Synthesis method of polyethylene or copolymer of ethylene and 1, 3-diene with terminal ketone functional group

Abstract

The present invention relates to a process for the preparation of polyethylene or copolymers of ethylene with 1, 3-dienes and optionally vinyl aromatic compounds having terminal ketone functions, said copolymers containing more than 50 mol% ethylene and having terminal ketone functions; the method comprises the following steps: carrying out a polymerization reaction on monomers in the presence of a cyclopentadienyl neodymium borohydride complex and an organic magnesium compound, then carrying out a coupling reaction with a compound with a nitrile functional group, and then carrying out a hydrolysis reaction.

Description

Technical Field

[0001] The field of the invention is that of polyethylenes and copolymers of ethylene with α-olefins which are rich in ethylene units and functionalized at the chain ends by polar functional groups (ketones). Background Art

[0002] The synthesis of polyethylene and alpha-olefin copolymers is widely described in the scientific literature. It is well known that the choice of polymerization route will determine the structure of the polymer chain. As described in WO 2014 / 114607 A1, the polymerization of coordination catalysis by using certain neodymium metallocenes can produce polyethylene and diene copolymers rich in ethylene units (containing more than 50 mol % of ethylene units). In particular, copolymers containing ethylene units and diene units are synthesized by a polymerization mechanism involving highly specific reactants and a large number of transfer reactions, as described in ACS Catalysis (2016, Vol. 6, No. 2, pp. 1028-1036).

[0003] Highly saturated polymers (such as polyethylene and diene copolymers rich in ethylene units) are essentially hydrocarbons and have little affinity for polar substances, which results in limiting the application areas of these highly saturated hydrocarbon polymers. In order to improve this affinity, in the case of polyethylene, the introduction of one or more ketone functional groups has been described. For example, the synthesis of copolymers of ethylene and carbon monoxide has been widely described, but the synthesis method is not applicable to copolymers of ethylene and α-olefins (such as 1,3-dienes or mixtures of 1,3-dienes and vinyl aromatic compounds). In addition, the synthesis method does not selectively cause the introduction of chain-end ketone functional groups. The introduction of a single ketone functional group at the chain end of polyethylene is also described. For example, Polymer Science (Ser. B, Vol. 46, No. 9-10, 2004, 308-311) describes the reaction between nitrous oxide and polyethylene with vinyl groups at the chain end. The oxidation reaction of the double bond of the vinyl group with nitrous oxide introduces a ketone functional group at the chain end of polyethylene. It can be seen from this that this synthesis method is not suitable for the selective functionalization of the chain ends of the following copolymers of ethylene and 1,3-diene: copolymers that also contain double bonds outside the chain ends.

[0004] Finally, the described methods for introducing the keto function do not allow the simultaneous introduction of a second functional group other than the keto function, and for this they must resort to the use of additional functionalizing agents. Summary of the invention

[0005] The applicant has developed a method that allows the introduction of ketone functional groups at the ends of polymer chains, which method is applicable to both polyethylene and diene copolymers rich in ethylene units, such as copolymers of ethylene with 1,3-diene, or even copolymers of ethylene, 1,3-diene and vinyl aromatic compounds. In addition, the method is also suitable for the simultaneous introduction of two functional groups, namely a ketone functional group and a second functional group other than the ketone functional group, without the need to resort to additional functionalizing agents.

[0006] A first subject of the invention is a process for preparing polymers containing more than 50 mol % of ethylene units and carrying a keto function at one of their chain ends,

[0007] The method comprises the consecutive steps a), b) and c):

[0008] - step a) consists in polymerizing a monomer mixture containing ethylene in the presence of a catalytic system based on at least one metallocene of formula (I) and an organomagnesium reagent,

[0009] {P(Cp 1 )(Cp 2 )Nd(BH4) (1+y)- L y -N x} (I)

[0010] Cp 1 and Cp 2 are the same or different and are selected from fluorenyl, cyclopentadienyl and indenyl, which groups are substituted or unsubstituted,

[0011] P is the bridge Cp 1 and Cp 2 Two groups and groups containing silicon atoms or carbon atoms,

[0012] Nd represents a neodymium atom,

[0013] L represents an alkali metal selected from lithium, sodium and potassium,

[0014] N represents an ether molecule,

[0015] x can be an integer or non-integer greater than or equal to 0.

[0016] y is an integer greater than or equal to 0,

[0017] - step b) is to react a compound containing a nitrile functional group with the product of the polymerization reaction in step a),

[0018] - Step c) is a hydrolysis reaction,

[0019] The polymer is polyethylene or a copolymer of ethylene with a 1,3-diene and optionally a vinyl aromatic compound.

[0020] A second subject of the invention is a polymer containing more than 50 mol % of ethylene units and carrying at one of its chain ends a keto function and optionally a second functional group, carried at the same chain end as the keto function and chosen from ether, thioether, amine, alkoxysilane, silanol and imidazole functions, said polymer being a copolymer of ethylene with a 1,3-diene or a copolymer of ethylene, a 1,3-diene and a vinyl aromatic compound and obtainable by a particular embodiment of the process according to the invention.

[0021] A third subject of the invention is a polyethylene carrying at one of its chain ends a keto function and a second functional group, the second functional group being carried at the same chain end as the keto function and being chosen from ether, thioether, amine, alkoxysilane, silanol and imidazole functional groups, obtainable by a particular embodiment of the process according to the invention.

[0022] illustrate

[0023] Any numerical interval represented by the expression "between a and b" means a numerical range greater than "a" and less than "b" (i.e., excluding the end values ​​a and b), while any numerical interval represented by the expression "a to b" means a numerical range extending from "a" to "b" (i.e., including the strict end values ​​a and b).

[0024] Unless otherwise specified, the content of the unit resulting from the insertion of a monomer into a copolymer is expressed as a mole percentage relative to all units resulting from the polymerization of the monomer.

[0025] The compounds mentioned in this specification may be compounds of fossil origin or may be bio-based compounds. In the case where the compounds are bio-based compounds, they may be partially or completely derived from biomass or may be obtained by renewable raw materials derived from biomass. Similarly, the compounds mentioned may also be derived from the recycling of already used materials, i.e. they may be partially or completely produced by a recycling process or may be obtained by raw materials that themselves are produced from a recycling process.

[0026] The term "based on" used to define the components of the catalytic system means a mixture of these components, or a product of the reaction of some or all of these components with one another.

[0027] Step a) of the process according to the invention is the polymerization of a monomer mixture containing ethylene, which allows the preparation of growing polymer chains intended to react with a functionalizing agent (compound containing a nitrile function) in the next step (step b)).

[0028] According to a first alternative, the monomer mixture containing ethylene is ethylene, i.e. a monomer mixture consisting only of ethylene. According to this alternative, the product of the polymerization reaction in step a) is a polymer chain whose constituent units result from the insertion of ethylene. The polymer prepared by this alternative is an ethylene homopolymer, i.e. a polyethylene.

[0029] According to a second alternative, the monomer mixture containing ethylene is a mixture of ethylene and 1,3-diene. According to this alternative, the reaction product of the polymerization in step a) is a polymer chain whose constituent units result from the insertion of ethylene and 1,3-diene. The polymer prepared by this second alternative is a copolymer of ethylene and 1,3-diene.

[0030] According to a third alternative of the invention, the monomer mixture containing ethylene is a mixture of ethylene, 1,3-diene and vinyl aromatic compounds. According to this alternative, the reaction product of the polymerization in step a) is a polymer chain whose constituent units result from the insertion of ethylene, 1,3-diene and vinyl aromatic compounds. The polymer prepared by this third alternative is a copolymer of ethylene, 1,3-diene and vinyl aromatic compounds.

[0031] The 1,3-dienes of the monomer mixture in step a) for the purposes of the second alternative and the third alternative are either single compounds, i.e. single 1,3-dienes, or mixtures of 1,3-dienes which differ from one another in chemical structure. Suitable 1,3-dienes for use are 1,3-dienes containing 4 to 20 carbon atoms, such as 1,3-butadiene, isoprene, myrcene and β-farnesene, and mixtures thereof. The 1,3-dienes are preferably 1,3-butadiene, isoprene, myrcene, β-farnesene or mixtures thereof, in particular mixtures of at least two thereof.

[0032] The vinyl aromatic compound of the monomer mixture in step a) for the purpose of the third alternative is a single compound, i.e. a single vinyl aromatic compound, or a mixture of vinyl aromatic compounds having chemical structures different from each other. The term "vinyl aromatic compound" means an aromatic compound substituted by a vinyl functional group having the well-known formula (-CH=CH2). The most particularly suitable vinyl aromatic compounds are compounds containing an aromatic group substituted by a vinyl functional group, more particularly compounds containing a phenyl group substituted by a vinyl functional group. The vinyl aromatic compound is preferably styrene or styrene in which the benzene ring is substituted by an alkyl group. The vinyl aromatic compound is more preferably styrene. The copolymer prepared by the preferred embodiment of the third alternative is a copolymer of ethylene, 1,3-diene and styrene.

[0033] Preferably, the monomer mixture in step a) contains more than 50 mol % of ethylene, this percentage being expressed relative to the total number of moles of the monomers of the monomer mixture in step a). When the monomer mixture contains a vinyl aromatic compound such as styrene, it preferably contains less than 40 mol % of vinyl aromatic compound, this percentage being expressed relative to the total number of moles of the monomers of the monomer mixture in step a).

[0034] The polymerization of the monomer mixture can be carried out according to patent applications WO 2007 / 054223 A2 and WO 2007 / 054224 A2 using a catalytic system (or catalytic composition) consisting of a metallocene and an organomagnesium reagent.

[0035] In the present patent application, the term "metallocene" means an organometallic complex whose metal (in appropriate cases a neodymium atom) is bound to a Cp bond called a ligand and which is linked together by bridges P. 1 and Cp 2 These Cp 1 and Cp 2 The groups are identical or different and are selected from fluorenyl, cyclopentadienyl and indenyl, and these groups may be substituted or unsubstituted.

[0036] According to the present invention, the metallocene used as an essential component in the catalytic system corresponds to the formula (Ia)

[0037] {P(Cp 1 )(Cp 2 )Nd(BH4) (1+y)- L y -N x} (I)

[0038] P is the bridge Cp 1 and Cp 2 Two groups and groups containing silicon atoms or carbon atoms,

[0039] Cp 1 and Cp 2 are the same or different and are selected from fluorenyl, cyclopentadienyl and indenyl, which groups are substituted or unsubstituted,

[0040] Nd represents a neodymium atom,

[0041] L represents an alkali metal selected from lithium, sodium and potassium,

[0042] N represents an ether molecule,

[0043] x can be an integer or non-integer greater than or equal to 0.

[0044] y is an integer greater than or equal to 0.

[0045] In formula (I), the neodymium atom is connected to a Cp bonded together by a bridge P. 1 and Cp 2 Preferably, the symbol P represented by the term bridge corresponds to the formula ZR 1 R 2 , Z represents a silicon atom or a carbon atom, R 1 and R 2 are the same or different and represent an alkyl group containing 1 to 20 carbon atoms. More preferably, the bridge P is of the formula SiR 1 R 2 , R 1 and R 2 The same and as defined above. Still more preferably, P corresponds to the formula SiMe2.

[0046] In formula (I), any ether capable of complexing an alkali metal (especially diethyl ether, methyltetrahydrofuran and tetrahydrofuran, preferably tetrahydrofuran) is suitable as the ether.

