Supported Metallocene-Iron Catalyst System for Olefin Polymerization

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current catalyst systems for olefin polymerization struggle to produce polyolefin compositions with specific combinations of comonomer content, molecular weights, and densities, often resulting in reduced catalytic activity and interference between catalysts in mixed systems, which limits the production of polymers with unique properties like high stiffness, toughness, and good processability.

Innovation Solution

A catalyst system comprising a Group 4 metallocene catalyst and a 2,6-bis(imino)pyridyl iron complex is used for olefin polymerization, allowing for the production of ethylene polymer compositions with controlled comonomer content and molecular weight distribution, enabling the creation of polymers with enhanced properties such as high stiffness, toughness, and good processability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple catalysts are combined in a mixed catalyst system to produce polyolefin compositions with specific properties (comonomer content, molecular weight, density), then the ability to produce polymers with unique properties (stiffness, toughness, processability) is improved, but catalyst interference occurs which reduces catalytic activity

Engineering Contradiction:

Improveability to produce polyolefin compositions with specific propertiesVSAvoidcatalytic activity

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The invention divides the catalyst system into two separate supported catalyst components rather than using a mixed liquid catalyst system. Each supported catalyst is immobilized on its own support particles, creating spatial segmentation that prevents catalyst-cocatalyst interference while maintaining individual catalytic activities. This segmentation allows each catalyst to function independently with its optimized cocatalyst ratio.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention introduces support particles as an intermediary carrier for the catalyst compounds. The supports act as mediators that hold the catalysts in a fixed phase, enabling the use of solid supported catalysts instead of liquid catalysts. This intermediary approach allows for better control of catalyst-cocatalyst ratios and prevents harmful interactions between different catalyst components.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If conventional Ziegler-Natta or chromium based catalysts are used, then broad composition distributions are produced which influence copolymer properties, but the ability to control molecular weight distribution and comonomer content precisely is limited

Engineering Contradiction:

Improvecomposition distribution controlVSAvoidcontrol of molecular weight and comonomer content

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The invention applies local quality by creating two distinct supported catalyst components, each with its own specific catalytic properties and optimization parameters. The first supported catalyst component has different characteristics from the second, allowing each to contribute differently to the overall polymer composition distribution. This local differentiation enables precise control over molecular weight distribution and comonomer content through the synergistic combination of catalysts with complementary properties.

Inventive Principle:

Principle #3Local quality

3Strength

If high molecular weight polyolefins are produced to achieve desirable mechanical properties, then toughness and strength are improved, but processing difficulty and production cost increase

Engineering Contradiction:

Improvemechanical propertiesVSAvoidprocessing difficulty and production cost

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The invention merges two supported catalyst components into a single reactor system to produce a polyolefin composition with bimodal or broad molecular weight distribution. The combination of catalysts with different molecular weight characteristics allows the simultaneous production of high molecular weight fractions (providing toughness and strength) and lower molecular weight fractions (providing processability). This merging approach achieves the desired balance of mechanical properties and processing ease in a single polymer product.

Inventive Principle:

Principle #5Merging (Combining)

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 catalyst system effectively produces ethylene polymers with tailored properties, including high comonomer content, controlled molecular weight distribution, and improved processing characteristics, overcoming the limitations of existing systems by minimizing catalyst interference and enhancing polymer properties.

Implementation Method 1

catalyst systems including the produce of the combination of an unbridged Group 4 indenyl metallocene catalyst and a 2,6-bis(imino)pyridyl iron complex

Methodology Applied

Scientific EffectCatalysis: Catalysis

Data Source

PatentUS10926250B2Catalyst systems and polymerization processes for using the same

Publication Date: 2021.02.23 EXXONMOBIL CHEMICAL PATENTS INC

AI summary

A catalyst system including the product of the combination of an unbridged Group 4 metallocene compound and a 2,6-bis(imino)pyridyl iron complex is provided. A process for the polymerization of monomers (such as olefin monomers) and a polymer produced therefrom are also provided.