EP3099721B1 - Lubricating compositions comprising thermoassociative and exchangeable copolymers - Google Patents

Description

FIELD OF THE INVENTION

The present invention relates to a composition resulting from the mixture of at least one lubricating oil, at least one random copolymer A1, and at least one compound A2 comprising at least two boronic ester functions; the random copolymer A1 results from the copolymerization of at least one first monomer M1 carrying diol functions and at least one second monomer M2 of chemical structure different from that of the monomer M1.

The invention also relates to the use of this composition for lubricating a mechanical part.

The field of the present invention is that of lubricants.

TECHNICAL BACKGROUND

Lubricating compositions are compositions applied between the surfaces, in particular metal surfaces, of moving parts. They reduce the friction and wear between two parts in contact and in motion relative to each other. They also serve to dissipate some of the thermal energy generated by this friction. Lubricating compositions form a protective film between the surfaces of the parts to which they are applied.

The compositions used for the lubrication of mechanical parts generally consist of a base oil and additives. The base oil, in particular of petroleum or synthetic origin, exhibits variations in viscosity with the temperature being varied.

Indeed, when the temperature of a base oil increases, its viscosity decreases and when the temperature of the base oil decreases, its viscosity increases. However, the thickness of the protective film is proportional to the viscosity, so also depends on the temperature. A composition has good lubricating properties if the thickness of the protective film remains substantially constant regardless of the conditions and the duration of use of the lubricant.

In an internal combustion engine, a lubricating composition may be subjected to external or internal temperature changes. The external temperature changes are due to changes in ambient air temperature, such as temperature variations between summer and winter, for example. The internal temperature changes result from the implementation of the motor. The temperature of an engine is lower during its start-up phase, especially in cold weather, than during prolonged use. Therefore, the thickness of the protective film may vary in these different situations.

There is therefore a need to have a lubricating composition having good lubricating properties and whose viscosity is little subject to temperature variations.

It is known to add additives improving the viscosity of a lubricating composition. These additives have the function of modifying the rheological behavior of the lubricating composition. They promote a substantially constant viscosity over a temperature range at which the lubricant composition is used. For example, these additives limit the decrease in the viscosity of the lubricant composition when the temperature rises or limit the increase in the viscosity of the lubricating composition as the temperature decreases.

The viscosity-improving additives (or viscosity index improvers) currently used are polymers such as polyalpha-olefins, polymethyl methacrylates, copolymers resulting from the polymerization of an ethylenic monomer and an alpha-olefin. . These polymers are of high molecular weight. In general, the contribution of these polymers to the control of the viscosity is all the more important that their molecular weight is high.

However, the high molecular weight polymers have the disadvantage of having a low permanent shear strength compared to polymers of the same nature but of smaller size.

However, a lubricant composition is subjected to significant shear stresses, particularly in internal combustion engines, where the friction surfaces have a very small gap and the pressures exerted on the parts are high. These shear stresses on the high molecular weight polymers cause cuts in the macromolecular chains. The polymer thus degraded no longer has thickening properties, and the viscosity drops irreversibly. This loss of permanent shear strength therefore leads to a degradation of the lubricating properties of the lubricant composition.

The polymers of the prior art, in particular PMMA (polymethylmethacrylates) have a rheo-thickening behavior. At a high shear rate, the PMMA chain breaks. This results in the formation of two molecules having approximately half the molar weight of the initial PMMA. The total hydrodynamic volume of these two small molecules is lower than that of the initial PPMA, which results in a lower viscosity contribution and results in a reduction in viscosity.

Ethylene-alphaolefin copolymers having a high ethylene content are viscosity improvers and are shear stable. However, these polymers have the disadvantage of aggregating in the compositions containing them and lead to extremely viscous lubricating compositions, such as gels. This aggregation generally occurs at ambient conditions or during cooling.

Also, the aim of the applicant is to formulate new lubricating compositions whose viscosity is better controlled with respect to the lubricant compositions of the prior art. In particular, it aims to provide new rheological additives, which when introduced into a base oil, have an inverted behavior with respect to a modification of the temperature with respect to the behavior of the base oil and the rheological additives of polymer type of the prior art.

This objective is achieved thanks to new rheological additives that can associate, possibly forming a gel, and exchange in a thermoreversible manner. Unlike the base oil which becomes liquefied as the temperature increases, the additives of the present invention have the advantage of thickening the medium in which they are dispersed as the temperature increases.

This characteristic results from the combined use of two particular compounds, a copolymer bearing diol functions and a compound comprising boronic ester functions.

It is known from the document WO2013147795 polymers of which at least one monomer comprises boronic ester functions. These polymers are used for the manufacture of electronic devices, especially for devices which are desired to obtain a flexible user interface. These polymers are also used as synthesis intermediate. They make it possible to functionalize the polymers by coupling with luminescent groups, electron-carrying groups, etc. The coupling of these groups is carried out by conventional organic chemical reactions involving the boron atom, such as, for example, Suzuki coupling. However, no other use of these polymers in the field of lubricating compositions, nor an association with other compounds is contemplated.

It is known from the document US4,401,797 a copolymer resulting from the copolymerization of a methyl methacrylate monomer (MMA) and a glyceryl methacrylate monomer optionally protected by a boronic ester (namely butylboronic acid glyceryl methacrylate (BBA-GMA)). This copolymer forms a hydrogel in the presence of water and is used for the manufacture of contact lenses. However, no other use of this copolymer in the field of lubricating compositions, nor a combination via chemical bonds exchangeable with other compounds is contemplated.

The document EP0570073 discloses an additive which improves the viscosity index of a lubricating composition in which it is added. This additive is a copolymer resulting from the polymerization of 1- (methacryloylethoxy) -4,4,6-trimethyl-dioxaborinane and a linear alkyl methacrylate (C ₁₂ -C ₁₈ ). This additive belongs to the family of borate compounds which can be represented by the general formula B (OR) ₃ with R an alkyl or aryl group. This additive does not belong to the family of boronate compounds which may be represented by the general formula RB (OR) ₂ with R an alkyl or aryl group. This additive can not associate with other compounds via exchangeable chemical bonds.

Unexpectedly, the Applicant has observed that at low temperature, the polydiol copolymer of the invention is not or only slightly crosslinked by the compounds comprising boronic ester functions. When the temperature increases, the diol functions of the copolymer react with the boronic ester functions of the compound comprising them by a transesterification reaction. Polydiol random copolymers and compounds comprising boronic ester functions then bind together and can be exchanged. Depending on the functionality of the polydiols and compounds comprising boronic ester functions, as well as the composition of the mixtures, a gel may form in the base oil. When the temperature decreases again, the boronic ester linkages between the polydiol random copolymers and the compounds comprising them break; the composition loses its gelled character if necessary.

The Applicant has also set itself the objective of formulating new rheology additives which are more stable in shear with respect to the compounds of the prior art.

This objective is achieved thanks to the new rheological additives that can combine and crosslink in a thermoreversible way. In contrast to the polymers of the prior art, it has been found that the molar weight of the copolymers of the invention is not or little changed when a high shear rate is applied. The copolymers of the invention therefore have the advantage of being more stable to shear stresses.

SUMMARY OF THE INVENTION

• au moins une huile lubrifiante,
• au moins un copolymère statistique A1 et au moins un composé A2 comprenant au
  moins deux fonctions esters boroniques, le composé A2 pouvant s'associer et établir des liens chimiques covalents de type ester boronique avec le copolymère statistique A1 de manière thermoréversible;
  ∘ le copolymère statistique A1 résultant de la copolymérisation :
  • ▪ d'au moins un premier monomère M1 de formule générale (I)
    
    dans laquelle :
    • R₁ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃ ;
    • x est un nombre entier allant de 2 à 18;
    • y est un nombre entier égal à 0 ou 1;
    • X₁ et X₂, identiques ou différents, sont choisis parmi le groupe formé par l'hydrogène, le tétrahydropyranyle, le méthyloxyméthyle, le ter-butyle, le benzyle, le triméthylsilyle et le t-butyle diméthylsilyle ;
      ou bien
    • X₁ et X₂ forment avec les atomes d'oxygène un pont de formule suivante
      
      dans laquelle:
      • les étoiles (*) symbolisent les liaisons aux atomes d'oxygène,
      • R'₂ et R"₂, identiques ou différents, sont choisis parmi le groupe formé par l'hydrogène et un alkyle en C₁-C₁₁, de préférence le méthyle;
      ou bien
    • X₁ et X₂ forment avec les atomes d'oxygène un ester boronique de formule suivante
      
      dans laquelle :
      • les étoiles (*) symbolisent les liaisons aux atomes d'oxygène,
      • R"'₂ est choisi parmi le groupe formé par un aryle en C₆-C₁₈, un aralkyle en C₇-C₁₈ et alkyle en C₂-C₁₈, de préférence un aryle en C₆-C₁₈;
  • ▪ avec au moins un second monomère M2 de formule générale (II-A) :
    
    dans laquelle :
    • R₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃,
    • R₃₁ est choisi parmi le groupe formé par un aryle en C₆-C₁₈, un aryle en C₆-C₁₈ substitué par un groupement R'₃, -C(O)-O-R'_3; -O-R'₃, -S-R'₃ et -C(O)-N(H)-R'₃ avec R'₃ un groupe alkyle en C₁-C₃₀.

Thus, the subject of the invention is a novel composition resulting from the mixture of:

• at least one lubricating oil,
• at least one random copolymer A1 and at least one compound A2 comprising at least
  minus two boronic ester functions, the compound A2 being able to associate and establish covalent chemical bonds of boronic ester type with the statistical copolymer A1 thermoreversibly;
  ∘ the statistical copolymer A1 resulting from the copolymerization:
  • At least one first monomer M1 of general formula (I)
    
    in which :
    • R ₁ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ ;
    • x is an integer from 2 to 18;
    • y is an integer equal to 0 or 1;
    • X ₁ and X ₂ , identical or different, are chosen from the group formed with hydrogen, tetrahydropyranyl, methyloxymethyl, tert-butyl, benzyl, trimethylsilyl and t-butyl dimethylsilyl;
      or
    • X ₁ and X ₂ form with the oxygen atoms a bridge of following formula
      
      in which:
      • the stars (*) symbolize the bonds to the oxygen atoms,
      • R ' ₂ and R " ₂ , which are identical or different, are chosen from the group formed by hydrogen and a C ₁ -C ₁₁ alkyl, preferably methyl;
      or
    • X ₁ and X ₂ form with the oxygen atoms a boronic ester of following formula
      
      in which :
      • the stars (*) symbolize the bonds to the oxygen atoms,
      • R "_'2 is selected from the group consisting of a C ₆ -C ₁₈ aralkyl, C ₇ -C ₁₈ alkyl and C ₂ -C _18, preferably C ₆ -C _18;
  • With at least one second monomer M2 of general formula (II-A):
    
    in which :
    • R ₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ ,
    • R ₃₁ is selected from the group consisting of a C ₆ -C ₁₈ aryl, C ₆ -C ₁₈ substituted by a group R _3, -C (O) -O-R _'3; -O-R ' ₃ , -S-R' ₃ and -C (O) -N (H) -R ' ₃ with R' ₃ a C ₁ -C ₃₀ alkyl group.

In a variant, the random copolymer A1 results from the copolymerization of at least one monomer M1 with at least two monomers M2 having different R ₃₁ groups.

dans laquelle :

• R₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃,
• R"₃₁ est un groupe alkyle en C₁-C₁₄,

et l'autre monomère M2 du copolymère statistique A1 a pour formule générale (II-A2) :

dans laquelle :

• R₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃.
• R"'₃₁ est un groupe alkyle en C₁₅-C₃₀.

Preferably, one of the monomers M2 of the random copolymer A1 has the formula General (II-A1):

in which :

• R ₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ ,
• R " ₃₁ is a C ₁ -C ₁₄ alkyl group,

and the other monomer M2 of the random copolymer A1 has the general formula (II-A2):

in which :

• R ₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ .
• R "_'31 is a C ₁₅ -C ₃₀ alkyl group.

dans laquelle :

• w₁ et w₂, identiques ou différents sont des nombres entiers choisis entre 0 et 1,
• R₄, R₅, R₆ et R₇, identiques ou différents sont choisis parmi le groupe formé par l'hydrogène et un groupe hydrocarboné ayant de 1 à 24 atomes de carbone, de préférence entre 4 et 18 atomes de carbone, de préférence entre 6 et 14 atomes de carbone ;
• L est un groupement de liaison divalent et est choisi parmi le groupe formé par un aryle en C₆-C₁₈, un aralkyle en C₆-C₁₈ et une chaîne hydrocarbonée en C₂-C₂₄.

In one variant of the composition, the compound A2 is a compound of formula (III):

in which :

• w ₁ and w ₂ , identical or different, are integers selected from 0 to 1,
• R ₄ , R ₅ , R ₆ and R ₇ , which are identical or different, are chosen from the group formed by hydrogen and a hydrocarbon group having from 1 to 24 carbon atoms, preferably from 4 to 18 carbon atoms, preferably between 6 and 14 carbon atoms;
• L is a divalent linking group and is selected from the group consisting of a C ₆ -C ₁₈ aralkyl, C ₆ -C ₁₈ hydrocarbon chain and a C ₂ -C _24.

• ▪ d'au moins un monomère M3 de formule (IV) :
  
  dans laquelle :
  • t est un nombre entier égal à 0 ou 1 ;
  • u est un nombre entier égal à 0 ou 1 ;
  • M et R₈ sont des groupements de liaison divalent, identiques ou différents, sont choisis parmi le groupe formé par un aryle en C₆-C₁₈, un aralkyle en C₇-C₂₄ et alkyle en C₂-C₂₄, de préférence un aryle en C₆-C₁₈,
  • X est une fonction choisie parmi le groupe formé par -O-C(O)-, -C(O)-O-, -C(O)-N(H)-, -N(H)-C(O)-, -S-, -N(H)-, -N(R'₄)- et -O- avec R'₄ une chaîne hydrocarbonée comprenant de 1 à 15 atomes de carbone;
  • R₉ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃ ;
  • R₁₀ et R₁₁ identiques ou différents choisis parmi le groupe formé par l'hydrogène et un groupe hydrocarboné ayant de 1 à 24 atomes de carbone, de préférence entre 4 et 18 atomes de carbone, de préférence entre 6 et 14 atomes de carbone,
• ▪ avec au moins un second monomère M4 de formule générale (V) :
  
  dans laquelle :
  • R₁₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃,
  • R₁₃ est choisi parmi le groupe formé par un aryle en C₆-C₁₈, un aryle en C₆-C₁₈ substitué par un groupement R'₁₃, -C(O)-O-R'_13; -O-R'₁₃, -S-R'₁₃ et -C(O)-N(H)-R'₁₃ avec R'₁₃ un groupe alkyle en C₁-C₂₅.

In another variant of the composition, the compound A2 is a random copolymer resulting from the copolymerization:

• At least one monomer M3 of formula (IV):
  
  in which :
  • t is an integer equal to 0 or 1;
  • u is an integer equal to 0 or 1;
  • M and R ₈ are divalent linking groups, which may be identical or different, are chosen from the group formed by a C ₆ -C ₁₈ aryl, a C ₇ -C ₂₄ aralkyl and a C ₂ -C ₂₄ alkyl, preferably a C ₆ -C ₁₈ aryl,
  • X is a function chosen from the group formed by -OC (O) -, -C (O) -O-, -C (O) -N (H) -, -N (H) -C (O) -, -S-, -N (H) -, -N (R ' ₄ ) - and -O- with R' ₄ a hydrocarbon chain comprising from 1 to 15 carbon atoms;
  • R ₉ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ ;
  • R ₁₀ and R ₁₁ identical or different selected from the group consisting of hydrogen and a hydrocarbon group having 1 to 24 carbon atoms, preferably between 4 and 18 carbon atoms, preferably between 6 and 14 carbon atoms,
• With at least one second monomer M4 of general formula (V):
  
  in which :
  • R ₁₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ ,
  • R ₁₃ is selected from the group consisting of a C ₆ -C ₁₈ aryl, C ₆ -C ₁₈ substituted by a group R _13, -C (O) -O-R _'13; -O-R _'13 , -S-R' ₁₃ and -C (O) -N (H) -R _'13 with R' ₁₃ a C ₁ -C ₂₅ alkyl group.

• la chaîne formée par l'enchaînement des groupes R₁₀, M, X et (R₈)_u avec u un nombre entier égal à 0 ou 1, du monomère de formule générale (IV) présente un nombre total d'atomes de carbone compris entre 8 et 38, de préférence entre 10 et 26 atomes de carbone;
• les chaînes latérales du copolymère A2 ont une longueur moyenne supérieure à 8 atomes de carbone, de préférence allant de 11 à 16 atomes de carbone ;
• le copolymère statistique A2 a un pourcentage molaire de monomère de formule (IV) dans ledit copolymère allant de 0,25 à 20%, de préférence de 1 à 10% ;
• le copolymère statistique A2 a un degré de polymérisation moyen en nombre allant de 50 à 1500, de préférence de 80 à 800 ;
• les chaînes latérales du copolymère statistique A1 ont une longueur moyenne allant de 8 à 20 atomes de carbone, de préférence de 9 à 15 atomes de carbone ;
• le copolymère statistique A1 a un pourcentage molaire de monomère M1 de formule (I) dans ledit copolymère allant de 1 à 30%, de préférence allant de 5 à 25, de manière plus préférée allant de 9 à 21% ;
• le copolymère statistique A1 a un degré de polymérisation moyen allant de 100 à 2000, de préférence de 150 à 1000 ;
• l'huile lubrifiante est choisie parmi les huiles du groupe I, du groupe II, du groupe III, du groupe IV, du groupe V de la classification API et l'un de leur mélange ;
• la composition comprend en outre un additif fonctionnel choisi parmi le groupe formé par les détergents, les additifs anti-usure, les additifs extrême pression, les antioxydants supplémentaires, les polymères améliorant l'indice de viscosité, les améliorants de point d'écoulement, les anti-mousses, les additifs anticorrosion, les épaississants, les dispersants, les modificateurs de frottements et leurs mélanges ;
• le ratio massique dans la composition entre le copolymère statistique A1 et le composé A2 (ratio A1/A2) va de 0,001 à 100, de préférence de 0,05 à 20, de manière encore plus préférée de 0,1 à 10, de manière encore plus préférée de 0,2 à 5 ;
• la somme des masses du copolymère statistique A1 et du composé A2 dans la composition va de 0,5 à 20% par rapport à la masse totale de la composition lubrifiante et la masse d'huile lubrifiante va de 80% à 99,5% par rapport à la masse totale de la composition lubrifiante.

Preferably, the compositions described above comprise one or more of the following characteristics, taken separately or in combination:

• the chain formed by the linking of the groups R ₁₀ , M, X and (R ₈ ) _u with u an integer equal to 0 or 1, of the monomer of general formula (IV) has a total number of carbon atoms included between 8 and 38, preferably between 10 and 26 carbon atoms;
• the side chains of the copolymer A2 have an average length greater than 8 carbon atoms, preferably ranging from 11 to 16 carbon atoms;
• the random copolymer A2 has a molar percentage of monomer of formula (IV) in said copolymer ranging from 0.25 to 20%, preferably from 1 to 10%;
• the random copolymer A2 has a number-average degree of polymerization ranging from 50 to 1500, preferably from 80 to 800;
• the side chains of the random copolymer A1 have an average length ranging from 8 to 20 carbon atoms, preferably from 9 to 15 carbon atoms;
• the random copolymer A1 has a molar percentage of monomer M1 of formula (I) in said copolymer ranging from 1 to 30%, preferably from 5 to 25, more preferably from 9 to 21%;
• the random copolymer A1 has a mean degree of polymerization ranging from 100 to 2000, preferably from 150 to 1000;
• the lubricating oil is chosen from oils of group I, group II, group III, group IV, group V of the API classification and one of their mixtures;
• the composition further comprises a functional additive selected from the group consisting of detergents, anti-wear additives, extreme pressure additives, additional antioxidants, viscosity index improver polymers, pour point improvers, anti-foams, anti-corrosion additives, thickeners, dispersants, friction modifiers and mixtures thereof;
• the mass ratio in the composition between the random copolymer A1 and the compound A2 (ratio A1 / A2) ranges from 0.001 to 100, preferably from 0.05 to 20, even more preferably from 0.1 to 10, so still more preferably from 0.2 to 5;
• the sum of the masses of the random copolymer A1 and of the compound A2 in the composition is from 0.5 to 20% relative to the total weight of the lubricating composition and the lubricating oil mass ranges from 80% to 99.5% by relative to the total mass of the lubricating composition.

The invention also relates to the use of a composition as described above for lubricating a mechanical part.

