PROCESS FOR MANUFACTURE OF NANOMETRIC, MONODISPERSE, AND STABLE METALLIC SILVER AND PRODUCT OBTAINED THEREFROM

• Main Authors: MARTINEZ CASTANON, GABRIEL ALEJANDRO, VAZQUEZ DURAN, ALMA GUADALUPE, RUIZ, FACUNDO, BOCANEGRA ROJAS, JOSE GERTRUDIS, MARTINEZ MARTINEZ, JESUS MANUEL, BENAVIDES PEREZ, RICARDO
• Format: Patent
• Language: English; French
• Published: 25.10.2016
• Subjects: CASTING; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; MAKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; METALLURGY; PERFORMING OPERATIONS; POWDER METALLURGY; PRETREATMENT OF RAW MATERIALS; PRODUCTION AND REFINING OF METALS; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WORKING METALLIC POWDER

The present invention relates to a procedure for preparation by a wet reduction method of nanometric particles of metallic silver, with diameter ranging from 1 to 100 nm and an average diameter of 20 to 40 nm, with monodispersion characteristics, stabilities exceeding 12 months and in a wide range of concentrations. The process comprises 4 stages: a) preparation of the reducing agent solution, taken from the tannins group and preferably tannic acid; b) preparation of a solution of soluble silver salts; c) reaction and, d) liquid-solid separation; the particle size is determined by the nature of the reducing agent and by the pH control of the currents. The final stage is designed for separating and concentrating the material after which the user can prepare the product for integration thereof in the desired medium. The particles obtained are redispersable in different media, such as water, alkidalic and phenolic resins, nitrocellulose, polyeurethane, vinylics, acrylics, alcohols, and in a wide range of organic and polymeric products such as high and low density polyethylene, Nylon, ABS and/or mixtures thereof.