KR102468899B1 - Compounds containing at least two trialkoxysilyl groups, their use as functionalizing agents for diene elastomers, modified diene elastomers and compositions containing the 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 the above formula I,
R, independently of each other, represent a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical,
G1 and G2 independently represent 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 this class of molecule as diene elastomer functionalization agent can significantly improve the stabilization of the macrostructure of diene elastomers modified in this way during storage.

Description

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

The present invention relates to a new class of molecules containing silicon atoms and nitrogen atoms. The present invention also relates to methods of using this class of molecules as functionalization agents for the purpose of modifying diene elastomers and thus modified diene elastomers. The invention also relates to a rubber composition containing said elastomer, which composition may be used in particular for the manufacture of tires.

As the need to save fuel and protect the environment becomes a priority, hysteresis is developed to allow processing of polymers in the form of rubber compositions that can be used in the manufacture of various semi-finished products involved in the formation of tires. It is desirable to produce polymers that are as low as possible and have good mechanical properties. A number of solutions have already been tested to achieve the goal of lowering hysteresis. In particular, mention should be made of modifying the structure of the diene polymer by compounds which introduce functional groups into the diene polymer at the end of the polymerization, with the aim of obtaining a good interaction of the modified polymer with the filler, whether carbon black or other reinforcing fillers. can In particular, it has been proposed to use functionalized diene polymers with silanol or alkoxysilane functional groups. A number of functionalizing agents containing one or more groups containing a silicon atom forming a silanol or alkoxysilane functional group at the synthetic end have been described in the literature.

For the purpose of further improving the effect of the functionalization of the diene elastomer on the properties of the rubber composition containing the diene elastomer, functionalization with an alkoxysilane or silanol functional group is combined with functionalization with another functional group, in particular containing nitrogen atoms. Combinations have also been suggested. Although the properties of the rubber composition are sometimes contradictory, this dual functionalization makes it possible to improve the compromise especially in terms of the properties of the rubber composition comprising the 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 improvements in the mechanical and dynamic properties of rubber compositions for tire applications, and in particular emphasize an increase in wet grip, an improvement in heat dissipation, an improvement in rolling resistance or otherwise an improvement in wear.

It has also 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 modifies their microstructure.

Without being bound by the above interpretation, the inventors believe that these modified elastomers exhibit instability upon storage as a result of hydrolysis and condensation reactions of alkoxysilyl functional groups, 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 non-hydrolyzable. The selection of these non-hydrolyzable groups reduces the likelihood of obtaining commercially or economically advantageous compounds, and also affects the reactivity of these compounds towards living polymers and thus the properties of the rubber composition comprising the functionalized elastomer. Crazy.

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

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

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

[Problem 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 down the change in the macrostructure, or even suppressing the change.

[Means of solving the problem]

An object of the present invention is that we have now demonstrated that the modification of a diene elastomer with a specific functionalizing agent is stable during storage, provided that it does not show significant changes in the macrostructure during storage for at least one month. achieved from

[Contents of the invention]

Accordingly, the subject of the present invention is a new class of molecules which, when used as functionalization agents, make it possible to obtain modified diene elastomers which do not exhibit any appreciable change in macrostructure during storage for at least one month. Molecules of this class contain at least two trialkoxysilyl groups in their molecular structure, said trialkoxysilyl groups being 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 carbon number It is caused by a spacer defined by a linear saturated divalent aliphatic group of 5, 6 or 7.

Another subject of the present invention is a process for the synthesis of modified diene elastomers wherein the 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, a specific functionalizing agent 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 for synthesizing a modified diene elastomer, including 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, in particular comprises, within the elastomeric structure, a branching unit comprising at least two silicon atoms interconnected by a group comprising at least one nitrogen atom, wherein the silicon atoms and Bonding between nitrogen atoms occurs by a spacer defined as a linear saturated divalent aliphatic group of 5, 6 or 7 carbon atoms.

Another subject 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 this specification, unless otherwise specifically indicated, all percentages (%) given are mass %. The abbreviation "phr" means parts by weight per hundred parts of elastomer present in the elastomer matrix, which elastomer matrix represents all elastomers present in the rubber composition.

