Studying On Preparation And Performance Of Nano-SiO₂/Amino-Acrylic Baking Paint

As an environmentally friendly paint,water-based amino-acrylic baking paint is widely used in daily life,such as agricultural machinery,electric vehicles,bicycles,security doors and other light industrial machinery.However,the current water-based amino-acrylic baking paint still has insufficient adhesion,hardness and weather resistance.In this paper,silica nanoparticles were prepared and incorporated into amino-acrylic baking paint emulsions.The influence of the particle size and concentration of silica nanoparticles on the performance of amino-acrylic baking paints was studied,and the best way to improve the performance of amino-acrylic baking paints was sought.The details are as follows:The semi-batch sol-gel method was used to prepare silica nanoparticles.The synthetic average particle size in the range of 120-150 nm with maximum mass production conditions was explored by changing the feeding method,the volume of tetraethylorthosilicate(TEOS)and absolute ethanol and other factors.First of all,when the volume of TEOS increased from 10m L to 20m L under the conditions of variable-point feeding,the average particle size of the prepared particles was still maintained in the range of 120-150 nm,the morphology was good and the yield was over 97%.Secondly,the minimum alcohol/water volume ratio for preparing SiO₂nanoparticles in the range of 120-150 nm was explored based on the TEOS volume of20 m L.The results showed that the ethanol amount required to obtain the particle size per unit mass was reduced by about 62.5%.In the synthesis process of amino-acrylic resin baking paint,Nano-SiO₂/Amino-Acrylic resin baking paint was prepared by adding SiO₂nanoparticle sol with different particle sizes and weight percentages,and its properties such as gloss,viscosity,adhesion,hardness,contact angle and salt spray resistance were characterized and tested.The results showed that as the particle concentration increased,the viscosity of the composite baking paint emulsion increased,the gloss gradually decreased,the contact angle of the paint film was between 57°-73°,the adhesion first increased and then decreased(up to 6.02 MPa),and the pencil hardness increased first and then declined(2H to 4H).The salt spray resistance was optimal when the weight percentage of the incorporated particles was between 1.0 wt%and1.3 wt%.In addition,the analysis of TGA spectrum and Fourier infrared spectrum showed that the addition of SiO₂ did not reduce the thermal stability of the original paint film,and could effectively improve the aging resistance of the amino-acrylic resin baking paint film.There are 26 figures,9 tables,100 references in this thesis.