RU2653851C2 - Method of the functionalized diene elastomer continuous synthesis - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to the functionalized diene elastomer continuous synthesis method. Diene elastomer continuous synthesis method comprises the following simultaneous stages: related to the polymerization stage comprises: a) continuously introducing into the having the gas phase and equipped with at least one stirring rotor and discharge device polymerization reactor, of at least: i. one coordination catalysis system, ii. at least one conjugated diene monomer for polymerization, and iii. from 0 to 70 wt% of organic solvent based on the monomer (s) and solvent total weight; b) monomer (s) continuous polymerization using the means necessary to achieve the conversion degree of at least 60% within the first third of the polymerization reactor reaction volume; c) mixing the polymerization mixture by at least one stirring rotor continuous movement about the axis of rotation; d) pseudo-living elastomer paste continuous unloading obtained as a result of the polymerization; where the residence time distribution function in the polymerization reactor standard deviation is greater than the result of the average residence time division by 2√3, relating to the functionalization stage includes: e) this paste continuous transfer to the having gas phase kneader, stirring device comprising at least one stirring rotor and discharging device; f) functionalizing agent continuous introduction into the kneading machine, corresponding to the AR₁-B formula, where A is the group capable of reacting with the pseudo-living elastomer reactive end, R₁ designates atom or group of atoms forming bond between A and B, and B is functional group capable of interacting with the reinforcing filler; g) pseudo-living elastomer continuous functionalization by interaction with the functionalizing agent in the said kneading machine; h) obtained at the preceding stage functionalized elastomer paste continuous discharging; i) functionalized diene elastomer isolation.

EFFECT: technical result is that this synthesis method is applicable to the highly concentrated mixture, characterized by the increased productivity, in particular by providing a high degree of conversion, which can reach 100% and functionalization degrees of at least 70%, and provides flexibility of the process implementation.

23 cl, 4 tbl, 2 dwg

Description

The present invention relates to a method for the synthesis of modified diene elastomers with a high degree of functionalization in a concentrated mixture. The invention is applicable, in particular, to the continuous production of modified diene elastomers.

Since fuel economy and the need to protect the environment have become a priority these days, it is desirable to obtain mixtures with good mechanical properties and the lowest possible hysteresis, so that they can be processed into rubber compositions that can be used in the manufacture of various semi-finished products included in the composition of the tires.

Many solutions have already been experimentally investigated, the purpose of which was to reduce hysteresis. In particular, mention may be made of the modification of the structure of diene polymers and copolymers using functionalizing agents in order to obtain the proper interaction between the polymer modified in this way and the filler, which is either soot or another reinforcing filler.

There is an extensive literature on the functionalization of polymers obtained by anionic polymerization. Functionalization can be carried out either during the initiation of polymerization using an initiator bearing a functional group to be included in the elastomer chain, or during the postpolymerization reaction using a functionalizing agent. Agents that allow all kinds of functional groups to be introduced into the polymer are known to those skilled in the art and are widely described.

Anionic polymerization allows to some extent to regulate the microstructure of the synthesized polymers. However, by polymerization of this type it is impossible to synthesize polymers having a high content of cis units.

Polymers having a high content of cis units are mainly prepared by coordination catalysis polymerization. There is also a very extensive literature relating to this type of catalysis.

The functionalization of these polymers having a high content of cis units is less widely used as a result of the very nature of the catalyst systems used. Some authors have described the functionalization of polymers obtained by coordination catalysis. In particular, mention may be made of documents WO 0134658 A1, EP 1939221 A1 and EP 1873168 A1. Some of them mention high degrees of functionalization, more than 75%, for polymers obtained using block or semi-block polymerization (EP 1939221 A1).

However, all of these documents relate to polymerization in a batch reactor. Although EP 1939221 A1, with reference to WO 2005087824, briefly touches on the possibility of continuous implementation of the described process, the degree of conversion is low. In WO2005087824, polymerization is carried out in a first reactor up to a maximum degree of conversion of 20%. The polymer is discharged and transferred to a second reactor, in which volatiles can be removed immediately. The result of the restriction to a low degree of conversion of 20% is the low productivity of this method. In addition, non-converting monomer must be removed and processed in order to be introduced back into the first reactor. This treatment is carried out on large volumes of not converted monomer. This aspect of the method makes it not very attractive as a result of energy and economic influence on its cost.

It was found that in the past, methods for modifying a diene polymer having a high content of cis units were mainly carried out in a batch mode after completion of the coordination catalysis polymerization. Indeed, such a periodic method is not always productive and is not always sufficiently competitive and economical for industrial production.

In addition, a reduced amount of solvent may be advantageous for enhancing the economic benefits of polymerization. The benefits of block or semi-block (also known as highly concentrated) polymerization are diverse. For example, the size of parts of equipment, in particular, located outside the reaction site, is reduced as a result of the smaller amount of solvent used, which reduces investment. In addition, the result of this reduction in the amount of solvent or its elimination really is a decrease in the amount of energy (in the form of steam to remove 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 result in lower energy costs of the polymerization process. In addition, the amount of catalyst is usually reduced, which reduces the cost of starting materials.

However, block or semi-block polymerization has a major drawback. It is reflected by the occurrence of a physical phenomenon that can damage the nature of the resulting polymer and create uncontrolled situations in industrial production. This is due to the fact that the evaporation of part of the liquid monomer under the action of the energy of the polymerization reaction leads, as a result, starting from a certain concentration of polymer in the reaction mixture, to excessive expansion of the reaction mixture. Under such operating conditions, the heat of reaction can no longer be controlled, and due to this, the polymer can denature. It is for this reason that some authors prefer relatively low degrees of conversion to avoid this phenomenon, for example, in US 3770710 or in WO 2005087824.

The technical problem to which the invention is directed, is to make available a competitive, economical and flexible synthesis method that is adaptable to industrial production, which allows to obtain a functionalized polymer having a high content of cis units.

One of the objectives of the invention is to make available a method that makes it possible to obtain a functionalized polymer having a high content of cis units, which exhibits a high degree of functionalization.

The next objective of the invention is to make available a method for the synthesis of functionalized diene polymers in a highly concentrated mixture having a high content of cis units, additionally showing increased productivity, while avoiding the phenomenon of expansion of the reaction mixture, and, therefore, allowing flexibility in terms of implementation method, in particular, within a wide range of temperatures.

The present invention solves the technical problem and achieves these goals in the sense that it provides a continuous method, especially suitable for cost-effective industrial production with increased competitiveness. This is due to the fact that the invention proposes a continuous method for the synthesis of a functionalized diene polymer, which includes a step of continuous polymerization in a highly concentrated mixture by coordination catalysis of at least one diene monomer and a step of continuous functionalization of the obtained pseudo-living polymer.

The invention allows to improve the polymerization conditions of conjugated dienes in a highly concentrated mixture in order to be able to achieve a high degree of conversion without the occurrence of the expansion phenomenon of the reaction mixture.

The invention also allows to achieve high degrees of functionalization on elastomers having a high content of cis units.

The invention also provides energy and environmental benefits associated with polymerization in a highly concentrated mixture and the possibility of implementing the method within a wide range of reaction temperatures.

Thus, an object of the invention is a method for the continuous synthesis of a modified diene elastomer, comprising a block or semi-block polymerization step, during which a pseudo-living diene elastomer is synthesized having a high content of cis units, and a functionalization or modification step, during which the pseudo-living diene elastomer interacts with a particular functionalizing agent.

Another object of the invention is an apparatus for the practical implementation of such a method.

The first object of the invention is a method for the continuous synthesis of functionalized diene elastomer, comprising the following simultaneous stages:

- related to polymerization:

a) continuous introduction into the polymerization reactor having a gas phase and equipped with at least one mixing rotor and a discharge device, at least:

i. one coordination catalysis system,

ii. at least one conjugated diene monomer for polymerization, and

iii. from 0 to 70 wt.% organic solvent based on the total weight of monomer (s) and solvent;

b) continuous polymerization of the monomer (s) using the means necessary to achieve a degree of conversion of at least 60% within the first third of the reaction volume of the polymerization reactor;

c) stirring the polymerization mixture by continuously moving at least one stirring rotor about an axis of rotation;

d) continuous unloading of a paste of a pseudo-living elastomer obtained by polymerization;

where the standard deviation of the distribution function of the residence time in the polymerization reactor is greater than the result of dividing the average residence time by 2√3,

- related to functionalization:

e) continuously transferring this paste to a kneading machine having a gas phase, a mixing device comprising at least one mixing rotor, and an unloading device;

f) continuously introducing into the kneading machine a functionalizing agent according to the formula AR ₁ -B, where A is a group capable of reacting with the reactive end of a pseudo-living elastomer, R ₁ is an atom or a group of atoms forming a bond between A and B, and B is a functional a group capable of interacting with a reinforcing filler;

g) continuous functionalization of the pseudo-living elastomer by reaction with a functionalizing agent in said kneading machine;

h) continuous unloading of paste of functionalized elastomer obtained in the previous step;

i) isolation of a functionalized diene elastomer.

Since the method according to the invention is carried out continuously, it should be understood that steps (a) to (i) are performed immediately after loading the polymerization reactor.

In the present description, the expressions “highly concentrated” and “block and semi-block” are used without distinction, since they have the same meaning.

In the present description, the terms “solvent” and “diluent” are used without distinction, since they have the same meaning.

In this description, any range of values indicated by the expression “between a and b” is a range of values that extends from greater than a to shorter than b (that is, the limit values a and b are excluded), while any range of values denoted by the expression “a to b” is a range of values extending from a to b (that is, including strict limit values a and b).

In the present description, the expression "high content of cis units", used in connection with the elastomer, means the molar fraction of inclusion in the chain of cis-1,4 units at least 95% based on the elastomer.

In the present description, the expression "pseudo-living", used in connection with an elastomer, means that all ends or part of the ends of the chain of the elastomer are reactive, in particular with respect to functionalizing agents.

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

It should be noted that the combination of flow and conversion characteristics is one of the essential elements of the invention, which allows, due to the continuous polymerization method, to solve the technical problem posed for polymerization in a highly concentrated mixture, adaptable to cost-effective industrial production with satisfactory productivity, more specifically, to avoid the phenomenon of expansion of the reaction mixtures.

According to a specific embodiment of the synthesis method according to the invention, the polymerization is carried out continuously, the amount of solvent not exceeding 70 wt.% Of the total mass of monomer (s) and solvent, while the amount of solvent can be, for example, at least 10 wt.%, Actually at least 30 wt.%, and a maximum of 60 wt.%, in fact, even a maximum of 55 wt.% of the total weight of the monomer (s) and solvent.

According to another embodiment of the invention, the polymerization is carried out without the addition of a polymerization solvent.

