Patent GB-389109-A (GB)
Title: The manufacture of emulsions of vinylacetylenes or their polymers or reduction products, and of synthetic rubber therefrom
IPC: C08J3/03
Filed: 1931-05-30
Abstract: Rubber-like products are obtained by successively polymerizing and coagulating an emulsion of a nonbenzenoid acetylene polymer, particularly mono- or di-vinylacetylene (cf. Specification 384,654), or of a polymerization product of a nonbenzenoid acetylene polymer (cf. Specification 384,655), or of an unsaturated mixture of reduction products of the polymerized or unpolymerized nonbenzenoid acetylene polymers (cf. Specification 389,108).  The emulsions are preferably prepared in an aqueous medium with the aid of emulsifiers or protective colloids, in which connection reference is made to hydrophile proteins such as egg albumen, glue, gelatin, and casein; water- or alkali-soluble resins such as shellac; agar-agar; soaps; sulphonic acid soaps recovered from the refining of petroleum; turkey red oil; and Twitchell's reagent.  At any stage before coagulation it is preferred to add to the emulsion an aqueous emulsion or suspension of a resin such as that obtained from Hevea or Guayule rubber by extraction with acetone; alternatively or in addition, a small amount of rubber latex or serum obtained therefrom may be added.  An antioxidant and a vulcanization accelerator may also be added. Examples of the preparation of divinylacetylene emulsions are given, as follows:--(a) a dilute aqueous solution of gelatin is mixed with sodium salts of sludge acids obtained in refining petroleum with sulphuric acid, and the mixture is agitated with divinylacetylene; (b) ammonium oleate is added to serum from rubber latex, and the mixture is agitated with divinylacetylene; (c) divinylacetylene is agitated with rubber latex containing sodium stearate.  The polymerization and coagulation of the emulsions may be effected by standard methods. The following examples are given:--(1) An aqueous emulsion of divinylacetylene, prepared with the aid of an aqueous solution of sodium naphthenate and gelatin, is mixed with an aqueous suspension of Guayule resin, and the mixture is allowed to stand for a week at atmospheric temperature; latex from Hevea rubber and a little hydroquinone are then added, and coagulation effected by addition of acetic acid; (2) as in example (1), except that the latex is omitted; (3) a mixture containing 1 : 4-dimethylbutadiene, prepared by reducing divinylacetylene, is emulsified as in example (1) and further treated as in that example, except that polymerization is effected by heating to 25 DEG  C. for six months. The coagulated product may be worked up similarly to raw rubber. Examples are given in which (a) the dried coagulum is milled with zinc oxide, sulphur, morpholylmorpholine dithionate (a vulcanization accelerator), and phenyl-a -naphthylamine, and the mixture is cured by heating at 140 DEG  C.; (b) the coagulum is superficially cured by treatment with a carbon bisulphide solution of sulphur chloride.ALSO:Rubber-like products are obtained by successively polymerizing and coagulating an emulsion of a non-benzenoid acetylene polymer, particularly mono- or di-vinylacetylene (cf. Specification 384,654), or of a polymerization product of a non-benzenoid acetylene polymer (cf. Specification 384,655), or of an unsaturated mixture of reduction products of the polymerized or unpolymerized non-benzenoid acetylene polymers (cf. Specification 389,108).  The emulsions are preferably prepared in an aqueous medium with the aid of emulsifiers or protective colloids, in which connection reference is made to hydrophile proteins such as egg albumen, glue, gelatin, and casein; water-or alkali-soluble resins such as shellac; agaragar; soaps; sulphonic acid soaps recovered from the refining of petroleum; turkey red oil; and Twitchell's reagent.  At any stage before coagulation it is preferred to add to the emulsion an aqueous emulsion or suspension of a resin such as that obtained from Hevea or Guayule rubber by extraction with acetone; alternatively or in addition, a small amount of rubber latex or serum obtained therefrom may be added. An antioxidant and a vulcanization accelerator may also be added. Examples of the preparation of divinylacetylene emulsions are given, as follows:--(a) a dilute aqueous solution of gelatin is mixed with sodium salts of sludge acids obtained in refining petroleum with sulphuric acid, and the mixture is agitated with divinylacetylene; (b) ammonium oleate is added to serum from rubber latex, and the mixture is agitated with divinylacetylene; (c) divinylacetylene is agitated with rubber latex containing sodium stearate; (d) divinylacetylene is emulsified with the aid of a aqueous solution of sodium naphthenate and gelatin.  An example is given also in which a mixture containing 1 : 4-dimethylbutadiene, prepared by reducing divinylacetylene is emulsified as under (d) above.ALSO:Rubber-like products are obtained by successively polymerizing and coagulating an emulsion of a non-benzenoid acetylene polymer, particularly mono- or di-vinylacetylene (cf. Specification 384,654, [Group IV]), or of a polymerization product of a nonbenzenoid acetylene polymer (cf. Specification 384,655), or of an unsaturated mixture of reduction products of the polymerized or unpolymerized nonbenzenoid acetylene polymers (cf. Specification 389,108, [Group IV]).  At any stage before coagulation it is preferred to add to the emulsion an aqueous emulsion or suspension of a resin such as that obtained from Hevea or Guayule rubber by extraction with acetone; alternatively or in addition, a small amount of rubber latex or serum obtained therefrom may be added An antioxidant and a vulcanization accelerator may also be added. The coagulated product may be worked up similarly to raw rubber. Examples are given in which (a) the dried coagulum is milled with zinc oxide, sulphur, morpholyl-morpholine dithionate (a vulcanization accelerator), and phenyl-a -naphthylamine and the mixture is cured by heating at 140 DEG  C.; (b) the coagulum is superficially cured by treatment with a carbon bisulphide solution of sulphur chloride.