KR20200104351A - Compounds comprising at least two trialkoxysilyl groups, their use as diene elastomer functionalizing agents, modified diene elastomers and compositions containing modified diene elastomers - Google Patents

Abstract

상기 화학식 I에서,
R은 서로 독립적으로, C₁-C₄ 알킬 라디칼, 바람직하게는 메틸 또는 에틸 라디칼을 나타내고,
G1 및 G2는 서로 독립적으로, 탄소수 5, 6 또는 7의 선형 포화 2가 지방족 그룹을 나타내고,
X는 적어도 하나의 질소 원자를 포함하는 그룹을 나타내고,
m은 1 내지 20의 정수이다.
디엔 엘라스토머 작용화제로서 이러한 부류의 분자를 사용하면, 저장하는 동안, 이러한 방식으로 개질된 디엔 엘라스토머의 마크로구조의 안정화를 상당히 개선시킬 수 있다.The present invention relates to a new class of molecules corresponding to formula (I).
Formula I

In Formula I,
R independently of each other represent a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical,
G1 and G2 represent, independently of each other, a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms,
X represents a group containing at least one nitrogen atom,
m is an integer from 1 to 20.
The use of molecules of this class as diene elastomer functionalizing agents can significantly improve the stabilization of the macrostructure of diene elastomers modified in this way during storage.

Description

Compounds comprising at least two trialkoxysilyl groups, their use as diene elastomer functionalizing agents, modified diene elastomers and compositions containing modified diene elastomers

The present invention relates to a novel class of molecules comprising silicon and nitrogen atoms. The invention also relates to a method of using this class of molecules as functionalizing agents for the purpose of modifying the diene elastomers and to the diene elastomers modified accordingly. The invention also relates to a rubber composition containing the elastomer, which composition can be used in particular in the manufacture of tires.

Since the need to save fuel and protect the environment has been given priority, hysteresis has been developed so that the polymer can be processed in the form of a rubber composition that can be used in the manufacture of various semi-finished products involved in the formation of tires. It is desirable to produce polymers with as low as possible and good mechanical properties. A number of solutions have already been tested to achieve the goal of reducing hysteresis. In particular, it will be mentioned to modify the structure of the diene polymer by a compound introducing a functional group into the diene polymer at the end of polymerization for the purpose of obtaining good interaction with the modified polymer with the filler, whether it is carbon black or other reinforcing fillers. I can. In particular, it has been proposed to use functionalized diene polymers having silanol or alkoxysilane functionality. Many functionalizing agents comprising one or more groups comprising silicon atoms forming silanol or alkoxysilane functional groups at the end of the synthesis are described in the literature.

For the purpose of further improving the functionalization effect of the diene elastomer on the properties of the rubber composition containing the diene elastomer, functionalization with an alkoxysilane or silanol functional group, in particular, with other functional groups including nitrogen atoms, It was also proposed to combine. Although the properties of the rubber composition are sometimes contradictory, this double functionalization makes it possible to improve a compromise particularly in terms of the properties of a rubber composition comprising a modified diene elastomer.

Thus, for example, EP 2 003 146 A2, US 2014/0243476 A1 and JP 201617097 A describe functionalizing agents having both at least one silicon atom and at least one nitrogen atom. These documents propose improvement of the mechanical and dynamic properties of rubber compositions for the purpose of tire application, and in particular emphasize the increase of wet road surface traction, improvement of heat dissipation, improvement of rolling resistance or other improvement of wear.

In addition, it has been found that under certain storage conditions prior to use in rubber compositions, aging of diene elastomers modified with alkoxysilane groups having other functional groups including amine groups highly modify their microstructure.

Without being bound only by the above interpretation, the present inventors believe that these modified elastomers exhibit instability upon storage as a result of the hydrolysis and condensation reaction of the alkoxysilyl functional group, thereby changing the macrostructure of the elastomer.

This phenomenon is known. Thus, one solution proposed by EP 0 299 074 A1 is to use compounds of the alkoxysilane type as functionalizing agents, the alkoxy groups of which are not hydrolyzable. The choice of such non-hydrolyzable groups reduces the likelihood of obtaining commercially or economically advantageous compounds, and also affects the reactivity of these compounds with respect to living polymers and thus the properties of rubber compositions comprising functionalized elastomers. Crazy.

Other methods of stabilizing the macrostructure of diene elastomers functionalized by alkoxysilyl functional groups have been proposed previously. Some of these methods consist of the addition of small molecules that can be condensed on the alkoxysilyl functional groups of the elastomer, consequently blocking their reactivity. Thus, document US 2015166738 proposes to add a stabilizer comprising silanol, silanol or silantriol groups after a functionalization step during the synthesis of the modified polymer. In the same context, document US 2015166738 proposes to add an alkoxysilane compound as a stabilizer after the functionalization step during the synthesis of the modified polymer.

Similar methods using stabilizers of various properties are described in documents US 5 659 056, US 6 255 404 and US 6 279 632. These stabilizer compounds are added after the functionalization step during the synthesis of the alkoxysilane-functionalized polymer and before the step of contacting with water.

Nonetheless, all of these methods require the addition of stabilizers during the synthesis of diene elastomers functionalized with alkoxysilyl groups.

[The task to be solved]

The technical problem to be solved by the present invention is to stabilize the macrostructure of a diene elastomer modified with an alkoxysilyl group having an amine functional group by slowing the change in the macrostructure or even suppressing the change.

[Means to solve the problem]

It is an object of the present invention that the present inventors have demonstrated that the modification of the diene elastomer with a specific functionalizing agent is stable during storage as long as it does not show significant changes in the macrostructure during storage for at least 1 month. Was achieved in things.

[Content of the invention]

Thus, the subject matter of the present invention is a novel class of molecules that, when used as functionalizing agents, make it possible to obtain modified diene elastomers that do not show any significant changes in macrostructure during storage for at least 1 month. Molecules of this class contain at least two trialkoxysilyl groups in the molecular structure, the trialkoxysilyl groups are connected to each other by a group containing at least one nitrogen atom, and the bond between the silicon atom and the nitrogen atom is a number of carbon atoms. 5, 6 or 7 linear saturation occurs by spacers defined by divalent aliphatic groups.

Another subject of the present invention is a method of synthesizing a modified diene elastomer, wherein a living diene elastomer resulting from the polymerization of at least one diene monomer is selected from a novel class of molecules comprising at least two trialkoxysilyl groups. As a step of reacting with, the trialkoxysilyl groups are connected to each other by a group containing at least one nitrogen atom, and the bond between the silicon atom and the nitrogen atom is a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms. It is a method of synthesizing a modified diene elastomer, comprising the step of reacting, generated by a defined spacer.

A further subject of the present invention is a modified diene elastomer obtained directly by the synthetic method described above.

The modified diene elastomer, which is the subject of the present invention, specifically comprises a branching unit comprising at least two silicon atoms connected to each other by a group containing at least one nitrogen atom, in the elastomer structure, and a silicon atom and Bonds between nitrogen atoms occur by spacers defined as linear saturated divalent aliphatic groups of 5, 6 or 7 carbon atoms.

