Patent GB-1131926-A (GB)
Title: Improvements in or relating to ester-based lubricants
Inventor: BARCROFT FRANCIS TERRANCE
IPC: C10M169/04
Filed: 1967-03-10
Abstract: 1,131,926. Lubricants. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. 10 March, 1967, No. 11401/67. Heading C5F. A lubricant comprises a major proportion of an ester lubricating oil and minor proportions of (a) a reaction product of a polyamine (as defined) with a succinic acid (or a functional derivative thereof) having, as a substituent on an alpha carbon atom, an aliphatic hydrocarbon group containing from 30-200 carbon atoms, and (b) an ester lubricating oil-soluble copolymer having at least one hydroxy group and first ester groups derived from an alkenoic acid and a C 4-30  alkanol and second ester groups derived from an alkenoic acid and an alkanpolyol. The ester oil is preferably a diester of the formula R 1 OOC.R.COOR 2 , wherein R is a divalent saturated aliphatic hydrocarbon radical preferably having 1-18 carbon atoms and R 1  and R 2  are alkyl, aralkyl or cycloalkyl radicals of more than 2, preferably 4-20 carbon atoms, but diesters of polyols and saturated monocarboxylic acids may also be suitable. The ester oil may be used as mixtures and may contain a minor proportion of one or more mineral oils. The polyamine additive (a) is an amide, diamide, imide, diimide or a mixture thereof formed from the succinic acid reactant, which preferably has a polymer of a C 2-5  olefin as the aliphatic hydrocarbon group, and the polyamine, or a mixture of polyamines having the general formula NH 2 R<SP>1</SP>(NHR<SP>2</SP>) n .NR<SP>3</SP>R<SP>4</SP> wherein R<SP>1</SP> and R<SP>2</SP> are alkylene or alkyl substituted alkylene radicals containing up to 7 carbon atoms, R<SP>3</SP> and R<SP>4</SP> are hydrogen atoms, alkyl groups containing up to 7 carbon atoms, or amino-substituted alkyl groups, and n is 0 to 5. The additive (b) has an average molecular weight of 100,000-2,000,000 (as found by light scattering) and preferably has the first ester groups derived from an alkenoic acid and a C 12-30  alkanol. Suitable copolymers are made by copolymerizing e.g. lauryl methacrylate, stearyl methacrylate and 2-hydroxyethyl methacrylate in the mole ratio of 5: 5: 4 respectively but can also be made by reacting an intermediate copolymer of an alkenoic acid and alkyl esters of alkenoic acids with an alkylene oxide. Other additives include: (c) metal dithiophosphates, preferably zinc dialkyldithiophosphates, but dithiophosphates having aryl, alkaryl, cycloalkyl and alkoxy-alkyl, may also be used; (d) neutral, preferably basic, polyvalent metal petroleum sulphonates, preferably of alkaline earth metals; (e) neutral, preferably basic, salts of metals of Group IIA of the Periodic Table and condensation products of a hydrocarbon substituted phenol, containing at least 4 carbon atoms in the substituent, with formaldehyde or acetaldehyde or a polymer thereof; (f) oil-soluble polymers of esters, such as of alkyl esters of acrylic acid or a 1-alkyl acrylic acid and optionally polar monomers such as vinyl pyridines and vinyl pyrrolidones, as thickeners; (g) oil-soluble basic polyvalent metal, preferably alkaline earth metal, salts of aromatic carboxylic acids; anti-oxidants such as aromatic amines and phenols; extreme pressure agents such as triaryl phosphates and phosphorothionates and amine salts of halogenated substituted phosphonic acids and simple metal phenates such as calcium phenate. The additives a-g may be used in the amounts by weight 0À1-20% of (a), 0À1-30% of (b), 0À01-5% of (c), 0À01-10% of (d), 0À01-10% of (e), 0À1-30% of (f) and 0À1-20% of (g).