US2403067A - Anticorrosion composition - Google Patents

Description

proportions are stated hereinafter.

Patented July 2, l6

2,403,067 anr'rcoanosron at @SETMJN Paul W. Fischer, Long ach, and Vance N. Jenkins, Palos Verdes Estates, tilaiiik, assignors to Union Oil Company or California, hos

Angeles, Calif., a corporation oi @alito No Drawing. Application September a, was, Serial No. 50Ll2d Claims. 3

only good lubricating properties but also good anticorrosion properties and good nonemulsifying and de-emulsifying characteristics. characteristics are imparted b the additive material oi the present invention which is at least primarily an oil-=soluble fatty acid amide containing an allryl substituent. The invention, however, is not necessarily limited to application to turbine oils but may be used in connection with other lubricants which might contain water or come in contact with water or become contaminated with water, such as various lubricating oils, greases, cutting oils, soluble oils, marine lubricants, rust inhibitors of liquid or paste type, and the like. Also, rust-removing compositions may contain indicated proportions of the. mentioned amide-type material.

The principal object of the invention .is to provide turbine oils and similar petroleum products of the mentioned type which will possess the necessary anti-corrosion characteristic and will at v the same time meet current specifications for such oils, such as the United States Navy specifications for nonemulsifying and de-emulsifying characteristics in turbine oils. Another important object is to provide products possessing good rust-inhibiting and rust-removing characteristics.

Briefly stated, the invention resides principally in an appropriate petroleum fraction containing the indicated amide-type material in very minor proportion but sufllcient to impart the desired anticorrosion properties. Such a. material shall be normally liquid and readily oil-soluble. For turbine oils the preferred proportions of the agent are about 0.1% to 0.2%. Other usable Where used for turbine oils and the like, the above mentioned nonemulsifying and tie-emulsifying characteristics must be present; although in cases of some soluble oils, cutting oils, and the like, emulsifying characteristics in the product are not particularly objectionable. Broadly stated, the mentioned amide type material is produced by 2 reacting oleic acid or kindred unsaturated fatty material (as hereinafter described) with an ali phatic alcohol amine (alkanolamine). which contains alkyl groups of a sumcient number of carbons to yield an oil-soluble product, and having at least one tree hydrogen on the nitrogen where All of these by the corresponding amide forms? The product possibly contains also an appreciable proportion oi esterified amide as hereinafter described.

Amines oi the monoethanol amine type do not yield sumciently oil soluble products. The amine apparently must contain an alkyl group Or roups totaling at least four carbons per molecule to impart suficient oil-solubility. The best material so far produced has been obtained with dlethanol amine. in general, oleic acid, or similar high molecular weight oil-soluble unsaturated fatty acid is preferred, but fats containing 'very large proportions ol'the glyceride of oleic acid have been successfully used.

Therefore, the invention in a preferred. form resides in petroleum fractions containing minor proportions of the amide produced from diethanol amine reacted with oleic acid or fatty oils of the mentioned type, to yield the indicated ethanclamine, dipropanolamine and butanolamine products mentioned, so long as corrosioninhibiting properties are not materially reduced, as on account or excessive chain length or other reason. a

Since preparation of the present product requires heating for a muchlonger time than to produce amine soaps of the fatty materials, whereby to pass from the soap stage into the amide stage, the invention also resides in the methodof preparation and also in products produced by such method.

According to the present invention, the proportions of amide which are normally employed are in the order of about 0.1% or 0.2% for turbine oils and the like, although for such uses the proportions may vary, as between the limit of about 0.001% or 0.01% and about 0.5%. For these purposes greater proportions than about 0.2% seem normally to impart no added benefit. However, in other instances such as for rust-removers, penetrating oils, cutting oils and the like, greater proportions such as in the order of 1% to 2% may be satisfactorily employed. The invention therefore also extends to these greater proportional ranges for the indicated types of products.

In general, the following specifications will elate to products containing the preferred amide, that is, the amide produced by reacting diethanol amine with oleic acid, whereby a diethanol oleyl amide is produced. Apparently the product contains also an appreciable proportion of such amide where the alcoholic OH group of part of the material is esterified by oleic acid to yield the earliermentioned esterifled amide. The invention, as has been indicated, is not limited to oleic acid product inasmuch as fatty materials may be employed containing large proportions of the glyc--. eride of oleic acid, especially where they contain only small proportions of materials yielding oilinsoluble products. Thus, lard oil may be employed instead of oleic acid,and any resultant otherwise. oil-insoluble products which are not solubilized by the soluble amides may be removed. Also, the same types of reaction product obtained from the mono-bu-tanol and dibutanol amines and from dipropanol amines may be employed.