Further, any interval of values denoted by the expression "between a and b" represents a range of values from greater than "a" to less than "b" (i.e., excluding limits a and b). ), any interval of values denoted by the expression "a to b (from a to b)" means a range of values extending from "a" to "b" (i.e., inclusive of the strict limits a and b). do). In the present specification, when an interval of values is indicated by the expression “a to b”, an interval indicated by the expression “between a and b” is also preferentially meant.

In this patent application, "predominantly" or "predominant" in relation to a compound means that the compound is predominant among compounds of the same type in the composition, i.e. most among compounds of the same type. It should be understood that it is meant to represent a large weight fraction. Thus, for example, the predominant elastomer is the elastomer that exhibits the greatest weight fraction relative to the total weight of the elastomers in the composition. In the same way, a "major" filler is the filler that exhibits the greatest weight fraction relative to the total weight of the formulated fillers of the composition. Further, the "major" functional entity of the modified diene elastomer is that which exhibits the largest weight fraction among the functionalized entities that make up the diene elastomer, relative to the total weight of the modified diene elastomer. In systems comprising only one compound of a particular type, the latter is key within the meaning of the present invention.

The expression "composition based on" is to be understood as used herein to mean a composition comprising a mixture of the various ingredients and/or reaction products in situ, and these basic ingredients (e.g. For example, some of the elastomers, fillers or other additives commonly used in rubber compositions intended for the manufacture of tires) may react with one another or at least partially react with one another during the various stages of manufacture of the composition intended for the manufacture of tyres. may be intended to react.

As used herein, the term "modified diene elastomer" refers to an entity (or macromolecule) resulting from a functionalization reaction using a compound containing at least six functional groups (alkoxy functional groups substituting silicon atoms) reactive towards the reactive ends of the diene elastomer. molecule), the compound comprising several heteroatoms comprising at least two silicon atoms and at least one nitrogen atom.

One skilled in the art knows that the modification reaction with an agent comprising at least one functional group reactive towards the living elastomer (in this case an alkoxy functional group carried by a silicon atom) is the linear entity of the modified elastomer, and at least three branches and modifications. functionalized (also referred to as coupled) at the ends of the chain and in the middle of the chain comprising as many branches as there are reactive functional groups carried by the functionalizing agent constituting the branched entity of the elastomer. It will be appreciated that this results in a mixture of entities (or macromolecules). Depending on the operating conditions, mainly the molar ratio of the functionalizing agent to the living chain, certain entities are present in less or more, or even predominantly, in the mixture.

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

In the present specification, the expression “branching unit” is understood to be 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 from which diene elastomer chain(s) emerge.

In the context of the present invention, it should be noted that the monomers used may be of fossil or biological origin. In the latter case, they are produced partly or wholly from biomass or they can be obtained from renewable starting materials produced from biomass.

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

Molecules according to the present invention most specifically correspond to formula (I).

Formula I

In the above formula I,

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

G1 and G2 independently represent 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

, 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 represents a C ₁ -C ₄ alkyl radical, or a C ₆ aryl radical, or a molecule representing 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 triethoxysilyl compounds trimethoxysilyl compounds, and the compounds bis(trimethoxysilylalkyl)-N-trimethylsilylamine and bis(triethoxysilylalkyl)-N-trimethylsilylamine, wherein the alkyl radical is C ₅ , C ₆ or C ₇ radical).

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

Represents, Y is a group

, R ₁ represents a linear or branched divalent hydrocarbon-based group having 1 to 18 carbon atoms, and A is a molecule that 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)amines, and trimethoxysilyl compounds corresponding to these triethoxysilyl compounds, wherein the alkyl radical is a C ₅ , C ₆ or C ₇ radical. 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 molecules representing, mention can be made, for example, of the compounds tris(triethoxysilylalkyl)amine and tris(trimethoxysilylalkyl)amine, wherein the alkyl radical is a C ₅ , C ₆ or C ₇ radical. have.

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

Formula II

In Formula II above,

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

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

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

According to a preferential alternative form of the present invention, which can be combined with the preceding alternative forms with respect to the functional group X and with respect to the functional groups G1 and G2, respectively, 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 present invention, the molecule according to the present invention is such that the radicals R represent a methyl or ethyl radical and X represents a group

, 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. 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 compounds bis(6-trimethoxysilylhexyl)-N-trimethylsilylamine and bis(6-tri Ethoxysilylhexyl)-N-trimethylsilylamine may be mentioned.

