Polytetramethylene ether glycol, method for producing it, polyester elastomer and polyurethane
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Solution Overview
Problem
Current methods for producing polytetramethylene ether glycol with high molecular weight and narrow molecular weight distribution face challenges in separation efficiency and productivity, leading to insufficient flexibility and elastic recovery in polyurethanes and polyester elastomers.
Innovation Solution
A method involving layer separation of a mixed solution containing raw material polytetramethylene ether glycol, water, and an alcohol to obtain a polytetramethylene ether glycol with a number average molecular weight higher by 300 or more, achieving a molecular weight distribution of 1.7 to 2.2, suitable for use in polyurethanes and polyester elastomers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If layer separation is performed using conventional methods with raw material PTMG having number average molecular weight of 1,000 to 2,000, then separation can be achieved, but a polyether polyol having adequate number average molecular weight and narrow molecular weight distribution cannot be produced with high productivity
Solution Approach 1:
The invention changes the parameter of number average molecular weight of raw material PTMG from conventional 1,000-2,000 to 2,500 or more. This parameter change enables both narrow molecular weight distribution (Mw/Mn of 2.0 or less) and high productivity, as the separation process becomes more efficient with higher molecular weight raw materials, resolving the contradiction between manufacturing precision and productivity
Solution Approach 2:
The invention performs preliminary selection of raw material PTMG with specific molecular weight characteristics (number average molecular weight of 2,500 or more) before the separation process. This preliminary action ensures that the subsequent layer separation can achieve both narrow molecular weight distribution and high productivity, as the raw material properties are pre-optimized for the separation process
2Manufacturing precision
If various refining techniques such as extraction or membrane separation are used to control molecular weight or molecular weight distribution, then target polyether polyol can be produced, but productivity is reduced
Solution Approach 1:
The invention uses layer separation to extract and separate PTMG molecules based on their molecular weight differences. By using raw material PTMG with number average molecular weight of 2,500 or more, the extraction process efficiently produces polyether polyol with narrow molecular weight distribution while maintaining high productivity, avoiding the need for multiple refining steps
Solution Approach 2:
The invention changes the approach from controlling molecular weight through multiple refining techniques to controlling it through selective extraction based on molecular weight. By using raw material with number average molecular weight of 2,500 or more, the single layer separation step achieves both precise molecular weight control and high productivity
3Manufacturing precision
If layer separation is performed at low temperature (30°C or less) to separate low-molecular-weight form with good selectivity, then PTMG with narrow molecular weight distribution is obtained, but productivity decreases due to longer separation time
Solution Approach 1:
The invention changes the parameter of raw material PTMG number average molecular weight to 2,500 or more, which fundamentally alters the separation behavior. This parameter change enables the separation process to achieve narrow molecular weight distribution without requiring low temperature conditions, thus maintaining high productivity while achieving the desired molecular weight control
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 produces polytetramethylene ether glycol with enhanced flexibility and elastic recovery, improving the productivity and physical properties of polyurethanes and polyester elastomers, while maintaining low viscosity for better handleability.
Implementation Method 1
A method involving layer separation of a mixed solution containing raw material polytetramethylene ether glycol, water, and an alcohol to obtain a polytetramethylene ether glycol with a number average molecular weight higher by 300 or more
Data Source
AI summary
The present invention provides a high-molecular-weight polyether polyol ensuring that when used as a polyurethane raw material, a polyurethane having excellent flexibility and elastic recovery can be obtained; and a method for producing, with high productivity, a polyether polyol having a higher number average molecular weight and a narrower molecular weight distribution than those of the raw material polyether polyol. The polyether polyol of the present invention has a number average molecular weight of 3,500 to 5,500 and a molecular weight distribution of 1.7 to 3.0.