The present invention relates to hydrogenated linear copolymers comprising butadiene and isoprene monomer units, as well as the process for preparing these copolymers. The invention further relates to a lubricating oil composition comprising one or more hydrogenated linear copolymers according to the invention, as well as to the use of the aforementioned copolymers as a lubricant additive or a synthetic base fluid for lubricant compositions, especially in gear oils, transmission oils, hydraulic oils, engine oils, grease, marine oils or industrial lubricating oils.

A mixed composition including a refrigerant including at least one unsaturated fluorinated hydrocarbon compound selected from the compound having a formula C.sub.xF.sub.yH.sub.z, x is an integer of 2 to 6, y is an integer of 1 to 11, z is an integer of 1 to 11, and the compound has at least one unsaturated carbon-carbon bond, and a refrigerator oil including a base oil (A); a phosphorus-based extreme pressure agent (B); a decomposition inhibitor (C) that inhibits the decomposition of the unsaturated fluorinated hydrocarbon in the presence of an iron; and an antioxidant (D), wherein (C) controls the amount of fluorine in the refrigerator oil composition at 30 ppm by mass or less after mixing the refrigerator oil with R1234yf at a mass ratio of 1:1, and subjecting the mixture to an autoclave test at 175° C. for 336 hours with a metal catalyst including iron, copper, and aluminum.

Aspects of the present disclosure relate to a process for producing synthetic hydrocarbon base oils having advantageous properties for formulation of engine oils, and the base oils obtained by such processes, involving the production of branched alkenes from the oligomerization of C14-C18 olefins. According to one embodiment, the base oils are obtained by first forming a mixture of two or more olefins ranging from C14-C18, where one of the olefins is an alpha olefin and the other has an average double bond position between 1.5-5.0, and oligomerizing this mixture in the presence of a catalyst to form one or more branched alkenes, hydrogenating the branched alkenes, and fractionating to form base oils. According to one aspect, advantageous properties can be obtained by controlling one or more of the degree of branching, branch length, branching positions, selection of the C14-C18 olefins, and catalytic isomerization, during or after the oligomerization process.

The present invention relates to a lubricating oil composition containing: (A) a poly-α-olefin base oil obtained by using a metallocene catalyst; (B) a mineral oil-based base oil exhibiting a distillation curve with a temperature gradient Δ|Dt| of distillation temperature between two points 2.0 vol % and 5.0 vol % of distillation amount being 6.8° C./vol % or less; and (C) an ester-based base oil in an amount of 6% by mass or more based on a total amount of the composition.

This disclosure relates to base stocks comprising a C28-C32 hydrocarbon fraction and optionally a C42-C48 hydrocarbon fraction produced by dimerization and trimerization of a linear C14 mono-olefin, a linear C16 mono-olefin, or a mixture thereof, in the presence of a Lewis acid, oil compositions comprising such base stock(s), and processes for making such base stocks.

A constant velocity joint having a boot constructed from a thermoplastic polyether ester as the boot material. The boot includes a lubricating grease composition for lubricating the constant velocity joint, the lubricating grease composition comprising calcium lignin sulfonate.

An automotive axle includes a housing including gears and a bath lubricating the gears, the bath including gear oil and about 0.1 to 5 wt. % secondary alcohol ethoxylate based on total weight of the bath such that during automotive operation at temperatures less than a threshold, reverse micelles form to trap air bubbles in the bath, emulsifying the bath, and at temperatures greater than the threshold, the reverse micelles dissipate.

A multi-grade lubricating oil including a (meth)acrylate polymer with at least two distinct molecular weight arms and a blend of heavier and lighter base oils with increased amounts of the heavier base oil to achieve SAE grade performance. The compositions herein achieve SAE certifications as lower CCS viscosities at target kinematic viscosities for multi-grade oils.

A lubricating oil composition may include a base oil (A), succinimide (B) which has not been modified with boron, succinimide (C) modified with boron, a metallic detergent (D), and an antioxidant (E), wherein the ratio of the content of boron atoms derived from ingredient (C) to the content of nitrogen atoms derived from ingredients (B) and (C), B/N, is 0.30 or less by mass, the lubricating oil composition satisfying requirement (I) and/or requirement (II). Requirement (I): Ingredient (D) includes a metallic detergent (D1) having a base value less than 100 mgKOH/g. Requirement (II): Ingredient (E) includes an amine-based antioxidant (E1), the content of ingredient (E1) being 1.00 mass % or less.

A lubricating oil composition containing a base oil (A), a comb-shaped polymer (B), and an olefin-based copolymer (C), wherein a content of the component (B) is more than 0.80 mass % based on the total amount of the lubricating oil composition, a weight average molecular weight of the component (C) is 500,000 or more, and the lubricating oil composition has a viscosity index of 200 or more and a kinematic viscosity at 100° C. of 9.3 to 11.0 mm.sup.2/s.