WO2015101478A1 - Method for the continuous synthesis of a functionalised diene elastomer - Google Patents

Abstract

The invention relates to a method for the continuous synthesis of a functionalised high-cis diene elastomer, characterised in that it comprises the simultaneous steps of: continuous polymerisation in a highly concentrated medium, or bulk, of at least one diene monomer in the presence of a catalytic coordination system, until at least 60% conversion is achieved in a polymerisation reactor dimensioned such that the standard deviation of the distribution function of the residence time in the reactor is greater than the average residence time divided by 2√3; continuous functionalisation of the pseudo-living elastomer obtained from the polymerisation, by reaction with a functionalisation agent in a mixer, for example of the self-cleaning type. The synthesis method, for use in a highly concentrated medium, offers increased productivity, in particular allowing a high conversion rate of up to 100% and functionalisation rates of at least 70% to be achieved, as well as allowing performance flexibility.

Description

 PROCESS FOR THE CONTINUOUS SYNTHESIS OF AN ELASTOMER

 FUNCTIONALIZED DIENIC.

The present invention relates to a method of synthesis in a concentrated medium of modified diene elastomers with a high degree of functionalization. The invention applies in particular to the continuous production of modified diene elastomers.

Since fuel savings and the need to preserve the environment have become a priority, it is desirable to produce mixtures with good mechanical properties and as low a hysteresis as possible so that they can be used in the form of fuel compositions. rubber suitable for the manufacture of various semi-finished products used in the composition of tires.

To achieve the goal of lower hysteresis, many solutions have already been tested. In particular, mention may be made of modifying the structure of the diene polymers and copolymers by means of functionalising agents in order to obtain a good interaction between the polymer thus modified and the filler, whether it be black carbon or other reinforcing filler.

 There is a vast literature concerning the functionalization of polymers obtained by anionic polymerization. Functionalization can take place either during the initiation of polymerization by means of an initiator bearing the function to be incorporated in the elastomeric chain, or during a post-polymerization reaction by means of a functionalization agent. Agents for introducing all kinds of functions within the polymer are known to those skilled in the art and widely described.

 The anionic polymerization makes it possible to control to a certain extent the microstructure of the synthesized polymers. However, it is not possible by this type of polymerization to synthesize high cis content polymers.

 High cis content polymers are essentially prepared by coordination catalysis polymerization. There is also a very extensive literature dealing with this type of catalysis.

The functionalization of these polymers with a high cis content is less widespread because of the nature of the catalytic systems used. Some authors have described the functionalization of polymers obtained by coordination catalysis. Mention may especially be made of the documents WO 0134658 A1, EP 1,939,221 A1 and EP 1,873,168 A1. Some mention high levels of functionalization, greater than 75%, for polymers obtained by mass or semi-mass polymerization (EP 1,939,221 A1)

Nevertheless all these documents deal with discontinuous polymerization (or batch in English). If it is rapidly evoked in EP 1,939,221 A1 with reference to WO2005087824, the possibility of carrying out the method described continuously, the conversion rates are low. In WO2005087824, the polymerization is conducted in a first reactor to a conversion level of at most 20%. The polymer is discharged and transferred to a second reactor in which devolatilization can be carried out immediately. The limitation to a low conversion rate of 20% leads to a low productivity of this process. In addition, the unconverted monomer must be extracted and processed for reintroduction into the first reactor. This treatment is done on large volumes of unconverted monomer. This aspect of the process makes it unattractive because of its energy and economic impact on the cost of the process.

 It can be seen that in the past, the processes for modifying a high cis diene polymer are mainly carried out batchwise at the end of the coordination catalysis polymerization. However, such a batch process is not always productive and sufficiently competitive and economical for industrial production.

Furthermore, in order to enhance the economic interest of the polymerization, it may be advantageous to use a reduced amount of solvent. The advantages of mass or semi-mass polymerization (also called highly concentrated medium) are various. For example, the size of the equipment, in particular those outside the reaction part, is reduced because of the small amount of solvent used. This reduces investment costs. In addition, this reduction or removal of the solvent in fact leads to a decrease in the amount of energy (in the form of steam for removal of the solvent by steam stripping) to separate the elastomer from the solvent, as well as a decrease in the flow of solvent to be treated. All these characteristics lead to a reduction in the energy costs of the polymerization process. Moreover, the amount of catalyst is generally decreased, which reduces the cost of raw materials.

However, it is a major disadvantage of mass or semi-mass polymerization. This results in the appearance of a physical phenomenon that could degrade the nature of the polymer obtained and lead to uncontrollable situations in an industrial production. Indeed, the vaporization of a part of the liquid monomer, under the effect of the energy of the polymerization reaction, leads, from a certain polymer concentration in the reaction medium, excessive expansion of the reaction medium. Under such operating conditions, it is no longer possible to control the temperature of the reaction and the polymer may be denatured. This is the reason why some authors prefer low conversion rates to avoid this phenomenon, for example in US 3,770,710 or in WO2005087824.

 The technical problem to be solved by the invention is to have a competitive, economical and flexible synthesis process that is adaptable to industrial production, making it possible to produce a polymer with a high functionalized cis content.

An object of the invention is to provide a method for producing a high cis functionalised polymer having a high degree of functionalization.

 Another objective of the invention is to provide a method for synthesizing, in a highly concentrated medium, high functionalized cis-diene polymers which, in addition, have increased productivity while avoiding the phenomenon of expansion of the reaction medium and thus allowing flexibility in the conduct of the process especially in a wide range of temperatures.

 The present invention solves the technical problem and achieves these objectives in that it proposes a continuous process, particularly suitable for economically interesting industrial production with increased competitiveness. The invention proposes a continuous process for the synthesis of a functionalized diene polymer comprising a continuous polymerization step in a highly concentrated medium by coordination catalysis of at least one diene monomer and a step of continuous functionalization of the pseudo polymer. -vivant obtained.

 The invention makes it possible to improve the conditions of polymerization of conjugated dienes in a highly concentrated medium in order to be able to reach high conversion rates, without the appearance of an expansion phenomenon of the reaction medium.

 The invention also makes it possible to achieve high levels of functionalization on elastomers with a high cis content.

 The invention also provides the energy and environmental advantages of polymerization in a highly concentrated medium and the possibility of carrying out the process over a wide range of reaction temperatures.

Thus, the subject of the invention is a process for the continuous synthesis of a modified diene elastomer comprising a mass or semi-mass polymerization step in which High-cis pseudo-living diene elastomer is synthesized and a functionalization or modification step in which the pseudo-living diene elastomer reacts with a specific functionalising agent.

 The invention also relates to an installation for implementing such a method.

The first subject of the invention is a process for continuously synthesizing a functionalized diene elastomer comprising the following simultaneous steps,

 related to polymerization:

 a) continuously introducing into a polymerization reactor equipped with a gas phase and equipped with at least one stirring device and a discharge device, at least one

 i. a catalytic system of coordination,

 ii. at least one conjugated diene monomer to be polymerized, and, iii. from 0% to 70% by weight of an organic solvent, calculated with respect to the total monomer (s) mass and solvent;

 b) continuously polymerizing the monomer (s), by implementing the means necessary to achieve a conversion of at least 60% at the limit of the first third of the reaction volume of the polymerization reactor;

 c) stirring the polymerization medium by the continuous movement of at least one stirring member around a rotary axis;

 d) continuously discharging the pseudo-living elastomer paste resulting from the polymerization;

 the standard deviation of the residence time distribution function in the polymerization reactor being greater than the average residence time divided by 2Λ / 3, related to functionalization:

 e) continuously feed this paste to a mixer having a gas phase, a stirring device to at least one stirring device and a discharge device;

f) continuously introducing into the kneader a functionalizing agent corresponding to the formula A-R 1 -B with A denoting a group capable of reacting on the reactive end of the pseudo-elastomer; R 1 denotes an atom or a group of atoms forming a bond between A and B, and B denotes a function capable of reacting with a reinforcing filler;

 g) continuously functionalizing the pseudo-living elastomer by reaction with the functionalization agent in said kneader;

 h) continuously discharging the functionalized elastomer paste from the previous step;

 i) recovering the functionalized diene elastomer.

 Inasmuch as the process according to the invention proceeds continuously, it should be understood that steps (a) to (i) take place simultaneously once the polymerization reactor has been supplied.

In the present description, the terms "highly concentrated medium" and "mass or semi-mass" are used interchangeably to have the same meaning.

In the present description, the terms "solvent" and "diluent" are used interchangeably to have the same meaning.

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

In the present description, the term "high cis content" or "high cis ratio" in relation to the elastomer means a molar ratio of 1,4-cis units of at least 95% by relative to the elastomer.

 In the present description, the term "pseudo-living" in relation to the elastomer, means that the elastomer has all or part of these reactive chain ends, especially vis-à-vis functionalising agents.

 In the present description, the rate of functionalization, which is an average degree of functionalization, must be understood as the average percentage of functionalized elastomer chains.

It should be noted that the combination of the flow characteristics and the conversion constitutes one of the essential elements of the invention which enables the continuous polymerization process to respond to the technical problem posed for the polymerization in a highly concentrated medium, adaptable to a economically industrial production advantageous with satisfactory productivity, more particularly by avoiding the phenomenon of expansion of the reaction medium.

 According to a particular implementation of the synthesis method of the invention, the polymerization is carried out continuously with a quantity of solvent not exceeding 70% by weight of the total mass of monomer (s) and solvent, the quantity of a solvent which may be, for example, at least 10% by weight, or even at least 30% by weight, and at most 60% by weight, or even at most 55% by weight of the mass total monomer (s) and solvent. According to another embodiment of the invention, the polymerization is carried out without addition of polymerization solvent.

The choice of the polymerization reactor is, because of these possibilities of implementation, a particularly important aspect of the process according to the invention. Indeed, it is desired to polymerize monomers in highly concentrated media. According to the invention, by highly concentrated media, it is meant a concentration of monomer (s) in the solvent + monomer (s) mixture of at least 30% by weight, this concentration can reach 100% by weight in the absence of solvent . In addition, it is desired to polymerize until obtaining high conversion rates in the limit of the first third of the reaction volume of the polymerization reactor of at least 60% and up to 100%.

The viscosity of the polymerization medium consisting essentially of the monomers, the elastomer and optionally the solvent can reach high values. The inherent viscosity of the diene elastomer depends on its nature. It has a minimum value of at least 1.5 dl / g, or even at least 4 dl / g, especially for polyisoprenes obtained by coordination catalysis. However, the inherent viscosity preferably does not exceed 10 dl / g or 7 dl / g. The inherent viscosity is determined according to the method described in Appendix 1.

