| abstract |
The invention belongs to the field of paints, and in particular relates to a water-based epoxy primer for pre-coating coils and a preparation method thereof. The epoxy primer, in parts by weight, comprises: 30-60 parts of water-based epoxy emulsion; pigments and fillers 10-20 parts; 2-6 parts of amino resin; 0.1-0.5 part of substrate wetting agent; 0-0.5 part of leveling agent; 1-5 parts of water-based salt spray resistance additive; 10-30 parts of water; amino resin includes Fully and/or partially methyl etherified amino resins; substrate wetting agents include one or more of silicone-based, nonionic and anionic substrate wetting agents; leveling agents include acrylic leveling agents and / or fluorine-modified acrylic leveling agent. By designing suitable amino ratio, pigment-to-base ratio and selecting suitable additives, the present invention enables the provided epoxy primer to be rapidly cured at a temperature of 200-250 DEG C of a galvanized sheet or a galvanized aluminum sheet, and a paint film formed. It has the properties of high hardness, good adhesion, good flexibility and excellent resistance to salt spray time. |