摘要 |
A composition suitable to form coating films on metal substrates, in particular acting as a primer, comprising an aqueous dispersion of a tetrafluoroethylene polymer and/or copolymer, containing phosphate ions and other anions of mineral acids and furthermore Mg and/or Mn in the form of divalent cations, the phosphate anion amount being such that, expressed as phosphorus/dry polymer weight ratio, it ranges from 0.005 to 0.15, and the amount of Mg ions and/or Mn ions being such that the Mg+Mn/P ratio expressed in atoms ranges from 0.1 to 2. |