The invention provides a lubricating composition comprising an oil of lubricating viscosity and synergistic mixture of a functionalized ethylene-α-olefin copolymer, a poly(meth)acrylate block polymer having a substantially oil soluble block and a substantially oil insoluble block. The invention also provides a method of lubricating a mechanical device using such a lubricating composition.

The invention provides a lubricating composition comprising an oil of lubricating viscosity and synergistic mixture of a functionalized ethylene-α-olefin copolymer, a poly(meth)acrylate block polymer having a substantially oil soluble block and a substantially oil insoluble block. The invention also provides a method of lubricating a mechanical device using such a lubricating composition.

The present invention aims to provide a viscosity index improver composition and a lubricating oil composition having a low HTHS viscosity at 100° C., an excellent shear stability, and an excellent low temperature viscosity. The present invention relates to, for example, a viscosity index improver composition (C), containing: a copolymer (A) containing a polyolefin-based monomer (a) represented by the following formula (1) as a constituent monomer; a copolymer (B) containing a (meth)acrylic acid alkyl ester (c) having a C12-C15 straight-chain or branched alkyl group and a (meth)acrylic acid alkyl ester (d) having a C16-C20 straight-chain or branched alkyl group as constituent monomers; and a base oil, wherein a weight average molecular weight ratio {(A)/(B)} of the copolymer (A) to the copolymer (B) is 2 to 55, and a weight ratio (A/B) of the copolymer (A) to the copolymer (B) constituting the viscosity index improver composition (C) is 5 to 100: ##STR00001##

The present invention aims to provide a viscosity index improver composition and a lubricating oil composition having a low HTHS viscosity at 100° C., an excellent shear stability, and an excellent low temperature viscosity. The present invention relates to, for example, a viscosity index improver composition (C), containing: a copolymer (A) containing a polyolefin-based monomer (a) represented by the following formula (1) as a constituent monomer; a copolymer (B) containing a (meth)acrylic acid alkyl ester (c) having a C12-C15 straight-chain or branched alkyl group and a (meth)acrylic acid alkyl ester (d) having a C16-C20 straight-chain or branched alkyl group as constituent monomers; and a base oil, wherein a weight average molecular weight ratio {(A)/(B)} of the copolymer (A) to the copolymer (B) is 2 to 55, and a weight ratio (A/B) of the copolymer (A) to the copolymer (B) constituting the viscosity index improver composition (C) is 5 to 100: ##STR00001##

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 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.

Compositions comprising an acrylamide polymer emulsion and a nonionic surfactant suitable for use as friction reducers for hydraulic fracturing are disclosed. The nonionic surfactants include aralkylated phenol ethoxylates, amine ethoxylates, amidoamine ethoxylates, linear or branched alcohol EO/PO alkoxylates, ethoxylated alcohols, alkylphenol ethoxylates, and EO-capped poly(oxypropylene) block copolymers. Improved hydraulic fracturing processes in which an acrylamide polymer emulsion is used as a friction reducer are also described. In these processes, the surfactant is included in the composition with the acrylamide polymer friction reducer, or it is introduced separately into the process. The performance of low-cost polyacrylamide friction reducers can be boosted with a small proportion of certain readily available nonionic surfactants. The inventive compositions are effective in high-salinity environments, and their performance can sometimes exceed that of more-expensive salt-tolerant friction reducers, thereby reducing fresh water demand and enabling greater utilization of produced water.

Compositions comprising an acrylamide polymer emulsion and a nonionic surfactant suitable for use as friction reducers for hydraulic fracturing are disclosed. The nonionic surfactants include aralkylated phenol ethoxylates, amine ethoxylates, amidoamine ethoxylates, linear or branched alcohol EO/PO alkoxylates, ethoxylated alcohols, alkylphenol ethoxylates, and EO-capped poly(oxypropylene) block copolymers. Improved hydraulic fracturing processes in which an acrylamide polymer emulsion is used as a friction reducer are also described. In these processes, the surfactant is included in the composition with the acrylamide polymer friction reducer, or it is introduced separately into the process. The performance of low-cost polyacrylamide friction reducers can be boosted with a small proportion of certain readily available nonionic surfactants. The inventive compositions are effective in high-salinity environments, and their performance can sometimes exceed that of more-expensive salt-tolerant friction reducers, thereby reducing fresh water demand and enabling greater utilization of produced water.

The invention provides a lubricating composition comprising a low viscosity base oil and a synergistic mixture of a functionalized ethylene-α-olefin copolymer, a poly(meth)acrylate polymer, and a metal-free anti-wear agent. The invention also provides a method of lubricating an internal combustion engine using such a lubricating composition.

The invention provides a lubricating composition comprising a low viscosity base oil and a synergistic mixture of a functionalized ethylene-α-olefin copolymer, a poly(meth)acrylate polymer, and a metal-free anti-wear agent. The invention also provides a method of lubricating an internal combustion engine using such a lubricating composition.