Patent GB-711211-A (GB)
Title: Improved lubricant blend
Inventor: MORTON RONALD WILLIAM
IPC: C07C69/34
Filed: 1950-08-24
Abstract: A lubricating composition (see Group III) comprises a dialkyl ester of a saturated dicarboxylic acid together with a polymer soluble in the dialkyl ester, the viscosity of the composition being greater than that of the dialkyl ester and the acidity of the dialkyl ester being less than 0.3 mg. KOH/gm.  In the examples, lubricating compositions are described consisting of (a) dinonyl sebacate (acidity 0.07 mg. KOH/gm.), mineral oil solution of polymethyl methacrylate and phosphosulphurized alpha-pinene and (b) dinonyl sebacate (acidity 0.05 mg. KOH/gm.), polybutyl methacrylate and phenthiazine.ALSO:A lubricating composition (see Group III) comprises a dialkyl ester of a saturated dicarboxylic acid together with a polymer or a complex ester soluble in the dialkyl ester, the viscosity of the composition being greater than that of the dialkyl ester and the acidity of the dialkyl ester being less than 0.3 mg. KOH/gm. Complex esters mentioned are as follows: (1) esters of the formula R1OOC.R2.COOR3.OOCR4.COOR5 (some of which are described in Specifications 666,697, 687,346 and 687,347) where R1 and R5 are aliphatic alcohol or ether alcohol residues, R2 and R4 are the hydrocarbon radicles of aliphatic dicarboxylic acids and R3 is the hydrocarbon or oxygenated hydrocarbon radicle of a glycol or a polyglycol, all the radicles R1-R5 being saturated; (2) esters (including those described in Specification 668,663) formed by fully esterifying a dicarboxylic acid R(COOH)2 (where R is a hydrocarbon radicle containing 0-26 carbon atoms or an organic radicle consisting of a series of saturated aliphatic hydrocarbon radicles linked by at least one non-carbon atom chosen from the elements oxygen and sulphur, the total number of carbon atoms and said non-carbon atoms in the radicle being 3-80, there being at least 2 carbon atoms between each pair of said non-carbon atoms and a total of not more than 2 sulphur atoms) with a hydroxy ester of the formula <FORM:0711211/IV (b)/1> where R1 is either an aliphatic hydrocarbon radicle containing 1-22 carbon atoms or a radicle containing 2-22 carbon atoms and consisting of two aliphatic hydrocarbon groups interlinked by one atom of oxygen or sulphur, R11 is either an aliphatic hydrocarbon radicle containing 1-20 carbon atoms or a radicle consisting of a series of saturated aliphatic hydrocarbon radicles (each having at least 2 carbon atoms) linked through 1-5 non-carbon atoms chosen from the elements oxygen and sulphur so that the total number of carbon atoms and said non-carbon atoms is 4-20 and the total number of sulphur atoms is not more than 2, R1, R2, R3 and R4 are each chosen from hydrogen, methyl and ethyl, m is an integer from 1 to 20 and n is 1 or 2; (3) esters (including those described in Specification 664,992) of formula <FORM:0711211/IV (b)/2> where R1 is an aliphatic hydrocarbon group which may contain one or more hydroxyl groups, R is an aliphatic hydrocarbon group, R11 is hydrogen or an alkyl or alkylene group containing not more than 6 carbon atoms, R111 is hydrogen or a methyl group, m is an integer from 1 to 3, n is an integer and x is an integer from 1 to 30; (4) esters (including those described in Specification 662,650) of formula R11OOCRCOOR1OOCR111 and prepared by reacting 1 mol. of a dibasic acid with one mol. of a glycol in such a manner that a half ester is formed and esterifying the terminal OH and COOH groups with a monobasic acid and a monohydric alcohol respectively; and (5) esters (including those described in Specification 659,103) of formula R2COOR1OOCR3COOR11OOCR12 and prepared by reacting, under esterification conditions, 2 mols. of a monobasic aliphatic acid with 2 mols. of a glycol and 1 mol. of a dibasic aliphatic or aromatic acid.  