Patent GB-1521050-A (GB)
Title: Process for preparing polyphenylene oxides
IPC: C08G65/00
Filed: 1975-12-16
Abstract: 1521050 Polyphenylene oxides GENERAL ELECTRIC CO 16 Dec 1975 [20 Dec 1974] 51416/75 Heading C3R A process of forming self-condensation products of a phenol under polymer forming reaction conditions comprises contacting a phenol with oxygen in solution in a solvent in the presence of a base and a mixture of a manganese chelate complex of the formula (L<1>)xMn, (Type A), where L<1> is a ligand derived from an orthohydroxyareneoxime and/or an omega hydroxyoxime, Mn is Mn(II), and x is at least 0À5, and a manganese chelate complex of the formula (L<2>)x Mn, (Type B), where L<2> is a ligand other than L<1>, and x is at least 0À5, and optionally in the presence of a primary amine, wherein the ortho-hydroxy arene-oxime is represented by the formula where Ra is hydrogen or C1-C5 alkyl, Ar is an at least divalent arene radical having at least one -OH radical and at least one radical attached directly to ortho-positioned arene ring carbon atoms; and the omegahydroxy-oxime is represented by the formula where Rb, Rc, Rd and Re are selected from hydrogen, acyclic and carbocyclic and heterocyclic organic radicals and n is 0 or 1. Suitable Type A complexes include Mn(II) bis(salicylaldoxime), Mn(II) bis(2-hydroxy-5-chlorphenyl-aldoxime), Mn(II) bis(2-hydroxy-5-methylacetophenoneoxime), Mn(II) bis(benzoinoxime), Mn(II) bis- (anisoinoxime), Mn(II) bis(furoinoxime), Mn(II) bis(acetoinoxime) and Mn(II) bis(methyl hydroxybutanoneoxime). In the Type (B) catalyst Mn is preferably Mn(II) and the ligand molecules contain 2 or more functional groups having atoms capable of combining with a Mn atom by donating a pair of electrons. Suitable functional groups are -OH, -SH, = O, -NH2, -NRH, = NH, -N =, -O-R, = NOH, -S-, R being an acyclic or cyclic organic radical. Numerous Type (B) ligands (L<2>) are listed examples being ethylene glycol, propanediol, acetylacetone, salicyl-aldehyde, dihydroxybenzene, dimethyl glyoxime, pyridinealdoxime, aminoalkanols, aminophenol, benzenedithiol, benzil-mono-oxime, thiosemicarbazide, pyridine-2-aldazine, 2- mercaptoethylamine, bis(salicylaldehyde)alkylene diimines, and 1, 8 bis(salicylidene-amino)-3- 6-dithiaoctane. The phenol used in the reaction may be represented by the formula where X is hydrogen, Cl, Br or I, R<1> is a monovalent radical selected from hydrogen, hydrocarbon, hydrocarbonoxy, halohydrocarbon and halohydrocarbonoxy radicals having at least 2 carbon atoms between the halogen atoms and the phenol nucleus, and R<11> is the same as R<1> and in addition halogen. The primary amine may be represented by the formula R<1>(NH2)y where R<1> is a mono- or poly-valent aliphatic or aromatic radical, y is at least 1 and wherein (a) at least 3 carbon atoms separate any amino (NH2) group from any other amino (NH2) group, and (b) at least 2 carbon atoms separate any amino (NH2) group from any other nucleophile, e.g. -NHR<2>, -NR<2>2, OH, -OR<2>, -OOCR<2> groups where R<2> is alkyl. Numerous primary amines are listed. The reaction may be carried out at 0-60‹ C. and preferably in a basic reaction medium, e.g. in the presence of an alkali metal hydroxide or alkoxide. In the Examples polyphenylene oxides are prepared by oxidizing 2,6-xylenol in the presence of NaOH and Mn(II) bis(salicylaldoxime) and either Mn(II) bis(salicylaldehyde) ethylene diimine or Mn(II) bis(acetylacetonate), using toluene and methanol as solvents. The reaction is stopped by neutralizing with acetic or sulphuric acid.