Moisture-Curable Polyurethane Hot-Melt Resin Composition for Optical Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Moisture-curable polyurethane hot-melt adhesives lack sufficient waterproof properties and flexibility, leading to water intrusion and peeling issues when used in applications such as optical component bonding and building material lamination.
Innovation Solution
A moisture-curable polyurethane hot-melt resin composition is developed, comprising a urethane prepolymer formed from a reaction of a polyol blend containing polyether, crystalline polyester, amorphous polyester, and acrylic polyols with a polyisocyanate, optimizing melt viscosity, open time, and adhesion properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If an adhesive containing hot-melt adhesive composition resistant to moisture and heat is used, then adhesion is enabled even at low temperature, but waterproof performance is insufficient and water intrudes into the article in a relatively short time
Solution Approach 1:
The patent uses a composite polyol system comprising multiple types of polyols (polyester polyol, polyether polyol, acrylic polyol, and crystalline polyester polyol) in specific proportions to create an adhesive that achieves both low-temperature adhesion and waterproof performance. This composite approach allows the adhesive to combine the beneficial properties of different polyol types while mitigating their individual limitations.
Solution Approach 2:
The patent optimizes the composition ratios of different polyols and adjusts the NCO group content (1.0-5.0 mass%) to achieve the desired balance between waterproof performance and low-temperature adhesion. By carefully controlling these parameters, the adhesive achieves both waterproofness and adhesion capability at low temperatures.
2Reliability
If epoxy resin is used in the hot-melt adhesive composition, then resistance to moisture and heat is achieved, but flexibility is insufficient and peeling occurs when the article is dropped
Solution Approach 1:
The patent replaces epoxy resin with a composite polyol system that includes polyester polyol, polyether polyol, acrylic polyol, and crystalline polyester polyol. This composite polyol system provides both resistance to moisture and heat while maintaining flexibility and preventing peeling under drop impact conditions.
Solution Approach 2:
The patent controls the NCO group content within 1.0-5.0 mass% and optimizes the ratio of different polyols to achieve the right balance between resistance to moisture/heat and flexibility. This parameter optimization ensures the adhesive remains flexible and does not peel when dropped.
3Reliability
If the polyol blend ratio is optimized for waterproof properties, then water intrusion is prevented, but melt viscosity and open time become difficult to control
Solution Approach 1:
The patent specifies precise parameter ranges including NCO group content (1.0-5.0 mass%) and defined ratios of different polyols to achieve waterproof properties while maintaining manageable melt viscosity and open time. These controlled parameters ensure both waterproofness and ease of coating application.
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 exhibits enhanced waterproof properties, drop impact resistance, flexibility, and adhesion to various substrates, ensuring effective lamination and shape retention, suitable for optical and building material applications.
Implementation Method 1
a urethane prepolymer having an isocyanate group, the urethane prepolymer being produced through a reaction of a polyol (A) with a polyisocyanate (B)
Implementation Method 2
moisture-curable polyurethane hot-melt resin composition
Data Source
AI summary
It is an object of the present invention to provide a moisture-curable polyurethane hot-melt resin composition having excellent waterproof properties, drop impact resistance, and flexibility. The present invention provides a moisture-curable polyurethane hot-melt resin composition containing a urethane prepolymer having an isocyanate group, the urethane prepolymer being produced through a reaction of a polyol (A) with a polyisocyanate (B), wherein the polyol (A) contains a polyether polyol (A-1), a crystalline polyester polyol (A-2), an amorphous polyester polyol (A-3), and an acrylic polyol (A-4). The present invention also provides an adhesive containing such a composition and an article in which such a composition is used.