A composition comprising water, a glycol, and a polyalkylene glycol which has a biodegradability of at least 60% as determined using OECD 301F wherein the composition has a kinematic viscosity of at least 25 mm.sup.2/sec at 40° C. is useful as a rheology modifier, particularly in subsea applications. In some instances, the composition comprises 10 to 65 weight % water, 20 to 60 weight % of a glycol selected from ethylene glycol, diethylene glycol, triethylene glycol and tetra ethylene glycol, 10 to 40 weight % of a polyalkylene glycol, and 0 to 10% of additives based on total weight of the composition wherein the polyalkylene glycol has a—molecular weight of no more than 4000 g/mol and is characterized in that it is an oxyethylene/oxypropylene block copolymer having a weight percent of oxyethylene of at least 20% based on total weight of the copolymer.

Proposed is a process of producing a high-quality lube base oil using a refined oil fraction obtained from waste lubricant as a feedstock. The process includes purifying waste lubricant to obtain a refined oil fraction, pretreating the refined oil fraction, and blending the pretreated refined oil fraction with unconverted oil (UCO), before or after vacuum distillation and catalytic dewaxing of the unconverted oil, or between the vacuum distillation and the catalytic dewaxing of the unconverted oil.

The present invention aims to provide a viscosity index improver composition and a lubricating oil composition having a low HTHS viscosity at 100° C., an excellent shear stability, and an excellent low temperature viscosity. The present invention relates to, for example, a viscosity index improver composition (C), containing: a copolymer (A) containing a polyolefin-based monomer (a) represented by the following formula (1) as a constituent monomer; a copolymer (B) containing a (meth)acrylic acid alkyl ester (c) having a C12-C15 straight-chain or branched alkyl group and a (meth)acrylic acid alkyl ester (d) having a C16-C20 straight-chain or branched alkyl group as constituent monomers; and a base oil, wherein a weight average molecular weight ratio {(A)/(B)} of the copolymer (A) to the copolymer (B) is 2 to 55, and a weight ratio (A/B) of the copolymer (A) to the copolymer (B) constituting the viscosity index improver composition (C) is 5 to 100:

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A lubricant composition that comprises a hydrocarbon base oil, a polar viscosity improver; and an esterified polyalkylene glycol: R.sup.1[O(R.sup.2O).sub.n(R.sup.3O).sub.m(C═O)R.sup.4].sub.p, wherein R.sup.1 is a linear alkyl having 1 to 18 carbon atoms, a branched alkyl having 4 to 18 carbon atoms or an aryl with 6 to 30 carbon atoms; R.sup.2O is an oxypropylene moiety derived from 1, 2-propylene oxide; R.sup.3O is an oxybutylene moiety derived from butylene oxide, wherein R.sup.2O and R.sup.3O are in a block or a random distribution; R.sup.4 is a linear alkyl with 1 to 18 carbon atoms, a branched alkyl with 4 to 18 carbon atoms or an aryl with 6 to 18 carbon atoms; n and m are each independently integers ranging from 0 to 20 wherein n+m is greater than 0, and p is an integer from 1 to 4. The lubricant composition may have a viscosity index of at least 150, a kinematic viscosity at 100° C. from 2 to 5 centistokes and a kinematic viscosity at −20° C. of at most 600 centistokes.

A polymer surfactant for improving engine oil emulsion properties of a lubricating composition mixed with water and/or fuel contamination, particularly at very cold temperatures, is described herein. In approaches, selected polymeric and functionalized compounds can impart both robust emulsion properties and simultaneously deliver good low temperature fluidity for lubricating compositions that may contain residual amounts of water and/or fuel contamination. Lubricating compositions including such surfactants demonstrate robust properties at temperatures down to about −30° C.

Disclosed is a lubricant composition including: at least one base oil; at least one polyalkylene glycol with at least 50% by weight of butylene oxide units and having a kinematic viscosity, measured at 100° C. according to standard ASTM D445 (2015), which is greater than or equal to 50 mm2/s, a kinematic viscosity, measured at 40° C. according to standard ASTM D445 (2015), which is greater than or equal to 1000 mm2/s and a Viscosity Index, measured according to standard ASTM D2270 (2012), which is greater than or equal to 180. Also disclosed is the use of such a composition for transmission or gear lubrication.

The present invention relates to a hydraulic fluid composition containing a base oil (A), an antioxidant (B) including an amine-based antioxidant (B1) and a phenol-based antioxidant (B2), and a succinimide-based compound (C), wherein the hydraulic fluid composition satisfies the following requirement (I); and is to be used for hydraulic equipment which is equipped with at least one of a wet type brake and a wet type clutch and which is selected from a construction machinery, a general industrial machinery, and a power generator, and in which a working pressure is 30 MPa or more. The hydraulic fluid composition is not only excellent in wear resistance and an effect for suppressing the sludge formation but also excellent in a braking performance or a clutch performance, even when used under a high-pressure condition. Requirement (I): A static friction coefficient (μ.sub.s) after 1,000 cycles, as measured in conformity with the SAE No. 2 test described in JCMAS P 047:2004, is 0.100 to 0.162.

A refrigerating oil comprising a lubricating base oil, a first extreme pressure agent containing sulfur and phosphorus as constituent elements and a second extreme pressure agent containing phosphorus but not containing sulfur as constituent elements, and having a kinematic viscosity at 100° C. of 0.5 mm.sup.2/s or more and 2.5 mm.sup.2/s or less.

Use of a gasoline fuel composition for reducing the occurrence of Low Speed Pre-Ignition (LSPI) in a spark-ignition internal combustion engine, wherein the gasoline fuel composition comprises a gasoline base fuel and has a PM Index of 1.4 or less.

The present invention provides a lubricant composition comprising a base oil of lubricating viscosity, wherein the base oil comprises an ether base stock of formula (A), where: R.sub.a and R.sub.b are aliphatic hydrocarbyl groups and may be the same or different; the lubricant composition further comprising at least one aminic anti-oxidant and at least one phenolic anti-oxidant. In some embodiments, the ether base stock has the formula (1), where: R.sub.1 R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are as defined herein. The lubricant composition may be used for lubricating a surface in an internal combustion engine as well as for improving the fuel economy performance and/or piston cleanliness performance of an engine and/or a vehicle, such as an automotive vehicle associated with an internal combustion engine. ##STR00001##