PROCESS FOR PREPARING SILVER NANOPARTICLES OR SILVER NANOCOLLOID, AND THE COMPOSITIONS OF SILVER INK CONTAINING THE SILVER NANOPARTICLES

摘要

A preparation method of silver nanoparticles and silver nanocolloid and a silver ink composition comprising the product from the method are provided to obtain various forms of silver nanoparticle or silver nanocolloid as desired and to obtain ink composition which is calcined even at the temperature lower than 150deg.C for short time and forms highly conductive film or micro-pattern. A preparation method of silver nanoparticles and silver nanocolloid comprises steps of: a) reacting silver compound represented by a formula 1 of AgnX with at least one compound selected from a group consisting of ammonium carbamate based compounds represented by a formula 2, ammonium carbonate based compounds represented by a formula 3 and ammonium bicaronate based compounds represented by a formula 4 in order to prepare silver complex compound, wherein X is a substituent selected from oxygen, sulfur, halogen, cyano, cyanate, carbonate, nitrate, nitride, sulfate, phosphate, thiocyanate, chlorate, perchlorate, tetrafluoro borate, acetyl acetonate, carboxylate and derivative thereof; n is an integer of 1-4; and R1 to R6 are independently hydrogen, hydroxyl group, C1-C30 alkoxy group, C1-C30 aliphatic or alicyclic alkyl group, C6-C20 aryl or aralkyl group, C1-C30 alkyl or aryl group having substituted functional group, and heterocyclic compound and polymer and derivative thereof, R1-R6 contains heteroatom selected from N, S and O in the carbon chain, provided that R1-R6 are alkyl or aralkyl group having substituted or unsubstituted functional group, respectively, or R1 and R2 or R4 and R5 independently form a ring via alkylene optionally having heteroatom; and b) preparing silver nanoparticles by reacting the prepared silver complex compound with reducing agent or by subjecting the prepared silver complex compound in heat reduction or heat decomposition. For the preparation of silver nanocolloid, solvent and a colloid stabilizer are added to the prepared silver complex compound before reduction in step b). The heating temperature in the step b) is 40-200deg.C, and a heat decomposition promoter is optionally added for the reaction. A silver ink composition comprises the prepared silver nanoparticle produced by the method in the amount of 1-90% by weight in addition to an electric conductor, metal precursor or mixture thereof. The ink composition optionally comprises solvent, stabilizer, binder, surfactant, dispersant, coupling agent, wetting agent, thixotropic agent or leveling agent.