Another subject matter of the invention is a rubber composition based on at least one modified diene elastomer according to the invention.

Another subject of the invention is a tire comprising the rubber composition according to the invention.

In the present specification, unless otherwise specified, all percentages (%) given are% by mass. The abbreviation “phr” means parts by weight per 100 parts of elastomer present in the elastomer matrix, and the elastomer matrix refers to all elastomers present in the rubber composition.

In addition, any interval of values denoted by the expression "between a and b" denotes a range of values from above "a" to below "b" (ie, excluding limits a and b). ), any interval of values denoted by the expression "a to b" means a range of values extending from "a" to "b" (i.e., including strict limits a and b) do). In the present specification, when an interval of values is represented by the expression "a to b", the interval represented by the expression "between a and b" also means preferentially.

In this patent application, "predominantly" or "predominant" means that the compound is major among the compounds of the same type in the composition with respect to the compound, i.e., the most It should be understood that it is meant to represent a large weight fraction. Thus, for example, the primary elastomer is the elastomer that exhibits the largest weight fraction relative to the total weight of the elastomer in the composition. In the same way, the “major” filler is the filler that exhibits the largest weight fraction relative to the total weight of the blended filler of the composition. In addition, the "main" functional entity of the modified diene elastomer represents the largest weight fraction of the functionalized entities constituting the diene elastomer relative to the total weight of the modified diene elastomer. In systems containing only one compound of a particular type, the latter is the main one within the meaning of the present invention.

The expression “composition based on” is to be understood as meaning a composition comprising a mixture of various components and/or reaction products in situ as used herein, and these basic components (eg For example, some of the elastomers, fillers or other additives commonly used in rubber compositions intended for the manufacture of tires) may at least partially react with each other or with each other during the various stages of manufacture of the composition intended for the manufacture of tires. May be intended to react.

In the present specification, the term "modified diene elastomer" refers to an entity (or macromolecule) produced by a functionalization reaction using a compound containing at least 6 functional groups (alkoxy functional groups replacing silicon atoms) reactive to the reactive end of the diene elastomer. Molecules), the compound comprising several heteroatoms comprising at least two silicon atoms and at least one nitrogen atom.

The skilled artisan is a linear entity of a modified elastomer, and at least three branches and modifications with an agent comprising one or more functional groups reactive towards living elastomers (alkoxy functional groups carried by silicon atoms in this case). Functionalized (also referred to as coupled) at the end of the chain and in the middle of the chain constituting the branched entity comprising as many branches as the reactive functional groups involved by the functionalizing agent constituting the branched entity of the elastomer It will be understood that it results in a mixture of entities (or macromolecules). Depending on the operating conditions, primarily the molar ratio of the functionalizing agent to the living chain, certain entities are less or more present in the mixture, or even major.

In this specification, the expression “monomer unit”, whether diene or otherwise, is understood as a unit of a polymer resulting from that monomer.

As used herein, the expression “branching unit” is understood as a non-repeating unit (there is only one in the polymer) derived from a functionalizing agent from which the living diene elastomer chain(s) react and the diene elastomer chain(s) emerge.

It should be noted that, in the context of the present invention, the monomers used may be of fossil or biosource origin. In the latter case, they may be produced partially or entirely from biomass or they may be obtained from renewable starting materials produced from biomass.

Accordingly, the subject of the present invention is a novel class of molecules containing at least two trialkoxysilyl groups in the molecular structure, wherein the alkoxysilyl groups are connected to each other by a group containing at least one nitrogen atom, and a silicon atom The bond between and the nitrogen atom occurs by a spacer group defined as a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms.

The molecules according to the invention most specifically correspond to formula I.

Formula I

In Formula I,

R independently of each other represent a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical,

G1 and G2 represent, independently of each other, a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms,

X represents a group containing at least one nitrogen atom,

m is an integer from 1 to 20.

를 나타내고, Y는 C₁-C₄ 알킬 라디칼, 바람직하게는 메틸 또는 에틸 라디칼, 또는 C₆-C₁₈ 아릴 라디칼, 바람직하게는 C₆ 아릴 라디칼, 또는 트리알킬실릴 라디칼이거나, 또는 그룹

을 나타내고, R₁은 탄소수 1 내지 18의 선형 또는 분지형 2가 탄화수소계 그룹을 나타내고, A는 질소 원자를 포함하는 그룹이다.According to an alternative form of the invention, X is a group

And Y is a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical, or a C ₆ -C ₁₈ aryl radical, preferably a C ₆ aryl radical, or a trialkylsilyl radical, or a group

And R ₁ represents a linear or branched divalent hydrocarbon-based group having 1 to 18 carbon atoms, and A is a group containing a nitrogen atom.

를 나타내고, Y는 C₁-C₄ 알킬 라디칼, 또는 C₆ 아릴 라디칼, 또는 트리알킬실릴 라디칼을 나타내는 분자로서, 예를 들면, 화합물 비스(트리에톡시실릴알킬)메틸아민, 비스(트리에톡시실릴알킬)에틸아민, 비스(트리에톡시실릴알킬)프로필아민, 비스(트리에톡시실릴알킬)부틸아민, 및 비스(트리에톡시실릴알킬)페닐아민, 및 이들 트리에톡시실릴 화합물에 대응하는 트리메톡시실릴 화합물, 및 화합물 비스(트리메톡시실릴알킬)-N-트리메틸실릴아민 및 비스(트리에톡시실릴알킬)-N-트리메틸실릴아민(여기서, 알킬 라디칼은 C₅, C₆ 또는 C₇ 라디칼이다)을 언급할 수 있다.Functional group X is a group

And Y is a molecule representing a C ₁ -C ₄ alkyl radical, or a C ₆ aryl radical, or a trialkylsilyl radical, for example, the compound bis(triethoxysilylalkyl)methylamine, bis(triethoxy Silylalkyl)ethylamine, bis(triethoxysilylalkyl)propylamine, bis(triethoxysilylalkyl)butylamine, and bis(triethoxysilylalkyl)phenylamine, and corresponding to these triethoxysilyl compounds Trimethoxysilyl compound, and the compound bis(trimethoxysilylalkyl)-N-trimethylsilylamine and bis(triethoxysilylalkyl)-N-trimethylsilylamine (wherein the alkyl radical is C ₅ , C ₆ or C ₇ radicals).

