Three different weather-resistant coatings were fabricated with the various weight ratios of a mill-base silicone/acrylic resin to let-down silicone /acrylic resin at 2:8, 3:7, and 4:6 respectively. The prepared coatings were tested to investigate the effect of composition of weather-resistant coatings on the physical properties. The thermal stability, salt spray exposure, and weather-resistance were improved with the increased silicone content. It was concluded that the optimum retio of mill-base silicone/acrylic resin to let-down silicone/acrylic resin would be 2:8 and the coating with 30 wt% of silicone content would have high weather-resistance.

The objectives of this study is to investigate the optimum reaction conditions and to identify the product formula in the synthesis of a silicone/acrylic resin that curing in moisture at room temperature. By the addition polymerization of monomers, n-butyl acrylate, methyl methacrylate, n-butyl methacrylate, and 3-methacryloxypropyltrimethoxysilane. a quarter polymer was obtained. Among various initiators investigated in this study, 2.2'-azobisisobutyronitrille was found to be the most suitable initiator. The optimum reaction conditions found in this study are 70 wt% of initial solvent amount, 120 minutes of dropping time, 3 times of initiator addition, 82~105℃ of reaction temperature, and 8 hrs of reaction time. Also, number average molecular weight of 11700~33100 and molecular weight distribution of 1.81~3.44 were obtained.