The reaction between oleic acid and diethanoi amine to produce soap is presumed to be as follows, where R represents the oleic radical in general:

Following the soap-forming operation it appears that additional heating causes water to be split out to form the amide according to the following: I ncoonnmoiniomi heat R(fi.N(CzH40ll) m0 It now seems probable that an appreciable proportion of an esterified amide, perhap sometimes a much as 25% (but usually less), is formed along with the above indicated amide, inasmuch as to obtain the desired complete reaction more oleic acid is employed than would be accounted for if the amide alone is formed. Such a reaction is speculated to be approximately as follows: V

at imciniomi Corresponding reactions-occur of course with the other indicated amines. It is possible that small proportions of other reaction product are formed such as furane ring compounds which may or may not be objectionable and may in fact have some value.

' Example 1 A preferred method for producing oil-soluble diethanol oleic amides of the present invention is the following:

300 grams of oleic acid and 105 grams of com- 7 for about ten hours to insure rather complete reaction. The time of treatment may vary according to conditions, e. g. pressure, as will be apparout to one skilled in the art. Ordinarily, the product of this reaction is the final product, inasmuch as filtering ordinarily is not required. This material has excellent corrosion resistance in compositions herein described.

Example 2 of Example 1 and likewise possemed excellent corrosionresistance.

Where the products of the present invention are intended for use in turbine oiis,.it is apparently important that a substantially pure oil-soluble diethanol oleic amide be obtained and that it be as near neutral as p ssible. Preferably such an amide is obtained by employing oleic acid. However, for some of the uses above indicated, it is permissible to employ fatty oils, i. e. normally liquid fats, which contain relatively large proportions of glycerides of oleic acid. In man instances of such other uses, it is possible to employ other oil-soluble unsaturated fatty acids than oleic acid, and corresponding glycerides, although ordinarily oleic acid (which ha only one double bond and is non-hydroxy) or fatty oils containing large proportions of glycerides of oleic acid are to be preferred. Also, doubtless palmitoleic acid, which is found in some oils as glyceride, and

other similar acids which have only one double bond and are non-hydroxy, may be used.

Thus, olive oil is a desirable starting material inasmuch as it represents about 80% to 85% of oleic acid with only about 10% of saturated fatty acids. Peanut oil also may be employed, which represents about 60% of oleic acid and about 20% .of .linoleic acid. Cottonseed oil representing beiii) ; saturated fatty acids.

tween 30% and 35% of oleic acid and around to of linoleic acid also is an acceptable material. Corn oil is another desirable fatty oil inasmuch as it represents about 45% oleic acid and about 40% linoleic acid, with only about 10% of Two other possible oils representing only about 10% of saturated fatty acids are soya bean oil and linseed oil. While these oils will yield good products from the anticorrosion standpoint they have the practical objection of containing more than of the two and three double-bonded linoleic and linolenic drying oils. Linseed oil probably would be the more objectionable because it represents only 5% oleic acid and an objectionably large proportion of drying oils, i. e. about of linoleic acid and approximately 25% of linolenic acid, whereas the soya bean oil represents nearly 35% of oleic acid, about 50% of linoleic acid, and only 2% or 3% of linolenic acid. The objection to these materials containing two and three double bonds is that in many uses their products may oxidize and form sludges too readily.

Another oil which will be more desirable than linseed oil is lard oil which contains 50% to 60% of oleic acid and not substantially over 10% of linoleic abi d with little or no linolenic acid, although there is an objectionably large content of the saturated palmitic and stearic acids totaling about 35% to 40%. Other oils which it is possible to1 use are rapeseed oil, sesame seed oil and rice O1 It appears that a portion of the otherwise oilinsoluble amides from the saturated fatty acids is solubilized by the presence of the oil-soluble amides of the unsaturated fatty acids. For most uses, the solubilized portions of the saturated fatty acid amides are not objectionable. Where there are excess proportions of the saturated fatty acid amides which are not solubilized, these may nevertheless be retained where they are not objectionable, as in the case of solid reases. However, where these oil-insoluble amides tend to cloud out of liquid products in an objectionable manner, they may be removed from the liq uid amide product itself, or from oil-solutions or the like by settling, filtering, or otherwise. Also,