• au moins un copolymère statistique A1 ;
• au moins un composé A2 comprenant au moins deux fonctions esters boroniques, le composé A2 pouvant s'associer et établir des liens chimiques covalents de type ester boronique avec le copolymère statistique A1 de manière thermoréversible; et
• au moins un additif fonctionnel choisi parmi le groupe formé par les détergents, les additifs anti-usures, les additifs extrêmes pression, les antioxydants, les polymères améliorant l'indice de viscosité, les améliorants de point d'écoulement, les anti-mousse, les épaississants, les dispersants, les modificateurs de frottements et leur mélange ;
  ∘ le copolymère statistique A1 résultant de la copolymérisation
  • ▪ d'au moins un premier monomère M1 de formule générale (I)
    
    dans laquelle :
    • R₁ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃ ;
    • x est un nombre entier allant de 2 à 18;
    • y est un nombre entier égal à 0 ou 1;
    • X₁ et X₂, identiques ou différents, sont choisis parmi le groupe formé par l'hydrogène, le tétrahydropyranyle, le méthyloxyméthyle, le ter-butyle, le benzyle, le triméthylsilyle et le t-butyle diméthylsilyle ;
      ou bien
    • X₁ et X₂ forment avec les atomes d'oxygène un pont de formule suivante
      
      dans laquelle:
      • les étoiles (*) symbolisent les liaisons aux atomes d'oxygène,
      • R'₂ et R"₂, identiques ou différents, sont choisis parmi le groupe formé par l'hydrogène et un alkyle en C₁-C₁₁, de préférence le méthyle;
      ou bien
    • X₁ et X₂ forment avec les atomes d'oxygène un ester boronique de formule suivante
      
      dans laquelle :
      • les étoiles (*) symbolisent les liaisons aux atomes d'oxygène,
      • R"'₂ est choisi parmi le groupe formé par un aryle en C₆-C₁₈, un aralkyle en C₇-C₁₈ et alkyle en C₂-C₁₈, de préférence un aryle en C₆-C₁₈;
  • ▪ avec au moins un second monomère M2 de formule générale (II-A) :
    
    dans laquelle :
    • R₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃,
    • R₃₁ est choisi parmi le groupe formé par un aryle en C₆-C₁₈, un aryle en C₆-C₁₈ substitué par un groupement R'₃, -C(O)-O-R'_3; -O-R'₃, -S-R'₃ et -C(O)-N(H)-R'₃ avec R'₃ un groupe alkyle en C₁-C₃₀.

The invention also relates to a parent composition resulting from the mixture of:

• at least one random copolymer A1;
• at least one compound A2 comprising at least two boronic ester functions, the compound A2 being able to associate and establish covalent chemical bonds of boronic ester type with the random copolymer A1 in a thermoreversible manner; and
• at least one functional additive selected from the group consisting of detergents, anti-wear additives, extreme pressure additives, antioxidants, viscosity index improvers, pour point improvers, defoamers, thickeners, dispersants, friction modifiers and mixtures thereof;
  ∘ the statistical copolymer A1 resulting from the copolymerization
  • At least one first monomer M1 of general formula (I)
    
    in which :
    • R ₁ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ ;
    • x is an integer from 2 to 18;
    • y is an integer equal to 0 or 1;
    • X ₁ and X ₂ , which are identical or different, are chosen from the group formed by hydrogen, tetrahydropyranyl, methyloxymethyl, tert-butyl, benzyl, trimethylsilyl and t-butyl dimethylsilyl;
      or
    • X ₁ and X ₂ form with the oxygen atoms a bridge of following formula
      
      in which:
      • the stars (*) symbolize the bonds to the oxygen atoms,
      • R ' ₂ and R " ₂ , which are identical or different, are chosen from the group formed by hydrogen and a C ₁ -C ₁₁ alkyl, preferably methyl;
      or
    • X ₁ and X ₂ form with the oxygen atoms a boronic ester of following formula
      
      in which :
      • the stars (*) symbolize the bonds to the oxygen atoms,
      • R "_'2 is selected from the group consisting of a C ₆ -C ₁₈ aralkyl, C ₇ -C ₁₈ alkyl and C ₂ -C _18, preferably C ₆ -C _18;
  • With at least one second monomer M2 of general formula (II-A):
    
    in which :
    • R ₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ ,
    • R ₃₁ is selected from the group consisting of a C ₆ -C ₁₈ aryl, C ₆ -C ₁₈ substituted by a group R _3, -C (O) -O-R _'3; -O-R ' ₃ , -S-R' ₃ and -C (O) -N (H) -R ' ₃ with R' ₃ a C ₁ -C ₃₀ alkyl group.

BRIEF DESCRIPTION OF THE FIGURES

• The figure 1 schematically represents a random copolymer (P1), a gradient copolymer (P2) and a block copolymer (P3), each ring represents a monomer unit. The difference in chemical structure between the monomers is symbolized by a different color (light gray / black).
• The figure 2 schematically represents a comb copolymer.
• The figure 3 schematically represents a solubility test of the composition according to the invention in tetrahydrofuran (THF).
• The figure 4 schematically represents the behavior of the composition of the invention as a function of temperature. A random copolymer (2) having diol functions (function A) can associate thermoreversibly with a random copolymer (1) having boronic ester functions (function B) via a transesterification reaction. The organic group of boronic ester functions (function B) which is exchanged during the transesterification reaction is a diol symbolized by a black crescent. A boronic ester chemical bond (3) is formed with the release of a diol compound.
• The figure 5 represents the variation, for different temperatures between 10 ° C and 110 ° C, of the viscosity (Pa.s, the y-axis) as a function of the shear rate (s ^-1 , the x-axis) d a 10% by weight solution of a polydiol random copolymer A1-1 and 0.77% by weight of a boronic diester compound A2-1 in the Group III base oil.
• The Figure 6A represents the evolution of the relative viscosity (without unit, the axis of ordinates) as a function of the temperature (° C, the abscissa axis) of the compositions A, B-1, C-1 and D-1.
• The Figure 6B represents the evolution of the relative viscosity (without unit, the ordinate axis) as a function of the temperature (° C, the abscissa axis) of the compositions A, B-2, C-2 and D-2.
• The Figure 6C represents the evolution of the relative viscosity (without unit, the ordinate axis) as a function of the temperature (° C, the abscissa axis) of the compositions A, B-3 and C-3.
• The Figure 6D represents the evolution of the relative viscosity (without unit, the ordinate axis) as a function of the temperature (° C, the abscissa axis) of the compositions A, B-4, C-4 and D-4.
• The figure 7 represents the variation, for different temperatures between 10 ° C and 110 ° C, of the viscosity (Pa.s, the ordinate axis) as a function of the shear rate (s ^-1 , the abscissa axis) of the composition E.
• The figure 8 represents the evolution of the relative viscosity (without unit, the ordinate axis) as a function of the temperature (° C, the abscissa axis) of the compositions A, B, C, D and E.
• The figure 9 schematically illustrates the boronic ester link exchange reactions between two polydiols random polymers (A1-1 and A1-2) and two boronic ester random polymers (A2-1 and A2-2) in the presence of diols.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

• au moins une huile lubrifiante,
• au moins un copolymère statistique A1, et
• au moins un composé A2 comprenant au moins deux fonctions esters boroniques;

le copolymère statistique A1 résultant de la copolymérisation d'au moins un premier monomère M1 portant des fonctions diols et d'au moins un second monomère M2 de structure chimique différente de celle du monomère M1.A first object of the invention is a composition resulting from the mixture of:

• at least one lubricating oil,
• at least one random copolymer A1, and
• at least one compound A2 comprising at least two boronic ester functions;

the random copolymer A1 resulting from the copolymerization of at least one first monomer M1 bearing diol functions and at least one second monomer M2 of chemical structure different from that of the monomer M1.

∘ Lubricating base oil

By "oil" means a fatty substance liquid at room temperature (25 ° C) and atmospheric pressure (760 mmm Hg evening 105 Pa).

By "lubricating oil" is meant an oil that reduces the friction between two moving parts to facilitate the operation of these parts. Lubricating oils can be of natural, mineral or synthetic origin.

Lubricating oils of natural origin may be oils of vegetable origin or animal, preferably vegetable oils such as rapeseed oil, sunflower oil, palm oil, coconut oil ...

Lubricating oils of mineral origin are of petroleum origin and are extracted from petroleum fractions from the atmospheric and vacuum distillation of crude oil. The distillation can be followed by refining operations such as solvent extraction, désalphatage, solvent dewaxing, hydrotreating, hydrocracking, hydroisomerisation, hydrofinition, etc. As an illustration, mention the paraffinic mineral base oils such as Bright Stock Solvent Oil (BSS), naphthenic mineral base oils, aromatic mineral oils, hydrorefined mineral bases with a viscosity number of about 100, mineral bases hydrocracked compounds whose viscosity index is between 120 and 130, the hydroisomerized mineral bases whose viscosity index is between 140 and 150.

• les huiles synthétiques à base d'hydrocarbures de synthèse telles que les polyalphaoléfines (PAO), les polyoléfines internes (PIO), les polybutènes et polyisobutènes (PIB), les dialkylbenènes, les polyphényles alkylés ;
• les huiles synthétiques à base d'esters telles que les esters de diacides, les esters de néopolyols ;
• les huiles synthétiques à base de polyglycols telles que les monoalkylèneglycols, les polyalkylèneglycols et les monoéthers de polyalkylèneglycols ;
• les huiles synthétiques à base d'ester-phosphates ;
• les huiles synthétiques à base de dérivés siliciés telles que les huiles silicones ou les polysiloxanes .

Lubricating oils of synthetic origin (or synthetic base) come as their name suggests chemical synthesis such as the addition of a product on itself or polymerization, or the addition of a product on another such as esterification, alkylation, fluorination, etc., of components derived from petrochemistry, carbochemistry, and mineral chemistry such as: olefins, aromatics, alcohols, acids, halogenated compounds, phosphorus compounds, silicones, etc. By way of illustration, mention may be made of:

• synthetic oils based on synthetic hydrocarbons such as polyalphaolefins (PAO), internal polyolefins (IOPs), polybutenes and polyisobutenes (PIB), dialkylbenenes, alkylated polyphenyls;
• synthetic oils based on esters such as diacid esters, neopolyol esters;
• synthetic polyglycol oils such as monoalkylene glycols, polyalkylene glycols and monoethers of polyalkylene glycols;
• synthetic oils based on ester-phosphates;
• synthetic oils based on silicon derivatives such as silicone oils or polysiloxanes.

Lubricating oils that can be used in the composition of the invention can be selected from any of the I to V oils specified in the API Guidelines (American Petroleum Institute's Basic Oil Interchangeability Guidelines). ) (or their equivalents according to the ATIEL classification (Technical Association of the European Lubricants Industry) as summarized below: Content of saturated compounds * Sulfur content ** Viscosity index (VI) ** Group I Mineral oils <90% > 0.03% 80 ≤ VI <120 Group II Hydrocracked oils ≥ 90% ≤ 0.03% 80 ≤ VI <120 Group III Hydrocracked or hydro-isomerized oils ≥ 90% ≤ 0.03% ≥ 120 Group IV (PAO) Polyalphaolefins Group V Esters and other bases not included in groups I to IV * measured according to ASTM D2007
** measured according to ASTM D2622, ASTM D4294, ASTM D4927 and ASTM D3120
** measured according to ASTM D2270

The compositions of the invention may comprise one or more lubricating oils. The lubricating oil or the mixture of lubricating oils represents at least 50% by weight relative to the total weight of the composition.

Preferably, the lubricating oil or the lubricating oil mixture represents at least 70% by weight relative to the total weight of the composition.

In one embodiment of the invention, the lubricating oil is selected from the group consisting of oils of group I, group II, group III, group IV, group V of the API classification and one of their mixture. Preferably, the lubricating oil is chosen from the group consisting of oils of group III, group IV, group V of the API classification and their mixture. Preferably, the lubricating oil is a Group III API oil.

The lubricating oil has a kinematic viscosity at 100 ° C measured according to ASTM D445 ranging from 2 to 150 cSt, preferably from 5 to 15 cSt.

Lubricating oils can range from SAE grade 15 to SAE grade 250, and most preferably SAE grade 20W to grade SAE 50 (SAE stands for Society of Automotive Engineers).

∘ Polydiol random copolymers (statistical copolymer A1)

The composition of the invention comprises at least one polydiol random copolymer resulting from the copolymerization of at least one first monomer M1 bearing diol functions and at least one second monomer M2, with a chemical structure different from that of the monomer M1.

By "copolymer" is meant a linear or branched oligomer or macromolecule having a sequence consisting of several repeating units (or monomeric unit) of which at least two units have a different chemical structure.

By "monomeric unit" or "monomer" is meant a molecule capable of being converted into an oligomer or a macromolecule by combination with itself or with other molecules of the same type. A monomer refers to the smallest constituent unit whose repetition leads to an oligomer or a macromolecule.

The term "random copolymer" is understood to mean an oligomer or a macromolecule in which the sequential distribution of the monomeric units obeys known statistical laws. For example, a copolymer is said to be random when it consists of monomeric units whose distribution is a Markovian distribution. A schematic statistical polymer (P1) is illustrated in figure 1 . The distribution in the polymer chain of the monomer units depends on the reactivity of the polymerizable functions of the monomers and the relative concentration of the monomers. The polydiol random copolymers of the invention are distinguished from block copolymers and gradient polymers. By "block" is meant a part of a copolymer comprising several identical or different monomer units and which have at least one particular constitution or configuration to distinguish it from its adjacent parts. A schematic block copolymer (P3) is illustrated in figure 1 . A gradient copolymer refers to a copolymer of at least two monomeric units of different structures whose monomer composition gradually changes along the polymer chain, thus progressively passing from one end of the rich polymer chain into a pattern. monomer, at the other end rich in the other comonomer. A schematic gradient polymer (P2) is illustrated in figure 1 .

By "copolymerization" is meant a process which makes it possible to convert a mixture of at least two monomeric units of different chemical structures into an oligomer or a copolymer.

In the rest of the present application, "B" represents a boron atom.

The term "C _i -C _j" means a saturated hydrocarbon chain, linear or branched, comprising from i to j carbon atoms. For example, for "C ₁ -C ₁₀ alkyl" is meant a saturated hydrocarbon chain, linear or branched, comprising from 1 to 10 carbon atoms.

By "C ₆ -C ₁₈ aryl" is meant a functional group derived from an aromatic hydrocarbon compound having from 6 to 18 carbon atoms. This functional group can be monocyclic or polycyclic. By way of illustration, a C ₆ -C ₁₈ aryl may be phenyl, naphthalene, anthracene, phenanthrene and tetracene.

By "C ₂ -C ₁₀ alkenyl" is meant a linear or branched hydrocarbon chain containing at least one unsaturation, preferably a double bond, and comprising from 2 to 10 carbon atoms.

By "C ₇ -C ₁₈ aralkyl" is meant an aromatic hydrocarbon compound, preferably monocyclic, substituted by at least one linear or branched alkyl chain and the total number of carbon atoms of the aromatic ring and its substituents ranging from 7 to 18 carbon atoms. By way of illustration, a C ₇ -C ₁₈ aralkyl may be chosen from the group formed by benzyl, tolyl and xylyl.

By "C ₆ -C ₁₈ aryl group substituted by a group R ' ₃ " is meant an aromatic hydrocarbon compound preferably monocyclic, comprising from 6 to 18 carbon atoms, at least one carbon atom of the aromatic ring is substituted by a group R ' ₃ .

By "Hal" or "halogen" is meant a halogen selected from the group consisting of chlorine, bromine, fluorine and iodine.

• Monomer M1

dans laquelle :

• R₁ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃, de préférence -H et -CH₃;
• x est un nombre entier allant de 2 à 18; de préférence de 3 à 8 ; de manière plus préférée x est égal à 4 ;
• y est un nombre entier égal à 0 ou 1; de préférence y est égal à 0 ;
• X₁ et X₂, identiques ou différents, sont choisis parmi le groupe formé par l'hydrogène, le tétrahydropyranyle, le méthyloxyméthyle, le ter-butyle, le benzyle, le triméthylsilyle et le t-butyle diméthylsilyle ;
  ou bien
• X₁ et X₂ forment avec les atomes d'oxygène un pont de formule suivante :
  
  dans laquelle :
  • les étoiles (*) symbolisent les liaisons aux atomes d'oxygène,
  • R'₂ et R"₂, identiques ou différents, sont choisis parmi le groupe formé par l'hydrogène et un groupe alkyle en C₁-C₁₁ ;
  ou bien
• X₁ et X₂ forment avec les atomes d'oxygène un ester boronique de formule suivante :
  
  dans laquelle :
  • les étoiles (*) symbolisent les liaisons aux atomes d'oxygène,
  • R"'₂ est choisi parmi le groupe formé par un aryle en C₆-C₁₈, un aralkyle en C₇-C₁₈ et un alkyle en C₂-C₁₈, de préférence un aryle en C₆-C₁₈, de manière plus préférée le phényle.

The first monomer M1 of the polydiol random copolymer (A1) of the invention has the general formula (I):

in which :

• R ₁ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ , preferably -H and -CH ₃ ;
• x is an integer from 2 to 18; preferably from 3 to 8; more preferably x is 4;
• y is an integer equal to 0 or 1; preferably y is 0;
• X ₁ and X ₂ , which are identical or different, are chosen from the group formed by hydrogen, tetrahydropyranyl, methyloxymethyl, tert-butyl, benzyl, trimethylsilyl and t-butyl dimethylsilyl;
  or
• X ₁ and X ₂ form with the oxygen atoms a bridge of the following formula:
  
  in which :
  • the stars (*) symbolize the bonds to the oxygen atoms,
  • R ' ₂ and R " ₂ , which may be identical or different, are chosen from the group formed by hydrogen and a C ₁ -C ₁₁ alkyl group;
  or
• X ₁ and X ₂ form with the oxygen atoms a boronic ester of the following formula:
  
  in which :
  • the stars (*) symbolize the bonds to the oxygen atoms,
  • R "' ₂ is selected from the group consisting of a C ₆ -C ₁₈ aryl, a C ₇ -C ₁₈ aralkyl and a C ₂ -C ₁₈ alkyl, preferably a C ₆ -C ₁₈ aryl, more preferably phenyl.

Preferably, when R ' ₂ and R " ₂ is a C ₁ -C ₁₁ alkyl group, the hydrocarbon chain is a linear chain, preferably the C ₁ -C ₁₁ alkyl group is chosen from the group formed by methyl ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decycling and n-undecyl. More preferably, the C ₁ -C ₁₁ alkyl group is methyl.

Preferably, when R "' ₂ is a C ₂ -C ₁₈ alkyl group, the hydrocarbon chain is a linear chain.

dans laquelle :

• R₁ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃, de préférence -H et -CH₃;
• x est un nombre entier allant de 2 à 18; de préférence de 3 à 8 ; de manière plus préférée x est égal à 4 ;
• y est un nombre entier égal à 0 ou 1; de préférence y est égal à 0.

Among the monomers of formula (I), the monomers corresponding to formula (IA) are among the preferred ones:

in which :

• R ₁ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ , preferably -H and -CH ₃ ;
• x is an integer from 2 to 18; preferably from 3 to 8; more preferably x is 4;
• y is an integer equal to 0 or 1; preferably y is 0.

dans laquelle :

• R₁ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃, de préférence -H et -CH₃;
• x est un nombre entier allant de 2 à 18; de préférence de 3 à 8 ; de manière plus préférée x est égal à 4 ;
• y est un nombre entier égal à 0 ou 1; de préférence y est égal à 0 ;
• Y₁ et Y₂, identiques ou différents, sont choisis parmi le groupe formé par le tétrahydropyranyle, le méthyloxyméthyle, le ter-butyle, le benzyle, le triméthylsilyle et le t-butyle diméthylsilyle ;
  ou bien
• Y₁ et Y₂ forment avec les atomes d'oxygène un pont de formule suivante :
  
  dans laquelle :
  • les étoiles (*) symbolisent les liaisons aux atomes d'oxygène,
  • R'₂ et R"₂, identiques ou différents, sont choisis parmi le groupe formé par l'hydrogène et un groupe alkyle en C₁-C₁₁ ;
  ou bien
• Y₁ et Y₂ forment avec les atomes d'oxygène un ester boronique de formule suivante :
  
  dans laquelle :
  • les étoiles (*) symbolisent les liaisons aux atomes d'oxygène,
  • R"'₂ est choisi parmi le groupe formé par un aryle en C₆-C₁₈, un aralkyle en C₇-C₁₈ et un alkyle en C₂-C₁₈, de préférence un aryle en C₆-C₁₈, de manière plus préférée le phényle.

Among the monomers of formula (I), the monomers corresponding to formula (IB) are among the preferred ones:

in which :

• R ₁ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ , preferably -H and -CH ₃ ;
• x is an integer from 2 to 18; preferably from 3 to 8; more preferably x is 4;
• y is an integer equal to 0 or 1; preferably y is 0;
• Y ₁ and Y ₂ , which are identical or different, are chosen from the group formed by tetrahydropyranyl, methyloxymethyl, tert-butyl, benzyl, trimethylsilyl and t-butyl dimethylsilyl;
  or
• Y ₁ and Y ₂ form with the oxygen atoms a bridge of the following formula:
  
  in which :
  • the stars (*) symbolize the bonds to the oxygen atoms,
  • R ' ₂ and R " ₂ , which may be identical or different, are chosen from the group formed by hydrogen and a C ₁ -C ₁₁ alkyl group;
  or
• Y ₁ and Y ₂ form with the oxygen atoms a boronic ester of the following formula:
  
  in which :
  • the stars (*) symbolize the bonds to the oxygen atoms,
  • R "' ₂ is selected from the group consisting of a C ₆ -C ₁₈ aryl, a C ₇ -C ₁₈ aralkyl and a C ₂ -C ₁₈ alkyl, preferably a C ₆ -C ₁₈ aryl, more preferably phenyl.

