The invention relates to the technical field of
titanium dioxide, and discloses a preparation process of
oil paint core-coated
titanium dioxide, which comprises the following steps: a core layer is
rutile type
titanium dioxide particles with the particle size range of 0.1-0.5 mu m and the specific surface area of 8-15m < 2 > / g, an inorganic
coating layer is composed of
silicon dioxide and aluminum
oxide according to the
mass ratio of 1: (0.2-1.5), the
coating thickness is 5-15% of the
diameter of the core layer, and the inorganic
coating layer is composed of
silicon dioxide and aluminum
oxide according to the
mass ratio of 1: (0.2-1.5). Wherein the
silicon dioxide is coated by a hydrolytic deposition method, the aluminum
oxide is coated by a
sol-
gel method, the organic coating layer comprises a
copolymer containing a
silane coupling agent and organic silicon resin, the organic silicon resin is methyl phenyl silicon resin, the organic coating layer accounts for 1-8% of the total
mass of the
titanium dioxide, and the surface
contact angle of the organic coating layer is greater than or equal to 110 degrees. According to the preparation process of the
oil paint core-coated
titanium dioxide, an inorganic-organic gradient
coating system is constructed, so that the core-coated
titanium dioxide has a gloss
retention rate of more than 95% (ASTM D523) and a
delta E
color difference of less than 1.5 (ISO 7724) after 1000 hours in a QUV
accelerated aging test, and the
weather resistance of the core-coated titanium dioxide is improved by more than 3 times compared with that of the traditional titanium dioxide.