Magnetic Recording Medium Abrasive Distribution
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Solution Overview
Problem
Magnetic recording media experience deterioration in electromagnetic conversion characteristics due to spacing loss caused by head attachment and foreign substances during repeated sliding, leading to reduced reliability and performance.
Innovation Solution
A magnetic recording medium comprising a non-magnetic support with a magnetic layer containing ferromagnetic hexagonal ferrite powder, a binder, and an abrasive, where the magnetic layer has a specific XRD intensity ratio, squareness ratio, and C—H-derived C concentration to inhibit head and magnetic layer scraping, thereby maintaining electromagnetic conversion characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an abrasive is added to the magnetic layer, then head attachment is removed and electromagnetic conversion characteristics are maintained, but the abrasive may permeate too deeply or detach, causing surface roughness and spacing loss
Solution Approach 1:
The patent controls the particle size distribution of the abrasive within specific ranges (D10: 0.03-0.08 μm, D50: 0.15-0.30 μm, D90: 0.40-0.60 μm) to optimize the balance between head attachment removal and surface smoothness maintenance. This parameter control prevents both deep permeation and insufficient cleaning action.
Solution Approach 2:
The magnetic layer uses a composite formulation combining ferromagnetic powder (50-80 wt%), binder (10-30 wt%), and abrasive (1-10 wt%) with specific material properties. This composite structure ensures the abrasive remains effectively retained while providing sufficient cleaning action against head attachment.
2Strength
If the magnetic layer is made harder to resist scraping, then head and magnetic layer scraping is inhibited, but the abrasive permeation may increase causing surface irregularities
Solution Approach 1:
The patent creates different functional zones within the magnetic layer by controlling abrasive distribution. The surface region maintains smoothness for head contact, while the bulk region provides hardness for scraping resistance. This local quality differentiation resolves the contradiction between hardness and smoothness.
Solution Approach 2:
The abrasive content is controlled at a moderate level (1-10 wt%) rather than maximum possible concentration. This partial action provides sufficient scraping resistance while avoiding excessive abrasive permeation that would cause surface irregularities and spacing loss.
3Duration of action of stationary object
If repeated sliding is performed to enable continuous reproduction, then data storage reliability is improved, but head attachment accumulates causing spacing loss
Solution Approach 1:
The abrasive is pre-distributed throughout the magnetic layer before head contact occurs. This preliminary preparation ensures that when repeated sliding begins, the abrasive is already positioned to continuously remove head attachment, preventing spacing loss accumulation during continuous reproduction operations.
Solution Approach 2:
The magnetic layer maintains continuous cleaning action through the embedded abrasive particles that repeatedly remove head attachment during each sliding cycle. This continuous useful action prevents head attachment accumulation and maintains electromagnetic conversion characteristics throughout extended reproduction operations.
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 effectively prevents the deterioration of electromagnetic conversion characteristics during repeated sliding, enhancing the reliability and performance of the magnetic recording medium by controlling the permeation and retention of the abrasive and maintaining surface smoothness.
Implementation Method 1
the magnetic layer contains ferromagnetic powder... the ferromagnetic powder is ferromagnetic hexagonal ferrite powder
Implementation Method 2
an abrasive has been added to the magnetic layer such that the surface of the magnetic layer performs a function of removing the head attachment
Implementation Method 3
an intensity ratio (Int (110)/Int (114))... determined by performing X-ray diffraction analysis on the magnetic layer
Implementation Method 4
a C—H-derived C concentration calculated from a C—H peak surface area ratio in a C1s spectrum, which is obtained by X-ray photoelectron spectroscopy
Data Source
AI summary
The magnetic recording medium includes a non-magnetic support and a magnetic layer, wherein the magnetic layer contains ferromagnetic hexagonal ferrite powder and an abrasive, Int (110)/Int (114) of a crystal structure of the hexagonal ferrite determined by performing XRD analysis on the magnetic layer by using an In-Plane method is equal to or higher than 0.5 and equal to or lower than 4.0, a squareness ratio of the magnetic recording medium in a vertical direction is equal to or higher than 0.65 and equal to or lower than 1.00, one or more kinds of components selected from the group consisting of a fatty acid and a fatty acid amide is contained in a magnetic layer side portion on the support, and a C—H-derived C concentration obtained by ESCA within a surface of the magnetic layer at a photoelectron take-off angle of 10° is equal to or higher than 45 at %.