An Attempt To Chlorinate Copper Phthalocyanine Blue Using Ionic Liquid

Abstract

The chlorination of this pigment is done to produce Copper Phthalocyanine green. This green pigment helps to produce a variety of green shades. Numerous shades of blue can be made using this basic blue pigment. The chlorination done traditionally involves the use of organic petroleum-derived solvents like dichloromethane, hexane, toluene, ethyl benzene etc. These organic solvents are potential carcinogens along with being non-renewable at the same time. Also, the traditional chlorinating agents include sulfonyl chloride, thionyl chloride, sulphur monochloride etc. which are costly as well as harmful. Ionic liquids are made up of ions and ion pairs. These have very low melting points and are mostly liquids at room temperatures. They have good selectivity for water and organics. Moreover, these can be synthesised in the laboratory as per the requirement by varying the cation and anion combinations thereby enabling them to be tailored to suit a given application. Easy recovery and recycle at the end of the process as well as good solubilities have accelerated the use of ionic liquids as solvents in recent past. Following research sheds light on the use of the ionic liquids 1-butyl-3-methylimidazolium bromide [BMIm][Br] and 1-butyl-3-methylimidazolium tetrafluoroborate [BMIm][BF4] as solvents in the chlorination of Copper Phthalocyanine blue. The process involves the synthesis of the ionic liquid as stated in the literature and its characterisation as well as the subsequent application of the synthesised liquid for chlorination.