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

The molecules according to the invention described above can advantageously be used as functionalization agents with the aim of providing modified diene elastomers which do not exhibit any appreciable change in macrostructure during storage for at least one month.

Accordingly, another subject 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 containing at least two trialkoxysilyl groups with a specific function. 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 for synthesizing a modified diene elastomer, including the step of reacting, generated by a spacer group defined by.

The polymerization step according to the present invention can be carried out by anionic polymerization initiated by an organic compound of, for example, an alkali metal or an alkaline earth metal. According to another embodiment of the method of the present invention, this polymerization step may be chain polymerization by catalysis (following a coordination-insertion mechanism) using catalyst systems based on rare earth metals, titanium or other transition metals. Polymerization of at least one conjugated diene monomer according to these different embodiments results in an elastomeric chain having reactive sites at the chain ends. Depending on the polymerization method used, these sites are more or less reactive. Then, the commonly used terms are (pseudo-)living elastomers or (pseudo-)living chains.

Regarding anionic polymerization, the polymerization initiator may be any known mono- or polyfunctional anionic initiator. However, an initiator containing an alkali metal such as lithium is preferentially used. Suitable organolithium 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 those obtained from ethyllithium, n-butyllithium (n-BuLi) or isobutyllithium, or cyclic secondary amines such as pyrrolidine and hexamethyleneimine. It is lithium amide. Such anionic polymerization initiators are known to those skilled in the art.

Regarding chain polymerization by coordination catalysis, 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.

Polymerization can be carried out continuously or batchwise in a manner known per se. The polymerization is generally carried out at a temperature between 0°C and 110°C, preferably between 50°C and 100°C, or even between 70°C and 90°C. The temperature may remain constant throughout this step or may vary depending on the target characteristics of the synthesized elastomer. The polymerization process can be carried out in solution, in a more or less 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 anionic polymerization, which makes it possible to achieve a higher content of functionalized chains than that obtained with polymerization by coordination catalysis. Thus, preferentially, the process which is the subject of the present invention comprises the step of anionic polymerization of at least one conjugated diene monomer in the presence of an anionic polymerization initiator, in particular an initiator comprising carbon-lithium bonds.

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, examples 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. Preferentially, the conjugated diene monomer is 1,3-butadiene or 2-methyl-1,3-butadiene.

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

According to another alternative form of the process 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 containing 8 to 20 carbon atoms. As vinyl aromatic compounds the following are particularly suitable: styrene, ortho-, meta- or para-methylstyrene, α-methylstyrene, "vinyltoluene" commercial mixtures, para-(tert-butyl)styrene, methoxystyrene, vinyl. Mesitylene, divinylbenzene, vinyl naphthalene, etc., preferentially styrene.

Regarding the copolymerization of at least one conjugated diene monomer and at least one vinyl aromatic monomer, the proportion of each monomer is such that the obtained copolymer contains 20% to 99% by weight of diene units and 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 process of the present invention, the conjugated diene monomer may be copolymerized with one or more other ethylenically unsaturated monomers, in particular in addition to the conjugated diene monomer or the vinyl aromatic monomer. Among these ethylenically unsaturated monomers mention may therefore be made of ethylene, propylene, 1-butene, isobutylene, pentene, methylpentene or 1-hexene. Ethylene or propylene will be the preferred choice.

In order to refine the microstructure of the diene elastomer, modifiers and/or randomizers may optionally be added in suitable amounts. This is within the general knowledge of a person skilled in the art.

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

Polymerization of at least one conjugated diene monomer according to the present invention produces an elastomeric chain having reactive sites at the chain ends. According to one preferred embodiment, the polymerization in the context of the present invention is anionic and is carried out in the presence of a polymerization initiator. Then, the commonly used term is living elastomer or living chain. These living chains or living elastomers then react on the functionalizing agent during the functionalization step. The modifier contains at least one group reactive towards the reactive site of the elastomer, and in this case contains 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. Generally, the molar ratio of the group of agents reactive towards the living elastomer to the metal of the polymerization initiator is less than 5, especially in the range of 0.1 to 2. Thus, according to certain alternative forms of the present invention, the molar ratio of functionalization 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 functionalizing agent to metal of the polymerization initiator is greater than 0.5, greater than 0.65, preferentially greater than 1, or else ranges from 0.65 to 1.45. According to another alternative form of the invention, the molar ratio of functionalizing agent to metal of the polymerization initiator ranges from 0.25 to 0.35.

