressant for use in the cooling systems of automobile engines and the like, comprising substantially pure calcium chloride and containing a dispersed, insoluble metallic oxide capable of forming a coating on the metal parts of such systems protecting same from corrosion from said depressant.

This action is analogous to the- 2. A freezing point depressant for use in the cooling systems of automobile engines and the like and containing a metallic compound capable of forming a coating on the metal parts of such systems protecting same from corrosion from said depressant, said compound containing vanadium.

3. A freezing point depressant for use in the cooling systems of automobile engines and the like and containing a metallic compound capable of forming a coating on the metalparts of such systems protecting same from corrosion from said depressant, said compound containing dispersed vanadium oxide and dispersed uranium and thorium hydroxides.

4. A freezing point depressant for use in the cooling systems of automobile engines and the like and containing a metallic compound capable of forming a coating on the metal parts of such systems protecting same from corrosion from said depressant, said compound containing dispersed vanadium oxide, dispersed uranium and thorium hydroxides and zirconium oxide.

5. A' freezing point depressant for use in the cooling systems of automobile "engines and the like, containing dispersed vanadium oxide for protecting the'metal parts of said systems from corrosion from said depressant. v 6. A freezing point depressant for u'se in the cooling systems of automobile engines and the like and containing a metalliccompound capable of forming a coating on the metalv parts of such systems protecting same from corrosion from said depressant,. 'saicl. compound being comprised of any ofthe following in a dispersed,ins0luble form compounds of vanadium, thorium, zirconium,

.molybdenum, tantalum, columbium, titanium, tungsten, uranium. v

In testimony whereof We have affixed our signatures to this specification.

JOHN ORELUP. OSCAR IVANLEE.