Lubricating oil composition containing viscosity modifier with low shear stability index

Abstract

A method of improving fuel economy of an engine is described. The method comprises lubricating the engine with a lubricating oil composition comprising a) an oil of lubricating viscosity; and b) a viscosity modifier comprising an olefin copolymer or a diene-based copolymer or homopolymer, wherein the viscosity modifier has a shear stability index of 15 or less. The lubricating oil composition is substantially free of viscosity modifiers other than the viscosity modifier of b).

Description

Technical Field

[0001] The present disclosure relates to a method of improving fuel economy by formulating a low SSI viscosity improver in a lubricating oil composition. Background Art

[0002] Improving fuel economy is an important driver for the development of advanced lubricant technology. Generally speaking, lubricants with lower viscosity at a given temperature and shear conditions provide better fuel economy due to reduced viscous drag. Viscosity modifiers or viscosity index improvers, particularly those with improved shear stability, can modify the rheological properties of engine oils to help achieve better fuel economy in vehicles. Summary of the invention

[0003] The present disclosure relates to a method for improving the fuel economy of an engine, the method comprising: lubricating the engine with a lubricating oil composition, the lubricating oil composition comprising: a) an oil of lubricating viscosity; and b) a viscosity improver comprising an olefin copolymer or a diene-based copolymer or homopolymer, wherein the viscosity improver has a shear stability index of 15 or less; wherein the lubricating oil composition is substantially free of a viscosity improver other than the viscosity improver of b).

[0004] In another aspect, the present disclosure is directed to a method for improving fuel economy of a diesel engine, the method comprising: lubricating the diesel engine with a lubricating oil composition, the lubricating oil composition comprising: a) an oil of lubricating viscosity; and b) a viscosity improver comprising an olefin copolymer or a diene-based copolymer or homopolymer, wherein the viscosity improver has a shear stability index of 15 or less; wherein the lubricating oil composition is substantially free of a viscosity improver other than the viscosity improver of b). DETAILED DESCRIPTION

[0005] As used herein, a "polymer" has two or more monomeric units that are the same or different. A "homopolymer" is a polymer having the same monomeric units. A "copolymer" is a polymer having two or more monomeric units that are different from each other.

[0006] As used herein, the term "substituted" means that a hydrogen has been replaced by a heteroatom or a heteroatom-containing group. For example, a "substituted hydrocarbyl" is a group consisting of carbon and hydrogen in which at least one hydrogen is replaced by a heteroatom or a heteroatom-containing group.

[0007] As used herein, Mn is the number average molecular weight, Mw is the weight average molecular weight, Mz is the z average molecular weight, wt.% is the weight percent, and mol% is the mole percent. Molecular weight distribution (MWD), also known as polydispersity (PDI), is defined as Mw divided by Mn. Unless otherwise indicated, all molecular weight units (e.g., Mw, Mn, Mz) are g / mol.

[0008] The Shear Stability Index (SSI) refers to the resistance of a polymer to mechanical degradation (polymer curl breakage) under shear stress as measured by ASTM D6278 and D7109. For example, an SSI of 50 means that the polymer will lose 50% of the viscosity it contributes to the lubricant before degradation.

[0009] At least one previous study has shown that polymers with higher SSI are used to improve fuel economy at a constant HTHS150 (high temperature high shear viscosity at 150°C) or KV100 (kinematic viscosity at 100°C). U.S. Publication No. 20130143782 claims that an increase in the ratio of high / low SSI polymers provides fuel economy enhancement. This is expected given that the shear thinning contribution increases with increasing SSI polymer content.

[0010] In the present disclosure, it is unexpectedly discovered that a lubricating oil composition comprising a low SSI viscosity improver can improve the fuel economy of an internal combustion engine. This improvement can be verified or determined by measuring the increase in fuel economy (referred to as "fuel economy improvement") from a standardized dynamometer test (such as the World Uniform Transient Cycle or the Heavy Duty Supplemental Emissions Test).

[0011] The present disclosure relates to low SSI viscosity improvers (or viscosity index improvers) in lubricating oil compositions and / or methods of using the same. As used herein, the term "low SSI" or "low shear stability index" means 15 or less, such as 14 or less, 13 or less, 12 or less, 11 or less, 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, 3 or less, 2 or less, 1 or less, 1 to 15, 1 to 14, 1 to 13, 1 to 12, 1 to 11, 1 to 10, 1 to 9, 1 to 8, 1 to 7, 1 to 6, 1 to 5, 1 to 4, 1 to 3, 1 to 2, 2 to 15, 2 to 14, 2 to 13, 2 to 12, 2 to 11, 2 to 10, 2 to 9, 2 to 8, 2 to 7, 2 to 6, 2 to 5, 2 to 4, 2 to 3, 3 to 15, 3 to 14, 3 to 13, 3 to 12, 3 to 11, 3 to 10, 3 to 9, 3 to 8, 3 to 7, 3 to 6, 3 to 5, 3 to 4, 4 to 15, 4 to 14, 4 to 13, 4 to 12, 4 to 11, 4 to 10, 4 to 9, 4 to 8, 4 to 7, 4 to 6, 4 to 5, 5 to 15, 5 to 14, 5 to 13, 5 to 12, 5 to 11, 5 to 10, 5 to 9, 5 to 8, 5 to 7, 5 to 6, 6 to 15, 6 to 14, 6 to 13, 6 to 12, 6 to 11, 6 to 10, 6 to 9, 6 to 8, 6 to 7, 7 to 15, 7 to 14, 7 to 13, 7 to 12, 7 to 11, 7 to 10, 7 to 9, 7 to 8, 8 to 15 , 8 to 14, 8 to 13, 8 to 12, 8 to 11, 8 to 10, 8 to 9, 9 to 15, 9 to 14, 9 to 13, 9 to 12, 9 to 11, 9 to 10, 10 to 15, 10 to 14, 10 to 13, 10 to 12, 10 to 11, 11 to 15, 11 to 14, 11 to 13, 11 to 12, 12 to 15, 12 to 14, 12 to 13, 13 to 15, 13 to 14, or 14 to 15.

[0012] According to one embodiment, a method for improving fuel economy includes:

[0013] An internal combustion engine is lubricated with a lubricating oil composition, the lubricating oil composition comprising:

[0014] a) a major amount of oil of lubricating viscosity; and

[0015] b) a viscosity improver comprising an olefin copolymer or a diene-based copolymer or homopolymer (e.g., a hydrogenated diene-based polymer), wherein the viscosity improver has an SSI of 15 or less. Generally, the lubricating oil composition does not contain a viscosity improver other than the viscosity improver of b). In some embodiments, the lubricating oil composition contains less than 0.01 wt.% of other viscosity improvers. Other viscosity improvers include polyalkyl methacrylate (PMA) polymers and the like.

