GB1201534A - Thermosetting plastics - Google Patents

Abstract

1,201,534. Polyarylene polyethers containing heterocyclic rings. IMPERIAL CHEMICAL INDUSTRIES Ltd. 20 Feb., 1969 [27 March, 1968; 17 May, 1968], Nos. 14767/68 and 23578/68. Heading C3R. The invention comprises thermoset resins containing units of formulµ in such proportions that (I) is in molar excess of (II) and the proportion of (III) is about twothirds of this molar excess, E being the residuum of a dihydric phenol, E<SP>1</SP> the residuum of a benzenoid compound having an inert electron withdrawing group in at least one of the positions ortho or para to the valence bonds and Z is =N- or =C(X)-, where X is halogen. A prepolymer may be obtained by reacting a double alkali metal salt of a dihydric phenol of formula with a dihalobenzenoid compound of formula and a polyhaloheterocyclic compound of formula where E, E<SP>1</SP> and Z are as above and X is halogen, the proportions being those of units I, II and III above. The prepolymer may be heated to obtain the thermoset resin. The compound IIa and an equimolar amount of a di-alkali metal salt of compound Ia may be replaced wholly or in part by an alkali metal salt of a halophenol of formula where Y is -SO 2 -, -SO- or -CO- or Y is Y<SP>1</SP>-A-Y<SP>11</SP>, where Y<SP>1</SP> and Y<SP>11</SP> are -SO 2 -, -SO- or -CO- and A is an organic radical having both valencies linked to carbon atoms. Also, the prepolymer may be prepared from a reaction mixture in which one of the components Ia, IIa or IIIa is partially or totally omitted, this component being added to the prepolymer to remove the deficiency before it is heated to obtain the cured resin. In examples, prepolymers are obtained from bis-(4-hydroxyphenyl) sulphone, bis-(4-chlorophenyl) sulphone and pentachloropyridine; the prepolymers are cured by heating and mixtures of the prepolymers with glass fibres and with asbestos fibres are cured by heating under pressure.