Patent GB-345939-A (GB)
Title: Improvements in or appertaining to the manufacture of polymerised hydrocarbons and application thereof
IPC: C08F236/10
Filed: 1929-12-16
Abstract: Caoutchouc, synthetic; polymerized styrene, naphthylethylene, divinylbenzene, and their homologues.-A mixture of a diolefine such as butadiene, isoprene, dimethyl butadiene, or 2-methyl pentadiene-2 : 4 and an aromatic olefine (but not one which is hydrogenated) such as styrene, naphthyl ethylene, divinylbenzene, and their homologues, is polymerized to form a solid mass which may resemble rubber or deresinated gutta-percha, and is suitable for the insulation of submarine cables.  The polymerization may be effected by heating in an autoclave at 20-201 DEG  C., the time required varying with the temperature.  Catalysts such as sodium or sodium amalgam may be added.  An antioxidant such as phenyl a - or BETA-naphthylamine may be added to the product, or to the initial mixture of hydrocarbons, and a non-volatile hydrocarbon swelling agent such as liquid paraffin, petrolatum or paraffin wax may be added before the polymerization to render the product thermoplastic.  Thermoplastic products to be extruded upon a conductor such as those described in Specification 323,038, [Class 70, Indiarubber &c.], may be modified by replacing the whole or a part of their natural rubber content by the product of the present invention; if only part of the natural rubber is thus replaced, it is convenient to allow the remaining rubber to swell in and imbibe the liquid hydrocarbons to be polymerized, and a mineral or synthetic wax may be dissolved in the hydrocarbon mixture, so as to be imbibed by the rubber.  Preferably the polymerization temperature is not above 125 DEG  C. in presence of natural rubber, and oxygen may be excluded.  The product of the invention may be milled with natural rubber, gutta-percha or balata (whether or not deresinated or partly deresinated) or wax or the like.  In an example about 60 per cent styrene and 40 per cent 2-3 dimethyl butadiene are mixed with 5-15 per cent of mineral wax in an autoclave and polymerized.  The product may be extruded about a conductor and surrounded by guttapercha or the product of Specification 323,038 or other suitable oxygen-resisting substance and then armoured in a known way; or alterate layers of the polymerized mixture and gutta-percha may be used.  Vulcanization may be effected as described in Specification 340,302, [Group V].ALSO:A mixture of a diolefine and an aromatic olefine such as styrene, naphthylethylene, or divinyl benzene, and their homologues (but not one which is hydrogenated) is polymerized to form a solid mass which may resemble rubber or deresinated guttapercha, and is suitable for the insulation of submarine cables.  An antioxident such as phenyl a or b -naphthylamine may be added to the product or to the initial hydrocarbons, and a non-volatile hydrocarbon swelling-agent such as liquid paraffin, petrolatum, or paraffin wax may be added before the polymerization to render the product thermoplastic.  Thermoplastic products such as those described in Specification 323,038, [Class 70, Indiarubber &c.], may be modified by replacing the whole or a part of their natural rubber content by the product of the present invention. The product of the invention may be milled with natural rubber, guttapercha, or balata (whether or not deresinated or partly deresinated) or wax, or the like.  In an example, about 60 per cent of styrene and 40 per cent 2-3 dimethyl butadiene are mixed with 5-15 per cent of mineral wax in an autoclave and polymerized.  The product may be extruded about a conductor. Vulcanization may be effected as described in Specification 340,302.  Reference has been directed by the Comptroller to Specifications 339,255, [Class 70, Indiarubber &c.], and 342,314.