Covalent Functional Compound Attachment to Ophthalmic Lenses
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Solution Overview
Problem
Existing methods for incorporating UV absorbing and wetting properties into contact lenses face challenges such as increased cure time due to UV absorber presence and leaching of UV moieties over time, leading to reduced UV absorbance.
Innovation Solution
A method involving contacting the lens with a functional compound capable of forming covalent bonds or undergoing oligomerization upon irradiation, followed by irradiation to attach or incorporate the compound, ensuring stable UV absorption without the need for additional photoinitiators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If UV absorbing agents are incorporated into the lens formulation, then UV absorbing properties are improved, but cure time increases
Solution Approach 1:
The patent extracts the UV absorbing agent from the lens formulation and applies it as a separate functional compound treatment after lens formation. This allows the lens to be cured without UV absorbing agents present, reducing cure time, while still achieving UV absorption through the subsequent functional compound application.
Solution Approach 2:
The lens is formed and cured first without UV absorbing agents, and then the UV absorption function is added in a preliminary functional compound treatment step. This preliminary action of forming the lens without interfering agents resolves the cure time issue while maintaining the ability to add UV protection afterward.
2Reliability
If UV absorbing agents are incorporated into the lens formulation, then UV absorbing properties are improved, but the agents leach from the lens over time
Solution Approach 1:
The UV absorbing function is extracted from the bulk lens material and implemented as a surface-functional compound treatment. This prevents the leaching issue because the functional compound is applied and cured on the lens surface rather than being mixed into the lens formulation where it would be subject to leaching over time.
Solution Approach 2:
The UV absorbing functional compound is applied locally to the lens surface rather than being distributed throughout the entire lens formulation. This local application ensures the UV absorbing agents remain concentrated where needed and do not leach from the bulk material, as they are固定在 the surface through covalent bonding or oligomerization.
3Reliability
If functional compounds are covalently attached to the lens, then UV absorbing capability is enhanced, but additional photoinitiators are required
Solution Approach 1:
The functional compound serves multiple functions: it provides UV absorption capability and simultaneously acts as its own photoinitiator system. This multi-functionality eliminates the need for separate photoinitiator additives, reducing device complexity while achieving both UV protection and covalent attachment to the lens.
Solution Approach 2:
The patent merges the UV absorbing agent and photoinitiator functions into a single functional compound. This compound contains both the UV absorbing moieties and the necessary photoinitiating groups, combining what would traditionally be separate components into one integrated substance that performs both functions.
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 method achieves enhanced UVB absorbing capability, with UVB transmittance significantly reduced, maintaining effectiveness even after extraction, thus addressing the issues of cure time and leaching.
Implementation Method 1
the functional compound comprises at least one group capable of forming a covalent bond with the lens upon exposing the lens to irradiation; and (b) irradiating the lens produced in step (a) to covalently attach the functional compound to the lens
Implementation Method 2
the functional compound comprises at least one group capable of undergoing oligomerization to produce an oligomer; and (b) irradiating and/or heating the lens produced in step (a) to produce the oligomer
Implementation Method 3
enhanced UVB absorbing capability, with UVB transmittance significantly reduced
Data Source
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AI summary
Described are methods for covalently attaching one or more functional compounds to an ophthalmic lens. The method involves (a) contacting the lens with a functional compound, wherein the functional compound comprises at least one group capable of forming a covalent bond with the lens upon exposing the lens to irradiation and/or heat; and (b) irradiating and/or heating the lens produced in step (a) to covalently attach the functional compound to the lens. Also described herein are ophthalmic lens produced by the methods described herein.