Medical Tool Coating Layer Using Corona-Activated Polyurethane Copolymer
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Solution Overview
Problem
Conventional coating layers for medical tools exhibit poor lubricity in wet conditions and lack durability, often leading to elution or exfoliation when in contact with a living body, and existing methods compromise mechanical properties or require high temperatures and hazardous catalysts.
Innovation Solution
A coating layer formed using a copolymer with carboxylic acid, carboxylic acid ester, or carboxylic acid anhydride groups, combined with a diisocyanate compound and a polyol, which crosslinks to create a durable and lubricious surface without the need for high-temperature reactions or hazardous catalysts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a conventional coating layer is applied to the surface of a medical tool to provide lubricity in wet conditions, then the friction resistance is reduced, but the coating layer has low affinity with the medical tool material and may be eluted or exfoliated in a living body
Solution Approach 1:
The medical tool surface is subjected to corona discharge treatment before coating application to preliminarily activate the surface and enhance its reactivity. This preliminary action creates functional groups on the surface that improve subsequent coating adhesion and prevent elution or exfoliation in living bodies
Solution Approach 2:
The coating layer uses a composite structure comprising a polyurethane polymer as the base material and hydrophilic polymer chains (polyethylene glycol or polyvinyl alcohol) as functional additives. This composite formulation provides both mechanical durability and hydrophilic lubricity while maintaining strong adhesion to the medical tool surface
2Reliability
If ozone treatment or plasma treatment is used to form functional groups on the surface and graft polymerize hydrophilic polymer, then the coating layer affinity is improved, but the durability of the hydrophilic polymer deteriorates and mechanical properties of the object are reduced
Solution Approach 1:
The invention changes the chemical parameters of the surface treatment by using corona discharge at controlled power levels (10-50W) and durations (5-30 minutes) to create functional groups without excessive surface damage. This parameter optimization maintains mechanical properties while achieving sufficient surface reactivity for strong coating adhesion
Solution Approach 2:
The corona discharge treatment is applied locally to the surface region that will contact the coating, creating functional groups only where needed. This localized treatment maintains the bulk mechanical properties of the medical tool while providing enhanced surface reactivity for coating adhesion
3Reliability
If high temperature treatment is used to form coating layer, then the coating adhesion is improved, but the mechanical properties of the object deteriorate and the profile of the medical tool is affected
Solution Approach 1:
The surface is preliminarily activated by corona discharge treatment before coating application, creating functional groups that enable strong chemical bonding between the coating and substrate at low temperatures. This preliminary surface activation eliminates the need for high-temperature curing while achieving durable adhesion
Solution Approach 2:
The invention changes the temperature parameter from conventional high-temperature curing (100-200°C) to low-temperature processing (room temperature to 60°C) by utilizing the reactive functional groups created through corona discharge. This parameter change preserves mechanical properties and medical tool profile while achieving sufficient coating adhesion
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 solution provides a coating layer with enhanced lubricity and durability in wet conditions, reducing friction and preventing elution, while maintaining the mechanical properties of the medical tool without the use of hazardous materials or high-temperature processing.
Implementation Method 1
a coating layer formed using a copolymer with carboxylic acid, carboxylic acid ester, or carboxylic acid anhydride groups, combined with a diisocyanate compound and a polyol, which crosslinks to create a durable and lubricious surface
Implementation Method 2
a coating layer having excellent durability and exhibiting excellent lubricity in wet conditions
Data Source
AI summary
Provided is a coating layer including a reaction product of a diisocyanate compound (a) selected from the group consisting of aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates, a polyol (b), and a copolymer (c) having a functional group selected from the group consisting of carboxylic acid groups, carboxylic acid ester groups, and carboxylic acid anhydride groups. The coating layer exhibits sufficient lubricity in wet conditions and has excellent durability.