From the foregoing, it will be apparent that,

the single double-bonded non-hydroxy oleic acid itself is ordinarily preferred, and that fatty oils containing relatively large proportions of oleic glycerides with only small proportions of saturated fatty acid glycerides andonly small proportions of plural double-bonded, unsaturated,

drying type glycerides are next preferred. It is also apparent that the smaller the proportion of the saturated fatty acid content of the oil the more desirable, and at the same time the smaller the proportion of the drying oil type the more desirable the oil will be for the present uses. Thus, in general, olive oil and peanut oil represent preferred oils because they have relatively small contents of both saturated fatty acid glycerides and drying type glycerides. Corn oil also is usable because of its low saturated fatty acid content and its high oleic acid content even though there is a relatively large linoleic acid content. Lard oil is desirable despite its high saturated fatty acid content, inasmuch as the drying oil content is .very' small and the oil-insoluble materials can be separated.

In general, unsaturated non-hydroxy fatty acids in the class of saponifiable or high molecular weight fatty acids, or those containing at least about ten carbon atoms per molecule, may be used. Also their glycerides, such as are found in fatty oils may be employed for some purpose as herein described.

Example 3 Thus, according to one process where an unsaturated fatty oil was employed, 300 grams of lard oil were heated with 108 grams of diethanol amine in a liter glass beaker at atmospheric pressure under a temperature of about 300 F. for

about twelve hours substantiall as described in.

Example 1. Since lard oil is an ester of glycerol, the product contained a corresponding propor tion of free glycerol as well as the resultant diethanol oleic amides and corresponding amides of the other fatty acids present. Since glycerol tends toward emulsiflcation this product is not especially useful in turbine oils, but'is useful for many of the other indicated purposes. This particular product also was liquid at normal temoil at normal temperatures. preparation of liquid oils, any .solid material apparently from the saturated fatty acids forms and settles out of this product. This material dissolves in oil with heat, but settles out of the Therefore, in the should be removed from liquid amide products, from which it separates, before making up the oil.

As is apparent from the foregoing descrip tion, materials of this invention must be predominantly oil-soluble in order to be effective. As previously indicated, the oil-soluble amide products produced from the indicated unsat urated fatty acid materials must be produced with alkanol amines whose alkyl radicals have sufiicient carbon-content to render the'product oil-soluble, a total of at least four carbons per molecule apparently being necessary. Thus, the methanol amines and the monoethanol amine produce relatively oil-insoluble products, whereas diethanol amine, dipropanol amines and the butanol amines produce soluble products as heretofore stated. By the term "oil-soluble material is meant material that does not settle or cloud out of the oil at normal nor storage temperatures nor at temperatures of use.

Other variations coming within the scope of the appended claims will be apparent to those skilled in the art, such as the employment of other oil-soluble, unsaturated fatty acid materials and the employment of other available amines, including iso-products, as hereinbefore generally indicated.

We claim:

'1. A non-aqueous anti-corrosion composition comprising mineral oil in which is dissolved in the order of 0.001% to 2.0% of a material containing an oil-soluble alkanol amide of an unsaturated non-hydroxy fatty acid, the alkanol 'constituent containing at least four carbon atoms and the fatty acid constituent containing at least ten carbon atoms.

where is the fatty acid residue.

' 5. A composition according to claim 1 in which the alkanol amide has the formula 7. A composition according to claim 1 in which the alkanol amide is diethanol oleic acid amide.

mi amide of an unsaturated non-hydroxy fatty acid, the alkanol constituent containing at least four carbon atoms and the fatty acid constituent containing at least ten carbon atoms.

11. A composition according to claim 10 which the fatty acid is oleic acid.

12. A composition according to claim 10 in the order of 0.01% to 0.5% of an oil-soluble alkawhich the alkanol amide is an amide of diethanol amine.

. 13. A composition according to claim 10 in which the alkanol amide is diethanol oleic acid amide.

14. A non-aqueous anti-corrosion compositio comprising mineral oil in which is dissolved in the order of 0.001%-to 2.0% of a normally liquid oil-soluble material containing an alkanol amide of an unsaturated non-hydroxy fatty acid and an esterlfied form of said alkanol amide, the alkanol constituent of said alkanol amide containing at least four carbon atoms and the fatty acid constituent of said'alkanol amide containing at least ten carbon atoms.

15. A composition according to claim 14 in which the alkanol'amide is diethanol oleic acid amide.

PAUL W. FISCHER. VANCE N. JENKINS.