TPU Composition for Hydrolysis-Resistant Automotive Cable Sheaths
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thermoplastic polyurethanes fail to meet stringent requirements for automotive applications, particularly in temperature class D, due to insufficient high-temperature hydrolysis resistance and mechanical properties, and materials like ETFE and cross-linked polyolefins have limitations such as corrosiveness, complexity, and non-recyclability.
Innovation Solution
A thermoplastic polyurethane is produced by reacting a thermoplastic polyester with a diol to form a composition, which is then reacted with an isocyanate and a polycarbonate polyol, using specific molecular weights and catalysts to enhance mechanical and hydrolysis resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional thermoplastic polyurethanes are used, then good mechanical properties and high abrasion resistance are achieved, but high-temperature hydrolysis resistance and aging resistance are insufficient
Solution Approach 1:
The patent uses a composite polyol system combining polycarbonate polyol and polyester polyol in a specific ratio (60-90 wt% polycarbonate, 10-40 wt% polyester). This composite approach leverages the hydrolysis resistance of polycarbonate while maintaining the mechanical properties contributed by polyester, resolving the contradiction between durability and strength.
Solution Approach 2:
The patent specifies precise molecular weight ranges for both the polycarbonate polyol (1000-4000 g/mol) and polyester polyol (1000-3000 g/mol), as well as the polyisocyanate (1500-5000 g/mol). By optimizing these parameter ranges, the material achieves both improved hydrolysis resistance and maintained mechanical strength.
2Temperature
If ETFE is used for temperature class D applications, then high-temperature resistance is achieved, but corrosive gases are formed during fire
Solution Approach 1:
The patent modifies the chemical composition parameters by using a polycarbonate-polyester polyol blend with specific molecular weights and ratios. This chemical parameter change enables the material to achieve temperature class D resistance (150°C) while avoiding the formation of corrosive gases during combustion, unlike fluorinated materials such as ETFE.
3Temperature
If cross-linked polyolefin compounds are used, then temperature class D requirements are met, but production complexity and cost increase due to post-processing
Solution Approach 1:
The patent extracts the cross-linking step from the production process by using a thermoplastic polyurethane formulation that achieves temperature class D performance through its chemical composition (polycarbonate-polyester blend) rather than through post-processing cross-linking. This eliminates the need for irradiation or vulcanization equipment and steps.
Solution Approach 2:
The patent uses a thermoplastic formulation that can be processed and molded directly without requiring expensive post-processing cross-linking infrastructure. The material achieves its temperature resistance through its molecular structure and composition rather than through complex cross-linking, simplifying production.
4Duration of action of stationary object
If LV 112 hydrolysis resistance requirements are met with traditional materials, then service life is extended, but mechanical strength and elasticity are compromised
Solution Approach 1:
The patent employs a composite polyol system where polycarbonate polyol (60-90 wt%) provides hydrolysis resistance for extended service life, while polyester polyol (10-40 wt%) contributes to maintaining mechanical strength and elasticity. This composite approach allows simultaneous achievement of LV 112 hydrolysis resistance requirements and good mechanical properties.
Solution Approach 2:
The patent applies different functional qualities to different components of the polyol blend: polycarbonate polyol is optimized for hydrolysis resistance (local quality for durability), while polyester polyol is optimized for mechanical strength and elasticity (local quality for performance). This local quality differentiation allows the overall material to meet both service life and mechanical strength requirements.
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 exhibits improved mechanical properties and high-temperature hydrolysis resistance, suitable for automotive applications, and can be produced efficiently through continuous processes.
Implementation Method 1
Reaction of a thermoplastic polyester (PE-1) with a diol (D1) to obtain a composition (Z1) containing a polyester (PE-2)
Implementation Method 2
Reaction of the composition (Z1) obtained according to step (i) with an isocyanate composition (11) containing at least one polyisocyanate, and a polyol composition (P1)
Data Source
AI summary
The invention relates to thermoplastic polyurethanes obtainable or obtained by a method comprising the reaction of a thermoplastic polyester (PE-1) with a diol (D1) to obtain a composition (Z1) containing a polyester (PE-2) and the reaction of the composition (Z1) obtained in accordance with step (i) with an isocyanate composition (11) containing at least one polyisocyanate and with a polyol composition (P1), the polyol composition (P1) containing at least one polycarbonate polyol (PC1). The invention further relates to a method for producing the thermoplastic polyurethane. The invention further relates to a composition, containing a thermoplastic polyurethane according to the invention and at least one flame retardant. The invention additionally relates to the use of a thermoplastic polyurethane of this type to produce cable sheaths, films, molded parts, rolls, fibers, trim parts in automobiles, hoses, cable connectors, bellows, trailing cables, cable sheaths, seals, belts or damping elements containing a thermoplastic polyurethane of this type.