EP3083731A1

EP3083731A1 - Method for synthesising a diene polymer functionalised by pendant epoxide groups along the chain

Info

Publication number: EP3083731A1
Application number: EP14808613.5A
Authority: EP
Inventors: Rachid Matmour
Original assignee: Michelin Recherche et Technique SA Switzerland; Compagnie Generale des Etablissements Michelin SCA; Michelin Recherche et Technique SA France
Current assignee: Compagnie Generale des Etablissements Michelin SCA
Priority date: 2013-12-19
Filing date: 2014-12-05
Publication date: 2016-10-26
Also published as: US20160319061A1; FR3015488B1; FR3015488A1; WO2015091020A1; US10179827B2

Abstract

The present invention relates to a method for synthesising a modified polymer including epoxide groups along the polymer chain by causing the hydrosilylation reaction of the unsaturations with a hydrogenosilane having an epoxide function in the presence of a suitable catalyst. The method according to the invention is simple, reproducible and capable of being used on an industrial scale, and makes it possible to achieve high grafting yields of up to 100 %.

Description

Process for the synthesis of a functionalized diene polymer with pendant epoxide groups along the chain

The present invention relates to a process for synthesizing a modified polymer comprising epoxy groups along the polymer chain. More particularly, the present invention relates to obtaining these epoxidized polymers by functionalization of an unsaturated diene polymer. The invention also relates to the functional polymer obtained and the crosslinkable composition containing it. Polymers carrying epoxide functions are widely used for the reactivity of the epoxide function in various applications. They are mainly used in industry fields using elastomers that need to be cross-linked in some other way than via sulfur.

The epoxide function can be carried directly by the carbon skeleton of the diene polymer, and is then mainly obtained by epoxidation of carbon-carbon double bonds initially present after copolymerization. This epoxidation of unsaturated polymers is well known to those skilled in the art, and can be carried out, for example, by chlorohydrin or bromohydrin-based processes, direct oxidation processes or hydrogen peroxide-based processes. alkyl hydroperoxides or peracids (such as peracetic acid or performic acid).

The epoxide function may also be pendant and is then either already present in a monomer involved in the copolymerization with the other monomer (s) constituting the polymer (this monomer may be, for example, glycidyl methacrylate, allyl glycidyl ether or glycidyl ether) ,. The use of a monomer already comprising the epoxide function for the synthesis of the epoxidized polymer, requires specific operating conditions of copolymerization which limit the flexibility of the synthesis process. Indeed, certain syntheses require very high pressures for radical phase copolymerizations of copolymers based on glycidyl methacrylate, for example terpolymers of ethylene, vinyl acetate and glycidyl (meth) acrylate (commercial products). LOTADER AX8840® and AX8900® and Arkema patent EP0599684A1). Moreover, it is known to those skilled in the art that the polar functions, such as glycidyl functions, can act as a poison of catalytic complexes used for the polymerization of monomers by coordination-insertion. The technical problem that arises with respect to the state of the art is to provide a method for synthesizing a polymer carrying epoxy functions along the chain in a simple and controlled manner with productivity in line with a production. industrial. Continuing their research, the inventors have now developed a new process for synthesizing a polymer bearing pendant epoxide functional groups along the chain by grafting a hydrogenosilane carrying an epoxide function on the unsaturations of the polymer by reaction. hydrosilylation. The grafting yield is high since it can reach 100% on unsaturations. The process according to the invention is simple, reproducible and capable of being used on an industrial scale.

Patent applications WO2003085024A1, JP4586966B2, JP2006002035A, JP07133347A and JP05339504A, report the use of hydrogenosilanes to introduce an epoxy end-chain function of vinyl or allyl terminated polymers. Thus, after polymerization, functions are terminated at the end of the polymer chain by hydrosilylation using functional epoxy hydrogenosilanes. In WO2003085024A1, the authors are interested in the functionalization of polyisobutylene terminated allyl. In JP4586966B2 and JP2006002035A, the authors are interested in the functionalization of fluorinated polyethers and vinyl-terminated polyimides. In JP07133347A, the authors are interested in the functionalization of vinyl-terminated polysiloxanes. In JP05339504A, the authors are interested in the functionalization of aromatic polyether terminated allyl. These modifications by hydrosilylation require that the polymer is exclusively non-diene and end-functionalized in end by an allylic or vinylic group. In addition, it is not a question of synthesizing polymers carrying epoxide functions along the chain.

Accordingly, a first object of the invention relates to a process for synthesizing a diene polymer comprising epoxide functions along the chain, characterized in that it comprises the step of modifying an unsaturated polymer comprising unsaturations. along the chain by hydrosilylation, by reacting the unsaturated polymer with an epoxidized hydrogenosilane of formula 1 in the presence of a catalyst

Formula I

with R and R _2, identical or different, each being an alkyl group C 1 -C 5, C ₆ -C _4, aromatic C ₇ -Cn alkyl;

R ₃ , R ₄ and R ₅ , which may be identical or different, each being a hydrogen atom or a C ₁ -C ₅ alkyl, C ₆ -C ₄ aryl or C ₇ aromatic alkyl group;

Y is a bridging group with a valence equal to i + 1; and i is an integer of from 1 to 3.

Another subject of the invention is the diene polymer comprising epoxide functional groups along the chain that can be obtained by the method which is also the subject of the invention.

