Cuprous bromide and cupric bromide form a 1 to 1 molar complex with N,N'-disubstituted alkylene or cycloalkylene diamines having from 2-3 carbon atoms between the two nitrogen atoms and whose two substituents on the two nitrogens are isopropyl or .alpha.-tertiary alkyl. These complexes have been found to have unique properties as catalysts in the oxidative coupling of phenols to polyphenylene oxides in solvent systems heretofore requiring removal of the water formed as a by-product during the reaction.
Methods for preparing copper(I)-diamine-phenoxide complexes within solution, such as the polymerization medium of polyphenylene oxides, are described which utilize a copper-diamine-halide complex, an alkali metal hydroxide and a monohydroxy aromatic compound to generate effective catalysts without the scrupulous exclusion of moisture and air.
Polyphenylene oxides are prepared by the oxidative coupling of monohydroxy aromatic compounds such as 2,6-xylenol in the presence of copper-bromide-amine catalysts in which at least part of the amine component is a diamine such as N,N'diphenylethylendiamine, N,N'-diphenyl-N,N'-dimethylethylene diamine or N,N'-diphenylpiperazine. Other amines preferably present in the catalyst are a tertiary monoamine such as dimethyl-n-butylamine and a secondary monoamine such as di-n-butylamine. The diamines are characterized by a low rate of consumption during polymerization, and the catalysts prepared therefrom are hydrolytically stable.
Polyphenylene oxides are prepared by the oxidative coupling of monohydroxy aromatic compounds such as 2,6-xylenol in the presence of copper-halide-amine catalysts in which at least part of the amine component is an aromatic diamine such as N,N'-diphenylethylenediamine, N,N'-diphenyl-N,N'-dimethylethylenediamine, N,N'-diphenylpiperazine or N,N,N',N'-tetramethyl-o-phenylenediamine. Other amines preferably present in the catalyst are a tertiary monoamine such as dimethyl-n-butylamine and a secondary monoamine such as di-n-butylamine. These diamines are characterized by a low rate of consumption during polymerization, and the catalysts prepared therefrom are hydrolytically stable.
Polyphenylene oxides are prepared by the catalytic reaction of oxygen with a monohydroxyaromatic compound such as 2,6-xylenol in a solvent for reactants and product, in a two-stage process. The first stage is effected continuously in at least one and preferably not more than two back-mixed (e.g., tank) reactors, and the second stage in one or more batch reactors or, preferably, in a reaction system with limited back-mixing, typically a cylindrical reactor containing multiple agitated zones. In the case of a copper catalyst system, it is also preferred to pre-mix the non-gaseous constituents of the reaction mixture in an inert atmosphere.
Novel carboxylic acid metal salt/amine complexes of the formula in which A is the anion of cyanoacetic acid, pyrrolidonecarboxylic acid, maleimidylcarboxylic acid, succinylimidylcarboxylic acid, benzenesulphonic acid or toluenesulphonic acid or of a methanephosphonic acid monoester or benzenephosphonic acid monoester, Me.sup.2+ is a divalent metal cation and R.sub.1 is a long-chain polyoxyalkylene radical, are obtained by reacting 1 mol of a carboxylic acid metal salt of the formula with 1 mol of a diamine of the formula in a polar organic solvent and in the temperature range of 25.degree. to 200.degree. C. to give the complex compounds of the formula. The novel complex compounds are valuable curing agents for epoxide resins and in mixtures with epoxide resins have an advantageous storage stability.