The stirring within the polymerization reactor must ensure the mixing of this highly viscous medium to allow the synthesis of a polymer of constant and homogeneous quality. In addition to the compatibility with high viscosities, the reactor must be suitable for use in polymerizing the monomer (s) in a continuous mode and allow flow in a highly concentrated medium, or even in mass, such as the standard deviation of the function. of residence time distribution in the polymerization reactor is greater than the average residence time divided by 2Λ / 3.

The stirring mobile allows continuous stirring of the reaction medium. It can be of varied form and is adapted to the reactor technology. Many types of agitation mobiles can be found commercially. By way of example, the stirring device may be a sigma (or "Z") type or other type of blade as described in the David B. Todd book, Mixing of Highly Viscous Fluids, Polymers, and Pastes, Handbook of Industrial Mixing: Science and Practice, Paul EL, Atiemo-Obeng VA, and SM Kresta, Editors. 2004, John Wiley and Sons. Page 998, Page 1021.

 When the reactor is equipped with at least two agitating mobiles, these can be counter-rotating or co-rotating. In addition, they can be tangential or nested.

According to certain configurations, the polymerization reactor is equipped with a stirrer. Thus, this type of reactor may be formed of a vessel, a stirring device and a discharge device. For example, mention may be made of the reactor marketed by the company LIST AG under the name single-arm kneader or single-shaft kneader, as reactor suitable for the invention.

 According to other configurations, the polymerization reactor is equipped with two stirring rods.

 According to the configurations described above, the polymerization reactor may be formed of a tank, its stirring system and a discharge device.

 According to preferred configurations, the polymerization reactor is more particularly Z-arm kneader technology. By Z-arm kneading technology, more particularly is meant a mixer or kneader formed of a tank equipped with two Z-shaped arms, each driven by independently about a rotary axis, preferably horizontal. The two Z-arms are then preferably moved in counter-rotating rotation so as to fill the emptying device at the bottom of the tank.

 By way of example, this reactor according to the invention is marketed under various names such as:

 - Mixers sigma blades - discharge screw, or in English "sigma blades mixer-discharge screw type", marketed by Battaggion SPA,

extruder-kneaders, marketed by Aachener Misch-und Knetmaschinenfabrik Peter Kupper GmbH & Co. KG, double Z mixers with extrusion screws or in English "double-z-kneader" with extrusion screw ", marketed by Hermann Linden Maschinenfabrik GmbH & Co. KG., Extruder mixers, sold by Aaron Process Equipment Company.

 The polymerization reactor is provided with a gas phase allowing the evacuation of the polymerization heat by vaporization of a part of the reaction medium. The volume ratio of the gas phase to the reaction medium depends on the type of reactor used and its determination is within the reach of those skilled in the art.

 According to one embodiment of the invention, the polymerization is carried out in bulk. In this case, there is no addition of polymerization solvent.

 According to other embodiments of the invention, the polymerization is carried out in semi-mass. The medium then comprises an inert hydrocarbon polymerization solvent, preferably aliphatic or alicyclic low molecular weight, especially for environmental reasons. By way of example, mention may be made of n-pentane, isopentane and isoamylenes (2-methyl-2-butene, 2-methyl-1-butene and 3-methyl-1-butene). dimethylbutane, 2,2-dimethylpropane (neopentane), n-heptane, n-octane, isooctane, cyclopentane, cyclohexane, n-hexane, methylcyclopentane and methylcyclohexane, as well as these compounds, n-pentane being particularly preferred. Aromatic hydrocarbons, for example benzene or toluene, may also be mentioned as solvents.

 The solvent can be introduced directly into the reactor. It may also be mixed beforehand with at least one of the other components introduced into the polymerization reactor, in particular with the monomer (s) to be polymerized. This last option constitutes a preferential implementation according to the invention.

 According to the process of the invention, at least one conjugated diene monomer is polymerized.

By conjugated diene monomer is meant a conjugated diene monomer having from 4 to 16 carbon atoms. As conjugated dienes 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-di (C ₁ -C ₅ alkyl) -1,3-butadiene, such as, for example, 2,3-dimethyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2-methyl-3-ethyl-1,3-butadiene, 2-methyl-3-isopropyl-1,3 -butadiene, phenyl-1,3-butadiene, 1,3-pentadiene, 2,4-hexadiene, myrcene etc.

According to implementations of the process of the invention, the conjugated diene monomer may be copolymerized with one or more conjugated diene monomers. According to an implementation of the process of the invention, the conjugated diene monomer may be introduced in the form of a petroleum fraction comprising the monomer or monomers to be polymerized.

 The choice of monomers is dictated by the desired polymer. The coordination catalysis polymerization is carried out using a catalytic system based on a rare earth metal, titanium or other transition metal.

 In the context of this coordination catalytic chain polymerization, a catalytic system based on rare earth metal or titanium is used.

Such catalytic systems are amply described in the literature.

By way of example, such a catalytic system may be prepared based on at least:

 an organic rare earth salt,

 an alkylating agent

and optionally,

 - a halogen donor and / or

 a conjugated diene monomer of preformation.

 By the expression "based on" used to define the constituents of the catalytic system is meant the product or the reaction products of these constituents after premixing of all or part of the constituents, or, where appropriate, after pre-forming and / or aging of the catalytic system or the product or products of the in situ reaction of these constituents.

 The catalyst system can be prepared batchwise or continuously. According to an implementation of the method of the invention, upstream of the polymerization reactor, a continuous synthesis system of the catalytic system continuously feeds the polymerization reactor. The catalytic system can be introduced directly into the reactor or be premixed with at least one of the other components that supply the polymerization reactor.

 According to the invention, the term "rare earth" is understood to mean a metal chosen from yttrium, scandium and lanthanides, metals having an atomic number ranging from 57 to 71 inclusive in the periodic table of Mendeleyev elements. Preferably, the rare earth metal is chosen from lanthanides, neodymium being more particularly preferred.

By organic salt of a rare earth metal is meant, for example, tris (carboxylates), tris (alcoholates), tris (acetylacetonates) or tris (organophosphates) of rare earth. When the rare earth organic salt is a rare earth tris (carboxylate), the carboxylate can be chosen from linear or branched aliphatic carboxylic acid esters having 6 to 16 carbon atoms in the linear chain, and the esters aromatic carboxylic acids having 6 to 12 carbon atoms, substituted or unsubstituted. By way of example, mention may be made of neodecanoate (versatate), octoate, hexanoate, linear or branched, or naphthenate, which may or may not be substituted. Of these, rare earth 2-ethylhexanoate, naphthenate or neodecanoate (versatate) is particularly preferred.

When the organic rare earth salt is a rare earth tris (alcoholate), the alcoholate may be chosen from the alcoholates of an alcohol or a polyol derived from an aliphatic or cyclic hydrocarbon and in particular from an aliphatic hydrocarbon , linear or branched, having 1 to 10 carbon atoms in the linear chain, more particularly 4 to 8 carbon atoms. For example, neo-pentanolate may be mentioned.

 When the organic rare earth salt is a rare earth tris (organophosphate), the organophosphate may be chosen from phosphoric acid diesters of general formula (R'0) (R "O) PO (OH), in which R 'and R ", which may be identical or different, represent an alkyl, aryl or alkylaryl radical. By way of example, mention may be made of neodymium tris [dibutyl phosphate], neodymium tris [dipentyl phosphate], neodymium tris [dioctyl phosphate], neodymium tris [bis (2-ethylhexyl) phosphate], neodymium tris [bis (1-methylheptyl) phosphate], neodymium tris [bis (p-nonylphenyl) phosphate], neodymium tris [butyl (2-ethylhexyl) phosphate], tris [(1-methylheptyl) 2-ethylhexyl) phosphate], neodymium tris [(2-ethylhexyl) (p-nonylphenyl) phosphate], neodymium tris [bis (2-ethylhexyl) phosphate], tris [bis (oleyllyl) phosphate] neodymium or tris [bis (linolyl) phosphate] neodymium.

 Among the rare earth organophosphates, the salt is more preferably tris [bis (2-ethylhexyl) phosphate] rare earth.

 The rare earth organic salt is preferably selected from neodymium tris [bis (2-ethylhexyl) phosphate] and neodymium tris (versatate).

 The rare earth salt is conventionally dissolved or suspended in a conventional manner in an inert hydrocarbon solvent chosen, for example, from low molecular weight aliphatic or alicyclic solvents such as, for example, cyclohexane, methylcyclohexane and n-heptane. , pentane or a mixture of these solvents.

As alkylating agent that may be used in the catalytic system according to the invention, mention may be made of alkylaluminiums chosen from trialkylaluminiums, or hydrides of dialkylaluminium, the alkyl group having from 1 to 10 carbon atoms. As tri (alkylaluminium), there may be mentioned triethylaluminium, tri-isopropylaluminium, triisobutylaluminium, tributylaluminium or trioctylaluminium.

 As alkylating agent that may be used in the catalytic system according to the invention, mention may also be made of aluminoxanes, compounds resulting from the partial hydrolysis of one or more trialkylaminiums, such as methylaluminoxane, triisobutylaluminoxane or else the methylaluminoxane.

 When the catalyst system comprises a halogen donor, an alkyl halide, an alkylaluminum halide or an alkylaluminum sesquihalide can be used. An alkylaluminium halide is preferably used, the alkyl group comprising from 1 to 8 carbon atoms. Of these, diethylaluminum chloride is preferred.

 According to a particular characteristic of the catalytic system, the rare earth metal or metals are present in the catalytic system in a concentration equal to or greater than 0.005 mol / l and, preferably, ranging from 0.010 to 0.1 mol / l and more particularly ranging from 0.02 mol / l to 0.08 mol / l.

 According to variants of the invention, the molar ratio (alkylating agent / rare earth salt (s)) in said catalytic system advantageously has a value of at least 1 and at most 50. According to certain variants of the process of the invention, this ratio is at most 30 or even at most 15. According to other variants of the process of the invention, this ratio is at least 4..

 According to variants of the invention, the molar ratio (halogen donor / rare earth salt) has a value ranging from 0.5 to 5, preferably from 2 to 3.6 and even more preferably from 2.5 to 3. , 2;

When the catalytic system comprises a preformed conjugated diene monomer used to "preform" said catalytic system, it may be chosen from the conjugated diene monomers mentioned above. 1,3-butadiene or isoprene are particularly preferred.

