GB377265A - Improved method for the manufacture of plastic materials - Google Patents

Abstract

Plastic material is prepared by the condensation of polyhydric alcohols, e.g. glycerine, glycol, polyglycerine, polyglycol, pentaerythrite, with the product obtained on oxidizing oils containing the glycerides of unsaturated acids. The process of oxidation may also cause saponification of the oil, in which case the glycerine set free may be removed or may be utilized as part of the polyhydric alcohol required for the condensation, but it is preferred to oxidize in such a way that the ester linkage is not destroyed, so that the dicarboxylic acids produced are already partly esterified. In either case, monocarboxylic acids may be removed from the oxidation product before the final condensation. Other mono- or polybasic acids and also other artificial and natural resins may be added prior to or during the condensation. In examples, (1) olive oil, dissolved in acetone or emulsified in potash solution, is oxidized with permanganate and the saponification completed by boiling. The manganese compound is filtered off, and the filtrate extracted with ether, or neutralized and extracted with alcohol. The solvent is removed, glycerine added to the residue, and the whole heated to 170 DEG C. to yield a resin. (2) Olive oil in acetone is oxidized with permanganate, and the whole treated with dilute sulphuric acid in the cold, whereby saponification is avoided. The monocarboxylic acids are removed by distillation in vacuo and the residue condensed as before. By using much less permanganate, some of the oleic acid is not oxidized, and very soft products are obtained. (3) Nitric acid is the oxidizing agent. (4) Linseed oil in chloroform is oxidized by means of ozone. In the Specification as open to inspection under Sect. 91 (3) (a) it is stated that the oils may first be saponified and then oxidized. This subject-matter does not appear in the Specification as accepted.