Asymmetrical Phthalic Diester Catalyst for Gas-Phase Polymerization
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Solution Overview
Problem
Existing olefin polymerization catalysts exhibit high initial activity but rapidly decrease in activity over time, leading to issues such as catalyst particle breakage and the production of excessive fine powdery polymer during gas-phase polymerization, necessitating the development of a catalyst with long-lasting activity.
Innovation Solution
A solid catalyst component comprising magnesium, titanium, a halogen, and an internal electron donor, specifically an asymmetrical phthalic diester, is used to maintain olefin polymerization activity over time by suppressing initial activity through a controlled molar ratio and composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a solid catalyst component with high initial activity is used for gas-phase polymerization, then polymerization activity is improved in the initial stage, but the catalyst particles break and fine powdery polymer is produced due to heat generation
Solution Approach 1:
The patent modifies the chemical composition parameters of the catalyst system by introducing a specific organometallic compound (Formula 1) with defined molecular structure and stoichiometric ratios. This parameter change transforms the catalyst's activity profile from high initial activity to suppressed initial activity with long-lasting activity, preventing particle breakage while maintaining productivity.
Solution Approach 2:
The patent creates a composite catalyst system combining multiple components: the solid catalyst component (magnesium, titanium, halogen), the specific organometallic compound (Formula 1), an organoaluminum compound, and an organosilicon compound. This composite formulation synergistically reduces initial activity and heat generation while maintaining long-term polymerization capability.
2Productivity
If a solid catalyst component exhibiting high initial activity is used, then polymerization activity is improved initially, but polymerization activity rapidly decreases with the passage of time
Solution Approach 1:
The patent changes the activity-time profile parameter by incorporating the specific organometallic compound (Formula 1) with controlled molar ratios. This modifies the catalyst's temporal behavior from rapid activity decline to sustained long-lasting activity, extending the duration of effective polymerization.
Solution Approach 2:
The patent ensures continuous polymerization activity by suppressing the initial burst reaction that causes rapid activity loss. The modified catalyst system maintains steady, continuous activity throughout the polymerization process, eliminating the need to terminate the reaction due to activity decay.
3Productivity
If a known olefin polymerization catalyst is used for liquid polymerization, then high polymerization activity is achieved, but polymerization activity decreases when used for gas-phase polymerization
Solution Approach 1:
The patent adjusts the catalyst system parameters by adding the specific organometallic compound (Formula 1) and optimizing the ratio of organoaluminum to organosilicon compounds. This parameter modification enables the catalyst to adapt effectively to gas-phase polymerization conditions while maintaining high activity, resolving the incompatibility between liquid and gas phase processes.
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 component achieves sustained olefin polymerization activity with reduced heat generation and improved stereospecificity, minimizing the production of fine and coarse powders, and maintaining high polymerization activity during gas-phase polymerization.
Implementation Method 1
a solid catalyst component for olefin polymerization includes magnesium, titanium, a halogen, and an internal electron donor, the solid catalyst component including an asymmetrical phthalic diester
Implementation Method 2
a solid catalyst component for olefin polymerization and an olefin polymerization catalyst that exhibit long-lasting activity
Implementation Method 3
shows a phenomenon in which a strong exothermic reaction occurs in the initial stage of polymerization
Data Source
AI summary
A solid catalyst component for olefin polymerization and a catalyst are disclosed that exhibit high catalytic activity when used for gas-phase polymerization, suppress rapid reactions in the initial stage of polymerization relative to the polymerization activity, and can produce a propylene polymer in high yield while maintaining high stereoregularity. The solid catalyst component for olefin polymerization includes magnesium, titanium, a halogen, and an internal electron donor, the solid catalyst component including an asymmetrical phthalic diester represented by the following general formula (1) in a molar ratio of 0.2 to 0.8 relative to the total content of the internal electron donor.R1k(C6H4-k)(COOR2)(COOR3) (1)wherein R1 is an alkyl group or the like, R2 is a linear or branched alkyl group having 2 to 6 carbon atoms or an alkenyl group, R3 is a linear or branched alkyl group having 1 to 5 carbon atoms, the number of carbon atoms included in R3 being smaller than the number of carbon atoms included in R2, and k is an integer from 0 to 4 that indicates the number of substituents R1.