US2128523A - Composition for use in prevention of corrosion of metal surfaces - Google Patents

Description

"testedbyme and tionoi' iron and Patented Aug. 30,1938

umrsp STATES P T comosmou 2.128.5 I FOR USEIN PREVENTION OF oFFi-cs' I CORROSION F METAL SURFACES Arthur w. Burwell, Nia

to Alox Corporation,k

, poration of New Yor No'prawinz.

. This invention relates to methods for the proagainst c0r-.

tection of corrodible metal surfaces mama, and is concerned more particularly with rived from petroleum, shale oil, hydrocarbonaceous starting materials such as tar oils from the low temperature coking of coal.

lignite, etc.

- I have found that the rustingof exposed surfaces of iron and steel articles may for a longer period be prevented by application thereto, by prayin like,

Filmsof the partia y oxidized petroleum hydrocarbon products e, in general, very thin; particularly when applied in solution form and the solvent thereafter stronger protective films are desired, I may and frequently do associate with the partially oxidized petroleum hydrocarbon products one or more thickening-solidifying or strengthening agents, such, for instance as rosin, rosin oil, drying oils,

petroleum products ployed therewith and (2) substantially chemical- I ly inert to the metal. Thereby} enhance the protective qualities ofmy anti-corrosion agents against the hazards of rough handling of the articles protected therewith.

nl'ms have been exhaustively The aforesaid by agovernmental agency. and to be efllcacious in the protechave been found steel surfaces against moisture,

gal-a Falls, N.

, adapted for l and not greater than about 21, assignor New" York, N.'Y.', a corpplication June 29,1936, Serial m. 88,058

Claimaemoist air containing halogen lacids, salt spray sunshine. .Exposures of metal, e. g., iron and steekssurfa e's, so protected, for periods of over two weeks, to aqueous nitric acid have had no effect on the films and no corrosive .en'ect on the metal "surfaces. Likewise, the films have been found to be impenetrable b'y alternate sprays of caustic and carbonate dust with inter.- mediate washing with water. Salts dried on such have enfound to have .no efl'ect in penetratingthe'same to cause corrosion of the underlying metal. drums exposed in'the neighborhood of escaping gaseous chlorine, salts sprays containing high percentages ofcaustic soda. caustic soda dust from caustic melting pots,

sunshine-all combined-have had sl eet, snow, no effect upon the illrnsi the drums remaining exactly of the same appearance as when exposed all of which are, v v two or more thereof, theoxidatio'n being effected by blowing air or other oxygen-containing gas (e. g., oxygen-enriched air) through .aliquid body of the petroleum hydrocarbon mixture maintained at a temperature above at least 100? 0.

185- superatmospheric pressure of from and in the Patent Nos. 1,690,768

scribed is that disclosed in Arthur W? Burwell.

and 1,690,769, granted to The resulting reaction product is a mixture of a great number of different compounds which may, for clarity, be.grouped thus:

1. Unoxidized (i. e., 2. Aliphatic alcohols, largely secondary and .tertiary;'

3. Aliphatic ketones; 4. Ketc-alcohols;

oz-iginal) hydrocarbons;

solutions, nitric acid, aqueous nitric acid, mix

- e process above de- 5. High molecular weight saturated aliphatic y carboxylic and hydroxycarboxylic acids; etc.; and

hydrocarbon products, I have 6. Neutral esters and lactones derived from the aforesaid acids and the aforesaid alcohols, or from the aforesaid acids, respectively.

Differently grouped, the mixtures are separable broadly into (a) saponifiables and (b) unsaponifiables: into the latter group fall the alcoholic and ketonic compounds aforesaid (and, of course, the unoxidized hydrocarbons), whereas the acids, esters and lactones. are grouped as saponifiables.

Any and all of the aforesaid oxidized petroleum found, have to some extent the property of arresting the corrosion of iron and steel surfaces. However, I prefer to select as the base of the anti-corrosion composition one or more of the neutral types'of oxidized products,-i. e.; the neutral, unsaponiiiable, alcoholic, ketonic and/or keto alcoholic compounds, because they do not offer the possibility of soap decomposition and, moreover, because they in general yield tougher, harder anticorrosion films than do the acids or salts and esters of those acids. In this connection I note that I prefer to employ in the present relation the'unsaponifiable partial oxidation products obtained from ceresin or from higher melting point petrolatums, since theseiyield tougher films,

which films apparently fin'dergo a progressive. toughening apparently akin to the toughening of have found to be particularly advantageous the unsaponiflable films of drying oils. Thus, 1

neutral bodies separated from the reaction product obtained by oxidizing (in the manner above described) a mixture of amorphous wax and paraffln wax.