를 나타내고, Y는 그룹

를 나타내고, R₁은 탄소수 1 내지 18의 선형 또는 분지형 2가 탄화수소계 그룹을 나타내고, A는 질소 원자를 포함하는 그룹인 분자로서, 예를 들면, 화합물 비스(트리에톡시실릴알킬)-(3-메틸아미노프로필)아민, 비스(트리에톡시실릴알킬)-(3-헥사메틸렌아미노프로필)아민, 비스(트리에톡시실릴알킬)-(3-이미다졸프로필)아민 및 비스(트리에톡시실릴알킬)-(3-디하이드로이미다졸프로필)아민, 및 이들 트리에톡시실릴 화합물에 대응하는 트리메톡시실릴 화합물(여기서, 알킬 라디칼은 C₅, C₆ 또는 C₇ 라디칼이다)을 언급할 수 있다.Functional group X is a group

And Y is a group

Represents, R ₁ represents a linear or branched divalent hydrocarbon group having 1 to 18 carbon atoms, and A represents a molecule which is a group containing a nitrogen atom, for example, the compound bis(triethoxysilylalkyl)-( 3-methylaminopropyl)amine, bis(triethoxysilylalkyl)-(3-hexamethyleneaminopropyl)amine, bis(triethoxysilylalkyl)-(3-imidazolepropyl)amine and bis(triethoxy Silylalkyl)-(3-dihydroimidazolepropyl)amine, and trimethoxysilyl compounds corresponding to these triethoxysilyl compounds, wherein the alkyl radical is a C ₅ , C ₆ or C ₇ radical. I can.

를 나타내고, G3은 탄소수 5, 6 또는 7의 선형 포화 2가 지방족 그룹을 나타내고, R''는 C₁-C₄ 알킬 라디칼, 바람직하게는 메틸 또는 에틸 라디칼을 나타내고, 라디칼 R들은 서로 독립적으로, C₁-C₄ 알킬 라디칼, 바람직하게는 메틸 또는 에틸 라디칼을 나타내고, a는 0 또는 1이다.According to another alternative form of the invention, X is a group

, G3 represents a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms, R'' represents a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical, and the radicals R are independently of each other, C ₁ -C ₄ Represents an alkyl radical, preferably a methyl or ethyl radical, and a is 0 or 1.

를 나타내는 분자로서, 예를 들면, 화합물 비스(트리에톡시실릴알킬)디에톡시메틸실릴알킬아민 및 비스(트리에톡시실릴알킬)디에톡시실릴알킬아민(여기서, 알킬 라디칼은 C₅, C₆ 또는 C₇ 라디칼이다) 및 또한 이들 화합물에 상응하는 트리메톡시 화합물 및 디메톡시 화합물을 언급할 수 있다.Functional group X is a group

As a molecule representing, for example, the compound bis(triethoxysilylalkyl)diethoxymethylsilylalkylamine and bis(triethoxysilylalkyl)diethoxysilylalkylamine (wherein the alkyl radical is C ₅ , C ₆ or C ₇ radical) and also trimethoxy compounds and dimethoxy compounds corresponding to these compounds.

을 나타내는 분자로서, 예를 들면, 화합물 트리스(트리에톡시실릴알킬)아민 및 트리스(트리메톡시실릴알킬)아민(여기서, 알킬 라디칼은 C₅, C₆ 또는 C₇ 라디칼이다)을 언급할 수 있다.Functional group X is a group

As a molecule representing, for example, the compounds tris(triethoxysilylalkyl)amine and tris(trimethoxysilylalkyl)amine (wherein the alkyl radical is a C ₅ , C ₆ or C ₇ radical) can be mentioned. have.

According to another alternative form of the invention, X represents a group of formula II.

Formula II

In Formula II,

R''' may be the same or different and represent a linear or branched divalent aliphatic C ₁ -C ₁₈ group, preferably a methylene or ethylene group.

As a molecule in which the functional group X represents a group of formula II, for example, the compounds bis(trimethoxysilylalkyl)piperazine, bis(triethoxysilylalkyl)piperazine, bis(trimethoxysilylalkyl)imidazoli Dine, bis(triethoxysilylalkyl)imidazolidine, bis(trimethoxysilylalkyl)hexahydropyrimidine and bis(triethoxysilylalkyl)hexahydropyrimidine, wherein the alkyl radical is C ₅ , C ₆ or C ₇ radicals).

According to a preferred alternative form of the invention, which can each be combined with the preceding alternative forms with respect to the functional group X, both G1 and G2 represent a hexamethylene group -(CH ₂ ) ₆ -.

According to a preferred alternative form of the invention, which can be combined with the alternative forms respectively preceding with respect to the functional group X and with respect to the functional groups G1 and G2, m is 1.

를 나타내고, Y는 C₁-C₄ 알킬 라디칼, 바람직하게는 메틸 또는 에틸 라디칼을 나타내며, G1 및 G2는 둘 다 헥사메틸렌 그룹 -(CH₂)₆-을 나타내고, m은 1인 화학식 I에 상응한다.According to a particularly preferred alternative form of the invention, the molecule according to the invention is in which the radicals R represent methyl or ethyl radicals, and X is a group

And Y represents a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical, G1 and G2 both represent a hexamethylene group -(CH ₂ ) ₆ -, and m corresponds to the formula I in which 1. do.

Among these preferred molecules, for example, bis(6-triethoxysilylhexyl)methylamine, bis(6-triethoxysilylhexyl)ethylamine, bis(6-triethoxysilylhexyl)propylamine and bis( 6-triethoxysilylhexyl)butylamine and trimethoxysilyl compounds corresponding to these triethoxysilyl compounds, and the compounds bis(6-trimethoxysilylhexyl)-N-trimethylsilylamine and bis(6-tri Ethoxysilylhexyl)-N-trimethylsilylamine may be mentioned.

The synthesis of a new class of molecules according to the invention is within the scope of a person skilled in the art. In particular, methods similar to those for synthesizing structurally similar compounds described, for example, in the literature should be used.

The molecules according to the invention described above can be advantageously used as functionalizing agents for the purpose of providing a modified diene elastomer that does not show any significant changes in the macrostructure during storage for at least 1 month.

Accordingly, another subject matter of the present invention is a method for synthesizing a modified diene elastomer, wherein a living diene elastomer resulting from the polymerization of at least one diene monomer is selected from the above-described molecules comprising at least two trialkoxysilyl groups. In the step of reacting with an agent, the trialkoxysilyl groups are connected to each other by a group containing at least one nitrogen atom, and the bond between the silicon atom and the nitrogen atom is a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms. It is a method of synthesizing a modified diene elastomer, comprising the step of reacting, generated by a spacer group defined as.

The polymerization step according to the invention can be carried out, for example, by anionic polymerization initiated by an organic compound of an alkali metal or an alkaline earth metal. According to another embodiment of the method of the invention, this polymerization step may be a chain polymerization by catalytic reaction (according to a coordination-insertion mechanism) using a catalyst system based on rare earth metals, titanium or other transition metals. Polymerization of at least one conjugated diene monomer according to these different embodiments produces elastomeric chains having reactive sites at the chain ends. Depending on the polymerization method used, these sites are somewhat reactive. Subsequently, the commonly used term is (pseudo-) living elastomer or (pseudo-) living chain.

