The present disclosure relates to viscosity index modifiers that have dispersant properties and lubricating oil compositions comprising said viscosity index modifiers. The viscosity index modifier is the reaction product of an acylated olefin copolymer, a polyamine, and a dicarboxylic acid or anhydride thereof that can react with a free primary amine of the polyamine to form a ring moiety. The disclosure also relates to the use of lubricant compositions comprising the viscosity index improvers of the disclosure for improving the soot or sludge handling characteristics of an engine lubricant composition, while minimizing the deterioration of engine seals.

The invention relates to the field of lubricants and provides a lubricating composition comprising at least one base oil, the kinematic viscosity of which measured at 40 C. does not exceed 10 mm.sup.2/s and the pour point of which does not exceed 50 C., and at least one thickener, said lubricating composition having a pour point not exceeding 55 C.

A composition comprising an oil of lubricating viscosity and a compound represented by formula (I) wherein x is 0 or 1 and R.sup.1 is a hydrocarbyl group containing about 4 to about 18 carbon atoms, which composition is effective at swelling seals. ##STR00001##

A fully-formulating lubricating composition comprising an oil of lubricating viscosity; an ionic tetrahedral borate compound including a tetrahedral borate anion having a boron atom with two bidentate di-oxo ligands both being a linear C18-tartrimide; a first dispersant comprising a conventional ammonium substituted polyisobutenyl succinimide compound having a polyisobutenyl number average molecular weight of 750 to 2,500; a second dispersant comprising an ammonium substituted polyisobutenyl succinimde compound having an N:CO ratio of 1.8 and a polyisobutylenyl number average molecular weight of 750 to 2,500, wherein one or more of the first dispersant and the second dispersant are in cationic form. The fully formulated lubricating composition including one or more performance additives.

The present invention provides a lubricating oil composition for automatic transmissions which comprises: 55 to 85 mass % of a Fischer-Tropsch synthetic oil with a kinematic viscosity at 100 C. of 2 to 4 mm2/s as a low-viscosity base oil; 1 to 10 mass % of an olefin copolymer 5 with a kinematic viscosity at 100 C. of 150 to 1,000 mm2/s as a high-viscosity base oil; and a polymethacrylate with a weight-average molecular weight of 10,000 to 50,000. This lubricating oil composition is such that the viscosity index of the composition is not 10 less than 190, the Brookfield viscosity is not more than 6,000 mPa.Math.s at low temperature (40 C.), the kinematic viscosity at 100 C. is 6 to 7 mm2/s, and the rate of reduction of the kinematic viscosity after a KRL shear stability test (60 C., 20 hr) is kept to within not more 15 than 3%.

The invention relates to a seal swell agent which is a substituted sulfonyldibenzene compound, and lubricating compositions containing the seal swell agent. The substituents on the benzene rings may be hydrocarbyl groups of 4 to 20 carbon atoms or alkylene groups of 1-2 carbon atoms with further functional groups.

The disclosed technology relates to lubricants for compression ignition internal combustion engines, particularly those demonstrating at least one of improved seals performance, reduced deposit formation, and excellent durability. The present invention provides a low zinc lubricating composition comprising (a) an oil of lubricating viscosity, (b) a borated dispersant, and (c) a metal-free organo-phosphorus anti-wear additive, wherein the lubricating composition is substantially free of a metal containing sulfur coupled alkyl phenol compound. Further, the low zinc lubricating composition contains zinc in an amount less than 600 ppm by weight of the composition.

The invention relates to industrial gear oil compositions that have been specially designed to have improved storage stability and/or paint compatibility and/or seal compatibility. This improvement is achieved while maintaining good performance in other areas. These improvements are particularly relevant to synthetic lubricants, such as those made with polyalphaolefin (PAO) base oils. This balance of properties has been difficult to achieve in synthetic compositions where problems in the areas of storage stability, paint compatibility and/or seal compatibility of become more pronounced. The invention also relates to processes of making such compositions and methods of using the same.

The invention relates to a seal swell agent which is a substituted sulfonyldibenzene compound, and lubricating compositions containing the seal swell agent. The substituents on the benzene rings may be hydrocarbyl groups of 4 to 20 carbon atoms or alkylene groups of 1-2 carbon atoms with further functional groups.

A silicone oil having a mean molecular weight average greater than about 20,000 Daltons, with no more than about 3% to about 4% of the total silicone oil by weight being comprised of components having a molecular weight less than about 15,000 Daltons. In some embodiments, the silicone oil is used in intraocular lens devices.