Polyurethane Formation Using Hindered Secondary Hydroxyl Polyols
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polyurethane reaction systems face challenges in achieving a balance of rapid cure rate, toughness, weatherability, and flexibility, particularly when using primary alcohols, which often result in materials with lower hardness and require additional polyols for optimization.
Innovation Solution
A reaction system comprising a monomeric polyol with hindered secondary hydroxyl groups, a polymeric polyol, and a zinc-containing catalyst, specifically including imidazole and carboxylate ligands, to facilitate enhanced reaction rates and optimize polyurethane properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If primary alcohols are used as the hydroxyl-functional component, then the cure rate is improved, but the hardness deteriorates
Solution Approach 1:
The patent changes the chemical parameter of the polyol from primary alcohol to polyol with secondary hydroxyl groups (specifically hindered secondary hydroxyl groups), which fundamentally alters the reaction characteristics and physical properties of the resulting polyurethane, achieving both rapid cure and high hardness
Solution Approach 2:
The patent employs a composite polyol system combining polyol with secondary hydroxyl groups and polyester polyol, creating a synergistic formulation that achieves rapid cure rate, high hardness, toughness, and flexibility simultaneously, resolving the contradiction between speed and strength
2Speed
If primary alcohols are used to achieve rapid cure, then the cure rate is improved, but the weatherability deteriorates
Solution Approach 1:
The patent changes the hydroxyl group type from primary to secondary (specifically hindered secondary), which improves both cure rate and weatherability simultaneously by altering the molecular structure and reactivity of the polyol component
Solution Approach 2:
The composite polyol formulation combining polyol with secondary hydroxyl groups and polyester polyol creates a system that achieves rapid cure while maintaining excellent weatherability and long-term durability
3Speed
If primary alcohols are used for rapid cure, then the cure rate is improved, but the flexibility deteriorates
Solution Approach 1:
The patent changes the polyol structure to contain secondary hydroxyl groups with specific steric hindrance, which enables rapid cure while the resulting polyurethane maintains flexibility and toughness due to the molecular structure characteristics
Solution Approach 2:
The patent uses a composite system of polyol with secondary hydroxyl groups and polyester polyol in specific ratios, creating a balanced formulation that achieves rapid cure rate while maintaining desirable flexibility, toughness, and overall mechanical properties
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 system enables the formation of polyurethanes with improved cure rates and balanced properties, allowing for a wider range of applications while maintaining desired toughness and weatherability.
Implementation Method 1
a zinc-containing catalyst, wherein the zinc-containing catalyst comprises at least one imidazole ligand and at least one carboxylate ligand
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A reaction system for forming a thermoset urethane or polyurethane comprising at least one polyol, at least one isocyanate, and a zinc-containing catalyst. In some aspects, the polyol may be a monomeric polyol comprising secondary hydroxyl groups or it may be a polymeric polyol comprising residues of the monomeric polyol. The zinc-containing catalyst may be effective for catalyzing the reaction of the polyol and isocyanate, particularly when at least a portion of the secondary hydroxyl groups in the monomeric or polymeric polyol are hindered secondary hydroxyl groups. Urethanes and polyurethanes formed as described herein may be used in coating compositions, including powder coating compositions, solvent-based coating compositions, and waterborne coating compositions, as well as in many other applications.