High Functional Aromatic Polyester Polyols for Low Smoke Foams

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Solution Overview

Problem

Existing aromatic polyester polyols used in polyurethane foam production have low functionality and high viscosity, making them unsuitable for use as a sole source in foam manufacturing due to equipment limitations and requiring combination with polyether polyols, which increases smoke density.

Innovation Solution

Development of high functional aromatic polyester polyols with moderate viscosity and high aromatic content, allowing them to be used alone in polyurethane foam production without polyethers, achieving E-84 class one fire rating with minimal flame retardants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the functionality of aromatic polyester polyol is increased, then the polyol can be used as a sole source in foam production, but the viscosity increases making it unsuitable for equipment operation

Engineering Contradiction:
ImprovefunctionalityVSAvoidviscosity
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent changes the chemical structure parameters of the polyol by incorporating cyclic carbonate groups and specific molecular weight ranges (500-2000 g/mol) to achieve functionality greater than 2.8 while maintaining viscosity below 10,000 cps, resolving the contradiction between high functionality and acceptable viscosity for equipment operation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite molecular structure combining polyester backbone with cyclic carbonate groups and aromatic content (10-30%), producing a polyol that achieves both high functionality and moderate viscosity through synergistic structural composition

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If polyether polyols are combined with aromatic polyester polyols to reduce viscosity, then the mixture can be used in foam production, but the smoke density increases

Engineering Contradiction:
ImproveviscosityVSAvoidsmoke density
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and eliminates polyether polyols from the foam formulation by developing an aromatic polyester polyol with inherently low viscosity (below 10,000 cps) that does not require polyether additives, thereby removing the source of high smoke density while maintaining operational feasibility

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the potential harm of high viscosity into a benefit by designing a polyol with moderate viscosity that enables sole-polyol formulation, eliminating the need for polyether blends and consequently reducing smoke density in the final foam product

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 high functional aromatic polyester polyols enable the production of polyurethane foams with improved dimensional stability, compressive strength, and reduced smoke density, meeting commercial application requirements while minimizing the use of costly flame retardants.

Implementation Method 1

reacting an excess of an organic polyisocyanate with an etherified modified aromatic polyol

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Implementation Method 2

polyurethane foams made from such polyol-based compositions

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP2836534B1High functional polyester polyols
Publication Date: 2024.12.25 HUNTSMAN INTERNATIONAL LLC

AI summary

Aromatic polyester polyols with high functionality, moderate viscosity, and high aromatic content suitable as the sole polyol in the production of polyurethane foams without the use of any polyether polyols are disclosed. This unique combination of properties makes them suit for use as the sole polyol in the production of polyurethane foams. With reduction of flame retardants, these foams based on sole aromatic polyol can have E-84 class one fire properties. The aromatic polyester polyols of this invention are characterized as having a functionality of greater than 2.8 while having a moderate viscosity ranging from 4,000 -10,000 cps @ 25 C. A typical high functional polyester polyol of the present invention has a hydroxyl number in the range of 320-400, viscosity of 4,000 -10,000 cps @ 25 C, functionality of greater than 2.8 and percent phenyl content greater than 14.75.