With regard to the anionic polymerization, the polymerization initiator can be any known monofunctional or polyfunctional anionic initiator. However, an initiator containing an alkali metal such as lithium is preferentially used. Suitable organic lithium initiators are in particular initiators comprising at least one carbon-lithium bond or at least one nitrogen-lithium bond. Representative compounds are aliphatic organolithium compounds such as ethyllithium, n-butyllithium (n-BuLi) or isobutyllithium, or obtained from cyclic secondary amines such as pyrrolidine and hexamethyleneimine. It is lithium amide. Such anionic polymerization initiators are known to those skilled in the art.

With regard to chain polymerization by coordination catalytic reaction, catalyst systems based on rare earth metals, titanium or other transition metals are used. Such catalyst systems are fully described in the literature and are known to those skilled in the art.

The polymerization can be carried out continuously or batchwise in a manner known per se. The polymerization is generally carried out at temperatures between 0°C and 110°C, preferably between 50°C and 100°C, or even at temperatures between 70°C and 90°C. The temperature can be kept constant throughout this step or can vary depending on the target characteristics of the synthesized elastomer. The polymerization process can be carried out in solution, in a somewhat concentrated medium, or in a dilute medium. The polymerization solvent is preferably an inert hydrocarbon solvent, and may be, for example, an aliphatic or alicyclic hydrocarbon such as pentane, hexane, heptane, isooctane, cyclohexane or methylcyclohexane, or an aromatic hydrocarbon such as benzene, toluene or xylene.

Preferably, the polymerization is an anionic polymerization, which makes it possible to achieve a higher content of functionalized chains than that obtained by polymerization by coordination catalysis. Thus, preferentially, the process which is the subject of the present invention comprises an anionic polymerization step of at least one conjugated diene monomer in the presence of an anionic polymerization initiator, in particular an initiator comprising a carbon-lithium bond.

As conjugated diene monomers the following are particularly suitable: 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-di(C ₁ -C ₅ alkyl)-1,3-butadiene, eg For example 2,3-dimethyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2-methyl-3-ethyl-1,3-butadiene or 2-methyl-3-isopropyl- 1,3-butadiene, aryl-1,3-butadiene, 1,3-pentadiene or 2,4-hexadiene. Preferably, the conjugated diene monomer is 1,3-butadiene or 2-methyl-1,3-butadiene.

According to some alternative forms of the method of the present invention, the conjugated diene monomer may be homopolymerized.

According to another alternative form of the method of the present invention, the conjugated diene monomer may be copolymerized with one or more conjugated diene monomers and/or one or more vinyl aromatic compounds having 8 to 20 carbon atoms. As vinyl aromatic compounds the following are particularly suitable: styrene, ortho-, meta- or para-methylstyrene, α-methylstyrene, commercial mixtures "vinyltoluene", para-(tert-butyl)styrene, methoxystyrene, vinyl Mesitylene, divinylbenzene, vinylnaphthalene, etc., preferentially styrene.

With respect to the copolymerization of at least one conjugated diene monomer and at least one vinyl aromatic monomer, the proportion of each monomer is from 20% to 99% by weight of diene units, and from 1% to 1% by weight of units derived from vinyl aromatic monomers. It should contain 8% by weight. Preferentially, the conjugated diene monomer is 1,3-butadiene, and the vinyl aromatic monomer is styrene.

According to another alternative form of the method of the present invention, the conjugated diene monomer may in particular be copolymerized with one or more other ethylenically unsaturated monomers in addition to the conjugated diene monomer or vinyl aromatic monomer. Thus, among these ethylenically unsaturated monomers, mention may be made of ethylene, propylene, 1-butene, isobutylene, pentene, methylpentene or 1-hexene. Ethylene or propylene will be chosen preferably.

In order to refine the microstructure of the diene elastomer, a modifier and/or a randomizing agent may be optionally added in an appropriate amount. This is within the general knowledge of a person skilled in the art.

These alternative forms of the polymerization step can be combined with the preferred or alternative alternative forms and embodiments described below.

The polymerization of at least one conjugated diene monomer according to the present invention produces an elastomeric chain having a reactive site at the end of the chain. According to one preferred embodiment, the polymerization in the context of the invention is anionic and is carried out in the presence of a polymerization initiator. Subsequently, the terms commonly used are living elastomers or living chains. These living chains or living elastomers then react on the functionalizing agent during the functionalization step. The modifier includes at least one group reactive toward the reactive site of the elastomer, and in this case includes an alkoxy group substituting a silicon atom.

The amount of functionalizing agent intended to react with the living diene elastomer depends essentially on the type of modified diene elastomer desired. In general, the molar ratio of the groups of the agents reactive toward the living elastomer to the metal of the polymerization initiator is less than 5, in particular in the range of 0.1 to 2. Thus, according to certain alternative forms of the invention, the molar ratio of functionalizing agent to metal of the polymerization initiator is in the range of 0.30 to 0.75, preferentially in the range of 0.35 to 0.65, and even more preferentially in the range of 0.45 to 0.55. to be. According to another alternative form of the invention, the molar ratio of the functionalizing agent to the metal of the polymerization initiator is greater than 0.5, greater than 0.65, preferentially greater than 1, or else in the range of 0.65 to 1.45. According to another alternative form of the invention, the molar ratio of the functionalizing agent to the metal of the polymerization initiator is in the range of 0.25 to 0.35.

Conditions for adding a modifier to the elastomer and reacting the modifier with the elastomer are common in terms of the anionic polymerization modification with an aminated alkoxysilane compound, and are known to those skilled in the art. These terms do not include any specific restrictions.

Modifiers are selected from the novel class of molecules described above according to both their preferred alternative forms and embodiments. In particular, modifiers are selected from molecules corresponding to formula I according to both their preferred alternative forms and embodiments.

Thus, according to one alternative particularly advantageous for the present invention, the method for synthesizing diene elastomers is

a. In the presence of an anionic initiator comprising a carbon-lithium bond, anionic polymerization of at least one diene monomer, preferentially butadiene, or of at least one diene monomer, preferentially butadiene and at least one vinyl aromatic monomer, preferably styrene. Anionic polymerization; And

를 나타내고, Y가 C₁-C₄ 알킬 라디칼, 바람직하게는 메틸 또는 에틸 라디칼을 나타내고, G1 및 G2는 둘 다 헥사메틸렌 그룹 -(CH₂)₆-를 나타내고, m은 1인 화학식 I에 상응하는 분자로부터 선택된 특정 작용화제와의 반응을 포함한다.b. The living diene elastomer obtained in the above step, and the radical R represents a methyl or ethyl radical, and X is a group

And Y represents a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical, G1 and G2 both represent a hexamethylene group -(CH ₂ ) ₆ -, and m is 1 And reactions with specific functionalizing agents selected from those molecules.

At the end of these polymerization and functionalization steps, the process for synthesizing the modified diene elastomer according to the invention can be continued by a step of recovery of the modified elastomer in a manner known per se.

The modified diene elastomer according to the method described above is also a subject of the present invention.

The subject of the invention is, in particular, a modified diene elastomer comprising a branching unit that is at least n-functional, wherein the branching units are substituted with a branch of the elastomer and are linked to each other by a group comprising at least one nitrogen atom. It consists of a group containing four silicon atoms, wherein n is 1 or more, preferably 3 or more and 9 or less, preferably 6 or less, and the bond between the silicon atom and the nitrogen atom is linear saturation of 5, 6 or 7 carbon atoms. It is caused by a spacer group defined as a divalent aliphatic group.