[0016] Viscosity Improver

[0017] The viscosity improver of the present disclosure is a low SSI polymer, wherein the viscosity improver is i) an ethylene-propylene based olefin copolymer or ii) a diene based copolymer or homopolymer.

[0018] For the purpose of this specification and the appended claims, when a polymer is referred to as comprising an olefin, the olefin present in such a polymer is a polymerized form of an olefin. For example, an olefin copolymer based on ethylene-propylene is a polymer consisting of olefin monomers (i.e., ethylene and propylene). In some embodiments, an olefin polymer ("polyolefin" or "polyolefin polymer"), such as a poly-alpha-olefin polymer made from propylene or other C3 or higher alpha-olefin monomers, may include a hydrocarbyl group pendant from the polymer backbone.

[0019] In some embodiments, the shape of the viscosity modifiers of the present disclosure may be linear. In some embodiments, the viscosity modifiers compatible with the present disclosure may be star-shaped. In some embodiments, the viscosity modifiers compatible with the present disclosure may be random copolymers in which the monomer residues are randomly positioned.

[0020] The term "linear" means that the viscosity improver has little, if any, long chain branching and has a g'vis value of about 0.97 or higher, such as about 0.98 or higher.

[0021] "Star" means that the viscosity improver has a multifunctional center (e.g., a polyolefin coupling agent core) from which at least three polymer arms radiate. In some embodiments, each polymer arm can be chemically identical (homostar). In some embodiments, each polymer arm is chemically different (heterostar). In some embodiments, the polymer arms include linear copolymers or homopolymers. Star polymers can be hydrogenated to form hydrogenated star polymers. A more detailed discussion of star polymers can be found in U.S. Pat. Nos. 4,116,917 and 4,141,847, which are hereby incorporated by reference.

[0022] 1. Ethylene-propylene based olefin copolymers

[0023] According to one embodiment, the olefin copolymer is an ethylene-propylene based olefin copolymer (OCP). Ethylene-propylene based OCPs are typically produced by the polymerization of ethylene and propylene monomers.

[0024] The ethylene-propylene based olefin copolymer has a molecular weight of about 10,000 g / mol to 100,000 g / mol, such as about 20,000 g / mol to 100,000 g / mol, 20,000 g / mol to 90,000 g / mol, 20,000 g / mol to 80,000 g / mol, 20,000 g / mol to 70,000 g / mol, 20,000 g / mol to 60,000 g / mol, 20,000 g / mol to 50,000 g / mol, 20,000 g / mol to 40,000 g / mol, 20,000 g / mol to 30,000 g / mol. g / mol, 30,000 g / mol to 100,000 g / mol, 30,000 g / mol to 90,000 g / mol, 30,000 g / mol to 80,000 g / mol, 30,000 g / mol to 70,000 g / mol, 30,000 g / mol to 60,000 g / mol, 30,000 g / mol to 50,000 g / mol, 30,000 g / mol to 40,000 g / mol, 40,000 g / mol to 100,000 g / mol, 40,000 g / mol to 9 ... g / mol to 80,000 g / mol, 40,000 g / mol to 70,000 g / mol, 40,000 g / mol to 60,000 g / mol, 40,000 g / mol to 50,000 g / mol, 50,000 g / mol to 100,000 g / mol, 50,000 g / mol to 90,000 g / mol, 50,000 g / mol to 80,000 g / mol, 50,000 g / mol to 70,000 g / mol, 50,000 g / mol to 60,000 g / mol, 60,000 g / mol to 100,000 g / mol The present invention relates to an aqueous solution of at least one molecule of the present invention and to a weight average molecular weight (Mw) in the range of 50,000 g / mol to 90,000 g / mol, 50,000 g / mol to 80,000 g / mol, 50,000 g / mol to 70,000 g / mol, 50,000 g / mol to 100,000 g / mol, 50,000 g / mol to 90,000 g / mol, 50,000 g / mol to 80,000 g / mol, 50,000 g / mol to 100,000 g / mol, 50,000 g / mol to 90,000 g / mol,

[0025] In some preferred embodiments, the ethylene-propylene based olefin copolymer has a molecular weight of about 30,000 g / mol to 80,000 g / mol, such as 30,000 g / mol to 75,000 g / mol, 30,000 g / mol to 65,000 g / mol, 30,000 g / mol to 55,000 g / mol, 30,000 g / mol to 45,000 g / mol, 30,000 g / mol to 35,000 g / mol, 35,000 g / mol to 80,000 g / mol, 35,000 g / mol to 75,000 g / mol, 35,000 g / mol to 65,000 g / mol, 35,000 g / mol to 55,000 g / mol, 35,000 g / mol to 45,000 g / mol In some embodiments, the present invention relates to an aqueous phase having a weight average molecular weight (Mw) in the range of 4000 g / mol to 55,000 g / mol, 45,000 g / mol to 80,000 g / mol, 45,000 g / mol to 75,000 g / mol, 45,000 g / mol to 65,000 g / mol, 45,000 g / mol to 55,000 g / mol, 55,000 g / mol to 80,000 g / mol, 55,000 g / mol to 75,000 g / mol, 55,000 g / mol to 65,000 g / mol, 65,000 g / mol to 80,000 g / mol, 65,000 g / mol to 75,000 g / mol, or 75,000 g / mol to 80,000 g / mol.

[0026] In one embodiment, the ethylene-propylene copolymer is ethylene-based. According to one embodiment, the ethylene-propylene copolymer based on ethylene has about 35wt.% to about 70wt.%, based on the total weight of the ethylene-based olefin copolymer, such as about 35wt.% to about 65wt.%, about 35wt.% to about 60wt.%, about 35wt.% to about 55wt.%, about 35wt.% to about 50wt.%, about 35wt.% to about 45wt.%, about 35wt.% to about 40wt.%, about 40wt.% to about 70wt.%, about 40wt.% to about 65wt.%, about 40wt.% to about 60wt.%, about 40wt.% to about 55wt.%, about 40wt.% to about 50wt.%, about 40wt.% to about 45wt.%, about 35wt.% to about 40wt.%, about 40wt.% to about 70wt.%, about 40wt.% to about 65wt.%, about 40wt.% to about 60wt.%, about 40wt.% to about 55wt.%, about 40wt.% to about 50wt.%, about 40wt.% to about 45wt.%, % to about 70 wt.%, about 45 wt.% to about 65 wt.%, about 45 wt.% to about 60 wt.%, about 45 wt.% to about 55 wt.%, about 45 wt.% to about 50 wt.%, about 50 wt.% to about 70 wt.%, about 50 wt.% to about 65 wt.%, about 50 wt.% to about 60 wt.%, about 50 wt.% to about 55 wt.%, about 55 wt.% to about 70 wt.%, about 55 wt.% to about 65 wt.%, about 55 wt.% to about 60 wt.%, about 60 wt.% to about 70 wt.%, about 60 wt.% to about 65 wt.%, or about 65 wt.% to about 70 wt.% total ethylene content. When a copolymer is referred to as having an "ethylene" content of 35 to 70 wt.%, it is understood that the monomer units in the copolymer are derived from ethylene in the polymerization reaction, and that the derived units are present at 35 to 70 wt.%, based on the weight of the copolymer.

