The present disclosure relates to polysiloxanes, processes for preparing polysiloxanes, and hydraulic fluids comprising polysiloxanes. This disclosure also relates to hydraulic fluids comprising one or more polysiloxane compounds and diphosphonate compounds, and to the use of diphosphonate compounds in hydraulic fluids or as additives or components in various compositions, for example to provide fire retardant properties to a fluid or composition. This disclosure also relates to use of the compositions as hydraulic fluids, which may be used in various machines, vehicles and craft, including aircraft.

Provided is a lubricant composition comprising a lubricant base oil (A), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D), and a secondary amine compound (E), and having a flash point of 172° C. or higher.

The present invention provides an electrorheological fluid, which includes a dielectric particle, a conductor particle and insulating oil, and the dielectric particle is evenly dispersed in the insulating oil; wherein the conductor particle is evenly dispersed in the insulating oil or inlaid in an interior and on a surface of the dielectric particle. The electrorheological fluid has the advantages of high shear stress, long service life, good temperature stability and small leakage current.

A lubricating oil composition contains a base oil (A), a zinc dithiophosphate (B), and a sarcosine compound (C), the composition having a content of the sarcosine compound (C) of more than 0.05% by mass and 0.40% by mass or less based on the entire amount of the lubricating oil composition, and satisfying requirement (α) or (β):

Requirement (α): when the content of the sarcosine compound (C) is more than 0.05% by mass and less than 0.20% by mass based on the lubricating oil composition, one or more phosphorus compounds (D) selected from an acidic phosphoric acid ester (D1) and an amine salt thereof (D2) are optionally contained;

Requirement (β): when the content of the sarcosine compound (C) is 0.20% to 0.40% by mass based on the lubricating oil composition, the phosphorus compound (D) is contained in an amount less than 0.50% by mass based on the lubricating oil composition.

A composition comprising water and a polyalkylene glycol having an allyl content of less than 20 ueq/g, which composition has reduced foaming properties and preferably a biodegradability of at least 60% as determined using OECD 301F. The polyalkylene glycol can be made by forming a first intermediate comprising an oxypropylene block by reacting propylene oxide with a polyol initiator in the presence of a Double Metal Cyanide catalyst, and then reacting the first intermediate with ethylene oxide in the presence of a KOH catalyst.

Provided are a lubricant composition for shock absorbers, a lubricant additive, and a method of adjusting frictional property of a lubricant composition for shock absorbers, each capable of satisfying both the steering stability and ride comfort. The lubricant composition for shock absorbers contains a base oil and pentaerythritol esters and having frictional property represented by the following formula (1):

[00001]$\begin{array}{cc}\text{RI}\text{>}\text{1}\text{.75}\times {\text{F}}_{\text{ave}}\text{-}\text{0}\text{.05}& \text{­­­(1)}\end{array}$

supposing that a ratio ({F.sub.sa - F.sub.ave} / F.sub.ave) of a difference, at the time of minute amplitude, between a peak frictional force F.sub.sa in transition from a stationary state to a sliding state and an average frictional force F.sub.ave to the average frictional force F.sub.ave at the time of minute amplitude is responsiveness RI.

The present invention aims to provide a viscosity-index improving agent capable of providing a lubricating oil composition having an appropriate gelation index, an excellent HTHS viscosity at 100° C., and an excellent kinematic viscosity at 40° C. when the viscosity-index improving agent is added thereto. The present also aims to provide a lubricating oil composition containing the viscosity-index improving agent. The present invention relates to, for example, a viscosity-index improving agent containing a copolymer (A) and an ester oil (Z), the copolymer A containing, as constituent monomers, a polyolefin-based monomer (a) represented by the following formula (1), a monomer (b) represented by the following formula (2) in which R.sup.4 is a C4 alkyl group, and at least one of a monomer (c) represented by the following formula (3) and a monomer (d) represented by the following formula (2) in which R.sup.4 is a C2-C3 alkyl group:

##STR00001##

wherein R.sup.1 is a hydrogen atom or a methyl group; —X.sup.1— is a group represented by —O—, —O(AO).sub.m—, or —NH—, A is a C2-C4 alkylene group, m is an integer of 1 to 10, and each A may be the same or different when m is 2 or more; R.sup.2 is a residue after removal of one hydrogen atom from a hydrocarbon polymer containing a 1,2-butylene group as a structural unit; and p represents a number of 0 or 1;

##STR00002##

wherein R.sup.3 is a hydrogen atom or a methyl group; —X.sup.2— is a group represented by —O— or —NH—; and R.sup.4 is a C2-C4 alkyl group;

##STR00003##

wherein R.sup.5 is a hydrogen atom or a methyl group; —X.sup.3— is a group represented by —O— or —NH—; R.sup.6 is a C2-C4 alkylene group; R.sup.7 is a C1-C8 alkyl group; and r is an integer of 1 to 20, and each R.sup.6 may be the same or different when r is 2 or more.

The invention relates to acrylate-olefin copolymers and to a method for preparing these polymers. The present invention is also directed to lubricant compositions comprising these copolymers, and to the use of these copolymers as a lubricant additive or a synthetic base fluid in a lubricating oil composition, preferably in a gear oil composition, a transmission oil composition, a hydraulic oil composition, an engine oil composition, a marine oil composition, an industrial lubricating oil composition or in grease.

A process is disclosed for producing renewable products, such as a renewable base oil, from a feedstock of biological origin. The process includes subjecting a feedstock containing free fatty acids and fatty acid glycerides, wherein at least one hydrocarbon chain is unsaturated, to esterification reaction in the presence of an alcohol. An ester stream thereby obtained is then subjected to metathesis conditions in the presence of a renewable alkene to obtain a metathesis product. Separation of the metathesis product includes recovery of a fraction containing or consisting essentially of C16 fatty acid esters, which is subjected to ketonisation reaction conditions to produce long chain ketones, which after hydrotreatment meet requirements for a renewable base oil. Ketonisation reaction produces renewable alkene usable in metathesis reaction.

The present disclosure generally relates to processes to produce alpha-olefin oligomers and poly alpha-olefins. In an embodiment, a process to produce a poly alpha-olefin (PAO) includes introducing a first alpha-olefin and a first catalyst system comprising a metallocene compound into a continuous stirred tank reactor or a continuous tubular reactor under first reactor conditions to form a first reactor effluent. The alpha-olefin is introduced to the reactor at a flow rate of about 100 g/hr or more. The first reactor effluent includes PAO dimer comprising at least 96 mol % of vinylidene and 4 mol % or less of trisubstituted vinylene and disubstituted vinylene, based on total moles of vinylidene, trisubstituted vinylene, and disubstituted vinylene. The method includes introducing the first reactor effluent, a second alpha-olefin and a second catalyst composition comprising an acid catalyst into a second reactor under second reactor conditions to form a second reactor effluent comprising PAO trimer.