Chromium-free surface-treated tinplate, production method and surface treating agent therefor
US11248298B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 2016 |
| Grant date | Feb 15, 2022 |
| Priority date | — |
| Expiry date | Jul 18, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C2222/20
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Provided are a chromium-free surface-treated tinplate, a production method and a surface treating agent thereof. By coating, on the surface of a tinplate, an environmentally friendly aqueous surface treating agent containing 0.1-5 wt % of a zinc salt, 0.1-5 wt % of a zirconium salt and/or a molybdenum salt and 5-30 wt % of siloxane or polysiloxane, a layer of chromium-free passivation film having uniform and dense ingredients and a good performance and being stable is formed on the surface of a tin layer. The passivation film contains 0.1-20 mg/m2 of zinc, 0.1-20 mg/m2 of zirconium and/or molybdenum and 0.5-100 mg/m2 silicon. The passivation film can impart an excellent surface stability, corrosion resistance and paint film adhesion performance to the surface of the tinplate; in addition, contact with food is safe. The tinplate is comparable to chromium passivation in performance, and the production process thereof does not use a chromate, so that a truly green production process of a tinplate is achieved, complying with the requirements of increasingly strict environmental protection laws and regulations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.