The conditions for adding the modifier to the elastomer and reacting the modifier with the elastomer are common in the context of anionic polymerization modification with aminated alkoxysilane compounds and are known to those skilled in the art. These conditions do not include any specific restrictions.

Modifiers are selected from the novel classes of molecules described above according to both their preferred alternative forms and aspects. In particular, the modifier is selected from molecules corresponding to Formula I according to both their preferred alternative forms and aspects.

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

a. 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, in the presence of an anionic initiator comprising carbon-lithium bonds 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. With the living diene elastomer obtained in the above step, the radicals R represent a methyl or ethyl radical, and X represents a group

, 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; reaction with a specific functionalizing agent selected from molecules that

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

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

A subject of the present invention is a modified diene elastomer comprising in particular at least n-functional branching units, said branching units comprising at least two groups substituted with branches of said elastomer and linked to each other by groups comprising at least one nitrogen atom. It consists of a group containing two 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 linearly saturated with 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 copolymers, in particular copolymers of butadiene with vinyl aromatic monomers or copolymers of butadiene with aliphatic monoolefins, isoprene copolymers and mixtures of these elastomers. It is selected from the group of diene elastomers consisting of. Such copolymers are more particularly butadiene/styrene copolymers (SBR), butadiene/ethylene copolymers (EBR), isoprene/butadiene copolymers (BIR), isoprene/styrene copolymers (SIR) and isoprene/butadiene/styrene copolymers ( SBIR). Among these copolymers, a butadiene/styrene copolymer (SBR) is particularly preferred.

Elastomers can be block, random, sequential, microsequential, and the like.

The diene elastomer can have any microstructure.

According to one preferred aspect of the present invention, the modified diene elastomer according to the present invention contains at least 2 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 present invention. According to these alternative forms, all or at least 50 mole percent of the alkoxy functional groups carried by the modified diene elastomer are hydrolyzed to provide hydroxyl groups. In particular, at least 80 mol%, in fact even 100%, of the alkoxy functional groups carried by the modified diene elastomer are hydrolyzed to give hydroxyl groups.

Alkyl radicals of alkoxy groups substituting silicon atoms 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 preferably methyl and ethyl.

According to the present invention, the branching unit comprises at least two silicon atoms, these silicon atoms 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 contains 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 feature related to the nature of the spacer groups 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 represent, independently of each other, a C ₁ -C ₄ alkyl radical, preferably a methyl or ethyl radical;

G1 and G2 independently represent a linear saturated divalent aliphatic group containing 5, 6 or 7 carbon atoms, preferably 6 carbon atoms,

X represents a group containing at least one nitrogen atom,

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

i+j is greater than or equal to 1 and less than or equal to 6, preferably less than or equal to 5, and even more preferably less than or equal to 4;

m is an integer from 1 to 20, preferably an integer of 1.

Advantageously, in Formula III, i and j are such that i+j is greater than or equal to 3 and less than or equal to 6.

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 an aryl radical, or a trialkylsilyl radical, or a group

, 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 above,

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

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

m is 1,

를 나타내고, X is a group

represents,

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

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

the radicals R represent, independently of each other, 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 less than or equal to 3;

provided that i+j+k corresponds to Formula III, which is greater than or equal to 1 and less than or equal to 9, preferably less than or equal to 8, more preferably less than or equal to 7, and even more preferably less than or equal to 6.

를 나타내고, Y는 C₁-C₄ 알킬 라디칼, 바람직하게는 메틸 또는 에틸 라디칼, 특히 메틸 라디칼을 나타내는 화학식 III에 상응한다. According to the present invention, the modified diene elastomer preferentially corresponds to formula III wherein m is 1. Even more preferentially, the modified diene elastomer preferentially has m equal to 1 and X to a group

and Y corresponds to Formula III, which represents 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 present invention contains at least 50% by weight, preferably at least 80% by weight of the branched diene elastomer comprising four branches, relative to the total weight of the modified diene elastomer. include

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

Various preferred alternative forms and aspects relating to the properties of the modified diene elastomer, alkoxysilane functional groups, spacer groups and groups comprising at least one nitrogen atom may be combined with each other according to their compatibility.