[0027] In another embodiment, the ethylene-propylene based copolymer is propylene based. According to another embodiment, the ethylene-propylene based copolymer has about 1 wt.% to about 20 wt.%, based on the total weight of the ethylene-based olefin copolymer, such as about 1 wt.% to 19 wt.%, about 1 wt.% to about 18 wt.%, about 1 wt.% to about 17 wt.%, about 1 wt.% to about 16 wt.%, about 1 wt.% to about 15 wt.%, about 1 wt.% to about 14 wt.%, about 1 wt.% to about 13 wt.%, about 1 wt.% to about 12 wt.%, about 1 wt.% to about 11 wt.%, about 1 wt.% to about 10 wt.%, about 1 wt.% to about 9 wt.%, about 1 wt.% to about 8 wt.%, about 1 wt.% to about %, about 1 wt.% to about 15 wt.%, about 1 wt.% to about 16 wt.%, about 2 wt.% to about 17 wt.%, about 2 wt.% to about 18 wt.%, about 2 wt.% to about 19 wt.%, about 2 wt.% to about 19 wt.%, about 2 wt.% to about 18 wt.%, about 2 wt.% to about 19 wt.%, about 2 wt.% to about 19 wt.%, about 2 wt.% to about 19 wt.%, about 2 wt.% to about 19 wt.%, about 2 wt.% to about 19 wt.%, about 2 wt.% to about 19 wt.%, about 2 wt.% to about 11 wt.%, about 2 wt.% to about 12 wt.%, about 2 wt.% to about 13 wt.%, about 2 wt.% to about 14 wt.%, about 2 wt.% to about 15 wt.%, about 2 wt.% to about 16 wt.%, about 2 wt.% to about 17 wt.%, about 2 wt.% to about 18 wt.%, about 2 wt.% to about 19 wt.%, about % to about 8wt.%, about 2wt.% to about 7wt.%, about 2wt.% to about 6wt.%, about 2wt.% to about 5wt.%, about 2wt.% to about 4wt.%, about 2wt.% to about 3wt.%, about 3wt.% to about 20wt.%, about 3wt.% to about 19wt.%, about 3wt.% to about 18wt.%, about 3wt.% to about 17wt.%, about 3wt.% to about 16wt.%, about 3wt.% to about 15wt.%, about 3wt.% to about 14wt.%, about 3wt.% to about 13wt.%, about 3wt.% to about 12wt.%, about 3wt.% to about 11wt.%, about 3wt.% to about 10wt. %, about 3 wt.% to about 10 wt.%, about 3 wt.% to about 9 wt.%, about 3 wt.% to about 8 wt.%, about 3 wt.% to about 7 wt.%, about 3 wt.% to about 6 wt.%, about 3 wt.% to about 5 wt.%, about 3 wt.% to about 4 wt.%, about 4 wt.% to about 20 wt.%, about 4 wt.% to about 19 wt.%, about 4 wt.% to about 18 wt.%, about 4 wt.% to about 17 wt.%, about 4 wt.% to about 16 wt.%, about 4 wt.% to about 15 wt.%, about 4 wt.% to about 14 wt.%, about 4 wt.% to about 13 wt.%, about 4 wt.% to about 12 wt.%, about 4 wt.%, about 5 wt.% to about 15 wt.%, about 5 wt.% to about 16 wt.%, about 5 wt.% to about 17 wt.%, about 5 wt.% to about 18 wt.%, about 5 wt.% to about 19 wt.%, about 5 wt.% to about 20 wt.%, about 5 wt.% to about 21 wt.%, about 5 wt.% to about 22 wt.%, about 5 wt.% to about 24 wt.%, about 5 wt.% to about 26 wt.%, about 5 wt.% to about 27 wt.%, about 5 wt.% to about 28 wt.%, about 5 wt.% to about 29 wt.%, about 6 wt.% to about 30 wt.%, about 6 wt.% to about 31 wt.%, about 6 wt.% to about 32 wt.%, about 6 wt.% to about 33 wt.%, about 6 wt.% to about 34 wt.%, about 6 wt.% to about 35 wt.%, about 6 wt.% to about 36 wt.%, about 6 wt.% to about 37 wt.%, about 6 wt.% to about 38 wt.%, about 6 wt.% to about 39 wt. % to about 10 wt.%, about 5 wt.% to about 9 wt.%, about 5 wt.% to about 8 wt.%, about 5 wt.% to about 7 wt.%, about 5 wt.% to about 6 wt.%, about 6 wt.% to about 20 wt.%, about 6 wt.% to about 19 wt.%, about 6 wt.% to about 18 wt.%, about 6 wt.% to about 17 wt.%, about 6 wt.% to about 16 wt.%, about 6 wt.% to about 15 wt.%, about 6 wt.% to about 14 wt.%, about 6 wt.% to about 13 wt.%, about 6 wt.% to about 12 wt.%, about 6 wt.% to about 11 wt.%, about 6 wt.% to about 10 wt.%, about 6 wt.% to about 10 wt.%, about %, about 7 wt.% to about 15 wt.%, about 7 wt.% to about 16 wt.%, about 7 wt.% to about 17 wt.%, about 7 wt.% to about 18 wt.%, about 7 wt.% to about 19 wt.%, about 7 wt.% to about 19 wt.%, about 7 wt.% to about 18 wt.%, about 7 wt.% to about 17 wt.%, about 7 wt.% to about 16 wt.%, about 7 wt.% to about 16 wt.%, about 7 wt.% to about 15 wt.%, about 7 wt.% to about 14 wt.%, about 7 wt.% to about 13 wt.%, about 7 wt.% to 12 wt.%, about 7 wt.% to about 11 wt.%, about 7 wt.% to about 10 wt.%, about 7 wt.% to about 9 wt.%, about 7 wt.% to about 8 wt.%, about 8 wt.% to about 20wt.%, about 8wt.% to about 19wt.%, about 8wt.% to about 18wt.%, about 8wt.% to about 17wt.%, about 8wt.% to about 16wt.%, about 8wt.% to about 15wt.%, about 8wt.% to about 14wt.%, about 8wt.% to about 13wt.%, about 8wt.% to about 12wt.%, about 8wt.% to about 12wt.%, about 8wt.% to about 11wt.%, about 8wt.% to about 10wt.%, about 8wt.% to about 9wt.%, about 9wt.% to about 20wt.%, about 9wt.% to about 19wt.%, about 9wt.% to about 18wt.%, about 9wt.% to about 17wt.%, about 9 wt.% to about 16 wt.%, about 9 wt.% to about 15 wt.%, about 9 wt.% to about 14 wt.%, about 9 wt.% to about 13 wt.%, about 9 wt.% to about 12 wt.%, about 9 wt.% to about 11 wt.%, about 9 wt.% to about 10 wt.%, about 10 wt.% to about 20 wt.%, about 10 wt.% to about 19 wt.%, about 10 wt.% to about 18 wt.%, about 10 wt.% to about 17 wt.%, about 10 wt.% to about 16 wt.%, about 10 wt.% to about 16 wt.%, about 10 wt.% to about 15 wt.%, about 10 wt.% to about 14 wt.%, about 10 wt.% to about 13 wt.% %, about 10 wt.% to about 12 wt.%, about 10 wt.% to about 11 wt.%, about 11 wt.% to about 20 wt.%, about 11 wt.% to about 19 wt.%, about 11 wt.% to about 18 wt.%, about 11 wt.% to about 17 wt.%, about 11 wt.% to about 16 wt.%, about 11 wt.% to about 15 wt.%, about 11 wt.% to about 14 wt.%, about 11 wt.% to about 13 wt.%, about 11 wt.% to about 12 wt.%, about 12 wt.% to about 20 wt.%, about 12 wt.% to about 19 wt.%, about 12 wt.% to about 18 wt.%, about 12 wt.% to about 17 wt.%, about 12 wt.% to about %, about 12 wt.% to about 15 wt.%, about 12 wt.% to about 14 wt.%, about 12 wt.% to about 13 wt.%, about 13 wt.% to about 20 wt.%, about 13 wt.% to about 19 wt.%, about 13 wt.% to about 18 wt.%, about 13 wt.% to about 17 wt.%, about 13 wt.% to about 16 wt.%, about 13 wt.% to about 15 wt.%, about 13 wt.% to about 14 wt.%, about 14 wt.% to about 20 wt.%, about 14 wt.% to about 19 wt.%, about 14 wt.% to about 18 wt.%, about 14 wt.% to about 17 wt.%, about 14 wt.% to about 16 wt.%, about 14 % to about 15wt.%, about 15wt.% to about 20wt.%, about 15wt.% to about 19wt.%, about 15wt.% to about 18wt.%, about 15wt.% to about 17wt.%, about 15wt.% to about 16wt.%, about 16wt.% to about 20wt.%, about 16wt.% to about 19wt.%, about 16wt.% to about 18wt.%, about 16wt.% to about 18wt.%, about 16wt.% to about 17wt.%, about 17wt.% to about 20wt.%, about 17wt.% to about 19wt.%, about 17wt.% to about 18wt.%, about 18wt.% to about 20wt.%, about 18wt.% to about 19wt.% or about 19 wt.% to about 20 wt.% total ethylene content.

