LUBRICATING COMPOSITION COMPRISING AN ANTI-KNOCK COMPOUND

Abstract

The disclosure relates to the use of a lubricating composition including at least one base oil and at least one organic compound for reducing, or even eliminating, knocking in the engine of vehicles, preferably motor vehicles.

Description

FIELD

The present invention relates to the field of lubricants, more particularly to the field of engine lubricants. More particularly, the present invention relates to the use of a lubricant composition for reducing knock in a vehicle engine, said lubricant composition comprising at least one base oil and at least one organic anti-knock compound. The lubricant composition according to the invention thus makes it possible to reduce or even eliminate knock in a vehicle engine, preferably a motor vehicle engine, while retaining good lubrication properties.

The present invention also relates to a lubrication process implementing this composition. The present invention also relates to a process for reducing or even eliminating knock in a vehicle engine, preferably a motor vehicle engine, using this lubricant composition. The present invention also relates to the use of an organic compound in a lubricant composition for reducing or eliminating knock in a vehicle engine, preferably a motor vehicle engine. The present invention also relates to the use of an additive concentrate-type composition comprising at least one organic compound for reducing or even eliminating knock in a vehicle engine, preferably a motor vehicle engine, utilizing said organic compound.

BACKGROUND

Knock is a phenomenon which occurs in a vehicle spark-ignition engine, and more particularly in a motor vehicle spark-ignition engine, and which is due to the auto-ignition of fuel upstream of the flame front in the combustion chamber. This auto-ignition propagates at very high speed in the combustion chamber and causes high-frequency vibrations of the gaseous mass and thermal overload of the engine which may potentially lead to serious mechanical failure. The solutions commonly used by engine manufacturers to prevent this phenomenon, such as reducing the ignition advance, significantly reduce the power output of spark-ignition engines.

Furthermore, following the establishment of the Kyoto protocol, new environmental protection standards have required the motor vehicle industry to construct vehicles having reduced pollutant emissions. However, there is today a tendency to decrease the size of vehicle engines, which must however function at higher power output levels in order to optimize fuel economy savings. However, these savings may be affected very easily by the knock phenomenon.

The combustion phenomenon is a compromise between the propagation speed of the flame front from the spark plug and the auto-ignition delay of the fuel. When the latter is too short, knock occurs in the areas distant from the spark plug and most often close to the piston and the cylinder. A lubricant, and more particularly an engine lubricant, is used within cylinders to reduce friction and risks of wear. The proximity of the engine lubricant to the areas in which knock appears opens up the possibility of interaction between it and the combustion. Thus, lubricants making it possible to attenuate or even to reduce engine knock have been sought.

U.S. Pat. Nos. 2,763,613 and 2,898,359 have in particular described the use of anti-knock compounds selected from organometallic compounds, and more particularly ferrocene-type compounds in a lubricant composition. Furthermore, document WO2004/101717 describes the use of manganese-based organometallic compounds in a lubricant composition for reducing the knock phenomenon in an engine. However, the use of such organometallic compounds promotes deposits in the combustion chamber and can thus lead to abnormal combustion, such as preignition, which can cause significant mechanical malfunction(s). Moreover, they can present a risk to human health.

Document WO2004/104717 further describes various organic compounds of the alcohol, ester or ether type that can be used in a lubricant composition for reducing the knock phenomenon in an engine. Furthermore, U.S. Pat. No. 8,129,320 describes oils selected from esters of trimellitic acid or also alkyl naphthalene-type compounds, as well as the use thereof in a lubricant composition for reducing the knock phenomenon in an engine. However, the mass content of these oils in the lubricant is at least 50%, which can strongly reduce performance(s) in terms of reduction of friction or resistance to oxidation of the lubricant composition.

Thus, there remains a need to have available organic compounds that can reduce or eliminate the knock phenomenon in an engine and that can be easily formulated in a lubricant composition. An objective of the present invention is thus to provide organic compounds as well as a lubricant composition comprising these organic compounds which overcome all or part of the above-mentioned drawbacks. Another objective of the present invention is to provide a composition making it possible to reduce or even to eliminate knock in an engine and the formulation of which is easy to implement. Another objective of the present invention is to provide a lubricant composition for reducing or even eliminating engine knock while avoiding the occurence of deposits in the combustion chamber. Another objective of the present invention is to provide a lubrication process for reducing or even eliminating engine knock.

