Thermally Degradable Resin Composition for Low-Temperature Magnet Detachment
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Solution Overview
Problem
Existing methods for dismantling and recycling rare earth magnets from electric vehicle motors require manual operations and high-temperature heating, leading to increased costs and carbon emissions.
Innovation Solution
A resin composition with controlled adhesion strength and thermal expansion properties, allowing for easy dismantling at lower temperatures by heating, comprising a thermosetting resin, curing agents, and thermally expansible inorganic materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If high-temperature heating (600-700°C) is applied to ash the adhesive agent, then the magnet can be detached from the motor, but carbon dioxide is generated and environmental load increases
Solution Approach 1:
The patent changes the temperature parameter from high-temperature ashing (600-700°C) to low-temperature heating (80-150°C). The adhesive agent is designed to decompose and lose adhesion at this lower temperature range, allowing magnet detachment without generating significant CO2 emissions, thus resolving the contradiction between ease of manufacture and environmental harm
Solution Approach 2:
The adhesive agent undergoes a phase transition or chemical decomposition at low temperature (80-150°C), changing from a bonded state to a decomposed state that loses adhesion. This phase change enables magnet detachment without requiring high-temperature combustion, thereby reducing carbon dioxide generation while maintaining ease of manufacture
2Device complexity
If manual operations are used for magnet removal, then the process can be performed with simple equipment, but the recycling cost increases and productivity decreases
Solution Approach 1:
The patent replaces manual mechanical operations with a thermal field system. By applying heat to induce adhesive decomposition, the complex manual processes of heating, vibrating, and picking are substituted with automated heating and magnetic separation, improving productivity while keeping equipment relatively simple
Solution Approach 2:
The adhesive agent performs self-service by automatically decomposing and losing adhesion when heated to 80-150°C. This eliminates the need for complex mechanical intervention, allowing magnets to be easily separated through automated heating and magnetic attraction, thereby improving recycling efficiency without significantly increasing device complexity
3Strength
If strong adhesion is used for rotor fixation, then the structural integrity is improved, but the dismantlability and recyclability deteriorate
Solution Approach 1:
The patent creates a dynamic adhesion system where the adhesive strength changes with temperature. At operating temperatures, the adhesive provides strong bonding for structural integrity, but at dismantling temperatures (80-150°C), the adhesive decomposes and loses strength, enabling easy separation. This dynamic property resolves the contradiction between strength and dismantlability
Solution Approach 2:
The adhesive exhibits periodic behavior in terms of adhesion strength: strong during normal operation and weak during thermal processing. This periodic switching between bonded and separable states allows the system to maintain structural integrity during use while enabling easy dismantling for recycling, resolving the contradiction between strength and ease of manufacture
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
Facilitates efficient dismantling and recycling of motor components with reduced manual effort and carbon footprint, improving recyclability and resource utilization.
Implementation Method 1
a cured product of a resin composition used for rotor fixation or the like has a predetermined structure and also has predetermined physical properties
Data Source
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AI summary
An easily dismantlable resin composition according to the present invention contains a thermosetting resin, and an adhesion strength ratio (S2/S1) measured by the following procedure is 0.30 or less. [Procedure] The easily dismantlable resin composition is molded over a copper substrate under conditions of 175°C, 6.9 MPa, and 120 seconds and then subjected to post-curing at 175°C for 4 hours to obtain a test piece. An adhesion strength [N/mm2], which is obtained in a case where shearing adhesiveness to the copper substrate is measured at a rate of 300 µm/second at room temperature by using the test piece, is denoted as S1 [N/mm2]. Further, an adhesion strength [N/mm2] which is obtained in a case where the test piece is heated at 300°C for 30 minutes and then shearing adhesiveness to the copper substrate is measured at a rate of 300 µm/second at room temperature is denoted as S2 [N/mm2].