A comb polymer can be used for reducing a Noack evaporation loss of a lubricant composition, especially of an engine oil composition. Application of the comb polymer to the lubricant composition can bring about the desired reduction. The comb polymer can include specified amounts of macromonomer and alkyl acrylates. Resulting lubricant compositions can include the comb polymer.

A gradient copolymer comprises or consists of n polymer components. The n polymer components each independently represents an addition polymer of a monomer of the formula (I), ##STR00001##
and/or a mixture thereof, or
the n polymer components each independently comprises or consists essential of one or more structural units represented by the formula (I-1), ##STR00002## The symbol n represents an integer within the closed interval [5, ∞]. The average side chain carbon number of the i-th polymer component as determined according to the nuclear magnetic resonance method is expressed as X.sub.i, with the symbol i representing an arbitrary integer from 1 to n, the relationship X.sub.1<X.sub.2< . . . <X.sub.n−1<X.sub.n holds.

Provided herein are lubricant compositions and methods of using the same. These lubricant compositions are useful for providing improved anti-friction and anti-wear properties.

The present disclosure relates to a continuously variable transmission oil composition containing a base oil containing a metallocene polyalpha olefin (mPAO) polymerized with a metallocene catalyst, a viscosity controlling agent containing Polybutadiene hydrogen phosphate Comb Polymethacrylate, and a clean dispersant, and contains mPAO and PHP Comb PMA, which have not been used previously, at a specific ratio to maximize the reduction in low-temperature viscosity while effectively forming an oil film, thereby enhancing fuel efficiency, and at the same time, enhancing durability of a transmission by increasing viscosity.

An electrorheological fluid which comprises a dispersion medium containing fluorine atoms in an amount larger than 0 wt % but not larger than 50.0 wt % and particles for electrorheological fluid use that are contained in the dispersion medium in an amount of 10-50 vol % of the total volume of the dispersion medium and the particles, the particles comprising a sulfonic-acid-group-containing polymer having a sulfonic acid group content of 30-70 wt %.

Disclosed are materials that possess both low adhesion and the ability to absorb water. The material passively absorbs water from the atmosphere and then expels this water upon impact with debris, to create a self-cleaning layer. The lubrication reduces friction and surface adhesion of the debris (such as an insect), which may then slide off the surface. The invention provides a material comprising a continuous matrix including a polymer having a low surface energy (less than 50 mJ/m.sup.2) and a plurality of inclusions, dispersed within the matrix, each comprising a hygroscopic material. The continuous matrix and the inclusions form a lubricating surface layer in the presence of humidity. The material optionally contains porous nanostructures that inject water back onto the surface after an impact, absorbing water under pressure and then releasing water when the pressure is removed. The material may be a coating or a surface, for example.

Disclosed are multifunctional compounds represented by structural formula (I):

##STR00001##

methods of producing compounds represented by structural formula (I) and their use in inhibiting corrosion in corrodible material.

A lubricant composition includes a biodegradable polyalkylene glycol, an inherently-biodegradable polyalkylene glycol, and a non-biodegradable polyalkylene glycol. The biodegradable polyalkylene glycol satisfies the biodegradability requirements set forth in OECD 301B. The inherently-biodegradable polyalkylene glycol satisfy the inherently-biodegradability requirements set forth in OECD 301B. The non-biodegradable polyalkylene glycol is defined by OECD 301B and satisfies the non-bioaccumulative requirements set forth in OECD 107. The lubricant composition includes the biodegradable polyalkylene glycol in an amount of at least about 30 parts by weight, the inherently-biodegradable polyalkylene glycol in an amount of from about 0.1 to about 10 parts by weight, and the non-biodegradable polyalkylene glycol in an amount of from about 0.1 to about 5 parts by weight, each based on 100 parts by weight of the lubricant composition.

A viscosity index improver containing a copolymer (A) whose essential constituent monomer is a monomer (a) having a number average molecular weight of 800 to 4,000 represented by the following formula (1), the copolymer (A) having a solubility parameter in the range of 9.00 to 9.40: ##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—, AO is a C2-C4 alkyleneoxy group, m is an integer of 1 to 10, each AO may be the same or different when m is 2 or more, and the (AO).sub.m moieties may be randomly bonded or block-bonded; R.sup.2 is a residue after removal of one hydrogen atom from a hydrocarbon polymer whose essential constituent monomer is butadiene in which the butadiene is present in a proportion of 50% by weight or more based on the weight of R.sup.2, or after removal of one hydrogen atom from a polymer formed by partial hydrogenation of the hydrocarbon polymer; and p represents a number of 0 or 1.

A viscosity index improver comprising a copolymer having a unit (a) derived from a maleimide monomer and a unit (b) derived from a macromonomer, wherein viscosity measured by the following method is 8000 mPa.Math.s or less. Viscosity measurement method: A solution composed of 78 mass % of a Group III base oil (viscosity index: 122, kinematic viscosity at 40° C.: 19.6 mm.sup.2/s) on the American Petroleum Institute (API) classification and 22 mass % of the copolymer is measured with a viscometer (TVB-10 manufactured by Toki Sangyo Co., Ltd., rotor: SPINDLE No. M3, rotation speed: 6 rpm) at 25° C.