The subject of the invention is also a rubber composition comprising such a polymer.

In the present description, any range of values designated by the expression "between a and b" represents the range of values from more than a to less than b (i.e., terminals a and b excluded) while any range of values designated by the term "from a to b" means the range from a to b (i.e., including the strict limits a and b).

In the present description, when reference is made to a "majority" compound, it is understood in the sense of the present invention that this compound is predominant among the compounds of the same type in the composition, that is to say that is the one which represents the largest quantity by mass among the compounds of the same type. Thus, for example, a majority elastomer is the elastomer representing the largest mass relative to the total mass of the elastomers in the composition. In the same way, a so-called majority charge is that representing the largest mass among the charges of the composition. For example, in a system comprising a single elastomer, it is the majority within the meaning of the present invention; and in a system comprising two elastomers, the majority elastomer represents more than half of the mass of the elastomers. In contrast, a "minor" compound is a compound that does not represent the largest mass fraction among compounds of the same type.

In the present description, by the term "along the chain" with reference to a pendant group of the polymer or unsaturation, it is meant that the polymer includes pendant groups of this type or unsaturations at several points in the chain. This includes the end or ends of the chain but is not limited to these locations. When a group or unsaturation is present in at least one chain end, the polymer also comprises at least one other pendant group of this type or another unsaturation at another position in the chain.

In the present description, the term "graft" means the lateral group attached to the main chain of the polymer from the hydrosilylation grafting of the epoxidized hydrogenosilane. The terms "epoxidized", "epoxy functional" or "epoxy functional" are used in the present description as interchangeable equivalent expressions.

Thus, a first object of the invention is a process for synthesizing a diene polymer comprising pendant epoxide functions along the chain of modifying a polymer comprising unsaturations along the chain by a hydrosilylation reaction in the presence an epoxidized hydrogenosilane of formula I and a catalyst.

The invention comprises the distinct but combinable variants which follow concerning the nature of the hydrogenosilane of formula I.

In formula I, when Rx denotes an alkyl radical, it has 1 to 5 carbon atoms, preferably 1 to 4, more preferably 1 to 3 carbon atoms. By way of example, mention may be made of methyl, ethyl and propyl radicals.

In formula I, when R 1 represents an aryl radical, it has 6 to 14 carbon atoms. By way of example, mention may be made of phenyl, naphthyl and anthracenyl radicals.

In formula I, when Rx is an alkyl aromatic radical, it has 7 to 11 carbon atoms. By way of example, mention may be made of benzyl, tolyl and xylyl radicals.

According to variants, in formula I, R ₃ , R ₄ and R ₅ are preferably identical and represent a hydrogen atom.

According to other variants, in formula I, R 1 and R ₂ , which may be identical or different, preferably denote a C 1 -C ₅ alkyl group. According to other variants further, in formula I, Y preferably represents a hydrocarbon chain, linear, branched, cyclic, which may contain one or more aromatic radicals, and / or one or more heteroatoms, such as, for example, N, O or Si. According to a preferred embodiment, the bridging group Y is a linear or branched C1-C24, preferably C1-C10, alkyl chain, optionally interrupted by one or more silicon and / or oxygen atoms. More preferably, Y is a linear C ₁ -C ₆ alkyl chain interrupted by one or more silicon and / or oxygen atoms. When the hydrocarbon chain Y comprises at least one silicon atom, it may be substituted preferably by at least one C 1 -C 4 alkyl radical, preferably methyl or ethyl. When the hydrocarbon chain Y comprises at least one oxygen atom, it is preferably separated from the epoxy group by a methylene group.

In formula I, i is preferably 1.

According to particularly advantageous variants, the epoxidized hydrogenosilane that can be used in the context of the process of the invention has at least one of the following four characteristics, preferably the four: R 1 and R ₂ , which are identical or different, denote an alkyl radical C1-C5, preferably methyl and ethyl,

R ₃ , R ₄ and R ₅ are identical and represent a hydrogen atom,

Y is a linear C ₁ -C ₆ alkyl chain interrupted by at least one oxygen atom separated from the epoxy group by a methylene group and by at least one silicon atom substituted with two identical or different alkyl radicals, in d-C ₅ preferably methyl and ethyl,

i is 1.

Silanes such as, for example, (3-glycidoxypropyl) -1,1,3,3-tetramethyldisiloxane (Formula A), may be used as molecules for grafting within the context of the invention. Dioxa-2,4-disilaoctane 2,4,4-trimethyl-8- (2-oxiranyl) (Formula B), 2,7-Dioxa-6,8-disiladecane 6-ethyl-6,8-dimethyl-1 - (2-oxiranyl) (Formula C), etc. Me 2

Me

Formula A Me 2

Me

Formula B

Me

o SÎH- And

THE

CH ₂ O (CH 2) ₃ - Si - And

Me

Form C

Among the functional epoxy functional hydrogenosilane derivatives that may be used in the context of the invention, some may be found commercially, such as, for example, the compound of formula A commercially available from ABCR or Gelest.

Thus, according to the invention, the hydrogenosilane described above reacts by hydrosilylation with the unsaturations of an unsaturated diene polymer.