SUMMARY

An object of the invention is the use of a lubricant composition for reducing knock in a vehicle engine, preferably a motor vehicle engine, said lubricant composition comprising:

at least one base oil,

at least one compound of formula (I):

wherein:

• • X—Y represents:

• • R1 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR17 group, an —NR18R19 group;
  • R2 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR20 group, an —NR21 R22 group;
  • R3 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR23 group, an —NR24R25 group;
  • R4 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR26 group, an —NR27R28 group;
  • R5 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR29 group, an —NR30R31 group;
  • R6 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR32 group, an —NR33R34 group;
  • R7 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR35 group, an —NR36R37 group;
  • R8 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR38 group, an —NR39R40 group;
  • R9 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR41 group, an —NR42R43 group;
  • R10 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR44 group, an —NR45R46 group;
  • R11 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR47 group, an —NR48R49 group;
  • R12 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR50 group, an —NR51 R52 group;
  • R13 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR53 group, an —NR54R55 group;
  • R14 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR56 group, an —NR57R58 group;
  • R15 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR59 group, an —NR60R61 group;
  • R16 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR62 group, an —NR63R64 group;
  • R17, R20, R23, R26, R29, R32, R35, R38, R41, R44, R47, R50, R53, R56, R59 and R62, identical or different, represent independently a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms;
  • R18, R19, R21, R22, R24, R25, R27, R28, R30, R31, R33, R34, R36, R37, R39, R40, R42, R43, R45, R46, R48, R49, R51, R52, R54, R55, R57, R58, R60, R61, R63 and R64, identical or different, represent independently a hydrogen atom or a saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 3 carbon atoms.

Surprisingly, the applicant noted that the presence of a compound of formula (I) as defined above in a lubricant composition allows the lubricant composition, when utilized in an engine, to reduce or even to eliminate the knock phenomenon in the engine. Thus, the present invention makes it possible to formulate lubricant compositions having both good stability and good properties of reducing or even eliminating the knock phenomenon when utilized in an engine.

Advantageously, the lubricant compositions used according to the invention have good properties of reducing or even eliminating the knock phenomenon when utilized in an engine without needing to add a high content of anti-knock compound in the lubricant composition. Advantageously, the lubricant compositions used according to the invention have good properties of reducing or eliminating the knock phenomenon when utilized in an engine without needing to add other anti-knock additives thereto, and particularly no anti-knock additives selected from organometallic compounds. Advantageously, the lubricant compositions used according to the invention have good properties of reducing or even eliminating the knock phenomenon when utilized in an engine and the formulation of which is easy to implement. Advantageously, the lubricant compositions used according to the invention have good properties of reducing or even eliminating the knock phenomenon when utilized in an engine while making it possible to reduce or even to eliminate the risk of deposits in the combustion chamber.

In an embodiment of the invention, the lubricant composition essentially consists of:

at least one base oil,

at least one compound of formula (I):

wherein:

• • X—Y represents:

• • R1 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR17 group, an —NR18R19 group;
  • R2 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR20 group, an —NR21 R22 group;
  • R3 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR23 group, an —NR24R25 group;
  • R4 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR26 group, an —NR27R28 group;
  • R5 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR29 group, an —NR30R31 group;
  • R6 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR32 group, an —NR33R34 group;
  • R7 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR35 group, an —NR36R37 group;
  • R8 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR38 group, an —NR39R40 group;
  • R9 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR41 group, an —NR42R43 group;
  • R10 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR44 group, an —NR45R46 group;
  • R11 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR47 group, an —NR48R49 group;
  • R12 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR50 group, an —NR51 R52 group;
  • R13 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR53 group, an —NR54R55 group;
  • R14 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR56 group, an —NR57R58 group;
  • R15 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR59 group, an —NR60R61 group;
  • R16 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR62 group, an —NR63R64 group;
  • R17, R20, R23, R26, R29, R32, R35, R38, R41, R44, R47, R50, R53, R56, R59 and R62, identical or different, represent independently a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms;
  • R18, R19, R21, R22, R24, R25, R27, R28, R30, R31, R33, R34, R36, R37, R39, R40, R42, R43, R45, R46, R48, R49, R51, R52, R54, R55, R57, R58, R60, R61, R63 and R64, identical or different, represent independently a hydrogen atom or a saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 3 carbon atoms.

The invention also relates to an engine oil comprising a lubricant composition as defined above. The invention also relates to the use of a lubricant composition as defined above for lubricating vehicle engines, preferentially motor vehicle engines. The invention also relates to a process for lubricating a vehicle engine, preferably a motor vehicle engine, said process comprising at least one step of bringing into contact a mechanical part of the engine with a lubricant composition as defined above. The invention also relates to a process for reducing or even eliminating knock in a vehicle engine, preferentially a motor vehicle engine, comprising at least one step of bringing into contact a mechanical part of the vehicle engine with a lubricant composition as defined above. The invention also relates to the use of a compound of formula (I) as defined above in a lubricant composition for reducing or even eliminating knock in engines, preferentially motor vehicle engines.