[0047] As substituted cyclopentadienyl, fluorenyl and indenyl, mention may be made of those substituted by an alkyl group containing 1 to 6 carbon atoms or an aryl group containing 6 to 12 carbon atoms or a trialkylsilyl group such as SiMe3. 1 and Cp 2 When substituted, they are preferably substituted by methyl, butyl (especially tert-butyl) or trimethylsilyl. The choice of the radical also depends on the availability of the corresponding molecules, which are substituted cyclopentadienes, fluorenes and indenes, since said molecules are commercially available or can be easily synthesized.

[0048] As substituted fluorenyl groups, those substituted at positions 2, 7, 3 or 6 may be mentioned, in particular 2,7-di(tert-butyl)fluorenyl and 3,6-di(tert-butyl)fluorenyl. As shown in the figure below, positions 2, 3, 6 and 7 represent the positions of the carbon atoms of the ring, respectively, and position 9 corresponds to the carbon atom to which the bridge P is attached.

[0049]

[0050] As substituted cyclopentadienyl, mention may be made of those substituted at position 2 (or 5) as well as at position 3 (or 4), in particular those substituted at position 2, more particularly tetramethylcyclopentadienyl. Position 2 (or 5) denotes the position of the carbon atom adjacent to the carbon atom to which the bridge P is attached, as shown in the figure below. As a reminder, substitution at position 2 or 5 is also referred to as substitution at the alpha position relative to the bridge.

[0051]

[0052] As substituted indenyl groups, mention may in particular be made of those substituted in position 2, more particularly 2-methylindenyl or 2-phenylindenyl. Position 2 denotes the position of the carbon atom adjacent to the carbon atom to which the bridge P is attached, as shown in the figure below.

[0053]

[0054] Preferably, Cp 1 and Cp 2 The same or different, is cyclopentadiene, substituted fluorenyl, substituted indenyl or a substituted indenyl of formula C 13 More preferably, Cp 1 and Cp 2 The same or different, is a substituted fluorenyl or a C 13 H8 is an unsubstituted fluorenyl group. Advantageously, Cp 1 and Cp 2 Formula C 13 The unsubstituted fluorenyl group of H8 is represented by the symbol Flu.

[0055] Even more preferably, the metallocene is of formula (I-1), (I-2), (I-3), (I-4) or (I-5):

[0056] [Me2Si(Flu)2Nd(μ-BH4)2Li(THF)] (I-1)

[0057] [{Me2SiFlu2Nd(μ-BH4)2Li(THF)}2] (I-2)

[0058] [Me2SiFlu2Nd(μ-BH4)(THF)] (I-3)

[0059] [{Me2SiFlu2Nd(μ-BH4)(THF)}2] (I-4)

[0060] [Me2SiFlu2Nd(μ-BH4)] (I-5)

[0061] Where Flu represents C 13 H8 group.

[0062] The metallocene used for the synthesis of the catalyst system can be in the form of a crystalline powder or a non-crystalline powder, or in a single crystal form.Metallocene can be in monomeric form or dimer form, and these forms depend on the preparation method of metallocene, as described in for example patent application WO 2007 / 054224 A2 or WO 2007 / 054223 A2.Metallocene can be conventionally prepared by a method similar to the method described in patent application WO 2007 / 054224 A2 or WO 2007 / 054223 A2, particularly by reacting the alkali metal salt of the part with the borohydride of the rare earth metal neodymium in a suitable solvent (for example ether (such as diethyl ether or tetrahydrofuran), or any other solvent known to those skilled in the art) under inertia and anhydrous conditions to prepare.After the reaction, by technology known to those skilled in the art, for example filter or separate out from the second solvent, thereby metallocene is separated from byproduct of reaction.Finally, the metallocene is dried and separated in solid form.

[0063] The organomagnesium reagent is another basic component of the catalyst system and is a co-catalyst of the catalyst system. Generally, the organomagnesium reagent can be a diorganomagnesium reagent or an organomagnesium halide. The organomagnesium reagent can be of formula (IIa), (IIb), (IIc) or (IId), wherein R 3 , R 4 , R 5 and R B The same or different, indicating a carbon-based group, R A represents a divalent carbonyl group, X is a halogen atom, m is a number greater than or equal to 1, preferably equal to 1,

[0064] Mg 3 R 4 (IIa)

[0065] XOtM 5 (IIb)

[0066] R B -(Mg-R A ) m -Mg-R B (IIc)

[0067] X-Mg-R A -Mg-X (IId).

[0068] R A may be a divalent aliphatic hydrocarbon chain, optionally interrupted by one or more oxygen atoms or sulfur atoms or one or more arylene groups,

[0069] The term "carbonyl group" means a group containing one or more carbon atoms. The carbonyl group may be a hydrocarbyl group (hydrocarbon group) or a heterohydrocarbyl group, i.e. a group containing one or more heteroatoms in addition to carbon atoms and hydrogen atoms. As organomagnesium reagents containing heterohydrocarbyl groups, compounds described as transfer agents in patent application WO 2016 / 092227 A1 may be suitable for use. 3 , R 4 , R 5 , R B and R A The carbyl group represented by is preferably a hydrocarbyl group.

[0070] Preferably, R A Contains 3 to 10 carbon atoms, in particular 3 to 8 carbon atoms.

[0071] Preferably, R A Preferably, R A is a branched or linear alkanediyl, cycloalkanediyl or xylenediyl group. More preferably, R A Even more preferably, R A is an alkanediyl radical containing 3 to 10 carbon atoms. Advantageously, R A is an alkanediyl radical containing 3 to 8 carbon atoms. Very advantageously, R A 1,3-Propanediyl, 1,4-butanediyl, 1,5-pentanediyl, 1,6-hexanediyl, 1,7-heptanediyl and 1,8-octanediyl are particularly suitable as radical R. A .

[0072] By R 3 , R 4 , R 5 and R B The carbonyl groups represented can be aliphatic or aromatic. They can contain one or more heteroatoms, such as oxygen atoms, nitrogen atoms, silicon atoms or sulfur atoms. Preferably, they are alkyl, phenyl or aryl. They can contain 1 to 20 carbon atoms.

[0073] By R 3 , R 4 , R 5 and R B The alkyl groups represented may contain 2 to 10 carbon atoms and are especially ethyl, butyl, octyl.

[0074] By R 3 , R 4 , R 5 and R B The aryl group represented may contain 7 to 20 carbon atoms and is especially a phenyl group substituted by one or more alkyl groups (eg methyl, ethyl, isopropyl).

[0075] According to a particular embodiment of the present invention, R 3 A benzene ring substituted with a magnesium atom, one of the carbon atoms of the benzene ring ortho to the magnesium is substituted with a methyl group, an ethyl group, or an isopropyl group, or a ring is formed with the carbon atom closest to the benzene ring and meta to the magnesium, another carbon atom of the benzene ring ortho to the magnesium is substituted with a methyl group, an ethyl group, or an isopropyl group, and R 4 In other words, according to this particular embodiment, the methyl, ethyl and isopropyl substituents of the benzene ring are in the ortho position relative to the magnesium atom. 3 It can be 1,3-dimethylphenyl, 1,3-diethylphenyl, mesityl or 1,3,5-triethylphenyl, R 4 It may be ethyl, butyl or octyl.

[0076] According to a particular embodiment of the present invention, R 3 and R 4 is an alkyl group containing 2 to 10 carbon atoms, especially ethyl, butyl or octyl.

[0077] R 5 Preferred is an alkyl group containing 2 to 10 carbon atoms, more preferably an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group or an octyl group.

[0078] R B It may contain a benzene ring substituted by a magnesium atom, one of the carbon atoms of the benzene ring ortho to the magnesium being substituted by a methyl group, an ethyl group, or an isopropyl group, or the benzene ring may form a ring with the carbon atom closest to the benzene ring and meta to the magnesium, and another carbon atom of the benzene ring ortho to the magnesium being substituted by a methyl group, an ethyl group, or an isopropyl group. B It may be 1,3-dimethylphenyl, 1,3-diethylphenyl, mesityl or 1,3,5-triethylphenyl.

[0079] For example, suitable organomagnesium reagents are butylethylmagnesium, butyloctylmagnesium, ethylmagnesium chloride, butylmagnesium chloride, amylmagnesium chloride, ethylmagnesium bromide, butylmagnesium bromide, amylmagnesium bromide, octylmagnesium chloride, octylmagnesium bromide, 2,6-dimethylphenylbutylmagnesium, 2,6-diethylphenylethylmagnesium, butyl-2-mesitylmagnesium, ethyl-2-mesitylmagnesium, 2,6-diethylphenylbutylmagnesium, 2,6-diethylphenylethylmagnesium, 2,6-diisopropylphenylbutylmagnesium , 2,6-diisopropylphenylethylmagnesium, 2,4,6-triethylphenylbutylmagnesium, 2,4,6-triethylphenylethylmagnesium, 2,4,6-triisopropylphenylbutylmagnesium, 2,4,6-triisopropylphenylethylmagnesium, 1,3-di(magnesium bromide)propylenediyl, 1,3-di(magnesium chloride)propylenediyl, 1,5-di(magnesium bromide)pentanediyl, 1,5-di(magnesium chloride)pentanediyl, 1,8-di(magnesium bromide)octanediyl, 1,8-di(magnesium chloride)octanediyl.

[0080] The organomagnesium compound of formula (IIc) can be prepared by a method comprising: making a compound of formula X'Mg-R A -MgX' first organomagnesium reagent with formula R B -Mg-X', wherein X' represents a halogen atom, preferably bromine or chlorine, R B and R A As defined above. X' is more preferably a bromine atom. The stoichiometry used in the reaction determines the value of m in formula (IIc). For example, a molar ratio of 0.5 between the amount of the first organomagnesium reagent and the amount of the second organomagnesium reagent is favorable for the formation of an organomagnesium compound of formula (IIc) with m equal to 1, while a molar ratio greater than 0.5 will be more favorable for the formation of an organomagnesium compound of formula (IIc) with m greater than 1.

[0081] In order to carry out the reaction of the first organomagnesium reagent and the second organomagnesium reagent, the solution of the second organomagnesium reagent is usually added to the solution of the first organomagnesium reagent. The solution of the first organomagnesium reagent and the solution of the second organomagnesium reagent are usually solutions in ether (such as diethyl ether, dibutyl ether, tetrahydrofuran, methyltetrahydrofuran or a mixture of two or more of these ethers). Hydrocarbon aliphatic or aromatic solvents can be added to the ether as cosolvents. Preferably, the concentrations of the first organomagnesium reagent solution and the second organomagnesium reagent solution are 0.01mol / L to 3mol / L and 0.02mol / L to 5mol / L, respectively. More preferably, the concentrations of the first organomagnesium reagent solution and the second organomagnesium reagent solution are 0.1mol / L to 2mol / L and 0.2mol / L to 4mol / L, respectively.

[0082] The first organomagnesium reagent and the second organomagnesium reagent (Grignard reagent) can be prepared in advance in a reactor from metallic magnesium and a suitable halogenated precursor. For the first organomagnesium reagent and the second organomagnesium reagent, each precursor is a compound of the formula X'-R A -X' and R B -X', R A , R B and X' are as defined above. The Grignard reagent is usually prepared by adding the precursor to magnesium metal, which is usually in the form of fragments. Preferably, iodine (I2) is introduced into the reactor, usually in the form of droplets, before adding the precursor, so as to activate the Grignard reaction in a known manner.

