US2588412A

US2588412A - Mineral oil compositions

Info

Publication number: US2588412A
Application number: US49660A
Authority: US
Inventors: Albert G Rocchini
Original assignee: Gulf Research and Development Co
Current assignee: Gulf Research and Development Co
Priority date: 1948-09-16
Filing date: 1948-09-16
Publication date: 1952-03-11
Anticipated expiration: 1969-03-11

Description

Patented Mar. 11, 1952 UNITED STATES PATENT "OFFICE MINERAL OIL COMPOSITIONS- Albert G. Rocchini, Springdale,1Pa.,. assignori to Gulf Research & Development .Company, Pittsburgh, Pa., a corporation of Delaware No Drawing. Applicationsepteniber16;19 i8,

' Serial No. 49,660

5 Claims. (Cl.-25251.5)

This invention relates to mineral oil-compositions, and in particular concerns mineral oil compositions adapted to protect ferrous and other metalsurfaces with which they come in contact "from rustin 'and other types of corrosion.

As is well known, simple mineral oil films afiord only limited protection to metal surfaces against rusting and other types of corrosion, and in eneral cannot be relied upon to provide sufiicient protectioninthe presence of'moisture or even under conditions of high humidity. "quent'ly, it has become common practice to employ Consecorrosioninhibitors or anticorrosion agents as additives in mineral oil compositions for the purpose of: providing additonal protection against rusting and corrosion. Such additives have been used in various types of lubricating compositions,

such as machine oils, turbine oils, internal combustion engine and diesel lubricating oils. greases,

Others of the compositions in which they are used, c. g., lubricating value, demulsibility, etc.

Accordingly, it is an object of the present invention to provide mineral oil compositions which protect metal surfaces with which they come in contact against rusting and corrosion underextreme conditions of service.

Another object is to provide mineral oil compositions capable of protecting metal surfaces 1 against corrosion even by salt water.

A further object is to provide improved mineral 1 oil i compositions containing an effective anticorrosion additive which does not adversely aiiect thedesirable prope ties of the oil itself.

herein-will occur to those skilled in the art upon- "em loyment of the invention in practice.

I have now found that t e above ob ects and "-attendantadvantages may be realized by incorporating into mineral oil compositions as an anticorrosionwadditive ta minor amount of a waterinsoluble, oil-soluble "reaction ::product between an aliphatic dicarboxyliczacid anhydrideconstaining as a substituentira hydrocarbon :radical .suchas an alkyl, aryl, alkenyl, aralkyl, oncycloalkyl radical'and a tertiary :amine. I;,-have1tound that reaction products'of this class are particu- 1 larly well adapted-for uses asanticorrosiomadditives for mineral oils,since they efiectively inhibit rusting and corrosion of metals, and'atlthezsame time do not adverselyafiect the lubricatingproperties of the oil.

The reaction products between ethersubstituted aliphatic dicarboxylic acid :anhydrides: and :the

tertiary amines can be prepared ina simplermanner. I have found-thattthey can be prepared efficiently by mixing equiv-molecular quantities of the anhydrideand the amine. In most cases the reaction beginsuponuadmixture, but if eVidence of reaction is not, immediately apparent, heatin is desirable inorder=to=start=the-reaction. To insure adequacyof reaction themixture should attain an elevated temperature; preferably atemperature of at least 250F. Where the heat of reaction. is suilicient to raise' the temperature of the mixtureat least to this point, no additional heat is required, but where:necessary it is advisable toheatthe'mixturezto' the temperature in question which should be maintained for atieast'five minutes. -The'products obtained are insoluble in water i and are -soluble in oil at "least to: an extent sufiicient to: permit their solution inoil'l-in anfwamount equal-toat least 0.005 per cent and preferablywat-least 1.0 per cent. The"preferred'=-reaction productsare obtained fromsubstituted :aliphatic: dicarboxylic acid anhydrides inrwhich the-substituent;con-

tainsat least six carbonatoms.