According to an advantageous alternative form of the invention, the elastomeric structure comprises branching units comprising at least two silicon atoms linked to one another by groups comprising at least one nitrogen atom, wherein the bonds between the silicon atoms and the nitrogen atoms are carbon atoms. The modified diene elastomer resulting from a spacer group defined by 5, 6 or 7 linearly saturated divalent aliphatic groups has at least one, at least two, at least three, at least four, at least five of the following characteristics: , at least six, and preferably all of the following characteristics:

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

- the group comprising a nitrogen atom is a nitrogen atom substituted by 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) substituting 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 replacing the silicon atom(s) are hydrolyzed to give hydroxyl groups;

- the diene elastomer is a butadiene/styrene copolymer,

- the modified diene elastomer comprises a ground diene elastomer comprising at least 3 and no more than 6, preferably no more than 5, even more preferably no more than 4 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 elastomeric matrix may comprise up to 100 phr of the modified diene elastomer according to the present invention. In relation to the reinforced rubber composition, the term "modified diene elastomer according to the present invention" is understood to mean a modified elastomer according to the present invention as well as any mixture of at least two modified elastomers according to the present 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. The diene elastomer or diene elastomers other than the modified diene elastomer 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. can The diene elastomer or diene elastomers other than the modified diene elastomer according to the present invention may be present in an amount of 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 exclusively of the modified diene elastomer according to the invention.

Reinforcing fillers of any type known for their ability to reinforce rubber compositions which can be used in the manufacture of tires, e.g. carbon black or other reinforcing inorganic fillers other than carbon black, in particular silica combined in a known manner, coupling agents Alternatively, mixtures of these two types of fillers may be used.

According to a particularly advantageous alternative form of the invention, the reinforcing filler is primarily other than carbon black. That is, it contains more than 50% by weight of one or more fillers other than carbon black, particularly reinforcing inorganic fillers such as silica, based on the total weight of the fillers; In practice the reinforcing fillers even consist exclusively of reinforcing inorganic fillers such as silica.

According to this other alternative form, if carbon black is also present, carbon black may 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 between 1 and 10 phr). .

Preferably, the amount of reinforcing filler (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, with the optimal amount varying according to the specific application targeted in a known manner. do.

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

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

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 having both a BET specific surface and also a CTAB specific surface of less than 450 m ² /g, preferably 30 to 400 m ² /g, in particular 60 m ² /g and 300 m ² /g g of any precipitated or fumed silica. Mention may also be made of mineral fillers of the aluminum type, in particular of alumina (Al ₂ O ₃ ) or aluminum hydroxide (oxide), or else strengthened titanium oxide as described for example in US Pat. No. 6,610,261 and US Pat. No. 6,747,087. Reinforcing fillers of another nature, when these reinforcing fillers are covered with a siliceous layer or otherwise contain functional sites on their surface, in particular hydroxyl sites, requiring the use of a coupling agent to form a link between the filler and the elastomer. , especially carbon black, is also suitable as a reinforcing filler. Mention may be made, for example, of carbon blacks 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 in the form of powders, microbeads, granules or else beads. Of course, reinforcing inorganic fillers are also understood to mean mixtures of different reinforcing fillers, in particular highly dispersible silicas as described above.

When silica is present in the composition as reinforcing filler, organosilanes, in particular alkoxysilane polysulfides or mercaptosilanes, or else at least difunctional polyorganosiloxanes may be used as coupling agents. Silica/elastomeric binders in particular have been described in a number of publications, the best known being difunctional alkoxysilanes, such as alkoxysilane polysulfides.

In the composition according to the present invention, the amount of coupling agent is advantageously less than 20 phr, and it is understood that it is generally desirable to use as little as possible. The amount of coupling agent is preferably between 0.5 phr and 12 phr. The presence of coupling agents depends on the presence of reinforcing inorganic fillers. 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 amount of coupling agent is typically on the order of 0.5% to 15% by weight relative to the amount of reinforcing inorganic filler.