The choice of the polymerization reactor is, as a result of these possibilities for practical implementation, a particularly important aspect of the method according to the invention. This is due to the fact that it is desirable to polymerize the monomers in a highly concentrated mixture. According to the invention, the term "highly concentrated mixture" should be understood as meaning the concentration of monomer (s) in the mixture of solvent and monomer (s) of at least 30 wt.%, While this concentration can reach 100 wt.% In the absence of solvent. In addition, it is desirable to carry out the polymerization to obtain high degrees of conversion at the boundary of the first third of the reaction volume of the polymerization reactor at least 60%, which can reach 100%.

The viscosity of the polymerization mixture, essentially consisting of monomers, an elastomer and, if necessary, a solvent, can reach high values. The intrinsic viscosity of a diene elastomer depends on its nature. It has a minimum value of at least 1.5 dl / g, in fact even at least 4 dl / g, in particular for polyisoprenes prepared by coordination catalysis. However, the intrinsic viscosity preferably does not exceed 10 dl / g, in fact even 7 dl / g. The intrinsic viscosity is determined in accordance with the method described in Appendix 1.

Stirring inside the polymerization reactor should knead this highly viscous mixture in order to synthesize a polymer of stable and homogeneous quality.

In addition to compatibility with high viscosities, the reactor should be suitable for continuous polymerisation of the monomer (s), and should allow flow in the form of a highly concentrated mixture, in fact even a volume stream, so that the standard deviation of the distribution function of the residence time in the polymerization reactor was larger than the result of dividing the average residence time by 2√3.

A stirring rotor allows continuous mixing of the reaction mixture. It can be of various shapes and adapts to reactor technology.

On sale you can find many types of mixing rotors. As an example, the rotor may be a sigmoid (or "Z-shaped") blade or another type of blade, as described in the books: David B. Todd, Mixing of Highly Viscous Fluids, Polymers, and Pastes; Handbook of Industrial Mixing: Science and Practice, E.L. Paul, V.A. Atiemo-Obeng and S.M. Kresta, Editors, 2004, John Wiley and Sons, c. 998, c. 1021.

When the reactor is equipped with at least two mixing blades, they can be oppositely rotating or rotating in the same direction. In addition, they can be of tangential or interpenetrating type.

According to certain configurations, the polymerization reactor is equipped with a stirring rotor. So, this type of reactor can be formed from a tank, a mixing rotor and a discharge device. For example, as a reactor suitable for the invention, mention may be made of a reactor sold by LIST AG as a single rotor kneading machine.

In accordance with other configurations, the polymerization reactor is equipped with two mixing rotors.

In accordance with the configurations described above, the polymerization reactor may be formed from a tank, a mixing system and a discharge device.

In accordance with preferred configurations, the polymerization reactor is more particularly a Z-shaped kneading machine. The term “Z-shaped kneading machine” is more specifically understood to mean a mixer or kneading machine formed from a tank equipped with two Z-shaped blades, each of which is independently driven around an axis of rotation, preferably a horizontal axis of rotation. Thus, the two Z-shaped vanes are preferably driven in the opposite direction of rotation so that in the pressure mode they feed into the unloading device at the bottom of the tank.

As an example, this reactor in accordance with the invention is sold under various names, such as:

- kneading machines with a multi-blade mixer and a screw type discharge device, sold by Battaggion SPA,

GmbH & Co. KG,- extruder kneading machines sold by Aachener Misch- und Knetmaschinenfabrik Peter

GmbH & Co. KG,

- Z-shaped twin-blade kneading machines with screw extruder sold by Hermann Linden Maschinenfabrik GmbH & Co. KG,

- extruder mixers sold by Aaron Process Equipment Company.

The polymerization reactor has a gas phase, which allows the heat of polymerization to be discharged by evaporation of part of the reaction mixture. The ratio of the volume of the gas phase to the reaction mixture depends on the type of reactor used, and its determination is within the competence of a person skilled in the art.

According to one embodiment of the invention, the polymerization is carried out in a block. In this case, no polymerization solvent is added.

According to other forms of the invention, the polymerization is carried out in semi-block conditions. In this case, the mixture contains a hydrocarbon polymerization solvent, a preferred aliphatic or epicyclic hydrocarbon polymerization solvent having a low molecular weight, in particular for environmental reasons. Mention may be made, for example, of n-pentane, isopentane, isoamylenes (2-methyl-2-butene, 2-methyl-1-butene and 3-methyl-1-butene), 2,2-dimethylbutane, 2,2-dimethylpropane ( neopentane), n-heptane, n-octane, isooctane, cyclopentane, cyclohexane, n-hexane, methylcyclopentane and methylcyclohexane, as well as mixtures of these compounds, with n-pentane being particularly preferred. Aromatic hydrocarbons such as, for example, benzene or toluene can also be mentioned among the solvents.

The solvent may be added directly to the reactor. It can also be pre-mixed with at least one of the other components introduced into the polymerization reactor, in particular with the monomer (s) for polymerization. This latter embodiment is a preferred embodiment in accordance with the invention.

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

The term “conjugated diene monomer” is understood to mean a conjugated diene monomer having from 4 to 16 carbon atoms. Suitable conjugated dienes are, in particular, 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 or 2-methyl-3-isopropyl-1,3- butadiene, phenyl-1,3-butadiene, 1,3-pentadiene, 2,4-hexadiene, myrcene and the like.

In accordance with embodiments of the method of the invention, the conjugated diene monomer can be polymerized together with one or more than one conjugated diene monomer.

In accordance with one embodiment of the process of the invention, the conjugated diene monomer can be introduced in the form of a hydrocarbon fraction containing monomer or monomers for polymerization.

The choice of monomers is determined by the desired polymer. Coordination catalysis polymerization is carried out using a rare earth metal, titanium or other transition metal catalyst system.

In the context of this coordinated catalysis chain polymerization, a rare earth metal or titanium catalyst system is used.

Such catalyst systems are fully described in the literature.

As an example, such a catalytic system can be obtained based on at least:

- one organic salt of a rare earth metal,

- one alkylating agent and, if necessary,

- one halogen atom donor and / or

- one preformed conjugated diene monomer.

The expression "based on" when used to determine the components of the catalyst system is understood to mean the reaction product or products of these components after preliminary mixing of all or part of the components or, if necessary, after preliminary formation and / or aging of the catalyst system, or also the product or products of the interaction of these components in situ.

The catalytic system can be obtained in batch or continuous mode. In accordance with one embodiment of the method of the invention, an apparatus for continuously synthesizing a catalyst system continuously fed into the polymerization reactor is located in front of the polymerization reactor. The catalyst system can be introduced directly into the reactor or pre-mixed with at least one of the other components that are fed to the polymerization reactor.

In accordance with the invention, the term "rare earth metal" is understood to mean a metal selected from yttrium, scandium and lanthanides, metals having an atomic number in the range from 57 to 71 inclusive in the Periodic Table of the Elements. Preferably, the rare earth metal is selected from lanthanides, where neodymium is more particularly preferred.

The term "organic salt of a rare earth metal" is understood to mean, for example, tris (carboxylates), tris (alcoholates), tris (acetylacetonates) or tris (organophosphates) of rare earth metals.

When the organic rare-earth metal salt is tris (carboxylate) of the rare-earth metal, the carboxylate may be selected from linear or branched aliphatic carboxylic esters having 6 to 16 carbon atoms in a linear chain and aromatic carboxylic esters containing from 6 to 12 carbon atoms, substituted or unsubstituted. Mention may be made, for example, of neodecanoate (versatate), octoate or hexanoate, which are linear or branched, or also naphthenate, which is or is not substituted. Among them, 2-ethylhexanoate, naphthenate or neodecanoate (versatate) of the rare earth metal is particularly preferred.

When the organic rare earth metal salt is tris (alcoholate) of the rare earth metal, the alcoholate may be selected from alcohol alcohol or a polyol formed from an aliphatic or cyclic hydrocarbon, and in particular from a linear or branched aliphatic hydrocarbon having from 1 to 10 carbon atoms in a linear chain, more specifically from 4 to 8 carbon atoms. Mention may be made, for example, of neopentoxide.

When the organic rare earth metal salt is tris (organophosphate) of the rare earth metal, the organophosphate may be selected from phosphoric acid diesters of the general formula (R'O) (RʺO) PO (OH), where R 'and Rʺ, which are the same or different, are is an alkyl, aryl or alkylaryl radical. Mention may be made, for example, of 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-ethylhexylphosphate] neodymium, tris [1-methylheptyl-2-ethylhexylphosphate] neodymium, tris [2-ethylhexyl-p-nonylphenylphosphate] neodymium, tris [bis (2-ethylhex ) phosphate] neodymium, tris [bis (oleyl) phosphate] neodymium or tris [bis (linearol) phosphate] neodymium.

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

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

The rare earth metal salt is usually dissolved or suspended, as the case may be, in an inert hydrocarbon solvent selected, for example, from low molecular weight aliphatic or al and cyclic solvents, such as, for example, cyclohexane, methylcyclohexane, n-heptane, pentane or mixtures these solvents.

As the alkylating agent that can be used in the catalytic system according to the invention, mention may be made of alkyl aluminum selected from trialkyl aluminum or from dialkyl aluminum hydrides, where the alkyl group contains from 1 to 10 carbon atoms. As trialkyl aluminum, mention may be made of triethyl aluminum, triisopropyl aluminum, triisobutyl aluminum, tributyl aluminum or trioctyl aluminum.

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

When the catalyst system contains a halogen atom donor, an alkyl halide, an alkyl aluminum halide or an alkyl aluminum sesqui-halide can be used. Preferably, an alkyl aluminum halide is used where the alkyl group contains from 1 to 8 carbon atoms. Among them, diethyl aluminum chloride is preferred.

According to a specific characteristic of the catalyst system, rare earth metal or metals are present in the catalyst system in accordance with a concentration equal to or greater than 0.005 mol / L, and preferably in the range of 0.010 to 0.1 mol / L, and more preferably in the range of 0.02 mol / l to 0.08 mol / l.

In accordance with alternative forms of the invention, the molar ratio (alkylating agent / rare-earth metal salt) in said catalyst system preferably has a value of at least 1 and not more than 50. In accordance with some alternative forms of the method of the invention, this ratio is a maximum of 30, in fact even maximum 15. According to other alternative forms of the method according to the invention, this ratio is at least 4.

In accordance with alternative forms of the invention, the molar ratio (halogen atom donor / rare earth metal salt) is from 0.5 to 5, preferably from 2 to 3.6, and even more preferably from 2.5 to 3.2.

When the catalyst system contains a preformed conjugated diene monomer used to “pre-form” said catalyst system, it may be selected from the aforementioned conjugated diene monomers. 1,3-butadiene or isoprene are particularly preferred.

