Urethane Adhesive with Controlled Molecular Weight Dispersion
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Solution Overview
Problem
Conventional adhesives for protecting curved surfaces and electronic components during manufacturing and transportation are inadequate as they often damage the surfaces upon peeling and leave residues, and fail to maintain cleanliness during the process.
Innovation Solution
A urethane adhesive comprising a urethane prepolymer with a molecular-weight dispersion degree of 4 to 12, formed by reacting a polyol with a polyisocyanate at a specific molar ratio, which enhances adhesion, wettability, and removability while minimizing residues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional adhesives are used for protecting curved surfaces and electronic components, then adhesion strength is achieved, but surface damage occurs upon peeling and residues are left behind
Solution Approach 1:
The patent applies parameter changes by precisely controlling the molecular-weight dispersion degree (PDI) of the polyol component within the range of 1.05 to 2.5 and the NCO/OH molar ratio within 0.4 to 0.9. These parameter optimizations enable the adhesive to achieve strong bond strength while maintaining clean peeling without residues, resolving the contradiction between adhesion strength and surface damage prevention
Solution Approach 2:
The patent uses composite materials by combining polyol with specific molecular-weight distribution and polyisocyanate in controlled ratios, creating a urethane adhesive system that simultaneously provides strong adhesion and clean removability. The composite formulation allows the adhesive to bond strongly to curved surfaces while enabling residue-free peeling
2Strength
If adhesive strength is increased for better bonding, then adhesion improves, but peeling becomes difficult and may damage the surface
Solution Approach 1:
The patent resolves this contradiction through parameter changes by optimizing the molecular-weight dispersion degree and NCO/OH ratio to specific ranges. These controlled parameters enable the adhesive to achieve optimal bond strength while maintaining ease of peeling without surface damage, allowing the adhesive to be strong during bonding but easily removable when needed
3Reliability
If adhesive is used to protect optical parts during manufacturing, then protection is achieved, but contamination occurs during the process
Solution Approach 1:
The patent applies parameter changes by controlling the molecular-weight dispersion degree and NCO/OH ratio within specific ranges, which enables the adhesive to provide effective protection during manufacturing while minimizing contamination. The optimized parameters ensure the adhesive remains stable during storage and handling but can be cleanly removed without leaving contaminants on optical parts
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 excellent adhesion to curved surfaces, improved wettability, and easy removability with minimal residues, making it suitable for protecting sensitive components and surfaces during manufacturing and transportation processes.
Implementation Method 1
a urethane prepolymer (A), a polyfunctional polyol (B) and an isocyanate curing agent (C), and the urethane prepolymer (A) is a polymer having a molecular-weight dispersion degree of 4 to 12 which is obtained by reacting a hydroxyl group of a polyol (a) with an isocyanate group of a polyisocyanate (b)
Data Source
AI summary
An adhesive includes: a urethane prepolymer (A) obtained by reacting a polyol (a) with a polyisocyanate (b) under such conditions that the molar ratio of NCO/OH is 0.5-0.9 and having a molecular-weight dispersion degree [(weight-average molecular weight (Mw))/(number-average molecular weight (Mn)); hereinafter referred to also as Mw/Mn] of 4-12; a polyfunctional polyol (B), and an isocyanate curing agent (C).