[0083] Alternatively, the organomagnesium compound of formula (IIc) can be prepared by treating the organomagnesium compound of formula MR A -M organometallic compound and formula R B -Mg-X', wherein M represents a lithium, sodium or potassium atom, X', R B and R AAs defined above. Preferably, M represents a lithium atom, in which case the formula MR A The organometallic compound of -M is an organolithium reagent.

[0084] The reaction of the organolithium reagent and the organomagnesium reagent is usually carried out in ether (e.g., diethyl ether, dibutyl ether, tetrahydrofuran, methyltetrahydrofuran, methylcyclohexane, toluene, or a mixture thereof). The reaction is also usually carried out at a temperature ranging from 0°C to 60°C. Preferably, the contact is carried out at a temperature between 0°C and 23°C. Formula MR A -M organic metal compound with formula R B The organomagnesium reagent of -Mg-X' is preferably contacted by the organometallic compound MR A -M solution is added to the organomagnesium reagent R B -Mg-X' solution. A The solution of -M is usually in a hydrocarbon solvent (preferably n-hexane, cyclohexane or methylcyclohexane), and the organomagnesium reagent R B The solution of -Mg-X' is usually in ether (preferably diethyl ether or dibutyl ether). Preferably, the organometallic compound MR A -M solution and organomagnesium reagent R B The concentrations of the solutions of -Mg-X' are 0.01 mol / L to 1 mol / L and 0.02 mol / L to 5 mol / L, respectively. More preferably, the organometallic compound MR A -M solution and organomagnesium reagent R B The concentrations of the solutions of -Mg-X' are 0.05 mol / L to 0.5 mol / L and 0.2 mol / L to 3 mol / L, respectively.

[0085] As with any synthesis carried out in the presence of an organometallic compound, the synthesis described for the synthesis of organomagnesium reagents is carried out in a stirred reactor under anhydrous conditions and an inert atmosphere. Typically, solvents and solutions are used under anhydrous nitrogen or argon.

[0086] When the organomagnesium reagent of formula (IIc) is formed, it is typically recovered in solution after filtration under an inert anhydrous atmosphere. It can be stored in solution in a sealed container (eg, a capped bottle) at a temperature between -25°C and 23°C prior to use.

[0087] Compounds of formula (IId) as Grignard reagents are described, for example, in the book "Advanced Organic Chemistry" by J. March (4th edition, 1992, pages 622-623) or in the book "Handbook of Grignard Reagents" edited by Gary S. Silverman and Philip E. Rakita (1996, pages 502-503). They can be prepared by reacting metallic magnesium with a compound of formula XR A -X dihalogen compound contact synthesis, R A As defined according to the invention. Regarding their synthesis, reference may be made, for example, to the various volumes of the compilation "Organic Synthesis".

[0088] The compounds of the formula (IIa) and (IIb) are also well known as Grignard reagents, and some of them are even commercial products. For their synthesis, reference can be made, for example, to the compilation volumes of "Organic Synthesis".

[0089] As with any organomagnesium compound, the organomagnesium compound constituting the catalyst system, in particular the organomagnesium compound of formula (IIa), (IIb), (IIc) or (IId), may be in the form of a monomeric substance or in the form of a polymeric substance. For example, the organomagnesium reagent (IIc) may be in the form of a monomeric substance (R B -(Mg-R A ) m -Mg-R B )1, or in the form of a polymer substance (R B -(Mg-R A ) m -Mg-R B ) p (wherein p is an integer greater than 1), especially a dimer (R B -(Mg-R A ) m -Mg-R B )2, wherein m is as defined above. Similarly, it is also exemplified that the organomagnesium reagent of formula (IId) can be in the form of a monomeric substance (X-Mg-R A -Mg-X)1, or in the form of a polymer substance (X-Mg-R A -Mg-X) p (p is an integer greater than 1), especially a dimer (X-Mg-R A -Mg-X)2.

[0090] Furthermore, whether in the form of a monomer or a polymer, the organomagnesium reagent may also be in the form of a complex with one or more molecules of a solvent (preferably an ether such as diethyl ether, tetrahydrofuran or methyltetrahydrofuran).

[0091] In formulae (IIb) and (IId), X is preferably a bromine atom or a chlorine atom.

[0092] According to a very preferred variant of the invention, the organomagnesium reagent is an organomagnesium halide, preferably of formula (IIb) or (IId), more preferably of formula (IIb), even more preferably of formula (IIb) XMgR 5 , where X is a chlorine atom or a bromine atom, R 5 is alkyl or aryl, preferably alkyl. According to this very preferred variant, R 5 Advantageously, it is an alkyl group containing 2 to 10 carbon atoms, more preferably ethyl, propyl, butyl, pentyl, hexyl, heptyl or octyl. When the organomagnesium reagent is a halide of an organomagnesium reagent of formula (IIb) or (IId), preferably of formula (IIb), the process of the invention allows the highest yield of a polymer with a keto functional group at one of its chain ends, compared to the yield obtained using a diorganomagnesium reagent.

[0093] The amount of the cocatalyst and the metallocene in the reaction satisfies that the ratio of the molar number of Mg of the cocatalyst to the molar number of the rare earth metal (neodymium) of the metallocene is preferably 0.5 to 200, more preferably 1 to less than 20. These preferred ranges are applicable to any embodiment of the present invention. The value range of 1 to less than 20 is particularly conducive to obtaining a copolymer with a high molar mass.

[0094] According to one embodiment, the catalytic system can be conventionally prepared by a method similar to that described in patent application WO 2007 / 054224A2 or WO2007 / 054223A2. For example, the cocatalyst (in this case, an organomagnesium reagent) and the metallocene are reacted in a hydrocarbon solvent, typically at a temperature ranging from 20° C. to 80° C., for a period of time (between 5 minutes and 60 minutes). The catalytic system is typically prepared in an aliphatic hydrocarbon solvent (such as methylcyclohexane) or an aromatic hydrocarbon solvent (such as toluene). Typically, after synthesis, the catalytic system is used as is in step a).

[0095] According to another embodiment, the catalytic system can be prepared by a method similar to that described in patent application WO 2017 / 093654A1 or patent application WO 2018 / 020122A1: it is called preformed type. For example, the organomagnesium reagent and the metallocene are reacted in a hydrocarbon solvent, usually at a temperature of 20°C to 80°C for 10 to 20 minutes to obtain a first reaction product, and then the preformed monomer is reacted with the first reaction product at a temperature ranging from 40°C to 90°C for 1 hour to 12 hours. The preformed monomer is preferably used in a molar ratio (preformed monomer / metal of the metallocene) ranging from 5 to 1000, preferably 10 to 500. Before being used for polymerization, the preformed catalytic system can be stored under an inert atmosphere, especially at a temperature ranging from -20°C to room temperature (23°C). According to this second embodiment, the preformed catalytic system has a preformed monomer selected from 1,3-diene, ethylene and mixtures thereof as its essential component. In other words, in addition to the metallocene and the cocatalyst, the "preformed" catalytic system also comprises a preformed monomer. The 1,3-diene used as the pre-formed monomer may be 1,3-butadiene, isoprene or a 1,3-diene of the formula CH2=CR 6 -CH=CH2 1,3-diene, symbol R 6 denotes a hydrocarbyl group containing from 3 to 20 carbon atoms, in particular myrcene or β-farnesene. The preformed monomer is preferably 1,3-butadiene.

[0096] The catalytic system is usually present in a solvent, which is preferably a solvent for preparing the catalytic system. The concentration of the rare earth metal (i.e., neodymium) of the metallocene is preferably in the range of 0.0001 mol / L to 0.2 mol / L, more preferably in the range of 0.001 mol / L to 0.03 mol / L.

[0097] As with any synthesis carried out in the presence of an organometallic compound, the synthesis of the organomagnesium reagent and the synthesis of the catalyst system are carried out under anhydrous conditions and in an inert atmosphere. Typically, the reaction is started using anhydrous solvents and compounds under anhydrous nitrogen or argon.

[0098] The polymerization of the monomer mixture is preferably carried out continuously or in batches in a solution. The polymerization solvent is generally an aromatic hydrocarbon solvent or an aliphatic hydrocarbon solvent, such as toluene, cyclohexane or methylcyclohexane, or a mixture of two of them, or even a mixture of three. The monomer mixture can be introduced into a reactor comprising a polymerization solvent and a catalyst system, or conversely, the catalyst system can be introduced into a reactor comprising a polymerization solvent and a monomer mixture. The monomer mixture and the catalyst system can be introduced simultaneously into a reactor comprising a polymerization solvent, particularly in the case of continuous polymerization. The polymerization is generally carried out under anhydrous conditions and in the absence of oxygen and optionally in the presence of an inert gas. The range of the polymerization temperature is generally 40°C to 150°C, preferably 40°C to 120°C. Those skilled in the art adjust the polymerization conditions, such as the polymerization temperature, the concentration of each reagent, and the pressure in the reactor according to the monomer mixture composition, the polymerization reactor, and the desired microstructure and macrostructure of the copolymer chain.

[0099] The polymerization is preferably carried out under a constant monomer pressure. The continuous addition of each monomer or of one monomer can be carried out in a polymerization reactor, in which case the polymerization reactor is a feed reactor. This embodiment is most particularly suitable for statistical incorporation of monomers. Preferably, the polymerization in step a) is a statistical polymerization, which is reflected in the statistical incorporation of the monomers in the monomer mixture used in step a).

[0100] Once the desired degree of monomer conversion has been achieved in the polymerization reaction in step a), the functionalization reaction in step b) is carried out.

[0101] Step b) of the process according to the invention brings a functionalizing agent (a compound containing a nitrile function) into contact with the reaction product of step a).

[0102] Preferably, step b) is also carried out in a hydrocarbon solvent. Advantageously, it is carried out in the reaction medium produced in step a). It is usually carried out in the reaction medium by adding the compound containing the nitrile functional group to the reaction product of step a) under stirring.

[0103] Prior to adding the compound containing the nitrile functional group, the reactor is preferably degassed and rendered inert (also referred to as inertization). Degassing the reactor can remove residual gaseous monomers and is also beneficial for adding the compound containing the nitrile functional group to the reactor. Making the reactor inert (e.g., with nitrogen) helps prevent the deactivation of carbon-metal bonds present in the reaction medium and necessary for the functionalization reaction of the polymer. The compound containing the nitrile functional group can be added undiluted or diluted in a hydrocarbon aliphatic or aromatic solvent. The compound containing the nitrile functional group is contacted with the reaction product in step a) for the time required for the functionalization reaction of the polymer chain ends, preferably under stirring. The functionalization reaction can usually be monitored by chromatographic analysis to track the consumption of the compound containing the nitrile functional group. The functionalization reaction is preferably carried out at a temperature ranging from 23°C to 120°C, preferably from 40°C to 100°C.

