Global Patent Index - EP 3626862 A1

EP 3626862 A1 20200325 - PASSIVATION PROCESS OF A STEEL TINPLATE

Title (en)

PASSIVATION PROCESS OF A STEEL TINPLATE

Title (de)

PASSIVIERUNGSVERFAHREN EINER STAHLZINNPLATTE

Title (fr)

PROCÉDÉ DE PASSIVATION DE FER BLANC D'ACIER

Publication

EP 3626862 A1 20200325 (EN)

Application

EP 19198876 A 20190923

Priority

IT 201800008861 A 20180924

Abstract (en)

The present invention concerns a Cr-free passivation process of a tinplate comprising the following steps in sequence:a. subjecting said tinplate to at least one cathodic electrolytic treatment in an aqueous solution containing at least one sulphate of an alkali metal to obtain a tin oxide surface layer having thickness lower than 6 mC/cm<sup>2</sup>;b. subjecting said tinplate to at least one cathodic electrolytic treatment in an aqueous solution containing at least sulphate ions and zirconium ions to form a passivation layer containing zirconium on said tin oxide surface layer.The process allows obtaining passivated tinplates on which the coatings, such as enamels, paints and polymeric films, adhere well, without using chromium-containing compounds.

IPC 8 full level

C25D 5/48 (2006.01); C25D 9/08 (2006.01); C25D 7/06 (2006.01)

CPC (source: CN EP)

B05D 3/14 (2013.01 - CN); C25D 5/48 (2013.01 - EP); C25D 9/04 (2013.01 - CN); C25D 9/08 (2013.01 - EP); C25F 5/00 (2013.01 - CN); B05D 2350/60 (2013.01 - CN); C25D 7/0614 (2013.01 - EP)

Citation (applicant)

Citation (search report)

Designated contracting state (EPC)

AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

Designated extension state (EPC)

BA ME

DOCDB simple family (publication)

EP 3626862 A1 20200325; EP 3626862 B1 20210310; CN 110938852 A 20200331; CN 110938852 B 20231212; ES 2872278 T3 20211102

DOCDB simple family (application)

EP 19198876 A 20190923; CN 201910896690 A 20190923; ES 19198876 T 20190923