Preparation of SiO _ 2 aerogel composite insulating coating

raw material

The experimental raw materials are: water-based acrylic resin, film-forming additives (Zhuhai Jili Chemical Co., Ltd.); hydrophobic SiO2 airgel (Guangdong Allison High-tech Co., Ltd.); titanium dioxide (HUNTSMAN); hollow glass microspheres ( 3M); far-infrared ceramic powder (Lingshou Xuhang Mineral Products Distribution Co., Ltd.); wetting agent, dispersant (Guangzhou Siluoke Chemical Co., Ltd.); defoamer (Rhodia); deionized water ( Laboratory self-made); aluminum alloy plate (commercially available).

Coating preparation

First, use a planetary ball mill to grind SiO2 airgel particles into powder, add wetting agent, dispersant, and some defoamers into deionized water, and stir at a speed of 500 r/min; after stirring for 3 min, add SiO2 airgel powder, the speed was increased to 1800 r/min, and its high-speed shear dispersion was carried out for 3 h to prepare SiO2 airgel slurry; then the speed was reduced to 700 r/min, and acrylic resin was added to form a film Add additives, stir evenly; finally add titanium dioxide, far-infrared ceramic powder, hollow glass microspheres and the remaining defoamer in sequence to obtain SiO2 airgel composite heat-insulating coating. Use a wire Bar Coater to evenly coat the coating on the aluminum alloy plate. The dry film thickness of the coating is about 60 μm, and it is cured and dried under natural conditions.

Performance Testing

The thermal conductivity of the coating was tested using a thermal conductivity meter from HOT DISK, Sweden. Hitachi U-4100 ultraviolet/visible light/near-infrared Spectrophotometer was used to test the solar reflectance of the coating with the integrating sphere method. The HWF-2 infrared emissivity measuring instrument of North Chihong Optoelectronics Co., Ltd. was used to test the infrared emissivity of the coating in the 8-14 μm band. Referring to the method in HC/T 4341-2012 "Heat-reflecting and heat-insulating coatings for metal surfaces", a self-made device for testing the heat-insulating performance of the coating was made, and the heat-insulating effect of the coating was tested. The dry film thickness of the coating was measured with a German Nix QNIX4500 coating Thickness Gauge.