Synthesis Of Monomer

Monomer of polyimide is Dianhydride (tetracid)and diamine. synthesis methods of diamine of more mature, many diamine is also a commodity supply.Dianhydride is a single special, in addition to curing agent for epoxy resin is mainly used for the synthesis of polyimide.Pyromellitic acid and trimellitic anhydride can be extracted by three heavy aromatic oil refining petroleum products were four toluene and partial three toluene by gas phase and liquid phase oxidation step by.Other important two anhydride, such as two phenyl ketone two anhydride, biphenyl two anhydride, two phenyl ether two anhydride, six f two anhydride etc by the synthesis methods, but the cost is very expensive, for example six fluorine two anhydride per kg to reach the million.Jiande City Solver Polyimide Co., Ltd. developed by o-xylene chlorination, oxidation and isomerization of 4- can be obtained by separation of chlorinated anhydride and 3- chlorophthalic anhydride of high purity, with this two kinds of compounds as raw materials can be synthesized a series of two anhydride, its large potential for cost reduction, synthetic route is valuable.