Patent GB-758436-A (GB)
Title: Phosphosulphurisation of complex esters
Inventor: HOARE MICHAEL FREDERICK
IPC: C07F9/04
Filed: 1952-09-03
Abstract: The invention comprises as a new compound the product obtained by reacting a complex ester with one or more phosphorus sulphides or with an elemental mixture of phosphorus and sulphur or with phosphorus and sulphur (or sulphur and phosphorus) in turn at an elevated temperature which is less than that leading to sludge and tar formation.  The complex esters are defined as esters containing three or more carboxylic ester groups in a linear arrangement, there being present at least one polybasic acid residue.  They include particularly those formed by the esterification, in one or more stages, of mixtures of dibasic acids, dihydric alcohols and monobasic acids and/or monohydric alcohols.  Suitable complex esters include those disclosed in Specifications 659,103, 662,650, 666,697 and 668,663.  Specified phosphorus sulphides are phosphorus pentasulphide and P4S3.  The reaction temperature when phosphorus pentasulphide is used is preferably 370-390 DEG  F.  The complex ester can also first be reached with sulphur, if desired in the presence of a sulphurization catalyst, e.g. a rubber vulcanization accelerator, and then with phosphorus.  The products may be purified by filtration, adsorbent treatment, steam or vacuum stripping or solvent extraction. Suitable adsorbents are clay or other activated earth, activated carbon, silica gel and alumina fines.  The amount of phosphosulphurization material used is preferably below 20 per cent, e.g. between 5 and 15 per cent by weight of the complex ester.  In an example a complex ester formed by the reaction under esterification conditions of 2 mols. of 3,5,5-trimethyl hexanol, 2 mols. of sebacic acid and 1 mol. of polyglycol 200 is heated with 6 per cent of its weight of phosphorus pentasulphide to 385 DEG  F.  The product is decanted and filtered and tables are given to show the potency of the product as an extreme pressure additive and as an anti-oxidant additive for various hydrocarbon oil and synthetic ester lubricants (see Group III).  Specifications 687,346, [Group III], 687,347, 687,348, 711,211; 743,571 and 756,427, [both in Group III], also are referred to.ALSO:A lubricating composition comprises a lubricating oil containing dissolved therein a minor proportion by weight e.g. 0.1 to 15 per cent, of a product obtained by reacting a complex ester with one or more phosphorus sulphides or with an elemental mixture of phosphorus and sulphur or with phosphorus and sulphur (or sulphur and phosphorus) in turn at elevated temperature but at a temperature less than that leading to sludge and tar formation (see Group IV(b).  The complex esters are defined as esters containing three or more carboxylic ester groups in a linear arrangement there being present at least one polybasic acid residue.  They include particularly those formed by the esterification, in one or more stages, of mixtures of dibasic acids, dihydric alcohols, and monobasic acids and/or monohydric alcohols.  Suitable complex esters include those disclosed in Specifications 659,103, 662,650, 666,697 and 668,663.  Specified lubricating oils are mineral lubricating oils and oxygenated lubricating oils which may be synthetic esters such as complex esters, diesters and simple esters, and ether oils such as polyethylene glycol mono- or di-alkyl ethers.  Natural glyceride oils are also referred to.  Conventional additives such as dyes, antioxidants, detergents, corrosion inhibitors, oliness agents and extreme pressure agents may also be present.  In an example a complex ester obtained by the reaction under esterification conditions of 2 moles of 3, 5, 5-trimethyl hexanol, 2 moles of sebacic acid and 1 mole of polyglycol 200 is heated with phosphorus pentasulphide to 385 DEG F. and tables are given to show the potency of the product as an extreme pressure additive in hydrocarbon and synthetic ester lubricants, the latter being either dioctyl adipate or a blend of a complex ester from sebacic acid, polyglycol 200 and 2-ethyl hexanol, with dimonyl sebacate. Tests are also described to show that the additive has good antioxidant properties and little corrosive effect on copper when added to an ester blend comprising dioctyl adipate and a complex ester formed from 2 moles 2-ethyl hexanol, 2 moles of sebacic acid and 1 mole polyglycol 200.  Specifications 687,346, 687,347, 687348, 711,211, 743,571 and 756,427 also are referred to.