The invention also relates to the use of an additive concentrate-type composition in a lubricant composition comprising at least one base oil for reducing or even eliminating knock in a vehicle engine, preferentially a motor vehicle engine, said additive concentrate-type composition comprising:

at least one compound of formula (I):

wherein:

• • X—Y represents:

• • R1 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR17 group, an —NR18R19 group;
  • R2 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR20 group, an —NR21 R22 group;
  • R3 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR23 group, an —NR24R25 group;
  • R4 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR26 group, an —NR27R28 group;
  • R5 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR29 group, an —NR30R31 group;
  • R6 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR32 group, an —NR33R34 group;
  • R7 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR35 group, an —NR36R37 group;
  • R8 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR38 group, an —NR39R40 group;
  • R9 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR41 group, an —NR42R43 group;
  • R10 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR44 group, an —NR45R46 group;
  • R11 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR47 group, an —NR48R49 group;
  • R12 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR50 group, an —NR51 R52 group;
  • R13 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR53 group, an —NR54R55 group;
  • R14 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR56 group, an —NR57R58 group;
  • R15 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR59 group, an —NR60R61 group;
  • R16 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR62 group, an —NR63R64 group;
  • R17, R20, R23, R26, R29, R32, R35, R38, R41, R44, R47, R50, R53, R56, R59 and R62, identical or different, represent independently a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms;
  • R18, R19, R21, R22, R24, R25, R27, R28, R30, R31, R33, R34, R36, R37, R39, R40, R42, R43, R45, R46, R48, R49, R51, R52, R54, R55, R57, R58, R60, R61, R63 and R64, identical or different, represent independently a hydrogen atom or a saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 3 carbon atoms,

at least one additive selected from detergents, friction modifiers, anti-wear additives, dispersants, extreme-pressure additives, antioxidants, viscosity index improver polymers, pour point depressants, anti-foaming agents, thickeners and mixtures thereof.

DETAILED DESCRIPTION

The percentages indicated below correspond to percentages by mass of active ingredient. The lubricant composition comprises at least one compound of formula (I):

wherein:

• • X—Y represents:

• • R1 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR17 group, an —NR18R19 group;
  • R2 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR20 group, an —NR21 R22 group;
  • R3 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR23 group, an —NR24R25 group;
  • R4 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR26 group, an —NR27R28 group;
  • R5 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR29 group, an —NR30R31 group;
  • R6 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR32 group, an —NR33R34 group;
  • R7 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR35 group, an —NR36R37 group;
  • R8 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR38 group, an —NR39R40 group;
  • R9 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR41 group, an —NR42R43 group;
  • R10 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR44 group, an —NR45R46 group;
  • R11 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR47 group, an —NR48R49 group;
  • R12 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR50 group, an —NR51 R52 group;
  • R13 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR53 group, an —NR54R55 group;
  • R14 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR56 group, an —NR57R58 group;
  • R15 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR59 group, an —NR60R61 group;
  • R16 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR62 group, an —NR63R64 group;
  • R17, R20, R23, R26, R29, R32, R35, R38, R41, R44, R47, R50, R53, R56, R59 and R62, identical or different, represent independently a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms;
  • R18, R19, R21, R22, R24, R25, R27, R28, R30, R31, R33, R34, R36, R37, R39, R40, R42, R43, R45, R46, R48, R49, R51, R52, R54, R55, R57, R58, R60, R61, R63 and R64, identical or different, represent independently a hydrogen atom or a saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 3 carbon atoms.

Thus, the compound of formula (I) as defined above does not comprise metal nor any metallic derivative. The compound of formula (I) as defined above is not an organometallic compound.

In an embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ia):

wherein R1, R2, R3, R4, R5 and R6 are as defined above.

In a preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ia) wherein:

R5 represents a hydrogen atom,

R1, R2, R3, R4 and R6 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ia) wherein:

R6 represents a hydrogen atom,

R1, R2, R3, R4 and R5 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ia) wherein:

R5 and R6 represent a hydrogen atom,

R1, R2, R3 and R4 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ia) wherein:

R1, R5 and R6 represent a hydrogen atom,

R2, R3 and R4 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ia) wherein:

R2, R5 and R6 represent a hydrogen atom,

R1, R3 and R4 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ia) wherein:

R3, R5 and R6 represent a hydrogen atom,

R1, R2 and R4 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ia) wherein:

R4, R5 and R6 represent a hydrogen atom,

R1, R2 and R3 are as defined above.

In a more preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ia) wherein R1, R2, R3, R4, R5 and R6 represent a hydrogen atom. As an example of a compound of formula (Ia) used according to the invention, mention may be made of the cyclopentadiene of formula:

In another embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ib):

wherein R1, R2, R3, R4, R7, R8, R9 and R10 are as defined above.

In a preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ib) wherein:

R7 represents a hydrogen atom,

R1, R2, R3, R4, R8, R9 and R10 are as defined above.