Preferably, when R ' ₂ and R " ₂ is a C ₁ -C ₁₁ alkyl group, the chain hydrocarbon is a linear chain. Preferably, the C ₁ -C ₁₁ alkyl group is chosen from the group formed by methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decycling and n-undecyl. More preferably, the C ₁ -C ₁₁ alkyl group is methyl.

Preferably, when R "' ₂ is a C ₂ -C ₁₈ alkyl group, the hydrocarbon chain is a linear chain.

• Obtaining the monomer M1

avec R₁, Y₁, Y₂, x et y tels que définis dans la formule générale (IB) décrite ci-dessus.The monomer M1 of general formula (IA) is obtained by deprotection of the alcohol functional groups of the monomer of general formula (IB) according to reaction scheme 1 below:

with R ₁ , Y ₁ , Y ₂ , x and y as defined in the general formula (IB) described above.

The deprotection reaction of the diol functions of the monomer of general formula (IB) is well known to those skilled in the art. It knows how to adapt the reaction conditions of deprotection according to the nature of the protective groups Y ₁ and Y ₂ .

dans lequel

• Y₃ est choisi parmi le groupe formé par un atome d'halogène, de préférence le chlore, -OH et O-C(O)-R'₁ avec R'₁ choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃, de préférence -H et -CH_3;
• R₁, Y₁, Y₂, x et y ont la même signification que celle donnée dans formule générale (I-B).

The monomer M1 of general formula (IB) may be obtained by a reaction of a compound of general formula (Ic) with an alcohol compound of general formula (Ib) according to reaction scheme 2 below:

in which

• Y ₃ is chosen from the group formed by a halogen atom, preferably chlorine, -OH and OC (O) -R ' ₁ with R' ₁ chosen from the group formed by -H, -CH ₃ and -CH ₂ -CH _3, preferably -H and -CH _3;
• R ₁ , Y ₁ , Y ₂ , x and y have the same meaning as that given in general formula (IB).

These coupling reactions are well known to those skilled in the art.

The compound of general formula (I-c) is commercially available from suppliers: Sigma-Aldrich® and Alfa Aesar®.

avec x, y, Y₁ et Y₂ tels que définis dans la formule générale (I-B).The alcohol compound of general formula (Ib) is obtained from the corresponding polyol of formula (Ia) by protecting the diol functions according to the following reaction scheme 3:

with x, y, Y ₁ and Y ₂ as defined in the general formula (IB).

The protective reaction of the diol functions of the compound of general formula (Ia) is well known to those skilled in the art. It knows how to adapt the reaction protection conditions according to the nature of the protective groups Y ₁ and Y ₂ used.

The polyol of general formula (Ia) is commercially available from suppliers: Sigma-Aldrich® and Alfa Aesar®.

• Monomer M2

dans laquelle :

• R₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃, de préférence -H ou -CH₃;
• R₃ est choisi parmi le groupe formé par un atome d'hydrogène, un groupement alkyle en C₁-C₁₀, un groupement alcényle en C₂-C₁₀, un groupement aryle en C₆-C₁₈, un aryle en C₆-C₁₈ substitué par un groupement R'₃, -C(O)-O-R'_3; -O-R'₃, -S-R'₃ et -C(O)-N(H)-R'₃ avec R'₃ un groupe alkyle en C₁-C₃₀.

The second monomer of the random copolymer of the invention has the general formula (II):

in which :

• R ₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ , preferably -H or -CH ₃ ;
• R ₃ is selected from the group consisting of a hydrogen atom, a C ₁ -C ₁₀ alkyl group, a C ₂ -C ₁₀ alkenyl group, a C ₆ -C ₁₈ aryl group, a C ₆ aryl group; -C ₁₈ substituted with a group R ' ₃ , -C (O) -O-R'_3; -O-R ' ₃ , -S-R' ₃ and -C (O) -N (H) -R ' ₃ with R' ₃ a C ₁ -C ₃₀ alkyl group.

Preferably, R ' ₃ is a C ₁ -C ₃₀ alkyl group whose hydrocarbon chain is linear.

dans laquelle :

• R₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃, de préférence -H ou -CH₃ ;
• R₃₁ est choisi parmi le groupe formé par un groupement aryle en C₆-C₁₈, un aryle en C₆-C₁₈ substitué par un groupement R'₃, -C(O)-O-R'_3; -O-R'₃, -S-R'₃ et -C(O)-N(H)-R'₃ avec R'₃ un groupe alkyle en C₁-C₃₀.

Among the monomers of formula (II), the monomers corresponding to formula (II-A) are among the preferred

in which :

• R ₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ , preferably -H or -CH ₃ ;
• R ₃₁ is selected from the group consisting of aryl, C ₆ -C ₁₈ aryl, C ₆ -C ₁₈ substituted by a group R _3, -C (O) -O-R _'3; -O-R ' ₃ , -S-R' ₃ and -C (O) -N (H) -R ' ₃ with R' ₃ a C ₁ -C ₃₀ alkyl group.

Preferably, R ' ₃ is a C ₁ -C ₃₀ alkyl group whose hydrocarbon chain is linear.

dans laquelle :

• R₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃, de préférence -H et -CH₃;
• R"₃₁ est un groupe alkyle en C₁-C₁₄.

Among the monomers of formula (II-A), the monomers corresponding to formula (II-A1) are among the preferred ones:

in which :

• R ₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ , preferably -H and -CH ₃ ;
• R " ₃₁ is a C ₁ -C ₁₄ alkyl group.

By "C ₁ -C ₁₄ alkyl group" is meant a saturated hydrocarbon chain, linear or branched comprising from 1 to 14 carbon atoms. Preferably, the hydrocarbon chain is linear. Preferably, the hydrocarbon chain comprises from 4 to 12 carbon atoms.

dans laquelle :

• R₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH_3, de préférence -H et -CH₃;
• R"'₃₁ est un groupe alkyle en C₁₅-C₃₀.

Among the monomers of formula (II-A), the monomers corresponding to formula (II-A2) are also among the preferred ones:

in which :

• R ₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH _3, preferably -H and -CH ₃ ;
• R "_'31 is a C ₁₅ -C ₃₀ alkyl group.

By "C ₁₅ -C ₃₀ alkyl group" is meant a linear or branched saturated hydrocarbon chain comprising from 15 to 30 carbon atoms. Preferably, the hydrocarbon chain is linear. Preferably, the hydrocarbon chain comprises from 16 to 24 carbon atoms.

dans laquelle :

• R₂₂ est choisi parmi le groupe formé par H et CH₃ ;
• R₃₂ est choisi parmi le groupe formé par un atome d'hydrogène, un groupement alkyle en C₁-C₁₀ et un groupement alcényle en C₂-C₁₀.

Among the monomers of formula (II); the monomers corresponding to formula (II-B) are among the preferred ones:

in which :

• R ₂₂ is selected from the group consisting of H and CH ₃ ;
• R ₃₂ is selected from the group consisting of a hydrogen atom, a C ₁ -C ₁₀ alkyl group and a C ₂ -C ₁₀ alkenyl group.

• Obtaining M2 monomer

The monomers of formula (II), (II-A), especially (II-A1) and (II-A2), (II-B) are well known to those skilled in the art. They are marketed by Sigma-Aldrich® and TCI®.

• Preferred polydiol copolymers

• un premier monomère M1 de formule générale (I) tel que décrit précédemment ;
• un second monomère M2 de formule (II) tel que décrit précédemment, dans laquelle R₂ est -H et R₃ est un groupement aryle en C₆-C₁₈; de préférence R₃ est le phényle.

In one embodiment, a preferred random copolymer results from the copolymerization of at least:

• a first monomer M1 of general formula (I) as described above;
• a second monomer M2 of formula (II) as described above, in which R ₂ is -H and R ₃ is a C ₆ -C ₁₈ aryl group; preferably, R ₃ is phenyl.

• un premier monomère M1 de formule générale (I) tel que décrit précédemment ;
• un second monomère M2 de formule (II-A1) tel que décrit précédemment ; et
• un troisième monomère M2 de formule (II-A2) tel que décrit précédemment.

In another embodiment, a preferred random copolymer results from the copolymerization of at least:

• a first monomer M1 of general formula (I) as described above;
• a second monomer M2 of formula (II-A1) as described above; and
• a third monomer M2 of formula (II-A2) as described above.

• un premier monomère M1 de formule générale (I) tel que décrit précédemment ;
• un second monomère M2 de formule (II-A1) dans laquelle R₂ est CH₃ et R"₃₁ est un groupe alkyle en C₄-C₁₂, de préférence un alkyle linéaire en C₄-C₁₂
• un troisième monomère M2 de formule (II-A2) dans laquelle R₂ est CH₃ et R"'₃₁ est un groupe alkyle en C₁₆-C₂₄, de préférence un alkyle linéaire en C₁₆-C₂₄.

According to this other embodiment, a preferred random copolymer results from the copolymerization of at least:

• a first monomer M1 of general formula (I) as described above;
• a second monomer M2 of formula (II-A1) in which R ₂ is CH ₃ and R " ₃₁ is a C ₄ -C ₁₂ alkyl group, preferably a linear C ₄ -C ₁₂ alkyl
• a third monomer M2 of formula (II-A2) in which R ₂ is CH ₃ and R "_'31 is a C ₁₆ -C ₂₄ alkyl group, preferably a linear C ₁₆ -C ₂₄ alkyl.

• un premier monomère M1 de formule générale (I) tel que décrit précédemment ;
• un second monomère M2 choisi dans le groupe formé par le méthacrylate de n-octyle, le méthacrylate de n-décyle et le méthacrylate de n-dodécyle ;
• un troisième monomère M2 choisi dans le groupe formé par le méthacrylate de palmityle, le méthacrylate de stéaryle, le méthacrylate d'arachidyle et le méthacrylate de béhényle.

According to this embodiment, a preferred random copolymer results from the copolymerization of at least:

• a first monomer M1 of general formula (I) as described above;
• a second monomer M2 selected from the group consisting of n-octyl methacrylate, n-decyl methacrylate and n-dodecyl methacrylate;
• a third monomer M2 selected from the group consisting of palmityl methacrylate, stearyl methacrylate, arachidyl methacrylate and behenyl methacrylate.

• un premier monomère M1 de formule générale (I) tel que défini précédemment ;
• un second monomère M2 de formule (II-B) tel que défini précédemment, dans lequel R₂₂ et R₃₂ sont un atome d'hydrogène ;
• un troisième monomère M2 de formule (II-B) tel que défini précédemment dans laquelle R₂₂ est un atome d'hydrogène, R₃₂ est un groupement alkyle en C₁-C₁₀, de préférence R₃₂ un groupement alkyle linéaire en C₁-C₁₀, depréférence R₃₂ est choisi parmi le groupe constitué par CH₃, CH₂-CH₃, CH₂-CH₂-CH₃, CH₂-(CH₂)₂-CH₃ et CH₂-(CH₂)₃CH₃.

In another embodiment, a preferred random copolymer results from the copolymerization of at least:

• a first monomer M1 of general formula (I) as defined above;
• a second monomer M2 of formula (II-B) as defined above, in which R ₂₂ and R ₃₂ are a hydrogen atom;
• a third monomer M2 of formula (II-B) as defined above in which R ₂₂ is a hydrogen atom, R ₃₂ is a C ₁ -C ₁₀ alkyl group, preferably R ₃₂ a linear C ₁ alkyl group -C ₁₀ , preferably R ₃₂ is selected from the group consisting of CH ₃ , CH ₂ -CH ₃ , CH ₂ -CH ₂ -CH ₃ , CH ₂ - (CH ₂ ) ₂ -CH ₃ and CH ₂ - (CH ₂ ) ₃ CH ₃ .

• un premier monomère M1 de formule générale (I) tel que défini précédemment ;
• un second monomère M2 de formule (II-B) qui est l'éthylène ;
• un troisième monomère M2 de formule (II-B) qui est le propylène.

According to this embodiment, a preferred random copolymer results from the copolymerization of at least:

• a first monomer M1 of general formula (I) as defined above;
• a second monomer M2 of formula (II-B) which is ethylene;
• a third monomer M2 of formula (II-B) which is propylene.

• un premier monomère M1 de formule générale (I) tel que définit précédemment ;
• un second monomère M2 de formule générale (II-B) tel que défini précédemment, dans lequel R₂₂ est un atome d'hydrogène et R₃₂ est choisi dans le groupe formé par un hydrogène et un groupement alkyle en C₁-C₁₀;
• un troisième monomère M2 de formule générale (II-A1) tel que défini précédemment.

In another embodiment, a preferred random copolymer results from a copolymerization step of at least:

• a first monomer M1 of general formula (I) as defined above;
• a second monomer M2 of general formula (II-B) as defined above, wherein R ₂₂ is a hydrogen atom and R ₃₂ is selected from the group consisting of hydrogen and a C ₁ -C ₁₀ alkyl group;
• a third monomer M2 of general formula (II-A1) as defined above.

• un premier monomère M1 de formule générale (I) tel que décrit précédemment ;
• un second monomère M2 de formule (II) tel que décrit précédemment, dans laquelle R₂ est H et R₃ est un groupement aryle en C₆-C₁₈; de préférence R₃ est le phényle ; et
• un troisième monomère M2 de formule (II-B) tel que décrit précédemment, dans laquelle R₂₂ est choisi parmi le groupe formé par H ou CH₃, R₃₂ est un groupement alcényle en C₂-C₁₀, de préférence R₃₂ est -C(H)=CH2 ;

et d'une étape d'hydrogénation.
L'hydrogénation peut être accomplie par toute technique bien connue de l'homme du métier.In another embodiment, a preferred random copolymer results from a copolymerization step of at least:

• a first monomer M1 of general formula (I) as described above;
• a second monomer M2 of formula (II) as described above, in which R ₂ is H and R ₃ is a C ₆ -C ₁₈ aryl group; preferably, R ₃ is phenyl; and
• a third monomer M2 of formula (II-B) as described above, in which R ₂₂ is chosen from the group formed by H or CH ₃ , R ₃₂ is a C ₂ -C ₁₀ alkenyl group, preferably R ₃₂ is -C (H) = CH2;

and a hydrogenation step.
Hydrogenation can be accomplished by any technique well known to those skilled in the art.

Process for obtaining polydiol copolymers

Those skilled in the art are able to synthesize the polydiols random copolymers A1 of the invention using his general knowledge.

The copolymerization can be initiated in bulk or in solution in an organic solvent with compounds generating free radicals. For example, the copolymers of the invention, in particular those resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) ) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), are obtained by the known methods of radical copolymerization, controlled in particular such as the method called controlled radical polymerization controlled by reversible addition-fragmentation chain transfer (in English: Reversible Addition-Fragmentation Chain Transfer (RAFT)) and the so-called atom controlled transfer radical polymerization method (in English Atom Transfer Radical Polymerization (ARTP)). Conventional radical polymerization and telomerization can also be employed to prepare the copolymers of the invention ( Moad, G .; Solomon, DH, The Chemistry of Radical Polymerization. 2nd ed .; Elsevier Ltd: 2006; p 639 ; Matyaszewski, K .; Davis, TP Handbook of Radical Polymerization; Wiley-Interscience: Hoboken, 2002; p 936 ).

1. i) un premier monomère M1 de formule générale (I) :
   
   dans laquelle :
   • R₁ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃ ;
   • x est un nombre entier allant de 2 à 18;
   • y est un nombre entier égal à 0 ou 1;
   • X₁ et X₂, identiques ou différents, sont choisis parmi le groupe formé par l'hydrogène, le tétrahydropyranyle, le méthyloxyméthyle, le ter-butyle, le benzyle, le triméthylsilyle et le t-butyle diméthylsilyle ;
     ou bien
   • X₁ et X₂ forment avec les atomes d'oxygène un pont de formule suivante
     
     dans laquelle:
     • les étoiles (*) symbolisent les liaisons aux atomes d'oxygène ;
     • R'₂ et R"₂, identiques ou différents, sont choisis parmi le groupe formé l'hydrogène et un alkyle en C₁-C₁₁, de préférence le méthyle;
     ou bien
   • X₁ et X₂ forment avec les atomes d'oxygène un ester boronique de formule suivante
     
     dans laquelle :
     • les étoiles (*) symbolisent les liaisons aux atomes d'oxygène ;
     • R"'₂ est choisi parmi le groupe formé par un aryle en C₆-C₁₈, un aralkyle en C₇-C₁₈ et alkyle en C₂-C₁₈, de préférence un aryle en C₆-C₁₈;
2. ii) au moins un second monomère M2 de formule générale (II-A) :
   
   dans laquelle :
   • R₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃,
   • R₃ est choisi parmi le groupe formé par un aryle en C₆-C₁₈, un aryle en C₆-C₁₈ substitué par un groupement R'₃, -C(O)-O-R'_3; -O-R'₃, -S-R'₃ et -C(O)-N(H)-R'₃ avec R'₃ un groupe alkyle en C₁-C₃₀;
3. iii) au moins une source de radicaux libres.

A method for preparing a random copolymer comprises at least one polymerization step (a) in which at least one:

1. i) a first monomer M1 of general formula (I):
   
   in which :
   • R ₁ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ ;
   • x is an integer from 2 to 18;
   • y is an integer equal to 0 or 1;
   • X ₁ and X ₂ , which are identical or different, are chosen from the group formed by hydrogen, tetrahydropyranyl, methyloxymethyl, tert-butyl, benzyl, trimethylsilyl and t-butyl dimethylsilyl;
     or
   • X ₁ and X ₂ form with the oxygen atoms a bridge of following formula
     
     in which:
     • the stars (*) symbolize the bonds to the oxygen atoms;
     • R ' ₂ and R " ₂ , which are identical or different, are chosen from the group formed by hydrogen and a C ₁ -C ₁₁ alkyl, preferably methyl;
     or
   • X ₁ and X ₂ form with the oxygen atoms a boronic ester of following formula
     
     in which :
     • the stars (*) symbolize the bonds to the oxygen atoms;
     • R "_'2 is selected from the group consisting of a C ₆ -C ₁₈ aralkyl, C ₇ -C ₁₈ alkyl and C ₂ -C _18, preferably C ₆ -C _18;
2. ii) at least one second monomer M2 of general formula (II-A):
   
   in which :
   • R ₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ ,
   • R ₃ is selected from the group consisting of a C ₆ -C ₁₈ aryl, C ₆ -C ₁₈ substituted by a group R _3, -C (O) -O-R _'3; -O-R ' ₃ , -S-R' ₃ and -C (O) -N (H) -R ' ₃ with R' ₃ a C ₁ -C ₃₀ alkyl group;
3. iii) at least one source of free radicals.

In one embodiment, the method may further include iv) at least one chain transfer agent.

By "a source of free radicals" is meant a chemical compound or for generating a chemical species having one or more unpaired electrons on its outer layer. Those skilled in the art can use any source of free radicals known per se as suitable for polymerization processes, especially controlled radical polymerization. Among the sources of free radicals, benzoyl peroxide, tert-butyl peroxide, diazo compounds such as azobisisobutyronitrile, peroxygen compounds, such as persulfates or the like, are preferred by way of illustration. oxygenated water, redox systems such as oxidation of Fe ²⁺ , persulfate / sodium-metabisulphite mixtures, or ascorbic acid / hydrogen peroxide, or photochemically cleavable compounds or by ionizing radiation, for example ultraviolet rays or by beta or gamma radiation.

"Chain transfer agent" means a compound the purpose of which is to ensure homogeneous growth of macromolecular chains by reversible transfer reactions between growing species, ie polymer chains terminated by a carbon radical, and dormant species, ie polymer chains terminated by a transfer agent. This reversible transfer process makes it possible to control the molecular masses of copolymers thus prepared. Preferably in the process of the invention, the chain transfer agent comprises a thiocarbonylthio group -SC (= S) -. As an illustration of chain transfer agent, mention may be made of dithioesters, trithiocarbonates, xanthates and dithiocarbamates. A preferred transfer agent is cumyl dithiobenzoate or 2-cyano-2-propyl benzodithioate.

By "chain transfer agent" is also meant a compound whose purpose is to limit the growth of the macromolecular chains being formed by addition of monomer molecules and to start new chains, which makes it possible to limit the molecular masses final, even to control them. Such a type of transfer agent is used in telomerization. A preferred transfer agent is cysteamine.

• au moins une étape de polymérisation (a) telle que définie ci-dessus, dans laquelle les monomères M1 et M2 sont choisis avec X₁ et X₂ différents de l'hydrogène, et en outre
• au moins une étape de déprotection (b) des fonctions diol du copolymère obtenu à l'issue de l'étape (a), de façon à obtenir un copolymère dans lequel X₁ et X₂ sont identiques et sont un atome d'hydrogène.

The process for preparing a polydiol random copolymer comprises:

• at least one polymerization step (a) as defined above, in which the monomers M1 and M2 are chosen with X ₁ and X ₂ different from hydrogen, and furthermore
• at least one deprotection step (b) of the diol functions of the copolymer obtained at the end of step (a), so as to obtain a copolymer in which X ₁ and X ₂ are identical and are a hydrogen atom.

