Polyurethane Resin Composition for Strength and Yellowing Resistance
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Solution Overview
Problem
The production of polyurethane resins often faces challenges in achieving improved physical properties for various applications, particularly in terms of mechanical and yellowing resistance, which are not adequately addressed by existing formulations.
Innovation Solution
A polyurethane resin is developed using a polyisocyanate component with at least 80% by mole of trans isomers of 1,4-bis(isocyanatomethyl)cyclohexane, combined with an active hydrogen compound component having specific hydroxyl value and functionality, to enhance physical properties and application versatility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional polyisocyanate components (aromatic or standard aliphatic) are used, then yellowing resistance is achieved, but mechanical properties and physical performance are insufficient
Solution Approach 1:
The patent changes the isomeric composition parameter of 1,4-bis(isocyanatomethyl)cyclohexane to contain not less than 80% by mole of trans isomers. This specific parameter change simultaneously improves mechanical properties (tensile strength, elongation) and maintains excellent yellowing resistance, resolving the contradiction between strength and reliability.
Solution Approach 2:
The patent creates a composite polyisocyanate system by combining trans-1,4-bis(isocyanatomethyl)cyclohexane with other polyisocyanates (such as HDI, IPDI, or aromatic diisocyanates) in specific ratios. This composite approach allows optimization of both mechanical properties and yellowing resistance through synergistic effects of different isomers and polyisocyanate types.
2Strength
If polyisocyanate formulations are optimized for mechanical properties, then strength improves, but yellowing resistance deteriorates
Solution Approach 1:
The patent specifically controls the trans-isomer content parameter at not less than 80% by mole, which creates an optimal balance where mechanical properties are significantly improved while yellowing resistance is maintained. This precise parameter control resolves the contradiction by identifying the critical threshold that simultaneously satisfies both requirements.
Solution Approach 2:
The patent uses trans-1,4-bis(isocyanatomethyl)cyclohexane as a superior copy/alternative to conventional polyisocyanate mixtures, achieving both improved mechanical properties and maintained yellowing resistance through a single well-defined isomeric composition rather than complex formulations.
3Strength
If existing polyol components are used, then processing is simplified, but physical properties for various applications are insufficient
Solution Approach 1:
The patent optimizes the hydroxyl value parameter of polyol components to specific ranges (e.g., 20-120 mg KOH/g for certain applications, or 280-1240 mg KOH/g for others) and functionality parameters (e.g., 2-5). These parameter optimizations improve physical properties while maintaining formulation simplicity and ease of manufacture.
Solution Approach 2:
The patent selects different polyol parameters (hydroxyl value, functionality, molecular weight) tailored to specific application requirements - for example, lower hydroxyl values for applications requiring slower cure rates, or specific functionality ranges for achieving desired crosslink density. This localized optimization improves physical properties without requiring complex formulations.
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 resulting polyurethane resin exhibits improved mechanical properties and resistance to yellowing, making it suitable for a wide range of applications including elastomers, lenses, artificial leather, and foams.
Implementation Method 1
Polyurethane resins are usually produced by a reaction between a polyisocyanate component and a polyol component
Data Source
AI summary
Disclosed is a polyurethane resin which is obtained by a reaction between a polyisocyanate component, which contains 1,4-bis(isocyanatomethyl)cyclohexane including not less than 80% by mole of trans isomers, and an active hydrogen compound component.