In a preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ib) wherein:

R8 represents a hydrogen atom,

R1, R2, R3, R4, R7, R9 and R10 are as defined above.

In a preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ib) wherein:

R9 represents a hydrogen atom,

R1, R2, R3, R4, R7, R8 and R10 are as defined above.

In a preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ib) wherein:

R10 represents a hydrogen atom,

R1, R2, R3, R4, R7, R8 and R9 are as defined above.

In a preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ib) wherein:

R7, R8, R9 and R10 represent a hydrogen atom,

R1, R2, R3 and R4 are as defined above.

In a preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ib) wherein:

R1, R7, R8, R9 and R10 represent a hydrogen atom,

R2, R3 and R4 are as defined above.

In a preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ib) wherein:

R2, R7, R8, R9 and R10 represent a hydrogen atom,

R1, R3 and R4 are as defined above.

In a preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ib) wherein:

R3, R7, R8, R9 and R10 represent a hydrogen atom,

R1, R2 and R4 are as defined above.

In a preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ib) wherein:

R4, R7, R8, R9 and R10 represent a hydrogen atom,

R1, R2 and R3 are as defined above.

In a more preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ib) wherein R1, R2, R3, R4, R7, R8, R9 and R10 represent a hydrogen atom.

As an example of a compound of formula (Ib) used according to the invention, mention may be made of the indene of formula:

In another embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ic):

wherein R1, R2, R3, R4, R11, R12, R13, R14, R15 and R16 are as defined above.

In a preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ic) wherein:

R15 represents a hydrogen atom,

R1, R2, R3, R4, R11, R12, R13, R14 and R16 are as defined above.

In a preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ic) wherein:

R16 represents a hydrogen atom,

R1, R2, R3, R4, R11, R12, R13, R14 and R15 are as defined above.

In a preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ic) wherein:

R15 and R16 represent a hydrogen atom,

R1, R2, R3, R4, R11, R12, R13 and R14 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ic) wherein:

R11, R15 and R16 represent a hydrogen atom,

R1, R2, R3, R4, R12, R13 and R14 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ic) wherein:

R12, R15 and R16 represent a hydrogen atom,

R1, R2, R3, R4, R11, R13 and R14 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ic) wherein:

R13, R15 and R16 represent a hydrogen atom,

R1, R2, R3, R4, R11, R12 and R14 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ic) wherein:

R14, R15 and R16 represent a hydrogen atom,

R1, R2, R3, R4, R11, R12 and R13 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ic) wherein:

R11, R12, R13, R14, R15 and R16 represent a hydrogen atom,

R1, R2, R3 and R4 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ic) wherein:

R1, R11, R12, R13, R14, R15 and R16 represent a hydrogen atom,

R2, R3 and R4 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ic) wherein:

R2, R11, R12, R13, R14, R15 and R16 represent a hydrogen atom,

R1, R3 and R4 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ic) wherein:

R3, R11, R12, R13, R14, R15 and R16 represent a hydrogen atom,

R1, R2 and R4 are as defined above.

In another preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ic) wherein:

R4, R11, R12, R13, R14, R15 and R16 represent a hydrogen atom,

R1, R2 and R3 are as defined above.

In a more preferred embodiment of the invention, the lubricant composition comprises at least one compound of formula (Ic) wherein R1, R2, R3, R4, R11, R12, R13, R14, R15 and R16 represent a hydrogen atom. As an example of a compound of formula (Ic) used according to the invention, mention may be made of the dicyclopentadiene of formula:

In an embodiment of the invention, the mass content of the compound of formula (I) ranges from 0.5 to 25%, preferably from 1 to 20%, advantageously from 5 to 15% relative to the total mass of the lubricant composition. In an embodiment of the invention, the compound of formula (I) may be in a pure form. By “pure form” is meant, according to the invention, that the compound of formula (I) consists of a single component and does not comprise another component other than the compound of formula (I) or is not combined with another compound.

In another embodiment of the invention, the compound of formula (I) may be encapsulated. Thus, the compound of formula (I) may be present in the form of a capsule or a microcapsule comprising a minimum content of the compound of formula (I), this minimum content being selected in such a way that the mass content of the compound of formula (I) ranges from 0.5 to 25%, preferably from 1 to 20%, advantageously from 5 to 15% relative to the total mass of the lubricant composition.

