CHROMIUM-CHROMIUM OXIDE COATINGS APPLIED TO STEEL SUBSTRATES FOR PACKAGING APPLICATIONS AND METHOD FOR PRODUCING SAID COATINGS Russian patent published in 2018 - IPC C25D3/06 C25D5/48 C25D11/38 

FIELD: electrolytic methods.

SUBSTANCE: invention relates to electroplating and can be used for packaging applications. Method comprises electrolytically depositing on said substrate said chromium metal - chromium oxide coating in a single process step from an electrolyte comprising basic chromium sulphate, a chelating agent and a conductivity increasing salt, wherein the cation in the chelating agent and the conductivity increasing salt is an alkali metal cation, the chelating agent contains an anion of formic acid, and to ensure chromium deposition, the threshold density of the cathode current is exceeded to reach a predetermined pH at the substrate surface which is higher than the pH in the electrolyte volume. Resulting substrate is further provided with a thermoplastic monolayer or multilayer polymer coating comprising thermoplastics such as polyesters or polyolefins, acrylic resins, polyamides, polyvinyl chloride, fluorocarbon polymers, polycarbonates, styrene resins, ABS plastics, chlorinated polyethers, ionomers, urethane resins and functionalised polymers, and / or copolymers thereof and / or mixtures thereof.

EFFECT: technical result: the creation of a substrate, not associated with the use of Cr (VI) during its production.

20 cl, 7 tbl, 5 dwg