Synthesis And Characterization Of Aniline Black1~#

The series of Aniline Black are very ancient pigments. Aniline Black1#is the darkness and the most transparent black pigment for ever known. It has the superior properties of being able to bear solvent、acid、alkali、light and heat, as well as undissolveble in water and unreacted with DOP. It also can be used as blue-mixed black. Whether used alone or not, it will be the best choice of high-blue-phase black clouring environment such as PU colour-syrup、colouring leather、painting、oil ink、 colouring resin. At present, our country’s demand of Aniline Black1#is about3000t/a, which mainly depends on import. It will produce more economic benefit if keep the initiative of production in our own hands.The production of Aniline Black1has two steps. Step one is the oxidation of Aniline to combine poly-aniline. Step two is the high temperature combination of aniline and nitrobenzene.The choice of oxidation has the fatal influence to the structure of intermediates. The poly-aniline oxidated by (NH4)2S2O8、H2O2-MnO2、(NH4)2S2O8-twain80has the approving poly-degree. The change of other industrial conditions have no business with the structure of intermediates. The change of poly-monomer gives other result, which proofs that the poly-monomer is aniline alone.In this experiment, the IR chart of production produced by high temperature combination of aniline and nitrobenzene is most similar to standard sample. Since the nitrobenzene is used as solvent and raw material, the experiment needs more nitrobenzene, and the excessive nitrobenzene can be recovered by distillation,which can improve the use-ratio of nitrobenzene. Poly-aniline turns from mix-phase to reduction-phase when it was treated with alkali, so that it loses the ability to react more.The best industrial condition to produce the intermediates is:make (NH4)2S2O8as oxidization, n((NH4)2S2O8):n(aniline)=0.8:1, n(HCl):n(aniline)=3:1, the temperature of dropping oxidization is5～10℃, reaction temperature is30℃, the time of dropping is2-3h, the react time is4h. The yield is95.5%.By means of apply-propetry testing, the production’s colour nearly like standard sample, the tinting intensity is88%, doesn’t dissolve in NMP, the property of being able to bear solvent is5level, the property of being able to bear migrate is4level (1level is the worst,5level is the best).