Preparation method of low-temperature polyurethane-based conductive silver paste

The invention discloses a preparation method of low-temperature polyurethane-based conductive silver paste, and belongs to the technical field of low-temperature conductive silver paste preparation. The method comprises the steps of mixing silver nitrate with polyvinylpyrrolidone evenly, reducing silver ions by using ferrous sulfate and carrying out washing and drying to prepare superfine silver powder for later use; preparing a pre-polymerization product by employing polyether glycol and diisocyanate as raw materials and closing the pre-polymerization product by using methyl ethyl ketoxime to prepare a polyurethane-based prepolymer; finally stirring and mixing the polyurethane-based prepolymer, spare superfine silver powder and DBE and preparing the low-temperature polyurethane-based conductive silver paste through grinding and dispersing treatment. According to the preparation method, the preparation steps are simple; the obtained low-temperature conductive silver paste is good in sintering property and has