[0028] In some preferred embodiments, the propylene-based ethylene-propylene copolymer has an ethylene content in the range of 4 to 10 wt.%. In some preferred embodiments, the propylene-based ethylene-propylene copolymer has an ethylene content in the range of 6.5 to 8.5 wt.%.

[0029] The ethylene-propylene based olefin copolymers can be prepared by any compatible polymerization process. For example, the polymerization can be carried out in homogeneous, bulk, solution (including supercritical) phase, slurry phase and gas phase type reactions.

[0030] Solution polymerization means a polymerization method in which a monomer is dissolved in a liquid polymerization medium (such as an inert solvent or monomer or a blend thereof). Solution polymerization can be homogeneous. Homogeneous polymerization is a polymerization in which the polymer product is dissolved in a polymerization medium. Such systems are not as turbid as described in J. Vladimir Oliveira, C. Dariva and JCPinto, Ind. Eng. Chem. Res., 2000, Vol. 29, p. 4627. Bulk polymerization means a polymerization method in which the monomers and / or comonomers polymerized are used as solvents or diluents, using little or no inert solvents as solvents or diluents. A small portion of an inert solvent can be used as a carrier for a catalyst and a scavenger. The bulk polymerization system contains less than about 25 wt.%, such as less than about 10 wt.%, such as less than about 1 wt.%, such as about 0 wt.% of an inert solvent or diluent.

[0031] In some embodiments, the polymerization process can be run in batch, semi-batch, or continuous mode.In addition, the polymerization process can be carried out in a system having a single reactor or multiple reactors (in series and / or parallel configuration).

[0032] Suitable diluents / solvents for polymerization include non-coordinating inert liquids. Examples include straight chain and branched hydrocarbons such as isobutane, butane, pentane, isopentane, hexane, isohexane, heptane, octane, dodecane and mixtures thereof; cyclic and alicyclic hydrocarbons such as cyclohexane, cycloheptane, methylcyclohexane, methylcycloheptane and mixtures thereof such as those found on the market (Isopar TM); perhalogenated hydrocarbons, such as perfluorinated C4-C10 alkanes, chlorobenzene, and aromatic and alkyl-substituted aromatic compounds, such as benzene, toluene, mesitylene, and xylene. Suitable solvents also include liquid olefins that can act as monomers or comonomers, including ethylene, propylene, 1-butene, 1-hexene, 1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-octene, 1-decene, and mixtures thereof. In at least one embodiment, aliphatic hydrocarbon solvents are used as solvents, such as isobutane, butane, pentane, isopentane, hexane, isohexane, heptane, octane, dodecane, and mixtures thereof; cyclic and alicyclic hydrocarbons, such as cyclohexane, cycloheptane, methylcyclohexane, methylcycloheptane, and mixtures thereof. In at least one embodiment, the solvent is not aromatic, such as aromatic compounds are present in the solvent at less than about 1 wt%, such as less than about 0.5 wt%, such as less than about 0 wt%, based on the weight of the solvent.

[0033] Suitable polymerization can be run at any temperature and / or pressure suitable for obtaining the desired polymer. In at least one embodiment, the temperature and / or pressure include a temperature in the range of about 0°C to about 300°C, such as about 30°C to about 200°C, such as about 60°C to about 195°C, such as about 75°C to about 190°C, such as about 80°C to about 100°C; and a pressure in the range of about 0.35MPa to about 1500MPa, such as about 0.45MPa to about 100MPa, such as about 0.5MPa to about 50MPa, such as about 1.7MPa to about 30MPa. In at least one embodiment, the suitable operating time of the polymerization reaction is up to about 300 minutes, such as in the range of about 0 to about 250 minutes, such as about 0 to about 120 minutes, such as about 0 to about 30 minutes, such as about 0 to about 10 minutes.

