US 3897349 A
Anti-rust additive composition:
Description (OCR text may contain errors)
United States Patent [191 Marin et a1.
[ July 29, 1975 ANTI-RUST ADDlTIVE COMPOSITION lnventors: Pierre Dominique Marin, Rouen; Robert Tirtiaux, Mont Saint-Aignan, both of France Assignee: Exxon Research and Engineering Company, Linden, NJ.
Filed: May 29, 1974 Appl. No.: 474,257
Foreign Application Priority Data May 29, 1973 U.S. Cl. 252/33.3; 44/66; 44/71; 252/34; 252/34.7; 252/51.5 R; 252/389 R; 252/392; 72/42 Int. Cl. C10m 1/32;C10m 3/26 Field of Search 252/33.3, 34, 34.7, 51.5 R, 252/392, 389 R; 44/66, 71; 72/42 References Cited UNITED STATES PATENTS Primary Examiner-Delbert E. Gantz France 73.19388 6/1950 Lieber 252/392 Assistant Examinerl. Vaughn Attorney, Agent, or Firm-Frank T. Johmann  ABSTRACT Anti-rust additive composition:
a. alkanolamine salt of fatty acid b. alkanolamine salt of aromatic acid c. free alkanolamine d. sodium alkylbenzene sulfonate e. mineral oil base 12 Claims, N0 Drawings ANTI-RUST ADDITIVE COMPOSITION The invention relates to an additive composition which is intended for use as an anti-rust agent in hydrocarbon-based compositions, for example petroleum oil compositions such as lubricants, liquid fuels and motor fuels; and more especially in emulsifiable oils for metalworking, whether or not those oils are hydrocarbon based. The invention further relates to compositions, for example emulsifiable oils, containing the additive.
Quite often, liquid hydrocarbon-based compositions are brought into contact with material made of iron, steel or cast iron, in the presence of water. Thus. liquid fuels and motor fuels are stored in tanks containers or holders, at the bottom of which there is always a certain quantity of water. Again, certain lubricants are used for lubricating mechanism that is exposed to water. Additives are commonly embodied in all these various compositions for the purpose of preserving the material from rust.
p More especially, it is essential to incorporate an antirust additive in the emulsifiable oils which are used for machine metals. The proper workingof a machine tool, lathe, milling and planing machines etc, requires the tool to be lubricated and cooled by spraying on to it a suitable liquid. When the flow of heat liberated by the tool is considerable, the liquid used in an emulsion of oil in water, containing from 1 to 10% oil. As a rule, this emulsion is prepared in situ, in the machining shop, by diluting an. emulsifiable lubricating composition in water. The emulsifiable lubricating composition must meet a certain number of requirements. ln particular, it must disperse spontaneouslyin water and, form an emulsion which is stable and does not foam. It is important for it to preserve from corrosion both themachine and the tool as well as the part being machined. It is also very important that foaming during metal-working operationsis minimized, preferably eliminated. ln practice these different requirements are difficult to reconcile.
Among the anti-corrosion agents normally included in-emulsifiable oils, the 'mostefficient are alkanolamides of low melting point, derived from fatty acids. Unfortunately, these products drastically affect the emulsibility of the oil in water. Other known additives include alkanolamine fatty ester compounds, and salts formed by neutralizing an acid such as oleic acid with the equivalent quantity of an alkanolamine. However these types give rise to heavy foaming during their use in, for example, cutting oils.
One object of the present invention is an anti-rust additive which is intended for use in hydrocarbon-based compositions and also for use in emulsifiable oils, whether they are hydrocarbon-based or, for'example, are based on synthetic lubricant compounds.
The invention also includes an emulsifiable oil containing such an additive and, still further, an emulsion formed from such an oil.