In accordance with alternative forms of the invention, the molar ratio (pre-prepared monomer / rare earth metal salt) has a value of at least 5, preferably at least 10 and not more than 100, preferably not more than 90. In accordance with some alternative forms, this ratio has a value in the range from 15 to 70, in fact, even from 25 to 50.

These preferred alternative forms and aspects, although they vary, can be combined with each other if they relate to the nature of the components of the catalytic system or to their ratio.

As a preformed or preformed catalyst system in the context of the present invention, the systems described in WO-A-02/38636, WO-A-03/097708, WO-A-2007045417 and PCT / EP2013 / 075437 on behalf of the companies are applicable. - applicants.

According to alternative embodiments of the catalytic polymerization process of the invention, a predetermined additional amount of at least one alkyl aluminum compound of the formula AlR ₃ or HAlR ₂ or Rʺ can be introduced into the polymerization reactor by means of a stream independent of the introduction of the catalytic system used for the polymerization _n AlR _'3-n, where R and R' represent saturated or unsaturated alkyl group of from 1 to 20 carbon atoms, preferably from 1 to 12 carbon atoms, R" presents t ulation an allyl group, and n represents an integer from 1 to 3 inclusive. Such alternative forms are described, in particular, in documents WO 2006133757, EP 1845118, WO 10/069511 and WO 10/069805.

As the alkylaluminum compound, mention may be made of alkylaluminums such as:

- trialkylaluminum, such as, for example, trimethylaluminum, triethylaluminum, tri (n-propyl) aluminum, triisopropylaluminum, tri (n-butyl) aluminum, tri (tert-butyl) aluminum, triisobutylaluminum, three (n-pentyl) aluminum, three ( n-hexyl) aluminum or tricyclohexylaluminum, preferably triisobutylaluminum, or

- dialkylaluminum hydrides, such as, for example, diethylaluminum hydride, diisopropylaluminum hydride, di (n-propyl) aluminum hydride, diisobutylaluminum hydride, di (n-octyl) aluminum hydride or di (n-butyl) aluminum hydride, preferably diisobutylaluminum.

Preferably, the molar ratio (alkylaluminum compound added as a complement / trialkylaluminum in the catalyst system) varies from 1/20 to 50/1, preferably ranges from 1/15 to 30/1, and even more preferably ranges from 1/10 to 20/1 .

It should be noted that the addition of an alkylaluminum compound before polymerization eliminates the variation in time of the impurity content due to solvents and monomers introduced at the inlet of the line and does not result in harmful effects on the activity of the catalytic system as a result of these vibrations. Thus, this alternative embodiment of the invention makes it possible to minimize the variation in the characteristics of the resulting elastomer.

This alternative form can be combined with all alternative forms and implementations of the invention, preferred or not, described above or below.

According to one embodiment of the polymerization process of the invention, all components of the starting reaction mixture, that is, polymerization monomers, an optional solvent, a catalytic system and, optionally, additional alkylaluminum, can be separately introduced directly into the polymerization reactor.

According to other forms of implementing the method according to the invention, at least two components of the initial reaction mixture are not separately introduced directly into the polymerization reactor. The mixing of these components can be achieved using various means known to specialists in this field of technology, such as static mixers, dynamic mixers or ultrasonic mixers. Before entering the polymerization reactor, the mixture can be brought to a certain temperature.

The second stage of the method according to the invention relates to the polymerization of diene monomers to (1) achieve a high degree of conversion of at least 60%, within the first third of the volume of the reaction mixture of the polymerization reactor with (2) a standard deviation of the distribution function of the residence time in the polymerization reactor, large than the result of dividing the average residence time by 2√3.

According to the method according to the invention, the degree of conversion of the monomer to produce a polymer is at least 60% within the first third of the volume of the reaction mixture of the polymerization reactor. The term "volume of the polymerization reactor" is understood as meaning the volume available in the reactor from the moment the reactants arrive until the reactor exits, excluding the unloading device.

This limited degree of conversion of 60%, combined with a specific characteristic related to the distribution function of the residence time according to the invention, is essential for overcoming the formation of foam and preventing the phenomenon of expansion of the reaction mixture. This is due to the fact that below 60% and without satisfying the condition associated with the distribution function of the residence time according to the invention, bubble formation is observed, which as a result quickly leads to uncontrolled expansion of the reaction mixture. To achieve this necessary degree of conversion of at least 60%, various technical means of influence or devices are available to a person skilled in the art, which he can change in numerous combinations. Among these technical means of influence, mention may be made of the reaction temperature, the concentration of monomer in the reaction mixture, the concentration of catalyst in the reaction mixture, average residence time, and the like. The devices used to achieve at least 60% conversion within the first third of the volume of the reaction mixture of the polymerization reactor are within the competence of a person skilled in the art. A simple instruction to achieve a minimum conversion limit, in this case at least 60%, within the first third of the volume of the reaction mixture of the polymerization reactor, for a person skilled in the art is to identify combinations of devices used to carry out this instruction.

The degree of conversion can be determined in various ways known to the person skilled in the art. For example, the degree of conversion can be determined based on measurements taken on a sample taken within the first third of the volume of the reaction mixture of the polymerization reactor, for example, by gas chromatography (GC). Measure the concentration of residual (s) (not converted) s of monomer (s) in the sample. The conversion in terms of the weight percent determined based on a difference between the concentration of monomer (s) input (s) to the polymerization reactor (C _i), and the concentration residue (s) of monomer (s), measured in the selected sample (C _r), with using the equation:

where X wt.% - the degree of conversion in the form of mass percent;

C _i is the concentration of monomer or monomers introduced into the polymerization reactor;

C _r is the concentration of residual monomer or monomers measured in the selected sample.

Preferably, this conversion is at least 80% and even more preferably from 85 to 100% to increase productivity.

de la

chimique: conception et fonctionnement des

[Chemical reaction engineering: design and operation of reactors]. Editors. 1993, TEC & DOC - LAVOISIER, стр. 170-172.The process of the invention is also characterized by flow conditions in the reactor during the polymerization reaction. Using the distribution function of the residence time, these flows are characterized so that the standard deviation of the distribution function of the residence time is greater than the result of dividing the average residence time by 2√3. More specifically, the standard deviation of the residence time distribution function is greater than the result of dividing the average residence time by 2. The distribution function of the residence time in the polymerization reactor can be determined by a method that is known per se to a person skilled in the art. For example, it can be determined by modeling experimental points obtained by measuring gas concentration changes in the indicator concentration at the outlet of the reactor after very quickly introducing this indicator in accordance with the method of pulsed introduction of a chemically inert product in accordance with the principle described in the book by Jacques Villermaux,

de la

chimique: conception et fonctionnement des

[Chemical reaction engineering: design and operation of reactors]. Editors. 1993, TEC & DOC - LAVOISIER, pp. 170-172.

The combination of these two characteristics, the degree of conversion and flow, is one of the essential elements of the invention. Thus, in the present invention, a method for synthesizing diene polymers in a highly concentrated mixture and in a continuous mode is available, having increased productivity and marked flexibility as a result of the lack of expansion.

The heat of the polymerization reaction is controlled mainly by at least partial evaporation of the constituents of the non-polymer phase of the reaction mixture. The regulation of the heat of the polymerization reaction by evaporation of part of the components of the non-polymer phase of the reaction mixture provides that the free space (permanent or temporary) above the mixture is capable of receiving the gas phase, as defined above. In order to control the temperature of the reactor and thus control the release of heat generated by the polymerization reaction, several configurations can be considered.

Thus, in accordance with one of the alternative forms, an internal capacitor can be installed in the gas phase of the reactor.

In accordance with another alternative form, an external condensing circuit is used. In accordance with this alternative form, part of the gas phase formed by evaporation of the reaction mixture during the polymerization is entrained through the outlet of the reactor into the condenser. Subsequently, the condensate can preferably be introduced back into the reactor, in whole or in part, as a substitute for part of the solvent and / or monomers in the mixture of at least one monomer and solvent, or stored for later use. In the latter case, accordingly, it is advisable to re-adjust the flows entering the reactor or leaving the polymerization reactor so as to keep the volume of the reaction mixture or the residence time in the reactor constant. You can install a device for removing non-condensable products, either from the reactor or from the condensation circuit, depending on the alternative forms used to control the heat of reaction.

In accordance with yet another alternative form, the heat of the polymerization reaction can also be partially controlled by cooling, which is introduced by the starting components introduced into the polymerization reactor when the temperature at which these components are located is lower than the temperature of the reaction mixture. Thus, the temperature of the starting components introduced into the polymerization reactor can be controlled between -5 ° C and the ambient temperature.

According to other alternative forms, the heat of the polymerization reaction can also be partially controlled by cooling by means of shells or stirrers of the reactors.

These various alternative forms can be combined with each other, while knowing that, since the method is carried out continuously, the combined alternative forms are carried out simultaneously. Preference will be given to at least an alternative form of external condensation circuit, since the exchange surface is not limited to the space available inside the reactor.

The polymerization is carried out in a reactor under conditions of thermodynamic equilibrium between the polymerization mixture and the gas phase. Thus, in accordance with a specific embodiment of the method according to the invention, it is preferable to set the gas pressure in the reactor, which is more reactive than the temperature control, and it is possible to maintain the reaction mixture at the selected pressure and, therefore, as a result of thermodynamic equilibrium at the selected temperature.

In accordance with one embodiment of the process of the invention, the polymerization reaction can also be carried out in vacuo, in which case it can be connected to a vacuum system, preferably on an external condensing circuit.

Very low absolute pressure values make it possible to carry out polymerization at a very low temperature, and these operating conditions are preferred, in particular, for the synthesis of certain diene elastomers.

Typically, the polymerization is carried out at a temperature within the range from -30 to 100 ° C. The flexibility of the method preferably allows the ability to work at temperatures between 20 and 60 ° C, which does not require large expenditures of energy, but, nevertheless, does not adversely affect the performance of the method.

During the polymerization step of the monomer or monomers, the reaction mixture, which can achieve high viscosity, is maintained with stirring by moving around the axis of rotation, preferably the horizontal axis of rotation, the mixing rotor or rotors of the polymerization reactor.

Another stage of the invention consists in continuously unloading part of the reaction mixture in the form of an elastomer paste containing a synthesized pseudo-living elastomer. This continuous unloading is carried out using a discharge device, fully or partially integrated into the polymerization reactor, such as a gear or screw type discharge device, located at the bottom or side of the reactor. At the outlet of the reactor, additional devices can be installed to control the speed of the stream leaving the reactor. Thus, in accordance with a specific alternative form of the invention, the elastomer paste is discharged due to the combined action of at least one discharge screw and gear pump, which together constitute the discharge system, by means of the force transmitted to the gears by the discharge elastomer paste by means of a screw device. Thus, it is preferably possible to maintain the flow rate leaving the reactor equivalent to the flow rate entering the reactor in order to guarantee continuous operation at a constant residence time.

