A fluorine-containing ether compound represented by Formula (1) is provided.
R.sup.1OR.sup.2CH.sub.2R.sup.3CH.sub.2R.sup.4R.sup.5(1)
(in the formula, R.sup.3 is a perfluoropolyether chain; R.sup.1 is an alkenyl group having 2 to 8 carbon atoms or an alkynyl group having 3 to 8 carbon atoms; R.sup.2 and R.sup.4 are each independently a divalent linking group having one or more hydroxyl groups; and R.sup.5 is a group represented by Formula (2) shown below.)
O(CH.sub.2).sub.gNR.sup.6R.sup.7(2)
(in the formula, g is an integer of 2 or 3; R.sup.6 and R.sup.7 are the same or different saturated aliphatic groups; and R.sup.6 and R.sup.7 may form a ring structure together with a nitrogen atom.)

The present invention provides, among other things, a process to produce a low molecular weight dispersant polymethacrylate polymer (LMWDPMA), and the LMWDPMA itself, along with the use of the LMWDPMA in a lubricating composition, as well as a method for lubricating an internal combustion engine as disclosed herein.

A polyalkylene glycol-based compound may have formula (1): ##STR00001##
wherein R.sup.1 is a monovalent aromatic hydrocarbon group having 6 to 42 ring carbon atoms; R.sup.2 is a monovalent aromatic hydrocarbon group having 6 to 42 carbon atoms or a hydrogen atom; R.sup.3 is a divalent hydrocarbon group having 2 to 4 carbon atoms; and m is a number in a range of from 1 to 40.

The present invention aims to provide a viscosity-index improving agent having an excellent friction reduction effect to reduce friction of a lubricating oil composition 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: (co)polymer (A) containing, as an essential constituent monomer, a polyolefin-based monomer (a) represented by the following formula (1); an ester oil (B1) having a kinematic viscosity at 100 C. of 1.00 to 2.50 mm.sup.2/s; and an ester oil (B2) having a kinematic viscosity at 100 C. of 2.51 to 5.00 mm.sup.2/s: ##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.

The description involves a brush copolymer composition comprising a copolymeric backbone including monomeric repeat units of at least two different acrylate monomers and copolymeric brush arms including monomeric repeat units of at least two different acylated poly(alkylene amine)s, in which the brush arms, the brush copolymer, or both may advantageously exhibit UCST behavior, e.g, in hydrocarbon diluent. Methods of making such copolymers using RAFT and CROP (pseudo-)living reaction processes are also described herein.

A lubricating oil composition may contain a base oil (A) and a dispersant-type viscosity index improver (B), in which the nitrogen atom content based on the solid content of the dispersant-type viscosity index improver (B) is 0.50 to 1.50% by mass, and the weight-average molecular weight (Mw) thereof is 100,000 or more, and the content in terms of the solid content based on the total amount of the composition of the dispersant-type viscosity index improver (B) is more than 0.05% by mass and less than 5.0% by mass. The lubricating oil composition may exert excellent wear resistance in a state contaminated with soot.

A lubricating oil composition, including a base oil (P) and a copolymer (X). The copolymer (X) contains the following structural units (a) to (c): structural unit (a): a structural unit derived from a monomer (A) having a (meth)acryloyl group and a linear or branched alkyl group having 6 to 24 carbon atoms, structural unit (b): a structural unit derived from a monomer (B) having a (meth)acryloyl group and a polar group, and structural unit (c): a structural unit derived from a monomer (C) having a polymerizable functional group and a cyclic structural group. The copolymer (X) has a mass-average molecular weight (Mw) of 5,000 to 50,000, a content of the copolymer (X) in terms of resin content is 0.10% by mass to 2.5% by mass based on the total amount of the lubricating oil composition, and the lubricating oil composition has a 100 C. kinematic viscosity of 8.2 mm.sup.2/s or less.

This disclosure describes low-ash lubricating composition achieving the same or better performance of higher ash compositions by including selected antiwear system with ashless phosphorus-containing antiwear compounds and select detergent systems matching TBN contributions to the antiwear systems.

Provided is a composition for a refrigeration machine capable of reducing a friction coefficient in friction between sliding members in a refrigeration machine, and a composition kit for a refrigeration machine for providing the composition for a refrigeration machine. A composition for a refrigeration machine of the present disclosure includes a refrigeration machine oil, nanodiamond particles dispersed in the refrigeration machine oil, and a dispersant. The refrigeration machine oil preferably contains a polyvinyl ether, a polyol ester, a polyalkylene glycol, an alkylbenzene, or a mineral oil. The composition kit for a refrigeration machine of the present disclosure includes a refrigeration machine oil (A) containing a base oil and nanodiamond particles dispersed in the base oil, and a refrigerant (B).

A composition comprising water and a polyalkylene glycol having an allyl content of less than 20 eq/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.