The blend of a complex ester with a dialkyl ester of a saturated dicarboxylic acid may be made mechanically, or it may be made chemically as described in Provisional Specification 683,803 and in Specification 687,347. The complex ester may also be of the prescribed low-acidity and the esters may be treated separately to lower their acidity to the prescribed value or the blend may be so treated.  Methods described and exemplified for reducing acidity are (a) treatment of the esters with alumina, fuller's earth, attapulgus clay, charcoal or other solid adsorbents; (b) treatment of the esters with aqueous or dry alkali such as sodium carbonate, aqueous sodium carbonate preferably being used in presence of isopropyl alcohol, and optionally being followed by treatment (a); (c) prolongation of the esterification reaction in the preparation of the esters; (d) treatment of the esters with anion exchange resins such as m-phenylene diamine-formaldehyde resins; and (e) treatment with a mixture of solid adsorbent and dry alkali such as sodium carbonate. Specification 600,325 also is referred to.ALSO:A lubricating composition, of sufficiently low corrosivity to permit its use in the lubrication of prop-jet engines, comprises a dialkyl ester of a saturated dicarboxylic acid together with a polymer or a complex ester soluble in the dialkyl ester, the viscosity of the composition being greater than that of the dialkyl ester and the acidity of the dialkyl ester being less than 0.3 mg. KOH/gm.  The complex esters referred to are defined as esters containing in the molecule more than 3 monocarboxylic acid, monohydric alcohol, polycarboxylic acid or polyhydric alcohol residues, and in which there is at least one polyhydric alcohol and one polycarboxylic acid residue, each of which has at least two of its functional groups.  They are formed by the esterification, in one or more stages, of mixtures of polycarboxylic acids and polyhydric alcohols with or without monocarboxylic acids, monocarboxylic acids and monohydric alcohols, or monohydric alcohols. The various types of suitable complex esters are discussed (see Group IV (b)) and they include the complex esters of Specifications 659,103, 662,650, 664,992, 666,697, 668,663, 687,346, and 687,347. Polymers mentioned are polyolefins, polymerized unsaturated esters, copolymers of olefins and aromatic hydrocarbons with unsaturated side chains, copolymers of two or more unsaturated esters, and mixtures of such polymers.  The lubricating composition may contain additional ingredients such as dyes, antioxidants, detergents, mineral and synthetic hydrocarbon oils, and other synthetic lubricating oils such as those of the polyglycol ether type.  Methods of reducing the acidity of the dialkyl ester of a saturated dicarboxylic acid to the prescribed value are described (see Group IV (b)) and it is stated that the acidity of the complex ester may similarly be reduced.  If desired, the acidity may be reduced only after the formation of the lubricating composition.  Although primarily intended for aviation turbine lubricants, the lubricating compositions may also be employed as motor lubricants, as recoil oils and hydraulic fluids, for example in gun control mechanisms, as lubricants and working fluids for precision tools and as electrical oils.  In the examples, lubricating compositions are described consisting of (a) dinonyl sebacate of acidity 0.07mg. KOH/gm., mineral oil solution of polymethyl methacrylate and phosphosulphurized alpha-pinene, (b) dinonyl sebacate of acidity 0.05mg. KOH/gm., polybutyl methacrylate and phenthiazine and (c) dinonyl sebacate of acidity 0.07mg. KOH/gm., complex ester of acidity 0.05mg. KOH/gm. and phenthiazine.  The complex ester of example (c) is one prepared by esterifying 1 mol. of crude polyethylene glycols, having a mean molecular weight approximating to that of tetraethylene glycol, with 2 mols. of sebacic acid and then esterifying the half ester thus formed with 2 mols. of 2-ethyl-hexanol.  Specifications 600,325 and 683,803 also are referred to.