By diene polymer, should be understood according to the invention any polymer derived at least in part (i.e., a homopolymer or a copolymer) of monomers dienes (monomers bearing two carbon-carbon double bonds, conjugated or not). The diene polymer according to the invention comprises unsaturations of the carbon-carbon double bond type. The polymer according to the invention preferably has between unsaturations, unsaturations hanging along the chain. According to certain variants, these pendant unsaturation are so-called unsaturations of vinyl origin. Unsaturations of vinyl origin are termed pendant unsaturation of the polymer chain from a vinyl type insertion of the diene monomer into the polymer. By way of examples of unsaturations of vinyl origin, mention may be made of those resulting from a type 1 insertion, 2 for example butadiene, isoprene or any other diene having a C1 unsaturation, or else type 3,4- inserts of isoprene for example ...

The unsaturated polymer according to the invention may belong to any category of diene polymers derived at least in part from diene monomers, conjugated or otherwise. It is any type of polymer in the sense known to those skilled in the art, whether of a thermoplastic or elastomeric nature, provided that this polymer is unsaturated. Preferably, the unsaturated diene polymer is chosen from diene elastomers. The unsaturated diene polymer according to the invention comprises unsaturations along the chain. The mass ratio of the monomeric units carrying these unsaturations varies in a wide range which makes it possible to encompass the different categories of polymers. Thus, the diene polymers suitable for being used in the process of the invention may be weakly unsaturated with a mass content of unsaturated monomeric units of at least 1% relative to the total weight of the polymer. According to variants this rate can then be at least 5% by weight, or even at least 10% by weight. The diene polymers suitable for use in the process of the invention may also be highly unsaturated, with a mass ratio of unsaturated monomeric units greater than 20% and up to 100% based on the total weight of the polymer. According to some variants, this rate can then be at least 40% and even at least 50%. When the mass ratio of unsaturated monomeric units is less than 1%, the intended technical effect of the epoxidized polymer may be insufficient.

According to preferred embodiments, any diene polymer comprising at least unsaturated units, part of which is derived from an insertion of the conjugated or non-conjugated diene monomer, leading to a pendant unsaturation, in particular according to some of these variants, is suitable according to the invention. any diene polymer comprising at least unsaturated units, part of which is derived from a vinyl insertion.

The term "diene polymer" that may be used in the invention is more particularly understood to mean a diene polymer corresponding to one of the following categories:

(a) any homopolymer obtained by polymerization of a conjugated diene monomer having from 4 to 12 carbon atoms;

(b) any copolymer obtained by copolymerization of one or more of the conjugated dienes mentioned above, with one another or with one or more ethylenically unsaturated monomers;

(c) any homopolymer obtained by polymerization of a non-conjugated diene monomer having 5 to 12 carbon atoms; (d) any copolymer obtained by copolymerization of one or more of the aforementioned non-conjugated dienes with each other or with one or more ethylenically unsaturated monomers;

(e) a ternary copolymer obtained by copolymerization of ethylene, an oolefin having 3 to 6 carbon atoms with a non-conjugated diene monomer having from 6 to 12 carbon atoms, for example elastomers obtained from ethylene propylene with a non-conjugated diene monomer as described in particular in the documents WO 2004 / 035639A1 and US 2005 / 0239639A1;

(f) a copolymer of isobutene and isoprene (butyl rubber), as well as the halogenated, in particular chlorinated or brominated, versions of this type of copolymer;

(g) natural rubber;

(h) an unsaturated olefinic copolymer whose chain comprises at least olefinic monomeric units, ie units resulting from the insertion of at least one mono-olefin, and diene units derived from at least one diene conjugate. (i) a mixture of several of the elastomers defined in (a) to (h) between them.

As suitable conjugated diene monomer for the synthesis of polymers (a), (b) and (h), 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-butadiene and di (C 1 -C 5) -alkyl-1,3-butadienes such as, for example, 2,3-dimethyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2-methyl-3 ethyl-1,3-butadiene, 2-methyl-3-isopropyl-1,3-butadiene, aryl-1,3-butadiene, 1,3-pentadiene, 2,4-hexadiene.

As non-conjugated diene monomer suitable for the synthesis of polymers (c), (d) and (e), mention may be made of pentadiene-1,4, hexadiene-1,4, ethylidene norbornene, dicyclopentadiene ;

As ethylenically unsaturated monomers capable of intervening in the copolymerization with one or more diene monomers, conjugated or otherwise, to synthesize the copolymers (b) or (d), mention may be made of:

vinylaromatic compounds having 8 to 20 carbon atoms, for example styrene, ortho-, meta-, para-methylstyrene, the commercial mixture vinylmesitylene, divinylbenzene, vinylnaphthalene; vinyl nitrile monomers having 3 to 12 carbon atoms, for example acrylonitrile or methacrylonitrile; acrylic ester monomers derived from acrylic acid or methacrylic acid with alcohols having 1 to 12 carbon atoms, for example methyl acrylate, ethyl acrylate or propyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate;

The copolymers (b) or (d) may contain between 99% and 1% by weight of diene units and between 1% and 99% by weight of vinylaromatic units, vinyl nitriles and / or acrylic esters. As a mono-olefin monomer suitable for the synthesis of the polymers (h), mention may be made of ethylene, an oolefin having 3 to 6 carbon atoms, for example propylene. Preferably, the mono-olefin monomer is ethylene.

