Polyisocyanate Component for Rigid Polyurethane Foam Insulation
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Solution Overview
Problem
Current rigid polyurethane foams face challenges in achieving enhanced insulation performance and mechanical properties, with existing formulations struggling to balance processability, friability, and thermal insulation effectively.
Innovation Solution
A polyisocyanate component comprising a preformed mixture of an aromatic oxazolidone and a polyisocyanate compound, with specific isocyanate functionality and viscosity characteristics, is used to create a polyurethane foaming system that improves the insulation and mechanical properties of rigid polyurethane foams, particularly suited for insulated metal panel fabrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional rigid polyurethane foam formulations are used, then basic insulation properties are achieved, but thermal insulation performance and mechanical properties cannot be simultaneously enhanced
Solution Approach 1:
The patent changes the chemical composition parameters of the polyisocyanate component by incorporating aromatic oxazolidone compounds with specific isocyanate functionality (1.8-6.0) and controlling viscosity (≤4.0 Pa-s at 25°C). This parameter optimization enables simultaneous improvement of thermal insulation performance and mechanical properties while maintaining processability.
Solution Approach 2:
The patent creates a composite polyisocyanate component by combining aromatic oxazolidone compounds with polyisocyanate compounds having specific functionality ranges. This composite approach allows the material to exhibit enhanced thermal insulation properties and mechanical toughness while maintaining adequate processability.
2Reliability
If polyisocyanate components with higher functionality are used, then insulation performance improves, but viscosity increases and processability deteriorates
Solution Approach 1:
The patent optimizes the viscosity parameter of the polyisocyanate component to ≤4.0 Pa-s at 25°C while maintaining isocyanate functionality between 1.8-6.0. This parameter control ensures that even high-functionality polyisocyanates remain processable, resolving the contradiction between insulation performance and ease of operation.
3Strength
If foam formulations with higher Isocyanate Index are used, then mechanical toughness improves, but friability increases
Solution Approach 1:
The patent changes the chemical structure parameters by incorporating aromatic oxazolidone groups that modify the foam matrix structure. This enables achieving higher Isocyanate Index (1.6-6.0) while maintaining low friability (≤10%), as the oxazolidone structure provides mechanical reinforcement without excessive crosslinking that would cause friability.
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 results in polyurethane foams with improved thermal insulation performance, reduced friability, and enhanced mechanical toughness, facilitating easier processing and higher Isocyanate Index applications, thereby addressing the limitations of existing rigid foam technologies.
Implementation Method 1
reacting a mixture of the above polyisocyanate component and a polyol component
Implementation Method 2
good thermal insulation performance (e.g., a K-factor of foam of no more than 20.5 mW/m-K at 10 °C)
Data Source
AI summary
A polyisocyanate component, a polyurethane foaming system, and an article made therefrom, wherein the polyisocyanate component includes (a) a preformed mixture including an aromatic oxazolidone compound that is the reaction product of at least one aromatic epoxide and at least one first polyisocyanate having an average isocyanate functionality of no more than 2.7 and greater than 1.8, in the presence of at least one catalyst, the aromatic oxazolidone compound includes at least one free isocyanate group and at least one aromatic oxazolidone group, the aromatic oxazolidone group includes an aromatic group and an oxazolidone group, and (b) at least one second polyisocyanate has an average isocyanate functionality equal to or greater than 2.7 and less than 6.0. The second polyisocyanate is added to the preformed mixture to form the polyisocyanate component. The polyisocyanate component has a viscosity of no more than 4.0 Pa-sat 25°C, an aromatic oxazolidone group content of 2 weight percent to 10 weight percent based on a total weight of the polyisocyanate component, and an average isocyanate functionality of from 1.8 to 6.0.