Preparation Of Thick And Hard Coating Films Via Sol-Gel Process With A Low Temperature Treatment

SiO2-polymer hybrid thick and hard coating films were successfully obtained via sol-gel process with a heat treatment at 200 deg C. The films were achieved by control of hydrolysis and poly-condensation reaction of silica species. Key parameters were pH, water content and additional polymer in the coating solution. No cracking and highly transparent films were formed with polymer content in a range from 28 to 42 mass% (vs.SiO2). Their thickness was varied from 2.6 to 3.5um with an increase in the polymer content. Haze values of the films after Taber abrasion were very low and the pencil hardness was over 9H. Moreover, no damage was observed on the surface after steel wool abrasion with 4kg loaded.