Method for the continuous preparation of a catalytic system that is used to polymerize a conjugated diene and installation for implementing same

1. A process for continuous preparation of a catalytic system that can be used for polymerization of at least one conjugated diene monomer, said catalytic system being based on at least:

a preforming conjugated diene;

an organic phosphoric acid salt of one or more rare-earth element(s), said salt being in solution in at least one saturated aliphatic or alicyclic and inert hydrocarbon-based solvent;

an alkylating agent comprising an alkylaluminium having the formula AlR 3 or HAlR 2 , in which R represents an alkyl radical, and H represents a hydrogen atom; and

a halogen donor comprising an alkylaluminium halide;

which comprises successively in one line:

(i) an alkylation reaction between the preforming conjugated diene, with a solution of the salt of rare-earth element(s) and the alkylating agent, the alkylation reaction being carried out for a period of at least 5 minutes in an alkylation reactor composed of at least one well-mixed dynamic mixer; and

(ii) addition of said halogen donor to the mixture obtained in (i) that has been removed from the alkylation reactor, and introduction of the mixture obtained in (i) to a continuous halogenation-ageing reactor, to produce a reaction for halogenation-ageing of the preformed catalytic system and to continuously produce said preformed catalytic system at an outlet of said line.

2. The process according to claim 1 , wherein all of the preforming conjugated diene, of the solution of rare-earth element(s) and of the alkylating agent, are introduced directly into the alkylation reactor.

3. The process according to claim 1 , which comprises, prior to step (i), bringing said solvent(s) and said salt into contact in a solubilization reactor.

4. The process according to claim 3 , which comprises introducing said salt and then said solvent(s) into said solubilization reactor.

5. The process according to claim 3 , which comprises introducing all or a part of the preforming conjugated diene into said solubilization reactor.

6. The process according to claim 3 , wherein the solution of the salt of rare-earth element(s) evacuated from the solubilization reactor is subsequently brought into contact, in the line, with all or a part of the preforming conjugated diene.

7. The process according to claim 6 , which comprises introducing all or a part of the preforming conjugated diene into a well-mixed dynamic mixer.

8. The process according to claim 3 , wherein the temperature of said solubilization reactor is controlled at a temperature ranging from 10° C. to 100° C.

9. The process according to claim 8 , wherein the temperature of said solubilization reactor is controlled in such a way that it is approximately equal to 30° C.

10. The process according to claim 3 , wherein the continuous bringing into contact, with mixing in said line, of said solution of the salt of rare-earth element(s) with said preforming conjugated diene is carried out at a controlled temperature ranging from 10° C. to 60° C.

11. The process according to claim 10 , wherein the continuous bringing into contact, with mixing in said line, of said solution of the salt of rare-earth element(s) with said preforming conjugated diene is carried out at a controlled temperature approximately equal to 30° C.

12. The process according to claim 1 , wherein the solution of the salt of rare-earth element(s) is diluted in the line.

13. The process according to claim 12 , wherein the dilution is carried out before or after a feed pump for the line located upstream of the alkylation reactor.

14. The process according to claim 1 , wherein said catalytic system comprises said rare-earth element(s) in a concentration ranging from 0.002 mol/l to 0.08 mol/l.

15. The process according to claim 1 , wherein step (i) is carried out at a controlled temperature ranging from 25° C. to 80° C. and for a period ranging from 10 to 60 minutes.

16. The process according to claim 15 , wherein step (i) is carried out at a controlled temperature approximately equal to 30° C. and for a period approximately equal to 15 minutes.

17. The process according to claim 16 , which comprises controlling the residence time of said alkylating agent into said line, before adding said halogen donor.

18. The process according to claim 17 , wherein said controlling of the residence time in the alkylation reactor comprises controlling the size and/or the number and/or the volume of the tank(s) of the well-mixed dynamic mixer(s).

19. The process according to claim 15 wherein the halogen donor is introduced into the line before the halogenation-ageing reactor.

20. The process according to claim 15 , which comprises, following step (i), continuously bringing into contact, in the halogenation-ageing reactor, the product of said alkylation reaction with said halogen donor, at a controlled temperature ranging from 40° C. to 80° C. and for a period ranging from 10 minutes to 2 hours.

21. The process according to claim 20 , which comprises, following step (i), continuously bringing into contact, in the halogenation-ageing reactor, the product of said alkylation reaction with said halogen donor, at a controlled temperature approximately equal to 60° C. and for a period approximately equal to 60 minutes.

22. The process according to claim 20 , which comprises controlling the residence time of the ageing in said line by controlling the size and/or the number and/or the volume of the tank(s) of the well-mixed dynamic mixer(s) and/or of one or more tubular reactor(s).

23. The process according to claim 14 , which comprises, prior to step (i), continuously bringing into contact, with mixing in the line, said salt of rare-earth element(s) prepared directly in the solvent with said preforming conjugated diene at a controlled temperature ranging from 10° C. to 60° C.

24. The process according to claim 14 , wherein said catalytic system comprises said rare-earth element(s) in a concentration ranging from 0.02 mol/l to 0.04 mol/l.

25. The process according to claim 1 , wherein said catalytic system is stored downstream of said line at a temperature greater than −25° C. and less than or equal to +20° C.

26. The process according to claim 1 , wherein said alkylating agent is diisobutylaluminium hydride.

27. The process according to claim 1 , wherein said halogen donor is an alkylaluminium monohalide.

28. The process according to claim 1 , wherein said salt is a tris[bis(2-ethylhexyl)phosphate] of rare-earth element(s).

29. The process according to claim 26 , wherein the (alkylating agent/salt) molar ratio has a value ranging from 1.3 to 15.

30. The process according to claim 29 , wherein the (alkylating agent/salt) molar ratio has a value equal to 2.

31. The process according to claim 1 , wherein the (halogen/salt) molar ratio has a value ranging from 2 to 3.5.

32. The process according to claim 1 , wherein the (preforming conjugated diene/salt) molar ratio has a value ranging from 15 to 70.

33. A process for continuous preparation of a polymer of at least one conjugated diene using a continuously catalytic system, comprising:

continuously preparing a catalytic system for polymerization of at least one conjugated diene monomer according to claim 1 ;

continuously feeding at least one conjugated diene monomer to a polymerization reactor; and

feeding the catalytic system for polymerization of at least one conjugated diene monomer into the polymerization reactor.

34. The process according to claim 33 , wherein the catalytic system is prepared continuously with an installation comprising:

(i) a continuous alkylation reactor which is composed of one or more, (n), continuous alkylation, well-mixed dynamic mixer(s);

(ii) a continuous halogenation-ageing reactor which comprises one or more, (n′), well-mixed dynamic mixer(s) and optionally one or more, (n″), plug-flow tubular reactor(s) connected to the outlet of the line

(n) and (n′) being an integer greater than 0 and n″ being equal to 0 or an integer greater than 0.