Polyurethaneurea Adhesive with Adjustable Bonding Force
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Solution Overview
Problem
Current self-adhesive materials for medical applications face challenges in achieving a balance between strong bonding and gentle removal without skin irritation, residue, and allergic reactions, with existing adhesives either being too strong or not providing sufficient bonding force for long-term medical use.
Innovation Solution
An amorphous polyurethaneurea adhesive is developed from an aqueous dispersion, combining specific polyurethaneurea components with adjustable bonding force, allowing for high adhesion while being removable without residue or skin irritation, and suitable for various medical and industrial applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If acrylate adhesives are used to achieve high bond strength, then bonding force is improved, but skin irritation and damage occur upon removal
Solution Approach 1:
The patent changes the chemical composition parameters by using polyurethaneurea instead of acrylate, and adjusts the bonding force through specific molecular weight ranges (10,000-100,000 g/mol) and composition ratios, achieving high bond strength without skin damage upon removal
Solution Approach 2:
The adhesive is formulated as a composite system containing polyurethaneurea (80-95 parts), hydrophilic polyisocyanate (5-20 parts), and optional additives, combining multiple components to achieve both high bonding strength and gentle removal properties
2Object-affected harmful factors
If silicone adhesives are used to achieve gentle removal, then skin compatibility is improved, but bonding force becomes insufficient
Solution Approach 1:
The patent changes the base adhesive material from silicone to polyurethaneurea with specific molecular weight (10,000-100,000 g/mol) and adds hydrophilic polyisocyanate to enhance bonding force while maintaining skin compatibility for gentle removal
3Strength
If existing adhesive systems are used to achieve sufficient bonding, then production complexity increases due to two-component mixing
Solution Approach 1:
The patent merges the polyurethaneurea adhesive and hydrophilic polyisocyanate crosslinking agent into a single aqueous dispersion formulation, eliminating the need for separate mixing of two components while maintaining sufficient bonding force through in-situ crosslinking
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 provides a high bonding force within a range of 0.3 N/20 mm to 25 N/20 mm, ensuring long-term wear without skin damage, residue, or allergic reactions, and is produced through a simple and cost-effective process, suitable for diverse applications including medical and wound care.
Implementation Method 1
the adhesive has good adhesion on the surface to be fixed
Data Source
AI summary
The present invention relates to an adhesive producible from an aqueous polyurethaneurea dispersion comprising an amorphous polyurethaneurea (V1) obtainable by reacting at leastA) one aliphatic, cycloaliphatic or araliphatic polyisocyanate component having an average isocyanate functionality of ≥1.8 and ≤2.6,B) one polyetherpolyol component,C) one amino-functional chain extender component having at least 2 isocyanate-reactive amino groups, containing at least one amino-functional compound C1) that does not have any ionic or ionogenic groups and/or an amino-functional compound C2) that has ionic or ionogenic groups,D) optionally further hydrophilizing components different than C2),E) optionally hydroxy-functional compounds having a molecular weight of 62 to 399 mol/g,F) optionally further polymeric polyols that are different than B),G) optionally one compound having exactly one isocyanate-reactive group or one compound having more than one isocyanate-reactive group, where only one of the isocyanate-reactive groups reacts with the isocyanate groups present in the reaction mixture under the reaction conditions chosen, andH) optionally one aliphatic, cycloaliphatic or araliphatic polyisocyanate component having an average isocyanate functionality of >2.6 and ≤4,where components B) and F) together contain ≤30% by weight of component F), based on the total mass of components B) and F) and a hydrophilic polyisocyanate (V2) preparable at least from the components ofI) an aliphatic, cycloaliphatic or araliphatic polyisocyanate component having an average isocyanate functionality of preferably ≥2.0 and ≤3.6,J) a polymeric, hydrophilic and monofunctional polyalkylene oxide component,K) optionally further hydrophilizing components different than J),L) optionally admixtures and auxiliaries.The invention likewise provides an adhesive layer and a product including the adhesive, a process for producing the adhesive layer, a specific polyurethaneurea, and the use of the adhesive and a kit having components (V1) and (V2).