Patent GB-513116-A (GB)
Title: Improvements in the manufacture of synthetic rubber-like materials
IPC: C08C19/08
Filed: 1938-03-21
Abstract: 513,116. Synthetic rubber. I. G. FARBENINDUSTRIE AKT.-GES. March 21, 1938, Nos. 8672 and 8673. Convention dates. March 20, 1937, and Nov. 11, 1937. [Class 2 (iii)] Synthetic rubber of improved plasticity is produced by heating the product of emulsion polymerization of butadiene hydrocarbons and applying an oxidizing treatment in the presence of an anti-oxidant. The butadiene hydrocarbon may be polymerized together with polymerizable substances other than dienes such as styrene and acrylic and methacrylic nitrile. Suitable anti-oxidants are phenyl-#- naphthylamine, p-tertiary amyl phenol disulphide and the products obtainable by reacting aromatic vinyl compounds with aromatic hydroxyl compounds in the presence of acid catalysts (Specification 456,359). The oxidizing treatment may be effected by milling or kneading the material for instance on heated rollers, and oxidizing agents may be present such as benzoyl peroxide, dinitrobenzene, and oil of turpentine. The oxidation may also be effected in the presence of oxidizable substances containing double bonds such as unsaturated hydrocarbons (isododecylene or an interpolymer of a butadiene and isododecylene or propylene).. In examples, (1) phenyl-#- naphthylamine is incorporated with a copolymer of butadiene and styrene and the mixture is worked on rollers at 120‹ C. or the same mixture in a crumbly state is heated on a perforated dish in a vessel at 130‹ C. under a circulating air-pressure of 3 atmospheres ; (2) a butadiene-styrene copolymer with p-tertiary amylphenol disulphide is heated in the latter way at 90-100‹ C. ; (3) a copolymer of butadiene and styrene is stirred, together with isobutyl phenol disulphide into an emulsion of benzoyl peroxide, water, benzene and alkylated naphthalene sulphonic acid; the polymerizate is precipitated by an electrolyte in a crumbly state and is then dried and heated in a autoclave as described above ; (4) methyl-phenol disulphide is added to the mixed polymer emulsion of the preceding example and the precipitated polymer is heated in an autoclave with air ; (5)-(7) to an emulsion of butadienestyrene copolymer is added (a) a mixture of isododecylene and tetrahydronaphthol, (b) a mixture of tetrahydronaphthol and a mixed polymer of butadiene and propylene, or (c) a mixture of the polymer of styrene and phenol (Specification 456,359) and the mixed polymer of butadiene and propylene, in each case the mixture being heated in air at 70‹ C. Specification 488,866 also is referred to. The Specification as open to inspection under Sect. 91 states that the oxidizing treatment may be applied by simply heating the polymer in the form of thin sheets or in a powdery or crumbly state and that the antioxidant may be admixed with the polymer by mixing the materials in a dissolved or dispersed state. As oxidizing substances there may be used aromatic nitro-compounds and inorganic peroxides. When the treatment is effected in the presence of substances containing double bonds, the plastifying effect is attained much more quickly, especially in the case of the bodies produced from phenol and styrene (Specification 456,359). Suitable anti-oxidants include aromatic amines such as alkyl and aryl naphthylamines, alkyl and aryl aminoanthracenes, diaryl phenylene diamines, aldol naphthylamines and alkylated phenols and their sulphides and polysulphides. This subject matter does not appear in the Specification as accepted.