Polydimethylsiloxane Monomer with Phosphorylcholine for Contact Lenses
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Solution Overview
Problem
Contact lenses made with siloxane monomers exhibit high oxygen permeability but suffer from lipid adhesion due to hydrophobicity, leading to decreased wearing comfort, and existing methods like plasma treatment are costly and complex.
Innovation Solution
A polydimethylsiloxane-containing monomer with a phosphorylcholine group and a hydroxy group is developed, which enhances compatibility with hydrophilic monomers and polymers, resulting in a transparent polymerization product with anti-lipid adhesion properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a siloxane monomer is used as a raw material to improve oxygen permeability, then oxygen permeability is improved, but lipid adhesion occurs due to hydrophobicity leading to decreased wearing sensation
Solution Approach 1:
The patent changes the chemical parameters of the siloxane monomer by introducing hydrophilic groups (phosphorylcholine and hydroxyl groups) to modify the surface properties. This parameter change transforms the hydrophobic surface into a hydrophilic surface, preventing lipid adhesion while maintaining oxygen permeability through the siloxane backbone structure.
Solution Approach 2:
The patent creates a composite monomer structure combining hydrophobic siloxane groups (for oxygen permeability) with hydrophilic phosphorylcholine and hydroxyl groups (for anti-lipid adhesion). This composite structure at the molecular level integrates both functionalities into a single material that simultaneously achieves high oxygen permeability and resistance to lipid adhesion.
2Ease of operation
If a hydrophilic monomer is incorporated to improve wettability, then wettability is improved, but phase separation occurs due to poor compatibility with siloxane monomer resulting in difficulty producing transparent contact lens
Solution Approach 1:
The patent changes the compatibility parameters between siloxane and hydrophilic components by introducing hydroxyl groups onto the siloxane backbone. These hydroxyl groups form hydrogen bonds with hydrophilic monomers, significantly improving compatibility and preventing phase separation while maintaining transparency and wettability.
Solution Approach 2:
The hydroxyl groups on the siloxane monomer act as intermediary structures that bridge the hydrophobic siloxane backbone and hydrophilic monomers. This intermediary functionality facilitates compatible mixing and uniform distribution of components, preventing phase separation and ensuring lens transparency.
3Stability of the object's composition
If a large amount of hydrophilic group is introduced to achieve high compatibility with hydrophilic monomer and polymer, then compatibility is improved, but adverse influences on other elements required for excellent contact lens occur
Solution Approach 1:
The patent applies local quality by introducing hydrophilic groups (phosphorylcholine and hydroxyl) at specific locations on the siloxane monomer structure rather than throughout the entire polymer matrix. This localized modification achieves sufficient compatibility and anti-lipid adhesion properties without excessive hydrophilicity that would compromise mechanical strength and other essential lens properties.
Solution Approach 2:
The patent optimizes the quantity and type of hydrophilic groups introduced, balancing compatibility improvement with maintenance of mechanical properties. By selecting specific hydrophilic groups and controlling their concentration, the patent achieves high compatibility without adversely affecting other critical elements such as mechanical strength, oxygen permeability, and dimensional stability.
Data Source
AI summary
An object is to provide a polydimethylsiloxane-containing monomer that exhibits satisfactory compatibility with a hydrophilic monomer and a hydrophilic polymer, in which a polymerization product obtained by polymerizing a composition including the polydimethylsiloxane-containing monomer, the hydrophilic monomer, and the hydrophilic polymer has an anti-lipid adhesion property. It has been recognized that a polydimethylsiloxane-containing monomer having a phosphorylcholine group and a hydroxy group can achieve the object, and thus the present disclosure has been completed.