氧化锌包覆氧化铁黄颜料的制备及其耐热性能

Preparation and heat resistance of zinc oxide coated iron oxide yellow pigments

以六水合硝酸锌为原料,采用水热法制备氧化锌包覆的氧化铁黄颜料,考察不同六水合硝酸锌加料比(按氧化物物质的量比计,即n(Fe_(2)O_(3))∶n(ZnO)=10∶1,10∶3,10∶5,10∶7,10∶9)和包覆反应的不同水热处理温度(180、200、220、230、240℃)对氧化铁黄颜料耐热性的影响,并通过XRD、SEM、FTIR和TG-DTA对氧化铁黄颜料的结构和形貌进行表征。结果表明:氧化锌包覆后氧化铁黄颜色结构没有明显改变,保持针状形貌;随着六水合硝酸锌加料比的增加,氧化铁黄颜料的耐热性增强;水热处理温度为200℃时,在加料比为10∶7的条件下,氧化铁黄颜料色差值ΔE最小,为1.11,此时耐热性最好;水热处理温度为230℃时,包覆氧化铁黄颜料的色差值ΔE为4.35,超过该温度时包覆氧化铁黄颜料的耐热性大幅度劣化。

Zinc oxide coated iron oxide yellow pigments were prepared by using hydrothermal method taking zinc nitrate hexahydrate as raw materials.Effects of zinc nitrate content(feeding ratio n(Fe_(2)O_(3))∶n(ZnO)=10∶1,10∶3,10∶5,10∶7,10∶9)and coating hydrothermal temperature(180,200,220,230,240℃)on the heat resistance of iron oxide yellow pigments were investigated.Structure and morphology of the samples were characterized by using XRD,SEM,FTIR and TG-DTA.The results show that the structure of iron yellow sample is not significantly altered after zinc coating,maintaining the needle-like morphology.With the increasing of the feeding ratio of zinc nitrate oxide,the heat resistance of the samples is enhanced.When the hydrothermal treatment temperature is 200℃and the feeding ratio is 10∶7,the color difference of the samples is the smallest which is 1.11 with the best heat resistance.The color difference of the samples at the hydrothermal treatment temperature of 230℃is 4.35,and the heat resistance of the coated samples is greatly reduced beyond this temperature.