The rubber composition according to the present invention, in addition to the coupling agent, is a coupling activator, an agent for covering the filler, or, in a more generally known manner, improves the dispersion of the filler in the rubber matrix, lowers the viscosity of the composition, and reduces the raw material state It may also include processing aids which enable the advantage of improving the processability in the process, these agents are for example hydrolysable silanes such as alkylalkoxysilanes, polyols, polyethers, primary, secondary or tertiary tertiary amines, or hydroxylated or hydrolysable polyorganosiloxanes.

The rubber composition according to the present invention may also contain reinforcing organic fillers which may replace all or part of the carbon black or other reinforcing fillers described above. As examples of reinforcing organic fillers, functionalized polyvinyl organics as described in patent applications WO-A-2006/069792, WO-A-2006/069793, WO-A-2008/003434 and WO-A-2008/003435 Fillers may be mentioned.

The rubber composition according to the invention may also contain general additives, such as pigments, protectants, such as anti-ozone waxes, chemical anti-ozonants or antioxidants, anti-fatigue agents usually used in elastomeric compositions intended for the manufacture of tires. , reinforced or plastic resins, methylene acceptors (eg phenolic novolak resins) or methylene donors (eg 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 bismaleimides, 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 a high Tg, preferably with a Tg greater than 30° C., for example patent applications WO 2005/087859, WO 2006/061064 and WO 2007/ 017060, a non-aromatic or very slightly aromatic plasticizer selected from the group consisting of hydrocarbon resins, and all or part of mixtures of such compounds.

Another subject of the present invention is a process for preparing a rubber composition as described above.

The composition is prepared in a suitable mixer using two successive manufacturing steps well known to those skilled in the art: thermomechanical working or kneading at high temperature to a maximum temperature between 110°C and 190°C, preferably between 130°C and 180°C. a first step (“non-productive” step) followed by a second step (“productive” step) of mechanical operation at a lower temperature, typically less than 110° C., for example between 40° C. and 100° C. (“productive” step), crosslinking during this finishing step A binding system is incorporated.

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

- in at least one step, in an elastomer matrix comprising the modified diene elastomer according to the invention, the components of the composition, i.e. the crosslinking system and, if appropriate, the basic constituents necessary for the rubber composition, with the exception of the adhesion promoter, are brought to 110° C. and 190° C., preferably between 130° C. and 180° C., the first stage of thermomechanical operation (sometimes referred to as the “unproductive” stage) by intimate incorporation by kneading, followed by

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

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

The final composition thus obtained can subsequently be calendered, for example into sheet or slab form, or it can also be extruded to form a rubber profiled element which can be used as a semifinished product intended, for example, 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 tire's constituent elements is a semifinished product made of rubber comprising the rubber composition according to the invention.

The features of the invention described above and also other features may be better understood upon reading the following description of several practical embodiments of the invention, given by way of example and without limitation.

Example

Measurement method used

High Resolution Size Exclusion Chromatography (HR SEC)

High-resolution SEC techniques can be used to analyze the diverse populations of chains present in polymer samples [1-branch (1b), 2-branch (2b), 3-branch (3b), 4-branch (4b), 5-branch (5b), 6 - branch (6b)] is used to determine the weight percentage.

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

The instrument used is a Waters Alliance 2695 chromatography line. The elution 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 to use the 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, integrating up to the shoulder, 1b + 2b + 3b + 4b + 5b + 6b is 100%.

bis( trimethoxysilylhexyl ) Preparation of -N-methylamine

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

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

elastomeric Produce Example

94.0 ml (72.4 g) of methylcyclohexane, 11.6 ml (7.5 g) of butadiene, 2.5 ml (2.3 g) of styrene and 0.78 ml of a solution of tetrahydrofuran in methylcyclohexane at 0.73 mol/L were mixed in two 250 ml glass bottles (Steinie bottle) was introduced. After adding n-butyllithium (n-BuLi) to neutralize impurities in the solution to be polymerized, 2.09 ml of n-BuLi in methylcyclohexane was added at 0.084 mol/L. Polymerization was carried out at 50 °C.

