Preparation And Properties Of Waterborne UV Curing Conductive Ink

The main advantages of electronic printing due to low cost,environmental protection,low temperature processing and mass production have attracted attention in various fields.The core problem of large-scale application is the development of conductive ink.Conductive inks with metallic nano-Ag particles have been studied,but the nanoparticles tend to condense and agglomerate during storage,while the sintering temperature is high.Graphene is used as a carrier to prepare modified composites due to its unique thin layer structure to improve the properties of the material.In this paper,nano-Ag-graphene composites were prepared by loading nano-Ag onto graphene sheets by reduction method,and used as conductive base materials to prepare water-based UV-curable high-performance conductive inks.The study is divided into three parts,first using isophorone diisocyanate（IPDI）,polycaprolactone diol（PCL-1000）,2,2-dimethylol butyric acid（DMBA）and pentaerythritol triacrylate（PETA）.The ester was prepared as a PUA intermediate,and then the resin was subjected to a capping reaction using epoxy acrylate（EA）to prepare an aqueous UV resin（WPE）.The properties of the prepared resin were characterized.The effects of n（NCO）/n（OH）value,PETA,DMBA,EA and photoinitiator on the properties of WPE emulsion and coating film were discussed.Secondly,AgNO₃ was used as the silver source.Vinylpyrrolidone（PVP）is used as a protective agent,and hydrated hydrazine is used as a reducing agent to prepare nano-Ag particles under different conditions.The effects of PVP content and AgNO₃ concentration on the morphology and particle size of nano-Ag were studied.At the same time,AgNO₃ and graphene oxide（GO）are combined and reduced to prepare nano-Ag-graphene dispersion（Ag-RGO）.Finally,Ag-RGO is added to WPE emulsion to prepare water-based UV-cured nano-Ag-graphite.The conductive ink was tested on the conductive ink,and the effect of curing time and composite content on the ink performance was investigated.This study draws the following conclusions:（1）The structure of WPE was characterized by Fourier transform infrared spectroscopy（FT-IR）.It can be seen that UV resin WPE was successfully prepared.Transmission electron microscopy（TEM）shows that WPE emulsion has uniform particle size and good stability.When studying the R value,when n（NCO）/n（OH）=1.6,the water absorption of the film is as low as 3.66%,the tensile strength is up to 26.41 MPa,and the elongation at break is at least 189.7%.At the time of the study,the best performance was obtained when W（C=C）was8.51%.The thermogravimetric curve shows that the higher the PETA content,the better the heat resistance of the resin,indicating that the increase in PETA content can improve the thermal stability.When the EA content is studied,the EA addition amount is 8%,the adhesion is 0,and the hardness is 2H,impact resistance 55 cm;when the photoinitiator content is studied,when the photoinitiator content is 3.75%,the curing speed is the fastest and the coating film has the best performance.（2）Four diffraction peaks appear in the nano-silver XRD spectrum,and the2θare 38.06^°,44.28^°,64.40^°and 77.60^°,respectively.The prepared nano-Ag is a face-centered cubic structure,which conforms to the Ag standard spectrum.The half-peak width of the diffraction peak is narrow and the intensity is high,indicating that the sample has a high degree of crystallization,no peak appears,and the prepared sample has high purity.According to the Scherrer formula,the crystal grain size can be calculated to be 31.9 nm.It can be seen from the Raman diagram that the G band of RGO is transferred from 1607 cm^-11 to 1600 cm^-1,and both XRD and UV spectra confirm that GO is reduced to RGO.It can be seen from the TGA diagram that after the reduction of GO to RGO,the molecular thermal stability is greatly enhanced and the molecular structure is more stable.In Ag-RGO,the nano-Ag has gaps filling the graphene,repairing structural defects,and making the heat of Ag-RGO The stability continued to increase and the final thermal decomposition remaining amount was 75.61 wt%.（3）By studying the effect of curing time on the performance of conductive ink,it can be known that when the photocuring time is 15 s,the ink resistivity can be as low as 7.97×10^-8Ω·m,and the resin is completely formed under the action of the initiator.The force is 0 and the hardness is H.By studying the influence of the composition of the conductive base on the performance,as the proportion of nano-Ag-graphene in the conductive base of the ink increases,the resistivity decreases greatly.When the ratio is 1:1,the lowest is 7.2×10^-8Ω·m,does not have much influence on adhesion and hardness.