CONTINUOUS SYNTHESIS METHOD FOR A MODIFIED DIENE ELASTOMER, FACILITY FOR IMPLENTING SAME

摘要

A continuous method for synthesizing a diene includes modifying the diene elastomer in a functionalizing device by:
a kinetic model according to which the ratio of the rate constants is greater than 1, anda flow represented by a residence time distribution in the functionalizing device that is expressed according to equations 1 or 3:
(i) in a functionalizing device having at least one tubular continuous reactor or having at least one cascade of at least two stirred reactors,;E1(t)=12(Pπθ1t)12-P(θ1-t)24θ1tEq1(ii) in a functionalizing device that is a combination of the device (i) and of a device having at least one continuous stirred reactor, having a residence time distribution characterized by the following equation:;E2(t)=(-tθ2)θ2Eq2the device (ii) having a residence time distribution characterized by the equation 3 below, which is the result of the convolution of equations 1 and 2:;E12(t)=∫0tE1(t-T)E2(T)TE12(t)=∫0t12(Pπθ1(t-T))12-P(θ1-(t-T))24θ1(t-T)(-Tθ2)θ2TEq3

主权项

1. A method for the continuous synthesis of a modified diene elastomer, comprising the steps:
of anionic polymerization of at least one conjugated diene monomer in the presence of a polymerization initiator, of modifying the diene elastomer in a functionalizing device, by bringing the living diene elastomer bearing an active site obtained in the previous step into contact, in a single step, with a non-polymerizable functionalizing agent comprising (a) where appropriate, a function capable of interacting with a reinforcing filler and (b) a trialkoxysilane group, the optionally hydrolysable alkoxy radical having 1 to 10 carbon atoms,
the modification comprising three reactions in seriesReactionMechanismR1R2R3 where
A represents the functionalizing agent,PLi represents a living elastomer chain,PA represents the chain-end functionalized elastomer,P2A represents the coupled elastomer,P3A represents the three-arm star-shaped elastomer, andki represents the rate constant of the reaction Ri, that are carried out according to the following rate law:ReactionsRate of reactionR1V1 = k1[PLi][A]R2V2 = k2[PLi][PA]R3V3 = k3[PLi][P2A] where
k1, k2 and k3 are the rate constants respectively of the reactions R1, R2 and R3 (expressed in (m3/mol)·s−1),[PLi] is the concentration of living chains (expressed in mol/m3),[A] is the concentration of modifying agent A (expressed in mol/m3),[PA] is the concentration of chain-end functionalized elastomer (expressed in mol/m3),[P2A] is the concentration of coupled elastomer (expressed in mol/m3),[P3A] is the concentration of the three-arm star-shaped elastomer (expressed in mol/m3), with a ratio of the rate constants, defined as:K=k1k2=k2k3,  of greater than 1, and
the residence time distribution in a functionalizing device (i) or (ii) is expressed respectively according to equations 1 or 3 below: (i) in a functionalizing device having at least one tubular continuous reactor or having at least one cascade of at least two stirred reactors,E1(t)=12(Pπθ1t)12-P(θ1-t)24θ1tEq1in which:
P is the dimensionless parameter of resistance to dispersion, θ1 is the residence time defined as the reactor volume/total volume flow rate ratio, preferably equal to at least 0.1 minute and at most to 10 minutes, more preferably at most to 5 minutes, t is the variable time of the residence time distribution,
(ii) in a functionalizing device that is a combination of the device (i) and of a device having at least one continuous stirred reactor, having a residence time distribution characterized by the following equation:E2(t)=(-tθ2)θ2Eq2 in which: θ2 is the residence time defined as the reactor volume/total volume flow rate ratio, preferably between 0 and 60 minutes, more preferably between 5 and 50 minutes, t is the variable time of the residence time distribution,
the device (ii) having a residence time distribution characterized by the equation 3 below, which is the result of the convolution of equations 1 and 2:E12(t)=∫0tE1(t-T)E2(T)TE12(t)=∫0t12(Pπθ1(t-T))12-P(θ1-(t-T))24θ1(t-T)(-Tθ2)θ2TEq3 in which: θ1 and θ2 are the residence times as defined above, P is the dimensionless parameter of resistance to dispersion, t is the variable time of the residence time distribution, T is the integration variable.