After 50 minutes, the conversion of monomer reaches 70%. This content was determined by weighing the dried extract at 140° C. under reduced pressure of 200 mmHg. 0.82 ml of a solution of bis(trimethoxysilylpropyl)-N-methylamine in methylcyclohexane at 0.071 mol/L was added to the solution of living polymer (0.33 molar equivalent relative 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 the solution of the living polymer (0.33 molar equivalent relative to Li) present in bottle #2. After reacting at 60°C for 15 minutes, 1 ml of pure methanol was added to bottles #1 and #2 followed by 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 bottles #1 and #2. The thus treated polymer was isolated from solution by drying under reduced pressure and nitrogen stream at 60° C. for 12 hours.

HR SEC analysis was performed on the finished product recovered at the end of this drying step [day D], then the elastomer was placed in ambient air at an ambient temperature of 25 °C (at a pressure of 100 kPa and between 40 and 70%). relative humidity) for 15 days and then for 60 days (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 group) (A) 10/11/47/32/0/0 10/6/33/31/12/8 10/1/25/31/11/22 2
(the present 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 seems to decrease rapidly simultaneously with the degree of 3 branches. This decrease is accompanied by an appearance followed by an increase in the degree of highly branched entities (5 and 6 branches). The formation of these entities is due to condensation hydrolysis reactions that can occur between the 2 and 3 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, which exhibits large changes during storage in the distribution of 2- and 3-branched entities favoring the formation of 5- and 6-branched entities. In contrast to comparative elastomer 1 obtained with methylamine, elastomer 2 according to the invention obtained by functionalization with bis(trimethoxysilylhexyl)-N-methylamine has a 5 It appears to represent a distribution of 2 branched and 3 branched entities favoring the formation of two branched and 6 branched entities.

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

With respect to the entity that varies the most, diene elastomers modified using 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 allow an increase in storage stability, allowing such molecules to reduce the change in the macrostructure of the synthesized polymer.

Claims (26)

A molecule corresponding to Formula I.
Formula I

In the above formula I,
R independently of one another represents a C ₁ -C ₄ alkyl radical, or a methyl or ethyl radical;
G1 and G2 independently represent a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms,
X is a group

, Y represents a C ₁ -C ₄ alkyl radical, or a methyl or ethyl radical;
m is an integer of 1; As a method for synthesizing a modified diene elastomer,
a living diene elastomer comprising at least one reactive end, and
A method for synthesizing a modified diene elastomer comprising reacting a modifier corresponding to formula (I).
Formula I

In the above formula I,
R independently of one another represents a C ₁ -C ₄ alkyl radical, or a methyl or ethyl radical;
G1 and G2 independently represent a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms or a linear saturated divalent aliphatic group having 6 carbon atoms,
X is a group

, Y represents a C ₁ -C ₄ alkyl radical, or a methyl or ethyl radical;
m is an integer of 1; A modified diene elastomer corresponding to Formula III.
Formula III

In Formula III,
E represents a diene elastomer branch,
the radicals R represent, independently of each other, a C ₁ -C ₄ alkyl radical, or a methyl or ethyl radical;
G1 and G2 independently represent a linear saturated divalent aliphatic group having 5, 6 or 7 carbon atoms,
X is a group

, Y represents a C ₁ -C ₄ alkyl radical, or a methyl or ethyl radical;
i and j are independently of each other an integer from 0 to 3,
i+j is 1 or more and 6 or less, 1 or more and 5 or less, or 1 or more and 4 or less;
m is an integer of 1; 4. The modified diene elastomer of claim 3, characterized in that at least 50% of the -OR functional groups substituting the silicon atom(s) are hydrolyzed to provide hydroxyl groups. The modified diene elastomer according to claim 3 or 4, characterized in that it comprises at least 50% by weight of the branched diene elastomer comprising four branches, based on the total weight of the modified diene elastomer. The modified diene elastomer according to claim 3 or 4, characterized in that it comprises at least 30% by weight of the branched diene elastomer comprising three branches, based on the total weight of the modified diene elastomer. at least one reinforcing filler, and
An elastomeric matrix comprising the modified diene elastomer according to claim 3 or 4
A rubber composition based on. A tire comprising the rubber composition according to claim 7. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete