Crystalline Thermoplastic Polyurethane Hot-Melt Adhesive Composition
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Solution Overview
Problem
Conventional thermoplastic polyurethane (TPU) hot-melt adhesives have melting points in the range of 60-70 °C, exhibit long crystallization times, and lack sufficient heat and abrasion resistance, resilience, and faster processing times.
Innovation Solution
A crystalline thermoplastic polyurethane composition is developed, comprising a reaction product of a polyisocyanate component, polybutanediol succinate, optionally a chain extender, and optionally a catalyst, with a melting point of 80 °C to 130 °C and a recrystallization time of less than five minutes, enhancing heat resistance, abrasion resistance, and processing speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional TPU (polycaprolactone-based) is used as hot-melt adhesive, then the adhesive is easy to process and apply, but the melting point is low (60-70°C) resulting in poor heat resistance and long crystallization time (over 20 minutes)
Solution Approach 1:
The patent changes the chemical composition parameters of the TPU by using polybutanediol succinate instead of polycaprolactone as the polyol component, and by controlling the NCO/OH ratio (0.8-1.2) and molecular weight (3000-6000 Daltons), achieving a melting point of 80-130°C and crystallization time under 5 minutes
Solution Approach 2:
The patent creates a composite TPU system by combining polybutanediol succinate polyol with polyisocyanate, optionally adding chain extenders (1-10 phr) and catalysts (0.1-5 phr), achieving superior heat resistance and fast crystallization while maintaining adhesive properties
2Temperature
If conventional TPU composition is used, then the formulation is simple and cost-effective, but the heat resistance and abrasion resistance are insufficient
Solution Approach 1:
The patent elevates the melting point to 80-130°C through specific polyol selection (polybutanediol succinate with MW 3000-6000) and NCO/OH ratio control (0.8-1.2), providing heat resistance up to 100°C while maintaining manufacturability through standard polyurethane synthesis procedures
3Productivity
If conventional TPU is used as hot-melt adhesive, then the processing is straightforward, but the processing speed is slow due to long crystallization time
Solution Approach 1:
The patent achieves crystallization time under 5 minutes (compared to over 20 minutes for conventional TPU) by optimizing the polyol molecular weight (3000-6000 Daltons) and NCO/OH ratio (0.8-1.2), enabling faster production cycles and higher productivity
Solution Approach 2:
The patent uses catalysts (0.1-5 phr of tin compounds, zinc compounds, or organic compounds) as intermediaries to accelerate the crystallization process, reducing processing time while maintaining bond quality
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 provides superior heat resistance, abrasion resistance, resilience, and faster crystallization times compared to conventional TPU hot-melt adhesives, making it suitable for improved adhesive performance.
Implementation Method 1
The crystalline thermoplastic polyurethane comprises the reaction product of an isocyanate component, a polyol component, wherein the polyol component comprises polybutanediol succinate
Implementation Method 2
the crystalline thermoplastic polyurethane composition may have a melting point of 80 °C to 130 °C
Implementation Method 3
the crystalline thermoplastic polyurethane composition may have a recrystallization time after melting of less than five minutes
Data Source
AI summary
The disclosed technology relates to a crystalline thermoplastic polyurethane composition useful as a hot-melt adhesive, wherein the crystalline thermoplastic polyurethane in accordance with the present invention provides superior properties including higher melting point, heat resistance, abrasion resistance, resilience, and faster processing times.