The invention provides a waterborne external
thermal insulation coating. The
coating consists of the following components in part by weight: 25 to 50 parts of functional filler, 30 to 50 parts of
emulsion, 20 to 35 parts of filler, 8 to 20 parts of film-forming aid, 1 to 3 parts of
wetting dispersant, 1 to 2 parts of
propylene glycol, 1 to 2 parts of defoaming agent, 0.5 to 1.5 parts of
mildew preventive, 1 to 5 parts of
thickening agent and 10 to 20 parts of water. The invention is characterized in that: the
coating is safe and environment-friendly, has excellent waterproof and anticorrosive properties, high
thermal resistance and
reflectivity, excellent
thermal insulation property, and good
weather resistance, is convenient to construct, and can be well adhered to various base materials, and the density of a dry film is low; an extremely thin hollow cavity layer is formed after the coating is coated on the surface of a base material and then is dried, so that an effective thermal barrier is formed; functional filler particles have large heated cathodes, low coefficient of
thermal conductivity, and
high heat reflectivity; the consumption of energy sources is remarkably reduced; the coating can reflect, refract and scatter
thermal radiation and stop heat conduction; and the energy is saved.