Patent Application
20190085259
The present invention relates to lubricant compositions that are especially suitable for the lubrication of turbines or (turbo)compressors that serve to compress chlorine and/or chlorinated products.
The prior art discloses lubricant oils for turbines and compressors. For instance, WO 2011/070141 describes a lubricant oil composition which, as well as a base oil, comprises a succinic acid derivative and an epoxy compound as additives. WO 2008/074760 likewise describes lubricant oil compositions comprising, as additives, an aspartic acid derivative and an epoxy compound or a fatty acid ester of a polyalcohol. Also known are lubricants for turbocompressors or turbines that serve to compress chlorine or chlorinated products. These lubricants usually comprise a highly refined base oil mixture, an additive combination for inhibition of rust and oxidation, an optionally defoamer. For the use of lubricants in compressors with gears, the addition of EP (extreme pressure) additives is known; see W. J. Bartz, Additive für Schmierstoffe [Additives for Lubricants], expert-Verlag, Renningen-Malmsheim 1994.
However, the abovementioned lubricants from the prior art have the disadvantage of low stability to chlorine or chlorinated products and cause corrosion in metals that come into contact with the chlorinated lubricants. Typically, the lubricants from the prior art have a stability toward chlorine of up to 50 ppm at most in the oil. However, this is unsatisfactory because chlorine dissolves in a significantly higher amount in lubricant oils.
In order to prevent the escape of highly toxic chlorine gas in the case of compression of chlorine in compressors, special safety measures are required for the external sealing. For example, bushings for stroke movement are equipped with bellows, and shaft bushings are additionally sealed with barrier gas. Very high demands are made on the integrity and reliability of the valves and inlet guide vane actuators used.
If, in spite of these safety measures described, chlorine gets into a lubricant from the prior art, the lubricant is very quickly oxidized, resulting in aging within a very short time. In addition, acidification of the lubricant is observed. This is manifested in a significant rise in the acid number. By virtue of the simultaneous destruction of the anticorrosion additives present in the lubricant, the protective function of the lubricant with respect to metallic plant materials is lost. The consequence is corrosive attack on bearings and other plant components. The unplanned, corrosion-related deinstallation of plant components leads to plant outages and shutdowns. The costs for the deinstallation of the damaged plant components, the cleaning of the plant and the replacement of the damaged plant components are very high. By virtue of their low resistance to chlorine or chlorinated products, the lubricants from the prior art have just a very short lifetime.
It is therefore an object of the present invention to provide a lubricant composition which is to have improved stability to chlorine and chlorinated products and which is not to cause any corrosion. It is a particular object of the invention to provide a lubricant composition having the abovementioned properties which is suitable for use for lubrication of turbines or (turbo)compressors that serve for compression of chlorine and/or chlorinated products.
This object is achieved by a lubricant composition comprising a base oil, an antihydrolysis component and a rust and oxidation inhibitor.
The present invention therefore relates to lubricant compositions comprising
a) a base oil having a viscosity of 30 to 70 mm2/s at 40° C.,
b) an antihydrolysis component comprising at least one epoxidized C11-C22 fatty acid C1-C12-alkyl ester and/or at least one epoxidized C11-C22 fatty acid glyceride, having an epoxy oxygen content of 1% to 10% by weight, based on the total mass of epoxidized fatty acid C1-C12-alkyl ester and/or epoxidized fatty acid glyceride, and
c) a rust and oxidation inhibitor selected from at least one mono- or poly-C1-C12-alkyl-substituted phenol, at least one arylamine and at least one mono- or polysubstituted triazole and mixtures of two or more of these components.
The viscosity of the hydrocracked oil is understood to mean the kinematic viscosity which is determined with a Stabinger SVM 3000 viscometer, Anton Paar GmbH, at 40° C.
Epoxy oxygen content is understood to mean the percentage proportion by weight of oxygen, based on the total mass of epoxidized compounds.