The diene elastomer is preferably polybutadiene (BR), synthetic polyisoprene (IR), butadiene copolymer, in particular a copolymer of butadiene and a vinyl aromatic monomer or a copolymer of butadiene and an aliphatic monoolefin, isoprene copolymer and mixtures of these elastomers. It is selected from the group of diene elastomers consisting of. Such copolymers are more particularly butadiene/styrene copolymer (SBR), butadiene/ethylene copolymer (EBR), isoprene/butadiene copolymer (BIR), isoprene/styrene copolymer (SIR) and isoprene/butadiene/styrene copolymer ( SBIR). Among these copolymers, a butadiene/styrene copolymer (SBR) is particularly preferable.

The elastomer may be block, random, sequential, microsequential, or the like.

Diene elastomers can have any microstructure.

According to one preferred aspect of the invention, the modified diene elastomer according to the invention comprises at least two silicon atoms in the elastomeric structure. These silicon atoms may be substituted with one or more alkoxy groups and up to three alkoxy groups.

Alkoxy groups substituting silicon atoms may be partially or completely hydrolyzed to provide hydroxyl groups according to some alternative forms of the invention. According to these alternative forms, all or at least 50 mole percent of the alkoxy functional groups involved by the modified diene elastomer are hydrolyzed to provide hydroxyl groups. In particular, at least 80 mol%, actually even 100%, of the alkoxy functional groups involved by the modified diene elastomer are hydrolyzed to provide hydroxyl groups.

The alkyl radicals of the alkoxy group substituting a silicon atom are independently of each other, C ₁ -C ₁₀ Alkyl radical Or even C ₁ -C ₈ alkyl radicals, preferably C ₁ -C ₄ alkyl radicals, more preferentially selected from methyl and ethyl.

According to the invention, the branching unit comprises at least two silicon atoms, these silicon atoms are connected to each other by a group comprising at least one nitrogen atom, and the bond between the silicon atom and the nitrogen atom is 5, 6 or It occurs by a spacer defined by a linear saturated divalent aliphatic group of 7, preferably a hexamethylene group -(CH ₂ ) ₆ -.

This characteristic, related to the nature of the spacer group, is of particular importance in the context of the present invention and contributes significantly and unexpectedly to the stabilization of the macrostructure of the modified diene elastomer during storage.

The modified diene elastomers of the present invention most specifically correspond to formula III:

Formula III

In Formula III,

E represents a diene elastomer branch,

The radicals R independently of each other represent a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical,

G1 and G2 represent, independently of each other, a linear saturated divalent aliphatic group having 5, 6 or 7, preferentially 6 carbon atoms,

X represents a group containing at least one nitrogen atom,

i and j are each independently an integer of 0 to 3,

i+j is 1 or more and 6 or less, preferably 5 or less, and even more preferably 4 or less,

m is an integer of 1 to 20, preferentially an integer of 1.

Advantageously, in Formula III, i and j are such that i+j is 3 or more and 6 or less.

를 나타내고, Y는 C₁-C₄ 알킬 라디칼, 바람직하게는 메틸 또는 에틸 라디칼, 또는 C₆-C₁₈ 아릴 라디칼, 바람직하게는 C₆ 아릴 라디칼, 또는 트리알킬실릴 라디칼이거나, 또는 그룹

을 나타내고, R₁은 탄소수 1 내지 18의 선형 또는 분지형 2가 탄화수소계 그룹을 나타내고, A는 질소 원자를 포함하는 그룹이다.According to an alternative form of the invention, X is a group

And Y is a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical, or a C ₆ -C ₁₈ aryl radical, preferably a C ₆ Aryl radical, or trialkylsilyl radical, or a group

And R ₁ represents a linear or branched divalent hydrocarbon-based group having 1 to 18 carbon atoms, and A is a group containing a nitrogen atom.

According to another alternative form of the invention, X represents a group of formula II.

Formula II

In Formula II,

R''' may be the same or different and represent a linear or branched divalent aliphatic C ₁ -C ₁₈ radical, preferably a methylene or ethylene radical.

According to another alternative form of the present invention, the modified diene elastomer is

m is 1,

를 나타내고, X group

Represents,

G3 represents a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms,

R" represents a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical,

The radicals R independently of each other represent a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical,

a is an integer of 0 or 1,

k is an integer from 0 to 3,

a+k is 3 or less,

However, i+j+k corresponds to Formula III, which is 1 or more and 9 or less, preferably 8 or less, more preferentially 7 or less, and even more preferentially 6 or less.

를 나타내고, Y는 C₁-C₄ 알킬 라디칼, 바람직하게는 메틸 또는 에틸 라디칼, 특히 메틸 라디칼을 나타내는 화학식 III에 상응한다. According to the invention, the modified diene elastomers correspond preferentially to formula III in which m is 1. Even more preferentially, the modified diene elastomer preferentially has m = 1 and X = group

And Y corresponds to formula III representing a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical, in particular a methyl radical.

The modified diene elastomer according to one preferred alternative aspect of the invention comprises a branched diene elastomer comprising four branches, at least 50% by weight, preferably at least 80% by weight, based on the total weight of the modified diene elastomer. Include.

The modified diene elastomer according to another preferred alternative aspect of the invention comprises a branched diene elastomer comprising three branches, at least 30% by weight, preferably at least 40% by weight, based on the total weight of the modified diene elastomer. do.

Various preferred alternative forms and aspects relating to the nature of the modified diene elastomer, alkoxysilane functional group, spacer group and group comprising at least one nitrogen atom can be combined with each other depending on their compatibility.

According to an advantageous alternative form of the invention, it comprises a branching unit comprising at least two silicon atoms connected to each other by a group comprising at least one nitrogen atom in the elastomeric structure, wherein the bond between the silicon atom and the nitrogen atom is a carbon number. Modified diene elastomers arising by spacer groups defined by 5, 6 or 7 linear saturated divalent aliphatic groups, at least one, at least 2, at least 3, at least 4, at least 5 of the following features: , At least 6, and preferably all of the following features are to be met:

-The modified diene elastomer contains 2 silicon atoms and 1 nitrogen atom,

-The group comprising a nitrogen atom is a nitrogen atom substituted with a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical, in particular a methyl radical,

-The spacer group is a hexamethylene radical -(CH ₂ ) ₆ -,

-In the alkoxy group(s) replacing the silicon atom(s), the alkyl radical has 1 to 4 carbon atoms, preferably a methyl radical or an ethyl radical,

-At least 50% of the alkoxy functional groups substituting the silicon atom(s) are hydrolyzed to provide hydroxyl groups,

-The diene elastomer is a butadiene/styrene copolymer,

-The modified diene elastomer comprises a ground diene elastomer comprising 3 or more and 6 or less, preferably 5 or less, and even more preferably 4 or less branches.