According to variants of the invention, the molar ratio (preforming monomer / rare earth salt (s)) has a value of at least 5, preferably at least 10, and at most 100, preferably, at most 90. According to some variants, this ratio has a value ranging from 15 to 70, or even 25 to 50. These variants and preferred aspects, although differentiated, are combinable with each other, be it the nature of the components of the catalytic system or of their proportion. As a preformed or non-formed catalyst system, it is possible to use in the context of the present invention those described in WO-A-02/38636, WO-A-03/097708, WO-A-2007045417 and PCT / EP2013 / 075437 in the name of the Applicants.

According to alternative embodiments of the catalytic polymerization process according to the invention, it is possible to introduce into the polymerization reactor, by a flow independent of the introduction of the catalytic system used for the polymerization reaction, a predetermined additional amount of at least one alkylaluminium compound of formula A1R ₃ or HA1R ₂ or R " _n AlR ' ₃ _ _n , in which R and R represent an alkyl group of 1 to 20 carbon atoms, saturated or unsaturated, preferably from 1 to 12 carbon atoms, carbon, R "represents an allyl group, n an integer inclusive of 1 to 3. Such variants are described in particular in the documents WO2006133757, EP 1845118, WO 10/069511, WO 10/069805.

 As the alkylaluminium compound, mention may be made of alkylaluminiums such as:

 trialkylaluminums such as, for example, trimethylaluminium, triethylaluminium, tri-n-propylaluminium, triisopropylaluminium, tri-n-butylaluminium, tri-t-butylaluminium, triisobutylaluminium, tri-n-pentylaluminium, tri-n-aluminum, n-hexylaluminum, tricyclohexylaluminum, preferably triisobutylaluminum or

 dialkylaluminum hydrides such as, for example, diethylaluminum hydride, diisopropylaluminum hydride, di-n-propylaluminum hydride, diisobutylaluminum hydride, di-n-octylaluminum hydride, hydride. di-n-butylaluminum, preferably diisobutylaluminum hydride.

 Advantageously, the molar ratio (alkylaluminium compound added in shifted / trialkylaluminium in the catalytic system) varies from 1/20 to 50/1, preferably varies from 1/15 to 30/1 and even more preferably from 1/10 to 20/1. .

It will be noted that the addition of the alkylaluminium compound before polymerization makes it possible to overcome the fluctuations in time of the impurities due to the solvents and monomers injected at the line inlet and not to penalize, because of these fluctuations, the activity of the catalytic system. This variant embodiment of the invention thus makes it possible to minimize the dispersion of the characteristics of the elastomer obtained. This variant is combinable with all the variants and implementations of the invention, preferred or not, described above or hereinafter.

 According to one implementation of the polymerization process of the invention, all the components of the initial reaction medium, that is to say the monomers to be polymerized, the optional solvent, the catalyst system and, where appropriate, the aluminum alkyl additional, can be introduced individually directly into the polymerization reactor.

According to other implementations of the process of the invention, at least two components of the initial reaction medium are not introduced individually directly into the polymerization reactor. The mixture of said components may be provided by various means known to those skilled in the art with static, dynamic or ultrasonic mixers. The mixture can be temperature-conditioned before entering the polymerization reactor.

 A second step of the process according to the invention relates to the polymerization of the diene monomers until reaching (1) a high degree of conversion of at least 60%, in limit of the first third of the reaction volume of the polymerization reactor with (2) a standard deviation of the residence time distribution function in the polymerization reactor greater than the average residence time divided by 2Λ / 3.

 According to the process of the invention, the degree of conversion of the monomers to polymer is at least 60%, in limit of the first third of the reaction volume of the polymerization reactor. The volume of the polymerization reactor is understood to mean the volume existing in the reactor between the point of entry of the reactants and the outlet of the reactor, excluding the discharge device.

This 60% conversion limit, associated with the specific characteristic relating to the residence time distribution function of the invention, is essential to overcome the formation of foam and to eliminate the phenomenon of expansion of the reaction medium. In fact, below 60% and without satisfying the condition relating to the residence time distribution function of the invention, the formation of bubbles is observed which rapidly leads to an uncontrollable expansion of the reaction medium. To achieve this necessary conversion rate of at least 60%, the skilled person has many levers or technical means that can vary in multiple combinations. Among these various technical levers include the reaction temperature, the monomer concentration in the reaction medium, the catalyst concentration in the reaction medium, the average residence time. .. The means to be used to reach at least 60%> of conversion to the limit of the first third of the reaction volume of the polymerization reactor are within the reach of those skilled in the art. The simple instruction to reach a minimum conversion limit, in this case at least 60% in limit of the first third of the reaction volume of the polymerization reactor, constitutes for him an identification of the combinations of means to be implemented to carry out this instruction. .

The conversion rate can be determined in various ways known to those skilled in the art. For example, the conversion rate can be determined from a measurement made on a sample taken at the limit of the first third of the reaction volume of the polymerization reactor, for example by gas chromatography (GC). The concentration of residual monomer (s) (unconverted) in the sample is measured. By difference between the concentration of the monomer (s) introduced into the polymerization reactor () and the concentration of residual monomer (s) measured in the sample taken (C _r ), the rate is determined. mass conversion as:

 with:

 X% mass: mass conversion rate;

 Ci: concentration of the monomer or monomers introduced into the polymerization reactor;

 concentration of the residual monomer (s) measured in the sample taken;

Preferably, this conversion rate is at least 80% and more preferably still 85% to 100%, for increasing productivity.

The process of the invention is also characterized by the flow conditions in the reactor during the polymerization reaction. The characterization of these flows by a residence time distribution function is such that the standard deviation of the residence time distribution function is greater than the average residence time divided by 2Λ / 3. More particularly, the standard deviation of the residence time distribution function is greater than the average residence time divided by 2. The residence time distribution function in the polymerization reactor can be determined in a manner known per se by a man of career. For example, it can be determined by modeling the experimental points obtained by measuring, by Gas Chromatography, the evolutions of the concentration of a tracer at the outlet of the reactor, following a very rapid injection, of this tracer, according to a mode of introduction. by impulse of a chemically inert product according to the principle described in the book Jacques Villermaux, Engineering of the chemical reaction: design and operation of the reactors. Editors. 1993, TEC & DOC - LAVOISIER, Page 170 to 172.

 The combination of these two characteristics of conversion rate and flow is one of the essential elements of the invention. Thus, according to the invention, a dienic polymer having a higher productivity and a remarkable flexibility due to the absence of expansion is available in a very concentrated and continuous medium.

 The thermal of the polymerization reaction is mainly regulated by the at least partial vaporization of the constituents of the non-polymeric phase of the reaction medium. The regulation of the thermal of the polymerization reaction by the vaporization of a part of the constituents of the non-polymeric phase of the reaction medium implies a free space (permanent or temporary) above said medium capable of accommodating the gas phase as has been defined previously. To control the temperature of the reactor and thus control the evacuation of the heat generated by the polymerization reaction, several configurations are possible.

 Thus, according to one variant, an internal condenser may be installed in the gas phase of the reactor.

According to another variant, an external condensation loop is used. According to this variant, part of the gas phase generated by the vaporization of the reaction medium during the polymerization, is driven by an outlet of the reactor to a condenser. The condensate may then advantageously be reinjected in all or part of the reactor, partly replacing the solvent and / or the monomers in the mixture of at least one monomer and solvent, or stored for later use. In the latter case, it is then necessary to readjust the flow into or out of the polymerization reactor so as to maintain constant reaction volume or residence time in the reactor. A device may be installed to remove the non-condensables either from the reactor or from the condensation loop depending on the variants used to control the thermal of the reaction. According to another variant, the thermal of the polymerization reaction can also be partially controlled by the cooling provided by the initial components injected into the polymerization reactor when the temperature of said components is at a lower temperature than the reaction medium. The initial components injected into the polymerization reactor can thus be regulated at the desired temperature between -5 ° C. and room temperature.

 According to other variants, the thermal of the polymerization reaction can also be partially controlled by the cooling via the double-envelopes or the stirring shafts of the reactors.

These different variants are combinable with each other, while knowing that the process is continuous, the combined variants take place simultaneously. At least the variant of the external condensation loop will be preferred since the exchange surface is not limited by the space available inside the reactor.

 The polymerization is carried out in the reactor under conditions of thermodynamic equilibrium between the polymerization medium and the gas phase. Thus, according to a particular implementation of the method of the invention, a regulation of the pressure of the gas phase in the reactor, more reactive than a temperature regulation can advantageously be implemented and allow to maintain the reaction medium to a pressure and therefore, due to the thermodynamic equilibrium, at a chosen temperature.

According to an implementation of the method of the invention, the polymerization reaction can also be conducted under vacuum, in which case a connection to a vacuum circuit can preferably be provided on the external condensation loop.

 The very low absolute pressure values allow polymerization at very low temperature, favorable operating conditions especially for the synthesis of certain diene elastomers.

 Typically, the polymerization proceeds at a temperature in the range of -30 ° C to 100 ° C. The flexibility of the process advantageously makes it possible to work temperatures between 20 ° C and 60 ° C, which do not require large energetic contributions, without penalizing the productivity of the process.

During the step of polymerization of the monomer or monomers, the reaction medium, which can reach a high viscosity, is kept under stirring by the movement around a rotary axis, preferably horizontal, of the stirring motive (s) of the reaction reactor. polymerization. Another step of the invention consists in continuously discharging a part of the reaction medium in the form of an elastomer paste comprising the synthesized pseudo-living elastomer. This continuous discharge is carried out by a discharge device totally or partially integrated into the polymerization reactor, such as a gear or screw extraction device, arranged at the bottom or on the side of the reactor. To control the output flow of the reactor, the additional devices can be installed at the outlet of the reactor. Thus, according to a particular variant of the invention, the elastomer paste is discharged by the combined action of at least one drain screw and a gear pump, which are both the discharge system, by gavage gears with the elastomer paste discharged by the screw device. It is thus advantageously possible to maintain a flow rate leaving the reactor that is equivalent to a flow rate entering the reactor in order to ensure continuous operation with a constant residence time.

When the discharge device comprises a screw, it can be single or double.

According to another step of the process of the invention the solution of pseudo-living elastomer discharged in step d), is conveyed continuously (step e) to a mixer having a gas phase, at least one movable stirrer and a discharge device, to be functionalized (step g) by a functionalization agent continuously introduced into said mixer (step f)).