In one embodiment, the polymerization step (a) comprises contacting at least one monomer M1 with at least two monomers M2 having different R ₃₁ groups.

dans laquelle :

• R₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃, de préférence -H et -CH₃;
• R"₃₁ est un groupe alkyle en C₁-C₁₄;

et l'autre monomère M2 a pour formule générale (II-A2)

dans laquelle :

• R₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃, de préférence -H et -CH₃;
• R"'₃₁ est un groupe alkyle en C₁₅-C₃₀.

In this embodiment, one of the monomers M2 has the general formula (II-A1)

in which :

• R ₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ , preferably -H and -CH ₃ ;
• R " ₃₁ is a C ₁ -C ₁₄ alkyl group;

and the other monomer M2 has the general formula (II-A2)

in which :

• R ₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ , preferably -H and -CH ₃ ;
• R "_'31 is a C ₁₅ -C ₃₀ alkyl group.

The preferences and definitions described for the general formulas (I), (I-A), (I-B), (II-A), (II-A1) and (II-A2) also apply to the processes described above.

Properties of Polydiols Copolymers A1

The polydiol random copolymers A1 of the invention are comb copolymers.

"Comb copolymers" means a copolymer having a main chain (also called backbone) and side chains. The side chains are hanging on both sides of the main chain. The length of each side chain is less than the length of the main chain. The figure 2 schematically represents a comb polymer.

The copolymers of the invention in particular those resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one a monomer of formula (II-A1) and at least one monomer of formula (II-A2), have a skeleton of polymerizable functions, in particular a skeleton of methacrylate functions, and a mixture of hydrocarbon side chains substituted or not by diol functions .

As the monomers of formula (I) and (II-A) have polymerizable functions of identical or substantially identical reactivity, a copolymer is obtained in which the monomers having diol functions are statistically distributed along the backbone of the copolymer relative to the monomers of which the alkyl chains are unsubstituted by diol functions.

The polydiol random copolymers of the invention, especially those resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), have the advantage of being sensitive to external stimuli, such as temperature, pressure, shear rate ; this sensitivity translates into a change of properties. In response to a stimulus, the conformation in space of the copolymer chains is modified and the diol functions are rendered more or less accessible to the association reactions, which can generate crosslinking, as well as to the exchange reactions. These processes of association and exchange are reversible. The The copolymer of the invention A1 is a thermosensitive copolymer, that is to say that it is sensitive to changes in temperature.

Advantageously, the side chains of the polydiol random copolymer, in particular that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I ) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), have an average length ranging from 8 to 20 carbon atoms, preferably from 9 to 15 carbon atoms. By "average side chain length" is meant the average side chain length of each monomer constituting the copolymer. Those skilled in the art can obtain this average length by appropriately selecting the types and ratio of monomers constituting the polydiol random copolymer. The choice of this average chain length makes it possible to obtain a polymer that is soluble in a hydrophobic medium, whatever the temperature at which the copolymer is dissolved. The copolymer is therefore miscible in a hydrophobic medium. By "hydrophobic medium" is meant a medium that has no or a very low affinity for water, that is to say it is not miscible in water or in an aqueous medium.

Advantageously, the polydiol random copolymer of the invention, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula ( I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), has a molar percentage of monomer M1 of formula (I) in said copolymer ranging from 1 to 30%, preferably ranging from 5 to 25%, more preferably from 9 to 21%.

In a preferred embodiment of the invention, the copolymer of the invention has a molar percentage of monomer M1 of formula (I) in said copolymer ranging from 1 to 30%, preferably 5 to 25%, more preferably ranging from 9 to 21%, a molar percentage of monomer M2 of formula (II-A1) in said copolymer ranging from 8 to 92% and a molar percentage of monomer M2 of formula (II-A2) in said copolymer ranging from 0, 1 to 62%. The molar percentage of monomers in the copolymer results directly from the adjustment of the amounts of monomers used for the synthesis of the copolymer.

In a preferred embodiment, the copolymer A1 has a molar percentage of monomer M1 of formula (I) in said copolymer ranging from 1 to 30%, a molar percentage of monomer M2 of formula (II-A) in said copolymer ranging from 8 to 62% and a molar percentage of M2 monomer of formula (II-B) in said copolymer ranging from 8 to 91%. The molar percentage of monomers in the copolymer results directly from the adjustment of the amounts of monomers used for the synthesis of the copolymer.

Advantageously, the polydiol random copolymer of the invention, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula ( I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), at a degree of number-average polymerization ranging from 100 to 2000, preferably from 150 to 1000. In known manner, the degree of polymerization is controlled using a controlled radical polymerization technique, a telomerization technique or by adjusting the amount of source of free radicals when the copolymers of the invention are prepared by conventional radical polymerization.

Advantageously, the polydiol random copolymer of the invention, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula ( I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), has a polydispersity index (Ip) ranging from 1.05 to 3.75; preferably from 1.10 to 3.45. The polydispersity index is obtained by measurement of size exclusion chromatography using a polystyrene calibration.

Advantageously, the polydiol random copolymer of the invention, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula ( I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), has a number-average molar mass ranging from 10,000 to 400,000 g / mol, preferably 25,000 at 150,000 g / mol, the number-average molar mass being obtained by steric exclusion chromatography using a polystyrene calibration.

The steric exclusion chromatography method of measurement using a polystyrene calibration is described in Fontanille, M .; Gnanou, Y., Chemistry and physico-chemistry of polymers. 2nd ed .; Dunod: 2010; p 546 ).

∘ Compound A2 diester boronic

dans laquelle :

• w₁ et w₂, identiques ou différents sont des nombres entiers choisis entre 0 et 1,
• R₄, R₅, R₆ et R₇, identiques ou différents, sont choisis parmi le groupe formé par l'hydrogène et un groupe hydrocarboné ayant de 1 à 24 atomes de carbone, de préférence de 4 à 18 atomes de carbone, de préférence de 6 à 14 atomes de carbone ;
• L est un groupement de liaison divalent et choisi parmi le groupe formé par un aryle en C₆-C₁₈, un aralkyle en C₇-C₂₄ et une chaîne hydrocarbonée en C₂-C₂₄, de préférence un aryle en C₆-C₁₈.

In one embodiment of the composition of the invention, the compound A2 comprising two boronic ester functions has the general formula (III):

in which :

• w ₁ and w ₂ , identical or different, are integers selected from 0 to 1,
• R ₄ , R ₅ , R ₆ and R ₇ , which are identical or different, are chosen from the group formed by hydrogen and a hydrocarbon group having from 1 to 24 carbon atoms, preferably from 4 to 18 carbon atoms, preferably from 6 to 14 carbon atoms;
• L is a divalent linking group and selected from the group consisting of a C ₆ -C ₁₈ aryl, a C ₇ -C ₂₄ aralkyl and a C ₂ -C ₂₄ hydrocarbon chain, preferably a C ₆ -C ₆ aryl; C ₁₈ .

By "hydrocarbon group having 1 to 24 carbon atoms" is meant a linear or branched alkyl or alkenyl group having from 1 to 24 carbon atoms. Preferably, the hydrocarbon group comprises from 4 to 18 carbon atoms, preferably from 6 to 14 carbon atoms. Preferably, the hydrocarbon group is a linear alkyl.

By "C ₂ -C ₂₄ hydrocarbon chain" is meant a linear or branched alkyl or alkenyl group comprising from 2 to 24 carbon atoms. Preferably, the hydrocarbon chain is a linear alkyl group. Preferably the hydrocarbon chain comprises from 6 to 16 carbon atoms.

• w₁ et w₂, identiques ou différents sont des nombres entiers choisis entre 0 et 1;
• R₄ et R₆ sont identiques et sont des atomes d'hydrogène ;
• R₅ et R₇ sont identiques et sont un groupe hydrocarboné, de préférence un alkyle linéaire, ayant de 1 à 24 atomes de carbone, de préférence de 4 à 18 atomes de carbone, de préférence de 6 à 16 atomes de carbone ;
• L est un groupement de liaison divalent et est un aryle en C₆-C₁₈, de préférence le phényle.

In one embodiment of the invention, the compound A2 is a compound of the general formula (III) above in which:

• w ₁ and w ₂ , identical or different, are integers selected from 0 to 1;
• R ₄ and R ₆ are the same and are hydrogen atoms;
• R ₅ and R ₇ are identical and are a hydrocarbon group, preferably a linear alkyl, having from 1 to 24 carbon atoms, preferably from 4 to 18 carbon atoms, preferably from 6 to 16 carbon atoms;
• L is a divalent linking group and is a C ₆ -C ₁₈ aryl, preferably phenyl.

avec w₁,w₂ L, R₄, R₅, R₆ et R₇, tels que définis ci-dessus.The boronic diester A2 compound of formula (III) as described above is obtained by a condensation reaction between a boronic acid of general formula (III-a) and diol functions of the compounds of general formula (III-b) and (III-c) according to reaction scheme 4 below:

with w ₁ , w ₂ L, R ₄ , R ₅ , R ₆ and R ₇ , as defined above.

Indeed, by condensation of the boronic acid functions of the compound (III-a) with diols functions of the compounds of formula (III-b) and of formula (III-c), one obtains compounds having two functions boronic esters (compound of formula (III)). This step is carried out according to means well known to those skilled in the art.

In the context of the present invention, the compound of general formula (III-a) is dissolved, in the presence of water, in a polar solvent such as acetone. The presence of water makes it possible to displace the chemical equilibria between the boronic acid molecules of formula (III-a) and the boroxin molecules obtained from the boronic acids of formula (III-a). Indeed, it is well known that boronic acids can spontaneously form boroxine molecules at room temperature. However, the presence of boroxin molecules is undesirable in the context of the present invention.

The condensation reaction is carried out in the presence of a dehydrating agent such as magnesium sulfate. This agent makes it possible to trap the water molecules initially introduced as well as those released by the condensation between the compound of formula (III-a) and the compound of formula (III-b) and between the compound of formula (III- a) and the compound of formula (III-c).

In one embodiment, the compound (III-b) and the compound (III-c) are identical.

Those skilled in the art can adapt the amounts of reagents of formula (III-b) and / or (III-c) and of formula (III-a) to obtain the product of formula (III).

• Compound A2 boronic ester copolymer

In another embodiment of the composition of the invention, the compound A2 comprising at least two boronic ester functions is a boronic ester random copolymer resulting from the copolymerization of at least one monomer M3 of formula (IV) as described herein. below with at least one M4 monomer of formula (V) as described below.

✔ M3 Monomer of formula (IV)

dans laquelle :

• t est un nombre entier égal à 0 ou 1 ;
• u est un nombre entier égal à 0 ou 1 ;
• M et R₈ sont des groupements de liaison divalent, identiques ou différents, et sont choisis parmi le groupe formé par un aryle en C₆-C₁₈, un aralkyle en C₇-C₂₄ et alkyle en C₂-C₂₄, de préférence un aryle en C₆-C₁₈,
• X est une fonction choisie parmi le groupe formé par -O-C(O)-, -C(O)-O-, -C(O)-N(H)-, -N(H)-C(O)-, -S-, -N(H)-, -N(R'₄)- et -O- avec R'₄ une chaîne hydrocarbonée comprenant de 1 à 15 atomes de carbone;
• R₉ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃; de préférence -H et -CH₃;
• R₁₀ et R₁₁, identiques ou différents, sont choisis parmi le groupe formé par l'hydrogène et une chaîne hydrocarbonée ayant de 1 à 24 atomes de carbone, de préférence entre 4 et 18 atomes de carbone, de préférence entre 6 et 12 atomes de carbone.

The monomer M3 of the boronic ester random copolymer compound A2 has the general formula (IV) in which:

in which :

• t is an integer equal to 0 or 1;
• u is an integer equal to 0 or 1;
• M and R ₈ are divalent linking groups, which may be identical or different, and are chosen from the group formed by a C ₆ -C ₁₈ aryl, a C ₇ -C ₂₄ aralkyl and a C ₂ -C ₂₄ alkyl, preferably a C ₆ -C ₁₈ aryl,
• X is a function chosen from the group formed by -OC (O) -, -C (O) -O-, -C (O) -N (H) -, -N (H) -C (O) -, -S-, -N (H) -, -N (R ' ₄ ) - and -O- with R' ₄ a hydrocarbon chain comprising from 1 to 15 carbon atoms;
• R ₉ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ ; preferably -H and -CH ₃ ;
• R ₁₀ and R ₁₁ , which may be identical or different, are chosen from the group formed by hydrogen and a hydrocarbon chain containing from 1 to 24 carbon atoms, preferably from 4 to 18 carbon atoms, preferably from 6 to 12 atoms of carbon.

By "C ₂ -C ₂₄ alkyl" is meant a saturated hydrocarbon chain, linear or branched, comprising from 2 to 24 carbon atoms. Preferably, the hydrocarbon chain is linear. Preferably the hydrocarbon chain comprises from 6 to 16 carbon atoms.

By "hydrocarbon chain comprising 1 to 15 carbon atoms" is meant a linear or branched alkyl or alkenyl group comprising from 1 to 15 carbon atoms. Preferably, the hydrocarbon chain is a linear alkyl group. Preferably, it comprises from 1 to 8 carbon atoms.

By "hydrocarbon chain comprising 1 to 24 carbon atoms" is meant a linear or branched alkyl or alkenyl group comprising from 1 to 24 carbon atoms. Preferably, the hydrocarbon chain is a linear alkyl group. Preferably, it comprises from 4 to 18 carbon atoms, preferably from 6 to 12 carbon atoms.

• t est un nombre entier égal à 0 ou 1 ;
• u est un nombre entier égal à 0 ou 1 ;
• M et R₈ sont des groupements de liaison divalents et sont différents, M est un aryle en C₆-C₁₈, de préférence le phényle, R₈ est un aralkyle en C₇-C₂₄, de préférence le benzyle ;
• X est une fonction choisie parmi le groupe formé par -O-C(O)-, -C(O)-O-, -C(O)-N(H)- et -O-, de préférence -C(O)-O- ou -O-C(O)- ;
• R₉ est choisi parmi le groupe formé par -H, -CH₃, de préférence -H;
• R₁₀ et R₁₁ sont différents, l'un des groupes R₁₀ ou R₁₁ est H et l'autre groupe R₁₀ ou R₁₁ est une chaîne hydrocarbonée, de préférence un groupe alkyle linéaire, ayant de 1 à 24 atomes de carbone, de préférence entre 4 et 18 atomes de carbone, de préférence entre 6 et 12 atomes de carbone.

In one embodiment of the invention, the monomer M3 has the general formula (IV) in which:

• t is an integer equal to 0 or 1;
• u is an integer equal to 0 or 1;
• M and R ₈ are divalent linking groups and are different, M is a C ₆ -C ₁₈ aryl, preferably phenyl, R ₈ is a C ₇ -C ₂₄ aralkyl, preferably benzyl;
• X is a function chosen from the group formed by -OC (O) -, -C (O) -O-, -C (O) -N (H) - and -O-, preferably -C (O) - O- or -OC (O) -;
• R ₉ is selected from the group consisting of -H, -CH ₃ , preferably -H;
• R ₁₀ and R ₁₁ are different, one of R ₁₀ or R ₁₁ is H and the other R ₁₀ or R ₁₁ is a hydrocarbon chain, preferably a linear alkyl group having 1 to 24 carbon atoms preferably between 4 and 18 carbon atoms, preferably between 6 and 12 carbon atoms.

✔ Synthesis of the monomer M3 of formula (IV)

In all the schemes set forth below, unless otherwise indicated, the variables R ₁₀ , R ₁₁ , M, u, t, X, R ₈ , R ' ₄ and R ₉ have the same definition as in formula (IV) ci -above.

The monomers M3 of formula (IV) are obtained in particular from a preparation process comprising at least one step of condensation of a boronic acid of general formula (IV-f) with a diol compound of general formula (IV-g ) according to reaction scheme 5 below:

In fact, by condensation of the boronic acid functions of the compound of formula (IV-f) with diol functions of the compounds of formula (IV-g), a boronic ester compound of formula (IV) is obtained. This step is carried out according to methods well known to those skilled in the art.

In the context of the present invention, the compound of general formula (IV-f) is dissolved, in the presence of water, in a polar solvent such as acetone. The condensation reaction is carried out in the presence of a dehydrating agent, such as magnesium sulfate.

The compounds of formula (IV-g) are commercially available from the following suppliers: Sigma-Aldrich® and TCI®

avec

• z un nombre entier égal à 0 ou 1 ;
• R₁₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃ ;
• u, X, M, R₈ et R₉ tels que définis ci-dessus.

The compound of formula (IV-f) is obtained directly from the compound of formula (IV-e) by hydrolysis according to the following reaction scheme 6:

with

• z an integer equal to 0 or 1;
• R ₁₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ ;
• u, X, M, R ₈ and R ₉ as defined above.

avec

• z, R₁₂, M, R'₄, R₉ et R₈ tels que définis ci-dessus ;
  et dans ce schéma lorsque :
  • X représente -O-C(O)-, alors Y₄ représente une fonction alcool -OH ou un atome d'halogène, de préférence le chlore ou le brome et Y₅ est une fonction acide carboxylique -C(O)-OH ;
  • X représente -C(O)-O-, alors Y₄ représente une fonction acide carboxylique -C(O)-OH et Y₅ est une fonction alcool -OH ou un atome d'halogène, et de préférence le chlore ou le brome;
  • X représente -C(O)-N(H)-, alors Y₄ représente une fonction acide carboxylique -C(O)-OH ou une fonction -C(O)-Hal, et Y₅ est une fonction amine NH₂ ;
  • X représente -N(H)-C(O)-, alors Y₄ représente une fonction amine NH₂ et Y₅ est une fonction acide carboxylique -C(O)-OH ou une fonction -C(O)-Hal ;
  • X représente -S-, alors Y₄ est un atome d'halogène et Y₅ est une fonction thiol -SH ou bien Y₄ est une fonction thiol -SH et Y₅ est un atome d'halogène;
  • X représente -N(H)-, alors Y₄ est un atome d'halogène et Y₅ est une fonction amine -NH₂ ou bien Y₄ est une fonction amine -NH₂ et Y₅ est un atome d'halogène;
  • X représente -N(R'₄)-, alors Y₄ est un atome d'halogène et Y₅ est une fonction amine -N(H)(R'₄) ou bien Y₄ est une fonction amine -N(H)(R'₄) et Y₅ est un atome d'halogène;
  • X représente -O-, alors Y₄ est un atome d'halogène et Y₅ est une fonction alcool -OH ou bien Y₄ est une fonction alcool -OH et Y₅ est un atome d'halogène.

The compound of formula (IV-e) is obtained by a condensation reaction of a compound of formula (IV-c) with at least one compound of formula (IV-d) according to the following reaction scheme 7:

with

• z, R ₁₂ , M, R ' ₄ , R ₉ and R ₈ as defined above;
  and in this scheme when:
  • X represents -OC (O) -, then Y ₄ represents an alcohol function -OH or a halogen atom, preferably chlorine or bromine and Y ₅ is a carboxylic acid function -C (O) -OH;
  • X represents -C (O) -O-, then Y ₄ represents a carboxylic acid function -C (O) -OH and Y ₅ is an alcohol function -OH or a halogen atom, and preferably chlorine or bromine ;
  • X represents -C (O) -N (H) -, then Y ₄ represents a carboxylic acid function -C (O) -OH or a -C (O) -Hal function, and Y ₅ is an amine NH _{2 function} ;
  • X represents -N (H) -C (O) -, then Y ₄ represents an amine NH ₂ function and Y ₅ is a carboxylic acid function -C (O) -OH or a -C (O) -Hal function;
  • X is -S-, then Y ₄ is a halogen atom and Y ₅ is a thiol -SH function or Y ₄ is a thiol -SH function and Y ₅ is a halogen atom;
  • X is -N (H) -, then Y ₄ is a halogen atom and Y ₅ is an amine -NH ₂ function or Y ₄ is an amine -NH ₂ function and Y ₅ is a halogen atom;
  • X represents -N (R ' ₄ ) -, then Y ₄ is a halogen atom and Y ₅ is an amine function -N (H) (R' ₄ ) or Y ₄ is an amine function -N (H) (R ' ₄ ) and Y ₅ is a halogen atom;
  • X is -O-, then Y ₄ is a halogen atom and Y ₅ is an alcohol function -OH or Y ₄ is an alcohol function -OH and Y ₅ is a halogen atom.

These esterification, etherification, thioetherification, alkylation or condensation reactions between an amine function and a carboxylic acid function are well known in the art. the skilled person. Those skilled in the art can therefore choose, depending on the chemical nature of the Y ₁ and Y _{2 groups,} the reaction conditions to obtain the compound of formula (IV-e).

The compounds of formula (IV-d) are commercially available from the suppliers: Sigma-Aldrich® and TCI®

avec M, Y₄, z et R₁₂ tels que définis ci-dessus,The compound of formula (IV-c) is obtained by a condensation reaction between a boronic acid of formula (IV-a) with at least one diol compound of formula (IV-b) according to the following reaction scheme 8:

with M, Y ₄ , z and R ₁₂ as defined above,

Among the compounds of formula (IV-b), the one in which R ₁₂ is methyl and z = 0 is preferred.

The compounds of formula (IV-a) and (IV-b) are commercially available from the following suppliers: Sigma-Aldrich®, Alfa Aesar® and TCI®.

