Solid Titanium Catalyst for Broad Olefin Molecular Weight Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing catalysts for producing olefin polymers with broad molecular weight distributions and high melt tension are inefficient, resulting in high production costs and limited market acceptance due to narrow molecular weight distributions and poor moldability.
Innovation Solution
A process using a solid titanium catalyst component comprising titanium, magnesium, halogen, and a specific cyclic ester compound, along with an organometallic compound catalyst, at elevated internal pressure in the polymerization vessel to produce olefin polymers with broad molecular weight distributions and high melt tension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional catalysts are used to produce olefin polymers, then the polymerization activity and stereosspecificity are high, but the molecular weight distribution is narrow which results in low melt flowability and poor moldability
Solution Approach 1:
The patent changes the molecular weight distribution parameter by using a catalyst system with specific electron donors (cyclic carboxylic acid esters with 5-10 carbon atoms in the ring) to produce polymers with broad molecular weight distribution (Mw/Mn ≥ 6.0), thereby improving melt flowability and moldability while maintaining polymerization activity and stereospecificity
2Strength
If multi-stage polymerization is used to broaden molecular weight distribution, then the melt tension is improved, but the process complexity and production cost increase
Solution Approach 1:
The patent achieves broad molecular weight distribution and high melt tension through a single-stage polymerization process by optimizing the catalyst system parameters, specifically using cyclic carboxylic acid esters with 5-10 carbon atoms in the ring structure, thereby avoiding the complexity of multi-stage polymerization while still achieving the desired melt tension improvement
3Strength
If catalysts with specific electron donors are used to broaden molecular weight distribution, then the melt tension is improved, but the production cost increases due to limited market acceptance
Solution Approach 1:
The patent optimizes the catalyst system by using cyclic carboxylic acid esters with specific ring sizes (5-10 carbon atoms) to achieve the right balance between melt tension and production cost, creating a catalyst system that is both effective and economically viable for industrial production
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 process achieves olefin polymers with improved rigidity, high-speed stretchability, and moldability, addressing the limitations of existing catalysts by broadening molecular weight distributions and enhancing polymer properties.
Implementation Method 1
a catalyst for olefin polymerization comprising a solid titanium catalyst component (I) which comprises titanium, magnesium, halogen and a cyclic ester compound (a) specified by formula (1)... and an organometallic compound catalyst component (II)
Implementation Method 2
at an internal pressure of the polymerization vessel which is 0.25 times or more as high as the saturation vapor pressure of the olefin at a polymerization temperature
Data Source
AI summary
The process for producing an olefin polymer according to the present invention is characterized in that it comprises polymerizing an olefin having 3 or more carbon atoms in the presence of a catalyst for olefin polymerization containing a solid titanium catalyst component (I) which contains titanium, magnesium, halogen, and a cyclic ester compound (a) specified by the following formula (1):wherein n is an integer of 5 to 10,R2 and R3 are each independently COOR1 or a hydrogen atom, and at least one of R2 and R3 is COOR1; and R1's are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms, anda single bond (excluding Ca—Ca bonds, and a Ca—Cb bond in the case where R3 is a hydrogen atom) in the cyclic backbone may be replaced with a double bond, andan organometallic compound catalyst component (II),at an internal pressure of the polymerization vessel which is 0.25 times or more as high as the saturation vapor pressure of the olefin at a polymerization temperature.According to this process, an olefin polymer having a broad molecular weight distribution can be prepared.