Cyclic Carbodiimide Polyester End-Sealing Odor Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing resin compositions using linear or macrocyclic carbodiimide compounds for end-sealing of polymers face issues such as the liberation of isocyanate compounds, leading to unpleasant odors and reduced utility due to low concentration and instability at high temperatures, particularly for polymers with high melting points like polyesters.
Innovation Solution
A resin composition comprising a polyester and a cyclic carbodiimide compound with a single carbodiimide group, where the first and second nitrogen atoms are bonded by a bond group, preventing the liberation of isocyanate compounds and enhancing stability, allowing for effective end-sealing without the drawbacks of existing carbodiimide compounds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a linear carbodiimide compound is used as an end-sealing agent for polyester, then the end-sealing function is achieved, but isocyanate compound is liberated causing unpleasant smell and deteriorating work environment
Solution Approach 1:
The patent changes the molecular structure parameter of the carbodiimide compound from linear to cyclic form, which fundamentally alters the reaction pathway. The cyclic structure prevents the formation of free isocyanate groups during the end-sealing reaction with polyester carboxyl groups, thereby eliminating the unpleasant smell while maintaining the end-sealing function.
Solution Approach 2:
The invention creates a composite molecular structure by incorporating the carbodiimide group within a cyclic framework rather than using a simple linear chain. This structural composite approach ensures that the carbodiimide functionality is retained for end-sealing while the cyclic architecture constrains the molecular rearrangement that would otherwise produce free isocyanate compounds.
2Stability of the object's composition
If a macrocyclic carbodiimide compound is used, then the cyclic structure is formed, but the concentration is low requiring many days for reaction reducing utility
Solution Approach 1:
The patent optimizes the ring size parameter of the cyclic carbodiimide compound to achieve an optimal balance between stability and reactivity. By controlling the number of atoms in the cyclic structure and the specific bond group connecting the nitrogen atoms, the invention achieves both sufficient cyclic stability and adequate reaction speed for practical applications.
3Stability of the object's composition
If a macrocyclic carbodiimide compound with long chain is used, then cyclic structure is formed, but it is readily decomposed at high temperature making it unsuitable for high melting point polymers
Solution Approach 1:
The patent carefully selects and optimizes the bond group connecting the first and second nitrogen atoms in the cyclic carbodiimide structure. By adjusting the chemical composition and structure of this bond group, the invention achieves enhanced thermal stability that allows the compound to withstand high temperatures without decomposition, making it suitable for end-sealing high melting point polymers like polyester.
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 solution effectively seals the ends of polyesters without producing isocyanate-related odors and maintains stability at high temperatures, improving the utility and safety of the resin composition.
Implementation Method 1
a compound having only one carbodiimide group in one cyclic structure does not liberate an isocyanate compound even when it reacts with an end of a polyester
Data Source
AI summary
A resin composition which comprises a polyester and is free from a smell produced from a free isocyanate compound. The resin composition comprises a polyester (component A) whose end is modified and a compound including a cyclic structure having one carbodiimide group whose first nitrogen and second nitrogen are bonded together by a bond group (component B).