[0034] In some embodiments, the olefin copolymers of the present disclosure are obtained by visbreaking to controllably reduce the molecular weight. Visbreaking generally involves an extruder and may involve a visbreaking agent. The process is described in, for example, U.S. Patent Publication No. 2021024789 and U.S. Patent Nos. 3,697,429; 5,391,617; 6,753,381; 5,837,773; 5,068,047, which are hereby incorporated by reference.

[0035] Other monomers

[0036] In some embodiments, the polymerization of olefin copolymers based on ethylene-propylene may include at least one additional monomer. Suitable examples of at least one additional monomer include substituted or unsubstituted C2 to C40 alpha olefins, such as C2 to C20, C2 to C15, C2 to C10, C5 to C40, C5 to C20, C5 to C10, C10 to C40, C10 to C20 or C10 to C15 alpha olefins. C2 to C40 olefin monomers can be linear, branched or cyclic. C2 to C40 cyclic olefins can be strained or unstrained, monocyclic or polycyclic, and can optionally include heteroatoms and / or one or more functional groups.

[0037] Specific examples of additional monomers include butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, norbornene, norbornadiene, dicyclopentadiene, cyclopentene, cycloheptene, cyclooctene, cyclooctadiene (e.g., 1,5-cyclooctadiene), cyclododecene, 7-oxa-norbornene, 7-oxa-norbornadiene, substituted derivatives thereof, and isomers thereof. Derivatives include, for example, 1-hydroxy-4-cyclooctene, 1-acetoxy-4-cyclooctene, 5-methylcyclopentene, and dicyclopentadiene.

[0038] 2. Diene-based copolymers / homopolymers

[0039] In some embodiments, the viscosity modifier is a homopolymer or copolymer based on a diene. The copolymer may be derived from the polymerization of two or more conjugated diene monomers. The homopolymer may be derived from the polymerization of a single conjugated diene monomer. In some embodiments, the diene-based copolymer or homopolymer is at least partially or completely hydrogenated.

[0040] Conjugated diene monomers contain at least two double bonds that are conjugated to each other, such as positioned in a 1,3 relationship. Conjugated diene monomers compatible with the present disclosure include conjugated dienes containing 4 to 20 carbon atoms, such as, for example, 1,3-butadiene, isoprene, piperylene, 4-methylpenta-1,3-diene, 2-phenyl-1,3-butadiene, 3,4-dimethyl-1,3-hexadiene and 4,5-diethyl-1,3-octadiene. In some embodiments, conjugated diene monomers can be incorporated in more than one configuration. For example, isoprene monomers can be incorporated in the form of 1,4- or 3,4-units or mixtures thereof. In some embodiments, most of the isoprene is incorporated into the polymer in the form of 1,4-units, such as greater than about 60% by mass, more preferably greater than about 80% by mass, such as about 80 to 100% by mass, and most preferably greater than about 90% by mass, such as about 93% by mass to 100% by mass.

[0041] Similarly, butadiene monomers may be incorporated in the form of 1,2- or 1,4-units. In some embodiments, a majority of the butadiene is incorporated into the polymer in the form of 1,4 units, such as at least about 70% by mass, such as at least about 75% by mass, at least about 80% by mass, at least about 85% by mass, at least about 90% by mass, such as 95 to 100% by mass.

[0042] Linear diblock copolymer (styrene hydrogenated diene)

[0043] In some embodiments, the viscosity modifier is a linear polymer, such as a linear diblock copolymer.

[0044] The non-limiting example of a linear diblock copolymer is a polymer comprising a block derived primarily from a vinyl aromatic hydrocarbon monomer and another block derived primarily from one or more conjugated diene monomers. An example is styrene hydrogenated diene (sometimes referred to as "hydrogenated styrene diene"). Useful vinyl aromatic hydrocarbon monomers include those containing 8 to 16 carbon atoms, such as, for example, styrene, alkyl substituted styrene, alkoxy substituted styrene, vinyl naphthalene and alkyl substituted vinyl naphthalene. The amount of the vinyl aromatic content of the copolymer can be between 5% and 40% by mass of the copolymer.

[0045] A diblock copolymer typically has two distinct blocks, where each block is different from the adjacent block. For example, a diblock copolymer may comprise two homopolymer subunits connected by one or more covalent bonds. In some cases, a diblock copolymer may require non-repeating subunits.

[0046] The diblock structure is particularly consistent with the following general formula: – (A) x -(B) y -, wherein x and y are integers such that the diblock polymer has a molecular weight consistent with the disclosure herein. Non-limiting examples of diblock structures include the following: -AABB- or -AAB- or -ABB-, wherein A and B represent repeating units.

[0047] Linear copolymers compatible with the present disclosure may have a molecular weight between 40,000 g / mol and 150,000 g / mol, such as 40,000 g / mol to 125,000 g / mol, 40,000 g / mol to 100,000 g / mol, 40,000 g / mol to 75,000 g / mol, 40,000 g / mol to 50,000 g / mol, 50,000 g / mol to 150,000 g / mol, 50,000 g / mol to 125,000 g / mol, 50,000 g / mol to 75,000 g / mol, 1 to 100,000 g / mol, 50,000 g / mol to 75,000 g / mol, 75,000 g / mol to 150,000 g / mol, 75,000 g / mol to 1250,000 g / mol, 75,000 g / mol to 100,000 g / mol, 100,000 g / mol to 150,000 g / mol, 100,000 g / mol to 125,000 g / mol, or 125,000 g / mol to 150,000 g / mol. As used herein, the term "weight average molecular weight" refers to the weight average weight after hydrogenation as measured by gel permeation chromatography ("GPC") with polystyrene standards.

[0048] In some preferred embodiments, the linear copolymer may have a molecular weight of 40,000 g / mol to 80,000 g / mol, such as 40,000 to 75,000, 40,000 to 65,000 g / mol, 40,000 to 55,000 g / mol, 40,000 to 45,000 g / mol, 45,000 to 80,000 g / mol, 45,000 to 75,000 g / mol, 1, 45,000 g / mol to 65,000 g / mol, 45,000 g / mol to 55,000 g / mol, 55,000 g / mol to 80,000 g / mol, 55,000 g / mol to 75,000 g / mol, 55,000 g / mol to 65,000 g / mol, 65,000 g / mol to 80,000 g / mol, or 65,000 g / mol to 75,000 g / mol.

[0049] Useful block copolymers include those prepared in bulk, suspension, solution or emulsion.Polymerization can be accomplished using free radical, cationic and anionic initiators or polymerization catalysts such as transition metal catalysts for Ziegler-Nata and metallocene-type (also known as "single site") catalysts.

