Patent GB-799465-A (GB)
Title: Lubricants containing polypropylene
Filed: 1956-10-19
Abstract: Polypropylenes having a molecular weight over 30,000 and up to 500,000 are prepared (see Group IV (a)) by polymerizing propylene in the presence of a catalyst prepared by mixing an aluminium compound RR1AlX (where R and R1 are H, alkyl or acyl radicals and X is R or a halogen alkoxyl, aryloxy or mercapto radical) with a reducible compound of a heavy metal of Group IVa, Va or VIII of the Periodic system in a molar ratio between 1:1 and 12:1 are added in minor proportion to lubricating oil and grease compositions.  The lubricating oil may be a mineral, synthetic, animal or vegetable oil or any mixtures thereof, examples of synthetic oils being esters, e.g. of C8 oxo alcohol and C8 oxo acid, of C13 oxo alcohol and octanoic acid, di - (2 - ethyl hexyl) sebacate, di - nonyl adipate, and of C13 oxo acid and tetraethylene glycol; complex esters, e.g. sebacic acid/tetraethylene glycol/2-ethyl-hexanoic acid or 2-ethyl hexanol and azelaic acid/tetraethylene glycol/C8 oxo alcohol/C8 oxo acid; phosphoric acid esters such as that formed by the reaction of the mono methyl ether of ethylene glycol and phosphorus oxychloride; halocarbon oils, e.g. the 12-unit polymer of chlorotrifluoroethylene; polysiloxanes, e.g. methyl, ethyl, methyl-phenyl, and ethyl-phenyl polysiloxanes, sulphite esters, e.g. the reaction product of sulphur oxychloride and the methyl ether of ethylene glycol; carbonates, e.g. the reaction product of tetraethylene glycol and the half ester of Cr oxo alcohol and ethyl carbonate; mercaptals, e.g. the reaction product of 2-ethyl hexyl mercaptan and formaldehyde; formals, e.g. from C13 oxo alcohol and formaldehyde; and polyglycols, e.g. the condensation product of butyl alcohol and propylene oxides. Petrolatum may also be used as the lubricating oil.  When used in greases the polypropylene may be the sole thickening agent or it may be used o modify greases containing metal soaps, salts or salt-soap complexes or other thickeners such as carbon black, silica gel and polyethylene.  The soaps or salts are preferably those of alkaline earth metals and C12-30 or C1-10 acids which are extensively described and include saturated, unsaturated and hydroxy mono- and polycarboxylic acids.  Optional ingredients of the compositions are detergents, e.g. calcium petroleum sulphonate; anti-oxidants, e.g. phenyl alpha naphthylamine; V.I. improvers, e.g. polyisobutylene; pour depressants, e.g. chlorwax-naphthalene condensation products and dyes for lubricating oil compositions and corrosion inhibitors, e.g. sorbitan mono-oleate and anti-oxidants, e.g. phenyl alpha naphthylamine for lubricating grease compositions.  In examples polypropylene having a molecular weight of about 100,000, prepared by polymerizing propylene in the presence of a catalyst comprising titanium tetrachloride, aluminium triethyl and diethyl aluminium bromide in n-heptane, is incorporated in lubricating greases prepared from (i) animal fat, hydrated lime, water and a naphthenic mineral oil; (ii) glacial acetic acid, hydrogenated castor oil, hydrogenated fish oil acids, hydrated lime, phenyl alpha naphthylamine and a naphthenic mineral oil; (iii) naphthenic mineral oil and phenyl alpha naphthylamine, the polypropylene being the thickener; and (iv) naphthenic mineral oil and polyethylene with or without phenyl alpha naphthylamine.ALSO:Polypropylenes having a molecular weight over 30,000 and up to 500,000, prepared by polymerizing propylene in the presence of a catalyst formed by mixing an aluminium compound RR1AlX (where R and R1 are hydrogen or alkyl or aryl radicals and X is R or a halogen, alkoxy, aryloxy or mercapto radical) with a reducible compound of a heavy metal of Group IVa, Va, VIa or VIII of the Periodic system in a molar ratio between 1 : 1 and 12 : 1, are added to lubricating oil and grease compositions (see Group III).  The catalyst is preferably prepared by mixing the aluminium compound and the reducible compound in an inert liquid diluent, e.g. hexane or heptane at room temperature.  Aluminium compounds mentioned are aluminium trimethyl, triethyl, triisopropyl, triisobutyl, diethyl bromide and chloride, diphenyl bromide and chloride, triphenyl, hydride, ethyl dihydride, diethyl hydride and ethoxy diethyl. Reducible compounds mentioned are the halides (e.g. chlorides and bromides), oxyhalides (e.g. oxychlorides), oxides, hydroxides, or organic compounds such as alcoholates, acetates, benzoates or acetyl acetonates of Ti, Zr, Hf, Th, U, V, Nb, Ta, Cr, Mb and W.  The polymerization reaction may be carried out in sufficient inert liquid diluent to keep the polymer product concentration below 40 wt. per cent using temperatures up to 250 DEG  C. (preferably 50-85 DEG  C.), pressures up to 250 atmospheres (preferably 10 to 100) for reaction times of 0.5 to 20 hours (usually 2 to 10).  The reaction may be stopped by adding a catalyst deactivator such as an alcohol, e.g. methyl, isopropyl or butyl alcohol.  The product is essentially insoluble in organic solvents and may be washed with alcohol or acetone.  It may be modified by exposure to ionizing radiation such as gamma rays.