[0104] The functionalization reaction (step b) is preferably carried out with at least one molar equivalent of nitrile functional groups per mole of carbon-magnesium bonds of the organomagnesium reagent. The ratio between the number of molar equivalents of nitrile functional groups and the number of carbon-magnesium bonds per mole of the organomagnesium reagent can vary widely, provided that it is at least 1, i.e. at least one molar equivalent of nitrile functional groups is used per mole of carbon-magnesium bonds of the organomagnesium reagent. An excess of the compound containing nitrile functional groups can be used, but preferably no more than 3 molar equivalents of nitrile functional groups are used per mole of carbon-magnesium bonds, in particular for cost reasons. For example, in an organomagnesium halide of formula (IIb), such as n-butylmagnesium chloride, there is one mole of carbon-magnesium bonds per mole of halide; in a magnesium reagent of formula (IIa), such as butyloctylmagnesium (BOMAG), or in a magnesium reagent of formula (IId), there are two moles of carbon-magnesium bonds per mole of magnesium reagent. One mole of a compound containing a single nitrile functional group is equivalent to one molar equivalent of nitrile functional groups; one mole of a compound containing two nitrile functional groups is equivalent to two molar equivalents of nitrile functional groups; more generally, one mole of a compound containing n nitrile functional groups is equivalent to n molar equivalents of nitrile functional groups, where n is an integer greater than or equal to 1.

[0105] The compound containing nitrile functional group can be aliphatic compound or aromatic compound, is preferably aromatic compound, preferably contains single nitrile functional group.The compound containing nitrile functional group is generally the compound that alkyl chain is replaced by single nitrile functional group or multiple nitrile functional group (preferably single nitrile functional group).The alkyl chain of the compound containing nitrile functional group also can be replaced by another functional group, and this another functional group contains one or more heteroatoms selected from oxygen atom, sulphur atom, nitrogen atom and silicon atom.The alkyl chain of the compound containing nitrile functional group can be linear, annular or branched.

[0106] Preferably, the compound containing a nitrile functional group contains a second functional group selected from ether, thioether, protected amine, tertiary amine, alkoxysilane and imidazole functional groups, preferably an ether functional group, a tertiary amine functional group, an alkoxysilane functional group or an imidazole functional group.

[0107] According to a first embodiment of the present invention, the compound containing the nitrile functional group is the alkane replaced by the nitrile functional group (preferred single nitrile functional group).The length of the alkyl chain of the alkane replaced by the nitrile functional group does not have inherent restriction, and the carbon number in the alkyl chain can have very large variation, for example, is 1 to 11 carbon atom.The selection of the alkane replaced by the nitrile functional group can be because it is commercially available or easily synthesized.Especially, be suitable for using acetonitrile or methyl cyanide, propionitrile or ethyl cyanide, butyronitrile or propyl cyanide, valeronitrile or butyl cyanide, capronitrile or amyl cyanide, dodecanitrile or lauric nitrile.

[0108] According to a second embodiment of the present invention, the compound containing the nitrile functional group is an alkane substituted by the nitrile functional group and another functional group, and the another functional group contains one or more heteroatoms selected from oxygen atoms, sulfur atoms, nitrogen atoms and silicon atoms and is different from the nitrile functional group. According to this embodiment, the compound containing the nitrile functional group preferably contains a single nitrile functional group. Another functional group is preferably selected from ether, thioether, protected amine, tertiary amine and alkoxysilane functional group, more preferably tertiary amine functional group or alkoxysilane functional group. Particularly suitable for using dialkylaminoalkanenitrile, alkoxyalkanenitrile, trialkoxysilylalkanenitrile, alkyldialkoxysilylalkanenitrile and dialkylalkoxysilylalkanenitrile, wherein alkyl and alkoxy chain preferably contain 1 to 2 carbon atoms, and alkane chain preferably contains 2 to 6 carbon atoms, more preferably contains 2 to 3 carbon atoms. The selection of substituted alkanes can be due to whether it is commercially available or easily synthesized. Mention may be made in this regard of dimethylaminopropionitrile, dimethylaminobutyronitrile, diethylaminopropionitrile, diethylaminobutyronitrile, methoxypropionitrile, methoxybutyronitrile, ethoxypropionitrile, ethoxybutyronitrile, triethoxysilylpropionitrile, triethoxysilylbutyronitrile, trimethoxysilylpropionitrile, trimethoxysilylbutyronitrile, methyldimethoxysilylpropionitrile, methyldimethoxysilylbutyronitrile, methyldiethoxysilylpropionitrile, methyldimethoxysilylbutyronitrile, ethyldimethoxysilylpropionitrile, ethyldimethoxysilylbutyronitrile, ethyldiethoxysilylpropionitrile, ethyldiethoxysilylbutyronitrile, dimethylmethoxysilylpropionitrile, dimethylmethoxysilylbutyronitrile, dimethylmethoxysilylpropionitrile, dimethylmethoxysilylbutyronitrile, diethylmethoxysilylpropionitrile, diethylmethoxysilylbutyronitrile, diethylethoxysilylpropionitrile and diethylethoxysilylbutyronitrile.

[0109] According to the particularly preferred third embodiment, the compound containing the nitrile functional group is an aromatic hydrocarbon substituted by a nitrile functional group (preferably a single nitrile functional group). Aromatic hydrocarbons can also carry one or more other substituents except the nitrile functional group. Aromatic hydrocarbons can be substituted by a hydrocarbyl chain or a functional group, and the functional group is different from the nitrile functional group and contains one or more heteroatoms, such as an oxygen atom, a sulphur atom, a nitrogen atom or a silicon atom. The functional group is preferably selected from ether, thioether, protected amine, tertiary amine and imidazole functional groups. Aromatic hydrocarbons can be substituted by a hydrocarbyl chain, and the hydrocarbyl chain can also be substituted by a functional group selected from ether, thioether, protected amine, tertiary amine and imidazole functional groups. The hydrocarbyl chain in the compound containing the nitrile functional group is preferably an alkyl group. The alkyl group in the compound containing the nitrile functional group preferably contains 1 to 6 carbon atoms, more preferably contains 1 to 3 carbon atoms.

[0110] The compound containing the nitrile functional group is more preferably benzonitrile, benzonitrile or substituted benzonitrile, preferably substituted by a functional group selected from ether, thioether, protected amine, tertiary amine and imidazole functional group, more preferably substituted by ether, tertiary amine or imidazole functional group. Benzonitrile for the purpose of the present invention is generally formula (III), wherein the symbols X1 to X5 are identical or different, each representing a hydrogen atom, an alkyl group or a functional group selected from ether, thioether, protected amine, tertiary amine and imidazole functional group (preferably ether functional group, tertiary amine functional group or imidazole functional group). Advantageously, four of the symbols X1 to X5 in formula (III) represent hydrogen atoms or alkyl groups, preferably hydrogen atoms, and the fifth symbol represents an ether functional group, thioether functional group, protected amine functional group, tertiary amine functional group or imidazole functional group, preferably ether functional group, tertiary amine functional group or imidazole functional group. The alkyl group of the benzonitrile compound preferably contains 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms. Particularly suitable are benzonitrile and the following substituted benzonitriles, whether para-substituted, meta-substituted or ortho-substituted, preferably para-substituted or ortho-substituted, for example alkoxybenzonitrile (e.g. methoxybenzonitrile, ethoxybenzonitrile), thioalkoxybenzonitrile (e.g. thiomethoxybenzonitrile, thioethoxybenzonitrile), N,N-dialkylaminobenzonitrile (e.g. N,N-dimethylaminobenzonitrile, N,N-diethylaminobenzonitrile), imidazolylbenzonitrile (e.g. 2-(1H-imidazol-1-yl)benzonitrile or 4-(1H-imidazol-1-ylmethyl)benzonitrile).

[0111]

[0112] Once the chain ends have been modified, step b) is followed by step c). Step c) is generally a hydrolysis reaction which allows the formation of keto functions in the polymer chain and, where appropriate, deactivates the reactive sites still present in the reaction medium. The hydrolysis reaction is generally carried out by adding water to the reaction medium (or vice versa), optionally in the presence of an acid. Generally, the reaction medium resulting from step b) is contacted with an aqueous hydrochloric acid solution. The hydrolysis reaction can be carried out at a temperature ranging from 0° C. to 100° C., preferably at room temperature (23° C.) or at the reaction temperature of step b), or even at a temperature ranging from room temperature to the reaction temperature of step b). In the case where the polymer also contains protected amine functions or alkoxysilane functions, step c) can be followed or accompanied by a reaction of the hydrolysis of the protected amine functions into amine functions or of the hydrolysis of the alkoxysilane functions into silanol functions, as described, for example, in patent application EP 2 266 819 A1.

[0113] After step c), the polymer can be separated from the reaction medium according to methods known to those skilled in the art, for example by evaporation of the solvent under reduced pressure or by steam stripping. According to a variant of the invention, step c) and separation of the polymer from the reaction medium can be carried out in the same operation (for example a steam stripping operation), in particular in the presence of an acid.

[0114] The polymer synthesized by the method according to the present invention has the characteristic of carrying a ketone functional group (especially a ketone functional group of a monomer unit of the polymer) at the chain end (i.e. at one of its chain ends). The expression "a ketone functional group of a monomer unit of the polymer is directly connected to a CO group" means a ketone functional group in which the carbon of the CO group of the ketone functional group forms a covalent bond with a carbon atom of a monomer unit of the polymer. Preferably, the polymer carries a second functional group, which is carried on the same chain end as the ketone functional group and is selected from ether, thioether, amine, alkoxysilane, silanol and imidazole functional groups. The second functional group is preferably an amine functional group (preferably a tertiary amine functional group), an alkoxysilane functional group, a silanol functional group or an imidazole functional group, more preferably a tertiary amine functional group, a silanol functional group or an imidazole functional group. The alkoxysilane functional group is advantageously of the formula Si(OR) 3- n R n , R is the same or different and is methyl or ethyl, and n is an integer ranging from 0 to 3.

[0115] According to a first variant, the polymer carries a keto function at only one of its chain ends. This variant can be carried out by the synthesis process according to the invention, wherein the organomagnesium reagent is of the formula (IIa) and (IIb).

[0116] According to a second variant, the polymer carries a keto function at each of its chain ends. This variant can be carried out by the synthesis process according to the invention, wherein the organomagnesium reagent is of formula (IIc) and (IId).

[0117] According to a first embodiment applicable to the first variant and the second variant, the keto functional group is a substituent of an aliphatic hydrocarbyl chain. The hydrocarbyl chain may be linear, cyclic or branched. The hydrocarbyl chain is preferably an alkyl group containing 1 to 11 carbon atoms. Particularly suitable hydrocarbyl chains include ethyl, propyl, amyl and lauryl. The polymer defined according to the first embodiment can be prepared by a first embodiment of the method according to the invention.

[0118] According to a second way applicable to the first variant and the second variant, the keto functional group is a substituent of an aliphatic hydrocarbon chain which is also substituted by another functional group containing one or more heteroatoms selected from oxygen atoms, sulfur atoms, nitrogen atoms and silicon atoms and different from the keto functional group. The other functional group is preferably selected from ether, thioether and amine functional groups, more preferably from tertiary amine functional groups, alkoxysilane functional groups or silanol functional groups, even more preferably from tertiary amine functional groups or silanol functional groups. The polymer defined according to this second way can be prepared by carrying out the second embodiment of the method according to the invention.

[0119] According to the third way applicable to the first variant and the second variant, the ketone functional group is a substituent of an aryl (preferably phenyl). The aryl group can also be substituted by a hydrocarbyl chain or a functional group, and the functional group is different from the nitrile functional group and contains one or more heteroatoms, such as an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom. The functional group is preferably selected from ethers, thioethers and amine functional groups, preferably tertiary amines and imidazoles. Aromatic hydrocarbons can be substituted by a hydrocarbyl chain, and the hydrocarbyl chain is also substituted by a functional group selected from ethers, thioethers, amine (preferably tertiary amine) functional groups. The hydrocarbyl chain substituted with an aryl (particularly phenyl) is preferably an alkyl. These alkyl groups preferably contain 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms. The polymer limited according to this third way can be prepared by carrying out the third embodiment of the method according to the present invention.