In one embodiment, the composition of the invention comprises, as component a), a base oil having a viscosity index of ≥120, especially ≥130, the viscosity having been measured at a temperature of 40° C. and 100° C. with a Stabinger SVM 3000 viscometer, Anton Paar GmbH.
In a further embodiment, the base oil comprises at least one oil of quality group III of the base oils according to the classification of the American Petroleum Institute. Group III base oils are understood to mean mineral oils that have been subjected to significant hydrocracking and further deparaffinization. These oils are notable for very good oxidation stability and generally have a viscosity index of more than 120. In a further embodiment, component a) is thus a base oil comprising at least one hydrocracked oil.
In a further embodiment, the base oil of component a) has a viscosity of 40 to 60 mm2/s at 40° C.
The base oil is generally present in the composition in an amount of at least 80% by weight, preferably at least 90% by weight and especially at least 95% by weight, based in each case on the total weight of the composition.
In one embodiment, component a) additionally comprises at least one further base oil component selected from mineral oils, natural oils, hydrogenated polyolefin oils, poly-α-olefins of olefins having 8 to 14 carbon atoms, for example poly-1-decene or oligomers of various olefins having 8 to 14 carbon atoms, polyisobutenes having a molecular weight of 300 to 6000 g/mol, esters of aliphatic dicarboxylic acids, such as azelaic acid, sebacic acid or adipic acid, with a polyglycol having a molecular weight of 500 to 2500 g/mol and a primary C6-C18 alcohol or esters of aliphatic dicarboxylic acids, such as azelaic acid, sebacic acid or adipic acid, with a polyglycol having a molecular weight of 500 to 2500 g/mol and a monocarboxylic acid (complex esters, Ullmann's Encyclopedia of Industrial Chemistry, volume A15, 1990, pages 438-440), C6-C18-alkyl esters of phosphorous acid, C6-C18-alkyl esters of phosphoric acid, diesters of C6-C12-dicarboxylic acids with C6-C18 alcohols, and polyalkyl ether oils which may be perhalogenated, for example perfluorinated, or partly halogenated, for example partly fluorinated. The further base oil component is preferably selected from mineral oils and hydrogenated polyolefin oils.
If present, the amount of further base oil component is in the range from 1% to 20% by weight, based on the total amount of base oil component (a).
The lubricant composition of the invention comprises, as component b), an antihydrolysis component. The antihydrolysis component is present in the composition generally in an amount of 0.05% to 1.5% by weight, preferably 0.05% to 0.9% by weight, based in each case on the total weight of the composition.
In one embodiment of the invention, the fatty acid of the fatty acid alkyl esters and fatty acid glycerides of component b) is selected from the parent fatty acids of natural oils, such as soybean oil, safflower oil, grapeseed oil, mustard oil, coriander oil, linseed oil, colza oil, borage oil, tung oil, evening primrose oil, walnut oil, hemp oil, sunflower oil, olive oil, palm oil, peanut oil, coconut oil, castor oil or fish oil, preferably from the parent fatty acids of soybean oil, linseed oil, colza oil or fish oil.
Examples of fatty acids that may be the parent fatty acids of the abovementioned oils are unsaturated fatty acids having 11 to 22 carbon atoms, for example undecylenoic acid, myristoleic acid, palmitoleic acid, petroselic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, eicosenoic acid, cetoleic acid, erucic acid, linoleic acid, alpha-linolenic acid, gamma-linolenic acid, calendulic acid, punicic acid, alpha-eleostearic acid, beta-eleostearic acid, arachidonic acid, timnodonic acid, cervonic acid or clupanodonic acid.
Among the C1-C12-alkyl esters of the epoxidized fatty acids, preference is given to the C6-C10-alkyl esters, especially the C8-alkyl esters, for example the 2-ethylhexyl esters. C1-C12-Alkyl are understood to mean linear or branched saturated hydrocarbyl radicals having 1 to 12 carbon atoms.