✔ M4 Monomer of general formula (V):

dans laquelle :

• R₁₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃, de préférence -H et -CH₃ ;
• R₁₃ est choisi parmi le groupe formé par un aryle en C₆-C₁₈, un aryle en C₆-C₁₈ substitué par un groupement R'₁₃, -C(O)-O-R'_13; -O-R'₁₃, -S-R'₁₃ et -C(O)-N(H)-R'₁₃ avec R'₁₃ un groupe alkyle en C₁-C₂₅.

The monomer M4 of the boronic ester random copolymer compound A2 has the general formula (V)

in which :

• R ₁₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ , preferably -H and -CH ₃ ;
• R ₁₃ is selected from the group consisting of a C ₆ -C ₁₈ aryl, C ₆ -C ₁₈ substituted by a group R _13, -C (O) -O-R _'13; -O-R _'13 , -S-R' ₁₃ and -C (O) -N (H) -R _'13 with R' ₁₃ a C ₁ -C ₂₅ alkyl group.

By "C ₁ -C ₂₅ alkyl group" is meant a saturated hydrocarbon chain, linear or branched, comprising from 1 to 25 carbon atoms. Preferably, the hydrocarbon chain is linear.

By "C ₆ -C ₁₈ aryl group substituted by a group R _13" is meant an aromatic hydrocarbon compound comprising from 6 to 18 carbon atoms, at least one carbon atom of the aromatic ring is substituted by a C 1 -C 4 alkyl group. ₁ -C ₂₅ as defined above.

dans laquelle :

• R₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃, de préférence -H et -CH₃ ;
• R'₁₃ un groupe alkyle en C₁-C₂₅, de préférence un alkyle linéaire en C₁-C₂₅, de manière encore plus préféré un alkyle linéaire en C₅-C₁₅.

Among the monomers of formula (V), the monomers corresponding to formula (VA) are among the preferred ones:

in which :

• R ₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ , preferably -H and -CH ₃ ;
• R _{'13 is} a C ₁ -C ₂₅ alkyl group, preferably a linear C ₁ -C ₂₅ alkyl, even more preferably a linear C ₅ -C ₁₅ alkyl.

✔ Obtaining the M4 monomer:

The monomers of formulas (V) and (V-A) are well known to those skilled in the art. They are marketed by Sigma-Aldrich® and TCI®

✔ Synthesis of compound A2 random copolymer boronic ester

Those skilled in the art are able to synthesize the boronic ester statistical copolymers using his general knowledge. The copolymerization can be initiated in bulk or in solution in an organic solvent with compounds generating free radicals. For example, the boronic ester random copolymers are obtained by the known methods of radical copolymerization, in particular controlled such as the method called controlled radical polymerization controlled by reversible addition-fragmentation chain transfer (in English: Reversible Addition-Fragmentation Chain Transfer (RAFT) ) and the method called Atom Transfer Radical Polymerization (ARTP). Conventional radical polymerization and telomerization can also be employed to prepare the copolymers of the invention ( Moad, G .; Solomon, DH, The Chemistry of Radical Polymerization. 2nd ed .; Elsevier Ltd: 2006; p 639 ; Matyaszewski, K .; Davis, TP Handbook of Radical Polymerization; Wiley-Interscience: Hoboken, 2002; p 936 )

1. i) un premier monomère M3 de formule générale (IV) :
   
   dans laquelle :
   • t est un nombre entier égal à 0 ou 1 ;
   • u est un nombre entier égal à 0 ou 1 ;
   • M et R₈ sont des groupements de liaison divalents, identiques ou différents, et sont choisis parmi le groupe formé par un aryle en C₆-C₁₈, un aralkyle en C₇-C₂₄ et un alkyle en C₂-C₂₄, de préférence un aryle en C₆-C₁₈ ;
   • X est une fonction choisie parmi le groupe formé par -O-C(O)-, -C(O)-O-, -C(O)-N(H)-, -N(H)-C(O)-, -S-, -N(H)-, -N(R'₄)- et -O- avec R'₄ une chaîne hydrocarbonée comprenant de 1 à 15 atomes de carbone;
   • R₉ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃ ; de préférence -H et -CH₃;
   • R₁₀ et R₁₁, identiques ou différents, sont choisis parmi le groupe formé par l'hydrogène et une chaîne hydrocarbonée ayant de 1 à 24 atomes de carbone, de préférence entre 4 et 18 atomes de carbone, de préférence entre 6 et 12 atomes de carbone ;
2. ii) au moins un second monomère M4 de formule générale (V) :
   
   dans laquelle :
   • R₁₂ est choisi parmi le groupe formé par -H, -CH₃ et -CH₂-CH₃, de préférence -H -CH₃ ;
   • R₁₃ est choisi parmi le groupe formé par un aryle en C₆-C₁₈, un aryle en C₆-C₁₈ substitué par un groupement R'₁₃, -C(O)-O-R'_13; -O-R'₁₃, -S-R'₁₃ et -C(O)-N(H)-R'₁₃ avec R'₁₃ un groupe alkyle en C₁-C₂₅.
3. iii) au moins une source de radicaux libres.

Thus another object of the present invention is a method for preparing a boronic ester statistical copolymer, said process comprising at least one polymerization step (a) in which at least:

1. i) a first monomer M3 of general formula (IV):
   
   in which :
   • t is an integer equal to 0 or 1;
   • u is an integer equal to 0 or 1;
   • M and R ₈ are divalent linking groups, which are identical or different, and are chosen from the group formed by a C ₆ -C ₁₈ aryl, a C ₇ -C ₂₄ aralkyl and a C ₂ -C ₂₄ alkyl, preferably a C ₆ -C ₁₈ aryl;
   • X is a function chosen from the group formed by -OC (O) -, -C (O) -O-, -C (O) -N (H) -, -N (H) -C (O) -, -S-, -N (H) -, -N (R ' ₄ ) - and -O- with R' ₄ a hydrocarbon chain comprising from 1 to 15 carbon atoms;
   • R ₉ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ ; preferably -H and -CH ₃ ;
   • R ₁₀ and R ₁₁ , which may be identical or different, are chosen from the group formed by hydrogen and a hydrocarbon chain containing from 1 to 24 carbon atoms, preferably from 4 to 18 carbon atoms, preferably from 6 to 12 atoms of carbon ;
2. ii) at least one second monomer M4 of general formula (V):
   
   in which :
   • R ₁₂ is selected from the group consisting of -H, -CH ₃ and -CH ₂ -CH ₃ , preferably -H -CH ₃ ;
   • R ₁₃ is selected from the group consisting of a C ₆ -C ₁₈ aryl, C ₆ -C ₁₈ substituted by a group R _13, -C (O) -O-R _'13; -O-R _'13 , -S-R' ₁₃ and -C (O) -N (H) -R _'13 with R' ₁₃ a C ₁ -C ₂₅ alkyl group.
3. iii) at least one source of free radicals.

In one embodiment, the method may further comprise iv) at least one chain transfer agent.

The preferences and definitions described for general formulas (IV) and (V) also apply to the process.

Radical sources and transfer agents are those which have been described for the synthesis of polydiol random copolymers. The preferences described for radical sources and transfer agents also apply to this process.

✔ Properties of A2 compounds boronic ester random copolymers

Advantageously, the chain formed by the linking of the groups R ₁₀ , M, (R ₈ ) _u with u, an integer equal to 0 or 1, and X of the monomer M 3 of general formula (IV) has a total number of carbon atoms ranging from 8 to 38, preferably from 10 to 26 carbon atoms.

Advantageously, the side chains of the boronic ester random copolymer have an average length greater than 8 carbon atoms, preferably ranging from 11 to 16 carbon atoms. This chain length makes it possible to solubilize the boronic ester random copolymer in a hydrophobic medium. By "average side chain length" is meant the average side chain length of each monomer constituting the copolymer. The person skilled in the art knows how to obtain this average length by appropriately selecting the types and the ratio of monomers constituting the boronic ester statistical copolymer.

Advantageously, the boronic ester statistical copolymer has a molar percentage of monomer of formula (IV) ranging from 0.25 to 20%, preferably from 1 to 10%.

Advantageously, the boronic ester statistical copolymer has a molar percentage of monomer of formula (IV) ranging from 0.25 to 20%, preferably from 1 to 10% and a molar percentage of monomer of formula (V) ranging from 80 to 99 , 75%, preferably 90 to 99%.

Advantageously, the boronic ester statistical copolymer has a number-average degree of polymerization ranging from 50 to 1500, preferably from 80 to 800.

Advantageously, the boronic ester statistical copolymer has a polydispersity index (Ip) ranging from 1.04 to 3.54; preferably ranging from 1.10 to 3.10. These values are obtained by size exclusion chromatography using tetrahydrofuran as eluent and a polystyrene calibration.

Advantageously, the boronic ester statistical copolymer has a number-average molecular weight ranging from 10,000 to 200,000 g / mol, preferably from 25,000 to 100,000 g / mol. These values are obtained by size exclusion chromatography using tetrahydrofuran as eluent and a polystyrene calibration.

✔ Characteristics of the new compositions of the invention

The new compositions of the invention have the advantage of being thermoreversibly crosslinkable.

The polydiols random copolymers A1, especially those resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and compounds A2 as defined above have the advantage of being associative and of exchanging chemical bonds thermoreversibly, especially in a hydrophobic medium, in particular an apolar hydrophobic medium.

Under certain conditions, the polydiols random copolymers A1, in particular those resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) ) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and compounds A2 as defined above can be crosslinked.

Polydiols random copolymers A1, especially those resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one a monomer of formula (II-A1) and at least one monomer of formula (II-A2), and the compounds A2 also have the advantage of being exchangeable.

The term "associative" is understood to mean that covalent boronic ester-type chemical bonds are established between the polydiols random copolymers A1, in particular those resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and the compounds A2 comprising at least minus two boronic ester functions. The figure 4 illustrates associative polymers. According to the functionality of polydiols A1, especially those resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least minus one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and compounds A2 and according to the composition of the mixtures, the formation of covalent bonds between polydiols A1 and compounds A2 may lead to no to the formation of a three-dimensional polymeric network.

By "chemical bond" is meant a covalent chemical bond of the boronic ester type.

avec :

• R un groupe chimique du composé A2,
• le rond hachuré symbolise le reste de la structure chimique du composé A2,
• le rectangle quadrillé symbolise le reste de la structure chimique du polymère statistique polydiol A1, notamment celui résultant de la copolymérisation d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A) ou d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A1) et au moins un monomère de formule (II-A2).

By "exchangeable" is meant that the compounds are capable of exchanging chemical bonds between them without the total number of chemical functions being changed. The boronic ester bonds of the compounds A2 as well as the boronic ester bonds formed by combination of the polydiols random copolymers A1, in particular those resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A ) or at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and compounds A2 can be exchanged with diol functions present in the composition to form new boronic esters and new diol functions without the total number of boronic ester functions and diol functions being affected. The chemical exchange reaction (transesterification) is illustrated in the diagram next reaction 9:

with:

• R a chemical group of the compound A2,
• the hatched round symbolizes the rest of the chemical structure of compound A2,
• the grid rectangle symbolizes the remainder of the chemical structure of the polydiol A1 random polymer, in particular that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or at least one a monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2).

The boronic ester bonds of the compounds A2 as well as the boronic ester bonds formed by combination of the polydiols random copolymers A1, in particular those resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A ) or at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and compounds A2 can also be exchanged to form new boronic esters without affecting the total number of boronic ester functions. This other process of exchange of chemical bonds is carried out by metathesis reaction, via successive exchanges of boronic ester functions in the presence of diols; this process is illustrated in figure 9 . The polydiol random copolymer A1-1, which was associated with the polymer A2-1, exchanged a boronic ester bond with the boronic ester random copolymer A2-2. The polydiol random copolymer A1-2, which was in association with the A2-2 polymer, exchanged a boronic ester bond with the boronic ester random copolymer A2-1; the total number of boronic ester bond in the composition being unchanged and is 4. The A1-1 copolymer is then combined with both the A2-1 polymer and the A2-2 copolymer. The copolymer A1-2 is then combined with both the copolymer A2-1 and with the copolymer A2-2.

Another chemical link exchange process is illustrated in figure 9 in which it can be seen that the polydiol random copolymer A1-1, which was associated with the A2-1 polymer, exchanged two boronic ester bonds with the boronic ester random copolymer A2-2. The polydiol random copolymer A1-2, which was in association with the A2-2 polymer, exchanged two boronic ester bonds with the boronic ester random copolymer A2-1; the total number of boronic ester bond in the composition being unchanged and is equal to 4. The A1-1 copolymer is then combined with the A2-2 polymer. The copolymer A1-2 is then with the polymer A2-1. The A2-1 copolymer was exchanged with the A2-2 polymer.

By "crosslinked" is meant a copolymer in the form of a network obtained by the establishment of bridges between the macromolecular chains of the copolymer. These interconnected chains are for the most part distributed in the three dimensions of space. A crosslinked copolymer forms a three-dimensional network. In practice, the formation of a copolymer network is ensured by a solubility test. It can be ensured that a network of copolymers has been formed by placing the copolymer network in a known solvent to dissolve the uncrosslinked copolymers of the same chemical nature. If the copolymer swells instead of dissolving, the person skilled in the art knows that a network has been formed. The figure 3 illustrates this solubility test.

By "crosslinkable" is meant a copolymer capable of being crosslinked.

By "reversibly crosslinked" is meant a crosslinked copolymer whose bridges are formed by a reversible chemical reaction. The reversible chemical reaction can move in one direction or another, resulting in a change in structure of the polymer network. The copolymer can pass from an uncrosslinked initial state to a crosslinked state (three-dimensional network of copolymers) and from a crosslinked state to an uncrosslinked initial state. In the context of the present invention, the bridges that form between the copolymer chains are labile. These bridges can form or exchange through a chemical reaction that is reversible. In the context of the present invention, the reversible chemical reaction is a transesterification reaction between diol functional groups of a random copolymer (copolymer A1, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one a monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2)) and ester functions boronic compound A2. The bridges formed are boronic ester type bonds. These boronic ester bonds are covalent and labile because of the reversibility of the transesterification reaction.

By "thermoreversible crosslinked" is meant a copolymer crosslinked by a reversible reaction whose displacement in one direction or the other direction is controlled by the temperature. The thermoreversible crosslinking mechanism of the composition of the invention is schematically presented in figure 4 . Unexpectedly, the applicant has observed that at low temperature, the polydiol copolymer A1, in particular that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one a monomer of formula (II-A2) (symbolized by the copolymer carrying A functions on the figure 4 ), is not or only slightly crosslinked by the boronic ester compounds A2 (symbolized by the compound carrying B functions on the figure 4 ). As the temperature increases, the diol functions of the copolymer react with the boronic ester functions of compound A2 by a transesterification reaction. Polydiols random copolymers A1, especially those resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one a monomer of formula (II-A1) and at least one monomer of formula (II-A2), and the compounds A2 comprising at least two boronic ester functions then bind together and can be exchanged. According to the functionality of polydiols A1, especially those resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least minus one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and compounds A2 and according to the composition of the mixtures, a gel can be formed in the medium, especially when the medium is nonpolar . When the temperature decreases again, the boronic ester bonds between the polydiols random copolymers A1, in particular those resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and the A2 compounds are broken, and if necessary, the composition loses its gelled character.

The amount of boronic ester bonds (or boronic ester bond) which can be established between the polydiols random copolymers A1 and the A2 compounds is adjusted by those skilled in the art by means of an appropriate selection of the polydiol A1 random copolymer, in particular the resulting one. of the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and compound A2 and the composition of the mixture.

In addition, a person skilled in the art knows how to select the structure of the compound A2 as a function of the structure of the random copolymer A1, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula ( II-A) or at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2). Preferably, when in the random copolymer A1, in particular that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I ) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), comprising at least one monomer M1 in which y = 1, then the compound A2 of formula general (III) or the copolymer A2 comprising at least one monomer M3 of formula (IV) will preferably be chosen with w ₁ = 1, w ₂ = 1 and t = 1, respectively.

Advantageously, the content of random copolymer A1, in particular that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2) in the composition ranges from 0.25% to 20% by weight relative to the total weight of the final composition, preferably from 1 to 10% by weight relative to the total weight of the final composition.

Advantageously, the content of compound A2 in the composition ranges from 0.25% to 20% by weight relative to the total weight of the final composition, preferably preferably from 0.5% to 10% by weight relative to the total weight of the composition. the final composition.

Preferably, the mass ratio between the polydiol A1 statistical compound, in particular that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and the compound A2 (ratio A1 / A2) in the composition ranges from 0.001 to 100, preferably from 0.05 to 20, even more preferably 0.1 to 10, more preferably 0.2 to 5.

In one embodiment of the invention, the sum of the masses of the random copolymer A1, in particular that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and of compound A2 is from 0.5 to 20% with respect to the total mass of the lubricating composition and the lubricating oil mass ranges from 80% to 99.5% relative to the total mass of the lubricating composition.

In one embodiment, the composition of the invention may further comprise a functional additive selected from the group consisting of detergents, anti-wear additives, extreme pressure additives, antioxidants, viscosity index improving polymers. , pour point improvers, defoamers, thickeners, anticorrosive additives, dispersants, friction modifiers and mixtures thereof.

∘ Functional additives

• soit chaque additif est ajouté isolément et séquentiellement dans la composition,
• soit l'ensemble des additifs est ajouté simultanément dans la composition, les additifs sont dans ce cas généralement disponibles sous forme d'un paquet, appelé paquet d'additifs.

The functional additive (s) which are added to the composition of the invention are chosen according to the end use of the lubricating composition. These additives can be introduced in two different ways:

• either each additive is added separately and sequentially into the composition,
• either the set of additives is added simultaneously in the composition, the additives are in this case generally available in the form of a package, called package of additives.

The functional additive or functional additive mixtures, when present, represent from 0.1 to 10% by weight relative to the total weight of the composition.

✔ The detergents:

These additives reduce the formation of deposits on the surface of the metal parts by dissolving the secondary products of oxidation and combustion. The detergents that can be used in the lubricant compositions according to the present invention are well known to those skilled in the art. The detergents commonly used in the formulation of lubricating compositions are typically anionic compounds having 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 preferably chosen from alkali metal or alkaline earth metal salts of carboxylic acids, sulphonates, salicylates and naphthenates, as well as the salts of phenates. The alkali and alkaline earth metals are preferably 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, we are dealing with so-called overbased detergents. The excess metal providing the overbased detergent character is in the form of oil insoluble metal salts, for example carbonate, hydroxide, oxalate, acetate, glutamate, preferably carbonate.

✔ Anti-wear additives and extreme pressure additives:

These additives protect the friction surfaces by forming a protective film adsorbed on these surfaces. There is a wide variety of anti-wear and extreme pressure additives. By way of illustration, mention may be made of phosphosulfur additives such as metal alkylthiophosphates, in particular zinc alkylthiophosphates, and more specifically zinc dialkyldithiophosphates or ZnDTPs, amine phosphates and polysulfides, especially sulfur-containing olefins and metal dithiocarbamates.

✔ Antioxidants:

These additives retard the degradation of the composition. The degradation of the composition may result in the formation of deposits, the presence of sludge, or an increase in the viscosity of the composition. Antioxidants act as free radical inhibitors or destroyers of hydroperoxides. Among the commonly used antioxidants are antioxidants of phenolic or amine type.

✔ The anticorrosions :

These additives cover the surface of a film that prevents access of oxygen to the surface of the metal. They can sometimes neutralize acids or certain chemicals to prevent metal corrosion. Illustrative examples include dimercaptothiadiazole (DMTD), benzotriazoles, phosphites (free sulfur capture).

✔ Viscosity index improvers:

These additives make it possible to guarantee a good cold behavior and a minimum viscosity at high temperature of the composition. By way of illustration, mention may be made, for example, of polymeric esters, copolymer olefins (OCP), homopolymers or copolymers of styrene, butadiene or isoprene and polymethacrylates (PMA).

✔ Pour Point Improvers:

These additives improve the cold behavior of the compositions by slowing down the formation of paraffin crystals. They are, for example, alkyl polymethacrylates, polyacrylates, polyarylamides, polyalkylphenols, polyalkylnaphthalenes and alkylated polystyrenes.

✔ Defoamers :

These additives have the effect of countering the effect of detergents. By way of illustration, mention may be made of polymethylsiloxanes and polyacrylates.

✔ Thickeners:

Thickeners are additives used mainly for industrial lubrication and make it possible to formulate lubricants of higher viscosity than engine lubricating compositions. By way of illustration, mention may be made of polysiobutenes having a molar mass by weight of 10,000 to 100,000 g / mol.

✔ Dispersants:

These additives ensure the maintenance in suspension and the evacuation of insoluble solid contaminants constituted by the by-products of oxidation which are formed during the use of the composition. By way of illustration, mention may be made, for example, of succinimides, PIBs (polyisobutene) succinimides and Mannich bases.

✔ Friction modifiers;

These additives improve the coefficient of friction of the composition. By way of illustration, mention may be made of molybdenum dithiocarbamate, amines having at least one chain hydrocarbon of at least 16 carbon atoms, esters of fatty acids and polyols such as esters of fatty acids and glycerol, in particular glycerol monooleate.

