包覆型导电密封圈的制备与性能研究

Preparation and Performance Study of Cladded Conductive Sealing Ring

摘要: 以不同硬度的硅橡胶作为芯层材料，纯银粉填充硅橡胶作为外层包覆导电材料，设计并制备了包覆型结构导电密封圈。并测试了密封圈的导电性能、硬度、密度、力学性能、电磁屏蔽性能，分析了各项性能随芯层材料硬度的变化趋势。结果表明，与均质导电密封圈相比，包覆型导电密封圈具有较低的硬度和密度、较高的拉伸强度和可压缩性，但导电性能和电磁屏蔽性能有所降低，且降低幅度随着芯层材料硬度的降低而增大。当芯层材料硬度为50时，密封圈的硬度为57，拉伸强度为2.77 MPa，25%压缩力降低39.5%，体积电阻0.74 mΩ，屏蔽效能 ≥ 50 dB (200 kHz~18 GHz)，具有均衡的各项性能。

Abstract: A conductive sealing ring with a cladded structure was designed and prepared using silicone rubber with different hardness as the core material and pure silver powder-filled silicone rubber as the outer coating conductive material. The conductivity, hardness, density, mechanical properties, and electromagnetic shielding performance of the sealing ring were tested. The trend of various properties with the hardness of the core material was analyzed. The results show that compared with homogeneous conductive sealing rings, cladded conductive sealing rings have lower hardness and density, higher tensile strength and compressibility, but their conductivity and electromagnetic shielding performance are reduced, and the degree of decrease increases with the decrease in core material hardness. When the hardness of the core material is 50, the hardness of the sealing ring is 57, the tensile strength is 2.77 MPa, the 25% compression force is reduced by 39.5%, the volume resistance is 0.74 mΩ, the shielding efficiency is ≥ 50 dB (200 kHz~18 GHz), and it has balanced performance.