[0050] Non-limiting examples of linear diblock copolymers include copolymers comprising polystyrene blocks and blocks derived from conjugated diene monomers such as isoprene, butadiene, or mixtures thereof. In some embodiments, the linear diblock copolymers may be at least partially hydrogenated.

[0051] In some embodiments, the block derived from the vinyl aromatic hydrocarbon monomer (e.g., styrene) in the linear diblock copolymer may be present in an amount of up to 35 mass %, such as up to 25 mass %, such as 5 mass % to 25 mass %, based on the total mass of the linear diblock copolymer. In some embodiments, the block derived from the conjugated diene monomer is present in an amount greater than 65 mass %, even more preferably greater than or equal to 75 mass %, and most preferably 75 mass % to 95 mass %, based on the total mass of the linear diblock copolymer.

[0052] Examples of commercially available styrene / hydrogenated diene linear diblock copolymers include Infineum SV140 available from Infineum USA LP and Infineum UK Ltd. TM 、Infineum SV150 TM and Infineum SV160 TM ; Available from The Lubrizol Corporation 7408A; and Septon 1001 available from Kuraray Company of America (Kuraray Group) TM and Septon 1020 TM Suitable styrene / 1,3-butadiene hydrogenated block copolymers are available from BASF under the trade name Glissoviscal TM sell.

[0053] Star polymer

[0054] In some embodiments, the viscosity modifiers of the present disclosure are star-shaped, wherein the star polymer is at least partially hydrogenated. In some embodiments, the star polymer comprises or is at least partially derived from the polymerization of one or more conjugated diene monomers. The star polymer includes a plurality of arms extending from a central core. In some embodiments, the polymer arms include a diene-based copolymer or homopolymer.

[0055] The arms of the star polymer may be homopolymers derived from the polymerization of a single conjugated diene monomer such as isoprene or 1,3-butadiene.

[0056] Alternatively, the arms of the star polymer can be copolymers derived from the polymerization of two or more conjugated diene monomers, such as isoprene and 1,3-butadiene copolymers, or copolymers derived substantially from the polymerization of one or more conjugated diene monomers and vinyl aromatic hydrocarbon monomers, such as isoprene-styrene copolymers, butadiene-styrene copolymers, or isoprene-butadiene-styrene copolymers.

[0057] The arms of the star polymer can be formed by anionic polymerization to form a living polymer. Anionic polymerization has been found to provide polymers having a narrow molecular weight distribution (Mw / Mn), such as a molecular weight distribution of less than about 1.2.

[0058] The star polymers useful in the practice of the present invention may have a molecular weight of about 300,000 g / mol to 1,000,000 g / mol, such as 300,000 g / mol to 900,000 g / mol, 300,000 g / mol to 800,000 g / mol, 300,000 g / mol to 700,000 g / mol, 300,000 g / mol to 600,000 g / mol, 300,000 g / mol to 500,000 g / mol, 300,000 g / mol to 500,000 g / mol, 300,000 g / mol to 600,000 g / mol, 300,000 g / mol to 700,000 g / mol, 300,000 g / mol to 800,000 g / mol, 300,000 g / mol to 900,000 g / mol, 300,000 g / mol to 1000,000 g / mol, 300,000 g / mol to 15 ...500,000 g / mol 400,000 g / mol, 400,000 g / mol to 1,000,000 g / mol, 400,000 g / mol to 900,000 g / mol, 400,000 g / mol to 800,000 g / mol, 400,000 g / mol to 700,000 g / mol, 400,000 g / mol to 600,000 g / mol, 400,000 g / mol to 500,000 g / mol, 500,000 g / mol to 1,000,000 g / mol 0 g / mol, 500,000 g / mol to 900,000 g / mol, 500,000 g / mol to 800,000 g / mol, 500,000 g / mol to 700,000 g / mol, 500,000 g / mol to 600,000 g / mol, 600,000 g / mol to 1,000,000 g / mol, 600,000 g / mol to 900,000 g / mol, 600,000 g / mol to 800,000 g / mol, 6 The weight average molecular weight of the present invention is 0.0 ...

[0059] Hydrogenated star polymer

[0060] Hydrogenation of star polymers involves hydrogenating the olefinic unsaturation. This process is well known and described, for example, in U.S. Pat. No. 4,141,847, which is hereby incorporated by reference.

[0061] The degree of hydrogenation may vary. In some embodiments, at least 80% (such as at least 85%, at least 90%, at least 95%, or at least 98%) of the original olefinic unsaturation is hydrogenated.

[0062] The hydrogenation is generally carried out in a suitable inert solvent using a hydrogenation catalyst such as copper or molybdenum compounds and noble metal compounds.

[0063] Examples of commercially available styrene hydrogenated diene star polymers include Infineum SV200 from Infineum USA LP and Infineum UK Ltd. TM 、Infineum SV250 TM 、Infineum SV260 TM 、InfineumSV270 TM 、Infineum SV300 TM ; Available from The Lubrizol Corporation 5994A.

[0064] Lubricating oil composition

[0065] The low SSI copolymers or homopolymers of the present disclosure can be used as additives in lubricating oils. The concentration of the viscosity modifier in the lubricating oil composition can be in the range of 0.01 to 5 wt.% (e.g., 0.5 to 5 wt.%, 0.5 to 4 wt.%, 0.5 to 3 wt.%, 0.5 to 2 wt.%, 0.5 to 1 wt.%, 1 to 5 wt.%, 1 to 4 wt.%, 1 to 3 wt.%, 1 to 2 wt.%, 2 to 5 wt.%, 2 to 4 wt.%, 2 to 3 wt.%, 3 to 5 wt.%, 3 to 4 wt.%, 4 to 5 wt.%, etc.) based on the total weight of the lubricating oil composition.

[0066] The oil of lubricating viscosity (sometimes referred to as "base stock" or "base oil") is the main liquid component of the lubricant into which additives and possibly other oils are blended, for example, to produce the final lubricant (or lubricant composition). The base oils useful for preparing the concentrates and for preparing the lubricating oil compositions therefrom may be selected from natural (vegetable, animal or mineral) lubricating oils and synthetic lubricating oils and mixtures thereof.

[0067] The definitions of base stocks and base oils in this disclosure are the same as those found in American Petroleum Institute (API) Publication 1509, 21st Edition (February 2022). Using the test methods specified in Table E-1, Group I base stocks contain less than 90% saturated hydrocarbons and / or greater than 0.03% sulfur, and have a viscosity index greater than or equal to 80 and less than 120. Using the test methods specified in Table E-1, Group II base stocks contain greater than or equal to 90% saturated hydrocarbons and less than or equal to 0.03% sulfur, and have a viscosity index greater than or equal to 80 and less than 120. Using the test methods specified in Table E-1, Group III base stocks contain greater than or equal to 90% saturated hydrocarbons and less than or equal to 0.03% sulfur, and have a viscosity index greater than or equal to 120. Group IV base stocks are polyalphaolefins (PAOs). Group V base stocks include all other base stocks not included in Group I, Group II, Group III, or Group IV.

