Coating composition and surface protective film forming method

An object of the present invention is to provide a coating composition that has little odor, is easy to construct, is excellent in drying property and curability at room temperature, and the resulting coating film is excellent in scratch resistance and crack resistance. The present invention includes (A) an epoxy silane oligomer having an epoxy group and a siloxane bond and a weight average molecular weight of 500 to 20,000, (B) colloidal silica having an average primary particle diameter of 1 to 100 nm, and (C ) It relates to a coating composition containing a curing catalyst.