The capsules or microcapsules comprising the compound of formula (I) may be selected from any type of capsules or microcapsules known to the person skilled in the art. The capsules or microcapsules may in particular consist of a polymer shell selected from polyurethanes, polyureas, polystyrenes, polyesters, polyamides or copolymers thereof, polyacrylonitriles, vinyl resins, formaldehyde-based resins or aminoplast resins. In a preferred embodiment of the invention, the compound (I) will be released outside the capsules or microcapsules when the capsules or microcapsules are subjected to physical and chemical stresses, and more particularly when the capsules or microcapsules are subjected to high temperatures, for example temperatures above 150° C. as may be encountered in areas close to the piston, or when the capsules or microcapsules are subjected to high shear stresses, which is generally the case in an engine, corresponding for example to values from 10 to 100 million reciprocal seconds (s⁻¹), or when the capsules or microcapsules are subjected to variations of the acidity or the basicity of the surrounding medium, and more particularly to variations of acidity as may be produced in the piston/sleeve zone. Examples of capsules or microcapsules that may be used in the present invention are described especially in document WO2010/134044, U.S. Patent Publication No. 2013/0146009 and document WO2014/046876.

In another embodiment of the invention, the compound (I) may be released by volatilization. The volatilization of the compound of formula (I) may be implemented particularly by adjusting the distillation curve of the lubricant composition. As an example, mention may be made of the use of a compound of formula (I) which is more volatile than the rest of the lubricant composition and which makes it possible to extract the compound of formula (I) in the areas subjected to temperatures above the boiling point of the compound of formula (I) but below the boiling point of the lighter components of the rest of the lubricant composition. In another embodiment of the invention, the compound of formula (I) may be synthesized in situ in the lubricant composition.

Base Oil

The lubricant compositions used according to the invention may contain any type of mineral, synthetic or natural, animal or vegetable lubricating base oil adapted to their use. The base oil(s) used in the lubricant compositions used according to the present invention may be oils of mineral or synthetic origin belonging to Groups I through V according to the categories defined in the API classification (or their equivalents according to the ATIEL classification) as summarized below, alone or in mixture.

	TABLE 1
	Saturates	Sulfur	Viscosity
	content	content	index (VI)
Group I	<90%	>0.03%	80 ≦ VI < 120
Mineral oils
Group II	≧90%	≦0.03%	80 ≦ VI < 120
Hydrocracked oils
Group III	≧90%	≦0.03%	≧120
Hydrocracked or
hydroisomerized oils
Group IV	Polyalphaolefins (PAO)
Group V	Esters and other bases not included
	in Groups I to IV bases

The mineral base oils used according to the invention include all type of bases obtained by atmospheric and vacuum distillation of crude oil, followed by refining operations such as solvent extraction, deasphalting, solvent dewaxing, hydrotreating, hydrocracking and hydroisomerization, hydrofinishing. The base oils of the lubricant compositions used according to the invention may also be synthetic oils, such as certain esters of carboxylic acids and of alcohols, or polyalphaolefins. The polyalphaolefins used as base oils are, for example, obtained from monomers having from 4 to 32 carbon atoms (for example octene, decene), and a viscosity at 100° C. ranging between 1.5 and 15 cSt according to the ASTM D445 standard. Their weight average molecular weight typically lies between 250 and 3000 according to the ASTM D5296 standard. Mixtures of synthetic and mineral oils may also be employed.

There is no limitation as to the employment of one lubricating base or another to produce the lubricant compositions used according to the invention, if it is only that they must have properties, in particular of viscosity, viscosity index, sulfur content, oxidation resistance, adapted to use in a gearbox, in particular in a motor vehicle gearbox, in particular in a manual gearbox. In an embodiment of the invention, the lubricating bases constitute at least 50% by mass relative to the total mass of the lubricant composition, preferentially at least 60%, or at least 70%. Typically, they constitute between 75 and 99.9% by mass relative to the total mass of the lubricant compositions used according to the invention.

In a preferred embodiment of the invention, the lubricant compositions comprise mineral bases of Group I and/or III, or synthetic bases of Group IV according to the API classification. In another preferred embodiment of the invention, the lubricant compositions have a kinematic viscosity at 100° C. measured according to the ASTM D445 standard ranging from 3 to 25 cSt, preferably from 5 to 22 cSt, advantageously from 5 to 13 cSt. In another preferred embodiment of the invention, the lubricant compositions have a viscosity index (VI) of 130 or above, preferentially of 140 or above, advantageously of 150 or above measured according to the ISO 2909 standard.

Other Additives

The lubricant compositions used according to the invention may also further contain at least one additive selected from detergents, anti-wear additives, extreme-pressure additives, dispersants, pour point depressants, anti-foaming agents, thickeners, viscosity index improver polymers and mixtures thereof. The anti-wear and extreme-pressure additives protect friction surfaces by forming a protective film adsorbed on these surfaces. A wide variety of anti-wear additives exist, but the category most often used in lubricant compositions, in particular for engine oil, is that of phosphosulfurized additives such as metal alkylthiophosphates, in particular zinc alkylthiophosphates, and more specifically zinc dialkyldithiophosphates (ZnDTP). Amine phosphates are also anti-wear additives which may be employed in the lubricant compositions used according to the invention. However, the phosphorus provided by these additives acts as a poison in motor vehicle catalytic systems because these additives produce ash. These effects may be minimized by partially substituting the amine phosphates with additives not providing phosphorus, such as, for example, polysulfides, in particular sulfurized olefins. In an embodiment, particularly for an engine application, the anti-wear and extreme-pressure additives may be present in the lubricant composition in amounts ranging from 0.01 to 6% by mass, preferentially from 0.05 to 4%, preferentially from 0.1 to 2% relative to the total mass of the lubricant composition.