[0120] According to a fourth way applicable to the first variant and the second variant, the ketone functional group is a substituent of an alkyl-substituted phenyl, or is a functional group selected from ether, thioether, amine (preferably tertiary amine) and imidazole functional group, preferably an ether functional group, a tertiary amine functional group or an imidazole functional group. The alkyl substituent on the phenyl preferably contains 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms. The polymer defined in this fourth way can be prepared by carrying out the third embodiment of the method according to the invention, wherein the compound containing the nitrile functional group is a substituted benzonitrile.

[0121] A second subject of the invention is a copolymer of ethylene, 1,3-diene and optionally a vinyl aromatic compound, which carries at one of its chain ends a ketone function and optionally a second functional group, which is carried at the same chain end as the ketone function and is chosen from ether, thioether, amine, alkoxysilane, silanol and imidazole functions. It can be obtained by an alternative form of the process according to the invention, in which the ethylene-containing monomer mixture to be polymerized is a mixture of ethylene, 1,3-diene and optionally a vinyl aromatic compound. The two variants of the polymers obtainable by the process according to the invention described above and the four ways described as being applicable to these two variants can be applied to the copolymer that is the second subject of the invention. The amine function carried by the copolymer according to the invention is preferably a tertiary amine function.

[0122] The copolymer also has the essential feature of containing more than 50 mol % of ethylene units, this percentage being expressed relative to all the units resulting from the polymerization of the monomers in the monomer mixture, in this case ethylene, 1,3-diene and, where appropriate, vinyl aromatic compounds. 1,3-Diene and vinyl aromatic compounds are as defined according to any one of the embodiments of the process according to the invention.

[0123] Preferably, the copolymer further contains 1,2-cyclohexane ring units. The 1,2-cyclohexane ring units are of formula (IV).

[0124]

[0125] When the copolymer contains 1,2-cyclohexane ring units, it is a copolymer according to a special embodiment of the invention in which the 1,3-diene is 1,3-butadiene or a mixture of 1,3-dienes, one of which is 1,3-butadiene, the ring units resulting from the specific insertion of ethylene and 1,3-butadiene monomers in the polymer chain, in addition to the conventional ethylene and 1,3-butadiene units, respectively -(CH2-CH2)-, (CH2-CH=CH-CH2)- and (CH2-CH(C=CH2))-. It is obtained in particular by an embodiment of the process according to the invention in which the metallocene of the catalyst system has two substituted or unsubstituted fluorenyl groups as ligands. The mechanism for obtaining this microstructure is described, for example, in Macromolecules 2009 (42, 3774-3779). When the polymer according to the invention contains 1,2-cyclohexane ring units, it preferably contains not more than 15 mol % of 1,2-cyclohexane ring units, this percentage being expressed relative to all units resulting from the polymerization of the monomers in the monomer mixture.

[0126] According to any of the embodiments of the present invention, the copolymer according to the present invention is preferably a statistical copolymer.

[0127] The third subject of the present invention is a polyethylene carrying a keto functional group at one of its chain ends and a second functional group, the second functional group being carried at the same chain end as the keto functional group and being selected from ether, thioether, amine, alkoxysilane, silanol and imidazole functional groups. It can be obtained by an alternative form of the process according to the invention, in which the ethylene-containing monomer mixture to be polymerized is a monomer mixture consisting only of ethylene. The two variant forms of the polymers obtained by the process according to the invention described above, plus the second way or the fourth way described as being applicable to these two variant forms, can be applied to the polyethylene as the third subject of the present invention. The amine functional group carried by the polyethylene according to the invention is preferably a tertiary amine functional group.

[0128] The polymers according to the invention, whether copolymers or polyethylenes (the second subject of the invention and the third subject of the invention, respectively), can be used in compositions containing one or more ingredients or components other than the polymers according to the invention, such as additives commonly used in polymer compositions (such as antioxidants, plasticizers, pigments or fillers).

[0129] In summary, the present invention is advantageously carried out according to any one of the following embodiments 1 to 34:

[0130] Embodiment 1: Process for preparing a polymer containing more than 50 mol % of ethylene units and carrying a keto functional group at one of its chain ends,

[0131] The method comprises the consecutive steps a), b) and c):

[0132] - step a) consists in polymerizing a monomer mixture containing ethylene in the presence of a catalytic system based on at least one metallocene of formula (I) and an organomagnesium reagent,

[0133] {P(Cp 1 )(Cp 2 )Nd(BH4) (1+y)- L y -N x} (I)

[0134] Cp 1 and Cp 2 are the same or different and are selected from fluorenyl, cyclopentadienyl and indenyl, which groups are substituted or unsubstituted,

[0135] P is the bridge Cp 1 and Cp 2 Two groups and groups containing silicon atoms or carbon atoms,

[0136] Nd represents a neodymium atom,

[0137] L represents an alkali metal selected from lithium, sodium and potassium,

[0138] N represents an ether molecule,

[0139] x can be an integer or non-integer greater than or equal to 0.

[0140] y is an integer greater than or equal to 0,

[0141] - step b) is to react a compound containing a nitrile functional group with the product of the polymerization reaction of step a),

[0142] - Step c) is a hydrolysis reaction,

[0143] The polymer is polyethylene or a copolymer of ethylene with a 1,3-diene and optionally a vinyl aromatic compound.

[0144] Embodiment 2: The method according to embodiment 1, wherein the 1,3-diene monomer is 1,3-butadiene, isoprene, myrcene, β-farnesene or a mixture thereof.

[0145] Embodiment 3: The method according to Embodiment 1 or 2, wherein the monomer mixture is ethylene.

[0146] Embodiment 4: The method according to embodiment 1 or 2, wherein the monomer mixture is a mixture of ethylene and 1,3-diene.

[0147] Embodiment 5: The method according to embodiment 1 or 2, wherein the monomer mixture is a mixture of ethylene, 1,3-diene and a vinyl aromatic compound.

[0148] Embodiment 6: The method according to Embodiment 5, wherein the vinyl aromatic compound is styrene.

[0149] Embodiment 7: The method according to any one of embodiments 1 to 6, wherein the monomer mixture in step a) contains more than 50 mol% of ethylene, the percentage being expressed relative to the total moles of monomers in the monomer mixture in step a).

[0150] Embodiment 8: The method according to any one of embodiments 1 to 7, wherein Cp 1 and Cp 2 The same or different, is a substituted fluorenyl or a C 13 The unsubstituted fluorenyl group of H8 is preferably an unsubstituted fluorenyl group.

[0151] Embodiment 9: The method according to any one of Embodiments 1 to 8, wherein the metallocene is of formula (I-1), (I-2), (I-3), (I-4) or (I-5):

[0152] [Me2Si(Flu)2Nd(μ-BH4)2Li(THF)] (I-1)

[0153] [{Me2SiFlu2Nd(μ-BH4)2Li(THF)}2] (I-2)

[0154] [Me2SiFlu2Nd(μ-BH4)(THF)] (I-3)

[0155] [{Me2SiFlu2Nd(μ-BH4)(THF)}2] (I-4)

[0156] [Me2SiFlu2Nd(μ-BH4)] (I-5)

[0157] Where Flu represents C 13 H8 group.

[0158] Embodiment 10: A method according to any one of embodiments 1 to 9, wherein the organomagnesium reagent is of formula (IIa), (IIb), (IIc) or (IId), wherein R 3 , R 4 , R 5 and R B The same or different, indicating a carbon-based group, R A represents a divalent carbonyl group, X is a halogen atom, m is a number greater than or equal to 1, preferably equal to 1,

[0159] Mg 3 R 4 (IIa)

[0160] XOtM 5 (IIb)

[0161] R B -(Mg-R A ) m -Mg-R B (IIc)

[0162] X-Mg-R A -Mg-X (IId).

[0163] Embodiment 11: The method according to embodiment 10, wherein R A is a divalent aliphatic hydrocarbon chain, optionally interrupted by one or more oxygen or sulfur atoms or one or more arylene groups.

[0164] Embodiment 12: The method according to embodiment 10 or 11, wherein R A It is a branched or linear alkanediyl, cycloalkanediyl or xylenediyl group.

[0165] Embodiment 13: The method according to any one of Embodiments 10 to 12, wherein R A is an alkanediyl group containing 3 to 8 carbon atoms.

[0166] Embodiment 14: The method according to any one of Embodiments 10 to 13, wherein R B The invention comprises a benzene ring substituted by a magnesium atom, wherein one of the carbon atoms of the benzene ring at an ortho position to the magnesium is substituted by a methyl group, an ethyl group or an isopropyl group, or a ring is formed with the carbon atom most adjacent to the benzene ring and at a meta position to the magnesium, and another carbon atom of the benzene ring at an ortho position to the magnesium is substituted by a methyl group, an ethyl group or an isopropyl group.

[0167] Embodiment 15: The method according to embodiment 14, wherein R B It is 1,3-dimethylphenyl, 1,3-diethylphenyl, mesityl or 1,3,5-triethylphenyl.

[0168] Embodiment 16: The method according to embodiment 10, wherein R 3 A benzene ring substituted with a magnesium atom, one of the carbon atoms of the benzene ring ortho to the magnesium is substituted with a methyl group, an ethyl group, or an isopropyl group, or a ring is formed with the carbon atom closest to the benzene ring and meta to the magnesium, another carbon atom of the benzene ring ortho to the magnesium is substituted with a methyl group, an ethyl group, or an isopropyl group, and R 4 It is an alkyl group.

[0169] Embodiment 17: The method according to embodiment 16, wherein R 3 is 1,3-dimethylphenyl, 1,3-diethylphenyl, mesityl or 1,3,5-triethylphenyl, R 4 It is ethyl, butyl or octyl.

[0170] Embodiment 18: The method according to embodiment 10, wherein R 3 and R 4 is an alkyl group containing 2 to 10 carbon atoms.

[0171] Embodiment 19: The method according to embodiment 10, wherein R 5 is an alkyl group containing 2 to 10 carbon atoms.

[0172] Embodiment 20: The method according to any one of Embodiments 10 to 13 or 19, wherein X is a bromine atom or a chlorine atom.

[0173] Embodiment 21: The method according to any one of Embodiments 10 to 13 or 19 to 20, wherein the organomagnesium reagent is an organomagnesium halide, preferably formula (IIb) or (IId) as defined in Embodiment 10.

[0174] Embodiment 22: A method according to any one of Embodiments 10 to 13 or 19 to 21, wherein the organomagnesium reagent is of the formula XMgR 5 An organomagnesium halide, X is a chlorine atom or a bromine atom, R 5 is an alkyl group or an aryl group.

[0175] Embodiment 23: A method according to any one of Embodiments 10 to 13 or 19 to 22, wherein the organomagnesium reagent is of the formula XMgR 5 An organomagnesium halide, X is a chlorine atom or a bromine atom, R 5 is an alkyl group containing 2 to 10 carbon atoms.

[0176] Embodiment 24: A method according to any one of Embodiments 10 to 13 or 19 to 23, wherein the organomagnesium reagent is of the formula XMgR 5 An organomagnesium halide, X is a chlorine atom or a bromine atom, R 5 is ethyl, propyl, butyl, pentyl, hexyl, heptyl or octyl.

[0177] Embodiment 25: The method according to any one of Embodiments 1 to 24, wherein the compound containing a nitrile functional group contains a single nitrile functional group.

