Polyolefin Adhesive Composition for Extended Open Time
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Solution Overview
Problem
Current adhesive compositions, particularly hot melt adhesives, face challenges in maintaining bonding performance at lower temperatures and have limited open time, making them less suitable for high-line-speed applications.
Innovation Solution
An adhesive composition comprising an olefin block copolymer with specific hard and soft block distributions, a tackifier, and an oil, which provides improved open time and bonding performance even at lower temperatures (100-120°C) by optimizing the molecular weight, crystallinity, and viscosity profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If hot melt adhesive is applied at lower temperatures (100-120°C), then energy consumption is reduced and substrate damage is minimized, but open time is shortened and bonding performance deteriorates
Solution Approach 1:
The patent modifies the chemical composition parameters of the adhesive by incorporating specific polyolefin copolymers with controlled comonomer content (3-15 mol%) and molecular weight (10,000-100,000 g/mol), along with tackifiers and oils in optimized ratios, to achieve lower melting points and extended open times at reduced application temperatures
Solution Approach 2:
The patent creates a composite adhesive system combining polyolefin copolymer base resin, tackifiers (rosin, terpene, or phenolic resins), and plasticizing oils to achieve synergistic effects that extend open time and maintain bonding performance at lower temperatures than conventional hot melt adhesives
2Productivity
If machine line speed is increased, then productivity is improved, but adhesive open time becomes insufficient for proper bonding
Solution Approach 1:
The patent adjusts the rheological parameters of the adhesive by selecting copolymers with specific molecular weights (10,000-100,000 g/mol) and comonomer contents (3-15 mol%), and optimizing the ratio of tackifier to base polymer, to achieve extended open times that match high-speed production requirements
Solution Approach 2:
The patent formulates the adhesive to exhibit dynamic viscoelastic properties that maintain adequate open time at rest but allow rapid setting under pressure, enabling synchronization with high-speed machinery cycles
3Strength
If conventional polymer-based hot melt adhesive is used, then adhesive strength is achieved, but open time is limited and high-line-speed applications are difficult
Solution Approach 1:
The patent develops a composite formulation combining polyolefin copolymers with controlled comonomer content (3-15 mol%), tackifiers (5-20 wt%), and plasticizing oils (5-20 wt%) to achieve both high adhesive strength and extended open time, overcoming the limitations of conventional single-polymer hot melt adhesives
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 achieves extended open time and enhanced bonding performance at lower temperatures, suitable for high-line-speed applications, with improved wetting and adhesion properties in nonwoven applications.
Implementation Method 1
Hot-melt adhesives at ambient temperature are generally solid materials that can be heated to a melt to hold adherents or substrates together upon cooling and solidifying
Implementation Method 2
An adhesive is a substance capable of holding solid materials (e.g., adherents or substrates) together by surface attachment
Data Source
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AI summary
The invention provides an adhesive formulation comprising an olefin block copolymer comprising hard blocks and soft blocks wherein the hard blocks comprise 4-8 mol% comonomer; and are present in an amount of 20 wt% - 45 wt%. This formulation is particularly advantageous for use in hot melt adhesives but may be used in other applications as well.