Hardness is a prime property envisaged in most industrial coating materials.This paper reports the development of hybrid coatings prepared by co-reacting a saturated polyester and a melamine resin(HMMM)which have been reinforced in-situ with a silicon based sol-gel precursor.The ratio of organic to inorganic phases were varied between 3 wt% and 14 wt%.Transparent coatings on glass substrate were made by altering the pH in the presence of paratoluenesolfonic acid as catalyst.It was found that samples having up to 8 wt% silicon precursor,cured at 170 deg C,remain fully transparent with improved hardness.These systems showed better properties compared to samples simply mixed by organic resins and nano-sized silica as pigment.
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