The fatty acid triglycerides mentioned are understood to mean triesters of glycerol with C11-C22 fatty acids. The glycerol may have been triesterified with the identical fatty acid in each case or with two or three different fatty acids.
The epoxidized C11-C22 fatty acid C1-C12-alkyl esters and epoxidized C11-C22 fatty acid glycerides may each be present individually or together as mixtures as a constituent of the antihydrolysis component. Preferably, component b) comprises mixtures of epoxidized C11-C22 fatty acid C1-C12-alkyl esters and epoxidized C11-C22 fatty acid glycerides.
The fatty acid alkyl esters may be present in the form of one fatty acid alkyl ester or of a mixture of two or more fatty acid alkyl esters. The fatty acid glycerides may be present in the form of one fatty acid glyceride or of a mixture of two or more fatty acid glycerides.
The percentage proportion by mass of oxygen, based on the total mass of epoxidized fatty acid C1-C12-alkyl esters and/or epoxidized fatty acid glyceride, in one version of the lubricant composition of the invention, is 3% to 8% by weight.
The C11-C22 fatty acid C1-C12-alkyl esters and epoxidized C11-C22 fatty acid glycerides are prepared in a customary manner, for example by the process described in J. Am. Chem. Soc. 62 (1945), p. 412-414. The epoxy content is determined in a customary manner, for example by the method described in EP 1693359 or DIN 16945.
The lubricant composition of the invention comprises, as component c), a rust and/or oxidation inhibitor. The rust and/or oxidation inhibitor is generally present in the composition in an amount of 0.05% to 2% by weight, preferably 0.05% to 1.0% by weight, based in each case on the total weight of the composition.
In one embodiment of the invention, component (c) comprises at least one mono- or poly-C1-C12-alkyl-substituted phenol or at least one arylamine or at least one mono- or polysubstituted triazole. In a further embodiment of the invention, component (c) comprises at least one mono- or poly-C1-C12-alkyl-substituted phenol and at least one arylamine or at least one mono- or polysubstituted triazole. In a further embodiment of the invention, component (c) comprises at least one arylamine and at least one mono- or polysubstituted triazole. In a further embodiment of the invention, component (c) comprises at least one mono- or poly-C1-C12-alkyl-substituted phenol and at least one arylamine and at least one mono- or polysubstituted triazole.
In one embodiment of the invention, the C1-C12-alkyl-substituted phenol of component c) is selected from C1-C12-alkyl-substituted phenols having sterically demanding substituents, such as isopropyl or tert-butyl. The phenol may be substituted by one substituent or by 2, 3, 4 or 5 substituents. The phenol is preferably di- or trisubstituted.
In one embodiment, the C1-C12-alkyl-substituted phenols are selected from 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 2,4,6-tri-tert-butylphenol, 2-tert-butylphenol, 2,6-diisopropylphenol, 2-methyl-6-tert-butylphenol, 2,4-dimethyl-6-tert-butylphenol and 4-ethyl-2,6-di-tert-butylphenol.
Component c) may comprise one C1-C12-alkyl-substituted phenol or a mixture of two or more C1-C12-alkyl-substituted phenols.
In one embodiment of the invention, component c) comprises at least one arylamine selected from
alkyldiphenylamines of the general formula (I)
where R1, R2, R3 and R4 are the same or different and are hydrogen or C1-C18-alkyl, phenyl-α-naphthylamines of the general formula (II)
where R5 is hydrogen or C1-C18-alkyl and
phenyl-β-naphthylamines of the general formula (III)
where R6 is hydrogen or C1-C18-alkyl.
R1, R2, R3 and R4 may each be hydrogen. Preferably, however, at least one of the radicals is an alkyl group having 1 to 18 carbon atoms, especially 8 to 18 carbon atoms. The alkyl groups may be linear or branched. An alkyl group of this kind may be a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, amyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, isononyl group, decyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, or octadecyl group.
