Siloxane Macromer Contact Lens Composition for Oxygen Permeability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydrogel contact lenses face challenges with low water content, leading to reduced tension and toughness, and hydrophobic surfaces that are prone to bacterial growth and eye irritation, necessitating a composition that enhances hydrophilicity and oxygen permeability.
Innovation Solution
A composition for manufacturing contact lenses comprising a first siloxane macromer with cross-linking function, a second siloxane macromer, at least one hydrophilic monomer, and an initiator, which are mixed and treated thermally or with UV to form lenses with enhanced hydrophilicity and suitable water content, improving oxygen permeability and surface properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If hydrophilic monomer is added to improve water content, then water content increases, but tension and toughness decrease
Solution Approach 1:
The patent changes the molecular weight parameter of the siloxane macromer to a specific range (1,000 to 10,000) and controls the content of hydrophilic monomer (5-60 parts by weight) to optimize the balance between water content and mechanical strength, resolving the contradiction between improving water content and maintaining tension/toughness
Solution Approach 2:
The patent creates a composite material system combining siloxane macromer (providing oxygen permeability and structural integrity) with hydrophilic monomer (providing water content and comfort), where the synergistic combination allows achieving high water content while maintaining adequate mechanical strength through proper formulation
2Reliability
If silicone hydrogel material is used to improve oxygen permeability, then oxygen permeability increases, but hydrophobicity increases leading to bacterial growth and eye irritation
Solution Approach 1:
The patent applies local quality by incorporating hydrophilic functional groups (such as carboxyl, hydroxyl, or amine groups) at specific locations on the siloxane macromer structure, creating hydrophilic regions that locally counteract the hydrophobic silicone backbone, thereby reducing overall surface hydrophobicity while maintaining oxygen permeability
Solution Approach 2:
The patent changes the chemical composition parameters by selecting specific hydrophilic functional groups and controlling their content (5-60 parts by weight of hydrophilic monomer), transforming the surface properties from hydrophobic to hydrophilic, which prevents bacterial adhesion and reduces eye irritation while preserving the oxygen permeability benefits of silicone
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 contact lenses exhibit improved hydrophilicity, oxygen permeability exceeding 80, and water content between 30% to 60%, reducing bacterial growth and eye irritation while maintaining mechanical integrity.
Implementation Method 1
conducted by a thermal treatment or a UV irradiating treatment to form contact lenses
Implementation Method 2
the water content of the contact lenses can increase up to 80%
Data Source
AI summary
The method for manufacturing contact lenses includes the following steps. First, a first siloxane macromer, a second siloxane macromer, at least one hydrophilic monomer, an initiator and a solvent are mixed to form a mixture. Then the mixture is injected into a mold of contact lens and conducted by a thermal treatment or a UV irradiating treatment to form contact lenses. The number average molecular weight of the first siloxane macromer represented by the following formula (I), is 1,000 to 10,000 and the first siloxane macromer has a cross-linking function.The second siloxane macromer is selected from the group consisting of a siloxane macromer represented by the following formula (II) and a siloxane macromer represented by the following formula (III).Wherein in formula (II), p is an integer of 4 to 80, and in formula (III), q is an integer of 4 to 80 and r is an integer of 3 to 40.