US2545138A - Corrosion inhibiting compositions - Google Patents

Description

Patented Mar. 13, x 1951 CORROSION INHIBITIN G COMPOSITION S Werner David, Chester, England, assignor to Shell Development Company, San Francisco, Calif., a corporation of Delaware No Drawing. Application February 2, 1948, Se-

rial No. 5,907. In Great Britain June 30, 1947 9 Claims (Cl. 252-33) This invention relates to compositions having ability of displacing moisture, corrosive materials and the like from corrosive surfaces. This invention also pertains to the formation on such surfaces of a non-corrosive moisture resistant protective film. More particularly thi invention pertains to corrosion inhibiting compositions suitable for protecting metal. and non-metal surfaces by rendering them impervious to water, electrolytic solutions, corrosive fluids, gases, and the like, by displacing said contaminant from said surfaces and forming thereon a tenacious protective film having good lubricating properties.

It is well known that moisture, corrosive fluids and gases; e. g. E28, S02, etc., readily attack not only metallic surfaces but non-metallic surfaces and cause corrosion, rusting, pitting and other damage to such surface. Also, aqueous solutions when in contact with a metallic surface readily attack it and cause corrosion and rusting. Under certain conditions the problem of corrosion becomes exceedingly serious because once started it is progressively accelerated. Thus, oils containing small amounts of water become very corrosive to metals in contact therewith. .This ,is due to the fact that oils and particularly liquid petroleum hydrocarbons are very good solubilizers of oxygen, and any moisture present theresuch as mineral oil or gasoline, to water-is limited, ideal conditions for rusting and corrosion are set up. The presence of electrolytes andfor mation of corrosive decomposition products in oils and the like also greatly increase the rate of corrosivity.

Under conditions where, in addition to those enumerated, elevated temperatures are encountered, corrosive activity is greatly accelerated.

Thus moisture, salt sprays and other contaminants or acidic decomposition products and corrosive gases formed during operation of engines,

such as internal combustion engines, Diesel engines, aircraft engines, turbines and various other machinery and industrial equipment, readily attack and rust or corrode contacting metal surfaces. The damage thus caused is not to the metal surface alone for rust particles frequently-[ break off and enter the circulating system of engines and cause plugging, clogging, and fouling of conduit lines, columns, plates, and the line of cracking equipment, tubes, evaporators, etc.

Corrosion of alloyed bearings and other alloyed surfaces due to contact with water can attain such an aggravated stage as to cause great fatigue stresses to be set up, which ultimately result in cracking of the metal.

The problem is equally serious when combating rusting and corrosion of steel drums, storage tanks used to store gasoline, hydrocarbon oils and the like.

Moisture adhering to pickled steel, quenched steel, equipment such as instruments, engine starters and generators on landing crafts, hydraulic systems, machinery for metal processing and the like are alsoyextremely susceptible to corrosion and must be protected.

Rust preventative, water displacing compositions are particularly desired in metal rolling operation such as prior to cold rolling of metals. Generally, prior to cold rolling, metal sheets or strips are hot rolled, and then subjected to the following operations:

(a) A pickling operation wherein, if desired, an inhibitor is added to the pickling bath;

(1)) A washing of the steel sheet or strip to remove the pickling agent;

(0) A drying of the sheet or strip, for example, by means of a hot air blast; followed, if desired by (d) An oiling treatment to inhibit corrosion, particularly if the metal thus treated is to be stored for some time prior to cold rolling.

After the material has ben subjected to these operations it is cold rolled, generally using, as a lubricant and cooling agent, a soluble oil emulsion. Subsequently, the articles are annealed, and then subjected, if desired, to a light rolling without oil through highly polished rolls. The object of this step is to confer some degree of hardness to the metal and also to burnish it,

thus producing a pleasing polished appearance.

The cold rolling process carried out in the above described manner suffers from various drawbacks. Washing, drying and oiling operations are expensive in time, labor, and cost, and moreover, unless the oil composition is carefully selected it is frequently found to be the cause of staining after the article has been annealed and thi is probably caused by catalytic decompositionof oil vapors on the metal surface being I annealed.

