UV-Curable Coating Composition Resolving Picture Frame Effect
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Solution Overview
Problem
Current UV-curable coating compositions for consumer electronics often exhibit 'picture frame' effects due to high flowability, leading to unacceptable leveling properties and mirror surface finishes, despite attempts to increase molecular weight or reduce volatility of diluents.
Innovation Solution
A coating composition comprising functional urethane acrylate, photoinitiator, organic solvent, and modified functional urethane acrylate, applied to a plastic substrate with controlled thickness and UV-cured, achieving balanced flowability and excellent gloss properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the molecular weight of the main resin is increased to decrease flowability, then the picture frame effect is reduced, but the leveling property of the coat film becomes unacceptable
Solution Approach 1:
The patent changes the molecular weight parameter of the resin by introducing a specific low molecular weight polyol (1,3-propanediol) into the polyurethane acrylate synthesis. This creates a resin with controlled flow properties that prevents picture frame effect while maintaining acceptable leveling, resolving the contradiction between reducing flowability and preserving leveling property
Solution Approach 2:
The patent creates a composite resin system by combining polyurethane acrylate with a specific low molecular weight polyol modifier. This composite material achieves the desired balance between flow control and leveling performance, solving the technical contradiction through material composition optimization
2Object-generated harmful factors
If highly volatile diluents are used to decrease flowability of wet films, then the picture frame effect is decreased, but the mirror surface effect and gloss property deteriorate
Solution Approach 1:
The patent modifies the resin's molecular weight and structural parameters through controlled synthesis with specific polyols, achieving appropriate flowability without relying on highly volatile diluents. This maintains the mirror surface effect and gloss properties while still preventing picture frame effect
3Ease of operation
If the coating has high flowability for easy application, then the coating process is easier, but the picture frame effect occurs with poor leveling
Solution Approach 1:
The patent optimizes the resin's molecular weight and viscosity parameters by incorporating low molecular weight polyol modifiers, creating a coating composition with balanced flow characteristics that enables easy application while preventing picture frame effect and maintaining good leveling
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 solution provides a coating with excellent leveling properties and mirror surface effects, maintaining a gloss reading of greater than or equal to 80° while effectively controlling rheology, thus addressing the 'picture frame' issue and ensuring high-quality surface finishes.
Implementation Method 1
UV radiating the coating composition at a strength and time to effect cure
Data Source
AI summary
Disclosed is a coating composition comprising: (a) a functional urethane acrylate; (b) a photoinitiator; (c) an organic solvent; and (d) a modified functional urethane acrylate, and the method for applying said coating composition. The disclosed coating composition may have both excellent rheology properties and excellent gloss properties in the resulting film.