According to certain variants, the olefinic copolymer (h) that can be used in the process of the invention is a copolymer whose chain comprises olefinic monomeric units, that is to say units resulting from the insertion of less a mono-olefin, and diene units derived from at least one conjugated diene. According to other variants, the units are not integrally units derived from diene monomers and monoolefinic monomers. According to these variants, other units resulting for example from an ethylenically unsaturated monomer as described above, are present in the carbon chain.

According to certain variants, the olefinic monomeric units in the polymer (h) are in the majority, more preferably, the molar level of these units is greater than 50% relative to the polymer. Among these variants, the molar rate can be at least 65% and at most 95%, or even at most 85%. Such elastomers and their synthetic processes are described in applications EP 1 092 731, EP 1 554 321, EP 1 656 400, EP 1 954 705, EP 1 957 506 and FR 13/50557 in the name of the Applicants.

Among the diene polymers derived from at least one conjugated diene monomer used in the context of the modification process according to the invention, non-exclusive examples that may be mentioned include polybutadiene, polyisoprene, polychloroprene and their hydrogenated versions, polyisobutylene. , block copolymers of butadiene and isoprene with styrene, and their hydrogenated versions such as poly styrene-b-butadiene (SB), poly styrene-b-butadiene-b-styrene (SBS), poly styrene-b-isoprene-b-styrene (SIS), poly styrene-b- (isoprene-st-butadiene) -b-styrene or poly styrene-b-isoprene-b-butadiene-b-styrene (SIBS), SBS hydrogen (SEBS), poly styrene-b- butadiene-b-methyl methacrylate (SBM), as well as its hydrogenated version (SEBM), the random copolymers of butadiene with styrene (SBR) and acrylonitrile (NBR) and their hydrogenated versions, the random copolymers of isoprene with styrene (SIR) and their hydrogenated versions, random copolymers of isoprene and butadiene with styrene (SBIR) and their hydrogenated versions, butyl or halogenated rubbers, ethylene-propylene-diene terpolymers (EPDM), ethylene-diene copolymers and mixtures thereof.

Among these, the diene polymer (s) used in the invention are very particularly chosen from the group of diene polymers consisting of polybutadienes (abbreviated as "BR"), synthetic polyisoprenes (IR) and natural rubber (NR). ), butadiene copolymers, isoprene copolymers, ethylene-diene copolymers and mixtures of these polymers. Such copolymers are more preferably selected from the group consisting of butadiene-styrene copolymers (SBR), isoprene-butadiene copolymers (BIR), isoprene-styrene copolymers (SIR), isoprene-copolymers of butadiene-styrene (SBIR) and ethylene-butadiene copolymers (EBR).

The polymers that can be used according to the invention can be obtained according to conventional polymerization techniques well known to those skilled in the art. The polymers may have any microstructure which is a function of the polymerization conditions used, in particular the presence or absence of a modifying and / or randomizing agent and their quantity. The polymers may be, for example, block, random, sequenced or microsequential, and may be prepared in dispersion, in emulsion or in solution; they can be coupled and / or starred or further functionalized with a suitable functionalization agent. Prior to the hydrosilylation grafting reaction according to the invention, the process comprises dissolving in an apolar solvent at least one unsaturated diene polymer, an epoxy functional hydrogenosilane and a hydrosilylation catalyst. This solubilization can be done according to any implementation at the disposal of the skilled person. According to one embodiment, the unsaturated polymer, the epoxy functional hydrogenosilane and the catalyst are dissolved in the apolar solvent with stirring.

As an apolar solvent, any inert hydrocarbon solvent which may be, for example, an aliphatic or alicyclic hydrocarbon such as pentane, hexane, heptane, isooctane, hexane, hexane, isooctane or octane, may be used according to the process according to the invention. cyclohexane, methylcyclohexane or an aromatic hydrocarbon such as benzene, toluene, xylene, and mixtures thereof. Preferably, methylcyclohexane or toluene is used.

By way of catalyst, it is possible to use according to the invention any known catalyst for the catalysis of hydrosilylation based on transition metals generally of group VIII such as platinum, palladium, rhodium, ruthenium, iron, Among these different catalysts used for the hydrosilylation reaction, platinum-based catalysts such as hexachloroplatinic acid hexahydrate (Speier catalyst) and platinum-1,1,3,3-catalyst will preferably be selected. 1-tetramethyl-1,3-divinylsiloxane (Karstedt catalyst) and more preferably the Karstedt catalyst. The catalyst may be added to the reaction mixture in any customary form, however, preferably in the form of a solution in a solvent.

Preferably, the amount of total solvent, or solvent of the reaction medium, is such that the mass concentration of polymer is between 1 and 40% by weight, preferably between 2 and 20% and even more preferably between 2 and 10%. in said solvent. By total solvent, or solvent of the reaction medium, is meant all the solvents used to solubilize the unsaturated polymer, the epoxy functional hydrogenosilane and the hydrosilylation catalyst.

The process according to the invention may advantageously comprise a step of heating the homogeneous reaction mixture obtained in the preceding step to the temperature of the grafting reaction. The grafting reaction temperature is at least 20 ° C and at most 120 ° C, preferably it is at least 50 ° C, or even at least 60 ° C and at most 100 ° C, or at most 90 ° C .

The degree of grafting can be adjusted in a manner known to those skilled in the art, by varying different operating conditions, such as in particular the amount of molecules to be grafted, the temperature or the reaction time. It is possible to achieve quantitative grafting yields.

