WHITE TIN COATED WITH POLYMER COATING, AND METHODS OF PRODUCTION THEREOF Russian patent published in 2016 - IPC B05D7/16 

FIELD: technological processes; metallurgy.

SUBSTANCE: invention relates to white tin, coated with polymer coating, and can be used for production of valve plates bottoms aerosol cans, detachable covers for cans, as well as deeply-drawn vessels and vacuum closing devices. Method of applying polymer coating chrome-less tinned surface tinned steel plate, first, during the first stage electrochemically are oxidized by Anodic polarization tinned steel plate in water and chrome-less electrolyte. On oxidized tinned surface during second stage polymer coating is applied by layering polymer film made from polymer material or by direct extrusion of molten polymer material. Polymer material is polyethylene terephthalate (pet), polypropylene (pp) or polyethylene (PE). Method of producing tin plate coated with polymer coating, involves electrolytic deposition of tin coating on one or both sides of the steel plate. That is followed by application of polymer coating on oxidized surface tin coating. White tin is coated with polymer coating of polymer material and is subjected to chrome-less passivation. Between the tin surface of the white tin and polymer coating there is only one thin layer of tin oxide and an optional layer adhesion booster. Tin oxide layer essentially consists of tetravalent oxide of tin and preferably has thickness not exceeding 0.1 mcm. Polymer material polymer coating is selected from a group comprising PET, PP or PE. Device for implementing the method of applying polymer coating on chrome-less surface or method of producing white tin includes transport device (8) for continuous transfer of continuous steel strip (10) in the direction of transportation. Device also includes device (7) for tinning for galvanic application of tin coating on steel tape (10), moved with speed through the device for application of coating. Device also includes device (8) for oxidation with electrolytic bath (8A), in which there is water chrome-less electrolyte. Through the electrolyte with certain rate of band motion passed tinned steel tape (10) for electrochemical oxidation of tin surface. Device also includes device (9) for application of polymer coating for single or double-sided application of polymer coating on tinned surface of steel tape (10) by means of layering polymer film made from polymer material or by direct extrusion of molten polymer material.

EFFECT: high corrosion resistance of white tin.

16 cl, 3 dwg