METHOD FOR FORMATION OF PROTECTIVE COATING ON POLYMER SUBSTRATE

摘要

The invention relates to the field of the printing industry and can be used for fabrication of various products containing a holographic image, in particular, protective elements of securities, labels, promotional products, packing, etc. The purpose of the invention is improvement of the coating quality by virtue of its higher wear resistance and higher adhesion to the polymer substrate. The purpose is achieved by provision of the method for forming protective coating on polymer substrate comprising evaporation of zinc sulphide in vacuum followed by condensation thereof on the polymer substrate to the thickness of 50-500 nm, wherein the polymer substrate is first treated in oxygen plasma during 5-30 s, then chromium layer of 10-20 nm thickness is condensed thereon, and, after zinc sulphide condensation, a silicon dioxide layer with a thickness of 10-50 nm is additionally deposited; and wherein all layers are condensed in a single process cycle. The essence of the technical solution consists in formation of adhesive chemical bonds between the coating and the polymer substance, and in an increase in the coating hardness and chemical resistance.