Aromatic Polyamide Magnetic Recording Medium Back Coating Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Magnetic recording media with aromatic polyamide supports experience stability issues when exposed to temperature changes from low to high under high humidity conditions, leading to deterioration in running stability due to increased moisture absorption and friction coefficients.

Innovation Solution

A magnetic recording medium with an aromatic polyamide support, a magnetic layer, and a back coating layer, where the spacing difference measured by optical interferometry after methyl ethyl ketone cleaning is between 0 nm and 30.0 nm, and the support has a moisture absorption of 2.2% or less, to stabilize the medium's running stability in varying temperature and humidity environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the magnetic recording medium is stored in a high temperature and high humidity environment after a temperature change from low temperature to high temperature under high humidity, then the moisture absorption of the aromatic polyamide support increases, but the running stability deteriorates

Engineering Contradiction:
Improverunning stabilityVSAvoidmoisture absorption
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the physical and chemical parameters of the back coating layer by controlling the spacing difference (Safter−Sbefore) to be greater than 0 nm and equal to or smaller than 30.0 nm, and by selecting specific non-magnetic powder materials. This parameter optimization prevents excessive moisture absorption by the aromatic polyamide support in high temperature and high humidity environments, thereby maintaining running stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The back coating layer acts as an intermediary between the aromatic polyamide support and the high temperature and high humidity environment. By optimizing the back coating layer's properties (spacing difference and non-magnetic powder content), it mediates the interaction between moisture and the support, preventing direct harmful effects on the magnetic recording medium's running stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the spacing difference (Safter−Sbefore) of the back coating layer is increased to prevent moisture absorption, then the running stability is improved, but the manufacturing precision requirement becomes more stringent

Engineering Contradiction:
Improverunning stabilityVSAvoidspacing control precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The invention defines a specific range for the spacing difference (Safter−Sbefore) greater than 0 nm and equal to or smaller than 30.0 nm, which balances the need for preventing moisture absorption with the practical constraints of manufacturing precision. This parameter range ensures running stability while being achievable through conventional manufacturing processes.

Inventive Principle:
Principle #35Parameter changes

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 deterioration in running stability by reducing moisture absorption and friction, ensuring stable performance even in high temperature and high humidity environments.

Implementation Method 1

a difference (Safter−Sbefore) between a spacing Safter measured by optical interferometry regarding a surface of the back coating layer after methyl ethyl ketone cleaning and a spacing Sbefore measured by optical interferometry regarding the surface of the back coating layer before methyl ethyl ketone cleaning is greater than 0 nm and equal to or smaller than 30.0 nm

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

a back coating layer including a non-magnetic powder on the other surface of the non-magnetic support

Methodology Applied
Scientific EffectPhysical barrier:

Implementation Method 3

a spacing Safter measured by optical interferometry regarding a surface of the back coating layer

Methodology Applied
Scientific EffectOptical interferometry: Interference

Data Source

PatentUS11189318B2Magnetic recording medium and magnetic recording and reproducing device
Publication Date: 2021.11.30 FUJIFILM CORP

AI summary

The magnetic recording medium includes a non-magnetic support, a magnetic layer including a ferromagnetic powder on one surface of the non-magnetic support, and a back coating layer including a non-magnetic powder on the other surface of the non-magnetic support, in which a difference (Safter−Sbefore) between a spacing Safter measured by optical interferometry regarding a surface of the back coating layer after methyl ethyl ketone cleaning and a spacing Sbefore measured by optical interferometry regarding the surface of the back coating layer before methyl ethyl ketone cleaning is greater than 0 nm and equal to or smaller than 30.0 nm, and the non-magnetic support is an aromatic polyamide support having a moisture absorption of 2.2% or less.