 This mixer is advantageously self-cleaning. The term "self-cleaning" according to the invention, the fact that its stirring system sweeps at least 90% of the volume of the kneader, preferably 95% of the volume. Among the kneaders that can be envisaged, mention may be made of reactors of continuous kneading technology equipped with a device for discharging at least one screw, and in particular continuous mixers agitated with twin-screw discharge. Such kneaders are marketed, for example, by the company LIST AG under the name dual-arm kneader or "Twin Shaft Kneader Reactor" or by the company Buss-SMS-Canzler under the name of double-arm reactors or in English "large volume processors, twin shaft horizontal"

 According to the invention, in step (f), a functionalization agent capable of reacting with a pseudo-living elastomer obtained at the end of the coordination catalysis polymerization is introduced continuously into the kneader.

The functionalizing agent corresponds to the formula A-Ri-B with A denoting a group capable of reacting on the reactive end of the pseudo-living elastomer, Ri denoting an atom or a group of atoms forming a bond between A and B and B denoting a function capable of reacting with a reinforcing filler;

 The R 1 group is preferably a linear, branched or cyclic divalent hydrocarbon radical, and may contain one or more aromatic radicals, and / or one or more heteroatoms. Said radical R 1 can optionally be substituted, provided that the substituents are inert with respect to the reactive ends of the pseudo-living elastomer. According to preferred variants, the group R 1 denotes a divalent aliphatic hydrocarbon radical C1-C18, saturated or unsaturated, cyclic or otherwise, which may contain one or more aromatic radicals.

According to variants of the invention, a group capable of reacting on the reactive end of the pseudo-living elastomer is understood to mean a group chosen from, in particular, epoxides, glycidyloxy, carbonyls, aldehydes, ketones and esters. , carbonates, anhydrides, isocyanates, imines, alkoxysilanes, nitriles, aziridines, acyl chlorides, azines, cyclic halosilanes, oximes, ureas, methacrylates, hydrazones, lactones, thiolactones, thiocarboxylic acid esters, nitroso, carbamates.

 According to variants of the invention, the term functional group capable of interacting with a reinforcing filler is understood to mean a functional group comprising one or more functions chosen from a protected or non-protected primary amine, a protected secondary or a non-tertiary protected amine, an imide or an imide. , amide, nitrile, azo, carbamate, methacrylate, methacrylamide, hydroxyl, carbonyl, carboxyl, epoxy, glycidyloxy, thiol, sulfide, disulfide, thiocarbonyl, thioester, sulfonyl, silane, silanol, alkoxysilane, di-alkoxysilane, tri-alkoxysilane, stannyl, tin halide, tin halide alkyl, tin halide aryl, polyether , a nitrogenous heterocycle, an oxygenated heterocycle, a sulfur heterocycle and an aromatic group substituted with the aforementioned groups.

The various aspects, preferential or not, which precede and which concern in particular the nature of the group A, the group Ri and the function B, are combinable with each other. Thus, depending on the difficulties of synthesis and commercial availability, but especially as a function of the type of reinforcing filler envisaged in association with the modified elastomer, the skilled person will know which combinations, especially combinations of groups A and B cited above, are particularly advantageous. For example, it is possible, according to certain variants, to favor the groups glycydiloxy, epoxides, aldehydes, ketones, esters, alkoxysilanes, isocyanates, aziridines, acyl chlorides as a group capable of reacting on the reactive end of the pseudo-elastomer. living.

For example, it is also possible, according to certain variants, to favor the function, imine, the primary protected or unprotected amino function, secondary, protected or non-protected, or tertiary, the mono, di or trialkoxysilane function, optionally substituted with a group comprising a amino function, as a function likely to interact with a reinforcing filler

In certain embodiments, it is still possible to favor an alkyl radical in the form of -Qg, as a group forming a bond between A and B.

By way of illustration of these variants, mention may be made of functionalization agents such as (3-glycidyloxypropyl) methyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, N- (3-Triethoxysilylpropyl) -4,5-dihydroimidazole, 2- ( 3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3- (meth) acryloyloxypropyltrimethoxysilane, tris (3-triethoxysilylpropyl) isocyanurate, isocyanatopropyltriethoxysilane, (dioctyltin bis (2-ethylhexyl) maleate, 3-aminopropyltriethoxysilane, 3-mercaptopropyltriethoxysilane, 3-dimethylaminopropyl (triethoxy) silane, dibutyl bisbenzyl maleate tin, 4,4'-bis (diethylamino) benzophenone, Ν ', Ν-dimethylimidazolidinone, dichloronapthoquinone, diethylaminobenzaldehyde, 4,4'-diphenylmethanediisocyanate polymethylenepolyphenylpolyisocyanate, 1,3-hexamethylenediisocyanate, 2,6-toluenediisocyanate, 1-butylaziridine, trimethylolpropane tris [3- (1-aziridinyl) propionate], butyrylaziridine, 2- (4-morpholinodithio) benzothiazole, N-oxydiethylene-2-benzothiazole sulfamamide, diethyldithiocarbamic acid 2-benzothiazoyl ester, N- (cyclohexylthio) phathalimide, dimethylcarbamic chloride, 4-morpholinecarbonylchloride. Among these functionalizing agents, (3-glycidyloxypropyl) methyldiethoxysilane is particularly advantageous. The functionalization step is carried out by reaction of at least one functionalization agent described above with the pseudo-living elastomer solution at a temperature in the range of -30 ° C to 100 ° C. According to some variants Advantageously, the functionalization can be carried out at temperatures between 40 ° C and 70 ° C.

 The reaction time is at least 10 minutes.

 The amount of functionalizing agent can vary over a wide range. According to variants of the invention, the molar ratio (functionalizing agent / total aluminum) is at least 1/1 and at most 10/1, preferably at most 5/1, or even at most 2/1. Total aluminum is the total amount of aluminum present in the reaction medium, taking into account the aluminum included in the alkylating agent and, if appropriate, the aluminum included in the additional alkylaluminium compound added in offset relative to to the catalytic system.

According to one embodiment of the invention, the kneader can concomitantly with the functionalization, be used to concentrate the reaction medium by removing, if necessary, a part of the solvent, and / or unreacted monomers. A condensation loop is then used. This loop works in the same way as that of the polymerization reactor described above. The condensate stream may advantageously be reintroduced in all or part upstream of the first reactor, partly replacing the solvent and / or the monomers in the mixture of at least one monomer and solvent or stored for later use.

According to another embodiment, the kneader may also, concomitantly with the functionalization, be used to devolatilize the reaction medium by optionally removing the solvent, and / or unreacted monomers. A condensation loop is then used. This loop works in the same way as that of the polymerization reactor described above. The condensate stream may advantageously be reintroduced wholly or partly upstream of the polymerization reactor, partly replacing the solvent and / or the monomers in the mixture of at least one monomer and solvent or stored for later use. .

 According to an advantageous implementation of the invention, the kneader is dedicated to functionalization, without it being implemented concomitant concentration or devolatilization reaction.

It is understood that, insofar as it is a continuous process, these different stages, when combined, are implemented simultaneously. The elastomer paste resulting from this functionalization step (step (g)) is continuously discharged of this mixer (step h). This continuous discharge is effected by a device which is provided with the mixer. Additional devices for the transport of the products can be installed at the outlet of the reactor discharge device to control the output flow rate. Thus, according to a particular variant of the invention, the latter is discharged by the combined action of at least one drain screw and a gear pump which both constitute the discharge system, by feeding the gears with the elastomer paste discharged by the screw device.

At this stage and according to a variant of the invention, the method for synthesizing a functionalized diene elastomer can be continued in a manner known per se. Thus, according to one embodiment, it is possible to inject a stopper and an antioxidant at this stage.

Another step of the process of the invention consists in cutting the functionalized elastomer paste discharged. The elastomer paste is conveyed to a device for cutting it. This type of device is preferably a granulator which makes it possible to transform the dough into particles of variable shapes and average volumes of between 0.07 cm ³ and 12 cm ³ .

 The granulation step can be carried out under various conditions known to those skilled in the art and which are suitable for the process according to the invention. Thus, for example, the granulation can be carried out under water to feed a step of removing the solvent from the particles of the elastomer paste by steam stripping, or in a gaseous phase allowing feeding a step of removing the solvent from the particles of the elastomer paste by drying different from the stripping with water. In a preferred aspect, the granulation will be carried out under water. . For example, this type of underwater granulator is marketed under various names such as underwater pelletizer, or in English "Underwater Pelletizers", marketed by Gala Industries, the underwater granulator, or in English "Underwater Pelletizing By Kreyenborg Industries.

 The process is then continued in a manner known per se by separating and recovering the functionalized diene elastomer prepared. The unreacted monomers and / or the solvent contained in the elastomer paste, in particulate form, can be removed according to methods known to those skilled in the art.

The functionalized elastomer recovered at the end of these different steps can then be packaged in a manner known per se, in the form of balls for example. The method of the invention makes it possible to synthesize, by coordination catalysis, functionalized elastomers characterized by a molar ratio of cis of at least 95% with respect to the elastomer, and by an average percentage of functionalized chains of at least 70%, up to 100%. This synthesis also offers the energy and environmental benefits of polymerization in highly concentrated media while ensuring increased productivity with a conversion rate of over 60%.

The invention also relates to any installation for implementing the continuous synthesis process of a functionalized diene elastomer and suitable for application on an industrial scale.

 By way of nonlimiting illustration, an installation for the continuous synthesis of a functionalized diene elastomer in accordance with one embodiment of the synthesis method of the invention is more particularly described with reference to FIG. 1 constituting a schematic representation of an installation for implementing the method.

 Figure 1 is a diagram of an installation according to one embodiment of the invention for the continuous synthesis of a diene elastomer by coordination catalysis integrating a polymerization reactor, a self-cleaning mixer and a granulator.

The installation illustrated in FIG. 1 essentially comprises a polymerization reactor 1 which is provided with a gas phase and equipped with at least one stirring mobile, preferably with a double Z-arm, and with a discharge device at least one screw. In addition, the reactor 1 is characterized by a specific flow so that the residence time distribution function is such that the standard deviation of this function is greater than the average residence time divided by 2Λ / 3, preferably greater than average residence time divided by 2.

The polymerization reactor 1 is at least connected

at several sources of continuous supply of which at least one feed source 2 in a catalytic system, a feed source 3 in at least one monomer, optionally mixed with the inert hydrocarbon solvent, and - At an outlet adapted to evacuate said reactor 1, continuously, the elastomer paste in a flow exiting by a discharge device.

 According to the variant of the installation illustrated in FIG. 1, the polymerization reactor 1 is connected to a supply source 3 in a mixture of at least one monomer and of solvent. A mixer 4, situated upstream of the polymerization reactor 1, makes it possible to carry out this mixing. This mixer 4 is fed by a source of at least one monomer 5 and a source of solvent 6, and is connected to the polymerization reactor 1.

