Ethylene Solution Polymerization Catalysts That Suppress Hydrogen Termination

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing catalyst systems struggle to produce high molecular weight polymers efficiently at high polymerization temperatures (120° C. to 250° C.) while maintaining high reactivity and avoiding hydrogen generation.

Innovation Solution

A non-hydrogen-generating post-metallocene procatalyst and hydrogenation procatalyst system, including a catalyst composition with specific cyclopentadienyl groups and aluminum alkyl species, is used to polymerize ethylene and α-olefins in solution processes, allowing for high molecular weight polymer production without hydrogen generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If existing catalyst systems are used at high polymerization temperatures (120°C to 250°C), then polymerization reaction rate increases, but hydrogen is generated which terminates polymerization chains and reduces molecular weight

Engineering Contradiction:

Improvepolymerization reaction rateVSAvoidhydrogen generation

Core Design Contradiction:

SpeedVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a hydrogenation procatalyst that converts the harmful hydrogen (which terminates polymerization chains) into useful hydrogen that saturates vinyl groups on the polymer chain ends. This transforms the harmful chain-termination effect into a beneficial chain-saturation effect, allowing high molecular weight polymers to be produced at elevated temperatures without the detrimental effects of hydrogen-induced termination

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The hydrogenation procatalyst acts as an intermediary component between the main group IV catalyst and the hydrogen byproduct. It mediates the interaction by capturing the hydrogen and converting it into a form that benefits the polymerization process, thereby resolving the contradiction between maintaining high reaction rates and avoiding hydrogen-induced molecular weight reduction

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If high polymerization temperatures (120°C to 250°C) are used, then productivity increases, but catalyst efficiency and molecular weight control become difficult

Engineering Contradiction:

Improvepolymer production rateVSAvoidmolecular weight control

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the system by introducing the hydrogenation procatalyst and selecting specific group IV metals (Ti, Zr, Hf) with appropriate ligands. This parameter change enables the system to maintain high molecular weights (exceeding 100,000 g/mol) even at elevated temperatures, thereby achieving both high productivity and reliable molecular weight control simultaneously

Inventive Principle:

Principle #35Parameter changes

3Productivity

If group IV metallocene catalysts are used, then polymerization activity is high, but hydrogen is generated as a byproduct which reduces polymer molecular weight

Engineering Contradiction:

Improvecatalyst activityVSAvoidhydrogen byproduct

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The hydrogenation procatalyst converts the harmful hydrogen byproduct into a beneficial agent that saturates vinyl end-groups on the polymer chains. This eliminates the harmful chain-transfer reactions while maintaining the high polymerization activity of the group IV catalyst, thereby resolving the contradiction between catalyst productivity and hydrogen byproduct formation

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 system enables the production of high molecular weight polymers with high efficiency and reactivity at elevated temperatures, exceeding 100,000 g/mol, suitable for various polymer applications.

Implementation Method 1

a hydrogenation procatalyst having the formula Cp2TiX2 or Cp2TiXnTiCp2

Methodology Applied

Scientific EffectHydrogenation: Hydrogenation

Implementation Method 2

a non-hydrogen-generating post-metallocene procatalyst; a co-catalyst; and a hydrogenation procatalyst

Methodology Applied

Scientific EffectCatalysis: Catalysis

Data Source

PatentUS12466901B2Polymerization of ethylene in solution processes using a Ziegler-Natta catalyst and a hydrogenation procatalyst

Publication Date: 2025.11.11 DOW GLOBAL TECHNOLOGIES LLC

AI summary

Processes of polymerizing olefin monomers and catalyst systems. The catalyst systems include a non-hydrogen-generating post-metallocene procatalyst; a co-catalyst; and a hydrogenation procatalyst having the formula Cp2TiXnTiCp2 or Cp2TiXn, in which each Cp is cyclopentadienyl substituted with at least one (C1-C10)alkyl; each X is independently monoanionic or neutral, wherein each X is independently (C1-C40)hydrocarbon, (C1-C40)heterohydrocarbon, (C1-C40)hydrocarbyl, (C1-C40)heterohydrocarbyl, or a halogen atom; and n is 1 or 2.