✔ Process for preparing the novel compositions of the invention

• prélever une quantité voulue d'une solution comprenant le copolymère statistique polydiol A1 tel que défini ci-dessus, notamment celui résultant de la copolymérisation d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A) ou d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A1) et au moins un monomère de formule (II-A2) ;
• prélever une quantité voulue d'une solution comprenant le composé A2 tel que défini ci-dessus ;
• mélanger les deux solutions prélevées dans une huile de base lubrifiante pour obtenir la composition de l'invention.

The new compositions of the invention are prepared by means well known to those skilled in the art. For example, it suffices for the person skilled in the art to:

• withdrawing a desired quantity of a solution comprising the polydiol random copolymer A1 as defined above, in particular that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2);
• withdrawing a desired amount of a solution comprising compound A2 as defined above;
• mixing the two solutions taken in a lubricating base oil to obtain the composition of the invention.

• le pourcentage molaire de monomère M1 portant des fonctions diols dans le copolymère statistique polydiol A1, notamment celui résultant de la copolymérisation d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A) ou d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A1) et au moins un monomère de formule (II-A2) ;
• le pourcentage molaire de monomère M3 portant des fonctions ester boronique dans le copolymère statistique ester boronique A2,
• la longueur moyenne des chaînes latérales du copolymère statistique polydiol A1, notamment celui résultant de la copolymérisation d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A) ou d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A1) et au moins un monomère de formule (II-A2) ;
• la longueur moyenne des chaînes latérales du copolymère statistique ester boronique A2,
• la longueur du monomère M3 du copolymère statistique ester boronique A2,
• la longueur du composé diester boroniqueA2,
• le degré de polymérisation moyen des copolymères statistique polydiol A1, notamment celui résultant de la copolymérisation d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A) ou d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A1) et au moins un monomère de formule (II-A2), et des copolymères statistiques esters boroniques A2,
• le pourcentage massique du copolymère statistique polydiols A1, notamment celui résultant de la copolymérisation d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A) ou d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A1) et au moins un monomère de formule (II-A2),
• le pourcentage massique du composé diester boronique A2,
• le pourcentage massique du copolymère statistique ester boronique A2,

Those skilled in the art can also adjust the various parameters of the composition of the invention to obtain a crosslinkable composition. For example, a person skilled in the art knows how to adjust in particular:

• the molar percentage of monomer M1 bearing diol functions in the polydiol-A1 random copolymer, in particular that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or from at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2);
• the molar percentage of monomer M3 carrying boronic ester functions in the boronic ester random copolymer A2,
• the average length of the side chains of the polydiol A1 random copolymer, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2);
• the average side chain length of the boronic ester random copolymer A2,
• the length of the monomer M3 of the boronic ester random copolymer A2,
• the length of the boronic diester compound A2,
• the average degree of polymerization of the polydiol A1 random copolymers, in particular that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II) -A2), and boronic ester random copolymers A2,
• the weight percentage of the polydiols random copolymer A1, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2),
• the weight percentage of the boronic diester compound A2,
• the weight percentage of the boronic ester random copolymer A2,

✔ Use of the new compositions of the invention

Another object of the present invention is the use of the composition as defined above for lubricating a mechanical part.

The compositions of the invention are useful for lubricating the surfaces of parts that are conventionally found in an engine such as the pistons, segments, shirts system.

• 97% à 99,9% en poids d'une huile lubrifiante, et
• 0,1% à 3% en poids d'au moins un copolymère statistique A1, notamment celui résultant de la copolymérisation d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A) ou d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A1) et au moins un monomère de formule (II-A2), et au moins un composé A2 comprenant au moins deux fonctions esters boroniques tels que définis précédemment ;

la composition ayant une viscosité cinématique à 100°C mesurée selon la norme ASTM D445 allant de 3,8 à 26,1 cSt ; les pourcentages étant exprimés par rapport au poids total de la composition lubrifiante.Thus another object of the present invention is a composition for lubricating at least one engine comprising a composition resulting from the mixture of:

• 97% to 99.9% by weight of a lubricating oil, and
• 0.1% to 3% by weight of at least one random copolymer A1, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and at least one compound A2 comprising at least two boronic ester functions as defined previously;

the composition having a kinematic viscosity at 100 ° C measured according to ASTM D445 ranging from 3.8 to 26.1 cSt; the percentages being expressed relative to the total weight of the lubricant composition.

In a composition for lubricating at least one engine, at least one random copolymer A1, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or from at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and at least one compound A2 comprising at least two boronic ester functions as defined above can associate and exchange in a thermoreversible way; but they do not form three-dimensional networks. They are not crosslinked.

In one embodiment, the composition for lubricating at least one motor further comprises at least one functional additive selected from the group consisting of detergents, anti-wear additives, extreme pressure additives, additional antioxidants, anticorrosive additives, viscosity index improvers, dots improvers and the like. flow, antifoams, thickeners, dispersants, friction modifiers and mixtures thereof.

• 97% à 99,9% en poids d'une huile lubrifiante, et
• 0,1% à 3% en poids d'au moins un copolymère statistique A1, notamment celui résultant de la copolymérisation d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A) ou d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A1) et au moins un monomère de formule (II-A2), et au moins un composé A2 comprenant au moins deux fonctions esters boroniques tels que définis précédemment ;

la composition ayant une viscosité cinématique à 100°C mesurée selon la norme ASTM D445 allant de 3,8 à 26,1 cSt ; les pourcentages étant exprimés par rapport au poids total de la composition lubrifiante.In one embodiment of the invention, the composition for lubricating at least one engine consists essentially of a composition resulting from the mixture of:

• 97% to 99.9% by weight of a lubricating oil, and
• 0.1% to 3% by weight of at least one random copolymer A1, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and at least one compound A2 comprising at least two boronic ester functions as defined previously;

the composition having a kinematic viscosity at 100 ° C measured according to ASTM D445 ranging from 3.8 to 26.1 cSt; the percentages being expressed relative to the total weight of the lubricant composition.

• 82% à 99,8% en poids d'une huile lubrifiante, et
• 0,1% à 3% en poids d'au moins un copolymère statistique A1, notamment celui résultant de la copolymérisation d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A) ou d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A1) et au moins un monomère de formule (II-A2), et au moins un composé A2 comprenant au moins deux fonctions esters boroniques tels que définis précédemment ;
• 0,1% à 15% en poids d'au moins un additif fonctionnel choisi parmi le groupe formé par les détergents, les additifs anti-usure, les additifs extrême pression, les antioxydants supplémentaires, les additifs anticorrosion, les polymères améliorant l'indice de viscosité, les améliorants de point d'écoulement, les anti-mousse, les épaississants, les dispersants, les modificateurs de frottements et leurs mélanges ;

la composition ayant une viscosité cinématique à 100°C mesurée selon la norme ASTM D445 allant de 3,8 à 26,1 cSt; les pourcentages étant exprimés par rapport au poids total de la composition lubrifiante.In one embodiment of the invention, the composition for lubricating at least one engine consists essentially of a composition resulting from the mixture of:

• 82% to 99.8% by weight of a lubricating oil, and
• 0.1% to 3% by weight of at least one random copolymer A1, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and at least one compound A2 comprising at least two boronic ester functions as defined previously;
• 0.1% to 15% by weight of at least one functional additive selected from the group consisting of detergents, anti-wear additives, extreme pressure additives, additional antioxidants, anti-corrosion additives, index-improving polymers viscosity, pour point improvers, defoamers, thickeners, dispersants, friction modifiers and mixtures thereof;

the composition having a kinematic viscosity at 100 ° C measured according to ASTM D445 ranging from 3.8 to 26.1 cSt; the percentages being expressed relative to the total weight of the lubricant composition.

The definitions and preferences relating to lubricating oils, random copolymers A1, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or at least one monomer of formula (I) with minus one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and compounds A2 also apply to compositions for lubricating at least one engine.

Another object of the present invention is a composition for lubricating at least one transmission, such as manual or automatic gearboxes.

In a composition for lubricating at least one transmission, at least one random copolymer A1, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or from at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and at least one compound A2 comprising at least two boronic ester functions as defined above can associate and exchange in a thermoreversible way; but they do not form three-dimensional networks. They are not crosslinked.

• 85% à 99,5% en poids d'une huile lubrifiante, et
• 0,5% à 15% en poids d'au moins un copolymère statistique A1, notamment celui résultant de la copolymérisation d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A) ou d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A1) et au moins un monomère de formule (II-A2), et au moins un composé A2 comprenant au moins deux fonctions esters boroniques tels que définis précédemment ;

la composition ayant une viscosité cinématique à 100°C mesurée selon la norme ASTM D445 allant de 4,1 à 41 cSt; les pourcentages étant exprimés par rapport au poids total de la composition lubrifiante.Thus another object of the present invention is a composition for lubricating at least one transmission comprising a composition resulting from the mixture of:

• 85% to 99.5% by weight of a lubricating oil, and
• 0.5% to 15% by weight of at least one random copolymer A1, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and at least one compound A2 comprising at least two boronic ester functions as defined previously;

the composition having a kinematic viscosity at 100 ° C measured according to ASTM D445 ranging from 4.1 to 41 cSt; the percentages being expressed relative to the total weight of the lubricant composition.

In one embodiment, the composition for lubricating at least one transmission further comprises at least one functional additive selected from the group consisting of detergents, antiwear additives, extreme pressure additives, additional antioxidants, anticorrosion additives, viscosity index improver polymers, pour point improvers, defoamers, thickeners, dispersants, friction modifiers and mixtures thereof.

• 95% à 99,5% en poids d'une huile lubrifiante, et
• 0,5% à 15% en poids d'au moins un copolymère statistique A1, notamment celui résultant de la copolymérisation d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A) ou d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A1) et au moins un monomère de formule (II-A2), et au moins un composé A2 comprenant au moins deux fonctions esters boroniques tels que définis précédemment ;

la composition ayant une viscosité cinématique à 100°C mesurée selon la norme ASTM D445 allant de 4,1 à 41 cSt.In one embodiment of the invention, the composition for lubricating at least one transmission consists essentially of a composition resulting from the mixture of:

• 95% to 99.5% by weight of a lubricating oil, and
• 0.5% to 15% by weight of at least one random copolymer A1, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and at least one compound A2 comprising at least two boronic ester functions as defined previously;

the composition having a kinematic viscosity at 100 ° C measured according to ASTM D445 ranging from 4.1 to 41 cSt.

• 70% à 99,4% en poids d'une huile lubrifiante, et
• 0,5% à 15% en poids d'au moins un copolymère statistique A1, notamment celui résultant de la copolymérisation d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A) ou d'au moins un monomère de formule (I) avec au moins un monomère de formule (II-A1) et au moins un monomère de formule (II-A2), et au moins un composé A2 comprenant au moins deux fonctions esters boroniques tels que définis précédemment ;
• 0,1% à 15% en poids d'au moins moins un additif fonctionnel choisi parmi le groupe formé par les détergents, les additifs anti-usure, les additifs extrême pression, les antioxydants supplémentaires, les additifs anticorrosion, les polymères améliorant l'indice de viscosité, les améliorants de point d'écoulement, les anti-mousses, les épaississants, les dispersants, les modificateurs de frottements et leurs mélanges ;

la composition ayant une viscosité cinématique à 100°C mesurée selon la norme ASTM D445 allant de 4,1 à 41 cSt ; les pourcentages étant exprimés par rapport au poids total de la composition lubrifiante.In one embodiment of the invention, the lubricating composition for lubricating at least one transmission consists essentially of a composition resulting from mixing:

• 70% to 99.4% by weight of a lubricating oil, and
• 0.5% to 15% by weight of at least one random copolymer A1, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and at least one compound A2 comprising at least two boronic ester functions as defined previously;
• From 0.1% to 15% by weight of at least one functional additive selected from the group consisting of detergents, anti-wear additives, extreme pressure additives, additional antioxidants, anti-corrosion additives, polymers improving the viscosity number, pour point impreners, defoamers, thickeners, dispersants, friction modifiers and mixtures thereof;

the composition having a kinematic viscosity at 100 ° C measured according to ASTM D445 ranging from 4.1 to 41 cSt; the percentages being expressed relative to the total weight of the lubricant composition.

The definitions and preferences relating to lubricating oils, random copolymers A1, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and compounds A2 also apply to the compositions for lubricating at least one transmission.

The compositions of the invention can be used for engines or transmissions of light vehicles, trucks but also ships.

Another object of the present invention is a method of lubricating at least one mechanical part, in particular at least one motor or at least one transmission, said method comprising a step in which said mechanical part is brought into contact with at least one composition as defined above.

The definitions and preferences relating to lubricating oils, random copolymers A1, especially that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), and compounds A2 also apply to the method of lubricating at least one mechanical part.

Another subject of the present invention relates to a parent composition resulting from the mixture of at least at least one random copolymer A1 as defined above, in particular that resulting from the copolymerization of at least one monomer of formula (I) with at least one monomer of formula (II-A) or of at least one monomer of formula (I) with at least one monomer of formula (II-A1) and at least one monomer of formula (II-A2), at least a compound A2 comprising at least two boronic ester functions, at least one functional additive selected from the group consisting of detergents, anti-wear additives, extreme pressure additives, antioxidants, viscosity index improving polymers, improvers pour point, antifoams, thickeners, dispersants, friction modifiers and their mixtures.

By "mother composition" is meant a composition which a person skilled in the art can make daughter solutions by removing a certain amount of mother solution supplemented by the addition of a necessary quantity of diluent (solvent or other) to obtain a desired concentration. A daughter composition is thus obtained by dilution of a parent composition. In one embodiment, the lubricating compositions of the invention can be obtained by diluting in a lubricating oil, especially a Group I, Group II, Group III, Group IV, Group V API classification base oil. or a mixture thereof, the parent composition as defined above.

EXAMPLES

The following examples illustrate the invention without limiting it.

1 Synthesis of Statistical Copolymers A1 of the Invention Bearing Diol Function ∘ 1 . 1: From a monomer carrying a protected diol function in the form of ketal

In one embodiment, the random copolymer A1 of the invention is obtained according to the following reaction scheme:

1.1.1 Synthesis of the monomer M1 bearing a protected diol function in the form of ketal

The synthesis of a methacrylate monomer carrying a protected diol function in ketal form is carried out in two steps (steps 1 and 2 of the reaction scheme 10) according to the protocol below:

1 ^st step:

42.1 g (314 mmol) of 1,2,6-hexane triol (1,2,6-HexTri) are introduced into an IL flask. 5.88 g of molecular sieves (4 ° A) are added followed by 570 mL of acetone. 5.01 g (26.3 mmol) of para-toluenesulfonic acid (pTSA) are then slowly added. The reaction medium is stirred for 24 hours at room temperature. 4.48 g (53.3 mmol) of NaHCO ₃ are then added. The reaction medium is stirred for 3 hours at room temperature before being filtered. The filtrate is then concentrated under vacuum using a rotary evaporator until a suspension of white crystals is obtained. 500 ml of water are then added to this suspension. The solution thus obtained is extracted with 4 x 300 ml of dichloromethane. The organic phases are combined and dried over MgSO ₄ . The solvent is then completely evaporated under vacuum at 25 ° C. by means of a rotary evaporator.

2 ^th step:

The product thus obtained is then introduced into an IL flask surmounted by a dropping funnel. The glassware used was first dried overnight in a thermostatically controlled oven at 100 ° C. 500 ml of anhydrous dichloromethane are then introduced into the flask followed by 36.8 g (364 mmol) of triethylamine. A solution of 39.0 g (373 mmol) of methacryloyl chloride (MAC) in 50 mL of anhydrous dichloromethane is introduced into the dropping funnel. The flask is then placed in an ice bath to lower the temperature of the reaction medium to around 0 ° C. The methacryloyl chloride solution is then added dropwise with vigorous stirring. Once the methacryloyl chloride addition is complete, the reaction medium is left stirring for 1 hour at 0 ° C. and then 23 hours at room temperature. The reaction medium is then transferred into a 3 L Erlenmeyer flask and 1 L of dichloromethane is added. The organic phase is then successively washed with 4 × 300 ml of water, 6 × 300 ml of a 0.5 M aqueous hydrochloric acid solution, 6 × 300 ml of a saturated aqueous solution of NaHCO ₃ and new 4 × 300 mL of water. The organic phase is dried over MgSO ₄ , filtered and then concentrated under vacuum using a rotary evaporator to give 64.9 g (85.3% yield) of protected diol monomer in the form of a light yellow liquid. whose characteristics are as follows:
¹ H NMR (400 MHz, CDCl 3) δ: 6.02 (singlet, 1H), 5.47 (singlet, 1H), 4.08 (triplet, J = 6.8 Hz, 2H), 4.05-3 , 98 (multiplet, 1H), 3.96 (doublet of doublets, J = 6 Hz and J = 7.6 Hz, 1H), 3.43 (doublet of doublet, J = 7.2 Hz and J = 7, 2 Hz, 1H), 1.86 (doublet of doublets, J = 1.2 Hz and J = 1.6 Hz, 3H), 1.69-1.33 (multiplet, 6H), 1.32 (singlet, 3H), 1.27 (singlet, 3H).

1.1.2 Synthesis of methacrylate copolymers according to the invention carrying diol functions

• Copolymérisation de deux monomères méthacrylate d'alkyle avec un monomère méthacrylate porteur d'une fonction diol protégée sous forme de cétal ;
• Déprotection du copolymère.

The synthesis of the methacrylate copolymers carrying diol functions according to the invention is carried out in two steps (steps 3 and 4 of the reaction scheme 10):

• Copolymerization of two alkyl methacrylate monomers with a methacrylate monomer bearing a protected diol function in the form of a ketal;
• Deprotection of the copolymer.

More specifically, the synthesis of the copolymer is carried out according to the following protocol:
10.5 g (31.0 mmol) of stearyl methacrylate (StMA), 4.76 g (18.7 mmol) of lauryl methacrylate (LMA), 3.07 g (12.7 mmol) of methacrylate bearing a protected diol function in the form of a ketal obtained according to the protocol described in paragraph 1.1.1, 68.9 mg (0.253 mmol) of cumyl dithiobenzoate and 19.5 ml of anisole are introduced into a Schlenk tube of 100 ml. The reaction medium is stirred and 8.31 mg (0.0506 mmol) of azobisisobutyronitrile (AIBN) in solution in 85 .mu.l of anisole are introduced into the Schlenk tube. The reaction medium is then degassed for 30 minutes by bubbling argon before being heated to 65 ° C. for a duration of 16 hours. Schlenk's tube is placed in a bath of ice to stop the polymerization, then the polymer is isolated by precipitation in methanol, filtration and drying under vacuum at 30 ° C overnight.

A copolymer having a number-average molar mass ( M _n ) of 41,000 g / mol, a polydispersity index (Ip) of 1.22 and a number-average degree of polymerization (DP _n ) of 167 are thus obtained. values are respectively obtained by size exclusion chromatography using tetrahydrofuran as eluent and polystyrene calibration and by monitoring the conversion to monomers during the copolymerization.

The deprotection of the copolymer is carried out according to the following protocol:
7.02 g of copolymer containing about 20% protected diol function obtained previously are introduced into a 500 ml Erlenmeyer flask. 180 ml of dioxane are added and the reaction mixture is stirred at 30 ° C. 3 ml of a 1M aqueous solution of hydrochloric acid and then 2.5 ml of an aqueous solution of 35% hydrochloric acid are added dropwise. The reaction medium then becomes slightly opaque and 20 ml of THF are introduced to make the medium completely homogeneous and transparent. The reaction medium is then left stirring at 40 ° C. for 48 hours. The copolymer is recovered by precipitation in methanol, filtration and drying under vacuum at 30 ° C overnight.

A poly (alkyl methacrylate-co-alkyldiol methacrylate) copolymer containing about 20 mol% of M1 diol monomer units and having an average length of pendant alkyl chains of 13.8 carbon atoms is obtained.

∘ 1.2: From a monomer carrying a protected diol function in the form of a boronic ester

In another embodiment, the random copolymer A1 of the invention is obtained according to the following reaction scheme 11:

1.2.1 Synthesis of the monomer M1 bearing a protected diol function in the form of a boronic ester

The synthesis of a methacrylate monomer bearing a protected diol function in the form of an ester is carried out in two stages (steps 1 and 2 of Scheme 11) according to the following protocol:

1 ^st step:

Phenylboronic acid (PBA) 6.01 g (49.3 mmol) and 300 mL of acetone are added to a 500 mL beaker followed by 1.5 mL of water. The reaction medium is stirred and 6.07 g (45.2 mmol) of 1,2,6-hexanetriol are slowly added. An excess of magnesium sulphate is added to the reaction medium in order to trap the water initially introduced as well as the water released by the condensation between phenylboronic acid and 1,2,6-hexanetriol. The reaction medium is left stirring at ambient temperature for 30 minutes before being filtered and then concentrated under vacuum using a rotavapor.

