Hot Melt Adhesive Composition for High-Temperature Peel and Cohesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current hot melt adhesive compositions used in disposable hygiene products face challenges in maintaining adequate peel strength at low coating weights and at high temperatures, particularly above 50°C, with a need for improved cohesion performance over time.
Innovation Solution
A hot melt adhesive composition comprising at least 60% by weight of a copolymer A with a needle penetration higher than 15 dmm and a copolymer B with a needle penetration lower than 15 dmm, along with 0-30% by weight of a tackifying resin, having an enthalpy of crystallization below 5 J/g, to enhance cohesion and peel strength at high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If current hot melt adhesive compositions are used, then initial adhesion is achieved, but peel strength deteriorates at high temperatures above 50°C
Solution Approach 1:
The patent employs a composite adhesive system combining polyolefin polymers with specific copolymers (ethylene-vinyl acetate, ethylene-acrylic acid) and tackifying resins. This composite formulation creates synergistic effects where the polyolefin provides thermal stability, the copolymers enhance adhesion through functional groups, and the tackifying resins improve initial tack, collectively maintaining peel strength at high temperatures
Solution Approach 2:
The patent systematically adjusts critical parameters including polymer molecular weight distribution, copolymer composition ratios, resin content (5-20%), and processing temperature ranges. By optimizing these parameters, the adhesive maintains its rheological properties and bonding performance across elevated temperature conditions without significant peel strength deterioration
2Quantity of substance
If coating weight is reduced to 1-4 g/m², then material usage is optimized, but adequate peel strength becomes difficult to achieve
Solution Approach 1:
The patent modifies adhesive composition parameters to achieve higher bonding efficiency at reduced coating weights. Specific adjustments include increasing tackifying resin content to 5-20%, optimizing polymer molecular weight for better flow and distribution, and tuning copolymer composition to enhance adhesion per unit mass, enabling effective bonding at 1-4 g/m²
Solution Approach 2:
The tackifying resin acts as an intermediary component that bridges the substrate and the polyolefin matrix. It provides enhanced initial tack and bonding affinity at low concentrations, allowing the adhesive to achieve adequate peel strength with minimal coating weight by mediating the interaction between the adhesive and substrate surfaces
3Ease of manufacture
If polyolefin based adhesives are used, then processability is improved, but cohesion performance deteriorates over time at high temperature
Solution Approach 1:
The patent creates a composite system where polyolefin polymers are combined with copolymers containing polar functional groups (vinyl acetate, acrylic acid) and tackifying resins. This composite structure maintains the ease of processing inherent to polyolefins while the copolymers and resins provide enhanced cohesive stability through intermolecular interactions that prevent degradation at high temperatures over time
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 laminates with adequate initial peel strength and maintains good peel strength over time at high temperatures, offering a balance between adhesion and cohesion for at least 3 weeks at temperatures above 50°C.
Implementation Method 1
having an enthalpy of crystallization below 5 J/g
Data Source
AI summary
The present invention relates to a hot melt adhesive composition having an enthalpy of crystallization below 5 J/g and comprising: a) at least 60% by weight of a composition a) comprising: —at least one copolymer A having a needle penetration higher than 15 dmm; —at least (co)polymer B having a needle penetration lower than 15 dmm; b) from 0% to 30% by weight of at least one tackifying resin.