Amide-Based Zieg-Natta Catalyst for Phthalate-Free Polypropylene

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Solution Overview

Problem

Current Ziegler-Natta catalyst systems for polypropylene production, particularly those using alkyl phthalate esters as internal electron donors, face challenges in achieving high isotacticity and activity while also needing to reduce or eliminate phthalate derivatives due to environmental concerns, resulting in polypropylene products with lower isotacticity and productivity.

Innovation Solution

A Ziegler-Natta catalyst system comprising magnesium, titanium, halide, and an amide compound represented by Formula I, which includes urea derivatives, is used in conjunction with internal electron donors like 1,3-diethers and phthalic acid esters to enhance isotacticity and activity, replacing phthalate derivatives and improving polymerization outcomes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If alkyl phthalate esters are used as internal electron donors to achieve high isotacticity and activity, then polymerization activity and stereo-regularity are improved, but environmental harm increases due to phthalate derivatives

Engineering Contradiction:

Improvepolymerization activityVSAvoidenvironmental harm from phthalate derivatives

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical structure parameter of the internal electron donor from alkyl phthalate esters to amide compounds (specifically urea derivatives with formula I). This parameter change eliminates the harmful phthalate group while maintaining the electron-donating functionality needed for high polymerization activity and isotacticity. The amide compounds provide similar electronic effects without the environmental toxicity associated with phthalates.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces environmentally harmful phthalate derivatives with amide compounds that are safer and more environmentally friendly. The amide compounds serve as effective substitutes that achieve the same catalytic function without the long-term environmental persistence and toxicity of phthalates, effectively discarding the harmful substance while maintaining performance.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Object-affected harmful factors

If phthalate derivatives are reduced or eliminated to address environmental concerns, then environmental compliance is improved, but isotacticity and productivity of polypropylene decrease

Engineering Contradiction:

Improveenvironmental complianceVSAvoidisotacticity and productivity

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent changes the chemical parameter of the internal electron donor from phthalate-based structures to amide-based structures (formula I). This parameter change maintains the essential electron-donating capability needed for catalyst activity and stereocontrol while eliminating the harmful phthalate moiety. The amide compounds achieve comparable or superior isotacticity without compromising productivity.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The amide compounds act as intermediary substances that transfer the essential function of internal electron donors (controlling stereo-regularity and maintaining activity) without incorporating the harmful phthalate structure. The amide group serves as a mediator that provides the necessary electronic effects for high isotacticity while being environmentally benign.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 produces polypropylene with significantly higher isotacticity and activity compared to systems without amide compounds, achieving isotacticity of 98.1-99.6% and activities up to 4280 gPP/gcat, while being phthalate-free, thus addressing the need for improved stereo-regularity and environmental compliance.

Implementation Method 1

Ziegler-Natta catalyst components for olefin polymerization employing specific forms of amide compounds as an element of the solid catalyst composition in conjunction with one or more internal donor compounds

Methodology Applied

Scientific EffectCatalysis: Catalysis

Data Source

PatentUS20180326407A1Olefin polymerization catalyst components and process for the production of olefin polymers therewith

Publication Date: 2018.11.15 FORMOSA PLASTICS USA

AI summary

The present invention relates to a Ziegler-Natta catalyst component for olefin polymerization containing an amide element in combination with one or more internal electron donors. The catalyst components, according to the present invention, are able to produce polypropylene polymers with higher stereo-regularity. The present invention also provides a phthalate-free catalyst system capable of producing polypropylene with an isotacticity that is equal to or higher than catalyst systems containing phthalate derivatives.