Metal surfaces usually carry processing oil, oxide layers and microscopic contamination. No interfacial monomer can compensate for unstable pretreatment.
Phosphate P-OH groups can coordinate or condense with metal-surface hydroxyls and ions, while the acrylate end joins the free-radical network. For anti-corrosion primers, validate wet adhesion, scribe creep and adhesion after immersion, not only the initial cross-hatch result.
KM2110 suits systems needing strong interfacial anchoring; KM2120 suits lighter and clearer formulations; KM2140 suits lower-acid, flexible systems where peel strength matters. When used with phosphate corrosion-inhibiting pigments, validate interfacial anchoring and inhibition separately.