According to alternative embodiments of the catalytic polymerization process according to the invention, it is possible to introduce into the polymerization reactor, by a separate flow and independent of the introduction of the catalytic system used for the polymerization reaction, a predetermined additional quantity. at least one alkylaluminium compound. According to an alternative installation illustrated by dashed lines in FIG. 1, the polymerization reactor 1 is also connected to an additional alkylating agent supply source 7. The alkylating agent may, alternatively, be added to the mixture of monomer and solvent, before entering the reactor 1, the additional alkylating agent supply source 7 thus being connected to the monomer and solvent supply source 3, as shown in dashed lines in FIG. Alternatively, according to another alternative also illustrated in FIG. 1 by dotted lines, the alkylating agent can be injected directly into the mixer 4 to be mixed with the monomer and with the solvent, the additional alkylating agent supply source being then connected to the mixer 4.

 According to a variant of the installation illustrated in FIG. 1, the catalytic system feed source 2 can be connected to a non-illustrated installation for the continuous preparation of the catalytic system as described in EP 1 968 734 A1.

The polymerization reactor 1 is provided with a discharge device with at least one screw which makes it possible to continuously discharge the elastomer paste in an outgoing flow 9. This discharge device consists of at least one emptying screw, integrated in the reactor 1, and a gear pump 10 downstream of the reactor 1.

 According to certain implementations of the polymerization process, the thermal of the polymerization reaction is regulated by the at least partial vaporization of the non-polymeric constituents of the reaction medium. In FIG. 1 illustrating a variant of this process, the polymerization reactor 1 is equipped with a condensation loop which enables

the condensation of the gases coming from the reactor 1 via a condenser 8 and - The return in all or part of the condensate in the reactor 1.

According to an optional embodiment not illustrated, the condensation loop may advantageously be connected to a device for the elimination of incondensable products in a manner known per se.

 The plant also comprises a kneader 11 downstream of the polymerization reactor 1 and connected thereto via the gear pump 10. The kneader 11 has a stirring device which sweeps at least 90% of the volume of the kneader, preferably 95% of its volume, thus ensuring a self-cleaning.

The kneader 11 is at least provided

 an inlet connected to a supply source of pseudo-living elastomer paste discharged from the polymerization reactor 1 by the gear pump 10,

 an input connected to a supply source 12 as functionalization agent

 an outlet suitable for discharging from said mixer 11, continuously, the functionalized elastomer paste into a flow coming out towards the pump 16.

 The kneader 11 is provided with a discharge device with at least one screw which makes it possible to continuously discharge the functionalized elastomer paste in an outgoing flow 13. This discharge device consists of at least one emptying screw, integrated to the mixer 11 and a gear pump 16 located downstream of the mixer 11.

 The flow of functionalized elastomer paste 13 is conveyed to the granulator 17, preferably under water, to be cut through the gear pump 16 which is connected to the granulator.

 According to the implementation of the polymerization process illustrated in FIG. 1, the mixer 11 is exclusively dedicated to functionalization.

 According to alternative arrangements of other implementations of the process, not illustrated in FIG. 1, the mixer 11 may be equipped with a condensation loop which allows the condensation of the gases coming from the reactor 11 via a condenser and the return all or part of the condensate in the polymerization reactor 1.

According to one embodiment of these non-illustrated variants, the condensation loop may advantageously be connected to a device for the elimination of incondensable products in a manner known per se. According to the embodiment of the invention illustrated in FIG. 1, a stopper and an antioxidant are then injected into the flow of the functionalized elastomer paste 13 discharged from the kneader 1 1, respectively through feed sources 14 and 15. upstream of the gear pump 16.

The installation illustrated in Figure 1 further comprises a cutting device 17, for example a granulator preferably under water. The cutting device 17 is provided with an inlet connected to the gear pump 16 through which the discharge device feeds the device 17 of elastomer paste to be cut. The device 17 is also provided with an outlet adapted to evacuate from said device 17, continuously, the elastomer paste particles functionalized in a stream 18, to a device for the elimination of the solvent and isoprene. .

A - METHODS OF MEASUREMENT

I - Determination of the microstructure of the polyisoprenes obtained

The so-called "near infrared" (NIR) assay technique was used. This is an indirect method using "control" elastomers whose microstructure has been measured by the ¹³ C NMR technique. The quantitative relationship (Beer-Lambert law) existing between the distribution of monomers in an elastomer and the shape of the NIR spectrum thereof. This technique is implemented in two steps:

1) Calibration:

The respective spectra of the "control" elastomers are acquired. - A mathematical model associating a microstructure with a given spectrum is established using the Partial Least Squares (PLS) regression method based on a factorial analysis of the spectral data. The following two papers deal extensively with the theory and implementation of this "multi-varied" data analysis method:

 (1) P. GELADI and B. R. KOWALSKI

 "Partial Least Squares Regression: a tutorial,"

 Analytica Chimica Acta, vol. 185, 1-17 (1986).

 (2) M. TENENHAUS

 «PLS regression - theory and practice»

 Paris, Technip Publishing (1998).

2) Measure:

The spectrum of the sample is recorded.

 - The calculation of the microstructure is carried out.

II - Determination of the amount of GMDE grafted to the polyisoprenes obtained, a) Principle This determination is carried out by NMR analysis on coagulated samples.

 The spectra are acquired on a BRUKER 500 MHz Avance spectrometer equipped with a BBIz-grad 5 mm wideband probe.

 The quantitative 1H NMR experiment uses a 30 ° single-pulse sequence and a 5-second repetition time between each acquisition (1024 acquisitions). b) Sample preparation:

Samples, about 25mg, are solubilized in carbon disulfide (CS ₂ ), about 1mL.

 100% of deuterated cyclohexane (C6D12) are added for the lock signal. c) Characterization:

 The 1 H NMR spectrum makes it possible to quantify the ethylenic units of the IR by integration of the proton characteristic massifs according to:

 PI 1-4: 1H ethylenic δppm 1H massive between 5.40ppm and 4.75ppm

PI3-4: ^2H? Ppm 1H ethylenic solid between 4.75ppm and 4.30ppm

The chemical shifts are calibrated with respect to the protonated impurity of CS ₂ δppm 1H at 7.18ppm referenced on the TMS (δppm 1H at Oppm).

The 1 H NMR spectrum makes it possible to quantify the grafted GMDE units by integrations of the proton characteristic massifs according to:

CH ₂ -0-Si-: öppm 1H solid at 3.6ppm

-CH ₂ -O- + -CH-O-: öppm 1H solid at 3.25ppm

-CH ₂ -O-: öppm 1H solid at 3.00ppm

CH ₃ -S1-: solid 1Hpp at -0.02ppm

CH ₂ -Si: Oppm 1H massive at 0.46ppm

The chemical shifts are calibrated with respect to the protonated impurity of CS ₂ δppm 1H at 7.18ppm referenced on the TMS (δppm 1H at Oppm).

The 2D NMR correlation spectrum 1H / ¹³ C ^I J HSQC edited makes it possible to verify the nature of the grafted pattern by virtue of the chemical shifts of the carbon and proton atoms. III - Determination of the molecular weight distribution of polyisoprenes obtained by the steric exclusion chromatography (SEC) technique. a) Principle of the measure:

Size Exclusion Chromatography (SEC)

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

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

There is no particular treatment of the polymer sample before analysis. This is simply solubilized in tetrahydrofuran at a concentration of about

1 g / i. c) SEC analysis:

Case cl) The equipment used is a "WATERS alliance" chromatographic chain. The elution solvent is tetrahydrofuran, the flow rate is 1 ml / min, the temperature of the system is 35 ° C and the analysis time is 30 min. A set of two WATERS columns with the trade name "STYRAGEL HT6E" is used.

The injected volume of the solution of the polymer sample is 100 μl. The detector is a differential refractometer "WATERS 2140" and the chromatographic data exploitation software is the "WATERS MILLENNIUM" system. Case c2) The apparatus used is a "WATERS alliance" chromatograph. The elution solvent is tetrahydrofuran, the flow rate 0.7 ml / min, the system temperature 35 ° C and the analysis time 90 min. A set of four WATERS columns in series, trade names "STYRAGEL HMW7", "STYRAGEL HMW6E" and two "STYRAGEL HT6E" are used.

The injected volume of the solution of the polymer sample is 100 μl. The detector is a "WATERS model RI32X" differential refractometer and the chromatographic data exploitation software is the "WATERS MILLENIUM" system.

B - TESTS Synthesis processes of a polyisoprene functionalized by coordination catalysis in a highly concentrated medium according to a variant of the invention

Some definitions:

 Nd = neodymium

 Bd = butadiene

 Isop = isoprene

 MCH = methylcyclohexane

 HDiBA = diisobutylaluminum hydride

 TOA = trioctylaluminum

 CDEA = diethylaluminum chloride

 TiBA = triisobutylaluminum

 GMDE = (3-glycidyloxypropyl) methyldiethoxysilane I - Synthesis of catalytic systems

1 - Nd / Bd / HDiBA / CDEA

The Nd / Bd / HDiBA / CDEA catalytic system diluted in MCH is synthesized according to the procedure described in WO-A-02/38636 in the name of the Applicants: In order to obtain this catalyst, the powdered neodymium phosphate salt is introduced into a reactor previously cleaned of its impurities. This salt is then sparged with nitrogen for 10 min in order to render the reaction medium inert. The following successive steps are then performed:

- First solvation step:

 A solvent consisting of previously distilled MCH, purified on alumina and bubbled with nitrogen is introduced into the reactor. In order to form a gel, the duration and the temperature of contacting this solvent with the neodymium salt are 30 minutes at 30 ° C. with stirring.

 Second stage of addition of the monomer:

 The butadiene previously purified on alumina and sparged with nitrogen is then introduced into the reactor at 30 ° C. This monomer will be used to preform the catalyst during the aging step.

Third stage of alkylation:

 The HDiBA in solution in the MCH is then introduced into the reactor as an agent for alkylating the neodymium salt, at a concentration of approximately 1 mol / l. The duration of the alkylation is 15 min. The temperature of the alkylation reaction is 30 ° C.

- Fourth step of halogenation:

The CDEA in solution in the MCH is then introduced into the reactor as a halogen donor at a concentration of about 0.5 mol / L. The temperature of the reaction medium is brought to 60 ° C.