From the above description of metal rolling it can readily be appreciated that simplification of the process by elimination of the drying, washing and subsequent oiling step is greatly desired. This can be accomplished by use of water-displacing compositions of this invention prior to the cold rolling step.

been coated or treated with greases, fatty oomthereon an impermeabletenacious protective film. It is another object of this invention to protect metallic surfaces with a water .displacing'water resistant noncorrosive protective film having no 1 detrimental effect upon the metal surface treat- In order for water displacing compositions to be effective they must act rapidly and thereafter spread uniformly and quickly over the surface treated, adhere tenaciously thereto and protect the surface from corrosion. In addition, waterdisplacing compositions should possess the following properties:

(1) They should be immiscible with water;

(2) They should be stable under all conditions of use or in storage;

(3) They should be non reactive with contacting surfaces being treated;

(4) They should provide protection to "15113 5111".- face treated for long periods of time;

(5) They should possess some degree of lubricity; and

(6) They should not cause staining ,ormarring of the surface.

Countless materials and compositions have been tried for protecting surfaces, such as metal 'sur'faces', against damage caused by watencorrosive fluids and the like by forming-on said-surface a non-reactive corrosion'protective filmhaving lubricating properties. Metal surfaces have positions, waxes, organic compounds, e. g. or-

chemical reactive inhibitors are incapable of penetrating the surface being protected and are incapable of displacing the contaminant there from. In cases where such inhibitors are able to form protective coatings on surfaces they are easily displaced by moisture or rupture readily. They are relatively ineffective against corrosive acidic materials and hot gases such asare formed during operation of combustion and turbine engines and are easily destroyed when applied to surfaces which are subjected to high temperatures.

It is an object of this invention to-protect metal surfaces in contact with corrosive contaminants against corrosion by treating said surfaces with acomposition having the property of displacing said contaminants from said surface and forming ed. It is still another objectof 'thislinvention to provide metal surfaces with a water and acidresistantfilm which is not susceptible to rupture .cven'at elevated'temperatures and which could be readily removedwhen desired. Still another obcapableof protecting metal surfaces from corro- 'sion, -said composition also possessing lubricating properties. Another object is to form film-.forming metal protective compositions which are stableand readily misciblewith petroleumhydrocarbons 'such as lubricating oils or other inert Organic carriers and the like. It is also another 'objectof this invention to treat surfaces whether metallic or non-.metallic so as'to form thereon a protective film which is impervious to moisture agents and fiimeforming agents.

4 and corrosive fluids, and which can be readily removed when desired. Other objects will be apparent from the following description.

It has now been discovered that various metals and other materials subjected to corrosive influences can be protected simply and eifectively by treatment with a composition of matter comprising essentially "a blend comprising a major amount of a hydrocarbon and/or mixtures of said hydrocarbons, synthetic lubricants, fixed fatty oils and the like, and minor amounts of specially selected wetting agents, spreading The additives :of this composition must be present in a rather critical amount, and must be present at all times during the active life of the composition in order "to function asJan effective water displacing, noncorrosive, protective film-forming composition.

Thedispersing medium is substantially a waterimmiscible hydrocarbon or a mixture of hydrocarbons such as petroleum oilsorother :type of oils, :or "their derivatives. These carriers or dispersing mediums are preferably derived from pc- .fonate, and the like, can The used.

'troleum hydrocarbons and may include various petroleum naphtha cuts, :mineral spirits, lubritcating nil distillates, mineral seed oil, kerosene, gas oils,.mineral lubricating oil, transformer oil, white oil, kerosene .302 extract, aromatic solvents, petroleum ether, aromatic (hydrocarbons such :as benzene, :pexyl'ene, o-xylene, m-xylene, cumene, butyl benzene; paraifinic hydrocarbons, e. g. normal hexane, :dimethyl pentane, octane, nonane, undecane, dodecane; cycloparaffin, e. g. .cyclohexane, .methylcyclohexane, isopropylcyclohexane; synthetic oils such as polymerized .alkylene .oxides, polymerized olefins, esters, e. g. 2- ;ethylfhexyl sebacataetc. The dispersing medium :is usually present in amounts of between "about and about of the composition, depend- ;ing upon'its viscosity,-penetrability and particular applicationpr condition under which it is used. Preferably, the base oil 'shouldnot exceed a viscosity of about 65 seconds Redwood I at -F., and-should contain little .or no free or combined sulfur.