2 ^th step:

The light yellow liquid thus obtained in the preceding step is then introduced into an IL flask surmounted by a dropping funnel. The glassware used having been previously pre-dried overnight in a thermostatically controlled oven at 100 ° C. 90 ml of anhydrous dichloromethane are then introduced into the flask followed by 6.92 g (68.4 mmol) of triethylamine. A solution of 5.82 g (55.7 mmol) of methacryloyl chloride (MAC) in 10 mL of anhydrous dichloromethane is introduced into the dropping funnel. The flask is then placed in an ice bath to lower the temperature of the reaction medium to around 0 ° C. The methacryloyl chloride solution is then added dropwise with vigorous stirring. Once the methacryloyl chloride addition is complete, the reaction mixture is left stirring for 1 hour at 0 ° C. and then 17 hours at room temperature. The reaction medium is then transferred to a 500 ml Erlenmeyer flask and 300 ml of dichloromethane are added. The organic phase is then successively washed with 4 × 100 mL of water, 4 × 100 mL of a 0.1 M aqueous hydrochloric acid solution, 4 × 100 mL of a saturated aqueous solution of NaHCO ₃ and new 4 × 100 mL of water. The organic phase is dried over MgSO ₄ , filtered and then concentrated under vacuum using a rotary evaporator to give 11.6 g (89% yield) of protected diol monomer in the form of a light yellow liquid. whose characteristics are as follows:
¹ H NMR (400 MHz, CDCl 3) δ: 7.81 (doublet of doublets, J = 4 Hz and J = 8 Hz, 2H), 7.48 (triplet of triplets, J = 1.2 Hz and J = 7) , 2 Hz, 1H), 7.38 (triplet of triplets, J = 1.2 Hz and J = 6.8 Hz, 1H), 6.10 (singlet, 1H), 5.55 (singlet, 1H) , 4.63-4.53 (multiplet, 1H), 4.44 (doublet of doublets, J = 7.6 Hz and J = 8.8 Hz, 1H), 4.18 (triplet, J = 6.8 Hz, 2H), 3.95 (doublet of doublets, J = 6.8 Hz and J = 8.8 Hz, 1H), 1.94 (doublet of doublets, J = 1.2 Hz and J = 1.6 Hz, 3H), 1.81-1.47 (multiplet, 6H)

1.2.2 Synthesis of methacrylate copolymers according to the invention carrying diol functions

• Copolymérisation de deux monomères méthacrylate d'alkyle avec un monomère méthacrylate porteur d'une fonction diol protégée sous forme d'ester boronique;
• Déprotection du copolymère.

The synthesis of methacrylate copolymers bearing diol functions according to the invention is carried out in two steps (steps 3 and 4 of Scheme 11):

• Copolymerization of two alkyl methacrylate monomers with a methacrylate monomer bearing a protected diol function in the form of a boronic ester;
• Deprotection of the copolymer.

The following procedures describe the synthesis of a poly (alkyl methacrylate-co-alkyldiol methacrylate) copolymer containing about 10 mol%. of monomeric diol units, and having an average length of pendant alkyl chains of 13.8 carbon atoms.

The synthesis of the polymer is carried out according to the following protocol:
13.5 g (40 mmol) of stearyl methacrylate (StMA), 12 g (47.2 mmol) of lauryl methacrylate (LMA), 3.12 g (10.8 mmol) of methacrylate carrying a diol function protected in the form of a boronic ester, 92.1 mg (0.416 mmol) of cumyl dithiobenzoate and 34 ml of anisole are introduced into a 100 ml Schlenk tube. The reaction medium is stirred and 13.7 mg (0.0833 mmol) of azobisisobutyronitrile (AIBN) in solution in 135 .mu.l of anisole are introduced into the Schlenk tube. The reaction medium is then degassed for 30 minutes by bubbling argon before being heated to 65 ° C. for a period of 24 hours. The Schlenk tube is placed in an ice bath to stop the polymerization and 30 mL of tetrahydrofuran (THF) is then added to the reaction medium. The polymer is isolated by precipitation in cold methanol, filtration and drying under vacuum at 30 ° C overnight.

A copolymer having a number average molecular weight ( M _n ) of 70,400 g / mol, a polydispersity index (Ip) of 3,11 and a number-average degree of polymerization (DP _n ) of 228 are thus obtained. These values are respectively obtained by steric exclusion chromatography using tetrahydrofuran as eluent and polystyrene calibration and by monitoring the conversion to monomers during the copolymerization.

The deprotection of the copolymer is carried out according to the following protocol:
19 g of copolymer obtained in the preceding step and containing about 10% of protected diol function are introduced into a 1 L Erlenmeyer flask 250 ml of dichloromethane and 30 ml of an aqueous solution of hydrochloric acid are added. The reaction medium is stirred for 24 hours at ambient temperature before being poured dropwise into 1 L of aqueous sodium hydroxide solution (pH = 10) and then stirred again for 24 hours at room temperature. Throughout this stirring period, the reaction medium is composed of two phases. The organic phase is recovered using a separating funnel and the polymer is precipitated in cold methanol. The polymer thus obtained is redissolved in 100 ml of dichloromethane in order to be precipitated again in cold methanol. The polymer is recovered and dried under vacuum at 30 ° C overnight.

A poly (alkyl methacrylate-co-alkyldiol methacrylate) copolymer containing about 10 mol% of monomer diol units and having an average length of pendant alkyl chains of 13.8 carbon atoms is obtained.

2. Synthesis of the compounds A2 of the invention ∘ 2.1: Synthesis of a boronic diester as crosslinking agent

The synthesis of a compound A2 according to the invention is carried out according to the following protocol and according to the reaction scheme 12:

1,4-Benzenediboronic acid (1,4-BDBA) (1.5 g, 9.05 mmol) is introduced into a 500 mL beaker, followed by 300 mL of acetone. The reaction medium is stirred and 0.300 g (16.7 mmol) of water are introduced dropwise. The reaction medium then becomes transparent and homogeneous and 1,2-dodecanediol (4.02 g, 19.9 mmol) is slowly added. After complete dissolution of the latter, an excess of magnesium sulphate is added in order to trap the water initially introduced as well as the water released by the condensation between 1,4-BDBA and 1,2-dodecanediol. After stirring for 15 minutes, the reaction medium is filtered. The solvent is then removed from the filtrate using a rotary evaporator to give 4.41 g of boronic diester and 1,2-dodecanediol (98% yield) as a white solid.

The characteristics are as follows:
¹ H NMR (400 MHz, CDCl 3) Boronic diester: δ: 7.82 (singlet, 2H), 4.63-4.51 (multiplet, 2H), 4.42 (doublet of doublets, J = 8 Hz and J) = 8.8 Hz, 2H), 3.95 (doublet of doublets, J = 7.2 Hz and J = 8.8 Hz, 2H), 1.81-1.31 (multiplet, 36H), 0.88 (triplet, J = 7.2 Hz, 6H); 1,2-dodecanediol: δ: 3.85-3.25 (multiplet, about 2.17H), 1.81-1.31 (multiplet, about 13.02H), 0.88 (triplet, J = 7, 2 Hz, about 2.17H)

∘ 2.2: Synthesis of the copolymer poly (alkyl methacylate-co-monomer boronic ester) 2.2.1 Synthesis of boronic ester monomer

The boronic ester monomer of the invention is synthesized according to the following reaction scheme 13:

The monomer is obtained according to the protocol in two steps:
The first step is to synthesize a boronic acid and the second step is to obtain a boronic ester monomer.

1 ^st step:

The 4-carboxyphenylboronic acid (CPBA) (5.01 g, 30.2 mmol) is introduced into an IL beaker followed by 350 mL of acetone and the reaction medium is stirred 7.90 mL (439 mmol) ) of water are added dropwise until complete dissolution of 4-carboxyphenylboronic acid. The reaction medium is then transparent and homogeneous. 1,2-Propanediol (2.78 g, 36.6 mmol) is then slowly added, followed by an excess of magnesium sulfate to trap the initially introduced water as well as the water released by the condensation between the CPBA and 1,2 propanediol. The reaction medium is stirred for 1 hour at 25 ° C before being filtered. The solvent is then removed from the filtrate by means of a rotary evaporator. The product thus obtained and 85 ml of DMSO are introduced into a 250 ml flask. The reaction medium is stirred and then after complete homogenization of the reaction medium, 8.33 g (60.3 mmol) of K ₂ CO ₃ are added. 4- (Chloromethyl) styrene (3.34 g, 21.9 mmol) is then slowly introduced into the flask. The reaction medium is then left stirring at 50 ° C. for 16 hours. The reaction medium is transferred to a 2 L Erlenmeyer flask, then 900 ml of water are added. The aqueous phase is extracted with 8 × 150 mL of ethyl acetate. The organic phases are pooled and then extracted with 3 × 250 mL of water. The organic phase is dried over MgSO ₄ and filtered. The solvent was removed from the filtrate using a rotary evaporator to give the boronic acid monomer (5.70 g, 92.2% yield) as a white powder, the characteristics of which are as follows:
¹ H NMR (400 MHz, CDCl 3) δ: 7.98 (doublet, J = 5.6 Hz, 4H), 7.49 (doublet, J = 4 Hz, 4H), 6.77 (doublet of doublets, J = 10.8 Hz and J = 17.6 Hz, 1H), 5.83 (doublet of doublet, J = 1.2 Hz and J = 17.6 Hz, 1H), 5.36 (singlet, 2H), 5.24 (doublet of doublets, J = 1.2 Hz and J = 11.2 Hz, 1H).

2 ^th step:

The boronic acid monomer (5.7 g, 20.2 mmol) obtained in the first step and 500 mL of acetone are introduced into an Erlenmeyer flask. The reaction medium is stirred and 2.6 ml (144 mmol) of water are added dropwise until complete dissolution of the boronic acid monomer. The reaction medium is then transparent and homogeneous. A solution of 1,2-dodecanediol (5.32 g, 26.3 mmol) in 50 mL of acetone is slowly added to the reaction medium, followed by an excess of magnesium sulfate to trap the initially introduced water and as the water released by the condensation between the boronic acid monomer and 1,2-dodecanediol. After stirring for 3 hours at ambient temperature, the reaction medium is filtered. The solvent is then removed from the filtrate by means of a rotary evaporator to give 10.2 g of a mixture of boronic ester monomer and 1,2-dodecanediol in the form of a light yellow solid whose characteristics are as follows: :
¹ H NMR (400 MHz, CDCl 3): Boronic ester monomer: δ: 8.06 (doublet, J = 8 Hz, 2H), 7.89 (doublet, J = 8 Hz, 2H), 7.51 (doublet, J = 4 Hz, 4H), 6.78 (doublet of doublets, J = 8 Hz and J = 16 Hz, 1H), 5.84 (doublet of doublets, J = 1.2 Hz and J = 17.6 Hz , 1H), 5.38 (singlet, 2H), 5.26 (doublet of doublets, J = 1.2 Hz and J = 11.2 Hz, 1H), 4.69-4.60 (multiplet, 1H) , 4.49 (doublet of doublets, J = 8 Hz and J = 9.2 Hz, 1H), 3.99 (doublet of doublets, J = 7.2 Hz and J = 9.2 Hz, 1H), 1 , 78-1.34 (multiplet, 18H), 0.87 (triplet, J = 6.4 Hz, 3H); 1,2-dodecanediol: δ: 3.61-3.30 (multiplet, about 1.62H), 1.78-1.34 (multiplet, about 9.72H), 0.87 (triplet, J = 6, 4 Hz, about 1.62 H).

2.2.2 Synthesis of compound A2, random copolymer poly (alkyl methacrylate-co-monomer boronic ester)

The statistical copolymer A2 of the invention is obtained according to the following protocol:
2.09 g of a boronic ester monomer mixture and 1,2-dodecanediol previously prepared (containing 3.78 mmol of boronic ester monomer), 98.3 mg (0.361 mmol) of cumyl dithiobenzoate, 22.1 g (86.2 g). 9 mmol) of lauryl methacrylate (LMA) and 26.5 ml of anisole are introduced into a 100 ml Schlenk tube. The reaction medium is stirred and 11.9 mg (0.0722 mmol) of azobisisobutyronitrile (AIBN) in solution in 120 .mu.l of anisole are introduced into the Schlenk tube. The reaction medium is then degassed for 30 minutes by bubbling argon before being heated to 65 ° C. for a duration of 16 hours. The Schlenk tube is placed in an ice bath to stop the polymerization, then the polymer is isolated by precipitation in anhydrous acetone, filtration and drying under vacuum at 30 ° C overnight.

avec m =0,96 et n=0,04.
Le copolymère ester boronique obtenu présente une masse molaire moyenne en nombre (M _n) égale à 37 200 g/mol, un indice de polydispersité (Ip) égale à 1,24 et un degré de polymérisation moyen en nombre (DP_n) égal à 166. Ces valeurs sont respectivement obtenues par chromatographie d'exclusion stérique en utilisant le tétrahydrofurane comme éluant et une calibration polystyrène et par suivi de la conversion en monomères au cours de la copolymérisation. Une analyse par RMN du proton du copolymère final donne une composition de 4% molaire en monomère ester boronique et 96 % en méthacrylate de lauryle.A copolymer having the following structure is thus obtained:

with m = 0.96 and n = 0.04.
The boronic ester copolymer obtained has a number-average molecular weight ( M _n ) equal to 37,200 g / mol, a polydispersity index (Ip) equal to 1.24 and a number-average degree of polymerization (DP _n ) equal to 166. These values are respectively obtained by size exclusion chromatography using tetrahydrofuran as eluent and polystyrene calibration and by monitoring the conversion to monomers during the copolymerization. Proton NMR analysis of the final copolymer gives a composition of 4 mol% boronic ester monomer and 96% lauryl methacrylate.

3. Rheological studies Appare 3.1 Apparatuses and protocols for measuring viscosity

The rheological studies were carried out using a Controlled Constraint Couette MCR 501 rheometer from Anton Paar. The measurements were performed on polymer formulations in solution in a Group III base oil using a DG 26.7 cylindrical reference geometry. The viscosity was measured as a function of the shear rate for a temperature range of 10 ° C to 110 ° C. For each temperature, the viscosity of the system was measured as a function of shear rate from 0.01 to 1000 s ^-1 . Viscosity measurements as a function of shear rate at T = 10 ° C, 20 ° C, 30 ° C, 50 ° C, 70 ° C, 90 ° C and 110 ° C were made (ranging from 10 ° C). C at 110 ° C) followed by further measurements at 10 ° C and / or 20 ° C to assess the reversibility of the systems. An average viscosity was then calculated for each temperature using the measuring points located on the same plate.

a été également choisie pour représenter l'évolution de la viscosité du système en fonction de la température, car cette grandeur reflète directement la compensation à la perte de viscosité naturelle de l'huile de base de groupe III des systèmes polymères étudiés.Relative viscosity $\left({\eta }_{\mathit{on}}=\frac{{\eta }_{\mathit{solution}}}{{\eta }_{\mathit{oil}\mathit{of}\mathit{based}}}\right)$

was also chosen to represent the evolution of the viscosity of the system as a function of temperature, since this quantity directly reflects the compensation for the natural viscosity loss of the Group III base oil of the polymer systems studied.

∘ 3.2: Compositions based on random copolymers polydiols A1 and compounds A2 diester boronic. ▪ Compositions tested Copolymers A1:

• ✔ Copolymère A1-1 : Ce copolymère comprend 20% molaire de monomères ayant des fonctions diol. La longueur moyenne de chaînes latérale est de 13,8 atomes de carbone. Sa masse molaire moyenne en nombre est de 49 600 g/mol. Son indice de polydispersité est de 1,51. Son degré de polymérisation moyen en nombre (DP_n) est de 167. La masse molaire moyenne en nombre et l'indice de polydispersité sont mesurés par mesure de chromatographie d'exclusion stérique en utilisant une calibration polystyrène.
• ✔ Copolymère A1-2 : Ce copolymère comprend 20% molaire de monomères ayant des fonctions diol. La longueur moyenne de chaînes latérale est de 10,8 atomes de carbone. Sa masse molaire moyenne en nombre est de 59 700 g/mol. Son indice de polydispersité est de 1,6. Son degré de polymérisation moyen en nombre (DP_n) est de 196. La masse molaire moyenne en nombre et l'indice de polydispersité sont mesurés par mesure de chromatographie d'exclusion stérique en utilisant une calibration polystyrène.
• ✔ Copolymère A1-3 : Ce copolymère comprend 10% molaire de monomères ayant des fonctions diol. La longueur moyenne de chaînes latérale est de 13,8 atomes de carbone. Sa masse molaire moyenne en nombre est de 47 800 g/mol. Son indice de polydispersité est de 1,3. Son degré de polymérisation moyen en nombre (DP_n) est de 198. La masse molaire moyenne en nombre et l'indice de polydispersité sont mesurés par mesure de chromatographie d'exclusion stérique en utilisant une calibration polystyrène.
• ✔ Copolymère A1-4 : Ce copolymère comprend 10% molaire de monomères ayant des fonctions diol. La longueur moyenne de chaînes latérale est de 13,8 atomes de carbone. Sa masse molaire moyenne en nombre est de 97 100 g/mol. Son indice de polydispersité est de 3,11. Son degré de polymérisation moyen en nombre (DP_n) est de 228. La masse molaire moyenne en nombre et l'indice de polydispersité sont mesurés par mesure de chromatographie d'exclusion stérique en utilisant une calibration polystyrène.

Four poly (alkyl methacrylate-co-alkyldiol methacrylate) random copolymers of the invention are tested. These are the following copolymers:

• ✔ Copolymer A1-1: This copolymer comprises 20 mol% of monomers having diol functions. The average side chain length is 13.8 carbon atoms. Its average molar mass is 49,600 g / mol. Its polydispersity index is 1.51. Its number-average degree of polymerization (DP _n ) is 167. The number average molecular weight and the polydispersity index are measured by steric exclusion chromatography using a polystyrene calibration.
• ✔ Copolymer A1-2: This copolymer comprises 20 mol% of monomers having diol functions. The average side chain length is 10.8 carbon atoms. Its average molecular weight is 59 700 g / mol. Its polydispersity index is 1.6. Its number-average degree of polymerization (DP _n ) is 196. The number average molecular weight and the polydispersity index are measured by steric exclusion chromatography using a polystyrene calibration.
• ✔ Copolymer A1-3: This copolymer comprises 10 mol% of monomers having diol functions. The average side chain length is 13.8 carbon atoms. Its average molar mass is 47,800 g / mol. Its polydispersity index is 1.3. Its number-average degree of polymerization (DP _n ) is 198. The number average molecular weight and the polydispersity index are measured by steric exclusion chromatography using a polystyrene calibration.
• ✔ Copolymer A1-4: This copolymer comprises 10 mol% of monomers having diol functions. The average side chain length is 13.8 carbon atoms. Its average molar mass is 97 100 g / mol. Its polydispersity index is 3.11. Its number-average degree of polymerization (DP _n ) is 228. The number-average molar mass and the polydispersity index are measured by steric exclusion chromatography using a polystyrene calibration.

The copolymers A1-1, A1-2, A1-3 and A1-4 are obtained according to one of the protocols described in paragraph 1.

Compound A2 :

Compound A2-1 is the boronic diester obtained according to the protocol described in section 2.1.

Lubricating base oil

• sa viscosité cinématique à 40°C mesurée selon la norme ASTM D445 est de 19,57 cSt ;
• sa viscosité cinématique mesurée à 100°C selon la norme ASTM D445 est de 4,23 cSt ;
• son indice de viscosité mesuré selon la norme ASTM D2270 est de 122 ;
• sa volatilité Noack en pourcentage poids, mesurée selon la norme DIN 51581 est de 14, 5 ;
• Son point flash (flash point en anglais) en degrés Celsius mesuré selon la norme ASTM D92 est de 230°C;
• Son point d'écoulement (pour point en anglais) en degrés Celsius mesuré selon la norme ASTM D97 est de -15°C.

The lubricating base oil used in the compositions to be tested is a Group III API oil sold by SK under the name Yubase 4. It has the following characteristics:

• its kinematic viscosity at 40 ° C measured according to ASTM D445 is 19.57 cSt;
• its kinematic viscosity measured at 100 ° C according to ASTM D445 is 4.23 cSt;
• its viscosity number measured according to ASTM D2270 is 122;
• its Noack volatility in weight percent, measured according to DIN 51581 is 14.5;
• Its flash point in degrees Celsius measured according to ASTM D92 is 230 ° C;
• Its pour point (for point in English) in degrees Celsius measured according to the ASTM D97 standard is -15 ° C.

Composition A (outside the invention) is used as a reference.

It contains a 4.2% by weight solution of a polymethacrylate polymer in API Group III lubricating base oil. The polymer has a number average molecular weight ( M _n ) equal to 106,000 g / mol, a polydispersity index (Ip) of 3.06, a number average polymerization degree of 466 and the average length of the pendant chains is 14 carbon atoms.

This polymethacrylate is used as a viscosity index improving additive.

4.95 g of a formulation having a mass concentration of 42% of this polymethacrylate in a Group III base oil and 44.6 g of Group III base oil are introduced into a flask. The solution thus obtained is stirred at 90 ° C. until the polymethacrylate is completely dissolved.

A 4.2% by weight solution of this polymethacrylate is obtained.

Composition B-1 (except the invention) is obtained as follows:

4.14 g of polydiol copolymer A1-1 and 37.2 g of base oil group III are introduced into a flask. The solution thus obtained is stirred at 90 ° C. until the polydiol is completely dissolved.

A 10% by weight solution of polydiol copolymer A1-1 is obtained.

