GB354310A - Improved manufacture of plastic substances - Google Patents

Abstract

Polysulphides of the alkali and alkaline-earth metals and ammonium containing an atomic proportion of sulphur from 1,5 to 3,75 are made by boiling the alkali in aqueous solution or dispersion with the necessary quantity of sulphur (wetted if desired by alcohol, acetone or alcohol-benzol mixture) according to the equation: 6NaOH+(2x+2)S = Na2S2O3 + 2(Na2Sx) + 3H2O. The sulphides Na2S1,5, Na2S2,75, Na2S2,85 and Na2S3,61 are specified. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the preparation of stabilized polysulphide solutions by boiling the alkali in aqueous solution or dispersion with sulphur for a long time. This subject-matter does not appear in the Specification as accepted. Reference has been directed by the Comptroller to Specification 302,270, [Class 2 (iii), Dyes &c.].ALSO:Olefine polysulphide plastics are made by reaction of a soluble polysulphide upon an olefine halogen additive compound characterized in that the atomic proportion of sulphur in the polysulphide is from 1,5 to 3,75. The products are normally hard and can be moulded under moderate heat. Soluble polysulphides of the alkali or alkaline earth metals and ammonium may be employed, preferably those of sodium, and are prepared by boiling the alkali, e.g. caustic soda in aqueous dispersion or solution with the necessary quantity of sulphur wetted, if desired, with alcohol, acetone, or alcohol-benzol, &c., according to the equation 6 NaOH + (2x + 2) S = Na2S2O3 + 2 (Na2Sx) + 3H2O. The sulphides Na2S1,5, Na2S2,75, and Na2S3,61 are specified. In an example, a hard plastic is obtained by refluxing a diluted solution of the sulphide Na2S2,85 with ethylenedichloride. The product may be moulded while soft, or after it has become hardened, it may be moulded on reheating. It can be cast at about 350 DEG F. The usual fillers, pigments, dyes, lakes, &c. may be incorporated. Large quantities of sulphur may also be incorporated to form strong rubber-like plastics. On heating these mixtures of sulphur and plastic at 260-270 DEG F. for 3-4 days rubber-like bodies of greenish-yellow colour are obtained which are permanently stable. The latter reaction is promoted by sulphur carriers, e.g. metallic oxides. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the preparation of plastics using stabilized polysulphide solutions obtained by boiling the alkali in aqueous solution or dispersion with sulphur for a long time. An example is also given in which a polysulphide Na2S2,2 is heated with ethylenedichloride in the presence of slaked lime and an alcohol to give a hard plastic. This subject-matter does not appear in the Specification as accepted. Reference has been directed by the Comptroller to Specification 302,270, [Class 2 (iii), Dyes &c.].ALSO:An olefine polysulphide plastic obtained from an olefine halogen additive compound and a polysulphide containing sulphur in the atomic proportion of 1,5-3,75 is compounded with the usual fillers, pigments, dyes, or lakes. Large quantities of sulphur may also be incorporated to form strong rubber-like plastics. On heating the latter mixtures at 260-270 DEG F. for 3-4 days rubber-like bodies of greenish yellow colour are obtained which are permanently stable. The product obtained by refluxing the polysulphide Na2S2,85 with ethylene-dichloride may be moulded while soft, or after it has become hardened, it may be moulded on reheating. It can be cast at about 350 DEG F. Reference has been directed by the Comptroller to Specification 302,270, [Class 70, Indiarubber &c.].