A polymer composition, in which a differential distribution value in a differential molecular weight distribution curve of the polymer composition, as measured by gel permeation chromatography, satisfies Equation 1 and a maximum value of a normalized back-scattering intensity of a 35 wt % base oil solution of the polymer composition, where a size q of a scattering vector of small-angle X-ray scattering at 25° C. is in a range of 0.07 nm.sup.−1 or more and 2 nm.sup.−1 or less, is 40 cm.sup.−1 or more.

A hydrocarbon fluid is disclosed that has a pour point of at most −30° C., as measured by ASTM D5950, and that comprises at least 99 wt % of naphthenes and paraffins, based on the total weight of the hydrocarbon fluid, 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, preferred uses of said hydrocarbon fluid are disclosed.

Provided are a lubricant composition for shock absorbers, a lubricant additive, and a method of adjusting friction characteristics of a lubricant composition for shock absorbers, each capable of satisfying both the operational stability and ride comfort. The lubricant composition for shock absorbers contains a base oil and a friction adjusting agent, the friction adjusting agent contains pentaerythritol esters, and the pentaerythritol esters contain a pentaerythritol tetraester and a pentaerythritol ester other than the pentaerythritol tetraester.

Provided are an electroviscous fluid exhibiting a high ER effect and having sufficient durability, and a cylinder device. An electroviscous fluid of the present invention includes a fluid and polyurethane particles containing metal ions. The polyurethane particles have a phase separation structure of a hard segment and a soft segment, and contain an additive increasing a urethane bond forming the hard segment.

A lubricating oil composition which may contain a zinc dialkyl dithiophosphate, and whose color deterioration over time is alleviated. Such a lubricating oil composition may contain: a base oil (A); a zinc dialkyl dithiophosphate (B); and a sodium-based detergent (C). In such a lubricating oil composition, a content of zinc atoms may be 100 ppm by mass to 2,000 ppm by mass based on a total amount of the lubricating oil composition, and a content of sodium atoms may be 5 ppm by mass to 1,000 ppm by mass based on the total amount of the lubricating oil composition.

The present invention provides a water/glycol-based hydraulic fluid that includes a total fatty acid and dimer acid of more than 0.4 and no more than 1.2 mass % as a fatty acid lubricant, and also a phosphate ester at between 0.01 and 0.07 mass %. The phosphate ester has the following structure (1) here R1 and R2 each represent a hydrogen atom or a hydrogen group with a carbon number between 1 and 30, and may either be mutually identical or mutually different; R.sub.3 represents a hydrocarbon group with a carbon number between 1 and 20; R.sub.4 represents a hydrogen atom or a hydrocarbon group with a carbon number between 1 and 30; and X.sub.1, X.sub.2, X.sub.3, and X.sub.4 each indicate an oxygen atom or a sulfur atom, where these may either be mutually identical or mutually different.

##STR00001##

The present invention provides a water-glycol hydraulic fluid comprising 0.3-0.6% by mass in total of fatty acid sodium salt and/or fatty acid, and 0.3-0.6% by mass of dimerized fatty acid. The water-glycol hydraulic fluid also comprises 20-60% by mass water, 20-60% by mass glycol, 0.01-0.06% by mass alkali hydroxide compound selected from potassium hydroxide and/or sodium hydroxide, and 1.0-5.0% by mass alkanolamine.

A lubricating oil composition including a base oil (X) having a tertiary carbon atom at a content of 8.0 at % or more based on the total carbon of hydrocarbons and an antioxidant (Y) having an amine-based antioxidant (A), a phenol-based antioxidant (B), and a phosphor-based antioxidant (C). The amine-based antioxidant (A) includes a diphenylamine compound (A1) represented by the following general formula (a1):

##STR00001##

where R.sup.a1 and R.sup.a2, na1 and na2 are defined in the disclosure.

A lubricating oil composition may be capable of satisfactorily exhibiting sludge prevention properties and wear resistance evaluated by scoring resistance and seizure resistance over a long period of time. Such a lubricating oil composition may contain: a base oil (A); a hindered phenol-based antioxidant (B); one or more imide compounds (C) selected from the group consisting of a monoimide compound (C1) and a bisimide compound (C2); and an extreme pressure agent (D), in which the hindered phenol-based antioxidant (B) is 2,6-di-tert-butylphenol, the monoimide compound (C1) is one or more selected from the group consisting of an alkenyl succinic monoimide compound and an alkyl succinic monoimide compound, and the bisimide compound (C2) is one or more selected from the group consisting of an alkenyl succinic bisimide compound and an alkyl succinic bisimide compound.

Aspects described herein generally relate to methods of making a phosphono paraffin comprising forming a reaction mixture by mixing a haloparaffin, a phosphite, and sodium iodide. Methods comprise heating the reaction mixture to form the phosphono paraffin. Aspects described herein further relate to a phosphono paraffin represented by formula (I): ##STR00001##
wherein each instance of R.sup.1 is independently ##STR00002##
wherein each instance of R.sup.2 and R.sup.3 is independently linear or branched C.sub.1-20 alkyl, C.sub.1-20 cycloalkyl, or aryl; the number of instances where R.sup.1 is ##STR00003##
of formula (I) is between about 2 and about 8; and n is an integer between 4 and 22.