The friction-modifying additive may be a compound which provides metal elements or may be an ash-free compound. Among compounds which provide metal elements, mention may be made of complexes of transition metals such as Mo, Sb, Sn, Fe, Cu, Zn, W the ligands of which may be hydrocarbon compounds containing oxygen, nitrogen, sulfur or phosphorus atoms, and in particular molybdenum dithiocarbamates. The ash-free friction modifiers are of organic origin and may be selected from monoesters of fatty acids and polyols, alkoxylated amines, alkoxylated fatty amines, fatty epoxides, borated fatty epoxides; fatty amines or glycerol esters of fatty acids. By “fatty” is meant, within the meaning of the present invention, a hydrocarbon group comprising from 10 to 24 carbon atoms. In an embodiment, the friction-modifying additive may be present in amounts ranging from 0.01 to 5% by mass, preferentially from 0.1 to 2% relative to the total mass of the lubricant composition.

The antioxidant additives slow down the degradation of the lubricant compositions in service, in particular engine oils in service, degradation which may in particular result in the formation of deposits, the presence of sludge, or an increase in the viscosity of the lubricant composition, in particular of the engine oil. The antioxidant additives act in particular as radical inhibitors or hydroperoxide destroyers. Among the antioxidants commonly employed, mention may be made of phenolic- or amine-type antioxidants and phosphosulfurized antioxidants. Some of these antioxidants, for example phosphosulfurized antioxidants, may produce ash. The phenolic antioxidants may be ash-free or in the form of neutral or basic metal salts.

The antioxidant agent may be selected in particular from sterically hindered phenols, sterically hindered phenol esters and sterically hindered phenols comprising a thioether bridge, diphenylamines, diphenylamines substituted by at least one C1-C12 alkyl group, N,N′ dialkyl aryl diamines and combinations thereof. By “sterically hindered phenol” is meant, within the meaning of the present invention, a compound comprising a phenol group of which at least one vicinal carbon of the carbon bearing the alcohol function is substituted by at least one C1-C10 alkyl group, preferably a C1-C6 alkyl group, preferably a C4 alkyl group, preferably by the tert-butyl group. The amine compounds are another antioxidant class which may be used, optionally in combination with phenolic antioxidants. Typical examples are aromatic amines of formula R25R26R27N, wherein R25 represents an aliphatic group or an optionally substituted aromatic group, R26 represents an optionally substituted aromatic group, R27 represents a hydrogen atom, an alkyl group, an aryl group or a group of formula R28S(O)_zR29, wherein R28 represents an alkylene group or an alkenylene group, R29 represents an alkyl group, an alkenyl group or an aryl group and z represents an integer equal to 0, 1 or 2. Sulfurized alkyl phenols or the alkali and alkaline-earth metal salts thereof may also be used as antioxidants. Another antioxidant class is that of copper compounds, for example copper thio- or dithiophosphates, salts of copper and carboxylic acids, copper dithiocarbamates, sulfonates, phenates, acetylacetonates. Copper(I) and (II), succinic acid or anhydride salts may also be used.

The lubricant composition used according to the invention may contain any type of antioxidant additives known to the person skilled in the art. Advantageously, ash-free antioxidants are used. In an embodiment, the lubricant composition used according to the invention may comprise from 0.5 to 2% of at least one antioxidant additive by mass relative to the total mass of the lubricant composition.

The detergent additives reduce in particular the formation of deposits on the surface of the metal parts by dissolving oxidation and combustion by-products. The detergents that may be used in the lubricant composition used according to the invention are well-known to the person skilled in the art. The detergents commonly used in the formulation of lubricant compositions may be anionic compounds comprising a long lipophilic hydrocarbon chain and a hydrophilic head. The associated cation is typically a metal cation of an alkali or alkaline-earth metal. The detergents are preferentially selected from alkali or alkaline-earth metal salts of carboxylic acids, sulfonates, salicylates, naphthenates, as well as phenolate salts. The alkali and alkaline-earth metals are preferentially calcium, magnesium, sodium or barium. These metal salts may contain the metal in an approximately stoichiometric amount or in excess (in an amount greater than the stoichiometric amount). In the latter case, these detergents are referred to as overbased detergents. The excess metal providing the detergent with its overbased character is present in the form of oil-insoluble metal salts, for example carbonate, hydroxide, oxalate, acetate, glutamate, preferentially carbonate. In an embodiment, the lubricant composition used according to the invention may comprise from 0.5 to 4% by mass of detergent, relative to the total mass of the lubricant composition.

