JPH1060030A - Polymerization method of unsaturated monomer - Google Patents

Abstract

(57) [Problem] To solve the problems of conventionally known lanthanide-based catalysts such as insufficient activity per catalyst or the molecular weight of the obtained polymer is not sufficiently high, and to provide a lanthanide-based catalyst. Provided is a method for efficiently polymerizing an unsaturated monomer using the same. SOLUTION: The following general formula (wherein, R ¹ is the same or different group selected from hydrogen, a hydrocarbon residue and a substituted silyl group, n is 0 to 5, R ² is a hydrocarbon residue and a substituted silyl group) The same or different groups selected, M is a metal selected from Y, Sm, and La; X is an electron donating ligand having an oxygen, nitrogen or phosphorus atom, and m is 0 to 2). And the unsaturated monomer is contacted to polymerize the unsaturated monomer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for polymerizing an unsaturated monomer. Specifically, the present invention relates to a method for polymerizing an unsaturated monomer using a specific organometallic complex.

[0002]

2. Description of the Related Art There are known various catalyst systems which can be used for producing an addition polymer by polymerizing an unsaturated monomer. Among them, a catalyst comprising a metallocene compound has a high degree of freedom of the compound. Much research has been done because of its large potential. Among them, when a lanthanide-based metal is used as the central metal, development is expected because it is not necessary to use an organic metal compound such as aluminoxane in combination, and further, the polymerization proceeds in a living manner.

[0003]

The conventionally known catalysts composed of lanthanide-based metals have the above-mentioned characteristics, but have insufficient activity per catalyst or the molecular weight of the obtained polymer is not sufficiently high. There is a problem and the development of a more improved catalyst system is desired.

[0004]

Means for Solving the Problems The present inventors diligently studied a polymerization method using a lanthanide-based catalyst which solved the above-mentioned problems, and completed the present invention.

That is, the present invention relates to a compound represented by the following general formula (3): wherein R ¹ is the same or different group selected from hydrogen, a hydrocarbon residue and a substituted silyl group, n is 0 to 5, and R ² is The same or different groups selected from a hydrogen residue and a substituted silyl group, M is a metal selected from Y, Sm, and La; X is an electron donating ligand having an oxygen, nitrogen or phosphorus atom; A) contacting the unsaturated monomer with the lanthanide complex represented by the formula (1).

[0006]

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[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The lanthanide catalyst of the present invention comprises:
It is a compound represented by the above general formula (Formula 3), wherein the ligand has a structure in which one is a cyclopentadienyl group, and two are a hydrocarbon residue and a substituted silyl group. Specifically, the cyclopentadienyl group is preferably a cyclopentadienyl group in which 1 to 5 hydrogens of the cyclopentadienyl group are substituted with a hydrocarbon residue or a substituted silyl group. Here, examples of the hydrocarbon residue include methyl, ethyl, propyl, butyl, pentyl, phenyl, and cyclohexyl groups, and examples of the silyl group include silyl, methylsilyl, dimethylsilyl, and trimethylsilyl. A hydrocarbon residue bonded to a lanthanide metal, or a substituted silyl group having a structure of bonding to a metal at a secondary or tertiary carbon, or a structure having a structure of bonding to a metal at one to three carbon atoms bonded to a substituted silyl group Are preferably exemplified.

Examples of the central metal include trivalent yttrium (Y), samarium (Sm), and lanthanum (La).

The preferred cyclopentadienyl group is a substituted cyclopentadienyl group, and the two hydrocarbon residues are those having a structure in which the tertiary carbon is bonded to a lanthanide metal. More preferably, it is a compound having a structure represented by the following general formula (Formula 4) (where Me is a methyl group).

[0010]

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Examples of the electron donating ligand having an oxygen, nitrogen or phosphorus atom include ethers, amines and phosphines. Specifically, ethers include diethyl ether, tetrahydrofuran, dioxane, dimethoxyethane, etc., amines include dimethylamine, trimethylamine, pyridine, lutidine, etc., and phosphines include trimethylphosphine, triphenylphosphine, etc. Is exemplified.

As the polymerization conditions, ordinary polymerization conditions can be adopted, and the polymerization conditions are -100 to 200 ° C., normal pressure to 100 kg / cm ^2.
Generally, a solvent polymerization method, a bulk polymerization method, and a gas phase polymerization method can be employed.

The unsaturated monomer that can be used in the present invention is not particularly limited as long as it is an addition-polymerizable unsaturated monomer. Examples include olefins such as ethylene, propylene, pentene, hexene, heptene, octene, and styrene; esters of acrylic acid; and esters of methacrylic acid.

[0014]

The present invention will be further described with reference to the following examples.

Example 1 Synthesized according to the following literature, that is, LaI _{3 in} THF
And La obtained by reacting η ⁵ -C ₅ Me _{5 with} a potassium salt
(Η ⁵ -C ₅ Me ₅ ) I ₂ (THF) ₃ was reacted with KCH (SiMe ₃ ) _{2 in a} mixed solution of hexane and diethyl ether to obtain a tetramethylcyclopentadienyl group and two bis Lanthanum complex represented by the following general formula (Formula 5) to which a (trimethylsilyl) methyl group is bonded (where Me is a methyl group) (CJ Schaverien et al., Organometallic
s, 1989, 8, 255) was polymerized ethylene using.

[0016]

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Using this complex, ethylene was polymerized at normal pressure and normal temperature in toluene (the concentration of the lanthanum complex was 2 mmol / L). 10
The number average molecular weight of 3550 g per mole of the catalyst is 1310 per minute.
000 polyethylene were obtained. Although the ratio of the weight average molecular weight to the number average molecular weight is slightly wide, about 1.6 to 1.8, the molecular weight increases with the passage of time.

Example 2 The procedure of Example 1 was repeated except that styrene was used as the monomer. However, the concentration of styrene was 1 mol% and the polymerization temperature was 5
0 ° C. In 4 hours, the yield was 62%, the number average molecular weight of the obtained polymer was 7,180, and the ratio of the weight average molecular weight to the number average molecular weight was about 1.6.

[0019]

According to the present invention, the unsaturated monomer can be efficiently polymerized by carrying out the method of the present invention, which is extremely valuable industrially.

Claims (2)

[Claims] (1) A compound represented by the following general formula (1), wherein R ¹ is hydrogen,
The same or different groups selected from hydrocarbon residues and substituted silyl groups, n is 0 to 5, R ² is the same or different groups selected from hydrocarbon residues and substituted silyl groups, and M is selected from Y, Sm and La X is an electron donating ligand having an oxygen, nitrogen or phosphorus atom, and m is 0 to 2. A method for polymerizing an unsaturated monomer, which comprises contacting a lanthanide complex represented by the formula (1) with an unsaturated monomer. Embedded image 2. A lanthanide complex represented by the following general formula (2):
The polymerization method according to claim 1, wherein the compound is a compound represented by the formula: wherein Me is a methyl group. Embedded image