Epsilon Iron Oxide Magnetic Layer Contact Angle Control
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Solution Overview
Problem
Magnetic recording media using epsilon type iron oxide-based compounds experience a decrease in signal-to-noise ratio (SNR) due to increased friction and contamination when a magnetic head repeatedly slides on the magnetic layer, with existing solutions failing to effectively prevent this issue.
Innovation Solution
A magnetic recording medium comprising a non-magnetic support with a magnetic layer containing epsilon type iron oxide-based compound particles, a binding agent, and a specific contact angle range (30.0° to 45.0° with respect to 1-bromonaphthalene and 80.0° to 95.0° with respect to water), along with a manufacturing method involving heat treatment and alkali aqueous solution treatment to optimize particle properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a lubricant is added to the magnetic layer to decrease friction, then the amount of friction is reduced, but the lubricant is attached to the magnetic head causing contamination
Solution Approach 1:
The patent changes the surface properties of the magnetic layer by controlling the contact angle with 1-bromonaphthalene (30.0° to 45.0°) and water (80.0° to 95.0°), which optimizes the balance between friction reduction and preventing lubricant transfer to the magnetic head
Solution Approach 2:
The magnetic layer uses a composite structure combining epsilon type iron oxide-based compound particles with specific surface treatment, creating a material that inherently reduces friction while preventing lubricant contamination through its surface characteristics
2Force
If the contact angle with 1-bromonaphthalene is increased to prevent friction increase, then friction is reduced, but the contact angle range becomes difficult to control precisely
Solution Approach 1:
The patent specifies a precise contact angle range with 1-bromonaphthalene (30.0° to 45.0°) that balances friction reduction with manufacturing controllability, providing a clear target for production processes
Solution Approach 2:
The patent replaces direct mechanical lubrication with surface property control through contact angle optimization, substituting a mechanical approach (adding lubricant) with a surface chemistry approach that achieves friction reduction without lubricant transfer
3Strength
If epsilon type iron oxide-based compound is used as magnetic material, then high coercivity and nanosized particles are achieved, but signal to noise ratio decreases after repeated sliding
Solution Approach 1:
The patent creates a composite magnetic layer combining epsilon type iron oxide-based compound particles with specifically treated surface properties, achieving both high coercivity from the nanosized particles and reliable SNR performance through the optimized surface characteristics
Solution Approach 2:
The patent optimizes the surface parameters of the epsilon type iron oxide-based compound by controlling contact angles, which prevents the degradation of SNR that occurs with repeated sliding while maintaining the high coercivity properties
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 prevents a decrease in SNR after repeated sliding by reducing friction and contamination, maintaining the magnetic layer's integrity and performance.
Implementation Method 1
a contact angle measured regarding a surface of the magnetic layer is 30.0° to 45.0° with respect to 1-bromonaphthalene and 80.0° to 95.0° with respect to water
Data Source
AI summary
Provided are a magnetic recording medium including: a non-magnetic support; and a magnetic layer which is provided on at least one surface of the non-magnetic support and includes particles of epsilon type iron oxide-based compound, and a binding agent, in which a contact angle measured regarding a surface of the magnetic layer is equal to or greater than 30.0° and smaller than 45.0° with respect to 1-bromonaphthalene and 80.0° to 95.0° with respect to water, a manufacturing method of particles of an epsilon iron oxide-based compound, and a manufacturing method of a magnetic recording medium.