钙腐蚀面积评估法测定高阻隔塑料薄膜水蒸气透过率的研究

Study of Determining Water Vapour Transmission Rate of High Barrier Plastic Films by Calcium Corrosion Area Assessment

根据金属钙膜与水蒸气间的氧化化学反应使钙膜变透明的原理,实验通过测量钙膜腐蚀面积表征透过高阻隔薄膜水蒸气质量,从而测定高阻隔塑料薄膜水蒸气透过率。以真空蒸镀钙膜为前处理手段,以定时监测钙腐蚀面积为检测手段,分析腐蚀时间、钙膜厚度和样品阻隔性对水蒸气透过率检测的影响。结果表明:在40℃和90%RH环境条件下,采用200 nm钙膜厚度,在钙腐蚀初期,标称水蒸气透过量为10^(-6)~10^(-3)g/(m^(2)·24 h)区间内的高阻隔和超高阻隔塑料薄膜,其钙腐蚀面积与水蒸气透过质量呈良好的线性关系,水蒸气透过率测定结果分别为1.2×10^(-3)g/(m^(2)·24 h)和9.3×10^(-7)g/(m^(2)·24 h),RSD为11.6%和16.5%。钙腐蚀法测试高阻隔和超高塑料薄膜水蒸气透过率的结果较好;该方法在电子元器件、太阳能电池和有机发光二极管中高阻隔和超高阻隔封装材料的水蒸气透过率的测定具有较高的应用前景。

According to the principle that the oxidation chemical reaction between metal calcium film and water vapor makes calcium film transparent,this experiment measures the corrosion area of calcium film to characterize the quality of water vapor passing through high barrier plastic film,so as to measure the water vapor transmission rate of high barrier plastic film.The effects of corrosion time,thickness of calcium film and barrier property of samples on the determination of water vapor permeability were analyzed with vacuum evaporation calcium film as pretreatment method and regular monitoring of calcium corrosion area as detection method.The results show that at 40℃and 90%RH,the high barrier and ultra-high barrier plastic films with a thickness of 200 nm and a nominal water vapor permeability of 10^(-6)~10^(-3) g/(m^(2)·24 h)at the initial stage of calcium corrosion show a good linear relationship between the calcium corrosion area and the water vapor permeability.The water vapor permeability is 1.2×10^(-3) g/(m^(2)·24 h)and 9.3×10^(-7) g/(m^(2)·24 h),respectively,with RSD of 11.6%and 16.5%.The results of water vapor transmission of high barrier and ultra-high barrier plastic films by calcium etching method are good,and this method has a high application prospect in the measurement of water vapor transmission of high barrier and ultra-high barrier packaging materials in electronic components,solar cells and organic light emitting diodes.