Low Tack High Refractive Index Ophthalmic Copolymers
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Solution Overview
Problem
High refractive index acrylic materials used in intraocular lenses often exhibit tacky surfaces, making them difficult to handle and unfold, which is a challenge for their application in foldable intraocular lenses that require minimal surface adhesion.
Innovation Solution
Copolymerizing a composition comprising 50-93% of a specific polymerizable monomer and 5-20% of benzhydryl methacrylate with a polymerizable cross-linking agent, resulting in materials with low surface tack and high refractive indexes, allowing for flexible and transparent lenses that can be inserted through small incisions and recover their original shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If high refractive index acrylic materials are used in intraocular lenses, then the refractive index is improved, but surface tack increases making handling difficult
Solution Approach 1:
The patent applies parameter changes by systematically varying the composition ratios of monomers (aryl acrylic monomer, benzhydryl methacrylate) and cross-linking agents to achieve the optimal balance between refractive index and surface tack. The specification details multiple embodiments with different compositional parameters that produce materials with refractive indexes from 1.49 to 1.62 while maintaining low surface tack through controlled polymerization.
Solution Approach 2:
The patent employs composite materials by combining multiple monomer types (aryl acrylic monomer with specific structural parameters, benzhydryl methacrylate) and cross-linking agents in defined proportions. This composite approach allows the material to simultaneously achieve high refractive index through the aryl acrylic component while the benzhydryl methacrylate and cross-linking agent contribute to reducing surface tack and providing structural stability.
2Ease of operation
If surface treatments such as plasma gas treatments are applied to eliminate tack, then surface adhesion is reduced, but device complexity increases
Solution Approach 1:
The patent extracts the tack-reducing function from the post-manufacturing surface treatment stage and incorporates it directly into the material composition and polymerization process. By selecting specific monomer combinations and ratios (particularly benzhydryl methacrylate content at 5-20%), the low surface tack property is built into the base material itself, eliminating the need for additional plasma treatment steps.
Solution Approach 2:
The patent applies preliminary action by pre-configuring the monomer composition and polymerization conditions to produce materials with inherently low surface tack before any surface treatment is applied. The careful selection of cross-linking agents and their concentrations (typically 1-10% of total monomer weight) creates a material structure that resists surface adhesion from the outset, preventing the development of tack rather than treating it afterward.
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 resulting ophthalmic device materials exhibit reduced surface adhesion, enabling easier handling and insertion through small incisions while maintaining high refractive indexes and flexibility, ensuring effective deployment and functionality in intraocular lenses.
Implementation Method 1
The ophthalmic device materials are formed by copolymerizing a composition comprising 50-93% of a polymerizable monomer of structure (I) and 5-20% of a benzhydryl methacrylate monomer of structure (II) and a polymerizable cross-linking agent
Data Source
AI summary
High refractive index copolymers with reduced tack are disclosed. The copolymers, which are particularly suitable for use as ophthalmic device materials, comprise a benzhydryl methacrylate or benzydryl methacrylate derivative monomer.