A further subject of the invention is a rubber composition based on an elastomeric matrix comprising at least one reinforcing filler and at least one modified diene elastomer according to the invention.

The elastomer matrix may contain up to 100 phr of the modified diene elastomer according to the present invention. With respect to the reinforcing rubber composition, the term "modified diene elastomer according to the invention" is understood to mean a modified elastomer according to the invention as well as any mixture of at least two modified elastomers according to the invention.

According to an alternative form of the invention, the elastomeric matrix may also comprise at least one diene elastomer other than the modified diene elastomer according to the invention. Diene elastomers or diene elastomers other than the modified diene elastomers according to the present invention, whether modified, functionalized, coupled or star-branched, may be selected from diene elastomers commonly used in tires such as natural rubber or synthetic elastomers. I can. Diene elastomers or diene elastomers other than the modified diene elastomer according to the present invention may be present in 1 to 70 parts by weight per 100 parts of the modified diene elastomer according to the present invention.

According to another alternative form, the matrix consists solely of the modified diene elastomer according to the invention.

Any type of reinforcing filler known for its ability to reinforce rubber compositions that can be used in the manufacture of tires, for example carbon black or other reinforcing inorganic fillers other than carbon black, in particular silica, coupling agents combined in a known manner Alternatively, a mixture of these two types of fillers can be used.

According to a particularly advantageous alternative form of the invention, the reinforcing filler is primarily other than carbon black. That is, more than 50% by weight of at least one filler other than carbon black, in particular a reinforcing inorganic filler such as silica, based on the total weight of the filler; In fact, the reinforcing filler is even made exclusively of reinforcing inorganic fillers such as silica.

According to this other alternative form, if carbon black is also present, the carbon black can be used in an amount of less than 20 phr, more preferably less than 10 phr (e.g. between 0.5 phr and 20 phr, especially 1 to 10 phr). .

Preferably, the amount of reinforcing filler (such as carbon black and/or other reinforcing fillers such as silica) is between 10 phr and 200 phr, more preferably between 30 phr and 150 phr, and the optimal amount differs depending on the specific application targeted in a known manner. Do.

All carbon blacks used individually or in mixture form are suitable as carbon blacks, in particular blacks commonly used in tires or their treads ("tire grade" blacks). These carbon blacks can be used separately, commercially available, or used in any other form, for example as a support for some of the rubber additives used.

The reinforcing inorganic filler is, in the present invention, any other inorganic or mineral filler capable of reinforcing the rubber composition intended for tire manufacture by itself, regardless of color and origin (natural or synthetic), without meaning other than an intermediate coupling agent. Should be understood to mean; These fillers are generally characterized by the presence of hydroxyl groups on their surface in a known manner.

Mineral fillers of the siliceous type, preferably silica (SiO ₂ ), are particularly suitable as reinforcing inorganic fillers. The silica used is any reinforced silica known to the person skilled in the art, in particular the BET specific surface and also the CTAB specific surface both less than 450 m ² /g, preferably 30 to 400 m ² /g, in particular 60 m ² /g and 300 m ² / It may be any precipitated or fumed silica between g. Mention may also be made of the aluminum type, in particular mineral fillers of alumina (Al ₂ O ₃ ) or aluminum hydroxide (oxide), or else the strengthened titanium oxide described for example in US 6 610 261 and US 6 747 087. Reinforcing fillers of another nature when these reinforcing fillers are coated with a siliceous layer or otherwise require the use of a coupling agent to form a link between the filler and the elastomer, including functional sites, in particular hydroxyl moieties, on its surface. , In particular carbon black are also suitable as reinforcing fillers. Mention may be made, for example, of carbon black for tires as described in patent documents WO 96/37547 and WO 99/28380.

The physical state in which the reinforcing filler is provided is not critical whether or not in the form of powder, microbeads, granules or other beads. Of course, reinforcing inorganic fillers are also understood to mean mixtures of different reinforcing fillers, in particular highly disperse silicas as described above.

When silica is present in the composition as a reinforcing filler, it is possible to use organosilanes, in particular alkoxysilane polysulfides or mercaptosilanes, or else at least difunctional polyorganosiloxanes as coupling agents. In particular, silica/elastomer binders have been described in a number of documents, the best known being difunctional alkoxysilanes, such as alkoxysilane polysulfides.

In the composition according to the invention, it is understood that the amount of coupling agent is advantageously less than 20 phr, and it is generally preferred to use as little as possible. The content of the coupling agent is preferably between 0.5 phr and 12 phr. The presence of the coupling agent depends on the presence of the reinforcing inorganic filler. The content of the coupling agent is easily adjusted by a person skilled in the art according to the content of the reinforcing filler; The content of the coupling agent is typically on the order of 0.5% to 15% by weight relative to the amount of the reinforcing inorganic filler.

The rubber composition according to the invention improves the dispersion of the filler in the rubber matrix, lowers the viscosity of the composition, and reduces the raw material state in a more generally known manner, such as a coupling activator, a formulation for covering the filler, or a more generally known manner. Processing aids may also be included which enable the advantage of improving the processing capacity in, for example, hydrolysable silanes, such as alkylalkoxysilanes, polyols, polyethers, primary, secondary or tertiary Grade amines, or hydroxylated or hydrolyzable polyorganosiloxanes.

The rubber composition according to the invention may also comprise a reinforcing organic filler that can replace all or part of the carbon black or other reinforcing fillers described above. As an example of a reinforcing organic filler, functionalized polyvinyl organic as described in patent applications WO-A-2006/069792, WO-A-2006/069793, WO-A-2008/003434 and WO-A-2008/003435 Mention may be made of fillers.

The rubber composition according to the invention can also be used with general additives commonly used in elastomeric compositions intended for the manufacture of tires, for example pigments, protective agents, such as anti-ozone waxes, chemical ozone inhibitors or antioxidants, anti-fatigue agents. , Reinforcing or plastic resins, methylene acceptors (e.g. phenolic novolac resins) or methylene donors (e.g. HMT or H3M), for example those described in patent application WO 02/10269, sulfur or sulfur Crosslinking systems based on donors and/or peroxides and/or bismaleimide, vulcanization accelerators, vulcanization activators, adhesion promoters to non-rubber surfaces such as cobalt-based compounds, plasticizers, preferably naphthenic oils, paraffins Based oils, MES oils, TDAE oils, ether plasticizers, ester plasticizers, hydrocarbon resins with high Tg, preferably Tg greater than 30°C, for example patent applications WO 2005/087859, WO 2006/061064 and WO 2007/ Non-aromatic or very slightly aromatic plasticizers selected from the group consisting of hydrocarbon resins as described in 017060, and all or part of a mixture of these compounds.

Another subject of the invention is a method of making a rubber composition as described above.

The composition is prepared in a suitable mixer using the following two successive production steps well known to those skilled in the art: thermomechanical operation or kneading at high temperatures up to a maximum temperature between 110°C and 190°C, preferably between 130°C and 180°C. The first step of the ("non-productive" step) followed by the second step of mechanical work (the "productive" step) at a lower temperature, typically below 110° C., eg between 40° C. and 100° C., crosslinking during this finishing step The coupling system is incorporated.

