Process for the preparation of polyisoprene with a mainly alternating cis-1,4- alt-3,4 structure in the presence of a catalytic system comprising a pyridyl iron complex

Patent metadata

Field	Value
Publication number	US-11746167-B2
Application number	US-201916962056-A
Country	US
Kind code	B2
Filing date	Jan 16, 2019
Priority date	Jan 17, 2018
Publication date	Sep 5, 2023
Grant date	Sep 5, 2023

Abstract

Process for the preparation of polyisoprene with a mainly alternating cis-1,4-alt-3,4 structure comprising polymerizing isoprene in the presence of a catalytic system comprising:
(a) at least one pyridyl iron complex having general formula (I):

wherein:
R 1 is selected from linear or branched C 1 -C 20 , preferably C 1 -C 15 , alkyl groups, optionally substituted cycloalkyl groups, optionally substituted aryl groups;
R 2 is selected from linear or branched C 1 -C 10 , preferably C 1 -C 3 , alkyl groups; X, mutually identical or different, represent a halogen atom such as, for example, chlorine, bromine, iodine; or they are selected from linear or branched C 1 -C 20 , preferably C 1 -C 15 , alkyl groups, —OCOR 3 groups or —OR 3 groups wherein R 3 is selected from linear or branched C 1 -C 20 , preferably C 1 -C 15 , alkyl groups.
n is 2 or 3;
(b) at least one co-catalyst selected from organo-derivative compounds of aluminum, preferably from
(b 1 ) aluminoxanes having general formula (II):

(R 4 ) 2 —Al—O—[—Al(R 5 )—O—] m —Al—(R 6 ) 2   (II)

wherein R 4 , R 5 and R 6 , mutually identical or different, represent a hydrogen atom, or a halogen atom such as, for example, chlorine, bromine, iodine, fluorine; or they are selected from linear or branched C 1 -C 20 alkyl groups, cycloalkyl groups, aryl groups, said groups being optionally substituted with one or more silicon or germanium atoms; and m is an integer ranging from 0 to 1000;
(b 2 ) aluminum compounds having general formula (III):

Al(R 7 )(R 8 )(R 9 )  (III)

wherein R 7 is a hydrogen atom, or is selected from linear or branched C 1 -C 20 alkyl groups, cycloalkyl groups, aryl groups, alkylaryl groups, arylalkyl groups, alkoxy groups; R 8 and R 9 , mutually identical or different, are selected from linear or branched C 1 -C 20 alkyl groups, cycloalkyl groups, aryl groups, alkylaryl groups, arylalkyl groups;
wherein the molar ratio between the aluminum present in the co-catalyst and the iron present in the iron pyridyl complex having general formula (I) is ranging from 5 to 60, preferably from 8 to 55.

First claim

The invention claimed is:

1. A process for the preparation of polyisoprene with a mainly alternating cis-1,4-alt-3,4 structure the process comprising:
polymerizing isoprene in the presence of a catalytic system, the system comprising:
(a) at least one pyridyl iron complex having general formula (I):

wherein:
R 1 is selected from linear or branched C 1 -C 20 alkyl groups, optionally substituted cycloalkyl groups, and optionally substituted aryl groups;
R 2 is selected from linear or branched C 1 -C 10 alkyl groups;
X, mutually identical or different, represents a halogen atom; or X is selected from linear or branched C 1 -C 20 alkyl groups, —OCOR 3 groups and —OR 3 groups wherein R 3 is selected from linear or branched C 1 -C 20 alkyl groups;
n is 2 or 3;
(b) at least one co-catalyst selected from (b1) aluminoxanes having general formula (II):
(R 4 ) 2 —Al—O—[—Al(R 5 )—O—] m —Al—(R 6 ) 2   (II)

wherein R 4 , R 5 and R 6 , mutually identical or different, represent a hydrogen atom or a halogen atom; or R 4 , R 5 and R 6 are selected from linear or branched C 1 -C 20 alkyl groups, cycloalkyl groups, and aryl groups, the groups being optionally substituted with one or more silicon or germanium atoms; and m is an integer ranging from 0 to 1000;
(b2) aluminum compounds having general formula (III):
Al(R 7 )(R 8 )(R 9 )  (III)

wherein R 7 represents a hydrogen atom, or is selected from linear or branched C 1 -C 20 alkyl groups, cycloalkyl groups, aryl groups, alkylaryl groups, arylalkyl groups, alkoxy groups; R 8 and R 9 , mutually identical or different, are selected from linear or branched C 1 -C 20 alkyl groups, cycloalkyl groups, aryl groups, alkylaryl groups, and arylalkyl groups;
wherein the molar ratio between aluminum present in the co-catalyst and iron present in the pyridyl iron complex having general formula (I) ranges from 5 to 60.

2. The process according to claim 1 , further comprising the pyridyl iron complex having general formula (I), wherein:
R 1 represents a methyl group, an ethyl group, an n-propyl group, or an iso-propyl group;
R 2 represents a methyl group, an ethyl group, an n-propyl group, or an iso-propyl group;
X, mutually identical, represents a halogen atom such as chlorine, bromine, or iodine atom; and
n is 2 or 3.