In the general formula (II), R5 is a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. Preferably, R5 is an alkyl group having 1 to 18 carbon atoms, especially 8 to 18 carbon atoms. The alkyl group having 1 to 18 carbon atoms is as defined for R1 to R4.
In the general formula (III), R6 is a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. Preferably, R6 is an alkyl group having 1 to 18 carbon atoms, especially 8 to 18 carbon atoms. The alkyl group having 1 to 18 carbon atoms is as defined for R1 to R4.
Component c) may comprise an alkyldiphenylamine of the general formula (I) alone, or else mixtures of two or more alkyldiphenylamines of the general formula (I). In addition, component c) may comprise a phenyl-alpha-naphthylamine of the general formula (II) alone, or else mixtures of two or more phenyl-alpha-naphthylamines (II). In addition, component c) may comprise a phenyl-beta-naphthylamine of the general formula (III) alone, or else mixtures of two or more phenyl-alpha-naphthylamines (III). Component c) may additionally comprise two or more of the arylamines (I), (II) and (III).
Preferably, mixtures of at least two different arylamines are part of component c).
Component c) may comprise a mono- or polysubstituted triazole.
In one embodiment, the substituted triazole is selected from alkyl- and/or aryl-substituted triazoles, preferably C1-C12-alkyl- and/or C6-C18-aryl-substituted 1,2,3-triazoles and 1,2,4-triazoles.
C1-C12-Alkyl are understood to mean linear, branched or cyclic alkyl radicals having 1 to 12 carbon atoms. C6-C18-Aryl are understood to mean aromatic radicals having 6 to 18 carbon atoms, for example monocyclic aromatic radicals or di- or polycyclic aromatic radicals which may be fused or may be bridged via a chemical bond or a C1-C6-alkyl bridge.
Examples of monosubstituted 1,2,4-triazoles are 1-alkyl- or -aryl-substituted 1H-1,2,4-triazoles, 3-alkyl- or -aryl-substituted 1H-s-triazoles or 4-alkyl- or -aryl-substituted 4H-1,2,4-triazoles. Examples of disubstituted 1,2,4-triazoles are 1,3-alkyl- and/or -aryl-disubstituted 1H-1,2,4-triazoles, 1,5-alkyl- and/or -aryl-disubstituted 1H-1,2,4-triazoles, 3,4-alkyl- and/or -aryl-disubstituted 4H-1,2,4-triazoles or 3,5-alkyl- and/or -aryl-disubstituted s-triazoles. Examples of trisubstituted 1,2,4-triazoles are 1,3,5-alkyl- and/or -aryl-trisubstituted 1H-1,2,4-triazoles or 3,4,5-alkyl- and/or -aryl-trisubstituted 4H-1,2,4-triazoles.
Examples of monosubstituted 1,2,3-triazoles are 1-alkyl- or -aryl-substituted 1H-1,2,3-triazoles or 2-alkyl- or -aryl-substituted 2H-1,2,3-triazoles. Examples of disubstituted 1,2,3-triazoles are 1,4-alkyl- and/or -aryl-disubstituted 1H-1,2,3-triazoles or 2,4-alkyl- and/or -aryl-disubstituted 2H-1,2,3-triazoles. Examples of trisubstituted 1,2,3-triazoles are 1,4,5-alkyl- and/or -aryl-trisubstituted 2H-1,2,3-triazoles or 2,4,5-alkyl- and/or -aryl-trisubstituted 1H-1,2,3-triazoles.
Suitable representatives of component c) are commercially available.
In a further embodiment, the composition of the invention additionally comprises a defoamer. The defoamer may be present in the composition, for example, in an amount of 0.001% to 0.1% by weight, preferably 0.005% to 0.05% by weight, based on the total mass of the composition of the invention.