The method according to the invention for preparing the rubber composition according to the invention comprises at least the following steps:

In one or more steps, in the elastomer matrix comprising the modified diene elastomer according to the invention, the components of the composition, ie the crosslinking system, and, in some cases, the basic constituents necessary for the rubber composition, except for the adhesion promoter, are at 110° C. And intimately mixing by kneading at a maximum temperature between 190°C and preferably between 130°C and 180°C to carry out the first stage of thermomechanical work (sometimes referred to as “non-productive” stage),

-The second stage of mechanical work is carried out at a temperature lower than the maximum temperature of the first stage, preferably at a temperature less than 110° C., during which the crosslinking system and, if necessary, an adhesion promoter are incorporated.

According to an alternative form of the present invention, the method for preparing the rubber composition comprises the step of preparing the modified diene elastomer according to the present invention as described above according to different synthetic methods.

The final composition thus obtained can subsequently be calendered, for example in the form of a sheet or slab, or it is also extruded to form a rubber profiled element which can be used, for example as a semi-finished product intended for tires. can do.

Another subject of the invention is a semi-finished product made of rubber comprising the rubber composition according to the invention.

Another subject of the invention is a tire in which at least one of the constituent members of the tire is a semi-finished product made of rubber comprising the rubber composition according to the invention.

The features of the present invention described above, and also other features, may be better understood by reading the description of several exemplary embodiments of the present invention, which are provided by way of illustration without limitation.

Example

Measurement method used

High resolution size exclusion chromatography (HR SEC)

The high-resolution SEC technique allows for the various populations of chains present in the polymer sample [1-branched (1b), 2-branched (2b), 3-branched (3b), 4-branched (4b), 5-branched (5b), 6 -Used to measure the weight percentage of the branch (6b)].

There is no specific treatment of the polymer sample prior to analysis. The polymer sample is simply dissolved in the elution solvent at a concentration of about 1 g/L. The solution is filtered through a filter with a porosity of 0.45 μm prior to injection.

The apparatus used is a Waters Alliance 2695 chromatography line. The eluting solvent is tetrahydrofuran, the flow rate is 0.2 ml/min, and the temperature of the system is 35°C. A set of three identical columns in series is used (Shodex, length 300 mm, diameter 8 mm). The number of theoretical plates in the column set exceeds 22,000. The volume of the solution of the injected polymer sample is 50 μl. The detector is a Waters 2414 differential refractometer and the software for using chromatographic data is a Waters Empower system.

The entity distribution (% 1b/2b/3b/4b/5b/6b) is determined by integrating the area under the curve for each chromatogram peak or, if the peaks are convoluted, to the shoulder, 1b + 2b + 3b + 4b + 5b + 6b is 100%.

Bis( Trimethoxysilylhexyl )-N-Methylamine Preparation

Bis(trimethoxysilylhexyl)-N-methylamine can be similarly prepared according to the methods described in the literature for compounds of similar chemical structure.

For example, methylamine (2.0M in methanol, 81.6 mmol) was added to pure 6-chlorohexyltrimethoxysilane (163.2 mmol) in a glass bottle. The entire mixture was stirred at reflux at 90° C. for 24 hours. Subsequently, the formed bis(trimethoxysilylhexyl)-N-methyl amine was separated and recovered.

Elastomeric Produce Example

Two 250 ml glass bottles (Steinie Bottle). After neutralizing impurities in the solution to be polymerized by adding n-butyllithium (n-BuLi), 2.09 ml of n-BuLi in methylcyclohexane at 0.084 mol/L was added. The polymerization was carried out at 50°C.

After 50 minutes, the degree of conversion of the monomers reaches 70%. This content was measured by weighing the dried extract under reduced pressure of 200mmHg at 140 ℃. At 0.071 mol/L, 0.82 ml of a bis(trimethoxysilylpropyl)-N-methylamine solution in methylcyclohexane was added to the solution of the living polymer (0.33 molar equivalent to Li) present in bottle 1, and 0.073 mol 0.80 ml of a solution of bis(trimethoxysilylhexyl)-N-methylamine in methylcyclohexane at /L was added to a solution of the living polymer (0.33 molar equivalent to Li) present in bottle 2. After reacting at 60° C. for 15 minutes, 1 ml of pure methanol was added to the 1st and 2nd bottles, and then the antioxidant 4,4'-methylenebis(2,6-di(tert-butyl)phenol) in toluene 1 ml of a solution containing an 80/20 g/L mixture of /N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine was added to the 1st and 2nd bottles. The thus treated polymer was separated from the solution by drying under reduced pressure and a stream of nitrogen at 60° C. for 12 hours.

HR SEC analysis was performed on the recovered finished product at the end of this drying step [D day], then the elastomer was subjected to ambient air (pressure of 100 kPa and between 40% and 70%) at an ambient temperature of 25°C. Relative humidity) for 15 days and then for 60 days after storage (D+15 and D+60, respectively).

The results are presented in Table 1.

Sample Functionalizing agent HR SEC D
Finished product
(% 1b/2b/3b/4b/5b/6b) HR SEC D+15
(% 1b/2b/3b/4b/5b/6b) HR SEC D+60
(% 1b/2b/3b/4b/5b/6b) One
(Control) (A) 10/11/47/32/0/0 10/6/33/31/12/8 10/1/25/31/11/22 2
(Invention) (B) 10/15/53/22/0/0 10/14/49/21/2/4 10/14/47/23/2/4

(A): Bis(trimethoxysilylpropyl)-N-methylamine

(B): Bis(trimethoxysilylhexyl)-N-methylamine

Regarding the control sample, Elastomer 1 was obtained by functionalization with bis(trimethoxysilylpropyl)-N-methylamine. According to the results presented in Table 1, the degree of 2 branches appears to decrease sharply at the same time as the degree of 3 branches. This decrease is accompanied by appearance and then an increase in the degree of highly branched entity (five and six branches). The formation of these entities is due to the condensation hydrolysis reactions that can occur between the two and three branches (since they are rich in hydrolysable/condensable functional groups), thus explaining their reduction/disappearance.

According to the results presented in Table 1, bis(trimethoxysilylpropyl)-N, showing a large change during storage in the distribution of two branching and three branching entities that benefit the formation of five branching and six branching entities. -Unlike comparative elastomer 1 obtained with methylamine, the elastomer 2 according to the invention obtained by functionalization with bis(trimethoxysilylhexyl)-N-methylamine, which hardly changes during storage, 5 It appears to represent the distribution of two branching and three branching entities that benefit the formation of four branching and six branching entities.

The relative stability of one branching entity is explained by the fact that this entity is compared to a non-functional dead polymer.

With regard to the most variable entity, diene elastomers modified using the molecules according to the invention in which the spacer group as a modifier is a linear saturated divalent aliphatic group of 5, 6 or 7 carbon atoms allows an increase in storage stability, such that these molecules To reduce the change in the macrostructure of the synthesized polymer.