Thus, the degree of grafting is preferably at least 0.1 mol% of grafts relative to the modified polymer. The degree of grafting is preferably at most 50 mol% of grafts relative to the modified polymer, and according to some variants the degree of grafting is less than 20 mol% of grafts relative to the modified polymer.

It should be noted that in the context of the invention the variants and the preferred aspects described above are combinable with each other. According to the invention, the grafting method thus defined makes it possible to achieve significantly high grafting yields, ranging from 30% to 100%, or, depending on particular implementations, yields ranging from 70% to 100%, or even even from 80% to 100%, and this in relatively short times especially with respect to an epoxidation reaction. Indeed, according to some variants, the reaction times can be divided by at least 10.

The process of the invention makes it possible to synthesize a diene polymer comprising epoxide functions along the chain. This polymer is also the subject of the invention. This diene polymer comprises units (i.e. at least two of which at least one is located in the chain as opposed to the end position of the chain) carrying a pendant epoxide function along the chain and bonded to those by means of a silicon atom.

More particularly, these epoxidized units carry a pendant epoxide function along the chain corresponding to formula 2

Formula 2 with

R _1, R _2, R ₄ and R ₅ , as well as Y and i are as defined above, including the advantageous or preferred variants.

* denotes a point of connection with the polymer chain.

Thus, according to certain particularly advantageous variants, these epoxidized units carry a pendant epoxide function along the chain according to one of the following formulas AB 'and C:

^* designating in each of these formulas a point of connection with the polymer chain.

According to variants of the invention, the epoxidized diene polymer comprises units carrying a pendant epoxide function along the chain and bonded thereto via a silicon atom in a molar ratio of at least 0 , 1% and not more than 50%. For some applications, this level is preferably at most 20%, more preferably at most 10% molar. The epoxidized diene polymer according to the invention therefore comprises non-epoxidized units at a molar ratio of at most 99.9%. According to certain applications, this level of non-epoxidized units is preferably at least 80 mol%. The molar levels are measured relative to the totality of the polymer.

In the case where the units present in the carbon chain comprise non-epoxidized units, several distinct variants that are combinable with each other are conceivable.

Thus, according to variants of the invention, these non-epoxidized units comprise units derived from at least one diene monomer, conjugated or otherwise, as described above. As particular conjugated diene monomer, mention may be made of butadiene and isoprene

According to other variants, these non-epoxidized units comprise units that may be derived from at least one monoolefin as described above. As such, there may be mentioned ethylene, propylene, butylene, isobutylene, more particularly ethylene. In still other embodiments, the non-epoxidized units comprise units derived from at least one ethylenically unsaturated monomer. As such, there may be mentioned vinylaromatic monomers having from 8 to 20 carbon atoms, vinyl nitrile monomers having 3 to 12 carbon atoms and acrylic ester monomers derived from acrylic acid or methacrylic acid with an alcohol having 1 to 12 carbon atoms as described above. As such can be mentioned more particularly styrene.

Another object of the invention is a crosslinkable rubber composition comprising this epoxy functional polymer as described above or prepared by hydrolysis according to the method described above.

The diene polymers grafted according to the process of the invention can be used as such or in mixtures with one or more other compounds. The presence of epoxide groups grafted along the chain makes it possible to envisage the use in similar applications of diene polymers functionalized with these same epoxide groups.

For example, it is known for the optimization of the interactions between the elastomer and the reinforcing filler within a reinforced rubber composition, to modify the nature of the diene elastomers in order to introduce functional groups therein. Thus, the particular structure of the graft polymer according to the invention makes it possible to envisage its use in the manufacture of various products based on reinforced rubber depending on the nature of the grafted epoxidized hydrogenosilane derivative.

It is also known that the epoxide groups have a very particular reactivity with certain compounds. It is thus possible to envisage a use of the graft polymer according to the invention in applications where such reactivity is necessary.

In the field of tires, especially for vehicles, the uses mentioned above are possible. Therefore, a tire of which one of these components comprises a rubber composition based on an epoxidized diene polymer described above by its structure or its method of synthesis, is also an object of the invention.

The aforementioned features of the present invention, as well as others, will be better understood on reading the following description of several embodiments of the invention, given by way of illustration and not limitation. EXAMPLE OF CARRYING OUT THE INVENTION

Measures used

The elastomers are characterized, before cooking, as indicated below. Ch romatograph of steric excl u sity

Size Exclusion Chromatography (SEC) is used. The SEC makes it possible to separate the macromolecules in solution according to their size through columns filled with a porous gel. The macromolecules are separated according to their hydrodynamic volume, the larger ones being eluted first.

Without being an absolute method, the SEC allows to apprehend the distribution of the molar masses of a polymer. From commercial standard products, the various average molar masses (Mn) and weight (Mw) can be determined and the polymolecularity index or polydispersity (Ip = Mw / Mn) calculated via a calibration called MOORE.

Preparation of the polymer: There is no particular treatment of the polymer sample before analysis. This is simply solubilized in (tetrahydrofuran + 1% vol of distilled water) at a concentration of about 1 g / l. Then the solution is filtered on 0.45μηΊ porosity filter before injection. SEC analysis: The equipment used is a "WATERS alliance" chromatograph. The elution solvent is tetrahydrofuran. The flow rate is 0.7 ml / min, the system temperature 35 ° C and the analysis time 90 min. A set of four WATERS columns in series, trade names "STYRAGEL HMW7", "STYRAGEL HMW6E" and two "STYRAGEL HT6E" are used. The injected volume of the solution of the polymer sample is 100 μl. The detector is a differential refractometer "WATERS 2410" and the chromatographic data exploitation software is the "WATERS EMPOWER" system.

