Patent · US Expired

Hexavalent chromium-free phosphate-bonded coatings

US6224657A · kind A · utility

23Cited by
13References
30Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 13, 1998
Grant dateMay 1, 2001
Priority date
Expiry dateOct 13, 2018

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02T50/60
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

A heat curable bonding composition of the present invention comprises an aqueous solution containing phosphate ion (PO.sub.4.sup.-3) and chromium(III) ion (Cr.sup.+3, or trivalent chromium) and is substantially free of hexavalent chromium ions. The bonding composition may further contain at least one secondary cationic species. The bonding composition has a pH in the range of about 1 to about 3.5.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.