PPS Bonded Magnet Resin Composition for Corrosive Gas Suppression

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Solution Overview

Problem

Existing bonded magnets using PPS resin suffer from increased mold maintenance, shortened mold life, and corrosive gas generation, which deteriorates mechanical properties and requires improved heat resistance and impact strength without compromising magnetic properties.

Innovation Solution

A resin composition for bonded magnets comprising a magnetic powder, PPS resin, and hydrotalcite powder, with specific weight percentages and surface treatments, to reduce corrosive gas generation while maintaining high mechanical and magnetic properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If PPS resin is used as binder resin to improve heat resistance and mechanical strength, then heat resistance and mechanical properties are improved, but corrosive gas generation increases and mold life is shortened

Engineering Contradiction:
Improveheat resistanceVSAvoidcorrosive gas generation
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

Hydrotalcite powder is introduced as an intermediary substance between PPS resin and the environment. It chemically absorbs corrosive gases (HCl, SO2) generated during high-temperature operation, preventing their release. The hydrotalcite acts as a mediator that captures harmful substances at their source, allowing PPS resin to maintain its heat resistance benefits while eliminating the corrosive gas problem.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention converts the harmful corrosive gases generated by PPS resin into a beneficial containment mechanism. By incorporating hydrotalcite powder, the corrosive substances that would normally damage molds and deteriorate the bonded magnet are instead absorbed and neutralized within the resin matrix, transforming a harmful byproduct into a controlled internal phenomenon.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Strength

If PPS resin is used to maintain mechanical strength at high temperature, then mechanical strength is improved, but mold maintenance frequency increases

Engineering Contradiction:
Improvemechanical strengthVSAvoidmold maintenance
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

Hydrotalcite powder serves as a protective intermediary that reduces the interaction between corrosive gases and the mold surface. By absorbing HCl and SO2 within the bonded magnet structure, it prevents these substances from attacking the mold, thereby reducing mold degradation and maintenance requirements while allowing PPS resin to maintain its high-temperature mechanical strength.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If hydrotalcite powder is added to reduce corrosive gas, then corrosive gas generation is reduced, but magnetic properties may deteriorate

Engineering Contradiction:
Improvecorrosive gas generationVSAvoidmagnetic properties
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The invention optimizes the concentration parameter of hydrotalcite powder within a specific range (0.1 to 25.0 wt% relative to PPS resin). By controlling this parameter, the patent achieves sufficient corrosive gas absorption capacity while maintaining magnetic properties. The optimized dosage ensures that hydrotalcite particles are dispersed without excessive aggregation that would interfere with magnetic powder alignment and magnetic performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The hydrotalcite powder is distributed locally throughout the PPS resin matrix to create zones of corrosive gas absorption. This local distribution strategy ensures that magnetic properties are preserved in regions dominated by magnetic powder and resin, while hydrotalcite-rich zones provide corrosive gas containment, achieving both goals simultaneously through spatial differentiation of functions.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS20250276909A1Resin composition for bonded magnets and molded body using same
Publication Date: 2025.09.04 TODA KOGYO CORP

AI summary

According to the present embodiment, there is provided a resin composition for bonded magnets which is excellent in physical properties such as heat resistance, bending strength, and IZOD impact strength without decreasing magnetic properties and which reduces generation of corrosive gas. There is provided: a resin composition for bonded magnets that includes a magnetic powder, a PPS resin, and a hydrotalcite powder, in which the content of the hydrotalcite powder is 0.1 to 25.0 wt % relative to the PPS resin; and a molded body of the resin composition for bonded magnets.