Composition C-1 (according to the invention) is obtained as follows:

8 g of the 10% by weight solution of polydiol copolymer A1-1 in the Group III base oil previously prepared are introduced into a flask. 55.8 mg of boronic diester A2-1 are added to this solution. The solution thus obtained is stirred at 90 ° C. until complete dissolution of the boronic diester.

A 10% by weight solution of polydiol copolymer A1-1 and 20 mol% of boronic diester A2-1 is obtained relative to the diol functions of the polydiol copolymer A1-1.

Composition D-1 (according to the invention) is obtained as follows:

8 g of the 10% by weight solution of polydiol copolymer A1-1 in the Group III base oil previously prepared are introduced into a flask. 223 mg of boronic diester A2-1 are added to this solution. The solution thus obtained is stirred at 90 ° C. until complete dissolution of the boronic diester.

A 10% by weight solution of polydiol copolymer A1-1 and 80 mol% of boronic diester A2-1 is obtained relative to the diol functions of the polydiol copolymer A1-1.

Composition B-2 (except the invention) is obtained as follows:

6.52 g of polydiol copolymer A1-2 and 58.7 g of base oil group III are introduced into a flask. The solution thus obtained is stirred at 90 ° C. until the polydiol is completely dissolved.

A 10% by weight solution of polydiol copolymer A1-2 is obtained.

Composition C-2 (according to the invention) is obtained as follows:

8 g of the 10% by weight solution of polydiol copolymer A1-2 in the Group III base oil previously prepared are introduced into a flask. 65.4 mg of boronic diester A2-1 are added to this solution. The solution thus obtained is stirred at 90 ° C. until complete dissolution of the boronic diester.

A 10% by weight solution of polydiol copolymer A1-2 and 20 mol% of boronic diester A2-1 is obtained relative to the diol functions of the polydiol copolymer A1-2.

Composition D-2 (according to the invention) is obtained as follows:

8 g of the 10% by weight solution of polydiol copolymer A1-2 in the Group III base oil previously prepared are introduced into a flask. 262 mg of boronic diester A2-1 are added to this solution. The solution thus obtained is stirred at 90 ° C. until complete dissolution of the boronic diester.

A 10% by weight solution of polydiol copolymer A1-2 and 80 mol% of boronic diester A2-1 is obtained relative to the diol functions of the polydiol copolymer A1-2.

Composition B-3 (except the invention) is obtained as follows:

7.24 g of polydiol copolymer A1-3 and 65.2 g of base oil group III are introduced into a flask. The solution thus obtained is stirred at 90 ° C. until the polydiol is completely dissolved.

A 10% by weight solution of polydiol copolymer A1-3 is obtained.

Composition C-3 (according to the invention) is obtained in the following manner:

8 g of the 10% by weight solution of polydiol copolymer A1-3 in the Group III base oil previously prepared are introduced into a flask. 28.2 mg of boronic diester A2-1 are added to this solution. The solution thus obtained is stirred at 90 ° C. until complete dissolution of the boronic diester.

A 10% by weight solution of polydiol copolymer A1-3 and 20 mol% of boronic diester A2-1 is obtained relative to the diol functions of the polydiol copolymer A1-3.

Composition B-4 (except the invention) is obtained as follows:

4.99 g of polydiol copolymer A1-4 and 44.4 g of base oil group III are introduced into a flask. The solution thus obtained is stirred at 90 ° C. until the polydiol is completely dissolved.

A 10% by weight solution of polydiol copolymer A1-4 is obtained.

Composition C-4 (according to the invention) is obtained as follows:

6.01 g of the 10% by weight solution of polydiol copolymer A1-4 in the Group III base oil previously prepared are introduced into a flask. 18.6 mg of boronic diester A2-1 are added to this solution. The solution thus obtained is stirred at 90 ° C. until complete dissolution of the boronic diester.

A 10% by weight solution of polydiol copolymer A1-4 and 20 mol% of boronic diester A2-1 is obtained relative to the diol functions of the polydiol copolymer A1-4.

Composition D-4 (according to the invention) is obtained as follows:

6.03 g of the 10% by weight solution of polydiol copolymer A1-4 in the Group III base oil previously prepared are introduced into a flask. 74.7 mg of boronic diester A2-1 are added to this solution. The solution thus obtained is stirred at 90 ° C. until complete dissolution of the boronic diester.

A 10% by weight solution of polydiol copolymer A1-4 and 80 mol% of boronic diester A2-1 is obtained relative to the diol functions of the polydiol copolymer A1-4.

▪ Results obtained in rheology

The rheological behavior of the composition C1-1 was studied for a temperature range from 10 ° C to 110 ° C. The results are presented in figure 5 . The dynamic viscosity of composition C1-1 varies at low shear rates and at temperatures below 50 ° C. Composition C1-1 is deformed under shear stress for temperatures below 50 ° C.

For temperatures above 50 ° C., the dynamic viscosity of composition C1-1 varies very slightly or does not vary at low shear rates. The composition C1-1 is no longer deformed under the shear stress at these temperatures.

The relative viscosity of compositions A, B-1, C-1, D-1, B-2, C-2, D-2, B-3, C-3, D-3, B-4, C-4 , D-4 has been studied. The evolution of the relative viscosity of these compositions is illustrated in Figures 6A-6D . By comparing the results obtained, it is observed that certain parameters influence the relative viscosity of the compositions.

❖ The influence of L _C (average length of pendant side chain)

The polydiols copolymers A1-1 and A1-2 have the same percentage of diol monomer (M1) per chain, comparable molar masses, but an average length of the alkyl chains of the different monomers (L _C = 13.8 and L _C = 10 , 8 respectively).

The evolution of the relative viscosity as a function of temperature for the solutions formulated from these polymers ( Figure 6A and 6B ) indicates that the average length of the alkyl chains of the monomers constituting the polydiol copolymer plays a role in the rheological properties of the formulations.

❖ The influence of the molar percentage of diol monomer (% diol)

The polydiols copolymers A1-1 and A1-3 have the same average length of the alkyl chains (L _C ), comparable molar masses but a percentage of diol monomer (M1) per skeletal chain different (20% and 10% respectively).

The evolution of the relative viscosity as a function of temperature for the solutions formulated from these polymers ( Figure 6A and 6C ) indicates that the percentage of diol monomer per skeletal chain plays a role in the rheological properties of the formulations.

❖ The influence of molar masses (DP _n )

The polydiols A1-3 and A1-4 have the same percentage of diol monomer (M1) per chain, the same average length of the alkyl chains (L _C ) but substantially different molar masses (47,800 g / mol and 97,100 g / mol). mol respectively) and degrees of substantially different number average polymerization (DP _n 198 and 228 respectively).

The evolution of the relative viscosity as a function of temperature for the solutions formulated from these polymers ( Figure 6.C and 6.D ) indicates that the molar mass of the polydiol copolymers (Mn) plays a role in the rheological properties of the formulations.

3.2: Compositions based on random copolymers polydiols A1 and compounds A2 polymer boronic ester. ▪ Compositions tested Copolymers A1:

A random poly (alkyl methacrylate-co-alkyldiol methacrylate) copolymer of the invention is tested. It is the following copolymer:
✔ Copolymer A1-1: This copolymer comprises 20 mol% of monomers having diol functions. The average side chain length is 13.8 carbon atoms. Its average molar mass is 49,600 g / mol. Its polydispersity index is 1.51. Its number-average degree of polymerization (DP _n ) is 167. The number average molecular weight and the polydispersity index are measured by steric exclusion chromatography using a polystyrene calibration.

The copolymer A1-1 is obtained according to one of the protocols described in paragraph 1.

Compound A2:

Compound A2-2 is the boronic ester polymer obtained according to the protocol described in section 2.2. This copolymer comprises 4 mol% of monomers having boronic ester functions. The average side chain length is greater than 12 carbon atoms. Its average molar mass is 37,200g / mol. Its polydispersity index is 1.24. Its number-average degree of polymerization (DP _n ) is 166. The number average molecular weight and the polydispersity index are measured by steric exclusion chromatography using a polystyrene calibration.

Lubricating base oil

The lubricating base oil used in the compositions to be tested is the group III oil described above in section 3.1.

Composition A (outside the invention) is used as a reference and is the same as Composition A used in Section 3.1.

Composition B (except the invention) is obtained as follows:

Composition B is the same composition B-1 used in section 3.1.

Composition C (according to the invention) is obtained as follows:

4 g of the 10% by weight solution of polydiol copolymer A1-1 in the Group III base oil previously prepared are introduced into a flask. 76.8 mg of boronic ester polymer A2-2 and 4 g of the base oil group III are added to this solution. The solution thus obtained is stirred at 90 ° C. until the boronic ester polymer is completely dissolved.

A 5% by weight solution of polydiol copolymer A1-1 and 1% by weight of boron ester polymer A2-2 is obtained relative to the total mass of the composition.

Composition D (according to the invention) is obtained in the following manner:

6 g of the solution of the preceding composition C (that is to say the composition at 5% by weight of polydiol copolymer A1-1 and 1% by weight of boron ester polymer A2-2 relative to the total mass of the composition ) are introduced into a bottle. 61.9 mg of boron ester polymer A2-2 are added to this solution. The solution thus obtained is stirred at 90 ° C. until the boronic ester polymer is completely dissolved.

A 5% by weight solution of polydiol copolymer A1-1 and 2% by weight of boron ester polymer A2-2 is obtained relative to the total mass of the composition.

Composition E (according to the invention) is obtained as follows:

3 g of the 10% by weight solution of polydiol copolymer A1-1 in the Group III base oil previously prepared are introduced into a flask. 176 mg of A2-2 boronic ester polymer and 3 g of the Group III base oil are added to this solution. The solution thus obtained is stirred at 90 ° C. until the boronic ester polymer is completely dissolved.

A 5% by weight solution of polydiol copolymer A1-1 and 3% by weight of boron ester polymer A2-2 is obtained relative to the total mass of the composition.

▪ Results obtained in rheology

The rheological behavior of the composition E was studied for a temperature range from 10 ° C to 110 ° C. The results are presented in figure 7 . The dynamic viscosity of composition E varies at low shear rates and at temperatures below 50 ° C. Composition E deforms under shear stress for temperatures below 50 ° C.

For temperatures above 50 ° C., the dynamic viscosity of the composition E varies very slightly or does not vary at low shear rates. Composition E does not no longer deforms under shear stress at these temperatures.

The relative viscosity of compositions A, B, C, D and E was studied. The evolution of the relative viscosity of these compositions is illustrated in figure 8 . This figure indicates that the polydiols / poly (boronic ester) systems can very significantly offset the natural viscosity drop of the base oil as a function of temperature. In addition, the effect obtained can be regulated by varying the mass concentrations of the various polymers in solution in the base oil III.

Composition F (outside the invention) is obtained as follows:

A VI booster polymer (Viscoplex V6.850 sold by Rohmax) is added to the lubricating base oil described above.

Viscoplex 6.850 comprises 41.8% active ingredient of a linear polymethacrylate.

The composition thus obtained has the following characteristics; the percentages indicated correspond to percentages by weight relative to the total weight of the composition F: % Lubricating base oil 80.86 Viscoplex V6.850 19.14 (corresponding to 8% active ingredient of polymethacrylate)

The kinematic viscosities at 40 ° C and 100 ° C are measured for compositions E and F according to ASTM D445 and the VI (viscosity index) is calculated for these two compositions; the results are shown in Table I below. Table I Composition E Composition F KV 40 (mm ² / s) 48.16 98.17 KV 100 (mm ² / s) 21.417 23.82 VI 450 274 These results show that the lubricant compositions according to the invention show a marked increase in VI compared with a lubricating composition comprising a conventional VI booster polymer.
It should be noted that this increase in VI is demonstrated without increasing the polymer content in the lubricating composition.

Claims (15)

1. Composition resulting from the mixing of:

   • at least one lubricating oil,

   • at least one random copolymer A1 and at least one compound A2 comprising at least two boronic ester functional groups, it being possible for the compound A2 to join together and establish covalent chemical bonds of boronic ester type with the random copolymer A1 in a thermally reversible manner;
   ∘ the random copolymer A1 resulting from the copolymerization:

   ▪ of at least one first monomer M1 of general formula (I):

   

   in which:

   - R₁ is chosen from the group formed by -H, -CH₃ and -CH₂-CH₃;

   - x is an integer ranging from 2 to 18;

   - y is an integer equal to 0 or 1;

   - X₁ and X₂, which are identical or different, are chosen from the group formed by hydrogen, tetrahydropyranyl, methyloxymethyl, tert-butyl, benzyl, trimethylsilyl and t-butyldimethylsilyl;

   or else

   - X₁ and X₂ form, with the oxygen atoms, a bridge of following formula:

   

   in which:

   - the stars (*) symbolise the bonds to the oxygen atoms,

   - R'₂ and R"₂, which are identical or different, are chosen from the group formed by hydrogen and C₁-C₁₁ alkyl, preferably methyl;
   or else

   - X₁ and X₂ form, with the oxygen atoms, a boronic ester of following formula:

   

   in which:

   - the stars (*) symbolise the bonds to the oxygen atoms,

   - R'"₂ is chosen from the group formed by a C₆-C₁₈ aryl, a C₇-C₁₈ arylalkyl and C₂-C₁₈ alkyl, preferably a C₆-C₁₈ aryl;

   ▪ with at least one second monomer M2 of general formula (II-A):

   

   in which:

   - R₂ is chosen from the group formed by -H, -CH₃ and -CH₂-CH₃,

   - R₃₁ is chosen from the group formed by a C₆-C₁₈ aryl, a C₆-C₁₈ aryl substituted by a group of type R'₃, -C(O)-O-R'₃, -O-R'₃, -S-R'₃ and -C(O)-N(H)-R'₃, with R'₃ a C₁-C₃₀ alkyl group.
2. Composition according to Claim 1, in which the random copolymer A1 results from the copolymerization of at least one monomer M1 with at least two monomers M2 having different R₃₁ groups.
3. Composition according to Claim 2, in which one of the monomers M2 of the random copolymer A1 has the general formula (II-A1):

   

   in which:

   - R₂ is chosen from the group formed by -H, -CH₃ and -CH₂-CH₃,

   - R"₃₁ is a C₁-C₁₄ alkyl group,

   and the other monomer M2 of the random copolymer A1 has the general formula (II-A2):

   

   in which:

   - R₂ is chosen from the group formed by -H, -CH₃ and -CH₂-CH₃,

   - R"'₃₁ is a C₁₅-C₃₀ alkyl group.
4. Composition according to any one of Claims 1 to 3, in which the compound A2 is a compound of formula (III):

   

   in which:

   - W₁ and W₂, which are identical or different, are integers chosen between 0 and 1,

   - R₄, R₅, R₆ and R₇, which are identical or different, are chosen from the group formed by hydrogen and a hydrocarbon group having 1 to 24 carbon atoms, preferably between 4 and 18 carbon atoms, preferably between 6 and 14 carbon atoms;

   - L is a divalent bonding group and is chosen from the group formed by a C₆-C₁₈ aryl, a C₆-C₁₈ aralkyl and a C₂-C₂₄ hydrocarbon chain.
5. Composition according to any one of Claims 1 to 3, in which the compound A2 is a random copolymer resulting from the copolymerization:

   ▪ of at least one monomer M3 of formula (IV):

   

   in which:

   - t is an integer equal to 0 or 1;

   - u is an integer equal to 0 or 1;

   - M and R₈ are identical or different divalent bonding groups and are chosen from the group formed by a C₆-C₁₈ aryl, a C₇-C₂₄ aralkyl and C₂-C₂₄ alkyl, preferably a C₆-C₁₈ aryl,

   - X is a functional group chosen from the group formed by -O-C(O)-, -C(O)-O-, -C(O)-N(H)-, -N(H)-C(O)-, -S-, -N(H)-, -N( R'₄)- and -O- with R'₄ a hydrocarbon chain comprising from 1 to 15 carbon atoms;

   - Rg is chosen from the group formed by -H, -CH₃ and -CH₂-CH₃;

   - R₁₀ and R₁₁, which are identical or different, are chosen from the group formed by hydrogen and a hydrocarbon group having 1 to 24 carbon atoms, preferably between 4 and 18 carbon atoms, preferably between 6 and 14 carbon atoms,

   ▪ with at least one second monomer M4 of general formula (V):

   

   in which:

   - R₁₂ is chosen from the group formed by -H, -CH₃ and -CH₂-CH₃,

   - R₁₃ is chosen from the group formed by a C₆-C₁₈ aryl, a C₆-C₁₈ aryl substituted by a group of type R'₁₃, -C(O)-O-R'₁₃, -O-R'₁₃, -S-R'₁₃ and -C(O)-N(H)-R'₁₃, with R'₁₃ a C₁-C₂₅ alkyl group.
6. Composition according to Claim 5, in which the chain formed by the linking together of the R₁₀, M, X and (R₈)_u groups with u equal to 0 or 1 of the monomer of general formula (IV) exhibits a total number of carbon atoms of between 8 and 38, preferably between 10 and 26.
7. Composition according to either of Claims 5 and 6, in which the side chains of the copolymer A2 have a mean length of greater than 8 carbon atoms, preferably between 11 and 16 carbon atoms.
8. Composition according to one of Claims 5 to 7, in which the random copolymer A2 has a molar percentage of monomer of formula (IV) in the said copolymer ranging from 0.25% to 20%, preferably from 1 to 10%, and/or a number-average degree of polymerization ranging from 50 to 1500, preferably from 80 to 800.
9. Composition according to one of Claims 1 to 8, in which the side chains of the random copolymer A1 have a mean length ranging from 8 to 20 carbon atoms, preferably from 9 to 15 carbon atoms.
10. Composition according to one of Claims 1 to 9, in which the random copolymer A1 has a molar percentage of monomer M1 of formula (I) ranging, in the said copolymer, from 1% to 30%, preferably ranging from 5% to 25%, more preferably ranging from 9% to 21%, and/or an average degree of polymerization ranging from 100 to 2000, preferably from 150 to 1000.
11. Composition according to any one of Claims 1 to 10, in which the lubricating oil is chosen from the oils of Group I, of Group II, of Group III, of Group IV or of Group V of the API classification and one of their mixtures.
12. Composition according to one of Claims 1 to 11, additionally comprising a functional additive chosen from the group formed by detergents, anti-wear additives, extreme pressure additives, additional antioxidants, polymers which improve the viscosity number, pour point improvers, antifoaming agents, corrosion inhibitors, thickeners, dispersants, friction modifiers and their mixtures.
13. Composition according to one of Claims 1 to 12, in which the ratio weight of the random copolymer A1 to the compound A2 (A1/A2 ratio) ranges from 0.001 to 100, preferably from 0.05 to 20, more preferably still from 0.01 to 10 and more preferably still from 0.2 to 5 or in which the sum of the weights of the random copolymer A1 and of the compound A2 ranges from 0.5% to 20%, with respect to the total weight of the lubricating composition, and the weight of lubricating oil ranges from 80% to 99.5%, with respect to the total weight of the lubricating composition.
14. Use of a composition according to one of Claims 1 to 13 for lubricating a mechanical part.
15. Mother composition resulting from the mixing of:

    • at least one random copolymer A1;

    • at least one compound A2 comprising at least two boronic ester functional groups, it being possible for the compound A2 to join together and establish covalent chemical bonds of boronic ester type with the random copolymer A1 in a thermally reversible manner; and

    • at least one functional additive chosen from the group formed by detergents, anti-wear additives, extreme pressure additives, antioxidants, polymers which improve the viscosity number, pour point improvers, antifoaming agents, thickeners, dispersants, friction modifiers and their mixtures;
    ∘ the random copolymer A1 resulting from the copolymerization:

    ▪ of at least one first monomer M1 of general formula (I):

    

    in which:

    - R₁ is chosen from the group formed by -H, -CH₃ and -CH₂-CH₃;

    - x is an integer ranging from 2 to 18;

    - y is an integer equal to 0 or 1;

    - X₁ and X₂, which are identical or different, are chosen from the group formed by hydrogen, tetrahydropyranyl, methyloxymethyl, tert-butyl, benzyl, trimethylsilyl and t-butyldimethylsilyl;
    or else

    - X₁ and X₂ form, with the oxygen atoms, a bridge of following formula:

    

    in which:

    - the stars (*) symbolise the bonds to the oxygen atoms,

    - R'₂ and R"₂, which are identical or different, are chosen from the group formed by hydrogen and C₁-C₁₁ alkyl, preferably methyl;

    or else

    - X₁ and X₂ form, with the oxygen atoms, a boronic ester of following formula:

    

    in which:

    - the stars (*) symbolise the bonds to the oxygen atoms,

    - R'"₂ is chosen from the group formed by a C₆-C₁₈ aryl, a C₇-C₁₈ arylalkyl and C₂-C₁₈ alkyl, preferably a C₆-C₁₈ aryl;

    ▪ with at least one second monomer M2 of general formula (II-A):

    

    in which:

    - R₂ is chosen from the group formed by -H, -CH₃ and -CH₂-CH₃,

    - R₃₁ is chosen from the group formed by a C₆-C₁₈ aryl, a C₆-C₁₈ aryl substituted by a group of type R'₃, -C(O)-O-R'₃, -O-R'₃, -S-R'₃ and -C(O)-N(H)-R'₃, with R'₃ a C₁-C₃₀ alkyl group.

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