SC-CO_2抗溶沉淀制粉末涂料研究(Ⅱ)——含SC-CO_2的涂料液抗溶沉淀制粉末涂料

将压力22MPa、温度70℃、含环氧/聚酯树脂40%、甲苯40%、CO220%(质量分数)的涂料液,经孔径0.4mm、孔深0.5mm,孔前孔后设有45°、1mm深锥角的喷嘴雾化入温度35℃、压力10MPa、内径Φ50mm、高1.6m的抗溶沉淀釜中,得平均粒径约为65μm的环氧/聚酯粉末涂料,该涂料涂膜满足HG/T2006-2006标准。试验表明,用SC-CO2代替部分甲苯先对粉末涂料液进行稀释,以利雾化,进而参加抗溶沉淀,能有效地减少溶剂甲苯用量,减轻抗溶沉淀釜的干燥负荷,节能效果明显。

Study on the Preparation of Powder Coatings by Precipitation Antisolvent Technology of SC-CO2(Ⅱ)——Preparation of Powder Coatings from SC-CO2 Containing Solution by Precipitation Antisolvent Technology

In this paper,the solution（compositions：epoxy/polyester resin of 40%（mass）,toluene of 40%（mass）,CO2 of 20%（mass）） is atomized into an autoclave （with pressure of 10 MPa,temperature of 35 ℃,inner diameter of 50 mm and height of 1 600 mm） through nozzle （with pore diameter of 0.4 mm,pore depth of 0.5 mm,and cone angle of 45° and 1 mm cone depth） at the pressure of 22 MPa and the temperature of 70 ℃,and epoxy/polyester powder coatings are obtained with average diameter of 65 μm.The coatings can comply with the standard HG/T2006-2006.Through experiments,it is showed that supercritical CO2 （SC-CO2） being used to dilute powder coatings solution partially replacing toluene is beneficial to atomization and participates in precipitation antisolvent action,effectively reducing the use amount of toluene,decreasing the drying burden of autoclave and presenting apparent energy-saving effect.