| Cobalt blue pigments as a kind of cloring agent with its properties of strong coloring ablility,high temperature resistance can be widely used in building sanitary ceramics and the decoration of domestic ceramics,especially in ink jet printing industry.In the field of the decoration of domestic ceramics,the fact that its weak acid tolerance limit its application in this field.This research was based on this point,cobalt blue pigments was synthesized by hydrothermal synthesis method.And then TEOS and cobalt blue pigments synthesized by hydrothermal method was used as the starting raw materials to prepare the inclusion cobalt blue pigments and solved the problem of poor acid tolerance in the decoration of ceramic overglaze decoration.In this research,cobalt nitrate and aluminum nitrate,aluminum chloride and cobalt chloride,cobalt sulfate and aluminum sulfate were used as raw materials,respectively.By adjusting pH value of Co-Al mixed precursor solution by titrating NaOH solution,cobalt aluminate?CoAl2O4?spinel pigments has been prepared by hydrothermal method after the precursor is hydrothermal reacted at 245?for 24h.The pigments were characterized by X-ray powder diffraction?XRD?,transmission electron microscopy?TEM?,DSC-TG thermal analysis,fouriertransform infrared spectroscopy?FT-IR?.The effects of different raw materials and different precursor pH values,organic additives?acetone and ethanol?,cationic surfactant CTAB and nonionic surfactant PVP on the pigments powder crystal phase composition,crystal morphologyand color performance were discussed.The research showed that CoAl2O4spinel pigments synthesis temperature would be reduced to 220?by adjusting organic solvent,then–b*value of the pigment with brighe blue tone and spherical particle was 33.89.The size of the spherical particle was about 50nm.Cobalt blue pigments was successfully coated with SiO2 by sol-gel method.The study focused on the effects of calcination temperature,Co/Si ratio,stirring time,amounts of ammonia,especially surfactant and Si/H2O ratio on the morphology,color and crystalline structure of SiO2 coated CoAl2O4 pigments?CoAl2O4@SiO2?.Furthermore,CoAl2O4@SiO2 inclusion pigments was baked on the white porcelain to investigate the temperature properties of inclusion pigments used as overglaze decoration pigments.Research results showed that CoAl2O4@SiO2 inclusion pigments could still maintain a certain blue tone and the pigments with best dispersion effect and b*value at?27.65 were obtained when Co/Si molor ratio was 0.5,the amount of NH3·H2O addition was 1.3g,stirring time was 4h,calcination temperature was1000?and the amount of PVP addition was 10wt%.At last,the results showed that the corrosion resistance of the pigments was improvedafter the CoAl2O4 pigments were coated with amorphous SiO2. |
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