[0068] Natural oils include animal oils, vegetable oils (e.g., castor oil and lard) and mineral oils. Animal oils and vegetable oils with good thermal oxidation stability can be used. Among natural oils, mineral oils are preferred. Mineral oils vary greatly in their crude oil sources (e.g., whether they are paraffinic, cycloparaffinic or mixed paraffinic-cycloparaffinic). Oils derived from coal or shale are also useful. Natural oils also vary in their production and purification methods (e.g., their distillation ranges) and whether they are straight run or cracked, hydrofined or solvent extracted.

[0069] Synthetic oils include hydrocarbon oils. Hydrocarbon oils include oils such as polymerized and interpolymerized olefins (e.g., polybutene, polypropylene, propylene isobutylene copolymers, ethylene-olefin copolymers, and ethylene-α-olefin copolymers). Polyalphaolefin (PAO) oil base stocks are commonly used synthetic hydrocarbon oils. For example, a C8 to C6 derivative may be used. 14 Olefins, such as C8, C 10 , C 12 , C 14 PAO of olefins or mixtures thereof.

[0070] Other useful fluids for use as base oils include non-conventional or unconventional base stocks which have been processed (preferably catalytically processed) or synthesized to provide high performance properties.

[0071] Unconventional or extra-conventional base stocks / base oils include one or more of the following: a mixture of base stocks derived from one or more natural gas to liquids (GTL) materials, and isomerate / isodewaxate base stocks derived from natural waxes or waxy feeds, mineral and or non-mineral oil waxy feeds such as slack wax, natural waxes and waxy feeds such as gas oils, waxy fuel hydrocracker bottoms, waxy raffinates, hydrocracked products, thermal cracked products or other mineral, mineral oil or even non-petroleum derived waxy materials such as waxy materials obtained from coal liquefaction or shale oil, and mixtures of such base stocks.

[0072] The base oil used in the lubricating oil composition of the present disclosure is any kind of oil corresponding to API Group I, Group II, Group III, Group IV and Group V oils and mixtures thereof, preferably API Group II, Group III, Group IV and Group V oils and mixtures thereof, more preferably Group III to Group V base oils, due to their superior volatility, stability, viscosity and cleanliness characteristics.

[0073] Typically, the base oil will have a viscosity between 1.4 and 20 mm at 100°C (ASTM D445). 2 / s (e.g., 3 to 12 mm 2 / s, 4 to 10 mm 2 / s or 4.5 to 8 mm 2 / s) range.

[0074] The lubricating oil composition of the present invention also contains conventional lubricant additives for imparting auxiliary functions to obtain a finished lubricating oil composition in which these additives are dispersed or dissolved. For example, the lubricating oil composition can be blended with antioxidants, dispersants (such as ashless dispersants), antiwear agents, detergents (such as metal detergents), rust inhibitors, demisters, demulsifiers or demulsifiers, friction modifiers, metal deactivators, pour point depressants, viscosity modifiers, antifoaming agents / defoamers, cosolvents, packaging extenders, corrosion inhibitors, dyes, extreme pressure agents, oiliness improvers, etc. and mixtures thereof. A variety of additives are known and commercially available. These additives or their analogous compounds can be used to prepare the lubricating oil composition of the present invention by conventional blending procedures.

[0075] When used, each of the aforementioned additives is used in a functionally effective amount to impart the desired properties to the lubricant. Thus, for example, if the additive is an ashless dispersant, the functionally effective amount of such ashless dispersant will be an amount sufficient to impart the desired dispersion characteristics to the lubricant. Generally, unless otherwise indicated, when used, the concentration of each of these additives may be in the range of about 0.001 to about 20 wt.%, such as about 0.01 to about 10 wt.%, about 0.1 to about 5 wt.%, and about 1 to about 4 wt.%.

[0076] Lubricating oils comprising the polymer composition may have a kinematic viscosity (as measured by ASTM D445) of at least 2 cSt (e.g., at least 3 cSt, at least 4 cSt, at least 6 cSt, at least 8 cSt, at least 10 cSt, at least 12 cSt, or at least 15 cSt) at 100° C. Likewise, lubricating oils comprising the polymer composition may have a kinematic viscosity (as measured by ASTM D445) of 200 cSt or less (e.g., 150 cSt or less, 100 cSt or less, 50 cSt or less, 40 cSt or less, 30 cSt or less, or even 20 cSt or less) at 40° C.

[0077] In one embodiment, the lubricating oil composition of the present disclosure can be identified by the viscosity standard of the Society of Automotive Engineers (SAE) for automotive lubricants. As an example, the lubricating composition is identified by the SAE J300 standard (viscosity classification of engine oils). The J300 viscosity grades of the present disclosure are summarized in Table A.

[0078] Table A

[0079]

[0080]

[0081] (1) ASTM D5293

[0082] (2) ASTM D4684

[0083] (3) ASTM D445

[0084] (4) ASTM D4683, ASTM D4741, ASTM D5481 or CEC L-36-90

[0085] (5) For 0W-40, 5W-40 and 10W-40 grades

[0086] (6)For 15W-40, 20W-40, 25W-40 and 40 grades

[0087] When the lubricating oil composition contains one or more of the above components, one or more additives are blended into the composition in an amount sufficient to allow it to perform its intended function. Typical amounts of such additives useful in the present invention are shown in Table B below.

[0088] Table B

[0089]

[0090]

[0091] Example

[0092] The fuel economy performance of lubricating oils containing a low SSI viscosity improver was tested and compared to lubricating oils containing a high SSI viscosity improver.

[0093] Tables 1 and 2 below summarize the contents of Comparative Examples 1-3 and Inventive Examples 1-5 and the results of fuel economy tests using 3 different engines. The fuel consumption or specific fuel consumption rate measured for each example or comparative example is used to calculate the fuel economy improvement (FEI) relative to a benchmark oil (sometimes referred to as a "reference oil"). The benchmark oil is used to eliminate the effects of drift in the engine during the test.

[0094] Each sample contained a viscosity modifier in the form of polymer A, B, C, D, E or F as defined herein.