Additives which have the power of wetting metal and-like surfaces and of displacing moisture and other contaminants therefrom so as to allow direct contact and adherence of the protective agent-tothe'surface,are salts of sulfonic acid such as :ammonium, amine, alkali, alkaline earth and heavy metal salts of petroleum sulfonic acid derived from substantially light petroleum fractions rich in aromatics, preferably having an aromatic content between-5% to 10%. Particularly suitable for forming the sulfonates are petroleum naphthas, kerosene, transformer oils and the like. The sulfonates can be formed by any conventional means. For example, petroleum naphthas or kerosene fractions rich in aromatics canbe treated 'withsuitable amounts of sulfuric :acid to-obta'in sulfonic acids. These acids can be recovered :by alcoholic extraction and thereafter neutralized with alkali to form the alkali metal salts of these-sulfonic acids. 'Sulfona'tes produced Jfonates -derived from alkylated aromatic e. g.

'butyl naphthalene sulfonate, diwax benzene sul- If desired various pthemsalts "of :said sulfonic acids can be 75 used.

Instead of using the sulfonates derived from light petroleum fractions as the sole wetting agent, other well known wetting agents can be used in combination therewith. Among them can be included esters and various salts of organic compounds containing a minimum of 8 carbon atoms in the molecule. Particular examples are soap or salts of fatty materials or petroleum acids obtained by oxidizing parafiin waxes, the alkali and alkaline earth metal salts, e. g. sodium,

potassium, calcium or magnesium salts of wool grease, degras fatty acid, oleic acid, stearic acid, petroleum acids-alkali salts of sulfated alcohols having between about 8 to 20 carbon atoms in the molecule, e. g. sodium oleyl sulfate, sodium lauryl sulfate, sodium ocenol sulfate, ammonium lauryl sulfate; neutralized alkylated aromatic thereof are cottonseed oil, rape oil, menhaden oil, sardine oil and the esters thereof.

Any of the above oils can be blown by conventional means such as by air at elevated tempera Table I Per ce t s Gr. at Iodine Sap. Value insoluble in 15 0. Value petroleum ether Pure rape oils 0.913 to 0. 917 94 to 106 -170 to 179 0 Blown rape 01ls 0. 968 to 0.975 47 to 52 209 to 217. 24 to 27 Pure cottonseed oil 0.922 to 0.925 108 to 110 191 to 198 0 Blown cottonseed oil 0. 972 to 0.979 56 to 65 214 to 225 26 to 29 sulfates; and alkali salts of monoand polyalkyl esters of sulfodicarboxylic acid, e. g. sodium salt of diamyl sulfo succinic acid, sodium salt of dilauryl sulfo succinic acid, disodium monocetyl monosulfo succinate, etc.

The wetting agents of this invention, such as alkali sulfonates derived from low boiling petroleum hydrocarbons rich in aromatics when used alone or in combination with other wetting agents referred to above, possess the unique property of displacing moisture from metal surfaces and in.

addition act as powerful penetrants, which however are readily displaceable by the protective film-forming agent of this invention. This is apparently due to the fact that these wetting agents are substantially miscible with and have a great afiinity for water, enabling them to remove moisture from the metal surface and allowing the penetrant-and protective film-forming agent to come in direct contact with the surface being treated.

The amount of preferred sulfonate wetting agent, which may be ammonium or sodium sulfonate, referred to above, when used either alone or in combination with other wetting agents varies between about 2% and about 5%, and preferably between about 2% and about by weight. When in combination with other wetting agents it is generally preferred to employ predominant amounts of the petroleum sulfonate.

The protective film-forming,- water-displacing agents of this invention are blown or thickened animal, vegetable and/or fish oils and derivatives thereof, such as the full or partial esters of said oil. Among such esters may be included the mono, di'and/or triglyceryl ester of capric, lauric,

myristric, palmitic, stearic, arachidic, behenic, oleic, linolein, ricinoleic acids and the like. These esters may be simple or mixed. In addition other fractions of said oils which are unsceptible towards a blowing treatment may be used. Oils which are suitable for use include: cottonseed oil, rape oil, kapok oil, corn oil, soyabean oil, pumpkin seed oil, beechnut oil, mustard oil, rice oil; seal oil, whale oil, menhaden oil, sardine oil,

cod liver oil, neats-foot oil, tallow oil, lard oil,

and the like; The preferred oils and derivatives These blown oils have the unique property of displacing moisture from metallic surfaces and forming thereon a tenacious protective film. Just how blown oils perform this function is not exactly understood but it is believed that the polar groups formed during blowing have a strong affinity for water, allowing the rest of the material to adhere tenaciously to the metal surface and form a protective film thereon.