 - Fifth stage of aging:

 The mixture thus obtained is aged maintaining the temperature of 60 ° C for a period of 50 minutes.

 The catalytic solution obtained is finally stored under a nitrogen atmosphere at a temperature of between -15 ° C. and -5 ° C.

The catalytic system is characterized by its catalytic formula which is given in the form of Nd / Monomer / Alkylating Agent / Halogenating Agent in molar ratios indexed on the neodymium salt. In the examples, the neodymium concentration is 0.02 mol / L. 2 - Nd / Isop / TOA / CDEA

 The Nd / Isop / TOA / CDEA catalyst system is diluted in n-pentane.

In order to obtain this catalyst, the powdered neodymium phosphate salt is introduced into a reactor previously cleaned of its impurities. This salt is then sparged with nitrogen for 10 min in order to render the reaction medium inert. The following successive steps are then performed:

- First solvation step:

A solvent consisting of n-pentane previously purified on alumina and bubbled with nitrogen is introduced into the reactor. In order to form a gel, the duration and the temperature of contacting this solvent with the neodymium salt are 30 minutes at 30 ° C. with stirring.

Second stage of addition of the monomer:

 The isoprene previously purified on alumina and bubbled with nitrogen is then introduced into the reactor at 30 ° C. This monomer will be used to preform the catalyst during the aging step.

 Third stage of alkylation:

 The TOA in solution in n-pentane is then introduced into the reactor as agent for alkylation of the neodymium salt, at a concentration of approximately 1 mol / l. The duration of the alkylation is 15 min. The temperature of the alkylation reaction is 30 ° C.

- Fourth step of halogenation:

 CDEA dissolved in n-pentane is then introduced into the reactor as a halogen donor at a concentration of about 0.5 mol / L. The temperature of the reaction medium is brought to 60 ° C.

- Fifth stage of aging:

 The mixture thus obtained is aged maintaining the temperature of 60 ° C for a period of 50 minutes.

 The catalytic solution obtained is finally stored under a nitrogen atmosphere at a temperature of between -15 ° C. and -5 ° C.

The catalytic systems are characterized by their catalytic formula which is given in the form of Nd / Monomer / Alkylating Agent / Halogenating Agent in molar ratios indexed on the neodymium salt. In the examples, their neodymium concentration is 0.02 mol / L. II - Procedure followed for continuous polymerizations

Example 1

 The continuous polymerization is carried out on a line comprising a reactor with a double Z-arm gas phase of 150 liters total, equipped with a discharge device with a drain screw and a gear pump and a self-cleaning mixer, also equipped with a discharge device with a drain screw and a gear pump. This continuous line corresponds to the installation shown in FIG.

 Isoprene and pentane are mixed in a dynamic mixer 4 provided for this purpose upstream of the polymerization reactor 1. The mixture obtained is injected in the form of an incoming stream 3 directly into the reactor 1.

 Isoprene is injected at a flow rate of 7.8 kg / h according to a flow 5 in the mixer 4.

 Pentane is injected with a flow rate of 12.54 kg / h according to a flow 6 in the mixer 4, ie about 37% by weight of monomer in the reaction medium.

A catalytic coordination system is also injected directly into the reactor 1 in a stream 2. It has been prepared by following the method of preparation described in paragraph I above, part 2.

 The catalytic system has the following molar ratios with respect to neodymium:

 Nd / isoprene / TOA / CDEA = 1/30/8 / 2.8

 The amount of neodymium is 150μι οΐ68 per 100g of isoprene to be polymerized. The molar concentration of neodymium in the catalyst is 0.02 mol / l.

TiBa is also injected directly into the reactor 1 in a separate and independent stream 7, as an additional alkylaluminium compound. The amount of TiBa injected is 680 μmol / 100 g of isoprene. The molar concentration of the TiBa solution is 0.1 mol / L.

The pressure of the gas phase is regulated to 0.5 barg, the vapors are condensed in an external condenser 8 and returned to the polymerization reactor 1 with a double Z-arm. The temperature of the jacket is maintained at 60 ° C.

The mean residence time t ₀ of the reaction is 80 minutes. The discharge screw makes it possible to transfer the product of the reactor 1 to a gear pump 10.

 No expansion phenomenon is observed.

 The conversion measured on a sample taken at the limit of the first third of the reactor volume is 91%. The conversion measure was derived from a GPC measurement of isoprene in the sample taken. Residual isoprene in the sample taken was assayed at 3.4% by mass.

The flows are characterized by the residence time distribution given in FIG.

 The experimental points allowing to establish this distribution of residence time were obtained by measuring by Gas Chromatography the evolutions of concentration of a tracer following a very fast injection according to a mode of impulse introduction of a chemically inert product. according to the principle described in the book Jacques Villermaux, Chemical reaction engineering: design and operation of reactors. Editors. 1993, TEC & DOC - LAVOISIER, Page 170 to 172. The experimental points are taken from samples taken in the stream 9 of Figure 1 at the outlet of the reactor 1, at the end of the discharge screw. The modeling of these experimental points by a gamma law made it possible to determine the variance of the residence time distribution function E.

 The gamma law for modeling the residence time distribution function E is as follows:

 - t

T (k) t ₀ ^k With:

r (k): gamma function of k;

k: 1.22;

to: average residence time, 80 minutes;

t: residence time;

The variance of this residence time distribution function is equal to t ₀ ² We deduce the standard deviation of the residence time distribution function which is equal to

88.4, which is greater than the average residence time divided by 2Λ / 3,

 23.1. The discharge screw makes it possible to transfer the product of the reactor 1 to a gear pump 10.

The gear pump 10 transfers the pseudo-living elastomer paste to a self-cleaning mixer with gas phase 11. The flow rate transferred by the gear pump 10 is equal to the sum of the flow rates injected into the reactor 1.

 The self-cleaning kneader is a 39 liters total volume double-arm kneader-mixer with a dump twin-screw discharge device and a gear pump 16. Flow in this double-arm kneader-mixer can be likened to a piston flow.

 The temperature of the jacket is maintained at 68 ° C.

 The average residence time of the functionalization reaction with the pseudo-living polymer solution in the self-cleaning mixer 11 is 37 minutes.

The GMDE is injected with a flow rate of 0.456 l / h in the self-cleaning mixer at the same level as the arrival of the solution in the mixer. The GMDE solution is concentrated at 0. 47 mol / L.

 The flow stopper 14 and the antioxidant flux used are acetyl acetone, with a flow rate of 0.224 l / h at a concentration of 120 g / l, and N, 3-dimethylbutyl-N'-phenyl-para-phenylenediamine, according to 0.5 μcm (mw: parts by weight per 100 parts by weight of monomer-isoprene). This stopper and this antioxidant are injected upstream of the gear pump 16;

 The gear pump 16 transfers the elastomer paste to the underwater granulator 17. The flow rate transferred by the gear pump 16 is equal to the sum of the flow rates injected into the reactor 1, to which is added the flow rates of the functionalizing streams. stopper 14 and antioxidant 15.

The degree of functionalization obtained is 70%.

Example 2

The continuous polymerization is carried out on a line comprising a reactor with a double Z-arm gas phase of 150 liters total, equipped with a discharge device with a drain screw and a gear pump and a self-cleaning mixer, also provided with a discharge device with a drain screw and a gear pump. This continuous line corresponds to the installation shown in FIG. 1. Isoprene and pentane are mixed in a dynamic mixer 4 provided for this purpose upstream of the polymerization reactor 1. The mixture obtained is injected in the form of an incoming stream 3 directly into the reactor 1.

 Isoprene is injected with a flow rate of 7.52 kg / h according to a flow 5 in the mixer 4.

Pentane is injected at a flow rate of 12.01 kg / h according to a flow 6 in the mixer 4, ie about 37% by weight of monomer in the reaction medium.

A catalytic coordination system is also injected directly into the reactor 1 in a stream 2. The catalyst system is based on tris [bis- (2-ethylhexyl) phosphate] neodymium, isoprene as pre-forming monomer, TOA as an alkylating agent and CDEA as a halogen donor. It has been prepared following the method of preparation described in the previous paragraph, Part 2.

 The catalytic system has the following molar ratios with respect to neodymium:

 Nd / isoprene / TOA / CDEA = 1/30/8 / 2.8

The amount of neodymium is Πθμιηοΐεβ per 100g of isoprene to be polymerized. The molar concentration of neodymium in the catalyst is 0.02 mol / l.

TiBa is also injected directly into reactor 1 in a separate and independent stream 7 as an additional alkylaluminum compound. The amount of TiBa injected is 2200 μmol / 100 g of isoprene to be polymerized. The molar concentration of the TiBa solution is 0.294 mol / L.

The pressure of the gas phase is regulated at 0.16 barg, the vapors are condensed in an external condenser 8 and returned to the polymerization reactor 1 with a double Z-arm.

The temperature of the jacket is maintained at 21 ° C.

The mean residence time t ₀ of the reaction is 80 minutes.

The discharge screw makes it possible to transfer the product of the reactor 1 to a gear pump 10. No expansion phenomenon is observed.

The conversion measured on a sample taken at the limit of the first third of the reactor volume is 92%. The conversion measure was derived from a GPC measurement of isoprene in the sample taken. Residual isoprene, in the sample taken, was assayed at 2.9% by mass.

The flows are characterized by the residence time distribution given in FIG.

The experimental points allowing to establish this distribution of residence time were obtained by measuring by Gas Chromatography the evolutions of concentration of a tracer following a very fast injection according to a mode of impulse introduction of a chemically inert product. according to the principle described in the book Jacques Villermaux, Chemical reaction engineering: design and operation of reactors. Editors. 1993, TEC & DOC - LAVOISIER, Page 170 to 172. The experimental points are taken from samples taken in the stream 9 of Figure 1 at the outlet of the reactor 1, at the end of the discharge screw.

The modeling of these experimental points by a gamma law made it possible to determine the variance of the residence time distribution function E.

 The gamma law for modeling the residence time distribution function E is as follows:

 - t

T (k) t ₀ ^k With:

r (k): gamma function of k;

k: 1.22;

t ₀ : average residence time, ie 80 minutes;

t: residence time; The variance of this residence time distribution function is equal to k * t We deduce the standard deviation of the residence time distribution function which is equal to

88.4, which is greater than the average residence time divided by 2Λ / 3,

 23.1. The discharge screw makes it possible to transfer the product of the reactor 1 to a gear pump 10.

The gear pump 10 transfers the pseudo-living elastomer paste to a self-cleaning mixer with gas phase 11. The flow rate transferred by the gear pump 10 is equal to the sum of the flow rates injected into the reactor 1.