The reaction products aprepared as described above and adapted for use in the r compositions of the invention are relativelyhigh boiling, lightcolored, viscous liquids {to .darker-coloredpsemiliquids 1 or soft resinous solids. 'Inaddition "to being sufliciently soluble in mineral oils to act'as very effective corrosioninhibitorspthey are also soluble in such organic solvents -as hexane. chloroform; and benzene.

'The specific chemical nature "of the reaction products employed in accordance-with the invention is not understood. Since they "are prepared under anhydrousconditions employing the acid anhydride, theyare not simple'salts of the corresponding acid and the amine. Moreover,

salts between the acids and the' amines are" sold-- ble in water,= whereas'the' reaction=-productswith which this invention is concerned are substanwith water.

tially water-insoluble. On the other hand, all evidence indicates that the reaction products are not amides or imides. The formation of compounds of these types would require decomposition of the amine and in the research leading to the development of this invention, no evidence of I such decomposition has been found.

As indicated above, the preferred reaction products are those which are prepared from substituted aliphatic dicarboxylic acid anhydrides in which the substituent group is a hydrocarbon radical containing at least six carbon atoms. Reaction products of acid anhydrides having as a substituent an alkenyl group containing at least six carbon atoms are particularly advantageous. The especially preferred products are those obtained with the use of substituted aliphatic dicarboxylic acid anhydrides in which the substituent contains a relatively large number of carbon atoms, for example, 8 to 12 carbon atoms.

The substituted dicarboxylic acids employed in preparing the new anti-corrosion agents are all derivatives of the homologous series of which malom'c acid is the first member. Higher acids of this series include succinic, maleic, glutaric, adipic, pimelic, suberic, azelaic and sebacic acids, decane-dicarboxylic acid, undecane-dicarboxylic acid, etc. The substituent may be any hydrocarbon radical and preferably contains at least 6 carbon atoms; Examples of such substituents include alkyl and alkenyl groups of any chain length; aryl groups, such as phenyl, tolyl, xylyl, butylphenyl, naphthyl, xenyl, etc.; aralkyi groups, such as benzyl, phenylethyl, methylbent yl, etc.; and cycloalkyl, such as cyclohexyl, methylcyclohexyl, ethylcyclohexyl, cycloheptyl, etc. Mixtures of dicarboxylic acids containing diiferent substituents may likewise be employed.

Examples of tertiary amines which may be reacted with the substituted aliphatic dicarboxylic acid anhydrides in preparing the new anti-corrosion agents are the following: trimethylamine, triethylamine, triamylamine, triethanolamine, tribenzylamine, tristearyltriethanolamine, tri ethanolamine-ethylphosphatidic acid, and py-'- ridine.

, Any of the above, or mixtures thereof, or various oxygen, halogen, sulfur, nitrogen, or phosphorus derivatives of these compounds may be reacted with the above-defined class of dicarboxylic acids to form the anti-corrosion agents employed in mineral oil compositions in accordance with the invention.

The mineral oil compositions of the present in vention may be of various types having special properties adapting them for certain particular applications. Thus, they may be lubricating oil compositions. ranging from light machine and household oils to heavy lubricants for large internal combustion engines, including diesel engines. Alternatively, they may be of the nature of protective oils or greases, such as slushing oils or gun greases, or they may be adapted for use asmetal working oils or the like. They are particularly well suited for use as steam turbine oils since they provide adequate protection against rusting and corrosion in the presence of water and water vapor, and do not readily emulsify They may also be fuel oil compositions, including diesel engine fuels and domestic burner oils, whereby the anti-corrosion agent protects the tanks in which such oil is stored against corrosion brought about by the water with which such oils are often contaminated, as for example in the case of marine fuel oils which usually are contaminated with salt water, giving rise to very serious corrosion in the storage bunkers.