When the discharge device comprises a screw, it may be single or twin screw.

According to another step of the method of the invention, the pseudo-living elastomer solution discharged in step d) is continuously transferred (step e)) to a kneading machine having a gas phase having at least one mixing rotor and having an unloading device for functionalization therein ( step g)) by means of a functionalizing agent continuously introduced into said kneading machine (step f)).

This kneading machine is predominantly self-cleaning. The term "self-cleaning" is understood as meaning in accordance with the invention the fact that its mixing system captures at least 90% of the volume of the kneading machine, preferably 95% of the volume. Among the kneading machines that may be considered, mention may be made of continuous kneading machine reactors equipped with a discharge device comprising at least one screw, and in particular continuous mixing kneading machines with a twin screw discharge device. Such kneading machines are sold, for example, by LIST AG under the name twin screw mixing reactor or also Buss-SMS-Canzler under the name twin large horizontal screw processors.

According to the invention, in step f), a functionalizing agent capable of reacting with a pseudo-living elastomer obtained upon completion of the coordination catalysis polymerization is continuously introduced into the kneading machine.

The functionalizing agent corresponds to the formula AR ₁ -B, where A is a group capable of reacting with the reactive end of a pseudo-living elastomer, R ₁ is an atom or a group of atoms forming a bond between A and B, and B is a functional group capable of reacting with a reinforcing filler .

The group R _{1 is} preferably a linear, branched or cyclic divalent hydrocarbon radical and may contain one or more aromatic radicals and / or one or more than one heteroatom. The specified radical R ₁ may be optionally substituted, provided that the substituents are inert with respect to the reactive ends of the pseudo-living elastomer.

According to preferred alternative forms, the group R ₁ is a saturated or unsaturated and cyclic or non-cyclic divalent C ₁ -C ₁₈ aliphatic hydrocarbon radical, which may contain one or more aromatic radicals.

In accordance with alternative forms of the invention, the term “group capable of reacting with the reactive end of a pseudo-living elastomer” is understood as meaning a group selected, in particular, from epoxides, glycidyloxy, carbonyls, aldehydes, ketones, esters, carbonates, anhydrides, isocyanates, imines, alkoxysilanes, nitriles, aziridines, acid chlorides, azines, cyclic halogenosilanes, oximes, ureas, methacrylates, hydrazones, lactones, thiolactones, thiocarboxylic acid esters, nitroso or ka Bamat.

In accordance with alternative forms of the invention, the term “functional group capable of interacting with a reinforcing filler” is understood to mean a functional group containing one or more functional groups selected from a protected or unprotected primary amine, a protected or unprotected secondary amine, tertiary amine, imine, imide, amide, nitrile, azo, carbamate, methacrylate, methacrylamide, hydroxyl, carbonyl, carboxyl, epoxy, glycidyloxy, thiol, sulfide, disulfide, thiocarbo sludge, thioester, sulfonyl, silane, silanol, alkoxysilane, dialkoxysilane, trialkoxysilane, stannyl, tin halide, tin alkyl halide, tin aryl halide, polyether, nitrogen-based heterocycle, aromatic ring and heterocycle the above groups.

The various aspects, preferred or not, described above and relating, in particular, to the nature of group A, group R ₁ and functional group B, can be combined with each other. Thus, depending on the difficulty of synthesis and on the availability, but especially depending on the type of reinforcing fiber considered in combination with the modified elastomer, one skilled in the art knows which combinations, in particular, combinations of the above groups A and B are particularly preferred.

For example, in accordance with certain alternative forms, glycidyloxy, epoxy, aldehyde, ketone, ester, alkoxysilane, isocyanate, aziridine, and acid chloride groups may be preferred as a group capable of reacting with the reactive end of the pseudo-living elastomer.

In accordance with some alternative forms, it is also possible, for example, to prefer an imine functional group, a protected or unprotected primary amine, a protected or unprotected secondary amine or tertiary amine functional group, or a mono-, di- or trialkoxysilane functional group, optionally substituted with an amine functional group group, as a functional group capable of interacting with a reinforcing fiber.

In accordance with some alternative forms, it is also possible to prefer a C ₁ -C ₁₈ alkyl radical as a group forming a bond between A and B.

Functionalizing agents such as (3-glycidyloxypropyl) methyldiethoxysilane, (3-glycidoxypropyl) -trimethoxysilane, N- (3-triethoxysilylpropyl) -4,5-dihydroimidazole, (2- (3,4- epoxycyclohexyl) ethyl) trimethoxysilane, (3- (meth) acryloyloxypropyl) trimethoxysilane, tris (3-triethoxysilylpropyl) isocyanurate, isocyanatopropyltriethoxysilane, bis (2-ethylhexylmethyl) dioctyltin, (3-triethylpropyl) dimethylaminopropyl) triethoxysilane, bis (benzyl oleate) dibutyltin, 4,4'-bis (diethylamino) benzophenone, N, N'-dimethylimidazolidinone, dichloronaphthoquinone, diethylaminobenzaldehyde, 4,4'-diphenylmethane diisocyanate, polymethylenepolyphenylpolyisocyanate, 1,3-di-isomethylene butyl aziridine, trimethylolpropantris [3- (1-aziridinyl) propionate], butyryl aziridine, 2- (4-morpholinodithio) benzothiazole, N-oxidiethylene-2-benzothiazolsulfenamide, 2-benzothiazyl ether-4-dimethylbylamino-dimethyloamide -morpholinecarbonyl chloride. Among these functionalizing agents, (3-glycidyloxypropyl) -methyldiethoxysilane is particularly preferred.

The functionalization step is carried out by reacting at least one functionalizing agent described above with a solution of a pseudo-living elastomer at a temperature within the range of -30 ° C to 100 ° C. In accordance with some preferred alternative forms, functionalization can be carried out at temperatures between 40 ° C and 70 ° C.

For its part, the reaction time is at least 10 minutes.

The amount of functionalizing agent can vary over a wide range. In accordance with alternative forms of the invention, the molar ratio (functionalizing agent / total aluminum) is at least 1/1 and not more than 10/1, preferably not more than 5/1, in fact not more than 2/1. Total aluminum refers to the total amount of aluminum present in the reaction mixture, taking into account the aluminum included in the alkylating agent and, if necessary, the aluminum included in the additional alkylaluminum compound, added as a complement to the catalyst system

In accordance with one embodiment of the invention, a kneading machine can, together with functionalization, be used to concentrate the reaction mixture by selecting, if necessary, a portion of the solvent and / or unreacted monomers. Then use the condensation circuit. This circuit operates in the same way as the polymerization reactor circuit described above. The condensate stream can preferably be introduced back into the entire upward flow or to the upstream part of the first reactor to partially replace the solvent and / or monomers in the mixture of at least one monomer or solvent, or stored for later use.

In accordance with another embodiment, the kneading machine can also be used in conjunction with functionalization to remove volatiles from the reaction mixture by selecting, if necessary, a solvent and / or unreacted monomers. Then use the condensation circuit. This circuit works in the same way as the polymerization reactor circuit described above. The condensate stream can advantageously be reintroduced into the entire upstream stream or into a portion of the upstream stream of the first reactor to partially replace the solvent and / or monomers in the mixture of at least one monomer or solvent, or stored for subsequent use.

In accordance with a preferred embodiment of the invention, the kneading machine is intended to be functionalized without jointly conducting a concentration or removal of volatiles reaction.

It is understood that, as far as the continuous method is concerned, these various stages, when combined, are carried out simultaneously. The elastomer paste obtained as a result of this functionalization step (step g)) is continuously discharged from this kneading machine (step h)). This continuous unloading is carried out by means of the device with which the kneading machine is equipped. At the output of the unloading device, additional devices for transporting products can be installed to control the speed of the outgoing stream. Thus, in accordance with a particular alternative form of the invention, the paste is unloaded by the combined action of at least one discharge screw and gear pump, which together constitute the discharge system, by the force transmitted to the gears by the elastomer paste being discharged by means of a screw device.

At this stage and in accordance with an alternative form of the invention, the method for synthesizing a functionalized diene elastomer can be continued in a manner that is known per se. Thus, in accordance with one embodiment, a polymerization inhibitor and an antioxidant can be introduced at this stage.

Another stage of the method according to the invention consists in cutting the unloaded paste functionalized elastomer. The elastomer paste is transferred to a device designed to cut it. This type of device is preferably a granulator, which allows you to convert the paste into particles having various shapes and average volumes ranging from 0.07 to 12 cm ³ .

The granulation step can be carried out under various conditions that are known to the person skilled in the art and which are suitable for the method according to the invention. For example, granulation can be carried out under water, which makes it possible to feed the elastomer paste particles to the solvent removal step by steam stripping, or also in the gas phase, which allows the elastomer paste to be fed to the solvent removal step from the elastomer paste particles by drying other than stripping water vapor. According to a preferred aspect, the granulation is carried out under water. As an example, this type of underwater pellet mill is sold under various names, for example, Underwater Pelletizers sold by Gala Industries or Underwater Pelletizing sold by Kreyenborg Industries.

Subsequently, the method is continued in a known manner, consisting in the separation and isolation of the obtained functionalized diene elastomer. Unreacted monomers and / or solvent present in the elastomer paste in particulate form can be removed in accordance with methods known to those skilled in the art.

The functionalized elastomer isolated at the end of these various stages can subsequently be processed in a known manner, for example in the form of balls.

The method according to the invention makes it possible by coordination catalysis to continuously synthesize functionalized elastomers characterized by a molar content of cis units of at least 95% with respect to the elastomer and an average percentage of functionalized chains of at least 70%, which can reach 100%. This synthesis also provides energy and environmental benefits related to polymerization in a highly concentrated medium, while providing increased productivity with a degree of conversion of more than 60%.

Another object of the invention is any installation intended for the practical implementation of the method of continuous synthesis of functionalized diene elastomer and suitable for use on an industrial scale.

By way of illustration and without limitation, an apparatus for the continuous synthesis of a functionalized diene elastomer in accordance with an embodiment of the synthesis method of the invention is more specifically described with reference to FIG. 1, which is an installation diagram for the practical implementation of the method.

FIG. 1 is a diagram of an apparatus in accordance with one embodiment of the invention for the continuous synthesis of a diene elastomer by coordination catalysis, including a polymerization reactor, a self-cleaning kneading machine, and a granulator.

The installation illustrated in FIG. 1 essentially includes a polymerization reactor 1, which has a gas phase and is equipped with at least one mixing rotor, preferably containing two Z-shaped blades, and a discharge device containing at least one screw. In addition, reactor 1 is characterized by a certain flow such that the distribution function of the residence time is such that the standard deviation of this function is greater than the result of dividing the average residence time by 2√3, preferably more than the result of dividing the average residence time by 2.