 The self-cleaning kneader is a 39 liters total volume double-arm kneader-mixer with a dump twin-screw discharge device and a gear pump 16. Flow in this double-arm kneader-mixer can be likened to a piston flow.

 The temperature of the jacket is maintained at 68 ° C.

 The average residence time of the functionalization reaction with the pseudo-living polymer solution in the self-cleaning mixer 11 is 37 minutes.

The GMDE is injected with a flow rate of 0824 1 / h into the self-cleaning mixer at the same level as the arrival of the solution in the mixer. The GMDE solution is concentrated at 0. 45 mol / L.

 The flow stopper 14 and the flow antioxidant used are acetyl acetone, with a flow rate of 0.387 l / h at a concentration of 120 g / l, and N, 3-dimethylbutyl-N'-phenyl-para-phenylenediamine, according to 0.5 μcm (mw: parts by weight per 100 parts by weight of monomer-isoprene). This stopper and this antioxidant are injected upstream of the gear pump 6.

 The gear pump 16 transfers the elastomer paste to the underwater granulator 17. The flow rate transferred by the gear pump 16 is equal to the sum of the flow rates injected into the reactor 1, to which is added the flow rates of the functionalizing streams. stopper 14 and antioxidant 15.

The degree of functionalization obtained is 100%.

Example 3

The continuous polymerization is carried out on a line comprising a reactor with a double Z-arm gas phase of 150 liters total, equipped with a discharge device with a drain screw and a gear pump and a self-cleaning mixer, also provided with a discharge device with a drain screw and a gear pump. This continuous line corresponds to the installation shown in FIG. 1. Isoprene and pentane are mixed in a dynamic mixer 4 provided for this purpose upstream of the polymerization reactor 1. The mixture obtained is injected in the form of an incoming stream 3 directly into the reactor 1.

 Isoprene is injected with a flow rate of 7.52 kg / h according to a flow 5 in the mixer 4.

Pentane is injected with a flow rate of 12.26 kg / h according to a flow 6 in the mixer 4, ie about 37% by weight of monomer in the reaction medium.

A catalytic coordination system is also injected directly into the reactor 1 in a stream 2. The catalytic system is based on tris [(2-ethylhexyl) phosphate] neodymium, butadiene as pre-forming monomer, HDiBa as alkylating agent and CDEA as a halogen donor. It has been prepared following the method of preparation described in the preceding paragraph, Part 1.

 The catalytic system has the following molar ratios with respect to neodymium:

 Nd / butadiene / HDiBa / CDEA = 1/30 / 1.8 / 2.6

The amount of neodymium is Πθμιηοΐεβ per 100g of isoprene to be polymerized. The molar concentration of neodymium in the catalyst is 0.02 mol / l.

No additional alkylaluminium compound is injected.

The pressure of the gas phase is regulated at 0.16 barg, the vapors are condensed in an external condenser 8 and returned to the polymerization reactor 1 with a double Z-arm.

The temperature of the jacket is maintained at 35 ° C.

The mean residence time t ₀ of the reaction is 80 minutes.

 The discharge screw makes it possible to transfer the product of the reactor 1 to a gear pump 10.

No expansion phenomenon is observed. The conversion measured on a sample taken at the limit of the first third of the reactor volume is 91%. The conversion measure was derived from a GPC measurement of isoprene in the sample taken. Residual isoprene in the sample taken was assayed at 3.4% by mass.

The flows are characterized by the residence time distribution given in FIG.

 The experimental points allowing to establish this distribution of residence time were obtained by measuring by Gas Chromatography the evolutions of concentration of a tracer following a very fast injection according to a mode of impulse introduction of a chemically inert product. according to the principle described in the book Jacques Villermaux, Chemical reaction engineering: design and operation of reactors. Editors. 1993, TEC & DOC - LAVOISIER, Page 170 to 172. The experimental points are taken from samples taken in the stream 9 of Figure 1 at the outlet of the reactor 1, at the end of the discharge screw.

The modeling of these experimental points by a gamma law made it possible to determine the variance of the residence time distribution function E.

 The gamma law for modeling the residence time distribution function E is as follows:

 - t

E =

Y (k) t _n ^k

With:

r (k): gamma function of k;

k: 1.22;

to: average residence time, 80 minutes;

t: residence time;

The variance of this residence time distribution function is equal to k * t ₀ ²

 We deduce the standard deviation of the residence time distribution function which is equal to 80

88.4, which is greater than the average residence time divided by 2Λ / 3, ie J ~ ⁼ 23.1. The discharge screw makes it possible to transfer the product of the reactor 1 to a gear pump 10.

 The gear pump 10 transfers the pseudo-living elastomer paste to a self-cleaning mixer with gas phase 11. The flow rate transferred by the gear pump 10 is equal to the sum of the flow rates injected into the reactor 1.

 The self-cleaning kneader is a 39 liters total volume double-arm kneader-mixer with a dump twin-screw discharge device and a gear pump 16. Flow in this double-arm kneader-mixer can be likened to a piston flow.

The temperature of the jacket is maintained at 68 ° C.

 The average residence time of the functionalization reaction with the pseudo-living polymer solution in the self-cleaning mixer 11 is 37 minutes.

The GMDE is injected with a flow rate of 0.172 l / h into the self-cleaning mixer at the same level as the arrival of the solution in the mixer. The GMDE solution is concentrated at 0. 45 mol / L.

 The flow stopper 14 and the antioxidant flux used are acetyl acetone, with a flow rate of 0.321 l / h at a concentration of 26 g / l, and N, 3-dimethylbutyl-N'-phenyl-para-phenylenediamine, according to 0.5 μcm (mw: parts by weight per 100 parts by weight of monomer-isoprene). This stopper and this antioxidant are injected upstream of the gear pump 16.

 The gear pump 16 transfers the elastomer paste to the underwater granulator 17. The flow rate transferred by the gear pump 16 is equal to the sum of the flow rates injected into the reactor 1, to which is added the flow rates of the functionalizing streams. , stopper 14 and antioxidant 15.

The degree of functionalization obtained is 75%.

Witness

A non-functional polyisoprene was synthesized according to the method described in Example 1 using a catalytic system having the following molar ratios with respect to neodymium: Nd / isoprene / TOA / CDEA = 1/30/8 / 2.8, at the except that no functionalising agent has been introduced into the mixer 11. The amount of neodymium is 100 μηιοΐεβ per 100g of isoprene to be polymerized. The molar concentration of neodymium in the catalyst is 0.02 mol / l.

TiBa is also injected directly into the reactor 1 in a separate and independent stream 7 as an additional alkylaluminium compound. The amount of TiBa injected is 900 μmol / 100 g of isoprene. The molar concentration of the TiBa solution is 0.1 mol / L.

For all previous polymerizations, the conversion measured on a sample taken from the stream 9 upstream of the gear pump 10 is 99% at 80 min of overall reaction time. The conversion measure was derived from a GPC measurement of isoprene in the sample taken.

Tables 1 and 2 show the polymerization tests carried out with the two types of catalytic system and the associated functional polyisoprenes.

Table 1:

 Witness

Catalytic formula Nd / lsop / TOA CDEA

Stoichiometry 1/30/8 / 2.8

Concentration Nd (μητΐϋΐτι) 100

TiBA transfer agent

 Tranferant concentration (μητΐϋΐτι) 900

Reactor gas phase pressure (Barg) 0.50

Mn / lp (g, mol ^"1 / -) 428500 / 2.25

Cits (%) 95.1

Table 2:

 Examples

 1 2 3

 Nd / Isop / TOA / CDEA Nd / Isop / TOA / CDEA Nd / Bd / HDiBA / CDEA Catalytic Formula

Stoichiometry 1/30/8 / 2.8 1/30/8 / 2.8 1/30 / 1.8 / 2.6

Concentration Nd (μιηοιη) 150 170 170

 TiBA transfer agent TiBA -

Tranfer concentration (μιηαη) 680 2200 0

 Pressure gas phase reactor (Barg) 0.50 0.16 0.16

GMDE / AI total 1.2 1.2 1.2

Mn / lp (g.mol ^"1 / -) 440000 / 2.28 436200 / 2.46 439000 / 2.36

CH2-Si / PI ¹ H NMR (meq / Kg) 1.6 2.3 1.7

 % average functionalized chains (%) 70 100 75

 Cits (%) 95.7 97.7 98.1

The average percentage of functionalized chains (in%) is obtained by the formula:

(CH ₂ -Si / PI) * Mn * 1.10 ^"4 with CH ₂ -Si / PI in meq / kg and Mn in g.mol ^{" 1} .

This method of synthesizing polyisoprene according to the invention, in a very concentrated and continuous medium, makes it possible to achieve a high conversion rate of 99%, of which at least 91% in the limit of the first third of the reaction volume of the polymerization reactor 1 In addition, the standard deviation of the residence time distribution function in the polymerization reactor is greater than the average residence time divided by 2Λ / 3. The average functionalization rate (or average percentage of functionalized chains) is also high since it varies from 70% to 100% of functionalized chains. This process is perfectly flexible and adaptable to economically attractive industrial production due to the reduced amount of solvent used while ensuring increased productivity with a high conversion rate.

Evaluation of polyisoprenes prepared in rubber composition

1-Manufacture of Rubber Compositions: All the necessary basic constituents (diene elastomer, reinforcing fillers and coupling agent, plasticizers, other additives), with the exception of the crosslinking system, are successively introduced into a usual internal mixer. Thermomechanical work (non-productive phase) is then carried out in one step, which lasts a total of about 3 to 4 minutes, until a maximum temperature of "fall" of 165 ° C is reached. The mixture thus obtained is recovered and cooled.

 After cooling the mixture thus obtained, the crosslinking system composed of sulfur and sulfenamide (CBS) is then incorporated in an external mixer (homo-fender) maintained at a low temperature. The whole is then mixed (productive phase) for a few minutes (about ten minutes).

The final composition thus obtained is then calendered in the form of a sheet or a plate for a characterization in the laboratory.

2- Measurements and tests:

The rubber compositions are characterized after curing as indicated below.

