| 摘要 |
1,213,882. Polyesters from monocyclic aromatic dinitriles. HALCON INTERNATIONAL Inc. 14 May, 1968 [15 May, 1967], No. 22836/68. Heading C3R. An oligomer which may be connected to a polyester resin is prepared by (a) glycolysis of a monocyclic aromatic dinitrile with water and ethylene glycol. (b) Contacting and recovering. the product diester. (c) Oligomerizing the diester to give an oligomer having an average of from about 4 to about 20 monomer units while removing the glycol formed, at least part of the ethylene glycol is recycled to stage (a) either with or without purification. The oligomer produced may be polymerized to give a polyester resin. Specified dinitriles are phthalonitrile, isophthalonitrile, tetraphthalonitrile and their monomethyl derivatives. Polymerization catalysts may be added to step (b) e.g. compounds of Sb, Zn, Ca, Ce, Al, Ti or Co. The glycolysis may take place in the presence of compounds of Fe, Sn and Pb. In the examples oligomers of average D.P. of 12 and 16 are disclosed. |
