Patent GB-835553-A (GB)
Title: Improvements in or relating to lubricants of high stability and a method of producing the same
Inventor: SALOMON TOBIE
IPC: C10M177/00
Filed: 1956-05-25
Abstract: Mineral and animal and vegetable lubricating oils are purified by contacting the oil, or a solution thereof in an organic solvent, successively and in either order with an anionic ion-exchange resin and a cationic ion-exchange resin for a time sufficient to reduce the amount of impurities in the oil to such an extent that the oil has an ash content of not more than 0.0001% by weight, even after the purified oil has been heated for 72 hours or more at between 115 DEG and 250 DEG  C. in the presence of a ferrous metal or a non-ferrous metal used in machinery bearings and of air or oxygen, and then removing the solvent, if one is used.  If desired, the oil may be additionally contacted with a mixed bed of anion and cation exchange resins.  Suitable cation exchangers are sulphonated polystyrene and phenolic resins and suitable anion exchangers are those of the aminated phenolic type.  Specified solvents for the oils are alcohols, ethers, esters such as ethyl acetate, ketones and hydrocarbons.  The impurities are stated to be inorganic salts and organic compounds such as sulphur compounds.  The purified oils are resistant to oxidation without the aid of anti-oxidants and/or anti-corrosion agents.  An example describes the purification of a white mineral oil by the three-stage method.ALSO:Synthetic lubricating oils, such as polyalkylene glycols, their ethers and esters, monoesters of fatty acids and of hydroxy fatty acids and polyesters of polycarboxylic acids, are purified by contacting the oil, or a solution thereof in an organic solvent, successively and in either order with an anionic ion exchange resin and a cationic ion exchange resin for a time sufficient to reduce the amount of impurities in the oil to such an extent that the oil has an ash content of not more than 0.0001% by weight, even after the purified oil has been heated for 72 hours or more at between 115 DEG  and 250 DEG  C. in the presence of a ferrous metal or a non-ferrous metal used in machinery bearings and of air or oxygen, and then removing the solvent if one is used.  If desired, the oil may be additionally contacted with a mixed bed of anion and cation-exchange resins. Suitable cation exchangers are sulphonated polystyrene and phenolic resins and suitable anion exchangers are those of the aminated phenolic type. Specified solvents for the oils are alcohols, ethers, esters such as ethyl acetate, ketones and hydrocarbons.  The impurities are stated to be inorganic salts and organic compounds such as sulphur compounds.  The purified oils are resistant to oxidation without the aid of anti-oxidants and/or anti-corrosion agents. Examples describe the purification of (1) the bi-ricinoleate of polyethylene glycol 400, in ethanol; (2) the bi-ricinoleate of polyethylene glycol 300; (3) a commercial di-(2-ethyl hexyl) sebacate; (4) a mono-ricinoleate of polyethylene glycol 300, in benzene; (5) a monolaurate of polyethylene glycol 300; and (6) a polyethylene glycol 300, in water, the ashcontents of the purified oils and sometimes of the impure oils, being given before and after subjection of the oils to the Weiss-Salomon test, using copper or iron.  The results, giving oils of ash content below 0.0001% in each case, are compared with the results obtained by too rapid a contact of the oils with the resins or by the replacement of the resins by alumina.ALSO:Synthetic lubricating oils such as polyalkylene glycols, their ethers and esters, are purified by contacting the oil, or a solution thereof in an organic solvent, successively and in either order with an anionic ion exchange resin and a cationic ion exchange resin for a time sufficient to reduce the amount of impurities in the oil to such an extent that the oil has an ash content of not more than 0.0001% by weight, even after the purified oil has been heated for 72 hours or more at between 115 DEG  and 250 DEG  C. in the presence of a ferrous metal or a non-ferrous metal used in machinery bearings and of air or oxygen, and then removing the solvent if one is used.  If desired, the oil may be additionally contacted with a mixed bed of anion and cation exchange resins.  Suitable cation exchangers are sulphonated polystyrene and phenolic resins and suitable anion exchangers are those of the aminated phenolic type. Specified solvents for the oils are alcohols, ethers, esters such as ethyl acetate, ketones and hydrocarbons.  The impurities are stated to be inorganic salts and organic compounds such as sulphur compounds.  The purified oils are resistant to oxidation without the aid of anti-oxidants and/or anti-corrosion agents.  Examples describe the purification of (1) and (2) the bi-ricinoleate of polyethylene glycol 400, in ethanol; (3) the bi-ricinoleate of polyethylene glycol 300; (6) a mono-ricinoleate of polyethylene glycol 300, in benzene; (7) a mono-laurate of polyethylene glycol 300; and (8) a polyethylene glycol 300, in water, the ash-contents of the purified oils and sometimes of the impure oils, being given before and after subjection of the oils to the Weiss-Salomon test using copper or iron.  The results, giving oils of ash content below 0.0001% in each case, are compared with the results obtained by too rapid a contact of the oils with the resins or by the replacement of the resins by alumina.