The polymerization reactor 1 is connected at least:

- with several sources of continuous supply, including at least one source 2 for supplying a catalytic system and a source 3 for supplying at least one monomer, optionally mixed with an inert hydrocarbon solvent, and

- with an outlet adapted for continuous unloading from the said reactor 1 of elastomer paste in the form of a stream exiting through the unloading device.

According to an alternative form of installation illustrated in FIG. 1, the polymerization reactor 1 is connected to a supply source 3 of a mixture of at least one monomer and a solvent. The mixer 4, located above the polymerization reactor 1, makes it possible to obtain this mixture. In this mixer 4, at least one monomer is fed from source 5 and from solvent source 6, and it is connected to the polymerization reactor 1.

According to alternative embodiments of the catalytic polymerization process of the invention, a predetermined additional amount of at least one alkyl aluminum compound can be introduced into the polymerization reactor through a separate stream independent of the introduction of the catalytic system used for the polymerization reaction. According to an alternate form of installation illustrated by dashed lines in FIG. 1, the polymerization reactor 1 is also connected to a source 7 to supply additional alkylating agent. An alkylating agent may alternatively be added to the monomer-solvent mixture before entering the reactor 1, wherein the source 7 for supplying an additional alkylating agent is connected to the source 3 for feeding the monomer and solvent, as indicated by a dotted line in FIG. 1. Indeed, according to yet another alternative, also illustrated in FIG. 1 by dashed lines, the alkylating agent can be introduced directly into the mixer 4 to mix with the monomer and with the solvent, while the source 7 for supplying an additional alkylating agent is connected to the mixer 4.

According to an alternative form of installation illustrated in FIG. 1, a catalyst system supply 2 can be connected to a plant, not illustrated, for continuously feeding the catalyst system, as described in EP 1968734 A1.

The polymerization reactor 1 is equipped with a discharge device containing at least one screw, which allows continuously discharging the elastomer paste in the form of an exit stream 9. This discharge device consists of at least one discharge screw integrated in the reactor 1 and a gear pump 10 below the reactor 1.

In accordance with some forms of the polymerization process, the heat of the polymerization reaction is controlled by at least partially evaporating the non-polymer components of the reaction mixture. In FIG. 1, where an alternative form of this method is illustrated, the polymerization reactor 1 is equipped with a condensation circuit, which makes it possible:

- condensation by means of a capacitor 8 of the gases generated in the reactor 1, and

- return of all condensate or part thereof to the reactor 1.

In accordance with an optional, non-illustrated embodiment of the invention, the condensing circuit may preferably be connected to a device allowing the removal of non-condensable products in a manner that is known per se.

The installation also includes a kneading machine 11 below the polymerization reactor 1 and is connected to it by means of a gear pump 10. The kneading machine 11 has a mixing device that captures at least 90% of the volume of the kneading machine, preferably 95% of its volume, thus ensuring self-cleaning .

The kneading machine 11 is equipped with at least:

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

- an inlet connected to a source 12 for supplying a functionalizing agent,

- an outlet adapted for the continuous unloading from the said kneading machine 11 of a paste of functionalized elastomer in the form of a stream 13 exiting in the direction of the pump 16.

The kneading machine 11 is equipped with an unloading device containing at least one screw, allowing continuous unloading of the pastes of the functionalized elastomer in the form of an effluent 13. This unloading device consists of at least one unloading screw built into the kneading machine 11 and a gear pump 16 located below the kneading machine 11.

The effluent stream 13 of the paste of the functionalized elastomer is transferred to a granulator 17, preferably under water, for cutting it therein by means of a gear pump 16 connected to the granulator.

In accordance with an embodiment of the polymerization process illustrated in FIG. 1, the kneading machine 11 is intended solely for functionalization.

In accordance with alternative forms of installation of other forms of implementation of the method, not illustrated in FIG. 1, the kneading machine 11 can be equipped with a condensation circuit, which allows condensing the gases generated in the reactor 11 by means of a condenser and returning all or part of the condensate to the polymerization reactor 1.

In accordance with one embodiment of these alternative forms, which are not illustrated, the condensing circuit may preferably be connected to a device that allows the removal of non-condensable products in a manner that is known per se.

According to the embodiment of the invention illustrated in FIG. 1, a polymerization inhibitor and an antioxidant are sequentially introduced into the paste stream 13 of the functionalized elastomer discharged from the kneading machine 11, respectively, by sources 14 and 15 of the feed above the gear pump 16.

The installation illustrated in FIG. 1 further comprises a cutting device 17, for example a granulator, preferably an underwater granulator. The cutting device 17 is equipped with an inlet connected to a gear pump 16, through which the unloading device feeds the elastomer paste for cutting into the device 17. The device 17 is also equipped with an outlet adapted for continuous discharge from the specified device 17 of the paste particles of the functionalized elastomer in the form of a stream 18, in particular, to a device designed to remove solvent and isoprene.

A. MEASUREMENT METHODS

I. Determination of the microstructure of the obtained polyisoprenes

Used the method of "near infrared" (NIR) analysis. It is an indirect method in which "control" elastomers are used, the microstructure of which was measured by ¹³ C nuclear magnetic resonance (NMR). Use the quantitative ratio (Bouguer-Lambert-Beer law) existing between the distribution of the monomer in the elastomer and the shape of its NMR spectrum. This method is used in two stages:

1) Calibration:

- Remove the corresponding spectra of "control" elastomers.

- Establish a mathematical model that connects the microstructure with this spectrum, by the method of regression analysis of partial least squares (PLS, Partial Least Squares), based on factor analysis of spectral data. The two documents below describe in detail the theory and practical implementation of the method of "multi-parameter" data analysis:

(1) P. Geladi and B.R. Kowalski "Partial Least Squares regression: a tutorial" Analytica Chimica Acta, Vol. 185, 1-17 (1986).

PLS -

et pratique" [PLS Regression - Theory and Practice] Paris, Editions Technip (1998).(2) M. Tenenhaus "La

Pls -

et pratique "[PLS Regression - Theory and Practice] Paris, Editions Technip (1998).

2) Measurement:

- Record the spectrum of the sample.

- Calculate the microstructure.

II. Determining the amount of GMDE grafted on the resulting polyisoprenes

a) Principle:

This determination is carried out using NMR analysis on coagulated samples.

The spectra were recorded on a Bruker Avance 500 MHz spectrometer equipped with a 5 mm broadband in-band Z-gradient transducer (BBI).

In a ¹ H NMR quantitative experiment, a simple 30 ° pulse sequence and a 5 second period between each acquisition (1024 counts) were used.

b) Sample preparation:

Samples, approximately 25 mg, are dissolved in carbon disulfide (CS ₂ ), approximately 1 ml.

To close the signal add 100 μl of deuterated cyclohexane (C ₆ D ₁₂ ).

c) Characterization:

The ¹ H NMR spectrum makes it possible to quantify IR ethylene units by integrating wide unresolved spectral bands of signals characteristic of the following protons:

PI 1-4: ¹ H δ ethylene mn ^{-1 1} H broad unresolved band between 5.40 million and 4.75 million ^{-1 -1}

PI 3-4: ² H ^-1 million ethylene δ ¹ H broad unresolved band between 4.75 million and 4.30 million ^{-1 -1}

Chemical shifts are calibrated with respect to the impurity protonated CS ₂ mn ^-1 δ ¹ H ^-1 at 7.18 million, being compared with the standard TMS (δ mn ^{-1 1} H at 0 mn ^-1).

The ¹ H NMR spectrum makes it possible to quantify GMDE units by integrating wide unresolved spectral bands of signals characteristic of the following protons:

CH ₂ -O-Si-: δ mn ^{-1 1} H broad unresolved band at 3.6 million ^-1

-CH ₂ -O- + -CH-O-: δ mn ^{-1 1} H broad unresolved band at 3.25 million ^-1

-CH ₂ -O-: δ ppm ^{-1 1} H wide unresolved band at 3.00 ppm ^-1

CH ₃ -Si-: δ mn ^{-1 1} H broad unresolved band at -0.02 million ^-1

CH ₂ -Si-: δ mn ^{-1 1} H broad unresolved band at 0.46 million ^-1

Chemical shifts are calibrated with respect to the impurity protonated CS ₂ mn ^-1 δ ¹ H ^-1 at 7.18 million, being compared with the standard TMS (tetramethylsilane) (mn ^-1 δ ¹ H at 0 mn ^-1).

The corrected correlation spectrum of 2D ¹ H / ¹³ C ¹ J HSQC (heteronuclear single-quantum correlation) NMR allows one to confirm the nature of the grafted unit through chemical shifts of carbon atoms and protons.

III - Determination of the molecular weight distribution of the obtained polyisoprenes by size exclusion chromatography (SEC)

a) Measurement principle:

Size exclusion chromatography or SEC allows the separation of macromolecules in solution according to their size by means of columns filled with porous gel. Macromolecules are separated in accordance with their hydrodynamic volume, with the most voluminous eluting first.

Not being an absolute method, SEC makes it possible to understand the distribution of molecular masses of the polymer. Based on commercially available standards, various number average molecular weights (Mn) and weight average molecular weights (Mw) can be determined and the polydispersity index (PI = Mw / Mn) calculated by Moore calibration.

b) Preparation of polymer:

Special processing of the polymer sample before analysis is not required. It is simply dissolved in tetrahydrofuran with a concentration of approximately 1 g / l.

c) SEC analysis:

Option c1) The apparatus used is a Waters Alliance chromatographic line. The elution solvent is tetrahydrofuran, the flow rate is 1 ml / min, the system temperature is 35 ° C, and the analysis time is 30 minutes. Use a set of two columns Waters, under the trade name Styragel HT6E.

The volume of polymer sample introduced into the column of the solution is 100 μl. The detector is a Waters 2140 differential refractometer, and the chromatographic data processing program is a Waters Millennium system.

Option c2) The apparatus used is a Waters Alliance chromatograph. The elution solvent is tetrahydrofuran, the flow rate is 0.7 ml / min, the system temperature is 35 ° C, and the analysis time is 90 minutes. A set of four Waters columns connected in series with the trade names Styragel HMW7, Styragel HMW6E and two Styragel HT6E are used.

The volume of polymer sample introduced into the column of the solution is 100 μl. The detector is a Waters RI32X differential refractometer, and the chromatographic data processing program is a Waters Millennium system.

