Cyclopentadienyl Catalyst for High-Temperature Olefin Polymerization

Solution Overview

Problem

Current transition metal compounds with monocyclopentadienyl ligands face limitations in achieving high copolymerization reactivity and molecular weight at elevated temperatures for olefin polymers, especially with comonomers having high steric hindrance.

Innovation Solution

A novel fourth group transition metal compound, specifically formulated with a cyclopentadienyl ligand and tailored substituents, is developed to serve as a catalyst for olefin polymerization, enabling excellent copolymerization reactivity and high molecular weight at temperatures of 150°C or more, even with comonomers of high steric hindrance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional transition metal compounds with monocyclopentadienyl ligands are used for polymerization, then the polymerization process can proceed, but copolymerization reactivity and molecular weight are limited at elevated temperatures

Engineering Contradiction:

Improvecopolymerization reactivityVSAvoidmolecular weight

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent introduces specific functional groups (dialkyl amine, cyclic alkyl amine, pyridine, 8-quinoline) at particular positions on the cyclopentadienyl ligand to create localized electronic and steric environments that enhance both copolymerization reactivity and molecular weight control. This local modification of ligand properties allows simultaneous improvement of both contradictory parameters.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent systematically varies ligand substitution patterns, metal oxidation states (Ti(III), Ti(IV), Zr(IV), Hf(IV)), and coordinating group types to optimize catalyst performance. By changing these chemical parameters, the catalyst achieves high copolymerization reactivity while maintaining high molecular weight even at elevated temperatures.

Inventive Principle:

Principle #35Parameter changes

2Speed

If conventional catalysts are used for polymerization at elevated temperatures, then reaction rate increases, but copolymerization activity and degree of copolymerization decrease

Engineering Contradiction:

Improvereaction rateVSAvoidcopolymerization activity

Core Design Contradiction:

SpeedVSProductivity

Solution Approach 1:

The patent designs catalysts with dynamic electronic structures through variable metal oxidation states and flexible ligand coordination modes. This allows the catalyst to adapt to different reaction conditions, maintaining high copolymerization activity across a range of temperatures while preserving fast reaction rates.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent creates composite catalytic systems combining fourth group transition metals with specifically designed organic ligands containing multiple functional groups. This composite structure synergistically enhances both thermal stability and copolymerization activity, allowing elevated temperature operation without loss of catalytic performance.

Inventive Principle:

Principle #40Composite materials

3Productivity

If conventional catalysts are used with comonomers of high steric hindrance, then polymerization can occur, but copolymerization reactivity and degree of copolymerization are reduced

Engineering Contradiction:

Improvecopolymerization reactivityVSAvoidcompatibility with sterically hindered comonomers

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent introduces specific functional groups (dialkyl amine, cyclic alkyl amine, pyridine, 8-quinoline) at particular positions on the cyclopentadienyl ligand to create localized electronic and steric environments that enhance both copolymerization reactivity and molecular weight control. This local modification of ligand properties allows simultaneous improvement of both contradictory parameters.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent systematically varies ligand substitution patterns, metal oxidation states (Ti(III), Ti(IV), Zr(IV), Hf(IV)), and coordinating group types to optimize catalyst performance. By changing these chemical parameters, the catalyst achieves high copolymerization reactivity while maintaining high molecular weight even at elevated temperatures.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The novel compound achieves high copolymerization activity and degree of copolymerization, resulting in low-density olefin polymers with high molecular weight at elevated temperatures, demonstrating improved performance compared to existing catalysts.

Implementation Method 1

the compound can be used as a polymerization catalyst of an olefin monomer

Methodology Applied

Scientific EffectCatalysis: Catalysis

Data Source

PatentUS7972987B2Fourth group transition metal compound having cyclopentadienyl ligand, method of preparing compound, and method of preparing olefin polymer using compound

Publication Date: 2011.07.05 LG CHEM LTD

AI summary

The present invention relates to a novel cyclopentadienyl compound, a fourth group transition metal compound having the cyclopentadienyl compound, a method of preparing the fourth group transition metal compound, a method of preparing an olefin polymer by using the fourth group transition metal compound, and an olefin polymer prepared by using the method.