Vacuum deposition of Silicon oxide on the nylon 6 films utilizing silicon monooxide as an evaporation material

Silicon monoxide (SiO) amorphous layer was deposited on the biaxially oriented nylon 6 films in a vacuum evaporator. This deposited layer tightly attaches to the nylon film. SiO deposited nylon 6 films thus obtained are transparent and show a high barrier to the water vapor and oxgen. Wettability of the SiO surface of the film to the water, ink, and the adhesives are satisfactory for the gravure printing and lamination with polyolefin films. It was found that the gloss of nylon film, which reflects the surface roughness of the film, affects the uniformity of SiO deposited layer on the nylon film and barrier property of the deposited films. Permeabilities of the water vapor and oxygen through the SiO deposited nylon films were fairly high just after the deposition, especially when the deposited layer was thin, and then decreased to lower equilibrium values. These equilibrium values are surprisingly low comparing with other high barrier films such as nylon and polypropylene films coated with poly(vinylidene chloride). Further the SiO vacuum deposition was continuously carried out on the running nylon film. We found that the thickness of the silicon oxide layer on the nylon film and the water permeability are strongly related to the running velocity of the nylon film and the applied electric current to the heater.