Trans-Isomer Polyurethane Resin for Yellowing-Resistant Strength
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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 1,4-bis(isocyanatomethyl)cyclohexane containing 81% to 93% trans isomers, combined with an active hydrogen compound, including high-molecular-weight polyols and chain extenders, to enhance physical properties and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional polyisocyanates (aromatic or mixed isomers) are used, then production cost and ease of manufacture are improved, but yellowing resistance and mechanical properties deteriorate
Solution Approach 1:
The patent changes the isomer composition parameter of 1,4-bis(isocyanatomethyl)cyclohexane to contain 81% to 93% by mole of trans isomers. This specific parameter change resolves the contradiction by providing both excellent yellowing resistance and improved mechanical properties while maintaining manufacturability through established phosgenation processes.
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 yellowing resistance and mechanical properties while balancing manufacturing considerations.
2Strength
If trans-1,4-bis(isocyanatomethyl)cyclohexane with high trans isomer content (81%-93%) is used, then mechanical properties and yellowing resistance are improved, but manufacturing complexity increases
Solution Approach 1:
The patent specifies a precise parameter range of 81% to 93% trans isomer content in 1,4-bis(isocyanatomethyl)cyclohexane. This parameter optimization achieves the best balance between mechanical properties, yellowing resistance, and manufacturing feasibility, avoiding the need for overly complex separation processes while ensuring superior performance.
3Quantity of substance
If aromatic diisocyanates (TDI or MDI) are used, then production cost and availability are improved, but yellowing resistance deteriorates
Solution Approach 1:
The patent employs composite polyisocyanate formulations that may include aromatic diisocyanates (TDI, MDI) combined with alicyclic and aliphatic diisocyanates, particularly trans-1,4-bis(isocyanatomethyl)cyclohexane. This composite approach maintains cost-effectiveness and availability while achieving excellent yellowing resistance through the inclusion of UV-stable alicyclic and aliphatic components.
Solution Approach 2:
The patent applies local quality by using different types of polyisocyanates in specific regions or applications. Aromatic diisocyanates can be used in applications where yellowing is not critical, while alicyclic and aliphatic diisocyanates with high trans isomer content are used in applications requiring excellent yellowing resistance, optimizing both cost and performance.
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, yellowing resistance, and versatility for diverse applications such as elastomers, lenses, artificial leather, and foams, with enhanced thermal and chemical resistance.
Implementation Method 1
Polyurethane resins are usually produced by a reaction between a polyisocyanate component and a polyol component
Data Source
Figure 1
AI summary
Disclosed is a polyurethane resin which is obtained by a reaction between a polyisocyanate component, which contains 1,4-bis(isocyanatomehyl)cyclohexane including not less than 80% by mole of trans isomers, and an active hydrogen compound component.