Polymer Layer Adhesion and Rubbing Resistance via Amide Concentration
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Solution Overview
Problem
Conventional optical members with polymer layers fail to achieve both high adhesion to substrates and rubbing resistance, as excessive amide content makes the polymer layer hard and less elastic, leading to poor recovery of projections after rubbing.
Innovation Solution
A polymer layer with an amide group concentration between 2 and 5 mmol/g and a minimum storage modulus of 1×10^8 Pa to 1×10^9 Pa at specific temperature ranges, ensuring both strong adhesion and sufficient elasticity for rubbing resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the polymer layer contains high amide group content to improve adhesion to substrate, then the adhesion strength increases, but the polymer layer becomes hard and less elastic, causing poor rubbing resistance
Solution Approach 1:
The patent applies parameter changes by precisely controlling the amide group concentration within the range of 2-5 mmol/g and the minimum storage modulus within 1×10^8-1×10^9 Pa. This optimized parameter range allows the polymer layer to maintain sufficient adhesion strength while preserving elasticity and rubbing resistance, resolving the contradiction between bonding strength and surface durability.
2Ease of operation
If the polymer layer is made harder to improve rubbing resistance, then the projection recovery improves, but the adhesion to substrate deteriorates
Solution Approach 1:
The patent resolves this contradiction by changing the physical parameters of the polymer layer through controlled amide group concentration (2-5 mmol/g) and storage modulus (1×10^8-1×10^9 Pa). This balanced parameter setting ensures the polymer is hard enough for rubbing resistance but remains adhesive enough for substrate bonding.
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 an optical member with both strong adhesion to the substrate and improved rubbing resistance, maintaining the antireflective moth-eye structure while preventing whitening due to projection loss.
Implementation Method 1
a polymer layer containing an amide group has high hydrogen-bonding strength and thus exhibits high adhesion to a substrate
Implementation Method 2
since amide groups (amide bonds) have high cohesion therebetween, the surface of the polymer layer opposite to the substrate was found to be less likely to have scratch marks
Implementation Method 3
This uneven structure has a continuously varying refractive index from the air layer to the substrate, thereby capable of reducing the reflected light significantly
Implementation Method 4
the polymer layer having a minimum storage modulus E′ of 1×10^8 Pa or higher and 1×10^9 Pa or lower at a bottom temperature of 110° C. or higher and 210° C. or lower in a dynamic viscoelasticity measurement
Data Source
AI summary
The optical member of the present invention includes a substrate and a polymer layer that is in direct contact with the substrate and includes on a surface thereof an uneven structure provided with multiple projections at a pitch not longer than a wavelength of visible light, the polymer layer containing an amide group, the polymer layer having an amide group concentration of 2 mmol/g or higher and lower than 5 mmol/g, the polymer layer having a minimum storage modulus E′ of 1×108 Pa or higher and 1×109 Pa or lower at a bottom temperature of 110° C. or higher and 210° C. or lower in a dynamic viscoelasticity measurement with a measurement temperature range of −50° C. to 250° C., a temperature rise rate of 5° C./min, and a frequency of 10 Hz.