The flow point depressant additives improve in particular the low-temperature behavior of the lubricant compositions, by slowing down the formation of paraffin crystals. As examples of flow point depressant additives, mention may be made of alkyl polymethacrylates, polyacrylates, polyarylamides, polyalkylphenols, polyalkylnaphthalenes, alkylated polystyrenes.

In an embodiment, the lubricant composition used according to the invention may further comprise at least one dispersant. The dispersants may be selected from the groups formed by Mannich bases, succinimides and derivatives thereof, particularly borated succinimides. In an embodiment, the lubricant composition used according to the invention may comprise from 0.2 to 10% by mass of dispersants relative to the total mass of the lubricant composition. The viscosity index improver polymers may be selected from polymer esters, ethylene-based copolymers, particularly ethylene/propylene copolymers and ethylene/α-olefin copolymers, homopolymers or copolymers of styrene, butadiene or isoprene, hydrogenated or not hydrogenated, polymethacrylates (PMA). In an embodiment, the lubricant composition used according to the invention may comprise from 1 to 15% by mass of viscosity index improver polymers relative to the total mass of the lubricant composition. The anti-foaming additives may be selected from polyacrylates or silicone compounds and derivatives thereof, and particularly polysiloxanes.

In an embodiment of the invention, the lubricant composition comprises:

from 75 to 99.5% of at least one base oil,

from 0.5 to 25% of at least one compound of formula (I).

In another embodiment of the invention, the lubricant composition comprises:

from 75 to 99% of at least one base oil,

from 0.5 to 25% of at least one compound of formula (I),

from 0.5 to 5% of at least one other additive.

In another embodiment of the invention, the lubricant composition consists essentially of:

75 to 99.5% of at least one base oil,

0.5 to 25% of at least one compound of formula (I).

In another embodiment of the invention, the lubricant composition consists essentially of:

75 to 99% of at least one base oil,

0.5 to 25% of at least one compound of formula (I),

0.5 to 5% of at least one other additive.

All the characteristics and preferences presented above for the base oil, the compound of formula (I) and the additional additive also apply to the lubricant compositions above. In an embodiment of the invention, the lubricant composition is not an emulsion. In another embodiment of the invention, the lubricant composition is anhydrous.

An object of the invention in also an engine oil comprising a lubricant composition used according to the invention. All the characteristics and preferences presented above for the lubricant composition also apply to the engine oil according to the invention. In an embodiment of the invention, the engine oil may be of 0W-16, 0W-20 and 5W-30 grade according to the SAEJ300 classification, characterized by a kinematic viscosity at 100° C. (KV100) ranging from 5.6 to 12.5 cSt measured according to the ASTM D445 international standard. In another embodiment of the invention, the engine oil may be characterized by a viscosity index, calculated according to the ISO 2909 international standard, of 130 or above, preferably of 150 or above. To formulate an engine oil, base oils having a sulfur content below 0.3%, for example mineral oils of Group III, and sulfur-free synthetic bases, preferentially of Group IV, or mixtures thereof, may advantageously be used.

An object of the invention is also the use of a lubricant composition as defined above for lubricating vehicle engines, preferentially motor vehicle engines, advantageously spark-ignition motor vehicle engines. An object of the invention is also the use of a lubricant composition as defined above for reducing the fuel consumption of vehicles, in particular of motor vehicles. All the characteristics and preferences presented above for the lubricant composition also apply to the uses above.

An object of the invention is a process for lubricating a vehicle engine, preferably a motor vehicle engine, advantageously a spark-ignition motor vehicle engine, said process comprising at least one step of bringing into contact a mechanical part of the engine with a lubricant composition as defined above. An object of the invention is also a process for reducing or even eliminating knock in a vehicle engine, preferentially a motor vehicle engine, advantageously a spark-ignition motor vehicle engine, comprising at least one step of bringing into contact a mechanical part of the vehicle engine with a lubricant composition as defined above. The reduction or even the elimination of knock in an engine may be evaluated by any method known to the person skilled in the art. The reduction or even the elimination of knock in an engine by the use of a lubricant composition may in particular be evaluated by measuring the evolution of the power output of the engine and by measuring the evolution of the spark-advance parameter in the presence of the lubricant composition.

An object of the invention is also a process for reducing the fuel consumption of a vehicle, particularly of a motor vehicle, comprising at least one step of contacting a mechanical part of the vehicle engine with a lubricant composition as defined above. All the characteristics and preferences presented above for the lubricant composition also apply to the processes above.

