GB360890A - Improved manufacture of plastic substances - Google Patents

Abstract

Stabilized polysulphide solutions are made by treating a solution of an alkaline or alkaline earth hydroxide with sulphur and boiling for 15-20 hours under reflux or in an autoclave till stable equilibrium is attained. In an example caustic soda solution is mixed with sulphur (wetted if desired with an alcohol, acetone, &c.) and boiled till the sulphur has entered into combination. More caustic soda is then added and the mixture refluxed for 20 hours. Various polysulphides may be similarly made according to the equation: 6 NaOH + (2x + 2) S = Na2S2O3 + 2 (Na2Sx) + 3H2O where x = the atomic proportion of sulphur in the desired polysulphide. Polysulphides from Na2S17-5 to Na2S4-72 are specified. The Specification as open to inspection under Sect. 91 (3) (a) comprises also ammonium polysulphides. This subject-matter does not appear in the Specification as accepted.ALSO:Olefine-polysulphide plastics are made by causing an olefine halogen additive compound to react with a polysulphide solution which has been stabilized by boiling it for 15-20 hours at ordinary or increased pressure. Solvents, e.g. alcohols &c., and/or calcium hydroxide may be present. Alkali and alkaline earth metal polysulphides are specified. In examples (1) a hard plastic is made by heating a stabilized solution of the polysulphide Na2S2-2 with slaked lime, an alcohol and ethylenedichloride; the product after washing is white and may be readily moulded; it may be incorporated with the usual dyes, pigments and fillers; (2) a softer product is obtained using stabilized solutions of polysulphides Na2S3 to Na2S3-75, Na2S4-72. Specifications 302,270, [Class 2 (iii), Dyes &c.], 354,310, and 354,394 are referred to. Stabilized polysulphide solutions are made by treating a solution or suspension of an alkali or alkaline earth hydroxide with sulphur and boiling for 15-20 hours under reflux or in an autoclave till stable equilibrium is attained. In an example, caustic soda solution is mixed with sulphur (wetted if desired with alcohol, acetone, &c.) and boiled till the sulphur has entered into combination. More caustic soda is added and the mixture refluxed for 20 hours. Various polysulphides may be similarly made according to the equation: 6 NaOH <FORM:0360890/IV/1> where X = the atomic proportion of sulphur in the desired polysulphide. Polysulphides from Na2S1-75 to Na2S4-72 are specified. The Specification as open to inspection under Sect. 91 (3) (a) refers also to the preparation of plastics from reactive olefine compounds and unstabilized polysulphides in presence of a solvent and from reactive olefine compounds and unstabilized polysulphides in the presence of a finely divided insoluble base with or without a solvent. The use of ammonium polysulphides is specified. This subject-matter does not appear in the Specification as accepted.ALSO:Plastic compositions are made by incorporating olefine-polysulphide plastic with mineral pigments, rubber dyes, lakes and fillers, e.g. wood flour, magnesium carbonate, whiting, carbon black. The olefine-polysulphide plastics themselves resemble vulcanite in their physical properties and can be readily moulded.