According to the invention an anti-rust additive essentially comprises l a. at least one salt of at least onealiphatiecarboxylic acid having 6 to 20 carbon atoms per molecule and at where R is a hydroxyalkyl group and X and Y are the same or different groups'selected from hydrogemalkyl and hydroxyalkyl. v 1
The free alkanolamine is very preferably the same as that present in the salt. When the additive contains several alkanolamines, a chemical balance is established spontaneously between the free alkanolaminesand the alkanolamines contained in the salts.
lt willrbe seen that in the'additive according to the invention for each equivalent of alkanolamine(s) incorporated with the acid(s) in the salts, thereare from 0.5 to 2 equivalents offree-alkanolamine(s) present. Preferably there are l to 2, advantageously l to l .7 equivalents of-free alkanolamine(s). 1 i
The alkanolamines can be primary, secondary and tertiary alkanolamines. having only one alcohol func-- tional group, for example-monoethanolamine isopropanolamine. N-dimethylethanolamine, N- diethylethanolamine,' N-dimethylisopropanolamine and N-diethylisopropanolamine.
They can also be secondary or tertiary alkanolamines having two or three alcohol functional groups, forexample diethanolamine, N-methyl diethanolamine, .N-
ethyl diethanolamine and diisopropanolamine; triethanolamineand triisopropanolamine. .1 a
Preferably a mixture of alkanolamines is present, for instance a mixture of mono, di andtri-ethanolamine, or a mixture diand tri-isopropanolamine. Advantageously the mixture is of diisopropanolamine and triisopropanolamine.
The carboxylic acids are those whose molecule contains from 6 to 20 carbon atoms, inclusive, preferably 10 to 20, advantageously 10 to l8. Suitable aliphatic acids are saturated acids, for example caprylic, decanoic, lauric, myristic, palmitic and stearic acids; or un-- saturated acids, for example linoleic, linolenic, oleic and undecylenic'acids'A mixture of aliphatic acids may be used, for example tall oil acids.
It was foundgthat the said aliphatic acid/alkanolamine salts tended to form gels when they were dispersed in a hydrocarbon oil. This drawback is avoided, in accordance with the invention, by including said-aromatic acid/alkanolamine salts. The weight ratio (calculated as freeacids) of aromatic acid to aliphatic acid ,is from 0.1,: l to 10": I
The aromatic acid is preferably a direct ringsubstituted compound, for example benzoic acid or a naphthoic acid. The molecule of the aromatic acid may also containother functional groups, for example hydroxy, amino, amido, nitro, :alkoxy groups. For instance, hydroxybenzoic or an amino-benzoic acid may be used. The molecule of aromatic acid may also contain one or more lower alkyl groups, such as methyl, ethyl, isopropyl,-isobutyl, provided that the total numso that thegtemper-ature of reaction is less than 130C,
and very. desirably not vmore than 120C. From 100-l20C is usually'found suitable.
The additive of the present invention has several advantages over the alkanolamides generally used as antirust agents in emulsifiable oils..First of all, it is more effective. Moreover, contrary to the usual alkanolamides, it is not detrimental tothe emulsibility of the oils. Finally it has unexpected anti-foaming properties.
The invention also provides an anti-rust emulsifiable composition comprising the foregoing anti-rust additive and an emulsifying agent, forexample one or more sodium alkylbenzene sulphonates. In: addition the cmulsifiable compositionmay also contain a solubilizing agent forassisting'andstabilizing oil-in-wateremulsions formed from the cmulsifiable composition. Such an agent is, for examp1e,-butyl glycol or butyl cellosolve.
The present invention also includes within its scope an'emulsifiable =oil whose properties are improved by the use of this additive. This oil contains the usual constituents of cmulsifiable metal-working oilsult is based on a mineral oil having a viscosity of 10 to 200 cSt at 50C. The cmulsifiable oil contains emulsifiers in sufficient quantity'ito confer on it the desired emulsibility. This proportion is for preference between 10 and by weight. The emulsifiers can be selected from the usual emulsifiers. lt is possible to use in particular soalkylbenzene sulphonates, sodium =alkyl sulphates-sodium salts of fatty acids. sodium salts of colophony, re'sinic acids. Use is made for preference of a mixture of emulsifiers including an anionic emulsifier anda non-ionic emulsifier. I K
This cmulsifiable oil contains for preference up to 5% by weight of an extreme pressure lubricating agent of the-usualappropriate type. It contains advantageously up to 3% of a bactericidal agent. for instance a quaternary ammonium salt. lt is characterised essentially in that includes from 1 to 5% by weight of' the anti-rust agent of the present invention. I
lt suffices to dilute this oil with water to prepare an emulsion which is suitable as a lubricant for metal working. The emulsion thus obtained. which may contain from I to for preference 1 to 10%, by volume of the cmulsifiable oil defined above, is also included A mixture was formed of the following:
I -Bcnzoic acid 13 parts by weight Laurie acid 1-1 "Diisopropanolamine 38 Triisopropanolaminc 35 .This mixtureth'erefore contained 2.7 equivalents of alkanolamines for every equivalent of the acids.