The average molar masses calculated relate to a calibration curve made from commercial standard polystyrene "PSS READY CAL-KIT". Tem of tra ns ition vitreu

The glass transition temperatures Tg of the polymers are measured by means of a differential scanning calorimeter. The analysis is performed according to the requirements of ASTM D3418-08.

S pectroscopy of reson n ce m a n e o ry

Determinations of the levels of the different monomer units and their microstructures within the copolymer are carried out by NMR analysis. The spectra are acquired on a BRUKER 500 MHz spectrometer equipped with a BBIz-grad 5 mm Broad Band probe. Experience quantitative NMR ¹ H, uses a simple pulse sequence 30 ° and a repeating time of 5 seconds between each acquisition. The samples are solubilized in CDCI ₃ .

Exem plementation of the invention

Starting polymers used:

SBR1 copolymer of butadiene and styrene prepared in solution having the following microstructure characteristics by ¹ H NMR:

Mass ratio of 1, 2- (vinyl) units / PB: 24.2%

Mass ratio of styrene / SBR units: 27.8%

This polymer has a molecular weight Mn = 1 18 300 g / mol and an Ip = 1, 07 and a Tg of -47 ° C (with ΔΤ = 7). SBR2 copolymer of butadiene and styrene prepared in solution having the following microstructure characteristics by ¹ H NMR:

Mass ratio of units 1, 2 - (vinyl) / PB: 58.7%

Mass ratio of styrene / SBR units: 27.2%

This polymer has a molecular weight Mn = 120348 g / mol, a lp = 1, 89 and a Tg of -23.8 ° C (with ΔΤ = 6). Copolymer EBR1 of butadiene and ethylene prepared in solution according to patent EP 1 954 705 B1, exhibiting the following microstructure characteristics by ¹ H NMR:

mass ratio of ethylene units: 51.6%

mass ratio of 1, 2- (vinyl) units: 41, 9%

mass ratio of motifs 1, 4: 22%

mass ratio of cyclic units: 36.1%

This copolymer has a molecular weight Mn = 141744 g / mol and an Ip = 1.65 and a Tg of -44.2 ° C (with ΔΤ = 5).

Treatment applied to this starting elastomer:

The starting polymer is subjected to an antioxidant treatment by the addition of 0.4 parts per hundred parts of elastomers (phr) of 4,4'-methylene-bis-2,6-tert-butylphenol and 0.4 parts by weight. one hundred parts elastomers (phr) of N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine.

Epoxy functional silicone used:

-Glycidoxypropyl) -1,1,3,3-tetramethyldisiloxane of formula:

Example 1 2 g of SBR1 are dissolved in 100 ml of toluene in a 250 ml reactor equipped with mechanical stirring. 4.05 mmol (1 g) of (3-glycidoxypropyl) - 1, 1, 3,3-tetramethyldisiloxane and _200, uL of platinum-1, 1, 3,3-tetramethyl-1, 3- divinylsiloxane in solution in xylene (Karstedt catalyst) (CAS No. 68478-92-2) are added to the polymer solution and the reaction medium is heated to 60 ° C.

After 2 hours at 60 ° C with stirring, the reaction medium is allowed to return to room temperature. Once it has returned to ambient temperature, the reaction medium is then coagulated in 250 ml of methanol and then rinsed with 250 ml of methanol.

The solution polymer then undergoes an antioxidant treatment of 0.4 parts per hundred parts elastomers (phr) of 4,4'-methylene-bis-2,6-tert-butylphenol and 0.4 parts for one hundred parts elastomers (phr) of N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine.

The functionalized SBR is dried by vacuum baking (200 torr) at 60 ° C for 1 day.

The reaction is monitored by ¹ H NMR spectroscopy and confirmed by the reduction or disappearance of the vinyl unsaturations signals (δ = 4.9 ppm: = CH 2) and the increase or presence of the epoxide group signals (δ = 3.08 ppm: -CH-O-). The degree of graft function determined by ¹ H NMR spectroscopy is 1.19 mol% over the entire copolymer. The graft yield is 95%.

Distribution of each of the units over the entire copolymer:

SBR1 - Weight% Molar%

% Styrene 27.8 +/- 1.5 16.7 +/- 1.5

% PB 1 -2 14.7 +/- 0.5 20.1 +/- 0.5

% PB 1 -4 54.8 +/- 0.5 63.2 +/- 0.5

% Silane // SBR1 modified% mass% molar

% Styrene 20.6 +/- 1.5 17.9 +/- 1.5

% PB 1 -2 4.7 +/- 0.5 7.9 +/- 0.5

% PB 1 -4 37.7 +/- 0.5 63.1 +/- 0.5

% Silane 36.9 +/- 0.5 1 1.0 +/- 0.5

Example 2

2 g of SBR2 are dissolved in 100 ml of toluene in a 250 ml reactor equipped with mechanical stirring. 4.5 mmol (1, 12 g) of (3-glycidoxypropyl) -1, 1, 3,3-tetramethyldisiloxane and _200, uL of platinum-1, 1, 3,3- tetramethyl-1, 3-divinylsiloxane solution in xylene (Karstedt catalyst) (CAS No. 68478-92-2) are added to the polymer solution and the reaction medium is heated to 60 ° C.