[0178] Embodiment 26: The method according to any one of embodiments 1 to 25, wherein the compound containing a nitrile functional group is a nitrile-substituted alkane, preferably containing 1 to 11 carbon atoms.

[0179] Embodiment 27: The method according to any one of Embodiments 1 to 25, wherein the compound containing a nitrile functional group is an aromatic hydrocarbon substituted with a nitrile functional group (preferably benzonitrile).

[0180] Embodiment 28: A method according to any one of Embodiments 1 to 25, wherein the compound containing a nitrile functional group is a compound containing a second functional group, and the second functional group is selected from ether, thioether, protected amine, tertiary amine, alkoxysilane and imidazole functional groups, preferably selected from ether functional groups, tertiary amine functional groups, alkoxysilane functional groups or imidazole functional groups.

[0181] Embodiment 29: A method according to any one of Embodiments 1 to 25, wherein the compound containing a nitrile functional group is an alkane substituted with a nitrile functional group and a functional group selected from ether, thioether, protected amine, tertiary amine and alkoxysilane functional group (preferably a tertiary amine functional group or an alkoxysilane functional group).

[0182] Embodiment 30: The method according to any one of Embodiments 1 to 25, wherein the compound containing a nitrile functional group is an aromatic hydrocarbon substituted with a nitrile functional group, preferably a substituted benzonitrile.

[0183] Embodiment 31: A method according to any one of Embodiments 1 to 25, wherein the compound containing a nitrile functional group is benzonitrile substituted with a functional group selected from ether, thioether, protected amine, tertiary amine and imidazole functional groups (preferably an ether functional group, a tertiary amine functional group or an imidazole functional group).

[0184] Embodiment 32: The method according to any one of Embodiments 1 to 31, wherein step b) is carried out with at least one molar equivalent of nitrile functional groups per mole of carbon-magnesium bonds of the organomagnesium reagent.

[0185] Embodiment 33: A polymer containing more than 50 mol% of ethylene units and carrying a ketone functional group and optionally a second functional group at one of its chain ends, wherein the second functional group is carried at the same chain end as the ketone functional group and is selected from ether, thioether, amine, alkoxysilane, silanol and imidazole functional groups, and the polymer is a copolymer of ethylene and 1,3-diene, or a copolymer of ethylene, 1,3-diene and a vinyl aromatic compound.

[0186] Embodiment 34: Polyethylene, which carries a keto functional group and a second functional group at one of its chain ends, the second functional group being carried at the same chain end as the keto functional group and being selected from ether, thioether, amine, alkoxysilane, silanol and imidazole functional groups. DETAILED DESCRIPTION

[0187] The above mentioned and other characteristics of the invention will be more clearly understood on reading the following description of an embodiment of the invention given by way of non-limiting illustration.

[0188] Example

[0189] Characterization of polymers:

[0190] High Temperature Size Exclusion Chromatography (HT-SEC) is used to characterize polyethylene:

[0191] High temperature size exclusion chromatography (HT-SEC) analysis was performed using a Viscotek machine (Malvern Instruments) equipped with three columns (PLgel Olexis 300 mm×7 mm ID from Agilent Technologies) and three detectors (differential refractometer, viscometer, and light scattering). -1 The concentration of 200 μl of elution in 1,2,4-trichlorobenzene is 8 mg.mL -1 The mobile phase was 2,6-di(tert-butyl)-4-methylphenol (400 mg.L -1) was stable. Data acquisition and analysis were performed using OmniSEC software. Standard polyethylene (M) from Polymer Standard Service (Mainz) was used. p :338, 507, 770, 1890, 17000, 27300, 43400, 53100, 65700, 78400g.mol -1 ) was used to calculate the number average molar mass (M) of the synthesized polyethylene. n ) and weight average molar mass (M w ).

[0192] Size Exclusion Chromatography (SEC-THF) was used to characterize ethylene / 1,3-butadiene copolymers:

[0193] Size exclusion chromatography was performed using a Viscotek machine (Malvern Instruments) equipped with three columns (SDVB from Polymer Standard Service, 5 μm, 300×7.5 mm), a guard column and three detectors (differential refractometer, viscometer and light scattering). 1 mL of 5 mg.mL THF was filtered through a 0.45 μm PTFE membrane. -1 At 35°C, use 0.8 mL / min -1 100 μL of this solution was eluted in THF at a flow rate of 1.5 %. Data acquisition and analysis were performed using OmniSEC software. Standard polystyrene (M) from Polymer Standard Service (Mainz) was used. p :1306g.mol -1 to 2520000g.mol -1 ) was used to calculate the number average molar mass (M) of the synthesized ethylene / 1,3-butadiene copolymer. n ) and weight average molar mass (M w ) and its dispersion

[0194] Nuclear Magnetic Resonance (NMR):

[0195] The spectrometer was operated on a Brüker 400Avance III spectrometer equipped with a 5 mm BBFO proton probe and at 400 MHz and a 10 mm PSEX 13C carbon probe and on a Brüker 400Avance II spectrometer operating at 400MHz, high-resolution NMR spectroscopy of polymers was performed. Ethylene homopolymers were collected at 363K in a mixture of tetrachloroethylene (TCE) and tritiated benzene (C6D6) (2 / 1 v / v), and ethylene / 1,3-butadiene copolymers were collected at 298K in tritiated chloroform (CDCl3). Samples were analyzed at a concentration of 1% by mass for protons and 5% by mass for carbon. Chemical shifts are given in ppm relative to the tritiated benzene proton signal set at 7.16ppm (or relative to the tritiated chloroform at 7.26ppm) and the TCE carbon signal set at 120.65ppm.

[0196] Preparation of polymer:

[0197] The metallocene [{Me2SiFlu2Nd(μ-BH4)2Li(THF)}]2 was prepared according to the procedure described in patent application WO 2007 / 054224.

[0198] Butyloctylmagnesium BOMAG (20% in heptane, 0.88 mol.L -1 ) was obtained from Chemtura and stored in a Schlenk tube under an inert atmosphere.

[0199] Magnesium halides were from Sigma-Aldrich unless otherwise stated.

[0200] N35 grade ethylene was obtained from the company Air Liquide and was used without prior purification.

[0201] Purification of 1,3-butadiene through an alumina protection tube. Purification of toluene and methylcyclohexane through an alumina protection tube.

[0202] 4-Methoxybenzonitrile was from Sigma-Aldrich.

[0203] In the procedures described, "cannulation" means the transfer is performed using a cannula.

[0204] Synthesis of functionalized polyethylene with chain-end ketones:

[0205] Embodiment PE1:

[0206] 198 ml of toluene from the solvent tank (SPS800 MBraun) was placed in a 250 mL inert round bottom flask equipped with an olive-shaped magnet. Under stirring, 2.0 mL of a 2.0 M solution of butyl magnesium chloride in diethyl ether was placed in the flask. Then 8.0 mg (12.5 μmol of neodymium) of {(Me2Si(C 13H8)2)Nd(μ-BH4)[(μ-BH4)Li(THF)]}2. Under an inert atmosphere, the catalytic solution is transferred to a 250 mL reactor by inserting a cannula. The pressure in the reactor is reduced to 0.5 bar, and then the reactor is pressurized to 4 bar with ethylene, while the temperature is raised to 80°C. The pressure in the reactor is kept constant by a tank filled with ethylene. When the required amount of ethylene has been consumed (in this case, after 15 minutes), the reactor is degassed, and 10 mL (5%) of the polymer solution is taken out of the reactor by inserting a cannula, and the polymer thus collected is precipitated from methanol, recovered by filtration, and vacuum dried at 80°C. It is named PE1NF.

[0207] To the remaining polymer solution in the reactor was added 10 mL of a 0.38 M degassed solution of benzonitrile in toluene stored on molecular sieves (3.8 mmol, 1 molar equivalent of nitrile functionality / carbon-magnesium bond). After stirring at 80° C. for 40 min, 3 ml of 15% aqueous hydrochloric acid was added to deactivate the system, and then the temperature was lowered to 20° C. The polymer solution was poured into methanol under stirring to precipitate the polymer. The precipitated polymer was filtered, washed with methanol, and then vacuum dried at 80° C. for characterization.

[0208] 4.68 g of the formula H-(CH2-CH2) was recovered. n -C(O)-(C6H5) polymer PE1F, and 0.21 g of H-(CH2-CH2) was recovered from the sample collected before the functionalization reaction. n The proton NMR spectrum of polymer PE1F (TCE / C6D6 2 / 1 v / v, 400 MHz, 363 K) showed that the proton at the α position to the ketone formed a triplet at δ = 2.70 ppm (triplet, CH3-(CH2-CH2) n -C H 2-C(O)-(C6H5)). The functional group content in polymer PE1F was calculated by normalizing the sum of the chain end signal integrals of the NMR spectrum (to 2). Thus, in PE1F, 93% of the polymer chain ends were functionalized with ketones. No by-products were identified by NMR.

[0209] Example PE2:

[0210] The synthesis of polymer PE2 was identical to that described in Example PE1, except that 2.0 mL of a 2.0 M solution of butylmagnesium chloride in diethyl ether was replaced by 2.0 mL of a 2.0 M solution of amylmagnesium bromide in diethyl ether.

[0211] 4.21 g of the formula H-(CH2-CH2) was recovered. n-C(O)-(C6H5) polymer PE2F, and 0.29 g of H-(CH2-CH2) was recovered from the sample collected before the functionalization reaction. n In PE2F, 89% of the polymer chain ends have been functionalized with ketones. No by-products were identified by NMR.

[0212] Embodiment PE3:

[0213] The synthesis of polymer PE3 was the same as described in Example PE1, except that 2.0 mL of a 2.0 M solution of butylmagnesium chloride in diethyl ether was replaced by 2.0 mL of a 2.0 M solution of amylmagnesium bromide in diethyl ether, a functionalization reaction was carried out by adding up to 3 molar equivalents of benzonitrile functional groups / carbon-magnesium bonds at the end of the polymerization, and a deactivation reaction was carried out after stirring at 80°C for 10 minutes.

[0214] 3.8 g of the formula H-(CH2-CH2) was recovered. n -C(O)-(C6H5) polymer PE3F, and 0.24 g of H-(CH2-CH2) was recovered from the sample collected before the functionalization reaction. n In PE3F, 93% of the polymer chain ends have been functionalized with ketones. No by-products were identified by NMR.

[0215] Embodiment PE4:

[0216] The synthesis of polymer PE4 was the same as described in Example PE1, except that 2.0 mL of a 2.0 M solution of butylmagnesium chloride in diethyl ether was replaced by 2.0 mL of a 2.0 M solution of amylmagnesium bromide in diethyl ether, functionalization was performed by adding a solution of benzonitrile (3 molar equivalents of nitrile functionality per carbon-magnesium bond) in 5 mL of methyltetrahydrofuran, and deactivation was performed after stirring at 80°C for 10 minutes.

[0217] 3.97 g of the formula H-(CH2-CH2) was recovered. n -C(O)-(C6H5) polymer PE4F, and 0.29 g of H-(CH2-CH2) was recovered from the sample collected before the functionalization reaction. n In PE4F, 88% of the polymer chain ends have been functionalized with ketones. No by-products were identified by NMR.

