Patent ID: 8911597

Claim:
A method of preparing a double-layer antimicrobial coating, comprising the steps of: (1) placing a plastic substrate in a physical vapor deposition (PVD) vacuum equipment to carry out a vacuum process, and then rinsing and activating the substrate when a vacuum level reaches 10 −2 Pa to obtain an activated substrate; (2) coating a metal film on a surface of the activated substrate by vacuum coating; (3) spraying the substrate coated with the metal film with an antimicrobial intermediate coating, wherein the antimicrobial intermediate coating is added with an organic antimicrobial agent selected from the group consisting of 3-(trimethoxysilyl)propyldimethyloctadecylammonium, 10,10′oxybis-phenoxarsine, and phosphate complex; and (4) coating the substrate having the sprayed antimicrobial intermediate coating with an antimicrobial metal film by PVD to obtain a double-layer antimicrobial layer; wherein the antimicrobial metal film formed by PVD has a low density and includes a large number of bores, such that the antimicrobial agent of the antimicrobial intermediate coating can pass through the bores and move to a surface of the antimicrobial metal film, so as to kill the bacteria or suppress their growth.