Preparation method of nano-silver of ink-jet conductive ink for polyimide substrate

The invention discloses a preparation method of nano-silver of ink-jet conductive ink for a polyimide substrate. According to the preparation method, nano-silver particles which are uniform and good in dispersion are prepared by adopting a liquid phase chemical reduction method and taking silver nitrate (AgNO3) as an oxidizing agent, sodium borohydride (NaBH4), glucose (C6H12O6) and sodium hydroxide (NaOH) as composite reducing agents and polyvinylpyrrolidone (PVP) as a dispersing agent. The particle sizes of the nano-silver particles prepared by the method are intensively distributed in a range of 40-70 nm. By adjusting parameters such as viscosity and surface tension, water-based conductive ink suitable for a piezoelectric ink-jet printer is prepared from self-made and purified nano-silver. A solvent system used by the ink is composed of ultrapure water and diethylene glycol (DEG), and the solid content of the ink is 20 wt%. Under the conditions that the viscosity of the ink is 2.5 mPa.s and the surface ten