Additive composition for engine oil

Abstract

The disclosure relates to an additive composition including: (a) at least one compound including an azole heterocycle, (b) at least one alkylbenzene or alkylnaphthalene sulphonate not surbased with an alkali or alkaline-earth metal, (c) at least one carbodiimide, and (d) at least one antioxidant The disclosure also relates to the use thereof as additive composition for engine oil.

1 . An additive composition comprising:
 (a) at least one compound comprising an azole heterocycle selected from the group consisting of diazoles, triazoles, diazoles wherein the azole heterocycle of which comprises a sulphur atom and triazoles wherein the azole heterocycle of which comprises a sulphur atom;   (b) at least one non overbased alkylbenzene or alkylnaphthalene sulphonate of an alkali or alkaline-earth metal, the alkyl substituent or substituents of which comprise from 7 to 12 carbon atoms;   (c) at least one carbodiimide of formula X—N═C═N—Y, where X and Y are, independently of each other, hydrocarbon radicals comprising from 8 to 60 carbon atoms, of formula (I):   
       
         
           
           
               
               
           
         
       
       where R1 is selected from the group consisting of an aliphatic group, a monoaromatic group, an aliphatic group substituted, a monoaromatic group substituted comprising from 2 to 20 carbon atoms; 
       R2 is selected from the group consisting of either hydrogen, an aliphatic group, a monoaromatic group, an aliphatic group substituted, a monoaromatic group, comprising from 2 to 20 carbon atoms; 
       R3 is selected from the group consisting of either hydrogen, an aliphatic group, a monoaromatic group, an aliphatic group substituted, a monoaromatic group substituted, a monoaromatic group, condensed, comprising from 2 to 20 carbon atoms; and
 (d) at least one antioxidant chosen from the secondary amines the nitrogen atom of which is linked to at least one aryl group, or from the phenols substituted on at least one of their ortho positions, by alkyl groups comprising from 1 to 10 carbon atoms and their dimers. 
 
     
     
         2 . The additive composition according to  claim 1  comprising, as compound (c), at least one carbodiimide where X and Y each bear 2 or 3 substituents, in the ortho, or ortho and para positions with respect to the carbodiimide group, and where at least one of these substituents is a branched aliphatic chain having at least 3 carbon atoms or a cycloaliphatic substituent having from 5 to 6 carbon atoms. 
     
     
         3 . The additive composition according to  claim 1  comprising, as compound (a), at least one benzotriazole of formula (V): 
       
         
           
           
               
               
           
         
         where R6 and R7 are, independently of each other, linear, branched or cyclic hydrocarbon groups having from 1 to 30 carbon atoms, which can contain an oxygen, sulphur or nitrogen atom. 
       
     
     
         4 . The additive composition according to  claim 1  comprising, as compound (b), at least one neutral dialkylbenzene or dialkylnaphthalene sulphonate of an alkali or alkaline-earth metal, the alkyl substituents of which comprise from 7 to 12 carbon atoms. 
     
     
         5 . The additive composition according to  claim 1  wherein compound (b) has a BN, measured according to the standard ASTM D2892, less than 20 mg of KOH/gram. 
     
     
         6 . The additive composition according to  claim 1  wherein the secondary amines present as compound (d) are chosen from the secondary amines of formula R8-NH—R9, where R8 and R9 are, independently of each other:
 a phenyl group, a phenyl group substituted by alkyl or alkenyl groups comprising from 1 to 10 carbon atoms; 
 a naphthyl group, a naphthyl group substituted by alkyl or alkenyl groups comprising from 1 to 10 carbon atoms 
 or R8 is a phenyl group, and R9 forms, with the nitrogen atom of the amine function and the R8 ring, a C6 heterocycle or a C6 heterocycle substituted by alkyl groups. 
 
     
     
         7 . The additive composition according to  claim 6  where the secondary amines present as compound (d) are chosen from the group consisting of diphenylamines, diphenylamines having their phenyl groups substituted in the ortho position by alkyl or alkenyl groups comprising from 1 to 10 carbon atoms, non substituted phenylnaphthylamine, phenylnaphthyl amines substituted by at the most 2 alkyl or alkenyl groups comprising from 1 to 10. 
     
     
         8 . The additive composition according to  claim 1  comprising at least one secondary amine as compound (d). 
     
     
         9 . The additive composition according to  claim 1  where the percentages by mass [a], [b], [c] and [d] of compounds (a), (b), (c) and (d) are present in a synergistically effective ratio, and/or comply with:
 [c]:[a] comprised between 10 and 100, 
 [c]:[b] is comprised between 1 and 10; and 
 [c]:[d] is comprised between 1 and 10. 
 