As stated above, these neutral mixtures may be applied, as such, to the metal surfaces to be protected, the normally solid products being for.

this purpose heated to above their melting points. In lieu thereof I may employ a solution of the neutral mixture in an appropriate organic solvent, e. g., a light petroleum distillate such as gasoline or the special petroleum distillate known as Stoddard solvent. Thus, Inlay use a composition comprising 40%, more or less, of-the aforesaid neutral bodies and 60%, less or more, of Stoddard solvent or equivalent.

For greater protection against acids (e. g., acid mists) Imay and preferably do incorporatewith the unsaponifiable compounds, or in their solutions or compositions, an amine such-as an ethajnol amine (e. g., triethanol amine) or other more or less volatile amine. Where amines are added, I prefer to use them in the ratio of the equivalent of 1 part byweight of triethanol amine to from 20 to 1,000 parts by weight of the aforesaid neutral bodies. This latter mixture may, advantageously, be used in the upper cylinder parts of automotive engines, gines which have been run with gasoline containing tetraethyl lead mixtures, which mixtures almost always contain halogen organic compounds. These compounds burn in the explosion chamber forming halogen acids which penetrate the metal parts and cause serious corrosion upon access of moisture or after the lapse of considerable time, especially under conditions of higher temperature together with moisture. These halogen acids being in the metarmust be neutralized by means of some soluble alkali or soapsof alkali metals soluble in the materials forming the film. In this connection, it is possible to dissolve either sodium or potassium soapsv of the aforesaid acids in the alcoholic ketonic bodies described, the whole being then melted and painted upon the surfaces or dissolved in particularly airplane enaraaeas suitable solvents and sprayed upon the surfaces or otherwise applied.

The invention will be described with greater I particularity with reference to the following fur- The above may be used warm, or diluted with a suitable quantity of thinner or solvent.

Example 111 Parts by weight The aforesaid neutral unsaponifiable bodies from a mixture of parai'fin and amorphous waxes 5-25 Rosin (or rosin hardened with lime) 15-5 Linseed oil, to make 100 This may be applied in undiluted state, or may have thinner added.

Example N Parts by weight i The aforesaid neutral unsaponifiable bodies from a mixture of paraffin and amorphous waxes 5-35 Triethanolamine a. 0.5-5.0 Rosin oil 2040 Stoddard solvent, toimake 100 Example V Barts by weight The aforesaid, neutral unsaponifiable bodies from road wax 5-2.0 Tlmg oil... l -80 This composition, which gives an especially tough film, may be applied, as such, in warm state, or admixed with a suitable'volatile solvent. Example VI Parts by weight The aforesaid neutral unsaponiflable bodies from Sharples wax 5-40" Finely divided iron oxide -3 10-5 Linseed oil, to make Instead of the iron oxide of the above example I may use a substantial amount of another pigment such, for instance, as lead carbonate zinc oxide, lithopone, or the like. Instead of the linseed oil, I may employ another drying oil, e. g., tung oil.

I Ewample VI; The aforesaid neutral. 'unsaponiflable bodies from ceresin wax Triethanolamine Dichlor diethyl ether, to make It is to be understood dichlor diethyl ethef another suitable volatile solvent may be used.

I claim: 9

1. Film-forming protective composition adapted for use on metal surfaces, consisting essentially that in place of the ketones, aliphatic keto-alcohols and neutral esters and lactones 01' high molecular weight saturated aliphatic carboxylic acids, said composition being substantially anhydrous and inert to metal. v 2. Film-forming protective composition as defined in claim 1, of neutral unsaponiflable oxidized petroleum hydrocarbons is dissolved in a relatively volatile organic solvent therei'or.

3. Film-forming protective composition as delined in claim 1, characterized in that a filmtanning thickening agent is admixed therein.

- for use on metal characterized in that the mixture protective composition as de- 4. Film-forming is admixed therein.

5. Film-forming protective composition adapted surfaces, being an oily solution oi a mixture oi neutralunsaponiflable saturated oxidized hydrocarbons obtained by the liquidphase partial oxidation or a hydrocarbon aa'rmm w mmwm.