3. The process according to claim 1 , wherein the aluminoxanes having general formula (II) are selected from: methylaluminoxane (MAO), ethylaluminoxane, n-butylaluminoxane, tetra-iso-butylaluminoxane (TIBAO), tert-butylaluminoxane, tetra-(2,4,4-trimethylpentyl)aluminoxane (TIOAO), tetra-(2,3-dimethylbutyl)aluminoxane (TDMBAO), tetra-(2,3,3-trimethylbutyl)aluminoxane (TTMBAO), and mixtures thereof.

4. The process according to claim 1 , wherein the aluminum compounds having general formula (III) are selected from: diethylaluminum hydride, di-n-propylaluminum hydride, di-n-butylaluminum hydride, di-iso-butyl-aluminum hydride (DIBAH), diphenylaluminum hydride, di-p-tolylaluminum hydride, dibenzyl aluminum hydride, diethylaluminum hydride, phenyl-n-propylaluminum hydride, p-tolylethylaluminum hydride, p-tolyl-n-propylaluminum hydride, p-tolyl-iso-propylaluminum hydride, benzylethylaluminum hydride, benzyl-n-propylaluminum hydride, benzyl-iso-propylaluminum hydride, diethylaluminum ethoxide, di-iso-butyl aluminum dioxide, dipropylaluminum ethoxide, trimethylaluminum, triethylaluminum (TEA), tri-n-propylaluminum, tri-iso-butylaluminum (TIBA), tri-n-butylaluminum, tripentylaluminum, trihexaluminum, tricyclohexylaluminum, trioctylaluminum, triphenylaluminum, tri-p-tolylalluminium, tribenzylaluminum, ethyldiphenylaluminum, ethyldi-p-tolylaluminum, etildibenzylaluminum, diethylphenylaluminum, diethyl-p-tolylaluminum, diethylbenzylaluminum, and mixtures thereof.

5. The process according to claim 1 , wherein:
the process is carried out in the presence of at least one inert organic solvent selected from the group consisting of: saturated aliphatic hydrocarbons; saturated cycloaliphatic hydrocarbons; mono-olefins; aromatic hydrocarbons; halogenated hydrocarbons; and/or
the concentration of the isoprene in the inert organic solvent is ranges from 5% by weight to 50% by weight, with respect to the total weight of the mixture of isoprene and inert organic solvent; and/or
the process is carried out at a temperature ranging from −30° C. to +60° C.

6. The process according to claim 1 , wherein the linear or branched C 1 -C 20 alkyl groups of R 1 is linear or branched C 1 -C 15 alkyl groups.

7. The process according to claim 1 , wherein the linear or branched C 1 -C 20 alkyl groups of R 3 is linear or branched C 1 -C 15 alkyl groups.

8. The process according to claim 1 , wherein the linear or branched C 1 -C 10 alkyl groups of R 2 is linear or branched C 1 -C 3 alkyl groups.

9. The process according to claim 1 , wherein the halogen atom is selected from the group consisting of chlorine, bromine, iodine, and fluorine.

10. The process according to claim 2 , wherein
R 1 represents a methyl group;
R 2 represents a methyl group or an iso-propyl group; and
X, mutually identical, represents a chlorine atom.

11. The process according to claim 5 , wherein the saturated aliphatic hydrocarbons are selected from the group consisting of: butane, pentane, hexane, heptane, and mixtures thereof.

12. The process according to claim 5 , wherein the mono-olefins are selected from the group consisting of: 1-butene, 2-butene, and mixtures thereof.

13. The process according to claim 5 , wherein the saturated cycloaliphatic hydrocarbons are selected from the group consisting of: cyclopentane, cyclohexane, and mixtures thereof.

14. The process according to claim 5 , wherein the aromatic hydrocarbons are selected from the group consisting of: benzene, toluene, xylene, and mixtures thereof.

15. The process according to claim 5 , wherein the halogenated hydrocarbons are selected from the group consisting of: dichloromethane, chloroform, carbon tetrachloride, trichlorethylene, perchloroethylene, 1,2-dichloroethane, chlorobenzene, bromobenzene, chlorotoluene, and mixtures thereof.

16. The process according to claim 5 , wherein the process is carried out at a temperature ranging from −20° C. to +30° C.

17. The process according to claim 5 , wherein the concentration of the isoprene in the inert organic solvent ranges from 10% by weight to 20% by weight, with respect to the total weight of the mixture of isoprene and inert organic solvent.

Assignees

• Versalis Spa

Inventors

• Ricci Giovanni
• Sommazzi Anna
• Pampaloni Guido
• Leone Giuseppe
• Masi Francesco

Classifications

• C08F136/08 Primary

  Isoprene · CPC title

• A43B1/10

  made of rubber · CPC title

• B60C1/0016

  Compositions of the tread · CPC title

• C07F15/025

  without a metal-carbon linkage · CPC title

• C08F4/7006

  NN · CPC title