Regardless of the particular type of composition or the specific use to which it is adapted, the new compositions of the invention are prepared simply by mixing the herein-defined anti-corrosion agents with the desired mineral oil base to form a homogeneous composition. These agents function independently of other common oil additives, e. g., anti-oxidants, detergents, viscosity index improvers, anti-foam agents, demulsifyiiig agents, pour point depressants, etc., and accord ingly may be used in conjunction with such addi tives. They may be employed in varying amounts depending upon the severity of the corrosion con-- ditions under which the composition will be used.- Ordinarily, however, lubricating compositions contain less than about 1 per cent, usually between about 0.01 and about 0.5 per cent, of the anti-corrosion agent, based on the weight of the base oil, whereas slushing oil types of compositions may contain up to 10 or more per cent by weight of the corrosion inhibitor to provide adequate protection against corrosion during storage for long periods of time under very drastic climatic conditions.

In testing and demonstrating the efficiency of the new compositions in providing protection against corrosion, use may be made of the socalled ASTM Corrosion Test which is a'modification of that specified in the ASTM Standards on Petroleum Products and Lubricants, Septem-- ber, 1945, designated as ASTM D-665-44T. In brief,-this test consists in placing a 300 ml. sample of the oil or oil composition to be tested in a 400 ml. beaker which is immersed in a constant temperature bath maintained at 140 F. The beaker is fitted with a cover provided with openings for a stainless steel motor-driven stirrer and for insertion of a standard steel test bar, /2' inch in diameter and 5 inches long, which has been very carefully cleaned and polished just prior to the test. The stirrer is started and when the oil sample in the beaker reaches a steady temperature of 140 F. the test bar is inserted in the proper opening and hangs suspended from the beaker cover. After 30 minutes of stirring, 30 m1. of distilled water are added to the beaker, and stirring is then continued for 48 hours, after whi h time the test bar is removed and examined for rust spots. If there are no rust spots on the steel bar, the sample is said to pass this test. Any rusting of the bar indicates failure.

In a modification of the above-described test, artificial sea water having the following composition:

Parts by Weight NaCl 25.0 MgClz-GHzO 11.0 Na2SO4 4.0 CaClz 1.2 Distilled water 1000.0

corrosion agent and a refined lubricating oil having the following specifications:

Approximately 227 parts by weight (1 mol) of a technical grade of triamylamine were added in small increments to approximately 266 parts by weight; (1 mol) of mixed alkenyl succinic acid anhydrides. The latter material was a lightyellow, zoily liquid, commercial product consisting of a mixture of alkenyl succinic acid anhydrides in which the alkenyl substituent contained an average of from about to 12 carbon atoms. During the addition of the amine, heat was evolved and the mixture was maintained at about 250 F. for about 5 minutes. The resulting reaction product was a dark viscous liquid. A composition consisting of 0.10 per cent by weight of this product and 99.9 per cent by weight of the above-described base oil successfully passed both of the hereinbefore-described corrosion tests.

The base oil itself failed to pass either of these tests, as did a composition consisting Of 0.10 per cent by weight of the alkenyl succinic acid anhydrid dissolved in the base oil.

Example II Approximately 16 parts by weight of pyridine were reacted with approximately 54 parts by weight of the mixed alkenyl succinic acid anhydrides employed in Example I, substantially as described in that example. The reaction product obtained was a very viscous yellow liquid. A composition consisting of 0.05 per cent by Weight of this product dispersed in the base oil successfully passed both of the hereinbefore-described corrosion tests.

Example III Approximately 130 parts by weight of diethanolamine-ethyl-phosphatidic acid were reacted with approximately 26 parts by weight of the mixed alkenyl succinic acid anhydrides employed in Example I, substantially as described in that example. The reaction product obtained was a brown viscous liquid. A composition consisting of 0.10 per cent by weight of this product dispersed in the base oil successfully passed both of the hereinbefore-described corrosion tests.

