| abstract |
Hydrocarbon oils and greases such as gasolene, kerosene, naphtha, and lubricants, are thickened by an oxygen-free linear polymer of acetylene or an acetylenic hydrocarbon or of a halogen derivative thereof. Acetylenic compounds specified are divinyl acetylene, diacetylene or its lower polymers, chlorprene, and alkyl or aryl derivatives of acetylene, e.g. propine, butine, phenyl - acetylene. The polymers are preferably stabilized by hydrogenation, destructive hydrogenation, halogenation, alkylation, depolymerization, condensation with other organic compounds, or addition of sulphur or hydrogen halide or other inhibitor of polymerization. The polymerization may be effected in the lubricating oil or in a solvent; polymers of m.w. 1100--8000 are suitable, a proportion of 0,2--40 per cent being used. The polymers may be broken down by milling, forcing a solution through a fine orifice or by heating; halogen polymers may be treated with alkali to remove part or all the halogen. There may be added to the thickened lubricants hydrogenated rubber, polymerized isobutylene or like poly-olefine, oxidation inhibitors, e.g. naphthols and thionaphthols, polymerization-inhibitors, e.g. sulphur or soluble sulphur compounds, load-carrying lead or sulphur compounds, oiliness improvers, e.g. fatty acids, carbon preventers, and sludge-dispersing agents. In examples: (1) divinyl acetylene dissolved in xylene is refluxed in presence of air or butylamine as catalyst for 2--5 hours at 80--90 DEG C. or at 10 to minus 50 DEG C. in presence of boron fluoride; the product preferably freed from unpolymerized divinyl acetylene by distillation, is hydrogenated at 15--25 DEG C. in presence of palladium, or at 30--90 DEG C. in presence of a copper chromite or an activated nickel catalyst; 5 per cent is added to a lubricating oil; (2) chlorprene, obtained by reacting vinyl acetylene with hydrogen chloride, is polymerized by heating in presence of air or other catalyst; the polymer may be added directly to lubricants, but is preferably first condensed with naphthalene or benzene in presence of boron fluoride, aluminium chloride, acetic acid solution of sulphuric acid, or other catalyst, or is alkylated, reacted with sodium polysulphide, or is condensed by the Wurtz process. |