Additives for improving the resistance to wear and lacquering of vehicle fuels of the gas oil or bio gas oil type

Abstract

The present disclosure relates to anti-lacquering additives for vehicle fuels of the gas oil or bio gas oil type having a sulphur content less than or equal to 500 ppm by mass. These additives also improve the lacquering resistance of the higher-grade vehicle fuels of gas oil or bio gas oil type having a sulphur content less than or equal to 500 ppm by mass.

1 . Additives for limiting the soap and/or varnish deposits in internal parts of injection systems of engines for (bio) gas oil type vehicle fuels, having a sulphur content less than or equal to 500 ppm by mass, comprising at least 50% by mass of partial polyol ester(s), the polyol esters comprising x ester units, y hydroxylated units and z ether units, x, y and z being integers such that x varies from 1 to 10, y varies from 1 to 10, and z varies from 0 to 6. 
     
     
         2 . Additives according to  claim 1 , wherein the polyol esters are obtained by esterification of fatty acid(s) and linear and/or branched polyols optionally comprising (hetero)cycles of 5 to 6 atoms, bearing hydroxyl functions. 
     
     
         3 . Additives according to  claim 1 , wherein the polyol esters, the ester unit, hydroxylated unit and ether unit distribution is such that x varies from 1 to 4, y varies from 1 to 7 and z varies from 1 to 3. 
     
     
         4 . Additives according to  claim 1 , wherein the polyols R are chosen from the linear polyols comprising more than three hydroxyl functions and the polyols comprising at least one heterocycle of 5 or 6 atoms, optionally substituted by hydroxyl groups, these polyols being able to be used alone or in a mixture. 
     
     
         5 . Additives according to  claim 1 , wherein R is a polyol comprising at least four units presented in formula (I) below;
   H—(OCH 2 ) p —(CHOH) q —(CH 2 OH)  (I)
   
       with p and q being integers, p being equal to or greater than 0, q is greater than 2, these numbers not being able to exceed 10. 
     
     
         6 . Additives according to  claim 1 , wherein R is a polyol comprising at least four units presented in general formula (II) below:
   H—(OCH 2 ) p —(CR1R2) q -(CH 2 OH)  (II)
   
       with p and q being integers, p being equal to or greater than 0, q is greater than 1, these numbers not being able to exceed 5, R1 and R2 are identical or different and represent either the hydrogen atom, or a —CH3 or —C2H5 group, or a —CH2OH group. 
     
     
         7 . Additives according to  claim 1 , wherein R is a polyol comprising at least two heterocycles of 4 or 5 carbon atoms and an oxygen atom, connected by the formation of an acetal bond between a hydroxyl function of each ring, those heterocycles being optionally substituted by hydroxyl groups. 
     
     
         8 . Additives according to  claim 1 , wherein the partial polyol esters are chosen from the partial sorbitan esters, used alone or in a mixture. 
     
     
         9 . Additives according to  claim 1 , wherein the polyols R are chosen from the group comprising erythritol, xylitol, arabitol, ribitol, sorbitol, malitol, isomalitol, lactitol, sorbitan, volemitol, mannitol, pentaerythritol, 2-hydroxymethyl-1,3-propanediol, 1,1,1-tri(hydroxymethyl)ethane, trimethylolpropane and carbohydrates such as sucrose, fructose, maltose, glucose and saccharose. 
     
     
         10 . Additives according to  claim 1 , wherein the partial polyol esters are obtained by reaction of the polyols with at least one fatty acid with a chain length varying from 10 to 24 carbon atoms and/or at least one diacid substituted by at least one polymer, for example poly(iso)butene comprising from 8 to 100 carbon atoms. 
     
     
         11 . Additives according to  claim 10 , wherein the partial polyol esters are chosen from the group constituted by monoesters or diesters obtained from mono acids chosen from the stearic, isostearic, linolenic, oleic, linoleic, behenic, arachidonic, ricinoleic, palmitic, myristic, lauric, capric acids, and mixtures thereof and/or diacids chosen from the alkyl- or alkenylsuccinic, alkyl- or alkenylmaleic acids. 
     
     
         12 . A method for limiting the soap and/or varnish deposits in the internal parts of the injection systems of the engines for the (bio) gas oil vehicle fuels, having a sulphur content less than or equal to 500 ppm by mass the method comprising using the additive as defined in  claim 1 . 
     
     
         13 . The method according to  claim 12 , further comprising incorporating the additive in the (bio) gas oil vehicle fuels for the engines. 
     
     
         14 . The method according to  claim 12 , wherein the engines are direct injection engines. 
     
     
         15 . Compositions of (bio) gas oil vehicle fuel having a sulphur content less than or equal to 500 ppm by mass, comprising:
 at least one additive comprising at least 50% by mass of partial polyol ester(s), the polyol esters comprising x ester units, y hydroxylated units and z ether units, x, y and z being integers such that x varies from 1 to 10, y varies from 1 to 10, and z varies from 0 to 6; and   optionally at least one or more other functional additives.   
     
     
         16 . The compositions of (bio) gas oil vehicle fuel according to  claim 15 , further comprising up to 10% by mass of one or more additional additives. 
     
     
         17 . The compositions according to  claim 15 , wherein the fuel is higher-grade (bio) gas oil vehicle fuel containing at least 50 ppm by mass of deposit reducers/detergents/dispersants, and containing at least 20 ppm by mass of the additive, and optionally at least one or more other functional additives. 
     
     
         18 . The compositions of (bio) gas oil vehicle fuel according to  claim 15  having a mono- and di-ester concentration varying from 20 to 1000 ppm by mass m/m. 
     
     
         19 . (canceled) 
     
     
         20 . (canceled) 
     
     
         21 . A process comprising:
 limiting soap and/or varnish deposits in internal parts of an injection system of an engine for (bio) gas oil vehicle fuel (diesel engine) having a sulphur content less than or equal to 500 ppm by mass; and combustion in the engine of a composition comprising   at least one additive comprising at least 50% by mass of partial polyol ester(s), the polyol esters comprising x ester units, y hydroxylated units and z ether units, x, y and z being integers such that x varies from 1 to 10, y varies from 1 to 10, and z varies from 0 to 6; and   optionally at least one or more other functional additives.   
     
     
         22 . The process according to  claim 21 , wherein the engine is a direct injection engine. 
     
     
         23 . The process according to  claim 21 , further comprising preventing formation of the soap and/or varnish deposits in the internal parts of the injection system of the engine, in order to keep the engine clean. 
     
     
         24 . The process according to  claim 21 , further comprising removing the soap and/or varnish deposits in the internal parts of the injection system of the engine, for a curative action of cleaning up the engine.