     
     
         10 . A lubricant composition for engines comprising an additive composition further comprising:
 (a) at least one compound comprising an azole heterocycle selected from the group consisting of diazoles, triazoles, diazoles wherein the azole heterocycle of which comprises a sulphur atom and triazoles wherein the azole heterocycle of which comprises a sulphur atom;   (b) at least one non overbased alkylbenzene or alkylnaphthalene sulphonate of an alkali or alkaline-earth metal, the alkyl substituent or substituents of which comprise from 7 to 12 carbon atoms;   (c) at least one carbodiimide of formula X—N═C═N—Y, where X and Y are, independently of each other, hydrocarbon radicals comprising from 8 to 60 carbon atoms, of formula (I):   
       
         
           
           
               
               
           
         
       
       where R1 is selected from the group consisting of an aliphatic group a monoaromatic group, an aliphatic group substituted, a monoaromatic group substituted comprising from 2 to 20 carbon atoms; 
       R2 is selected from the group consisting of either hydrogen, an aliphatic group, a monoaromatic group, an aliphatic group substituted, a monoaromatic group, comprising from 2 to 20 carbon atoms; 
       R3 is selected from the group consisting of either hydrogen, an aliphatic group, a monoaromatic group, an aliphatic group substituted, a monoaromatic group substituted, a monoaromatic group, condensed, comprising from 2 to 20 carbon atoms;
 (d) at least one antioxidant chosen from the secondary amines the nitrogen atom of which is linked to at least one aryl group, or from the phenols substituted on at least one of their ortho positions, by alkyl groups comprising from 1 to 10 carbon atoms and their dimers; 
 one or more base oils, and at least one friction modifier, comprising:
 (i) at least one organometallic friction modifier chosen from the group consisting of the organomolybdenum or organotungstate compounds, 
 
 
       and/or
 (ii) at least one organic friction modifier chosen from the group consisting of fatty amines, fatty alcohols, fatty acids, fatty acid esters glycerol esters and their derivatives. 
 
     
     
         11 . The lubricant composition according to  claim 10  comprising between 0.8% and 5% by mass of friction modifiers. 
     
     
         12 . The lubricant composition according to  claim 10  comprising between 1 and 1.5% by mass of organic friction modifiers. 
     
     
         13 . The lubricant composition according to  claim 10  comprising between 0 and 0.5% by mass of organometallic friction modifier. 
     
     
         14 . The lubricant composition according to  claim 10 , where the quantity of additive composition is such that compound (c) represents from 0.5 to 4% by mass of said lubricant composition. 
     
     
         15 . A method of reducing the corrosiveness vis-à-vis copper, lead and tin, measured according to ASTM D6594, of an engine oil, comprising adding an additive composition to an engine oil, the engine oil at least one friction modifier comprising:
 (i) at least one organometallic friction modifier chosen from the organomolybdenum or organotungstate compounds, 
 
       and/or
 (ii) at least one organic friction modifier chosen from the group consisting of fatty amines, fatty alcohols, fatty acids, fatty acid esters, glycerol esters and their derivatives; 
 the additive composition comprising: 
 (a) at least one compound comprising an azole heterocycle selected from the group consisting of diazoles, triazoles, diazoles wherein the azole heterocycle of which comprises a sulphur atom and triazoles wherein the azole heterocycle of which comprises a sulphur atom; 
 (b) at least one non overbased alkylbenzene or alkylnaphthalene sulphonate of an alkali or alkaline-earth metal, the alkyl substituent or substituents of which comprise from 7 to 12 carbon atoms; 
 (c) at least one carbodiimide of formula X—N═C═N—Y, where X and Y are, independently of each other, hydrocarbon radicals comprising from 8 to 60 carbon atoms, of formula (I): 
 
       
         
           
           
               
               
           
         
       
       where R1 is selected from the group consisting of an aliphatic group a monoaromatic group, an aliphatic group substituted, a monoaromatic group substituted comprising from 2 to 20 carbon atoms; 
       R2 is selected from the group consisting of either hydrogen, an aliphatic group, a monoaromatic group, an aliphatic group substituted, a monoaromatic group, comprising from 2 to 20 carbon atoms; 
       R3 is selected from the group consisting of either hydrogen, an aliphatic group, a monoaromatic group, an aliphatic group substituted, a monoaromatic group substituted, a monoaromatic group, condensed, comprising from 2 to 20 carbon atoms;
 (d) at least one antioxidant chosen from the secondary amines the nitrogen atom of which is linked to at least one aryl group, or from the phenols substituted on at least one of their ortho positions, by alkyl groups comprising from 1 to 10 carbon atoms and their dimers. 
 
     
     
         16 . (canceled) 
     
     
         17 . The additive composition according to  claim 6  wherein the secondary amines present as compound (d) are chosen from the secondary amines of formula R8-NH—R9, where R8 and R9 are, independently of each other:
 a phenyl group substituted in the para position of the amine function by alkyl or alkenyl groups comprising from 1 to 10 carbon atoms, 
 a naphthyl group substituted by alkyl or alkenyl groups comprising from 1 to 10 carbon atoms. 
 
     
     
         18 . The additive composition according to  claim 1  wherein in the formula (V) R6 and R7 are, independently of each other, linear, branched or cyclic hydrocarbon groups having from 2 to 20 carbon atoms, which can contain an oxygen, sulphur or nitrogen atom. 
     
     
         19 . The lubricant composition for engines according to  claim 10 , wherein the glycerol esters are selected from the group consisting of glycerol mono-, di- or triheptanoate, oleate, stearate, isostearate, linoleate, caprylate, the citrates, tartrates, malates, lactates, madelates, glycolates, hydroxypropionates, hydroxglutarates, and their derivatives. 
     
     
         20 . The lubricant composition for engine according to  claim 10 , comprising between 1 and 1.5% by mass of organic friction modifiers and between 0 and 0.5% by mass of organometallic friction modifer. 
     
     
         21 . The method according to  claim 15 , wherein the glycerol esters are selected from the group consisting of as glycerol mono-, di- or triheptanoate, oleate, stearate, isostearate, linoleate, caprylate, the citrates, tartrates, malates, lactates, mandelates, glycolates, hydroxypropionates, hydroxyglutarates, and their derivates.