This mixture was melted by heating it to C 1 10C. lt was thn allowed to cool. The product obtained is one according to the invention and is an homogeneous liquid'(Product A).
Example 2 A 'emulsifiable anti-rust oil (Hlwas obtained by adding 2 parts by weight of product A as described in example 1, to IOO'parts by weight of an cmulsifiable oil (HO) whose composition was as follows:
Lubricant base 70% The lubricant base was a mineral oil of the spindle oil type. characterised by a viscosity of 13.3 cSt at 50C. By mere dilution of oil H in water. in 1 vol% concentration, a lubricating emulsion for metal-working was obtained.
The anti-rust properties'of this emulsion wereassessed by means of the Herbert test-(British Standard lP -63). hereafter called the 1P performance test. On a carefully cleaned grey cast iron plate was arrangeda layer of steel shavings and on to them were poured a few millilitres of the emulsion being tested. 24 hours'later; the shavings were removed and the surface of the plate'was examined.
It was found that the anti-wear agent according to the invention, added in the proportion of 2% to the soluble oil. makes it possible to obtain the complete protection of the metal from rust. v
Example 3 The same test was carried out as in Example 2, the product A being replaced by various commercial antirust additives bearing the reference B. C, D and E.
B and C are alkanolamides of oleic acid. D is a mixture of alkanolamides obtained by condensing tall oil acids with diethanolamine. E is a salt formed by neutralizinga C oxoacid with one equivalent of tripropanolamine.
For each of these anti-rust additives the minimum proportion was determined that has to be added to the said oil HO (EX. 1) to obtain complete protection of the metal from rust.
The following results were obtained:
Example '4 This example shows the anti-foaming properties of the product to which the invention refers. The emulsifiable anti-rust oil' H defined in Example 2- was diluted 5 vol% in water.
The emulsion thus obtained was subjected to the test which is described in ASTM standard D-892. In a graduated 1000 ml. test-tube were placed 190 ml. of the emulsion. The test-tube wasplaced in a bath kept at 24C. Glass was blown into the sample through a glass frit plate arranged at the bottom of the test-tube. After 5 minutes the blowing in of air was stopped and the volume. of froth formed was at once noted. Finally. minutes later, the volume of froth still remaining was noted.
The same test was repeated, replacing the 2 vol.% A in'the soluble oil HO (EX. 2) by 2 vol.% of the commercial product B (see-EX. 3). The test was further repeated with 5 vol% of A and also with 5 vol.% of products B, C, D, and E (see EX. 3) and F, an amine dioleate ester. The test was again repeated employing A at 5 vol% but changing the alkanolamine (G to .l).
The following results were obtained:
It is clear that the additives according to the invention (A and G to J) endowed the emulsions with very superior anti-foaming properties.
Example 5 To prepare another anti-rust additive and according to the invention, the following were mixed together:
16 parts by weight of para-aminobenzoic acid.
16 parts by weight of n-decanoic acid 69 parts by weight of triethanolamine This mixture therefore contained 2.5 equivalents of triethanolamine to each equivalent of the acids. The mixture was melted by heating it to about 1 10C, and then it was allowed to cool. The product obtained was a homogeneous liquid.
Example 6 Additives were made by forming salts of various carboxylic acids (l mole) with triethanolamine (T.E.A.) 3 M7: of each additive was added to the oil composition HO (see EX. 2). The appearance of the final mix was observed. 5 ml. of the final mix was then added to 95 ml. of water in a stoppered 100 ml. pyrex cylinder and the cylinder rotated. The time taken for complete emulsion to form was noted the emulsibility time. The IP performance test results (See Ex. 2) were also obtained for each sample.