The protective film-forming water-displacing agents are generally used in amounts varying from 3% to 5% by weight.

To aid in spreading the film-forming metal protective agent evenly, minor amounts of cycloalkanols having between about 5 to 19 carbon atoms in the molecule and preferably between about 4 to 8 carbon atoms, are added to compositions of this invention. Cyclic alcohols may include cyclohexanol, 4-tertiary amyl cyclohexanol, di-tertiary amylcyclohexanol, methylcyclohexanol, amylcyclohexanol, dimethylcyclohexanol, naphthenic alcohol, cyelobutanol, amyl cyelobutanol, quinitol, carvomenthol, menthol, *beta and alpha terpineol, terpin and derivatives of cyclic alcohols such as obtained by intermolecular dehydration of an alkitol to produce polyhydric cyclic ethers. By an alkitol is meant a polyhydricalcohol having atleast four carbon atoms and at least four hydroxy groups such as erythritols, pentitols, sorbitol, mannitol, and the like. Thecyclic alcohols need not be used in amounts above about 10% by weight and usually range from 5% to 10%.although under certain conditions they need not exceed 5% by weight. The alcohols function as spreading agents. Thus once the wetting agent with the aid of the penetrant succeeds in wetting the surface and removing the moisture -or other contaminant, the alcohol helps spread uniformly the film-forming protective agent on to the treated surface.

All ingredients which constitute the present composition must be present at all times. The absences of any one ingredient reduces the overall efficiency of the composition to such a degree as to render it almost useless as a moisture displacing corrosion inhibiting composition. I

In order to more fully illustrate preferredcommedial-3B .7 position-of this invention, the .=following "finished compositions are tabulated sherein below and should not be construed :as a limitation of this invention.

The'following table :further illustrates compositions of this invention which-are beneficial for displacing contaminants as .described from various surfaces.

Table III Components 1 'Blown'corn oil Blownsesame. oil- .r "gnu-Hour.

The components listedccn be dispersed in any suitableIhydrocarbonsuch.as-mineraloiLikeroscne, gas oil, mineral seal oil; mineral spirits andtlielikein snamountvtheitotal of which preferably docs notexceed about 15%by Weight.

The following example :illustrates the applicability of compositions of this invention to the cold rolling .ofsteel sheets or strips.

A hot rolled steel strip wide and 0.092% thick .coil :form was passed ;continuously through apicklingbath' which .was'maintained at between about 35'C..ande90 C. The pickled strip was then :passed through a Washing chamber where water-was:sprayed onsaid strip. It .then is passed through ;a tank containing .a composi- .tion .of this invention preferable as noted in the Table :II above, where all the water adhering to the strip is sdisplaced. The displaced water settles rrapidly 'out'of :the composition and :is .removed from ithe bottom of the tank at convenient :times. The strips on leaving this tank pass through felt pads in order to remove excess oil adhering tothestrip.

The strip is :then cold rolled to 0.007" thickness. This rolling operation may be done im- ,mediately. after'thestripleaves'the oil tank or the :strip .may be .re-ooiled :and left to stand until irolling ;is convenient. After rolling, the strip is .annealediin an'electricjfurnace an atmosphere :of cracked ammonia gas at about 700 :C.

The surface finish of strips treated :as above are remarkably "good :and :are greatly superior to the .finish of similar steels treated :by the usual process utilizing thermal dipping, oiling and soluble oil emulsion application during cold "rolling. Furthermoresurfaces treated with compositions of this inventionaregfreestrom stains :and other undesired deposits.

While the above example illustrates the preferred method .of carrying out-the process .of :cold rolling zsteel :using compositions of this invention, various modifications can be made which may be apparent "to those skillediin the art of steel :rolling. Thus, suchprocesses may be confil tinuous or batchland-the compositions of this in vention may applied by prayin d pping, swabbing and the like.

Besides metal surfaces, materials such ;as rubber, electrical insulation -materia1s, brake and clutch lining :and the like may be treated with compositions of thisinvention whenever it is desired to displace water from them.

.Although theessential ingredients which -c.on .stitute compositions of .this invention must be present, other additives can be included such as linear polymer thickeners, asphalts, pour point depressor-s, :dyes, alkyl and alkyl l a nes, organic acid, e. g. oleic, stearic, :cresylic naphthcnic acids, phenolic compounds and the like. The addition .of such additives are particularly desired when compositions of this invention are required to be used as temporary lubricants.

