Process for the preparation of branched polybutadiene having a high content of 1,4-cis units

Patent metadata

Field	Value
Publication number	US-9822198-B2
Application number	US-201314388474-A
Country	US
Kind code	B2
Filing date	Apr 24, 2013
Priority date	May 11, 2012
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

A process for the preparation of branched polybutadiene having a high content of 1,4-cis units which comprises polymerizing butadiene in the presence of at least one organic solvent, and in the presence of: a) a catalytic system prepared in situ including: (a 1 ) at least one neodymium carboxylate, (a 2 ) at least one alkyl compound of aluminum, (A 3 ) at least one alkyl compound of aluminum containing at least one halogen atom, and b) at least one organic ester containing at least one halogen atom. Said branched polybutadiene having a high content of 1,4-cis units, depending on the branching degree and molecular weight distribution, can be advantageously used in various applications ranging from the modification of plastic materials [production, for example, of high impact polystyrene (HIPS)] to the production of tires, in particular the production of treads and/or of sidewalls of tires.

First claim

The invention claimed is:

1. A process for the preparation of branched polybutadiene having a high content of 1,4-cis units, by the polymerization of butadiene in the presence of at least one organic solvent, and in the presence of:
a) a catalytic system prepared in situ including:
(a 1 ) at least one neodymium carboxylate,
(a 2 ) at least one alkyl compound of aluminum,
(a 3 ) at least one alkyl compound of aluminum containing at least one halogen atom, and

b) at least one organic ester containing at least one halogen atom,
wherein the molar ratio between the at least one organic ester containing at least one halogen atom (b) and the at least one neodymium carboxylate (a 1 ) ranges from 1/0.0005 to 1/0.0015, wherein said polymerization of said butadiene is carried out in a single reaction step and said at least one organic ester containing at least one halogen atom is directly added to the polymerization.

2. The process for the preparation of branched polybutadiene having a high content of 1,4-cis units according to claim 1 , wherein said butadiene is present in an amount ranging from 5% to 40% by weight with respect to the total weight of the at least one organic solvent.

3. The process for the preparation of branched polybutadiene having a high content of 1,4-cis units according to claim 1 , wherein the at least one organic solvent is selected from: saturated aliphatic hydrocarbons; saturated cycloaliphatic hydrocarbons; mono-olefins; halogenated hydrocarbons; or mixtures thereof.

4. The process for the preparation of branched polybutadiene having a high content of 1,4-cis units according to claim 1 , wherein the at least one neodymium carboxylate (a 1 ) is neodymium versatate [Nd(versatate) 3 ].

5. The process for the preparation of branched polybutadiene having a high content of 1,4-cis units according to claim 1 , wherein the at least one neodymium carboxylate is used in an amount ranging from 0.1 mmoles to 10 mmoles per 1000 g of butadiene to be polymerized.

6. The process for the preparation of branched polybutadiene having a high content of 1,4-cis units according to claim 1 , wherein the at least one alkyl compound of aluminum (a 2 ) is selected from compounds having general formula (I) or (II):
Al(R) 3   (I)

AlH(R) 2   (II)

wherein R represents a linear or branched C 1 -C 10 alkyl group.

7. The process for the preparation of branched polybutadiene having a high content of 1,4-cis units according to claim 1 , wherein the at least one alkyl compound of aluminum containing at least one halogen atom (a 3 ) is selected from compounds having general formula (III):
AlX n R 3-n   (III)

wherein R represents a linear or branched C 1 -C 10 alkyl group, X represents a halogen atom selected from chlorine, bromine, fluorine or iodine, n is 1 or 2.

8. The process for the preparation of branched polybutadiene having a high content of 1,4-cis units according to claim 1 , wherein the molar ratio between the at least one neodymium carboxylate (a 1 ) and the at least one alkyl compound of aluminum (a 2 ) ranges from 1/1 to 1/30.

9. The process for the preparation of branched polybutadiene having a high content of 1,4-cis units according to claim 1 , wherein the molar ratio between the at least one neodymium carboxylate (a 1 ) and the at least one alkyl compound of aluminum containing at least one halogen atom (a 3 ) ranges from 1/1.5 to 1/6.

10. The process for the preparation of branched polybutadiene having a high content of 1,4-cis units according to claim 1 , wherein the at least one alkyl compound of aluminum containing at least one halogen atom (a 3 ) is used in such an amount that the ratio between the halogen present in said compound (a 3 ) and the at least one alkyl compound of aluminum (a 2 ) ranges from 0.5 to 5.

11. The process for the preparation of branched polybutadiene having a high content of 1,4-cis units according to claim 1 , wherein the at least one organic ester containing at least one halogen atom (b) is selected from compounds having general formula (IV):

wherein:
R 1 , R 2 and R 3 , equal to or different from each other, represent a halogen atom selected from chlorine, bromine, fluorine or iodine; linear or branched C 1 -C 10 alkyl groups, linear or branched C 2 -C 10 alkenyl groups, aryl groups, cycloalkyl groups, or ester groups; with the proviso that at least one of R 1 , R 2 and R 3 is a halogen atom;
R 4 is selected from linear or branched C 1 -C 10 alkyl groups, linear or branched C 2 -C 10 alkenyl groups, or aryl groups.

12. The process for the preparation of branched polybutadiene having a high content of 1,4-cis units according to claim 1 , wherein said process is carried out at a temperature ranging from 20° C. to 120° C.

13. The process for the preparation of branched polybutadiene having a high content of 1,4-cis units according to claim 1 , wherein said process is carried out at a pressure ranging from 1 bar to 10 bar.

14. The process for the preparation of branched polybutadiene having a high content of 1,4-cis units according to claim 3 , wherein said saturated aliphatic hydrocarbons are selected from butane, n-pentane, n-hexane, n-heptane, or mixtures thereof; said saturated cycloaliphatic hydrocarbons are selected from cyclohexane, cyclopentane, or mixtures thereof; said mono-olefins are selected from 1-butene, 2-butene, or mixtures thereof; and said halogenated hydrocarbons are selected from methylene chloride, chloroform, carbon tetrachloride, trichloroethylene, perchloroethylene, 1,2-dichloroethane, chlorobenzene, bromobenzene, chlorotoluene, or mixtures thereof.

15. A process for the preparation of branched polybutadiene having a high content of 1,4-cis units, by polymerizing butadiene in the presence of at least one organic solvent, and in the presence of:
a) a catalytic system prepared in situ including:
(a 1 ) at least one neodymium carboxylate,
(a 2 ) at least one alkyl compound of aluminum, and
(a 3 ) at least one alkyl compound of aluminum containing at least one halogen atom, and

b) at least one organic ester containing at least one halogen atom,
wherein the molar ratio between the at least one organic ester containing at least one halogen atom (b) and the at least one neodymium carboxylate (a 1 ) ranges from 1/0.0005 to 1/0.0015, wherein said polymerizing of said butadiene is carried out in a single reaction step immediately followed by recovery of the branched polybutadiene having a high content of 1,4-cis units.

Assignees

• Versalis Spa

Inventors

• Vallieri Andrea
• Zinna Marianna
• Perretta Costantino

Classifications

• B60C1/00 Primary

  Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition · CPC title

• C08F236/16

  containing halogen · CPC title

• C08F36/06 Primary

  Butadiene · CPC title

• C08F136/06 Primary

  Butadiene · CPC title

• C08K3/04

  Carbon · CPC title