Useful defoamers suitable as addition to the composition of the invention include homopolymers of C1-C18-alkyl (meth)acrylates, copolymers of at least two C1-C18-alkyl (meth)acrylates or mixtures thereof.
In one embodiment, defoamers used are homopolymers of C1-C8-alkyl (meth)acrylates, copolymers of at least two C1-C8-alkyl (meth)acrylates or mixtures thereof. Alkyl here represents linear or branched alkyl groups, such as methyl, ethyl, propyl, n-butyl, isobutyl, pentyl, hexyl, 2-ethylhexyl, heptyl or octyl groups. Preference is given to the methyl, ethyl, n-butyl and 2-ethylhexyl group. The polymers may also incorporate further monomers such as (meth)acrylic acid, (meth)acrylamide, hydroxy-C2-C6-alkyl (meth)acrylate.
In a preferred embodiment, defoamers used are copolymers of at least two C1-C8-alkyl (meth)acrylates. Examples of defoamers of this kind are copolymers of n-butyl acrylate and/or 2-ethylhexyl acrylate and methyl acrylate and/or ethyl acrylate.
In one embodiment, the defoamer is essentially silicone-free. Essentially silicone-free means that, based on the total mass of the defoamer, less than 1% by weight, preferably 0% by weight, of silicones is present in the defoamer.
Suitable defoamers are commercially available.
In a further embodiment, the composition of the invention additionally comprises an extreme pressure additive. The extreme pressure additive may be present in the composition, for example, in an amount of 0.001% to 0.1% by weight, preferably 0.002% to 0.03% by weight, based on the total mass of the composition of the invention.
Extreme pressure additives suitable as addition to the composition of the invention are generally oil-soluble. Suitable extreme pressure additives are selected, for example, from oil-soluble organic esters of phosphoric acid, oil-soluble organic esters of phosphinic acid, oil-soluble organic esters of phosphonic acid, oil-soluble organic esters of sulfuric acid, oil-soluble organic esters of sulfurous acid, oil-soluble organic esters of sulfonic acid, amine salts of hydroxy-substituted phosphetanes, amine salts of hydroxy-substituted thiophosphetanes, amine salts of partial esters of phosphorous acid and amine salts of partial esters of thiophosphorous acid.
Phosphoric acid, phosphinic acid, phosphonic acid, sulfuric acid, sulfurous acid and sulfonic acid have been esterified here, for example, with alcohols having, for example, 4 to 18 carbon atoms.
The amine salts of hydroxy-substituted phosphetanes, hydroxy-substituted thiophosphetanes, partial esters of phosphorous acid and partial esters of thiophosphorous acid are understood to mean, for example, the C6-C12-alkylamine salts thereof, preferably the octylamine salts thereof.
Partial esters of phosphorous acid and thiophosphorous acid are not fully esterified on all OH groups of the parent free acids. Phosphorous acid and thiophosphorous acid can be partly esterified, for example, with alcohols having, for example, 4 to 18 carbon atoms.
In a preferred embodiment, the composition of the invention comprises an extreme pressure additive selected from alkyl thiophosphate esters.
Examples of alkyl thiophosphate esters are C1-C18-alkyl esters of thiophosphoric acid. The alkyl thiophosphate esters may have three identical alkyl radicals, two or three different.
Suitable extreme pressure additives are commercially available.
In one embodiment, the lubricant composition of the invention comprises one extreme pressure additive or a mixture of two or more different extreme pressure additives.
In a preferred embodiment of the invention, the lubricant composition comprises at least one defoamer and at least one extreme pressure additive, the defoamer and the extreme pressure additive being as defined above.