The present compositions may be applied to a surface to be protected by a means such as immersing, flooding, spraying, brushing, trowelling and the like. The protective film formed on said surfaces adheres tenaciously enough to withstand handling, light polishing, movement and high temperatures for long periods of time. It can be removed when desired by a suitable solvent'or by simply rubbing with a cloth.

The present invention having thus been fully described is not to be limited by any specific examples which have been presented herein solely forthepurpose of illustration, but only by the following claims.

This application is a continuation-in-part of my pending application Serial No. 734,875 'filed March 14, 19.47.

I claim as my invention:

'1. A 'corrosionand rust-inhibiting lubricating composition adapted to displace moisture from metalsurfaoesprior to being metalworked and prevent corrosion, said composition having the following formula and proportions:

Per cent by weight .Mineral lubricating-oil to Sodium salt of petroleum naphthasulfonic acid derived from a petroleum :naphtha containing from 5 to 10% aromatics .2 to 5 Blown rape oil 3 to 5 Methyl oyclohexanol :5 to 10 '2. A corrosionand rust-inhibiting lubricating composition adapted to displace moisture from metal surfaces prior to being metal worked and prevent corrosion, said composition having the following formula and proportions:

From about 85 to about.95

,Frcmabout 2 to about -5 ,Blownrapeoil From about -3 to about .5

Methyl 1c y:c1 oh ex anol From about 5 to about 10 3. A corrosionand rust-inhibiting mineral ilubrioating oil composition adapted to displace moisture frommetalsurfaces containing a total notexceeding about 15% by weight, and eachlad- :ditivebeing inabout equal proportions of sodium .salt of petroleum naphtha sulfonic acid derived from a petroleum naphtha containing from 5 to 10% aromatics, blown rape oil and methyl cyclohexanol.

4. A corrosionand rust-inhibiting mineral lubricating oil composition adapted to displace moisture from metal surfaces containing a total not exceeding about 15% by weight and each additive being in about equal proportions, of ammonium salt of petroleum naphtha sulfonic acid derived from a petroleum naphtha containing from 5 to 10% aromatics, blown rape oil an methyl cyclohexanol.

5. A corrosionand rust-inhibiting mineral lubricating oil composition adapted to displace moisture from metal surfaces containing a total not exceeding about 15% by weight and each additive being in about equal proportions, of salt of a petroleum sulfonic acid, blown vegetable oil and cycloalkanol.

6. A corrosionand rust-inhibiting mineral lubricating oil composition adapted to displace moisture from metal surfaces containing a total not exceeding about 15% by weight and each additive being in about equal proportions, of salt of a petroleum sulfonic acid derived from a petroleum naphtha containing from 5 to 10% aromatics, blown vegetable oil and cycloalkanol.

7. A corrosionand rust-inhibiting mineral lubricating oil composition adapted to displace moisture from metal surfaces containing a total not exceeding about 15% by weight and each additive being in about equal proportions, of salt of a petroleum sulfonic acid derived from a petroleum naphtha containing from 5 to 10% aromatics, blown fatty oil and cycloalkanol.

hydrocarbon lubricating composition adapted to displace moisture from metal surfaces prior to being metal worked containing a total not exceeding about 15% by weight and each additive being in about equal proportions, of a salt of a petroleum sulfonic acid derived from a petroleum fraction containing from 5 to 10% aromatics, blown fatty oil and cycloalkanol.

' WERNER DAVID.

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

UNITED STATES PATENTS Number Name Date Re. 17,722 Millring July 8, 1930 2,121,475 Corkery June 21, 1938 2,182,992 Lebo Dec. 12, 1939 2,348,715 Adams et al. May 16, 1944 2,359,738 Schiermeier Oct. 10, 1944 FOREIGN PATENTS Number Country Date 5 469,889 Great Britain Aug. 4, 1937

Claims (1)

1. A CORROSION- AND RUST-INHIBITING LUBRICATING COMPOSITION ADAPTED TO DISPLACE MOISTURE FROM METAL SURFACES PRIOR TO BEING METAL WORKEDWORKED AND PREVENT CORROSION, SAID COMPOSITION HAVING THE FOLLOWING FORMULA AND PROPORTIONS: