Halogen-Free Flame Retardant Thermoplastic Elastomer Composition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Halogen-containing materials like PVC are being replaced due to ecological and health concerns, but adding flame retardants to halogen-free thermoplastic elastomers often degrades their mechanical and physical properties, making it challenging to find suitable alternatives for wire and cable applications that require both flexibility and flame retardancy.
Innovation Solution
A composition comprising 12 wt% to 50 wt% thermoplastic elastomer with a Shore hardness less than 50D, 1 to 30 wt% ethylene vinyl acetate, and 48 wt% to 75 wt% of a flame retardant consisting of a metal hydrate and an oligomeric phosphate ester, with a weight ratio of metal hydrate to oligomeric phosphate ester greater than 1.45:1, is used to create a halogen-free flame retardant thermoplastic elastomer with improved mechanical and physical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flame retardants are added to thermoplastic elastomers, then flame retardancy is improved, but mechanical and physical properties deteriorate
Solution Approach 1:
The patent employs a composite flame retardant system combining metal hydrate (such as magnesium hydroxide or aluminum hydroxide) with oligomeric phosphate ester in a specific weight ratio greater than 1.45:1. This composite approach creates a synergistic effect where the metal hydrate provides flame inhibition through decomposition and the oligomeric phosphate ester enhances char formation and thermal stability, achieving effective flame retardancy while minimizing degradation of the thermoplastic elastomer's mechanical properties
Solution Approach 2:
The patent optimizes the weight ratio parameter of metal hydrate to oligomeric phosphate ester (maintaining it greater than 1.45:1) and controls the overall flame retardant content within 48-75 wt% of the composition. By precisely controlling these parameters, the patent achieves the optimal balance between flame retardancy and mechanical property retention, preventing excessive stiffening or strength loss that would occur with higher or unoptimized flame retardant loadings
2Object-affected harmful factors
If halogen-free materials are used to replace PVC, then ecological and health safety is improved, but flame retardancy is worsened
Solution Approach 1:
The patent converts the naturally low flame retardancy of halogen-free thermoplastic elastomers into an opportunity to implement an intumescent flame retardant system. The oligomeric phosphate ester promotes char formation that swells and insulates the material, while the metal hydrate decomposition provides additional flame inhibition. This approach achieves effective flame retardancy in halogen-free materials without requiring halogenated compounds, thus maintaining ecological and health safety while gaining fire resistance
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 composition achieves excellent flexibility with tensile elongation at break from 200% to 700% and passes stringent VW-1 and V-1 rating tests for wire and cable applications, ensuring strong flame retardancy while maintaining desirable mechanical properties.
Implementation Method 1
a flame retardant comprising a metal hydrate and an oligomeric phosphate ester
Implementation Method 2
an oligomeric phosphate ester, wherein the weight ratio of metal hydrate to oligomeric phosphate ester is greater than 1.45:1
Data Source
Figure 1
Figure 2
AI summary
The present disclosure provides a composition which includes a thermoplastic elastomer and a flame retardant composed of a metal hydrate and an oligomeric phosphate ester. The weight ratio of metal hydrate to oligomeric phosphate ester is greater than 1.45:1. The composition may be a component of an article such as a coated wire or a coated cable, with the composition present in the coating.