GB939225A - Improvements in or relating to a process for the production of thermoplastic products derived from di-epoxy compounds - Google Patents

Abstract

Thermoplastic products are prepared by reacting (a) a di-hydric phenol of which at least one aromatic nucleus has at least one alkyl substituent with (b) a substantially equimolar amount of a diepoxy compound, in which process either the dihydric phenol or the diepoxy compound, or both, contain an SO2 group joining two aromatic nuclei, in the presence of an alkaline compound as catalyst, and in a solvent in which the dihydric phenol, the diepoxy compound and the product are at least partly soluble and p which is substantially non-reactive with the dihydric phenol or the di-epoxy compound, the reaction mixture being substantially free from water and the nature and the quantity of the solvent and the temperature being such that the reaction product remains dissolved in the reaction mixture until the product has an intrinsic viscosity (measured in dimethyl formamide) of at least 0,4. A list of suitable phenols (a) is given, of which the preferred compound is 3,31,5,51-tetramethyl-4,41-dihydroxy diphenyl sulphone, and the preferred alkyl substituents in general are methyl and ethyl. The preferred diepoxy compounds are the diglycidyl ethers of the above phenol and of bisphenol A. The preferred alkaline catalyst is the mono sodium salt of the above phenol, the salt being counted as phenol from the point of view of molar calculations. Long lists of suitable solvents are given including ketones, nitriles, nitro compounds, sulphoxides and sulphones, a mixture of acetophenone and sulpholane being used in the example. The products may be used as threads of fibres.ALSO:3,315,51-Tetramethyl-4,41-dihydroxy diphenyl sulphone is prepared:-(1) from 2,6-dimethyl phenol and sulphuric acid: (a) one-stage, by reacting them in the presence of an organic solvent, e.g. tetrachloroethane; (b) two-stage, reacting them in equimolar quantities to prepare the para-sulphuric acid, and continuing the reaction with the same quantity of the phenol; (2) from 2,6-dimethyl phenol and ether a sulphur dihalide or a thionyl halide, e.g. the chlorides, the resultant sulphide or sulphonide being then oxidized to the sulphone in the oxidizing agent, e.g. H2O2, or a peracid, e.g. peracetic acid.