The results are tabulated below:
It can be seen that only the additive according to the invention (the last one in the table) enables a clear oil composition to be obtained coupled with short emulsibility time and acceptable l.P. performance results.
Example 7 Various additives were prepared and incorporated into the oil composition HO (see Ex. 2). The IP test (see Ex. 2) was conducted and the results tabulated. The table shows firstly the results with a series of salts using both benzoic and lauric acids and secondly using only benzoic acid and only laurie acid.
MOLAR RATIO triethanolamine 1P Performance henzoic lauric (mininum emulsion (0.7 mole )+(0.3 mole) "i to pass test) 1.0} only lauric acid 1.5 2.0 present 1.5
2.0 only benzoic acid present .5
The results show the critical nature of the alkanolamine acid ratio. There is a rapid and marked increase in IP Performance in the molar ratio range 1.5 l to 3.0 I, particularly 1.5 l to 2.7 1. Above a ratio of 3 1 there is a rapid decrease in performance.
Although lauric acid alone gives adequate 1P results it has other properties which are disadvantageous Vide Ex. 6 on appearance and emulsibility time.
The foregoing examples show that the anti-rust agent forming the object of the invention is particularly suitable for cmulsifiable metal-working oils. Nevertheless, this anti-rust agent can be used in other applications. Generally speaking, it can be incorporated advantageously in hydrocarbon compositions that are stored or used in contact with a certain quantity of water. For instance, it can be incorporated with fuels of liquid type or motor fuels. It is also possible to embody it in the composition of certain lubricating greases, in lubricating oils for steam engines, in turbine lubricating oils etc.
' 1. An anti-rust additive composition comprising:
a. at least one salt of at least one aliphatic carboxylic acid having 6 to 20 carbon atoms per molecule and at least one alkanolamine.
b. at least one salt of at least one aromatic carhoxylic acid having up to 20 carbon atoms per molecule and at least one alkanolamine. the weight ratio. calculated as free acid, of aromatic acid to aliphatic acid being 0.1 l to 10: l. and
c. at least one alkanolamine in the free state so that,
in total, there are 1.5 to 3.0 equivalents of alkanolamine present per equivalent of acid; the alkanolamines being compounds containing up to carbon atoms per molecule and having the formula a hydroxyalkyl group and X and Y are the same or different groups selected from hydrogen, alkyl and hydroxyalkyl.
2. A composition as claimed in claim I, wherein acids.
6. A composition as claimed in claim 1, wherein the aromatic acid is benzoic acid or p-aminobenzoic acid.
7. A composition as claimed in claim 1. wherein the alkanolamine is selected from monoethanolamine, isopropanolamine, N-dimethylethanolamine, N- diethylethanolamine, N-dimethyl isopropanolamine, N-diethylisopropanolamine. diisopropanolamine. triisopropanolamine. diethanolamine. N- methyldiethanolamine and N-ethyldiethanolamine.
8. A composition as claimed in claim 7, wherein the alkanolamines consist of a mixture of at least two alkanolamines selected from ethanolamine. diethanolamine and triethanolamine 9. A compositionas claimed in claim 7,-wherein the alkanolamines consist of a mixture of at least two alkanolamines selected from isopropanolamine, diisopropanolamine and triisopropanolamine.
10. A composition as claimed in claim. 1, obtained by neutralising at a temperature below 1309C l part by weight of one or more said carboxylic aliphatic acids and 0.l to 10 parts by weight of one or more said aromatic carboxylic acids, with from 1.5 to 3.0 equivalents in total ofthe alkanolamine per equivalent in total of the acids.
11. An emulsifiable composition comprising a composition as claimed in claim 1. further containing a dium alkylbenzene sulphonate emulsifying agent. j
12. The composition of claim 11, further containing a mineral oil base having a viscosity of ID to 200 est at 50C, and wherein the amount of the emulsifier is from 10 to 30 weight percent and the amount of the anti-rust additive composition is from 1 to 5 weight'percent.