B - TESTS

Methods for the synthesis of functionalized polyisoprene by coordination catalysis in a highly concentrated mixture according to one alternative form of the invention

A few definitions:

Nd = Neodymium

Bd = butadiene

Isop = Isoprene

MCH = methylcyclohexane

DiBAH = diisobutylaluminum hydride

TOA = trioctylaluminum

DEAC = diethylaluminium chloride

TiBA = triisobutylaluminum

GMDE = (3-glycidyloxypropyl) methyldiethoxysilane

I - Synthesis of catalytic systems

1 - Nd / Bd / DiBAH / DEAC

The Nd / Bd / DiBAH / DEAC catalyst system diluted in the MCH is synthesized in accordance with the procedure described in WO-A-02/38636 on behalf of the applicant companies:

To obtain this catalyst, a neodymium phosphate salt in powder form, previously purified from impurities, is introduced into the reactor. This salt is then purged with nitrogen for 10 minutes to make the reaction mixture inert. Then carry out the following sequential stages:

- The first stage of solvation:

A solvent consisting of pre-distilled MCH, purified over alumina and sparged with nitrogen is introduced into the reactor. For gel formation, the duration and temperature of the operation during which the solvent and neodymium salt are brought into contact are 30 minutes at 30 ° C with stirring.

- The second stage of adding monomer:

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

- Third alkylation step:

Then, DiBAH is introduced into the reactor in solution in MCH as an alkylating agent for the neodymium salt, in accordance with a concentration of about 1 mol / L. The duration of the alkylation is 15 minutes The temperature of the alkylation reaction is 30 ° C.

- The fourth stage of halogenation:

Then, DEAC is introduced into the reactor in solution in MCH as a halogen atom donor, in accordance with a concentration of approximately 0.5 mol / L. The temperature of the reaction mixture was adjusted to 60 ° C.

- Fifth stage of aging:

The mixture obtained in this way is maintained at a temperature of 60 ° C for 50 minutes.

Finally, the resulting catalytic solution is stored in a nitrogen atmosphere at a temperature of from -15 to -5 ° C.

The catalytic system is characterized by its catalytic formula, which is given as Nd / monomer / alkylating agent / halogenating agent in molar ratios indexed to the neodymium salt. In the examples, the concentration of neodymium is 0.02 mol / L.

2 - Nd / Isop / TOA / DEAC

The Nd / Isop / TOA / DEAC catalyst system was diluted in n-pentane.

To obtain this catalyst, a neodymium phosphate salt in powder form, previously purified from impurities, is introduced into the reactor. This salt is then purged with nitrogen for 10 minutes to make the reaction mixture inert. Then perform the following sequential stages:

- The first stage of solvation:

A solvent consisting of n-pentane, previously purified over alumina and sparged with nitrogen, is introduced into the reactor. For gel formation, the duration and temperature of the operation, in which this solvent and neodymium salt are brought into contact, is 30 minutes at 30 ° C with stirring.

- The second stage of adding monomer:

Then, isoprene, previously purified over alumina and sparged with nitrogen, is introduced into the reactor at 30 ° C. This monomer will be used to preform the catalyst during the aging step.

- Third alkylation step:

Then, TOA in solution in n-pentane is introduced into the reactor as an alkylating agent for the neodymium salt, in accordance with a concentration of about 1 mol / L. The duration of the alkylation is 15 minutes The temperature of the alkylation reaction is 30 ° C.

- The fourth stage of halogenation:

Then, DEAC is introduced into the reactor in solution in n-pentane as a halogen atom donor, in accordance with a concentration of approximately 0.5 mol / L. The temperature of the reaction mixture was adjusted to 60 ° C.

- Fifth stage of aging:

The mixture obtained in this way is maintained at a temperature of 60 ° C for 50 minutes.

Finally, the resulting catalytic solution is stored in a nitrogen atmosphere at a temperature of from -15 to -5 ° C.

The catalytic system is characterized by its catalytic formula, which is given as Nd / monomer / alkylating agent / halogenating agent in molar ratios indexed to the neodymium salt. In the examples, the concentration of neodymium is 0.02 mol / L.

II - Procedure for continuous polymerizations

Example 1

Continuous polymerization is carried out on a line containing a gas phase reactor, which contains two Z-shaped blades, has a total volume of 150 liters and is equipped with a discharge device with an unloading screw and a gear pump, and a self-cleaning kneading machine, which itself is also equipped with a discharge device with a discharge screw and gear pump. This continuous line corresponds to the installation shown in FIG. one.

Isoprene and pentane are mixed in a dynamic stirrer 4 located for this purpose above the polymerization reactor 1. The resulting mixture is introduced in the form of an inlet stream 3 directly into the reactor 1.

Isoprene is introduced at a flow rate of 7.8 kg / h in accordance with stream 5 into the mixer 4.

Pentane is introduced at a flow rate of 12.54 kg / h in accordance with stream 6 into mixer 4, i.e. approximately 37 wt.% monomer in the reaction mixture.

The coordination catalysis system is also introduced directly into the reactor 1 in accordance with stream 2. This system was obtained by following the preparation method described in the previous section I, part 2.

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

Nd / Isop / TOA / DEAC = 1/30/8 / 2.8

The amount of neodymium is 150 μmol per 100 g of polymerizable isoprene. The molar concentration of neodymium in the catalyst is 0.02 mol / L.

TiBA is also introduced directly into the reactor 1 in accordance with a separate and independent stream 7 as an additional aluminum alkyl compound. The amount of TiBA introduced 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 so that it is 0.5 bar (g), and the vapor is condensed in an external condenser 8 and returned to the polymerization reactor 1 containing two Z-shaped blades.

The temperature of the reactor shell is maintained at 60 ° C.

The average residence time t _{0 of the} reaction is 80 minutes.

The unloading auger allows you to transfer the product from the reactor 1 to the gear pump 10.

The phenomenon of expansion is not observed.

The conversion measured on the extracted sample at the boundary of the first third of the reactor volume is 91%. The conversion measurement was based on a GC measurement of isoprene in the recovered sample. Residual isoprene in the recovered sample was quantified as 3.4 wt.%.

The streams are characterized by the distribution of the residence time shown in FIG. 2.

de la

chimique: conception et fonctionnement des

Editors. 1993, TEC & DOC - LAVOISIER, стр. 170 to 172. Экспериментальные точки получены из образцов, извлеченных из потока 9, как показано на Фиг. 1, на выходе реактора 1 на конце разгрузочного шнека.The experimental points allowing to establish this distribution of the residence time were obtained by measuring by gas chromatography the changes in the concentration of the indicator after a very rapid injection of the sample in accordance with the pulsed method of introducing a chemically inert product according to the principle described in the book by Jacques Villermaux,

de la

chimique: conception et fonctionnement des

Editors. 1993, TEC & DOC - LAVOISIER, pp. 170 to 172. Experimental points were obtained from samples recovered from stream 9, as shown in FIG. 1, at the outlet of the reactor 1 at the end of the discharge screw.

Modeling these experimental points using gamma distribution allows you to determine the variance of the function E of the distribution of residence time.

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

where Γ (k) is the gamma function k;

k is 1.22;

t ₀ is the average residence time, i.e. 80 minutes

t is the time of stay.

The variance of this residence time distribution function is

The standard deviation of the residence time distribution function is derived from this variance, where the standard deviation is 88.4, which is greater than the result of dividing the average residence time by 2√3, i.e.

The unloading auger allows you to transfer the product from the reactor 1 to the gear pump 10.

The gear pump 10 transfers the paste of the pseudo-living elastomer into a self-cleaning gas mixing kneading machine 11. The flow rate of the stream carried by the gear pump 10 is equal to the sum of the flow rates of the flows introduced into the reactor 1.

A self-cleaning kneading machine is a kneading reactor machine containing two blades having a total volume of 39 liters, with an unloading device consisting of two discharge augers and a gear pump 16. The flow in this kneading reactor containing two blades can be comparable to the flow of cork-like flow.

The temperature of the reactor shell is maintained at 68 ° C.

The average residence time t _{0 of the} reaction of the functionalizing agent with the solution of the pseudo-living polymer in the self-cleaning kneading machine 11 is 37 minutes.

GMDE is introduced at a flow rate of 0.456 l / h into a self-cleaning kneading machine, at the same level as the solution entering the kneading machine. The GMDE solution has a concentration of 0.47 mol / L.

The used polymerization inhibitor stream 14 and antioxidant stream 15 are acetylacetone with a flow rate of 0.224 l / h at a concentration of 120 g / l and N- (1,3-dimethylbutyl) -N'-phenyl-para-phenylenediamine in accordance with 0.5 ppm (ppm: parts by weight per 100 parts by weight of monomer - isoprene). Data polymerization inhibitor and antioxidant is introduced above the gear pump 16.

The gear pump 16 transfers the elastomer paste to the underwater granulator 17. The flow rate when transferred by the gear pump 16 is equal to the sum of the flow rates of the streams entering the reactor 1, to which the flow rates of the functionalizing agent 12, the polymerization inhibitor 14 and the antioxidant 15 are added.

The resulting degree of functionalization is 70%.

Example 2

Continuous polymerization is carried out on a line containing a gas phase reactor, which contains two Z-shaped blades, has a total volume of 150 liters and is equipped with a discharge device with an unloading screw and a gear pump, and a self-cleaning kneading machine, which itself is also equipped with a discharge device with a discharge screw and gear pump. This continuous line corresponds to the installation shown in FIG. one.

Isoprene and pentane are mixed in a dynamic stirrer 4 located for this purpose above the polymerization reactor 1. The resulting mixture is introduced in the form of an inlet stream 3 directly into the reactor 1.

Isoprene is introduced at a flow rate of 7.52 kg / h in accordance with stream 5 into the mixer 4.

Pentane is introduced at a flow rate of 12.01 kg / h in accordance with stream 6 into mixer 4, i.e. approximately 37 wt.% monomer in the reaction mixture.

The coordination catalysis system is also introduced directly into reactor 1 in accordance with stream 2. The catalyst system is based on tris [bis (2-ethylhexyl) phosphate] neodymium, isoprene as a pre-prepared monomer, TOA as an alkylating agent, and on DEAC as an atom donor halogen. It was obtained following the preparation method described in the previous section, part 2.

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

Nd / Isop / TOA / DEAC = 1/30/8 / 2.8

The amount of neodymium is 170 μmol per 100 g of polymerizable isoprene. The molar concentration of neodymium in the catalyst is 0.02 mol / L.

TiBA is also directly introduced into the reactor 1 in accordance with a separate and independent stream 7 as an additional alkyl aluminum compound. The amount of TiBA introduced is 2200 μmol / 100 g of polymerizable isoprene. The molar concentration of the TiBA solution is 0.294 mol / L.

The pressure of the gas phase is regulated so that it is 0.16 bar (g), and the vapor is condensed in an external condenser 8 and returned to the polymerization reactor 1 containing two Z-shaped blades.

