Polyurethane Hot-Melt Adhesive Composition With Reduced Oligomer Blooming
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Solution Overview
Problem
Existing polyurethane adhesives face issues with cyclic oligomers causing blooming phenomena and mechanical property deterioration, and high melting temperatures leading to fabric damage, while there is a demand for eco-friendly materials with improved adhesive strength and flexibility.
Innovation Solution
A polyurethane resin composition using cyclic oligomer-removed polytrimethylene ether glycol, prepared by polymerizing 1,3-propanediol, distilling under controlled conditions to remove cyclic oligomers, and mixing with a chain extender and diisocyanate to achieve a bio-based adhesive with enhanced properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adhesive film is used for thermal bonding, then seamless bonding is achieved, but high melting point requires high temperature causing fabric damage
Solution Approach 1:
The patent modifies the chemical composition parameters of the polyurethane resin by incorporating specific soft segments (polyester polyol with 1,3-propanediol) and hard segments (diisocyanate and chain extender) in controlled ratios. This composition adjustment lowers the melting point from typical adhesive film temperatures (>100°C) to below 80°C, enabling low-temperature bonding that prevents fabric damage while maintaining seamless bonding quality
Solution Approach 2:
The patent creates a composite polyurethane resin system combining polyester polyol soft segments with diisocyanate hard segments and chain extenders. This composite structure achieves both low melting point (for fabric safety) and sufficient adhesive strength (for bonding reliability), resolving the contradiction between gentle processing and effective bonding
2Adaptability or versatility
If polyether-based polyurethane is used, then flexibility and elongation are improved, but adhesive strength and mechanical properties are reduced
Solution Approach 1:
The patent employs a composite polyurethane resin system combining polyester polyol (providing strength) with polyether polyol (providing flexibility). The synergistic interaction between these two polyol types creates a material that simultaneously achieves high adhesive strength and excellent flexibility/elongation properties
Solution Approach 2:
The patent optimizes the molecular weight parameters and hydroxyl value of the polyester polyol component, and adjusts the ratio of polyester polyol to polyether polyol in the composition. These parameter adjustments balance the mechanical strength contribution from polyester segments with the flexibility contribution from polyether segments
3Ease of manufacture
If cyclic oligomers are present in polytrimethylene ether glycol, then production is simplified, but blooming phenomenon and mechanical property deterioration occur
Solution Approach 1:
The patent removes cyclic oligomers from the polytrimethylene ether glycol through a combination of controlled polymerization conditions and post-purification steps. This extraction of harmful cyclic oligomers prevents blooming phenomenon and mechanical property deterioration, while the controlled polymerization process maintains production efficiency
Solution Approach 2:
The patent controls the polymerization parameters (temperature, time, catalyst amount) to minimize cyclic oligomer formation during synthesis. Additionally, the patent specifies molecular weight distribution parameters and purity requirements for the polytrimethylene ether glycol raw material to ensure low cyclic oligomer content in the final adhesive product
4Strength
If polyester-based polyols are used, then mechanical properties are improved, but low-temperature flexibility and hydrolysis resistance are reduced
Solution Approach 1:
The patent creates a composite polyol system combining polyester polyol (for mechanical strength) with polyether polyol (for low-temperature flexibility and hydrolysis resistance). This composite approach allows the adhesive to exhibit both high mechanical properties and excellent low-temperature performance
Solution Approach 2:
The patent adjusts the molecular weight and structural parameters of both polyester polyol and polyether polyol components, and optimizes their blending ratio. These parameter changes enable the composite system to achieve both high mechanical strength and superior low-temperature flexibility
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 improved adhesive strength, flexibility, and reduced blooming, with a bio-content of 25% or more, suitable for low-temperature bonding without fabric damage, addressing the limitations of existing adhesives.
Implementation Method 1
A polymerization method of PO3G is to react 1,3-PDO under an acid catalyst for a long time
Implementation Method 2
removing cyclic oligomers by distilling the product under conditions of a temperature of 100° C. to 250° C. and a pressure of 100.0 torr to 1.0 torr
Implementation Method 3
reacting a high-molecular-weight diol, such as polyester diols or polyether diols called polyols, with diisocyanate and a low-molecular-weight diol as a chain extender
Data Source
AI summary
Provided are a polyurethane resin composition for hot melt adhesives, in which cyclic oligomer-removed polytrimethylene ether glycol is used, and a preparation method thereof.