Hybrid Metallocene Catalyst Preparation via Controlled Water Content

Solution Overview

Problem

Existing methods for preparing supported metallocene catalysts are complex and result in insufficient catalytic activity and physical properties of polyolefins, due to the calcination process which complicates the catalyst preparation and reduces bulk density.

Innovation Solution

A method involving treating a support with a water content of 5 to 6.5% by weight with trialkyl aluminum, followed by supporting alkyl aluminoxane and a metallocene compound, using a molar ratio of trialkyl aluminum to alkyl aluminoxane of 1:10 to 1:30, and loading amounts of 6 to 20 mmol/g for alkyl aluminoxane and 0.1 to 0.5 mmol/g for the metallocene compound, to create a supported hybrid metallocene catalyst with enhanced catalytic activity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If calcination process is used to prepare supported metallocene catalyst, then highly reactive siloxane group is formed on support surface, but catalyst preparation process becomes complex and catalytic activity becomes insufficient

Engineering Contradiction:

Improvereactivity of siloxane groupVSAvoidcatalyst preparation process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the calcination step from the traditional catalyst preparation process. By using a support with controlled water content (1-5%) and treating it with alkyl aluminoxane, the method achieves high catalytic activity without requiring the complex high-temperature calcination process, thus removing an unnecessary step while maintaining effectiveness

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the key parameter of water content in the support from the traditional low water content (achieved through calcination) to a controlled range of 1-5%. This parameter change, combined with alkyl aluminoxane treatment, creates highly reactive surface groups that eliminate the need for calcination, simplifying the process while maintaining or improving catalytic activity

Inventive Principle:

Principle #35Parameter changes

2Reliability

If calcination process is used to prepare supported metallocene catalyst, then highly reactive siloxane group is formed on support surface, but bulk density and physical properties of polyolefins become insufficient

Engineering Contradiction:

Improvereactivity of siloxane groupVSAvoidbulk density of polyolefins

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The invention extracts and eliminates the calcination step from the traditional catalyst preparation process. By using a support with controlled water content (1-5%) and treating it with alkyl aluminoxane, the method achieves high catalytic activity without requiring the complex high-temperature calcination process, thus removing an unnecessary step while maintaining effectiveness

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the key parameter of water content in the support from the traditional low water content (achieved through calcination) to a controlled range of 1-5%. This parameter change, combined with alkyl aluminoxane treatment, creates highly reactive surface groups that eliminate the need for calcination, simplifying the process while maintaining or improving catalytic activity

Inventive Principle:

Principle #35Parameter changes

3Object-generated harmful factors

If traditional supported metallocene catalyst is used, then polymer deposition on reactor wall is reduced, but catalytic activity and bulk density are insufficient

Engineering Contradiction:

Improvepolymer deposition on reactor wallVSAvoidcatalytic activity

Core Design Contradiction:

Object-generated harmful factorsVSProductivity

Solution Approach 1:

The invention creates a composite catalyst system combining a support with controlled water content (1-5%), alkyl aluminoxane, and metallocene compound. This composite structure provides both the anti-fouling properties of supported catalysts and the high catalytic activity needed for productive polymerization, achieving both benefits simultaneously

Inventive Principle:

Principle #40Composite materials

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

This method simplifies the catalyst preparation, increases catalytic activity, and enables the production of polyolefins with high bulk density and excellent physical properties, reducing production costs and energy consumption.

Implementation Method 1

treating a support having a water content of approximately 5 to 6.5% by weight with trialkyl aluminum

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

subsequently supporting alkyl aluminoxane on the previously treated support

Methodology Applied

Scientific EffectAdsorption: Adsorption

Data Source

PatentEP2623522B1Preparation method of hybrid supported metallocene catalyst

Publication Date: 2018.08.29 LG CHEM LTD

AI summary

The present invention relates to a preparation method of a metallocene catalyst. More particularly, the present invention relates to a preparation method of a supported hybrid metallocene catalyst, including the steps of treating a support having a water content of 4 to 7% by weight with trialkyl aluminum at a predetermined temperature; supporting alkyl aluminoxane on the support; and supporting a metallocene compound on the alkyl aluminoxane-supported support. According to the present invention, it is possible to prepare a supported hybrid metallocene catalyst which shows a high activity in the polymerization of olefins and enables the preparation of polyolefins having a high bulk density, by a simple process.