[0218] Example PE5:

[0219] The synthesis of polymer PE5 was the same as described in Example PE1, except that 2.0 mL of a 2.0 M solution of butylmagnesium chloride in diethyl ether was replaced by 2.0 mL of a 2.0 M solution of amylmagnesium bromide in diethyl ether, functionalization was performed by adding a solution of benzonitrile (3 molar equivalents of nitrile functionality per carbon-magnesium bond) in 5 mL of methyltetrahydrofuran, and deactivation was performed after stirring at 90°C for 10 minutes.

[0220] 4.35 g of the formula H-(CH2-CH2) was recovered. n -C(O)-(C6H5) polymer PE5F, and 0.20 g of H-(CH2-CH2) was recovered from the sample collected before the functionalization reaction. n In PE5F, 86% of the polymer chain ends have been functionalized with ketones. No by-products were identified by NMR.

[0221] Embodiment PE6:

[0222] The synthesis of polymer PE6 was the same as described in Example PE1, except that 2.0 mL of a 2.0 M solution of butylmagnesium chloride in diethyl ether was replaced by 2.5 mL of a solution of 1,5-di(magnesium bromide)pentanediyl (1.0 mmol, 5 mM in toluene) synthesized in methyltetrahydrofuran and then diluted to 0.4 M in toluene, and the functionalization reaction was carried out by adding 5 mL of a degassed 0.38 M solution of benzonitrile in toluene stored over molecular sieves (1.9 mmol, 1 molar equivalent of nitrile functionality per carbon-magnesium bond).

[0223] 3.83 g of the formula (C6H5)-C(O)-(CH2-CH2) was recovered n -C(O)-(C6H5)(telechelic polymer) or H-(CH2-CH2) n -C(O)-(C6H5) (monofunctional polymer) polymer PE6F, and 0.26 g of the formula H-(CH2-CH2) was recovered from the sample collected before the functionalization reaction. n In PE6F, 22% of the polymer chain ends are non-functionalized and 78% of the polymer chain ends have been functionalized with ketones, corresponding to 42% monofunctional chains and 18% telechelic chains. No by-products were identified by NMR.

[0224] 1,5-Bis(magnesium bromide)pentanediyl was prepared according to the following procedure:

[0225] 9.72 g of magnesium (400 mmol, 10 equiv), 80 mL of MeTHF (64 mL of which was in the dropping funnel), 60 mg of diiodine (0.23 mmol, 0.006 equiv), and 5.45 mL of 1,5-dibromopentane (40 mmol, 1 equiv) were used in the synthesis. Glassware used included a 200 mL flask and a 100 mL dropping funnel. Once the Grignard reagent synthesis was complete, the solution was transferred to a second 200 mL inertized flask via a filter cannula. The solution was concentrated under vacuum and then diluted in 55 mL of toluene. The concentration of pentanediyl groups was estimated to be 0.4 mol L -1 . This oil is immiscible with methylcyclohexane.

[0226] Aliquots of concentrated oil: 1 H NMR (toluene-D8-500 MHz-298K) δ: ppm=2.21 (quint, J=7.2 Hz, "b"), 1.88 (quint, J=7.0 Hz, "c"), 0.11 (t, J=7.4 Hz, "a"); quint is a quintet.

[0227]

[0228] Embodiment PE7:

[0229] The synthesis of polymer PE7 was the same as described in Example PE1, except that:

[0230] - 198 mL of toluene was replaced with 196 mL of toluene and 2 mL of diethyl ether,

[0231] - functionalization reaction was carried out by adding 10 mL of a 0.38 M degassed solution of 4-methoxybenzonitrile in toluene stored over molecular sieves (3.8 mmol, 1 molar equivalent of nitrile functionality per carbon-magnesium bond),

[0232] - After stirring at 80°C for 60 minutes, the deactivation reaction was carried out.

[0233] 4.17 g of the formula H-(CH2-CH2) was recovered. n -C(O)-(C6H4)-OCH3 polymer PE7F, and 0.23 g of the formula H-(CH2-CH2) was recovered from the sample collected before the functionalization reaction. n In PE7F, 89% of the polymer chain ends have been functionalized with ketones. No by-products were identified by NMR.

[0234] Example PE8:

[0235] The synthesis of polymer PE8 was the same as described in Example PE7, except that 2.0 mL of a 2.0 M solution of butylmagnesium chloride in diethyl ether was replaced with 2.0 mL of a 2.0 M solution of pentylmagnesium bromide in diethyl ether.

[0236] 4.27 g of the formula H-(CH2-CH2) was recovered. n -C(O)-(C6H4)-OCH3 polymer PE8F, and 0.16 g of the formula H-(CH2-CH2) was recovered from the sample collected before the functionalization reaction. n In PE8F, 82% of the polymer chain ends have been functionalized with ketones. No by-products were identified by NMR.

[0237] Example PE9:

[0238] The synthesis of polymer PE9 was the same as described in Example PE7, except that:

[0239] - Replace 196 mL of toluene with 194 mL of toluene,

[0240] - replace 2.0 mL of a 2.0 M solution of butylmagnesium chloride in diethyl ether with 4.0 mL of a 1.0 M solution of mesitylmagnesium bromide in diethyl ether,

[0241] - After the addition of the mesitylmagnesium bromide solution and before the introduction of the metallocene, 2.4 mL of a 1.6 M solution of n-butyllithium in hexane (3.84 mmol, 19.2 mM) were added,

[0242] - Before the functionalization reaction, 20 mL of polymer solution was collected instead of 10 mL,

[0243] - functionalization reaction was carried out by adding 18.5 mL of a degassed 0.38 M solution of 4-methoxybenzonitrile in toluene (7.0 mmol) stored over molecular sieves,

[0244] - After stirring at 80°C for 1 hour, a deactivation reaction was carried out, and the polymer solution was poured into methanol under stirring to precipitate the polymer.

[0245] 5.02 g of the formula H-(CH2-CH2) was recovered. n -C(O)-(C6H4)-OCH3 polymer PE9F, and 0.18 g of the formula H-(CH2-CH2) was recovered from the sample collected before the functionalization reaction. n In PE9F, 35% of the polymer chain ends are non-functionalized and 52% of the polymer chain ends have been functionalized with ketones.

[0246] Example PE10:

[0247] The synthesis of polymer PE10 was the same as described in Example PE7, except that:

[0248] - Replace 196 mL of toluene with 194 mL of toluene,

[0249] - Replace 2 mL of diethyl ether with 4 mL of diethyl ether,

[0250] - 2.0 mL of a 2.0 M solution of butylmagnesium chloride in diethyl ether was replaced with 2.27 mL of a 0.88 M solution of butyloctylmagnesium (BOMAG) in hexane,

[0251] - Functionalization was carried out by adding 10 mL of a degassed 0.38 M solution of 4-methoxybenzonitrile in toluene stored over molecular sieves (3.8 mmol, 1 molar equivalent of nitrile functionality per carbon-magnesium bond).

[0252] 4.55 g of the formula H-(CH2-CH2) was recovered. n -C(O)-(C6H4)-OCH3 polymer PE10F, and 0.18 g of H-(CH2-CH2) was recovered from the sample collected before the functionalization reaction. n In PE10F, 48% of the polymer chain ends are non-functionalized and 46% of the polymer chain ends have been functionalized with ketones.

[0253] Example PE11:

[0254] The synthesis of polymer PE11 was identical to that described in Example PE7, except that:

[0255] - 196 mL of toluene and 2 mL of diethyl ether were replaced with 198 mL of toluene,

[0256] - 2.0 mL of a 2.0 M solution of butylmagnesium chloride in diethyl ether was replaced with 2.27 mL of a 0.88 M solution of BOMAG in hexanes.

[0257] 3.65 g of the formula H-(CH2-CH2) was recovered. n -C(O)-(C6H4)-OCH3 polymer PE11F, and 0.24 g of the formula H-(CH2-CH2) was recovered from the sample collected before the functionalization reaction. n In PE11F, 44% of the polymer chain ends are non-functionalized and 49% of the polymer chain ends are functionalized with ketones.

[0258] Example PE12:

[0259] The synthesis of polymer PE12 was identical to that described in Example PE1, except that the functionalization reaction was carried out by adding 10 mL of a degassed 0.38 M solution of valeronitrile in toluene stored over molecular sieves (3.8 mmol, 1 molar equivalent of nitrile functionality per carbon-magnesium bond).

[0260] 4.48 g of the formula H-(CH2-CH2) was recovered. n -C(O)-(C4H9) polymer PE12F, and 0.27 g of H-(CH2-CH2) was recovered from the sample collected before the functionalization reaction. n -H polymer PE12NF. In PE12F, 2% of the polymer chain ends are non-functionalized and 98% of the polymer chain ends are ketone functionalized. No by-products were found by NMR.

[0261] Example PE13:

[0262] The synthesis of polymer PE13 was the same as described in Example PE1, except that:

[0263] - 2.0 mL of a 2.0 M solution of butylmagnesium chloride in diethyl ether was replaced with 2.27 mL of a 0.88 M solution of butyloctylmagnesium (BOMAG) in hexane.

[0264] - Functionalization reaction was carried out by adding 10 mL of a degassed 0.38 M solution of valeronitrile in toluene stored over molecular sieves (3.8 mmol, 1 molar equivalent of nitrile functionality per carbon-magnesium bond).

[0265] 3.59 g of the formula H-(CH2-CH2) was recovered. n -C(O)-(C4H9)-polymer PE13F, and 0.26 g of H-(CH2-CH2) ... n In PE13F, 51% of the polymer chain ends are non-functionalized and 43% of the polymer chain ends have been functionalized with ketones.

[0266] The polymerization conditions for ethylene are given in Table 1. Table 1 also shows the average catalytic activity for each example, in kg.mol -1 .h -1 The characteristics of the synthesized polyethylene are shown in Table 2.

[0267] Synthesis of functionalized ethylene / butadiene copolymers with chain-end ketones:

[0268] Example EBR1:

[0269] 199 ml of toluene from the solvent tank (SPS800 MBraun) was placed in a 250 mL inert round bottom flask equipped with an olive-shaped magnet. Under stirring, 1.0 mL of a 2.0 M solution of butyl magnesium chloride in diethyl ether was placed in the flask. Then 32.0 mg (50 μmol of neodymium) of {(Me2Si(C 13 H8)2)Nd(μ-BH4)[(μ-BH4)Li(THF)]}2. Under an inert atmosphere, the catalytic solution was transferred to a 250 mL reactor by inserting a cannula. The pressure in the reactor was reduced to 0.5 bar, and then the reactor was pressurized to 4 bar with an 80 / 20 mol / mol mixture of ethylene / butadiene, while the temperature was raised to 80°C. The pressure in the reactor was kept constant by a tank filled with an 80 / 20 mol / mol mixture of ethylene / butadiene gas. When the required amount of monomers was consumed (after 35 minutes in this case), the reactor was degassed and the temperature was reduced to 20°C. 10 mL (5%) of the polymer solution was taken out of the reactor by inserting a cannula, and the polymer was then precipitated from methanol containing 2,6-di-tert-butyl-4-methylphenol, washed with methanol, and then dried in vacuo at 80°C. It was named EBR1NF.

[0270] To the remaining polymer solution in the reactor was added 5 mL of a 0.38 M degassed solution of 4-methoxybenzonitrile in toluene (1.9 mmol, 1 molar equivalent of nitrile functionality per carbon-magnesium bond) stored on molecular sieves. After stirring at 80°C for 1 hour, 3 mL of 15% aqueous hydrochloric acid was added to deactivate the system. The polymer solution was poured into methanol under stirring to precipitate the polymer. The precipitated polymer was filtered, washed with methanol, and then dried under vacuum at 80°C for characterization.