The reaction is monitored by ¹ H NMR spectroscopy and confirmed by the reduction or disappearance of the vinyl unsaturations signals (δ = 4.9 ppm: = CH 2) and the increase or presence of the epoxide group signals (δ = 3.08 ppm: -CH-O-). The degree of graft function determined by ¹ H NMR spectroscopy is 14.4 mol% over the entire copolymer. The grafting yield is 96%.

Distribution of each of the patterns over the entire copolymer SBR2-Control% mass% molar

% Styrene 27.2 +/- 1.5 16.2 +/- 1.5

% PB 1 -2 42.8 +/- 0.5 49.2 +/- 0.5

% PB 1 -4 30.1 +/- 0.5 34.6 +/- 0.5

% Silane //

SBR2 modified% mass% molar

% Styrene 17.5 +/- 1.5 16.5 +/- 1.5

% PB 1 -2 19.2 +/- 0.5 34.4 +/- 0.5

% PB 1 -4 18.9 +/- 0.5 34.8 +/- 0.5

% Silane 44.5 +/- 0.5 14.4 +/- 0.5

Example 3

2 g of EBRI are dissolved in 100 ml of toluene in a 250 ml reactor equipped with mechanical stirring. 4.94 mmol (1, 37 mL) of (3-glycidoxypropyl) -1, 1, 3,3-tetramethyldisiloxane and _200, uL of platinum-1, 1, 3,3- tetramethyl-1, 3-divinylsiloxane solution in xylene (Karstedt catalyst) (CAS No. 68478-92-2) are added to the polymer solution and the reaction medium is heated to 60 ° C.

The polymer then undergoes an antioxidant treatment of 0.4 parts per hundred parts elastomers (phr) of 4,4'-methylene-bis-2,6-tert-butylphenol and 0.4 parts per hundred parts d elastomers (phr) of N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine.

The monitoring of the reaction is carried out by ¹ H NMR spectroscopy and confirmed by the reduction or disappearance of the vinyl unsaturations signals (δ = 4.9 ppm: = CH2) and the increase or presence of epoxide group signals (δ = 3.08 ppm: -CH-O-). The degree of graft function determined by ¹ H NMR spectroscopy is 9.4 mol% over the entire copolymer. The grafting yield is 96%. Distribution of each of the patterns over the entire copolymer

EBR1-% Weight% Molar Weight Indicator

% PB 1 -2 20.3 +/- 1.5 14.6 +/- 1.5

% PB 1 -4 10.6 +/- 1.5 7.6 +/- 1 .5

% cycles 17.5 +/- 1.5 6.2 +/- 1 .5

% PE 51.6 +/- 1.5 71.6 +/- 1.5

EBR1 modified% mass% molar

% PB 1 -2 4.6 +/- 1 .5 5.2 +/- 1 .5

% PB 1 -4 6.7 +/- 1 .5 7.7 +/- 1 .5

% cycles 10.2 +/- 1.5 5.7 +/- 1 .5

% PE 32.5 +/- 1.5 71.9 +/- 1.5

% Silane 46.1 +/- 1.5 9.4 +/- 0.5

Claims

claims

1 - Process for synthesizing a diene polymer comprising pendant epoxide functions along the chain, characterized in that it comprises the step of modifying an unsaturated polymer comprising unsaturations along the chain by hydrosilylation, in reacting the unsaturated polymer with an epoxidized hydrogenosilane of formula 1 in the presence of a hydrosilylation catalyst:

Formula I with R and R _2, identical or different, each being an alkyl group -C _5, C ₆ -C _4, aromatic C ₇ -Cn alkyl;

R _3, R ₄ and R _5, identical or different, each being a hydrogen atom or an alkyl group -C _5, C ₆ -C ₄ alkyl aromatic C ₇ - C11, and preferably a hydrogen atom ;

Y is a bridging group with a valence equal to i + 1; and i is an integer of a value ranging from 1 to 3, and preferably 1.

2 - Process according to claim 1, characterized in that Y is a hydrocarbon chain, linear, branched, cyclic, which may contain one or more aromatic radicals, and / or one or more heteroatoms, such as for example N, O or Si.

3 - Process according to claim 1 or 2, characterized in that the epoxidized hydrogenosilane of formula 1 has at least one of the following four characteristics, preferably the four:

R 1 and R ₂ , which are identical or different, preferably denote a C 1 -C 5 alkyl radical, preferably methyl and ethyl,

R ₃ , R ₄ and R ₅ are identical and represent a hydrogen atom,

Y is a C ₁ -C ₆ linear alkylene linear chain interrupted by at least one oxygen atom separated from the epoxy group by a methylene group and by at least one silicon atom substituted with two identical or different C1-C5 alkyl radicals, preferably methyl and ethyl,

i is 1.