Claims (26)

Molecule corresponding to formula I.
Formula I

In Formula I,
R independently of each other represent a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical,
G1 and G2 represent, independently of each other, a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms,
X represents a group containing at least one nitrogen atom,
m is an integer from 1 to 20. The molecule of claim 1, characterized in that m is 1. The method according to claim 1 or 2,
X group

Represents,
Y is a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical, or a C ₆ -C ₁₈ aryl radical, preferably a C ₆ Aryl radical, or trialkylsilyl radical, or a group

And R ₁ represents a linear or branched divalent hydrocarbon-based group having 1 to 18 carbon atoms, and A is a group comprising a nitrogen atom. The method according to claim 1 or 2,
X group

Represents,
G3 represents a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms,
R'' represents a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical,
Radicals R are independently of each other, C ₁ -C ₄ Represents an alkyl radical, preferably a methyl or ethyl radical,
A molecule, characterized in that it corresponds to formula I, wherein a is 0 or 1. The method according to claim 1 or 2,
A molecule, characterized in that X corresponds to formula (I) representing a group of formula (II).
Formula II

In Formula II,
R''' may be the same or different and represent a linear or branched divalent aliphatic C ₁ -C ₁₈ radical, preferably a methylene or ethylene radical. As a method for synthesizing a modified diene elastomer,
A living diene elastomer comprising at least one reactive end, and
A step of reacting a modifier containing at least two trialkoxysilyl groups, wherein the trialkoxysilyl groups are connected to each other by a group containing at least one nitrogen atom, and the bond between the silicon atom and the nitrogen atom is 5 carbon atoms, A modified diene elastomer comprising the step of reacting, wherein the alkoxy radical of the trialkoxysilyl type group has 1 to 4 carbon atoms, generated by a spacer group defined as a linear saturated divalent aliphatic group of 6 or 7 Method of synthesis. The method for synthesizing a modified diene elastomer according to claim 6, characterized in that the modifier corresponds to formula (I).
Formula I

In Formula I,
R independently of each other represent a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical,
G1 and G2 represent, independently of each other, a linear saturated divalent aliphatic group having 5, 6 or 7, preferably 6 carbon atoms,
X represents a group containing at least one nitrogen atom,
m is an integer from 1 to 20. The method for synthesizing a modified diene elastomer according to claim 7, characterized in that the modifier corresponds to formula I, wherein m is 1. The method of claim 7 or 8, wherein the modifier
X group

Represents,
Y is a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical, or a C ₆ -C ₁₈ aryl radical, preferably a C ₆ Aryl radical, or trialkylsilyl radical, or a group

And R ₁ represents a linear or branched divalent hydrocarbon-based group having 1 to 18 carbon atoms, and A represents a group containing a nitrogen atom, which corresponds to the formula I, a method for synthesizing a modified diene elastomer. The method of claim 7 or 8, wherein the modifier
X group

Represents,
G3 represents a linear saturated divalent aliphatic group having 5, 6 or 7, preferably 6 carbon atoms,
R'' represents a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical,
Radicals R are independently of each other, C ₁ -C ₄ Represents an alkyl radical, preferably a methyl or ethyl radical,
A method for synthesizing a modified diene elastomer, characterized in that it corresponds to the formula (I) of 0 or 1. The method of claim 7 or 8, wherein the modifier
A method for synthesizing a modified diene elastomer, characterized in that X corresponds to formula I representing a group of formula II.
Formula II

In Formula II,
R''' may be the same or different and represent a linear or branched divalent aliphatic C ₁ -C ₁₈ radical, preferably a methylene or ethylene radical. A modified diene elastomer obtained by the method according to any one of claims 6 to 11. A modified diene elastomer comprising at least n-functional branching units,
The branching unit is composed of a group containing at least two silicon atoms substituted with a branch of the elastomer and connected to each other by a group containing at least one nitrogen atom, wherein n is 1 or more, preferably 3 or more, 9 or less, preferably 6 or less, wherein the bond between the silicon atom and the nitrogen atom is caused by a spacer group defined by a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms, a modified diene elastomer. The modified diene elastomer according to claim 13, characterized in that it corresponds to formula III.
Formula III

In Formula III,
E represents a diene elastomer branch,
The radicals R independently of each other represent a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical,
G1 and G2 represent, independently of each other, a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms,
X represents a group containing at least one nitrogen atom,
i and j are each independently an integer of 0 to 3,
i+j is 1 or more and 6 or less, preferably 5 or less, even more preferentially 4 or less,
m is an integer from 1 to 20. 15. The modified diene elastomer according to claim 14, wherein m is 1. The method of claim 14 or 15,
X group

Represents,
Y is a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical, or a C ₆ -C ₁₈ aryl radical, preferably a C ₆ A modified diene elastomer, characterized in that it represents an aryl radical or a trialkylsilyl radical. The method of claim 14 or 15,
X group

Represents,
Y is the group

Represents,
R ₁ represents a linear or branched divalent hydrocarbon group having 1 to 18 carbon atoms,
A modified diene elastomer, characterized in that it is a group comprising a nitrogen atom. The method of claim 14 or 15,
A modified diene elastomer, characterized in that X represents a group of formula II.
Formula II

In Formula II,
R''' may be the same or different and represent a linear or branched divalent aliphatic C ₁ -C ₁₈ radical, preferably a methylene or ethylene radical. The method of claim 14 or 15,
m is 1,
X group

Represents a group containing at least one nitrogen atom selected from,
G3 represents a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms,
R" represents a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical,
The radicals R independently of each other represent a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical,
a is an integer of 0 or 1,
k is an integer from 0 to 3,
a+k is 3 or less,
However, i+j+k is 3 or more and 9 or less, preferably 8 or less, more preferentially 7 or less, and even more preferentially 6 or less, a modified diene elastomer, characterized in that it corresponds to Formula III. 20. Modified diene elastomer according to any one of claims 13 to 19, characterized in that at least 50% of the -OR functional groups substituting the silicon atom(s) are hydrolyzed to provide hydroxyl groups. 21. Modified diene elastomer according to any one of claims 14 to 20, characterized in that i+j is greater than 3 or 3. 21. A branched diene elastomer according to any one of claims 13 to 20, comprising at least 50% by weight, preferably at least 80% by weight, based on the total weight of the modified diene elastomer. Modified diene elastomer, characterized in that. 21. A branched diene elastomer according to any one of claims 13 to 20, comprising at least 30% by weight, preferably at least 40% by weight, based on the total weight of the modified diene elastomer. Modified diene elastomer, characterized in that. 14. The modified diene elastomer according to claim 13, wherein the spacer group is a hexamethylene radical -(CH ₂ ) ₆ -. At least one reinforcing filler, and
An elastomer matrix comprising the modified diene elastomer according to any one of claims 12 to 24.
Based on, rubber composition. A tire comprising the rubber composition according to claim 25.