[0271] Thus, 2.92 g of polymer EBR1F were recovered, and 0.17 g of polymer EBR1NF were recovered from the sample collected before the functionalization reaction. The proton NMR spectrum of polymer EBR1F (CDCl3, 400 MHz, 298 K) showed that the methylene protons in the α position to various ketones were formed at δ = 2.5-3.8 ppm, depending on the structure of the monomer unit constituting the polymer chain end (bound to the CO group of the ketone functional group), OC H 3 Protons and aromatic C(O)-C6 H 4-OCH3 protons. The number average molar mass was calculated by NMR assuming 100% functionalization. The functional group content in polymer EBR1F was calculated by dividing the molar mass determined by size exclusion chromatography by the molar mass calculated by NMR. Thus, in EBR1F, 49% of the polymer chain ends have been functionalized with ketones.

[0272] Example EBR2:

[0273] The synthesis of polymer EBR2 was the same as described in Example EBR1 except that:

[0274] - Replace 199 mL of toluene with 197 mL of toluene,

[0275] - replace 1.0 mL of a 2.0 M solution of butylmagnesium chloride in diethyl ether with 2.1 mL of a 1.0 M solution of mesitylmagnesium bromide in diethyl ether,

[0276] - Before the introduction of the metallocene, add 1.25 mL of a 1.6 M solution of n-butyl lithium in hexane (2.0 mmol, 10.0 mM),

[0277] - functionalization reaction was carried out by adding 10.25 mL of a degassed 0.38 M solution of 4-methoxybenzonitrile in toluene (3.9 mmol) stored over molecular sieves,

[0278] - After stirring at 80°C for 1 hour, a deactivation reaction was carried out, and the polymer solution was poured into methanol under stirring to precipitate the polymer.

[0279] 3.94 g of polymer EBR2F was recovered, and 0.17 g of polymer EBR2NF was recovered from the sample collected before the functionalization reaction. In EBR2F, 30% of the polymer chain ends had been functionalized with ketones.

[0280] Example EBR3:

[0281] The synthesis of polymer EBR3 was the same as described in Example EBR1 except that 1.0 mL of a 2.0 M solution of butylmagnesium chloride in diethyl ether was replaced with 1.14 mL of a 0.88 M solution of BOMAG in hexanes (1.0 mmol, 5 mM in a toluene / hexanes mixture).

[0282] 4.04 g of polymer EBR3F was recovered, and 0.20 g of polymer EBR3NF was recovered from a sample collected before the functionalization reaction. In EBR3F, 27% of the polymer chain ends had been functionalized with ketones.

[0283] Example EBR4:

[0284] The synthesis of polymer EBR4 was identical to that described in Example EBR1, except that butadiene was purified beforehand by condensation in a vial in the presence of trioctylaluminum.

[0285] 3.51 g of polymer EBR4F was recovered, and 0.19 g of polymer EBR4NF was recovered from the sample collected before the functionalization reaction. In EBR4F, 57% of the polymer chain ends had been functionalized with ketones.

[0286] Example EBR5:

[0287] The synthesis of polymer EBR5 was identical to that described in Example EBR4, except that the functionalization reaction was carried out by adding up to 3 molar equivalents of 4-methoxybenzonitrile functional groups per carbon-magnesium bond.

[0288] 3.4 g of polymer EBR5F was recovered, and 0.17 g of polymer EBR5NF was recovered from the sample collected before the functionalization reaction. In EBR5F, 62% of the polymer chain ends had been functionalized with ketones.

[0289] Example EBR6:

[0290] The synthesis of polymer EBR6 was the same as described in Example EBR1, except that:

[0291] - 199 mL of toluene was replaced with 280 mL of methylcyclohexane collected from the solvent tank (SPS800 MBraun),

[0292] - replace 1.0 mL of a 2.0 M solution of butylmagnesium chloride in diethyl ether with 0.125 mL of a 2.0 M solution of butylmagnesium chloride in diethyl ether,

[0293] - 32 mg of metallocene was replaced by 40.0 mg (62.5 μmol of neodymium) {(Me2Si(C 13 H8)2)Nd(μ-BH4)[(μ-BH4)Li(THF)]}2,

[0294] -Replace the 250ml reactor with a 500ml reactor,

[0295] - No sampling was done before the functionalization reaction,

[0296] - Functionalization was carried out by adding 10 mL of a degassed 0.025 M solution of 4-methoxybenzonitrile in methylcyclohexane stored over molecular sieves (0.25 mmol, 1 molar equivalent of nitrile functionality per carbon-magnesium bond).

[0297] 13.97 g of polymer EBR6F were recovered. 36% of the polymer chain ends had been functionalized with ketones.

[0298] Example EBR7:

[0299] The synthesis of polymer EBR7 was the same as described in Example EBR6, except that at the end of the polymerization, a functionalization reaction was carried out by adding 10 mL of a degassed 0.025 M solution of 4-dimethylaminobenzonitrile in methylcyclohexane stored over molecular sieves (0.25 mmol, 1 molar equivalent of nitrile functionality per carbon-magnesium bond).

[0300] 12.14 g of polymer EBR7F were recovered. 42% of the polymer chain ends had been functionalized with ketones.

[0301] The copolymerization conditions of ethylene and 1,3-butadiene are given in Table 3. Table 3 also shows the average catalytic activity of each example, in kg.mol -1 .h -1 The characteristics of the synthesized copolymers are shown in Tables 4 and 5. The molar mass of polymers EBR1 to EBR7 was determined using the SEC-THF method. The microstructure of the polymer was determined by NMR. The ethylene unit content, the content of 1,3-butadiene units of 1,2-configuration (1,2-unit), the content of 1,3-butadiene units of 1,4-configuration (1,4-unit) and the content of 1,2-cyclohexane units (cyclic units) are expressed as molar percentages relative to all monomer units of the polymer. The synthesized copolymers are statistical copolymers.

[0302] Table 1

[0303]

[0304]

[0305] Table 2

[0306]

[0307] *Measured by 1H NMR

[0308] Table 3

[0309]

[0310]

[0311] Table 4

[0312]

[0313] Table 5

[0314]

[0315]

[0316] Regardless of whether the polymer is polyethylene or an ethylene-rich diene copolymer, it can be observed that the process according to the invention does allow the synthesis of ethylene-rich polymers carrying keto functional groups at the chain ends.

[0317] It is also noted that the highest levels of chain-end keto functionality are obtained using organomagnesium halides such as butylmagnesium chloride and amylmagnesium bromide as cocatalysts. In the case of the synthesis of functionalized polyethylene, it is also noteworthy that the functionalization reaction is selective, since no by-products are formed.

[0318] It is also noteworthy that this method allows the simultaneous introduction of a keto functional group and a second functional group other than the keto functional group into the polymer (both located at the same chain end of the polymer) without resorting to the use of an additional functionalizing agent.

Claims

1. A process for preparing polymers which contain more than 50 mol % of ethylene units and which carry a keto function at one of their chain ends, The method comprises the consecutive steps a), b) and c): - step a) consists in polymerizing a monomer mixture containing ethylene in the presence of a catalytic system based on at least one metallocene of formula (I) and an organomagnesium reagent, {P(Cp 1 )(Cp 2 )Nd(BH4) (1+y)- L y -N x }(I) Cp 1 and Cp 2 are the same or different and are selected from fluorenyl, cyclopentadienyl and indenyl, which groups are substituted or unsubstituted, P is the bridge Cp 1 and Cp 2 Two groups and groups containing silicon atoms or carbon atoms, Nd represents a neodymium atom, L represents an alkali metal selected from lithium, sodium and potassium, N represents an ether molecule, X can be an integer greater than or equal to 0 or a non-integer, y is an integer greater than or equal to 0, - step b) is to react a compound containing a nitrile functional group with the product of the polymerization reaction of step a), - Step c) is a hydrolysis reaction, The polymer is polyethylene or a copolymer of ethylene with a 1,3-diene and optionally a vinyl aromatic compound.

2. The method according to claim 1, wherein: The monomer mixture is ethylene, a mixture of ethylene and 1,3-diene, or a mixture of ethylene, 1,3-diene and a vinyl aromatic compound, the vinyl aromatic compound preferably being styrene.

3. The method according to claim 1 or 2, wherein: The 1,3-diene monomer is 1,3-butadiene, isoprene, myrcene, β-farnesene or a mixture thereof.

4. The method according to any one of claims 1 to 3, wherein: Cp 1 and Cp 2 The same or different, is a substituted fluorenyl or a C 13 The unsubstituted fluorenyl group of H8 is preferably an unsubstituted fluorenyl group.

5. The method according to any one of claims 1 to 4, wherein: The organomagnesium reagent is of formula (IIa), (IIb), (IIc) or (IId), wherein R 3 , R 4 , R 5 and R B The same or different, indicating a carbon-based group, R A represents a divalent carbonyl group, X is a halogen atom, m is a number greater than or equal to 1, preferably equal to 1, MgR 3 R 4 (IIa) XMgR 5 (IIb) R B -(Mg-R A ) m -Mg-R B (IIc) X-Mg-R A -Mg-X(IId)。 6. The method according to any one of claims 1 to 5, wherein: The organomagnesium reagent is an organomagnesium halide, preferably a compound of formula (IIb) or (IId) as defined in claim 5.

7. The method according to any one of claims 1 to 6, wherein: The organomagnesium reagent is of the formula XMgR 5 An organomagnesium halide, X is a chlorine atom or a bromine atom, R 5 is an alkyl group or an aryl group.

8. The method according to any one of claims 1 to 7, wherein: The nitrile functional group containing compound contains a single nitrile functional group.

9. The method according to any one of claims 1 to 8, wherein: The compound containing a nitrile functional group is a compound containing a second functional group selected from ether, thioether, protected amine, tertiary amine, alkoxysilane and imidazole functional groups, preferably selected from ether functional groups, tertiary amine functional groups, alkoxysilane functional groups or imidazole functional groups.

10. The method according to any one of claims 1 to 9, wherein: The compound containing a nitrile functional group is an alkane substituted with a nitrile functional group and a functional group selected from the group consisting of ethers, thioethers, protected amines, tertiary amines and alkoxysilane functional groups, preferably tertiary amine functional groups or alkoxysilane functional groups.

11. The method according to any one of claims 1 to 9, wherein: The compound containing a nitrile functional group is an aromatic hydrocarbon substituted with a nitrile functional group, preferably a substituted benzonitrile.

12. The method according to any one of claims 1 to 9 or claim 11, wherein: The compound containing a nitrile functional group is benzonitrile substituted with a functional group selected from the group consisting of an ether, a thioether, a protected amine, a tertiary amine and an imidazole functional group, preferably an ether functional group, a tertiary amine functional group or an imidazole functional group.

13. A polymer containing more than 50 mol % of ethylene units and carrying at one of its chain ends a keto function and optionally a second functional group, which is carried at the same chain end as the keto function and is chosen from ether, thioether, amine, alkoxysilane, silanol and imidazole functional groups, said polymer being a copolymer of ethylene and 1,3-diene or a copolymer of ethylene, 1,3-diene and a vinyl aromatic compound.

14. Polyethylene carrying at one of its chain ends a keto functional group and a second functional group, which is carried at the same chain end as the keto functional group and is chosen from ether, thioether, amine, alkoxysilane, silanol and imidazole functional groups.

Images