The vehicles may comprise a two- or four-stroke spark-ignition internal combustion engine. The engines may be gasoline engines intended to be supplied with gasoline or natural gas. By “conventional gasoline” is meant, within the meaning of the present invention, engines which are supplied with a fuel obtained after refining of an oil of mineral origin (such as petroleum for example). The engines may also be gasoline engines modified to be supplied with a fuel based on oils derived from renewable materials, such as alcohol-based fuels. The vehicles may be light vehicles such as automobiles and motorcycles. The vehicles may also be heavy vehicles or construction vehicles.

An object of the invention is also the use of a compound of formula (I) as defined above in a lubricant composition for reducing or even eliminating knock in engines, preferentially motor vehicle engines, advantageously spark-ignition motor vehicle engines. All the characteristics and preferences presented above for the compound of formula (I) also apply to the use above.

An object of the invention is also the use of an additive concentrate-type composition in a lubricant composition comprising at least one base oil for reducing or even eliminating knock in a vehicle engine, preferentially a motor vehicle engine, said additive concentrate-type composition comprising:

at least one compound of formula (I):

wherein:

• • X—Y represents:

• • R1 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR17 group, an —NR18R19 group;
  • R2 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR20 group, an —NR21 R22 group;
  • R3 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR23 group, an —NR24R25 group;
  • R4 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR26 group, an —NR27R28 group;
  • R5 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR29 group, an —NR30R31 group;
  • R6 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR32 group, an —NR33R34 group;
  • R7 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR35 group, an —NR36R37 group;
  • R8 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR38 group, an —NR39R40 group;
  • R9 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR41 group, an —NR42R43 group;
  • R10 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR44 group, an —NR45R46 group;
  • R11 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR47 group, an —NR48R49 group;
  • R12 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR50 group, an —NR51 R52 group;
  • R13 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR53 group, an —NR54R55 group;
  • R14 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR56 group, an —NR57R58 group;
  • R15 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR59 group, an —NR6OR61 group;
  • R16 represents a hydrogen atom, a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms, an —OR62 group, an —NR63R64 group;
  • R17, R20, R23, R26, R29, R32, R35, R38, R41, R44, R47, R50, R53, R56, R59 and R62, identical or different, represent independently a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 10 carbon atoms;
  • R18, R19, R21, R22, R24, R25, R27, R28, R30, R31, R33, R34, R36, R37, R39, R40, R42, R43, R45, R46, R48, R49, R51, R52, R54, R55, R57, R58, R60, R61, R63 and R64, identical or different, represent independently a hydrogen atom or a saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 3 carbon atoms,

at least one additive selected from detergents, friction modifiers, anti-wear additives, dispersants, extreme-pressure additives, antioxidants, viscosity index improver polymers, pour point depressants, anti-foaming agents, thickeners and mixtures thereof.

All the characteristics and preferences presented above for the compound of formula (I) and for the additional additive also apply to the additive concentrate-type composition above. In an embodiment of the invention, at least one base oil may be added to the additive concentrate-type composition used according to the invention in order to obtain a lubricant composition used according to the invention.

Claims

1. A method for reducing knock in a vehicle engine, the method comprising bringing a mechanical part of the vehicle engine into contact with a lubricant composition comprising: at least one base oil;at least one compound of formula (I):

2. The method according to claim 1 wherein the lubricant composition comprises a compound of formula (Ia):

3. The method according to claim 2 wherein R5 and R6 represent a hydrogen atom.

4. The method according to claim 2 wherein R1, R2, R3 and R4 represent a hydrogen atom.

5. The method according to claim 1 wherein the lubricant composition comprises a compound of formula (Ib):

6. The method according to claim 5 wherein R7, R8, R9 and R10 represent a hydrogen atom.

7. The method according to claim 5 wherein R1, R2, R3 and R4 represent a hydrogen atom.

8. The method according to claim 1 wherein the lubricant composition comprises a compound of formula (Ic):

9. The method according to claim 8 wherein R15 and R16 represent a hydrogen atom.

10. The method according to claim 8 wherein R11, R12, R13 and R14 represent a hydrogen atom.

11. The method according to claim 8 wherein R1, R2, R3 and R4 represent a hydrogen atom.

12. The method according to claim 1 wherein the mass content of the compound of formula (I) ranges from 0.5 to 25% relative to the total mass of the lubricant composition.

13. The method according to claim 1, wherein the lubricant composition further comprises at least one additive selected from detergents, friction modifiers, dispersants, anti-wear additives, extreme-pressure additives, antioxidants, viscosity index improver polymers, pour point depressants, anti-foaming agents, thickeners and mixtures thereof.

14. A method for reducing knock in a vehicle engine, the method comprising: a) adding at least one base oil to an additive concentrate-type composition in order to obtain a lubricant composition;b) bringing a mechanical part of the vehicle engine into contact with the lubricant composition, the additive concentrate-type composition comprising:at least one compound of formula (I):