Thermoplastic Polyurethane Composite Adhesion
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Solution Overview
Problem
Existing composite elements comprising thermoplastics and polyisocyanate polyaddition products often experience undesirable detachment under mechanical loading, which is unacceptable in applications like automotive construction where mechanical stress is common.
Innovation Solution
The composite elements are formulated with a thermoplastic adjoined by a reaction product obtained from a mixture containing polyisocyanates, a first polyether polyol with a molecular weight of at least 6000 g/mol, and a polyester polyol with a functionality greater than 2 and specific hydroxyl number, along with additional components like 1,4-butanediol and diethylenetoluenediamine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polyisocyanate polyaddition products are used with thermoplastics, then the composite elements can be produced, but detachment occurs under mechanical loading
Solution Approach 1:
The patent changes the chemical parameters of the polyol components, specifically using a polyether polyol with molecular weight ≥6000 g/mol and a polyester polyol with functionality >2 and hydroxyl number 40-200 mg KOH/g. These parameter changes in the formulation create a polyisocyanate polyaddition product that maintains adhesion stability while achieving bond strength ≥26 N/50 mm under mechanical loading.
Solution Approach 2:
The patent creates a composite material system combining thermoplastic with a specifically formulated polyisocyanate polyaddition product containing multiple polyol components. This composite approach, where the polyurethane formulation itself is a composite of different polyols (polyether and polyester), resolves the contradiction by achieving both adhesion stability and high bond strength through material composition rather than relying on conventional single-component systems.
2Reliability
If lighter components are used in automotive construction, then resource consumption is reduced, but adhesion under mechanical stress becomes insufficient
Solution Approach 1:
The patent achieves the dual requirement of light weight and high adhesion strength by changing the molecular parameters of the polyol components. The polyether polyol with molecular weight ≥6000 g/mol provides lightweight properties, while the polyester polyol with functionality >2 and specific hydroxyl number ensures strong adhesion under mechanical stress, maintaining bond strength ≥26 N/50 mm.
3Manufacturing precision
If conventional polyol formulations are used, then production is simpler, but adhesion values remain below required thresholds
Solution Approach 1:
The patent achieves the required adhesion value of ≥26 N/50 mm by changing specific parameters of the polyol components: molecular weight of polyether polyol (≥6000 g/mol), functionality of polyester polyol (>2), and hydroxyl number (40-200 mg KOH/g). While the formulation becomes more complex with multiple polyol components, these parameter changes are straightforward to implement in production.
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
This formulation significantly enhances the adhesion between the thermoplastic and the polyisocyanate polyaddition product, maintaining integrity even under mechanical loading, and achieving adhesion values of at least 26 N/50 mm as measured by DIN 53357-A.
Implementation Method 1
a product of the reaction of a reaction mixture comprising i. an isocyanate component, comprising one or more polyisocyanates, and ii. an isocyanate-reactive component comprising ii.1) a first polyether polyol, ii.2) one or more polyester polyols
Data Source
AI summary
The invention relates to: composite elements comprising a thermoplastic material and a polyurethane adhering to said thermoplastic material; a method for producing same; and the use thereof.