| abstract |
Coating agents, wherein the starting materials of the coating agent consist of nano-SiO 2 , a film-forming substance, a film-forming assistant, an acid and water and the coating agent has a pH of 3-9; wherein, based on 1 liter of the coating agent, the amount of nano-SiO 2 is 50-100 g, the amount of film formation of the substance is 80-100 g, the amount of film-forming auxiliary is 20-40 g, and the amount of acid is 25-40 g is; wherein the nano-SiO 2 has an average particle size of 50 nm or less; wherein the film-forming substance is one or more selected from (meth) acrylic acid resin, epoxy resin, styrene-acrylate emulsion, silicone-acrylate emulsion and polyurethane resin, each having a weight-average molecular weight of 8,000-200,000; in which the film-forming assistant is one or more selected from silane coupling agent, triethylamine and tetraethyl orthosilicate; and where the acid is phosphoric acid and / or phytic acid; characterized in that the coating agent additionally contains an accelerator in an amount equal to 10-20 g, wherein the accelerator is one or more substance (s) selected from sodium silicate, sodium fluoride, sodium pyrophosphate, sodium phosphate, acetone, ethylene glycol, ethanol and triethyl phosphate. |