Study On The Synthesis And Modification Of C.I.Pigment Red 48:2

The optimum synthesis technology of C.I.Pigment Red 48:2 was studiedin this paper. 2B acid was dissolved in ammonia liquor ,followed by theaddition of sodium nitrite and hydrochloric acid at the temperature of0～5℃.After the diazo reaction was conducted for 1h , the diazo solutionobtained was added to coupling solution within 20 minutes and the pH valueof the solution was kept at 9.0. Then Calcium chloride was added to themixture ,with the pH value of the solution being adjusted to 6.0～7.0 andraising the system temperature to 80℃ for maintaining 15 min.The surface modification of C.I.Pigment Red 48:2 was systematicallystudied by using individual and built surfactants respectively. Thesurfactants adopted in the paper included anionic surfactants such asdispersant MF, dispersing agent NNO, polyacrylic acid , sulfonated castoroil and sodium dodecyl sulfate , and two kinds of cation surfactants(Surfactant 1227 and emulsifying agent FM),as well asrosin ,s-rosin ,abietylamine and polymer dispersant. The results showedthat the addition of surfactants had the great influence on the propertiesof C.I.Pigment Red 48:2 .The hue, transparency, flowability ,colorstrength and dispersity of the said pigment were obviously improved byadding anionic surfactants, rosin and its derivative. The builtsurfactant system with rosin, anionic surfactant and polymer dispersantdisplayed better modification properties than the individual surfactantsystem .The results showed that the pigment obtained had fresh colour,high-color strength and high-transparency.Additionally ,the sand milling process was studied. The propertiesof C.I.Pigment Red 48:2 were influenced by milling time , solvent ,theaddition of surfactant, and etc. The high-color strength was obtainedby sanding.Finally,Cost was accounted and the process was designed. C.I.PigmentRed 48:2 has higher commercial value.