Hydrophilic Coating Formulation Using Norrish Type II Photoinitiators
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Medical devices require hydrophilic coatings that become lubricious upon wetting to minimize tissue damage and fluid drainage, but existing coatings face challenges with migratable components that can contaminate the body or environment, and have slow curing times, which affect their efficiency and safety.
Innovation Solution
A coating formulation comprising a hydrophilic polymer, polyelectrolyte, and Norrish Type II photoinitiators, such as substituted benzophenones, xanthones, or anthraquinones, with a high water content carrier liquid, which significantly improves curing speed and reduces migratable components, allowing for faster application and enhanced lubricity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional photoinitiators are used in hydrophilic coating formulations, then the coating can be cured to reduce migratable components, but the curing time is slow which reduces productivity
Solution Approach 1:
The patent changes the chemical parameters of the photoinitiator system by using Norrish Type II photoinitiators (such as benzophenone, xanthone, or anthraquinone derivatives) instead of conventional Type I photoinitiators. This parameter change in the photoinitiator type fundamentally alters the curing mechanism, enabling faster curing speeds while maintaining effective crosslinking to reduce migratable components.
Solution Approach 2:
The patent introduces a synergist as an intermediary substance that works together with the Norrish Type II photoinitiator to enhance the curing process. The synergist facilitates more efficient radical generation and propagation during photopolymerization, thereby accelerating the curing rate without compromising the coating's ability to reduce migratable components through proper crosslinking.
2Reliability
If the coating formulation is made with high water content to improve biocompatibility and reduce migratables, then the coating becomes more safe for medical applications, but the viscosity increases and application becomes more difficult
Solution Approach 1:
The patent adjusts the physical parameters of the coating formulation by optimizing the water content to a specific range (20-80 wt%) and compensating for the resulting viscosity changes through selection of appropriate carrier liquids and additives. This parameter optimization maintains high biocompatibility and safety while preserving adequate flow characteristics for easy application.
Solution Approach 2:
The patent creates a composite coating formulation that combines hydrophilic polymer, polyelectrolyte, Norrish Type II photoinitiator, synergist, and carrier liquid in specific proportions. This composite approach allows the formulation to achieve both high water content for safety and optimized viscosity for application through the synergistic interaction of multiple components.
3Reliability
If crosslinking is performed to eliminate migratable components, then the coating achieves firmness and reduced contaminates, but the curing process takes longer which affects production efficiency
Solution Approach 1:
The patent fundamentally changes the photopolymerization parameters by employing Norrish Type II photoinitiators that operate through a different mechanism than conventional initiators. This parameter change enables the crosslinking process to proceed at a faster rate while achieving the same firmness and contamination reduction, thereby reducing the time loss associated with curing.
Solution Approach 2:
The patent enhances the continuity and efficiency of the photopolymerization process through the use of Norrish Type II photoinitiators and synergists that maintain sustained radical generation throughout the curing process. This continuous and efficient action reduces the total curing time required to achieve firmness and migrate component reduction, improving production efficiency.
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 formulation results in a faster coating process with improved lubricity and reduced migratable components, enhancing the safety and efficiency of medical devices by minimizing tissue damage and environmental contamination.
Implementation Method 1
The term includes a treatment whereby the hydrophilic polymer crosslinks by a process called grafting wherein polymer chains are chemically connected under the influence of a reactive entity. This can, for instance, be performed by adding photoinitiators to a coating formulation, which subsequently are activated by electromagnetic radiation after a coating formulation is applied on a substrate.
Implementation Method 2
A type II photoinitiator induces crosslinking in case it is activated with electromagnetic radiation by hydrogen abstraction from a suitable synergist, which may be a low molecular weight compound or a polymer.
Data Source
AI summary
The invention is directed to a coating formulation for preparing a hydrophilic coating a hydrophilic polymer, a Norrish Type II photoinitiator, comprising a substituted benzohenone, xanthone, tioxanthone or anthraquinone, and more than 70 wt% of a carrier liquid; to a method of forming a hydrophilic coating on a substrate, the method comprising: applying a coating formulation to at least one surface of an article and allowing the coating formulation to cure for a time period less than 360 seconds; and to an article comprising at least one hydrophilic coating.