Polyurethane Hot Melt Adhesive for Thin Bond Lines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polyurethane hot melt adhesive compositions struggle to form thin bond lines for bezel-less electronic devices without compromising adhesion strength, curing time, and impact resistance.
Innovation Solution
A polyurethane hot melt adhesive composition comprising polyols, polyisocyanate, thermoplastic resin, and an aspect ratio promoter such as wax, talc, or calcium carbonate, in specific proportions, to achieve high aspect ratios and improved adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If adhesive composition is dispensed into thinner bond line for bezel-less design, then the overall bulk of the device is reduced, but the adhesion strength and bonding reliability deteriorate
Solution Approach 1:
The patent changes the chemical composition parameters of the adhesive by incorporating silane-modified polyurethane prepolymer and specific crosslinking agents, which enables the adhesive to achieve high strength in thin bond lines through moisture-cured crosslinking reaction
Solution Approach 2:
The patent creates a composite adhesive system combining silane-modified polyurethane prepolymer, crosslinking agents, and functional additives, which provides both thin bond line capability and high adhesion strength through synergistic effects of multiple components
2Volume of moving object
If adhesive composition is dispensed into thinner bond line for bezel-less design, then the overall bulk of the device is reduced, but the impact resistance deteriorates
Solution Approach 1:
The patent modifies the adhesive composition parameters by incorporating flexible chain extenders and impact modifiers alongside the crosslinking system, which provides toughness and impact resistance even in thin bond lines
Solution Approach 2:
The patent develops a composite adhesive formulation that integrates crosslinking agents for strength with flexible modifiers for impact resistance, achieving both thin bond line and high reliability through multi-functional component synergy
3Strength
If conventional adhesive compositions are used, then adhesion strength is maintained, but the bond line thickness cannot be reduced for bezel-less design
Solution Approach 1:
The patent changes the functional parameters of the adhesive by introducing moisture-cured crosslinking chemistry and silane modification, which enables the adhesive to cure effectively in thin layers while maintaining or enhancing adhesion strength
Solution Approach 2:
The patent replaces reliance on mechanical interlocking in thick bonds with chemical crosslinking mechanisms, allowing thin bond lines to achieve equivalent or superior strength through molecular-level bonding
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 adhesive composition enables thin bond lines with enhanced adhesion and bonding strength suitable for bezel-less electronic products, maintaining dispensability and impact resistance.
Implementation Method 1
reacting (A1) polyols comprising: (a) at least one polyester polyol, and (b) at least one polyether polyol, with (A2) at least one polyisocyanate having at least two isocyanate groups in one molecule
Implementation Method 2
it can further react with moisture to form crosslinking structure and achieve high final strength
Data Source
AI summary
The present invention provides a hotmelt adhesive composition, comprising (A) at least one polyurethane prepolymer obtained by reacting (A1) polyols comprising: (a) at least one polyester polyol, and (b) at least one polyether polyol, with (A2) at least one polyisocyanate having at least two isocyanate groups in one molecule; (B) at least one thermoplastic resin; and (C) at least one aspect ratio promoter in an amount of no more than 10% by weight based on the total weight of the composition.