The temperature of the reactor shell is maintained at 21 ° C.

The average residence time t _{0 of the} reaction is 80 minutes.

The discharge screw allows you to transfer the product from the reactor 1 to the gear pump 10.

The phenomenon of expansion was not observed.

The conversion measured on the extracted sample at the boundary of the first third of the reactor volume is 92%. The conversion measurement was based on the GC measurement of isoprene in the recovered sample. Residual isoprene in the recovered sample was quantified as 2.9 wt.%.

The streams are characterized by the distribution of the residence time shown in FIG. 2.

de la

chimique: conception et fonctionnement des

Editors. 1993, TEC & DOC - LAVOISIER, стр. 170 to 172. Экспериментальные точки получены из образцов, извлеченных из потока 9, показанного на Фиг. 1, на выходе реактора 1 на конце разгрузочного шнека.The experimental points allowing to establish this distribution of the residence time were obtained by measuring by gas chromatography the changes in the concentration of the indicator after a very rapid injection of the sample in accordance with the pulsed method of introducing a chemically inert product according to the principle described in the book by Jacques Villermaux,

de la

chimique: conception et fonctionnement des

Editors. 1993, TEC & DOC - LAVOISIER, pp. 170 to 172. Experimental points were obtained from samples extracted from stream 9 shown in FIG. 1, at the outlet of the reactor 1 at the end of the discharge screw.

Modeling these experimental points using gamma distribution makes it possible to determine the variance of the residence time distribution function E.

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

where Γ (k) is the gamma function k;

k is 1.22;

t ₀ is the average residence time, i.e. 80 minutes

t is the time of stay.

The variance of this residence time distribution function is

The standard deviation of the residence time distribution function is derived from this variance, where the standard deviation is 88.4, which is greater than the result of dividing the average residence time by 2√3, i.e.

The unloading auger makes it possible to transfer the product from the reactor 1 to the gear pump 10.

The gear pump 10 transfers the paste of the pseudo-living elastomer into a self-cleaning gas mixing kneading machine 11. The flow rate of the stream carried by the gear pump 10 is equal to the sum of the flow rates of the flows introduced into the reactor 1.

A self-cleaning kneading machine is a kneading reactor machine containing two blades, having a total volume of 39 liters, with an unloading device consisting of two discharge augers and a gear pump 16. The flow in this kneading reactor containing two blades is comparable to the flow of a cork-like flow.

The temperature of the reactor shell is maintained at 68 ° C.

The average residence time t _{0 of the} reaction of the functionalizing agent with the solution of the pseudo-living polymer in the self-cleaning kneading machine 11 is 37 minutes.

GMDE is introduced at a flow rate of 0.824 l / h into a self-cleaning mixing machine at the same level as the solution entering the mixing machine. The GMDE solution has a concentration of 0.45 mol / L.

The polymerization inhibitor stream 14 used and the antioxidant stream 15 are acetylacetone with a flow rate of 0.387 l / h at a concentration of 120 g / l and N- (1,3-dimethylbutyl) -N'-phenyl-para-phenylenediamine in accordance with 0.5 ppm (ppm: parts by weight per 100 parts by weight of monomer - isoprene). Data polymerization inhibitor and antioxidant is introduced above the gear pump 16.

The gear pump 16 transfers the elastomer paste to the underwater granulator 17. The flow rate when transferred by the gear pump 16 is equal to the sum of the flow rates of the streams entering the reactor 1, to which the flow rates of the functionalizing agent 12, the polymerization inhibitor 14 and the antioxidant 15 are added.

The resulting degree of functionalization is 100%.

Example 3

Continuous polymerization is carried out on a line containing a gas phase reactor, which contains two Z-shaped blades, has a total volume of 150 liters and is equipped with a discharge device with an unloading screw and a gear pump, and a self-cleaning kneading machine, which itself is also equipped with a discharge device with a discharge screw and gear pump. This continuous line corresponds to the installation shown in FIG. one.

Isoprene and pentane are mixed in a dynamic stirrer 4 located for this purpose above the polymerization reactor 1. The resulting mixture is introduced in the form of an inlet stream 3 directly into the reactor 1.

Isoprene is introduced at a flow rate of 7.52 kg / h in accordance with stream 5 into the mixer 4.

Pentane is introduced at a flow rate of 12.26 kg / h in accordance with stream 6 into mixer 4, i.e. approximately 37 wt.% monomer in the reaction mixture.

The coordination catalysis system is also introduced directly into reactor 1 according to stream 2. The catalyst system is based on tris [bis (2-ethylhexyl) phosphate] neodymium, butadiene as a pre-prepared monomer, DiBAH as an alkylating agent and DEAC as a halogen atom donor . It was obtained following the preparation method described in the previous section, part 1.

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

Nd / Bd / DiBAH / DEAC = 1/30 / 1.8 / 2.6

The amount of neodymium is 170 μmol per 100 g of polymerizable isoprene. The molar concentration of neodymium in the catalyst is 0.02 mol / L.

An additional alkylaluminum compound is not added.

The pressure of the gas phase is regulated so that it is 0.16 bar (g), and the vapor is condensed in an external condenser 8 and returned to the polymerization reactor 1 containing two Z-shaped blades.

The temperature of the reactor shell is maintained at 35 ° C.

The average residence time t _{0 of the} reaction is 80 minutes.

The unloading auger allows you to transfer the product from the reactor 1 to the gear pump 10.

The phenomenon of expansion was not observed.

The conversion measured on the extracted sample at the boundary of the first third of the reactor volume is 91%. The conversion measurement was based on the GC measurement of isoprene in the recovered sample. Residual isoprene in the recovered sample was quantified as 3.4 wt.%.

The streams are characterized by the distribution of the residence time shown in FIG. 2.

de la

chimique: conception et fonctionnement des

Editors. 1993, TEC & DOC - LAVOISIER, стр. 170 to 172. Экспериментальные точки получены из образцов, извлеченных из потока 9, показанного на Фиг. 1, на выходе реактора 1 на конце разгрузочного шнека.The experimental points allowing to establish this distribution of the residence time were obtained by measuring by gas chromatography the changes in the concentration of the indicator after a very rapid injection of the sample in accordance with the pulsed method of introducing a chemically inert product according to the principle described in the book by Jacques Villermaux,

de la

chimique: conception et fonctionnement des

Editors. 1993, TEC & DOC - LAVOISIER, pp. 170 to 172. Experimental points were obtained from samples extracted from stream 9 shown in FIG. 1, at the outlet of the reactor 1 at the end of the discharge screw.

Modeling these experimental points using gamma distribution makes it possible to determine the variance of the residence time distribution function E.

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

where Γ (k) is the gamma function k;

k is 1.22;

t ₀ is the average residence time, i.e. 80 minutes

t is the time of stay.

The variance of this residence time distribution function is

The standard deviation of the residence time distribution function is derived from this variance, where this standard deviation is 88.4, which is greater than the result of dividing the average residence time by 2√3, i.e.

The unloading auger allows you to transfer the product from the reactor 1 to the gear pump 10.

The gear pump 10 transfers the paste of the pseudo-living elastomer into a self-cleaning gas mixing kneading machine 11. The flow rate of the stream carried by the gear pump 10 is equal to the sum of the flow rates of the streams entering the reactor 1.

A self-cleaning kneading machine is a kneading reactor machine containing two blades, having a total volume of 39 liters, with an unloading device consisting of two discharge augers and a gear pump 16. The flow in this kneading reactor containing two blades is comparable to the flow of a cork-like flow.

The temperature of the reactor shell is maintained at 68 ° C.

The average residence time t _{0 of the} reaction of the functionalization agent with the pseudo-living polymer solution in the self-cleaning kneading machine 11 is 37 minutes.

GMDE is introduced at a flow rate of 0.172 l / h into a self-cleaning kneading machine at the same level as the solution entering the kneading machine. The GMDE solution has a concentration of 0.45 mol / L.

The polymerization inhibitor stream 14 and the antioxidant stream 15 used are acetylacetone with a flow rate of 0.321 l / h at a concentration of 26 g / l and N- (1,3-dimethylbutyl) -N'-phenyl-para-phenylenediamine in accordance with 0.5 ppm (ppm: parts by weight per 100 parts by weight of monomer - isoprene). Data polymerization inhibitor and antioxidant is introduced above the gear pump 16.

The gear pump 16 transfers the elastomer paste to the underwater granulator 17. The flow rate when transferred by the gear pump 16 is equal to the sum of the flow rates of the streams entering the reactor 1, to which the flow rates of the functionalizing agent 12, the polymerization inhibitor 14 and the antioxidant 15 are added.

The resulting degree of functionalization is 75%.

The control

Non-functionalized polyisoprene was synthesized in accordance with the method described in example 1 using a catalytic system characterized by the following molar ratios with respect to neodymium: Nd / Isop / TOA / DEAC = 1/30/8 / 2.8, except for the difference that the functionalizing agent was not introduced into the kneading machine 11.

The amount of neodymium is 100 μmol per 100 g of polymerizable isoprene. The molar concentration of neodymium in the catalyst is 0.02 mol / L.

TiBA is also introduced directly into the reactor 1 in accordance with a separate and independent stream 7 as an additional aluminum alkyl compound. The amount of TiBA introduced 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 the sample recovered from stream 9 above the gear pump 10 is 99% with a total reaction time of 80 minutes. The conversion measurement was established based on the GC measurement of isoprene in the recovered sample.

Polymerization tests carried out with two types of catalyst system and the corresponding functionalized polyisoprenes are presented in tables 1 and 2.

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

(CH ₂ -Si / PI) * Mn * 1.10 ^-4 , where CH ₂ -Si / PI is measured in meq / kg and Mn in g mol ^-1 .

This continuous method for the synthesis of polyisoprene in accordance with the invention in a highly concentrated mixture allows to achieve a high degree of conversion of 99%, including at least 91% within the first third of the reaction volume of the polymerization reactor 1. In addition, the standard deviation of the distribution function of the residence time in the polymerization reactor more than the result of dividing the average residence time by 2√3. The average degree of functionalization (or the average percentage of functionalized chains) is even higher and varies from 70 to 100% of functionalized chains. This method has absolute flexibility and is suitable for cost-effective industrial production as a result of a reduced amount of solvent used, while providing increased productivity with a high degree of conversion.

Evaluation of the resulting polyisoprenes in the rubber composition

1 - Production of rubber compositions

All necessary basic components (diene elastomer, reinforcing fillers and a bonding agent, plasticizers, other additives), with the exception of the crosslinking system, are sequentially introduced into a standard closed rubber mixer. Then, thermomechanical treatment (non-productive phase) is carried out in one stage, which lasts a total of approximately 3 to 4 minutes, until a maximum temperature “fall” of 165 ° C is reached. The mixture thus obtained is recovered and cooled.