In a further embodiment, the lubricant composition of the invention comprises
a) the base oil having a viscosity of 30 to 70 mm2/s at 40° C., especially a hydrocracked oil having a viscosity of 40 to 50 mm2/s at 40° C.,
b) 0.05% to 1.5% by weight, especially 0.05% to 0.9% by weight, of the anti-hydrolysis component,
c) 0.05% to 2% by weight, especially 0.05% to 1.0% by weight, of the rust and oxidation inhibitor,
d) optionally 0.001% to 0.1% by weight, especially 0.005% to 0.05% by weight, of a defoamer, and
e) optionally 0.001% to 0.1% by weight, especially 0.002% to 0.03% by weight, of an extreme pressure additive,
based in each case on the total weight of the composition, where components a) to e) are as defined above.
In a further embodiment, the lubricant compositions of the invention do not comprise any succinic ester and/or any aspartic acid derivative, more particularly any aspartic acid acylated on the nitrogen atom or any ester thereof. The succinic esters correspond to the formula
in which X1 and X2 are independently H or alkyl, alkenyl or hydroxyalkyl having 3 to 6 carbon atoms and X3 has 1 to 30 carbon atoms and is alkyl, alkenyl, alkyl with ether bonds or hydroxyalkyl.
The aspartic acid derivatives correspond to the formula
in which X1 and X2 are H, alkyl or hydroxyalkyl having 3 to 6 carbon atoms, X3 is alkyl having 1 to 30 carbon atoms, alkyl with ether bonds or hydroxyalkyl and X4 is saturated or unsaturated radicals having carboxylic acid groups, especially alkyl or alkenyl radicals, having 1 to 30 carbon atoms, alkenyl or hydroxyalkyl.
The lubricant compositions of the invention have the advantage of high stability toward chlorine or chlorinated products. More particularly, the lubricant compositions of the invention are stable to chlorine contents of more than 50 ppm up to 2000 ppm. Thus, the lubricant compositions of the invention are suitable for the lubrication of turbines or (turbo)compressors that serve to compress chlorine and/or chlorinated products.
The invention further provides for the use of the lubricant compositions of the invention for the lubrication of turbines or (turbo)compressors.
The lubricant compositions of the invention are particularly suitable for use for lubrication of turbines or (turbo)compressors that serve for compression of chlorine and/or chlorinated products.
The lubricant compositions of the invention are obtained, for example, by mixing (using a suitable stirrer) the abovementioned components in a suitable apparatus, for example a mixing tank. The compositions can be applied to the parts to be lubricated, for example bushings for stroke movements of a turbine or a (turbo)compressor, for example, by spraying and/or spreading the compositions on the parts mentioned.
The examples which follow serve to elucidate the invention without restricting it.
The following components were introduced into a mixing tank in the ratios specified and mixed therein to give a lubricant composition:
To determine the anticorrosion properties, a method customary in the lubricants industry for determination of corrosion according to DIN ISO 7120 was modified. Rather than water and oil, a lubricant composition with 2000 ppm of added chlorine was initially charged as test fluid according to example 1 and the test specimens used were left at 60° C. while stirring (1000 rpm) for 24 hours. The test specimens used were either the steel test specimens described in DIN ISO 7120 or test specimens of white metal, which is typically used as bearing metal in compressors. After 24 hours, the stirring operation was ended and the test specimens were removed from the test fluid. After they had dripped dry, the test specimen was rinsed with cleaning solution and the degree of corrosion was assessed according to the DIN ISO 7120 classification. A test specimen is considered to have undergone some degree of rusting when any spot of rust or strip of rust is visible. If both test specimens are free of rust, the lubricant composition has passed the test.
It has been found that, with the lubricant composition according to example 1, even with a concentration of 2000 ppm of chlorine in the oil, no corrosion is observed, i.e. the lubricant composition has passed the test.
Furthermore, the lubricant composition was not discolored, nor were any precipitates observed. The lubricant composition has thus been found to be stable even to a chlorine content of 2000 ppm.
| Number | Date | Country | Kind |
|---|---|---|---|
| 15186863.5 | Sep 2015 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/072719 | 9/23/2016 | WO | 00 |
