EMI Shielding Resin Composition Using Surface-Modified Carbon Nanotubes
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Solution Overview
Problem
Current resin compositions for electromagnetic interference (EMI) shielding face challenges in achieving high conductivity and uniform dispersion of carbon nanotubes, leading to inadequate EMI shielding performance and increased use of costly materials, while also compromising physical properties like hardness and surface roughness.
Innovation Solution
A resin composition incorporating carbon nanotubes surface-modified in subcritical or supercritical water without oxidants, combined with carbon compounds or metals, to enhance dispersibility and electroconductivity, allowing for the creation of a carbon hydride composite with improved EMI shielding effectiveness and reduced material costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large amount of conductive additive is added to achieve high electroconductivity, then EMI shielding performance is improved, but the hardness and surface roughness of the resin deteriorate
Solution Approach 1:
The patent changes the physical and chemical parameters of the carbon nanotubes by subjecting them to acid treatment (混酸处理) which modifies their surface properties. This treatment reduces the aspect ratio and improves dispersibility, allowing for lower loading amounts (0.1-15 parts by weight) while achieving the desired electroconductivity and EMI shielding performance without compromising the resin's mechanical properties
Solution Approach 2:
The patent creates a composite material system combining treated carbon nanotubes with resin and optional carbon compounds or metals. This composite approach allows the carbon nanotubes to form a conductive network at low concentrations, providing EMI shielding while maintaining the resin's structural integrity and surface properties
2Reliability
If carbon nanotubes are mixed to polymer through extrusion-ejection, then electroconductive composite is obtained, but carbon nanotubes are agglomerated or aligned due to shear stress resulting in defective dispersion
Solution Approach 1:
The patent applies preliminary acid treatment to the carbon nanotubes before mixing them with the polymer. This pre-treatment modifies the nanotube surface chemistry and reduces agglomeration tendencies, ensuring uniform dispersion throughout the polymer matrix during subsequent extrusion-ejection processes without requiring excessive shear stress
Solution Approach 2:
The acid treatment changes the surface parameters of carbon nanotubes by introducing functional groups and reducing bundling. This parameter modification enables the nanotubes to disperse uniformly in the polymer at low concentrations (0.1-15 parts by weight) without forming aggregates or aligning excessively during processing
3Reliability
If heavy metal materials are used for EMI shielding in electronic control units, then EMI shielding performance is achieved, but weight increases
Solution Approach 1:
The patent replaces expensive, heavy metal EMI shielding materials with a lightweight polymer composite containing small amounts of treated carbon nanotubes. This substitution achieves comparable or superior EMI shielding performance while dramatically reducing weight, making it ideal for automotive electronic control units where weight reduction is critical
Solution Approach 2:
The patent develops a lightweight composite material combining polymer matrix with treated carbon nanotubes and optional carbon compounds or metals. This composite provides effective EMI shielding through the conductive nanotube network while maintaining low density, replacing traditional heavy metal shielding materials in electronic control units
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 modified resin composition achieves excellent dispersibility, mechanical properties, and high conductivity, effectively reducing the need for heavy metals and enhancing EMI shielding performance, making it suitable for weight reduction in electronic control units and other applications.
Implementation Method 1
carbon nanotubes surface-modified in the subcritical water or supercritical water condition not using a separate oxidant
Implementation Method 2
carbon nanotubes surface-modified in the subcritical water or supercritical water condition not using a separate oxidant
Implementation Method 3
when the electromagnetic waves reach the conductor, eddy current is generated in the conductor due to electromagnetic induction, which reflects the electromagnetic waves
Implementation Method 4
eddy current is generated in the conductor due to electromagnetic induction, which reflects the electromagnetic waves
Data Source
Figure 1
AI summary
Provided is a resin composition for electromagnetic interference shielding. More particularly, provided is a resin composition having superior dispersibility and impact relaxation and high conductivity, the resin comprising: (a) 100 parts by weight of a resin; based on 100 parts by weight of the resin, (b) 0.1 to 15 parts by weight of a carbon nanotube surface-modified in a condition of the absence of oxidant; and (c) 1 to 40 parts by weight of a carbon compound, a metal, a metal compound, or a mixture thereof. The resin composition for electromagnetic interference shielding, comprising a carbon hydride composite, is specifically useful in an electronic control unit material for weight reduction of car, and thus can be replaced with a high-priced heavy metal material.