Silylated Polyurethane Adhesive Solvent Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pressure-sensitive adhesives lack solvent resistance, making them unsuitable for applications exposed to aromatic and aliphatic solvents and oils in industries such as automotive, aerospace, and laboratory settings, where critical information and identification labels require protection.
Innovation Solution
A silylated polyurethane composition is developed, comprising a silylated polyurethane prepolymer derived from the reaction of hydroxyl-terminated polyester polyol and polyisocyanate, which is then silylated with silanes possessing hydrolyzable groups, creating a moisture-curable adhesive with enhanced adhesive and cohesive properties, including improved solvent resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional pressure-sensitive adhesives are used, then adhesive properties are sufficient for general applications, but solvent resistance is poor making them unsuitable for applications exposed to aromatic and aliphatic solvents and oils
Solution Approach 1:
The patent modifies the chemical structure of the adhesive by introducing silylated polyurethane prepolymers with specific molecular weight ranges (100-10,000) and controlled hydroxyl value (10-100 mg KOH/g). This parameter optimization enables the adhesive to achieve both sufficient adhesive properties and enhanced solvent resistance, resolving the contradiction between general applicability and solvent-exposed environment compatibility.
Solution Approach 2:
The patent creates a composite adhesive system combining silylated polyurethane prepolymers with specific additives and formulations. This composite approach allows the adhesive to simultaneously achieve good adhesive properties for general applications and resistance to aromatic and aliphatic solvents, thereby resolving the contradiction between versatility and solvent resistance.
2Strength
If adhesive compositions are formulated for good adhesive properties, then bonding performance is sufficient, but cohesive properties and solvent resistance are compromised
Solution Approach 1:
The patent optimizes the molecular weight and hydroxyl value parameters of the silylated polyurethane prepolymers to achieve a balance between adhesive bonding strength and cohesive stability. By controlling these parameters within specific ranges, the adhesive maintains strong bonding while resisting degradation in solvent environments.
Solution Approach 2:
The silylated polyurethane prepolymer acts as an intermediary material that bridges the requirements for strong adhesive bonding and cohesive stability. Its modified chemical structure allows it to provide both bonding capability and resistance to solvent-induced degradation, resolving the contradiction between these two properties.
3Reliability
If silylated polyurethane prepolymers with high molecular weight are used, then solvent resistance improves, but adhesive properties and processing characteristics deteriorate
Solution Approach 1:
The patent identifies and optimizes the molecular weight parameter of silylated polyurethane prepolymers to a specific range (100-10,000). This optimized parameter range achieves sufficient solvent resistance while maintaining acceptable processing characteristics, resolving the contradiction between solvent resistance and ease of processing.
Solution Approach 2:
The patent uses silylated polyurethane prepolymers with controlled, moderate molecular weights rather than excessively high molecular weights. This partial action approach provides adequate solvent resistance without the processing difficulties associated with very high molecular weight materials.
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 silylated polyurethane composition exhibits superior adhesive and cohesive properties, providing significant solvent resistance and maintaining performance in applications exposed to various solvents and oils, ensuring the integrity of labels and identification information.
Implementation Method 1
silylated with silanes possessing hydrolyzable groups, creating a moisture-curable adhesive
Data Source
AI summary
A silylated polyurethane composition containing polyester based polyurethane prepolymer. The silylated polyurethane composition when partially silylated is especially useful for pressure sensitive adhesives where it imparts superior adhesive and cohesive performance thereto.