Preparation And Properties Of UV Curable Conductive Ink

The development of science and technology means that the performance requirements of various electronic equipment are increasing.The research of conductive ink is very important for the development of electronics,military industry,communication and other fields.Silver based conductive ink is widely used.Although the conductive ink with single metal silver as filler has good conductivity,the cost of silver is high because of its high price.In addition,most of the conductive inks on the market are solidified by high temperature sintering,which also has the disadvantages of high cost and environmental pollution.UV curing technology has great application prospects in the field of conductive ink for its advantages of high efficiency and environmental friendliness.Therefore,the economic and environment-friendly conductive ink with silver coated or silver composite micro nano conductive powder as filler and UV light as curing method has attracted wide attention.The purpose of this thesis is to explore the preparation process of UV curable conductive ink with silver composite powder as conductive filler.Silver composite powder is prepared by chemical reduction or alcohol thermal method,and mixed with resin to prepare conductive ink.By changing the resin matrix type,solid content,filler ratio and curing process,the comprehensive performance of conductive ink was explored.The properties of powders and conductive ink coatings were characterized by optical microscope,scanning electron microscope（SEM）,X-ray diffraction（XRD）,laser particle size analysis,adhesion scratch tester and thermogravimetric analyzer（TG/DTG）.The mechanism of experimental phenomena was analyzed.Finally,the preparation process of conductive composite powders and conductive ink with good properties was determined.（1）The results show that the epoxy modified acrylic resin is used as the matrix,and the dendritic silver coated copper powder is used as the conductive filler,and the solid content is70wt%Ag@Cu Conductive ink.When the slurry viscosity is about 231Pa·s,the UV light distance is 3.5cm,the thickness is 0.12mm,and the light time is 150s,the surface of the conductive ink coating is smooth,without cracks,pinholes and other adverse phenomena.The adhesion between the ink and the substrate is greater than 20N,the resistivity is1.54×10^-6Ω·m,the electromagnetic shielding efficiency of the coating is 69d B,and the shielding efficiency can reach 99.9999%,The conductive ink prepared under high temperature has excellent comprehensive properties.（2）Ag coated Ti₃Si C₂ was prepared by chemical reduction method with silver nitrate as precursor and hydrazine hydrate as reducing agent（Ag@Ti₃Si C₂）The properties of the composite powder and its conductive ink were studied.The results show that when the silver content of composite powder is 70wt%,the average particle size is 32.66μm,and there is little agglomeration;when the solid content of ink is 95wt%,and the coating thickness is about 0.12mm,the average particle size of composite powder is 32.66μm,Ag@Ti₃Si C₂The surface of conductive ink coating is smooth and flat,without cracks and spikes,the resistivity is 4.20×10^-6Ω·cm,the adhesion is more than 20N,the electromagnetic shielding efficiency is up to 99.9999%,and the oil resistance is higher than 20N The ink coating has the best comprehensive performance.（3）Ag NWs/Ti₃Si C₂ composite powder with an average particle size of 1.57μm was synthesized by chemical reduction method and alcoholothermal method with silver nitrate as precursor,PVP as protective agent and ferric chloride as growth aid.The conductive ink was prepared by using the composite powder as conductive filler.The results show that when the mass ratio of Ag to Ti₃Si C₂ is 6.5:1 and the solid content is 90wt%,the surface of the ink coating is smooth and flat,and there is no fracture.The resistivity of the coating is5.52×10^-5Ω·cm,the adhesion force is greater than 30N,and the electromagnetic shielding efficiency can reach 99.999%.The comprehensive performance of the Ag NWs/Ti₃Si C₂conductive oil prepared under this process condition is the best.