The invention discloses a preparation method of a
coating paint film containing modified silica
sol. The preparation method comprises the following procedures: (1) adding
toluene diisocynate and the like into a first reaction kettle, so as to obtain a primary product; (2) adding
dimethylolpropionic acid and the like into the primary product, so as to obtain an aromatic waterborne
polyurethane emulsion; (3) preparing modified silica
sol; (4) adding the modified silica
sol and the aromatic waterborne
polyurethane emulsion into a third reaction kettle, so as to obtain a mixed
emulsion; (5) adding a proper amount of acrylic
copolymer sylvite and the like into the fourth reaction kettle containing
distilled water, so as to obtain a mixed base solution; (6) adding the mixed emulsion into the mixed base solution, so as to obtain a
coating containing the modified
silica gel; (7) carrying out air-
drying on a
plastic film, and diluting the
coating containing the modified
silica gel; and (8) spraying the coating containing the modified
silica gel to the
plastic film, so as to obtain the coating paint film containing the modified silica sol. The paint film prepared by virtue of the preparation method can be used for conveniently testing the properties such as tensile property,
corrosion resistance, vapor permeability and peel strength of the coating containing the modified silica sol.