Coating composition, preparation method therefor and use thereof

A coating composition, comprising:

• based on a total weight of the coating composition,
• no more than 20% by weight of a composition of heat-expandable microspheres,
• 10%-30% by weight of a water-based thermoplastic resin,
• 10%-40% by weight of a water-based thermosetting resin, and
• 10%-35% by weight of a hot-melt filling resin,
• wherein:
• at least 60% of the heat-expandable microspheres have a wall thickness≤5 μm;
• a weight the heat-expandable microspheres having a particle size of 8 μm≤D≤20 μm is no less than 60% of the total weight of the heat-expandable microspheres;
• each of the heat-expandable microspheres comprises a thermoplastic polymer shell and a liquid alkane enclosed within the thermoplastic polymer shell, the liquid alkane being selected from ethane, propane, isobutane, n-pentane, isopentane, and mixtures thereof;
• the composition of the heat-expandable microspheres comprises dodecanol ester, an inorganic fiber selected from a nano-aluminosilicate fiber, a carbon fiber, a boron fiber, and mixtures thereof;
• wherein:
• the water-based thermoplastic resin is at least one selected from water-based acrylic resin and polyurethane resin;
• the water-based thermosetting resin is at least one selected from water-based epoxy resin and hydroxyl acrylic acid resin;
• the hot-melt filling resin is at least one selected from modified chlorinated polyvinyl chloride, polyester resin, polyurethane, polyamide, polyether sulfone, epoxy, and polymethylmethacrylate;
• a weight ratio of the water-based thermoplastic resin to the water-based thermosetting resin is 1:1-1:2;
• and
• a weight ratio of a sum of the water-based thermoplastic resin and the water-based thermosetting resin to the hot-melt filling resin is 1.5:1-2.5:1.