Sulfur-free, ashless, and low phosphorus-containing lubricant compositions for use as engine oil having improved oxidation stability. The lubricant composition can include about 60.0 mass % to about 99.8 mass % of an oil base stock, at least one ashless antiwear additive, at least one ashless detergent, and at least one antioxidant, based on a total mass of the lubricant composition. The oil base stock can include at least one polyalphaolefin and at least one alkyl naphthalene. The lubricant composition can contain less than about 0.05 mass % phosphorus, less than about 0.05 mass % sulfur, and less than about 0.05 mass % ash. The lubricant composition can be made by a process that includes combining the above-mentioned components to provide a lubricant composition.

The invention is directed to a method for reducing low speed pre-ignition events in a spark-ignited direct injection internal combustion engine by supplying to the sump a lubricant composition which contains an oil of lubricating viscosity and a metal overbased detergent. The metal overbased detergent may be selected from sulfonate detergents, phenate detergents, and salicylate detergents, especially sulfonate detergents with a metal ratio of at least 5.

The engine lubricating system can become contaminated with carbon deposits and sludge. Sludge is where the combustion by-products that have entered the oil base saturate this oil base, thus forming a thick carbon rich substance. Sludge is not wanted within the engine. Sludge and or carbon deposits in the motor oil cause problems. Such carbon deposits form in the motor oil from heat, pressure, and namely combustion gases that have leaked pasted the piston rings. Turpentine and terpenes, hereafter referred to as “terpenes”, have shown that these chemicals can breakdown carbon which has been deposited within the engine's oil base.

The present invention relates to a lubricating composition, intended for a refrigerant system comprising a gas compression circuit, comprising:

at least one first polyalkylene glycol exhibiting a hydroxyl number strictly of greater than 50 mg KOH/g and a kinematic viscosity, measured at 100° C. according to the standard ASTM D445, ranging from 5 to 10 mm.sup.2/s, and

at least one second polyalkylene glycol with a kinematic viscosity, measured at 100° C., ranging from 100 to 500 mm.sup.2/s,

said polyalkylene glycols A and B being present in a PAG(s) A/PAG(s) B ratio by weight of between 60/40 and 99/1.

It also relates to the employment of such a lubricating composition in a refrigerant system comprising a gas compression circuit, in particular for an automobile air conditioning system, in combination with a coolant based on hydrocarbon compounds, such as R134a and/or HFO-1234yf.

The present invention relates to a lubricating composition comprising a base oil and an antioxidant additive, said antioxidant additive comprising a phenolic antioxidant, an amine antioxidant, and a tocopherol supplement comprising at least one member of the list consisting of: beta-tocopherol, delta-tocopherol and gamma-tocopherol.

The present invention also relates to a use of a lubricating composition according to the invention, in a combustion engine.

The present disclosure provides A lubricant composition comprises an antioxidant; 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, wherein the antioxidant is present in an amount by weight of at least 0.5% to 20% based upon the weight of the antioxidant and the esterified polyalkylene glycol and the antioxidant is soluble in the esterified polyalkylene glycol in an amount of at least 0.5% by weight. The lubricant composition may be used as an additive to form a hydrocarbon lubricant composition.

A transformer oil basestock is disclosed that includes at least 99 wt % of naphthenes and paraffins, based on the total weight of the transformer oil basestock, wherein the weight ratio of naphthenes to paraffins is at least 1, as measured by GC-MS, and wherein the paraffins consist essentially of isoparaffins, as determined by GC-FID. In addition, a transformer oil composition is disclosed that includes the transformer oil basestock, an anti-gassing agent and an antioxidant.

The invention is directed to a method for reducing low speed pre-ignition events in a spark-ignited direct injection internal combustion engine by supplying to the sump a lubricant composition which contains an oil of lubricating viscosity and an ashless dispersant. The ashless dispersant may be selected from succinimide compounds prepared from aliphatic or aromatic amines.

The lubricating oil composition includes a base oil and a fullerene adduct.

The present disclosure provides compounds of formula (I), and preparation method thereof, ##STR00001## wherein W is independently selected from the group consisting of H, F, Cl, Br and I; X is independently selected from the group consisting of H, F, Cl, Br, I, CW.sub.3 and OR on the basis that at least one X is OR; R is independently selected from the group consisting of C(O)CH.sub.2).sub.m(CF.sub.2).sub.nY and CW.sub.2C(CW.sub.2OC(O)(CH.sub.2).sub.m(CF.sub.2).sub.nY).sub.3; m is an integer from 0 to 2;15 n is an integer from 2 to 8; Y is C(Z).sub.3; and Z is independently selected from the group consisting of H, F, Cl, Br and I. Such compounds may be utilised as lubricants, for example in heat transfer compositions.