Example IV the class of substituted aliphatic dicarboxylic acid anhydrides and tertiary amines. For example, by maintaining a mixture of triethanolamine and the mixed alkenyl succinic acid anhydrides described in Example I at a temperature of about 250 F. for a few minutes, a clear amber plastic solid is obtained which is an excellent rust preventive. The reaction product between the mixed alkenyl succinic acid anhydrides and triethylamine, prepared as described in the examples, is a very viscous sticky liquid which when added to the base oil so as to be present in the amount of 0.10 per cent by weight produces a composition that passes both of the hereinbefore described corrosion tests. Similar products are obtained by combining, under the conditions described in the examples, alpha-cyclohexylmalonic acid anhydride and triamylamine;alpha-hexyldecyl-malonic acid anhydride and triethanolamine; alpha-n-octyl-nonane dicarboxylic acid anhydride and pyridine; and alpha-benzyl-succinic acid anhydride and triamylamine.

This application is a continuation-in-part of my co-pending applications Serial No. 708,183

' and Serial No. 703,186, filed on November 6, 1946,

now abandoned.

Other modes of applying the principle of my invention may be employed instead of those explained, change being made as regards the methods or materials employed, provided the products defined by any of the following claims be obtained.

I claim:

1. An improved mineral oil composition comprising a major amount of a mineral oil and dissolved in said oil a minor amount of a waterinsoluble reaction product obtained by a process comprising maintaining a mixture of about equimolecular quantities of mixed alkenyl-substituted succinic acid anhydrides in which the alkenyl substituents contain an average of about 10 to 12 carbon atoms and an amine selected from the group consisting of trimethylamine, triethylamine, triamylamine, triethanolamine, tribenzylamine, tristearyl-triethanolamine, triethanolamine-ethylphosphatidic acid and pyridine, at an elevated reaction temperature of about 250 F. for about 5 minutes, the amount of said reaction product being sufficient to impart corrosion-inhibiting properties to said composition.

2. The composition of claim 1 in which the amine is triamylamine.

3. The composition of claim 1 in which the amine is pyridine.

4. The composition of claim 1 in which the amine is triethanolamine-ethylphosphatidic acid.

5. The composition of claim 1 in which the amine is tristearyl-triethanolamine.

ALBERT G. ROCCHINI.

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

UNITED STATES PATENTS Number Name Date 2,109,941 DAlelio Mar. 1, 1938 2,182,178 Pinkernelle Dec. 5, 1939 2,342,114 Blair Feb. 22, 1944 2,417,833 Lincoln et a1 Mar. 25, 1947 2,481,585 Freeman Sept. 13, 1949 2,490,744 Trigg Dec. 6, 1949

Claims

1. AN IMPROVED MINERAL OIL COMPOSITION COMPRISING A MAJOR AMOUNT OF A MINERAL OIL AND DISSOLVED IN SAID OIL A MINOR AMOUNT OF A WATERINSOLUBLE REACTION PRODUCT OBTAINED BY A PROCESS COMPRISING MAINTAINING A MIXTURE OF ABOUT EQUIMOLECULAR QUANTITIES OF MIXED ALKENYL-SUBSTITUTED SUCCINIC ACID ANHYDRIDES IN WHICH THE ALKENYL SUBSTITUENTS CONTAIN AN AVERAGE OF ABOUT 10 TO 12 CARBON ATOMS AND AN AMINE SELECTED FROM THE GROUP CONSISTING OF TRIMETHYLAMINE, TRIETHYLAMINE, TRIMYLAMINE, TRIETHANOLAMINE, TRIBENZYLAMINE, TRISTEARYL-TRIETHANOLAMINE, TRIETHANOLAMINE-ETHYLPHOSPHATIDIC ACID AND PYRIDINE, AT AN ELEVATED REAFTION TEMPERATURE OF ABOUT 250* F. FOR ABOUT 5 MINUTES, THE AMOUNT OF SAID REACTION PRODUCT BEING SUFFICIENT TO IMPART CORROSION-INHIBITING PROPERTIES TO SAID COMPOSITION.