4 - Process according to claim 3, characterized in that the epoxidized hydrogenosilane of formula 1 is chosen from (3-glycidoxypropyl) -1,1,3,3-tetramethyldisiloxane (Formula A), 3,7-Dioxa-2 , 4-disilaoctane 2,4,4-trimethyl-8- (2-oxiranyl) (Formula B), 2,7-Dioxa-6,8-disiladecane 6-ethyl-6,8-dimethyl-1 - (2- oxiranyl) (Formula C):

Me

Formula A Me 2

Me

Formula B

Me

Form C

5 - Process according to any one of the preceding claims, characterized in that the unsaturated polymer is one of the following polymers:

(b) any copolymer obtained by copolymerization of one or more of the conjugated dienes with each other or with one or more ethylenically unsaturated monomers. (c) any homopolymer obtained by polymerization of a non-conjugated diene monomer having 5 to 12 carbon atoms,

(d) any copolymer obtained by copolymerization of one or more of the non-conjugated dienes with each other or with one or more ethylenically unsaturated monomers.

(e) a ternary copolymer obtained by copolymerizing ethylene, an olefin having 3 to 6 carbon atoms with a non-conjugated diene monomer having 6 to 12 carbon atoms;

(f) a copolymer of isobutene and isoprene (butyl rubber), as well as halogenated versions;

(g) natural rubber;

(h) an unsaturated olefinic copolymer whose chain comprises at least olefinic monomeric units and diene units;

(i) a mixture of several of the elastomers defined in (a) to (h) between them. 6 - Process according to claim 5, characterized in that the conjugated diene monomer is butadiene-1,3, 2-methyl-1,3-butadiene, 2,3-di (C1-C5) alkyl-1 3-butadienes, such as, for example, 2,3-dimethyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2-methyl-3-ethyl-1,3-butadiene, 2-methyl-3-isopropyl-1,3-butadiene, aryl-1,3-butadiene, 1,3-pentadiene or 2,4-hexadiene. 7 - Process according to claim 5 or 6, characterized in that the ethylenically unsaturated monomer is a vinylaromatic monomer having from 8 to 20 carbon atoms, a vinyl nitrile monomers having 3 to 12 carbon atoms or an acrylic ester monomer derived from acrylic acid or methacrylic acid with an alcohol having 1 to 12 carbon atoms. 8 - Process according to claim 5 or 6, characterized in that the olefinic monomer is ethylene or an oolefin having 3 to 6 carbon atoms.

9 - Process according to any one of the preceding claims, characterized in that the unsaturated polymer comprises a mass content of at least 1% and at most 100% unsaturated units relative to the total weight of the polymer. 10 - Process according to any one of the preceding claims, characterized in that the unsaturated polymer is chosen from polybutadienes (abbreviated as "BR"),

the synthetic polyisoprenes (IR),

natural rubber (NR),

copolymers of butadiene, copolymers of isoprene, copolymers of ethylene-diene, more preferably selected from the group consisting of butadiene-styrene copolymers (SBR), copolymers of isoprene-butadiene (BIR), copolymers isoprene-styrene (SIR), isoprene-butadiene-styrene copolymers (SBIR) and ethylene-butadiene copolymers (EBR), and

mixtures of these polymers.

1 1 - Diene polymer comprising units bearing a pendant epoxide function along the chain and linked thereto via a silicon atom.

12 - Polymer according to claim 1 1, characterized in that the pendant epoxide function along the chain corresponds to formula 2

Formula 2

With

with R and R _2, identical or different, each being an alkyl group -C _5, C ₆ -C _4, aromatic C ₇ -Cn alkyl;

C ₁₁ , and preferably a hydrogen atom;

Y is a bridging group with a valence equal to i + 1; and i is an integer of a value ranging from 1 to 3, and preferably 1;

^* denotes a point of connection with the polymer chain.

13 - Polymer according to claim 1 1 or 12, characterized in that it comprises units carrying a pendant epoxide function along the chain and bonded thereto via a silicon atom, at a molar level of at least 0.1% and at most 20%, and unoxidized units at a molar level of at most 99.9% and at least 80%, molar levels being measured relative to the polymer. 14 - Polymer according to any one of the preceding claims, characterized in that the non-epoxidized units comprise units derived from at least one conjugated diene monomer, such as butadiene-1,3, 2-methyl-1,3 2-butadiene, 2,3-di (C 1 -C 5) -alkyl-1,3-butadienes, such as, for example, 2,3-dimethyl-1,3-butadiene, 2,3-diethyl-1,3- butadiene, 2-methyl-3-ethyl-1,3-butadiene, 2-methyl-3-isopropyl-1,3-butadiene, aryl-1,3-butadiene, 1,3-pentadiene or 2-methyl-1,3-butadiene; , 4-hexadiene.

Polymer according to any one of the preceding claims, characterized in that the non-epoxidized units comprise units derived from at least one monoolefin, such as ethylene, propylene, butylene, isobutylene. 16 - Polymer according to any one of the preceding claims, characterized in that the non-epoxidized units comprise units derived from at least one ethylenically unsaturated monomer, such as a vinylaromatic monomer having from 8 to 20 carbon atoms, a nitrile monomer vinyl compound having 3 to 12 carbon atoms or an acrylic ester monomer derived from acrylic acid or methacrylic acid with an alcohol having 1 to 12 carbon atoms.

17. A rubber composition based on at least one elastomer comprising epoxide functions as prepared according to the process defined in any one of claims 1 to 10 or as defined in any one of claims 1 to 16 and at least one reinforcing filler. 18 - A tire of which one of its constituent elements comprises a rubber composition according to claim 17.