Synthesis of silicone-acrylic resins and their applications to superweatherable coatings

Silicone-acrylic resins were synthesized to prepare superweatherable paints for building materials. The raw materials used were n-butyl acrylate, methyl methacrylate, and n-butyl methacrylate as acrylic monomers and 3-methacryloxypropyltrimethoxysilane (MPTS) as a silicone monomer reactive with the acrylic monomers. Acrylic copolymers were synthesized such that their glass-transition temperatures were adjusted to 30 degreesC and their MPTS contents were varied to 10, 20, and 30 wt %. As the content of silicone and MPTS increased, average molecular weight and viscosity increased, and thermal stability at high temperatures improved. When we tested the properties of coatings by blending the synthesized silicone-acrylic resins with a white pigment, adhesion was superior with various substrates, and their properties were suitable on the whole. Weatherability was tested by an outdoor exposure test with a weather-ometer and an accelerated weathering tester, and their results showed that silicone-acrylic resin composed of 30 wt % MPTS was a superweatherable coating. (C) 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1614-1623, 2001.