Dynamic properties are measured on a viscoanalyzer (Metravib VA4000) according to ASTM D 5992-96. The response of a sample of vulcanized composition (cylindrical specimen 4 mm in thickness and 400 mm ² in section) is recorded, subjected to a sinusoidal stress in alternating simple shear, at the frequency of 10 Hz, during a sweeping in temperature, under a fixed stress of 0.7 MPa, the value of tan δ observed at -10 ° C (ie tan (δ) -10 ° C) is recorded. The same sample is also subjected, at a temperature of 40 ° C. or 60 ° C., to a strain amplitude sweep of 0.1% to 50% (forward cycle) and then to 50%> to 1% (return cycle). ): for the return cycle, the maximum value of the loss factor is recorded, denoted tan (ô) max. The non-linearity denoted AG * is the difference in shear modulus between 0.1% to 50% deformation in MPa. It will be recalled that, in a manner well known to those skilled in the art, the value of tan (δ) max (according to a "deformation" sweep at a given temperature) is representative of hysteresis and rolling resistance (plus tan (δ) max is low, hysteresis and thus rolling resistance are lower) while the value of tan (δ) -10 ° C (according to a "temperature" sweep, with a given deformation) is representative of the Wet adhesion potential (more tan (δ) -10 ° C is higher, better adhesion).

3 - Results The compositions and their properties are reported in Tables 3 and 4 below.

Table 3

Composition

 A B C

 Example 1 100

 Example 2 100

 Witness 100

 N234 6 6 6

 Zeosil Silica 1165MP Rhodia 80 80 80

 Coupling agent TESPT (Si69 Degussa) 6.4 6.4 6.4

 PLASTICIZING A 10 10 10

 PLASTICIZER B 25 25 25

 Ozone wax C32ST 1.5 1.5 1.5

 Antiozone Agent (6PPD) 1.9 1.9 1.9

 Diphenylguanidine (DPG) 1 .5 1.5 1.5

 ZnO 2 2 2

 Stearic acid 2 2 2

 Sulfur 1.2 1.2 1.2

 CBS 1.8 1.8 1.8

Plasticizer A: TDAE Oil

Plasticizer B: polylimonene resin: "Dercolyte L120" from DRT Table 4

Composition

 A B C tan (5) max (40 ° C 10Hz) 0.261 0.249 0.293

 DG * (40 ° C 10Hz) 3.44 3.04 4.17

tan (δ) -10 ° C (0.7 MPa 10Hz) 0.71 0.7 0.72

The properties in the vulcanized state of the compositions show that the compositions according to the invention (compositions A and B) have hysteresis properties as well as properties of reinforcement and breaking strength which are greatly improved compared to those of the reference composition implementing a nonfunctionalized IR (composition C), which is very favorable for obtaining a tire having a reduced rolling resistance when the composition according to the invention is used either as a tread, or as a tread underlayer or as a sidewall rubber.

When the composition according to the invention is used as tread, wet grip performance is further maintained (values of tan (δ) -10 ° C close).

ANNEX 1

The inherent viscosity is determined by measuring the flow time (t) of the polymer solution and the toluene flow time (t ₀ ) in a capillary tube. In a tube Ubbelhode (diameter of capillary 0.46 mm, capacity 18 to 22 ml), placed in a bath thermostated at 25 ± 0.1 ° C, the flow time of toluene and that of the polymer solution (Q to 0, 1 g / dl are measured.

The inherent viscosity is obtained by the following relation:

 with:

 C: concentration of the toluene solution of polymer in g / dl;

 t: flow time of the toluene solution of polymer in seconds; to: toluene flow time in seconds;

 inh: inherent viscosity expressed in dl / g.

Claims

Process for the continuous synthesis of a diene elastomer, characterized in that it comprises the following simultaneous stages,

 related to polymerization:

 a) continuously introducing into a polymerization reactor equipped with a gas phase and equipped with at least one stirring device and a discharge device, at least one

 i. a catalytic system of coordination,

 ii. at least one conjugated diene monomer to be polymerized, and iii. from 0% to 70% by weight of an organic solvent, calculated with respect to the total monomer (s) mass and solvent;

 b) continuously polymerizing the monomer (s), by implementing the means necessary to achieve a conversion of at least 60% at the limit of the first third of the reaction volume of the polymerization reactor;

 c) stirring the polymerization medium by the continuous movement of at least one stirring member around a rotary axis;

 d) continuously discharging the pseudo-living elastomer paste resulting from the polymerization;

 the standard deviation of the residence time distribution function in the polymerization reactor being greater than the average residence time divided by 2Λ / 3, related to functionalization:

 e) continuously feed this paste to a mixer having a gas phase, a stirring device to at least one stirring device and a discharge device;

f) continuously introducing into the kneader a functionalizing agent corresponding to the formula A-R 1 -B with A denoting a group capable of reacting on the reactive end of the pseudovivant elastomer, R 1 denoting an atom or a group of atoms forming a bond between A and B, and B denoting a function capable of reacting with a reinforcing filler g) continuously functionalizing the pseudo-living elastomer by reaction with the functionalization agent in said kneader;

 h) continuously discharging the functionalized elastomer paste from the previous step;

 i) recovering the functionalized diene elastomer.

Process for the continuous synthesis of a diene elastomer according to claim 1, characterized in that the conversion ratio is at least 80%, in limit of the first third of the reaction volume of the polymerization reactor.

Process for the continuous synthesis of a diene elastomer according to claim 1 or 2, characterized in that the standard deviation of the residence time distribution function within the polymerization reactor is greater than the average residence time divided by 2.

Process according to any one of the preceding claims, characterized in that the stirring of the polymerization medium is carried out by the continuous movement of two stirring rods.

Process according to Claim 4, characterized in that the stirring machines are sigma-type or Z-shaped blades.

Process according to any one of the preceding claims, characterized in that in step h) the discharged elastomer paste is conveyed to a granulator for cutting said elastomer paste.

7. Method according to claim 6, characterized in that the granulator is a granulator under water.

8. Method according to any one of the preceding claims, characterized in that the mixing device of the mixer sweeps at least 90% of the volume of the kneader, preferably 95%, ensuring self-cleaning.

Process according to any one of the preceding claims, characterized in that the discharge of the elastomer paste in step d) and optionally in step h) is carried out by the combined action of at least a drain screw and a gear pump which constitutes the discharge device.

10. Process according to any one of the preceding claims, characterized in that the group R 1 is a divalent hydrocarbon radical, linear, branched or cyclic, and may contain one or more aromatic radicals, and / or one or more heteroatoms, preferably a divalent aliphatic hydrocarbon radical Ci-Cis, saturated or unsaturated, cyclic or not, which may contain one or more aromatic radicals.

1. Process according to any one of the preceding claims, characterized in that the group A capable of reacting on the reactive end of the pseudo-living elastomer is chosen from epoxides, glycidyloxy, carbonyls and aldehydes. ketones, esters, carbonates, anhydrides, isocyanates, imines, alkoxysilanes, nitriles, aziridines, acyl chlorides, azines, cyclic halosilanes, oximes, ureas, methacrylates, hydrazones, lactones, thiolactones, thiocarboxylic acid esters, nitroso, carbamates.

12. Method according to any one of the preceding claims, characterized in that the function capable of interacting with a reinforcing filler is a functional group comprising one or more functions selected from a primary amine protected or not, secondary protected or not or tertiary , imine, imide, amide, nitrile, azo, carbamate, methacrylate, methacrylamide, hydroxyl, carbonyl, carboxyl, epoxy, glycidyloxy, thiol, sulfide, disulfide, thiocarbonyl, a thioester, a sulfonyl, a silane, a silanol, an alkoxysilane, a di-alkoxysilane, a alkoxysilane, stannyl, tin halide, tin halide alkyl, tin halide aryl, polyether, nitrogen heterocycle, oxygenated heterocycle, sulfur heterocycle and aromatic group substituted by previously mentioned groups.

13. Method according to any one of the preceding claims, characterized in that the catalytic system is based on at least:

(i) an organic rare earth salt,

 (ii) an alkylating agent and, where applicable,

 (iii) a halogen donor, and / or

 (iv) a pre-forming diene monomer,

14. Method according to any one of the preceding claims, characterized in that during step a), is introduced continuously into the polymerization reactor, with a flow different from that of the catalyst system, at least one alkyl aluminum compound of formula A1R ₃ or HA1R ₂ in which R represents an alkyl radical and H a hydrogen atom, which is identical or not to that of said catalytic system.

15. Process according to claim 14, characterized in that prior to step a), the alkylaluminium compound, the solvent and the monomer to be polymerized are brought into contact to form a mixture which is introduced into the polymerization reactor when the step a).

16. Process according to any one of the preceding claims, characterized in that the diene monomer to be polymerized is chosen from butadiene, isoprene or their mixture.

17. Installation for the implementation of a method according to one of the preceding claims, characterized in that it comprises A polymerization reactor (1) equipped with a gas phase and equipped with at least one stirring device and a discharge device, the reactor (1) being at least provided with:

 several inputs respectively connected to a plurality of supply sources including at least one feed source (2) in a catalytic system, a supply source (5) in at least one monomer and, where appropriate, a source of supply (6) of inert hydrocarbon solvent, and

an outlet suitable for discharging from said reactor (1), continuously, the pseudo-living elastomer paste into an outgoing flow connected via a discharge device to a self-cleaning type mixer (11)

a stirring mechanism adapted to the high viscosities of the reaction medium,

 - A discharge device consisting of at least one emptying screw;

 A kneader (11), preferably of the self-cleaning type sweeping at least 90% of the volume of the kneader, as functionalization reactor, at least provided with

 an inlet connected to a supply source of pseudo-living elastomer paste (9) discharged from the polymerization reactor (1),

an input connected to a power source (12) as functionalization agent, and

 - An output adapted to discharge said mixer (11), continuously, the elastomer paste functionalized in a flow out (13) to the device (17) for cutting the elastomer paste.

18. Installation according to claim 17, characterized in that the polymerization reactor (1) is a double-sigma or Z-shaped reactor.

19. Installation according to claim 17 or 18, characterized in that the device (17) for cutting the functionalized elastomer paste discharged from the mixer (11) is a granulator.

20. Installation according to any one of claims 17 to 19, characterized in that the discharge device of the polymerization reactor (1) and / or the mixer (1 1) consists of at least one drain screw to the end of which is connected a gear pump (10) and / or (16).

21. Installation according to any one of claims 17 to 20, characterized in that it comprises a supply source (7) of an alkylaluminium directly connected to the polymerization reactor (1) or connected to the mixture of flows (6). and (5) upstream of the polymerization reactor provided that the supply of the catalyst system (2) is independent of this flow mixture.

22. Installation according to any one of claims 17 to 21, characterized in that at least one of the reactor (1) and the mixer (1 1) is provided with a second outlet to a condenser.

23. Installation according to claim 22, characterized in that at least one of the condensers is provided with an outlet for returning the condensate to the reactor (1).