After cooling the mixture thus obtained, a crosslinking system consisting of sulfur and sulfonamide (CBS) is introduced into the external mixer (homogenizer for final mixing), maintained at a low temperature. Then, the combined materials are mixed (production phase) for several minutes (approximately ten minutes).

Subsequently, the composition thus obtained is passed through calendars to form a sheet or plate for evaluation in a laboratory.

2 - Measurements and tests

The rubber compositions are evaluated after vulcanization as described below.

Dynamic properties are measured on a viscosity analyzer (Metravib VA4000) in accordance with ASTM D 5992-96. Record the response of the sample vulcanized composition (cylindrical test specimen 4 mm in thickness and 400 mm ² in cross-section) subjected to the sinusoidal load at a simple alternating shear stress with a frequency of 10 Hz under conditions of temperature sweep, under steady voltage of 0.7 MPa: registering the tan loss angle tg (δ) observed at -10 ° C (i.e. tg (δ) _{-10 ° C} ). The deformation amplitude is also scanned at the same sample at a temperature of 40 or 60 ° C from 0.1 to 50% (forward stroke), and then from 50 to 1% (reverse stroke): the maximum value of the loss tangent is recorded for the reverse stroke, denoted by tg (δ) _max . The nonlinearity, denoted as ΔG *, is the difference in shear modulus between the deformation of 0.1% and 50% in MPa.

It should be remembered that, as is well known to specialists in this field of technology, the value of tg (δ) _max (in accordance with the sweep of the deformation amplitude at a given temperature) is representative of hysteresis and rolling resistance (the smaller tg (δ) _max , the lower the hysteresis and, therefore, rolling resistance), while the tan (δ) _{-10 ° C} value (in accordance with the temperature sweep for a given deformation) is representative of the wet grip potential of the tire (the higher tg (δ) _{-10 ° C} the better grip).

3 - Results

Compositions and their properties are shown in tables 3 and 4 below.

The properties of the compositions in the vulcanized state show that the compositions in accordance with the invention (compositions A and B) have hysteresis properties, as well as strain hardening and tensile strength properties, significantly improved compared to the properties of the control composition, which uses unfunctionalized IR (composition C ), which is very favorable for obtaining tires with reduced rolling resistance when using the composition in accordance with the invention or as a surface ty of the tire rolling, either as a base layer of the tire rolling surface, or also as rubber for the side wall.

When applying the composition in accordance with the invention as the rolling surface of the tire, in addition, the adhesion quality of the tire to wet road surfaces is maintained (similar values of tg (δ) _{-10 ° C} ).

ANNEX 1

The intrinsic viscosity is determined by measuring the flow time (t) of the polymer solution and the flow time of toluene (t ₀ ) in the capillary tube. The toluene flow rate and the flow rate of 0.1 g / dl of the polymer solution (C) are measured in a Ubbelode tube (0.46 mm capillary diameter, 18 to 22 ml capacity), placed in a thermostatically controlled bath at 25 ± 0.1 ° C.

The intrinsic viscosity is obtained using the following relationship:

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

t is the flow rate of the polymer solution in toluene in seconds;

t ₀ - toluene flow time in seconds;

η _inh is the intrinsic viscosity, expressed in dl / g.

Claims (51)

1. The method of continuous synthesis of diene elastomer, characterized in that it includes the following simultaneous stages: - related to polymerization: a) continuous introduction into the polymerization reactor having a gas phase and equipped with at least one mixing rotor and a discharge device, at least: i. one coordination catalysis system, ii. at least one conjugated diene monomer for polymerization, and iii. from 0 to 70 wt.% organic solvent based on the total weight of the monomer (s) and solvent; b) continuous polymerization of the monomer (s) using the means necessary to achieve a degree of conversion of at least 60% within the first third of the reaction volume of the polymerization reactor; c) stirring the polymerization mixture by continuously moving at least one stirring rotor about an axis of rotation; d) continuous unloading of a paste of a pseudo-living elastomer obtained by polymerization; where the standard deviation of the distribution function of the residence time in the polymerization reactor is greater than the result of dividing the average residence time by 2√3, - related to functionalization: e) continuously transferring this paste to a kneading machine having a gas phase, a mixing device comprising at least one mixing rotor, and an unloading device; f) continuously introducing into the kneader a functionalizing agent corresponding to formula AR ₁ -B, wherein A represents a group capable of reacting with the reactive end psevdozhivuschego elastomer, R ₁ represents an atom or group of atoms forming the bond between A and B, and B is a functional a group capable of interacting with a reinforcing filler; g) continuous functionalization of the pseudo-living elastomer by reaction with a functionalizing agent in said kneading machine; h) continuous unloading of paste of functionalized elastomer obtained in the previous step; i) isolation of a functionalized diene elastomer. 2. A method for the continuous synthesis of a diene elastomer according to claim 1, characterized in that the degree of conversion is at least 80% within the first third of the reaction volume of the polymerization reactor. 3. The method of continuous synthesis of a diene elastomer according to claim 1 or 2, characterized in that the standard deviation of the distribution function of the residence time in the polymerization reactor is greater than the result of dividing the average residence time by 2. 4. The method according to p. 1 or 2, characterized in that the mixing of the polymerization mixture is carried out by continuous movement of two mixing rotors. 5. The method according to p. 4, characterized in that the mixing rotors are blades of a sigmoid or Z-shaped type. 6. The method according to p. 1 or 2, characterized in that at stage h) the unloaded elastomer paste is transferred to a granulator designed to cut the specified elastomer paste. 7. The method according to p. 6, characterized in that the granulator is an underwater granulator. 8. The method according to p. 1 or 2, characterized in that the mixing device of the kneading machine captures at least 90% of the volume of the kneading machine, preferably 95%, which ensures self-cleaning. 9. The method according to p. 1 or 2, characterized in that the unloading of the elastomer paste in stage d) and, if necessary, in stage h) is carried out by the combined action of at least one discharge screw and gear pump constituting the unloading device. 10. The method according to p. 1 or 2, characterized in that the group R ₁ represents a linear, branched or cyclic divalent hydrocarbon radical and may contain one or more aromatic radicals and / or one or more than one heteroatom, preferably saturated or unsaturated and a cyclic or non-cyclic divalent C ₁ -C ₁₈ aliphatic hydrocarbon radical, which may contain one or more aromatic radicals. 11. The method according to p. 1 or 2, characterized in that group A, capable of interacting with the reactive end of the pseudo-living elastomer, is selected from epoxides, glycidyloxy, carbonyls, aldehydes, ketones, esters, carbonates, anhydrides, isocyanates, imines, alkoxysilanes , nitriles, aziridines, acid chlorides, azines, cyclic halogenosilanes, oximes, ureas, methacrylates, hydrazones, lactones, thiolactones, thiocarboxylic acid esters, nitroso or carbamates. 12. The method according to p. 1 or 2, characterized in that the functional group capable of interacting with a reinforcing filler is a functional group containing one or more functional groups selected from a protected or unprotected primary amine, a protected or unprotected secondary amine, tertiary amine, imine, imide, amide, nitrile, azo, carbamate, methacrylate, methacrylamide, hydroxyl, carbonyl, carboxyl, epoxy, glycidyloxy, thiol, sulfide, disulfide, thiocarbonyl, thioester, s lfonila, silane, silanol, alkoxysilane, dialkoxysilanes, trialkoxysilanes stannyl, a tin halide, tin halide, tin aryl halide, a polyether-based nitrogen heterocycle, heterocycle oxygen-based, sulfur-based heterocycle and an aromatic group substituted by the above groups. 13. The method according to p. 1 or 2, characterized in that the catalytic system is based at least on: (i) one organic rare earth metal salt, (ii) one alkylating agent and, if necessary, (iii) a single halogen atom donor and / or (iv) one pre-prepared diene monomer. 14. The method according to p. 1 or 2, characterized in that during stage a) into the polymerization reactor by means of a stream different from the stream of the catalytic system, at least one alkyl aluminum compound of the formula AlR ₃ or HAlR ₂ is continuously introduced, where R is an alkyl radical and H represents a hydrogen atom, identical or non-identical to the compound of said catalyst system. 15. The method according to p. 14, characterized in that before stage a) the alkyl aluminum compound, the solvent and the monomer for polymerization are brought into contact to form a mixture, which is introduced into the polymerization reactor during stage a). 16. The method according to p. 1 or 2, characterized in that the diene monomer for polymerization is selected from butadiene, isoprene or a mixture thereof. 17. Installation for implementing the method according to any one of paragraphs. 1-16, characterized in that it contains: a polymerization reactor (1) having a gas phase and equipped with at least one mixing rotor and a discharge device, where the reactor (1) is provided with at least: - several inlets, suitably connected to several supply sources, including at least one source (2) of supply of the catalytic system, one source (5) of supply of at least one monomer and, if necessary, one source (6) for supplying an inert hydrocarbon solvent, and - an outlet adapted for continuous unloading from said reactor (1) a paste of a pseudo-living elastomer in the form of an outlet stream, connected through a discharge device to a kneading machine (11) of a self-cleaning type, - a mixing rotor suitable for a high viscosity reaction mixture, - an unloading device consisting of at least one unloading auger; kneading machine (11), preferably a self-cleaning type, capturing at least 90% of the volume of the kneading machine, as a functionalization reactor, provided at least: - an inlet connected to the source (9) of the paste of the pseudo-living elastomer discharged from the polymerization reactor (1). - an inlet connected to a source (12) of supply of the functionalizing agent, and - an outlet adapted for the continuous unloading from said kneading machine (11) of a paste of functionalized elastomer in the form of an outlet stream (13) into a device (17) intended for cutting the elastomer paste. 18. Installation according to claim 17, characterized in that the polymerization reactor (1) is a reactor containing two sigmoid or Z-shaped blades. 19. Installation according to claim 17 or 18, characterized in that the device (17), designed to cut the paste functionalized elastomer, unloaded from the kneading machine (11), is a granulator. 20. Installation according to claim 17 or 18, characterized in that the discharge device of the polymerization reactor (1) and / or kneading machine (11) consists of at least one discharge screw, the end of which is connected to a gear pump (10) and / or (16). 21. Installation according to claim 17 or 18, characterized in that it contains a source of alkyl aluminum supply (7) directly connected to the polymerization reactor (1) or connected to a mixture of streams (6) and (5) above the polymerization reactor, provided that the feed of the catalytic system (2) is carried out independently of this mixture of flows. 22. Installation according to claim 17 or 18, characterized in that at least one of the reactor (1) and kneading machine (11) is provided with a second outlet in the capacitor. 23. Installation according to claim 22, characterized in that at least one of the capacitors is provided with an outlet for returning the condensate back to the reactor (1).

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