[0095] Polymer A: 24SSI ethylene-based ethylene-propylene copolymer, Mw about 83,000 g / mol

[0096] Polymer B: 24SSI ethylene-based ethylene-propylene copolymer, Mw about 135,000 g / mol

[0097] Polymer C: 13SSI propylene-based ethylene-propylene copolymer, Mw about 63,000 g / mol

[0098] Polymer D: 8SSI propylene-based ethylene-propylene copolymer, Mw about 53,000 g / mol

[0099] Polymer E: 6SSI ethylene-based ethylene-propylene copolymer obtained by visbreaking, Mw about 44,000 g / mol

[0100] Polymer F: 5SSI star-shaped hydrogenated isoprene polymer, Mw about 500,000 g / mol (commercially available as SV 200)

[0101] Referring to Table 1, the comparative examples and inventive examples contained 17.06% of the additive package, 0.3 wt% of the pour point depressant, and the remainder was Gr III / IV base oil to make a 0W-20 oil. The oils were blended to the same HTHS 150°C of 2.6 cP. These SAE 0W-20 oils were tested in 2 different engines with modal and transient drive cycles, representing fluid dynamics, mixing and boundary conditions.

[0102] DD13 fuel economy test (modal mode)

[0103] The DD13 modal mode fuel economy test quantifies the fuel efficiency benefits of an engine within a specified test cycle, as described in the Heavy Duty Supplemental Emissions Test (SET), an engine dynamometer test introduced by the U.S. Environmental Protection Agency (EPA). The standard test cycle consists of 13 discrete modes (i.e., specific engine loads and RPMs) running for seven minutes to stabilize the temperature and pressure to a high level of consistency. The cycle is repeated a total of eight times, with the last seven used for statistical evaluation of the operation. The flushing process between lubricants ensures that no carryover occurs. The test rig is a modified Detroit Diesel DD13 engine. The FEI results are expressed as a percentage improvement in fuel consumption between the baseline oil (SAE 10W-30) and the candidate lubricant. The weighting factor B of SET (developed to take into account the deceleration tendency of heavy-duty engines) is used.

[0104] OM501LA Fuel Economy Test (WHTC)

[0105] The OM501LA FE test is the World Harmonized Transient Cycle (WHTC) test using the OM501 LA Daimler engine. The WHTC test is a transient engine dynamometer program defined by the proposed Global Technical Regulation (GTR) developed by the United Nations Economic Commission for Europe Rapporteur Group on Pollution and Energy (UN ECE GRPE). The test procedure for the WHTC can be found in GTR No. 4

[0106] Two representative test cycles, the transient test cycle (WHTC) with cold start and hot start requirements, have been created to cover typical driving conditions in the EU, the US, Japan and Australia. The Euro VI emission regulations for heavy-duty engines adopt the WHTC test requirements for the first time.

[0107] The WHTC is a transient test of 1800 seconds duration with several driving segments. The test procedure includes a cold start test after natural or forced engine cooling, a heat soak period and a hot start test. The FEI results are expressed as a percentage improvement in fuel consumption between a baseline oil (SAE 10W-40) and the candidate lubricant.

[0108] Table 1. SAE 0W-20 oils made with viscosity improvers A, E and F, tested in 2 different engines (DD13 and OM501LA) in modal or transient driving cycles.

[0109] Comparative Example 1 Invention Example 1 Invention Example 2 Polymer A 0.38wt% Polymer E 0.52wt% Polymer F 0.45wt% KV 100(cSt) 7.94 7.58 8.16 HTHS150(cP) 2.62 2.56 2.63 FEI-modal mode (%) 0.79 0.86 1.01 FEI-WHTC(%) 1.41 1.51 1.47

[0110] Referring to Table 2 below, the comparative examples and inventive examples contain 17.06% of the additive package, 0.3 wt% of the pour point depressant, and the remainder is Gr III / IV base oil to make a 5W-30 oil. After 30 Bosch cycles, the oil has been blended to a comparable KV 100 of 9.3 cSt. Table 2 also summarizes the results of the OM471 fuel economy test.

[0111] OM471 Fuel Economy Test (WHTC)

[0112] The OM471 FE test is the World Harmonized Transient Cycle (WHTC) test using the OM471 Daimler engine. The WHTC test is a transient engine dynamometer program defined by the proposed Global Technical Regulation (GTR) developed by the United Nations Economic Commission for Europe Rapporteur Group on Pollution and Energy (UN ECE GRPE). The test procedure for the WHTC can be found in GTR No.4.

[0113] Two representative test cycles, the transient test cycle (WHTC) with cold start and hot start requirements, have been created to cover typical driving conditions in the EU, the US, Japan and Australia. The Euro VI emission regulations for heavy-duty engines adopt the WHTC test requirements for the first time.

[0114] The WHTC is a transient test of 1800 seconds duration with several driving segments. The test procedure includes a cold start test after natural or forced engine cooling, a heat soak period and a hot start test. The FEI results are expressed as a percentage improvement in fuel consumption between a baseline oil (SAE 10W-30) and the candidate lubricant.

[0115] Table 2. SAE 5W-30 oils made with viscosity improvers A, B, C, D and F, tested in an engine (OM 471LA) operating on a transient driving cycle.

[0116]

[0117] Overall, the fuel economy improvement (FEI) of the examples made with VM having a low SSI shows a clear benefit compared to the comparative examples having a higher SSI VM.

[0118] All documents described herein are incorporated herein by reference, including any priority documents and / or test procedures, as long as they are not inconsistent with this document. As is apparent from the foregoing general description and specific embodiments, although the form of the present disclosure has been illustrated and described, various modifications may be made without departing from the spirit and scope of the present disclosure. Therefore, it is not intended that the present disclosure be limited thereby.

[0119] For the sake of brevity, only certain ranges are explicitly disclosed herein. However, the range from any lower limit can be combined with any upper limit to list a range that is not explicitly listed, and the range from any lower limit can be combined with any other lower limit to list a range that is not explicitly listed, and in the same manner, the range from any upper limit can be combined with any other upper limit to list a range that is not explicitly listed. In addition, each point or single value between the endpoints of the range is included in the range, even if it is not explicitly listed. Therefore, each point or single value can serve as its own lower limit or upper limit to be combined with any other point or single value or any other lower limit or upper limit to list a range that is not explicitly listed.

[0120] Unless otherwise stated, the phrases “consists essentially of” and “consisting essentially of” do not exclude the presence of other steps, elements or materials, whether specifically mentioned or not, in the specification, as long as such steps, elements or materials do not affect the basic and novel characteristics of the disclosure, and further, they do not exclude impurities and variations normally associated with the elements and materials used.

[0121] Likewise, the term “comprising” is considered synonymous with the term “including.” Likewise, whenever a composition, an element, or a group of elements is preceded by the transitional phrase “comprising,” it is understood that we also contemplate the same composition or group of elements preceded by the transitional phrases “consisting essentially of,” “consisting of,” “selected from the group consisting of,” or “being,” and vice versa.

[0122] As used herein, the terms "a", "an" and "the" should be construed to cover the plural as well as the singular.

[0123] Various terms have been defined above. If a term used in a claim is not defined above, it should be given the broadest definition that persons in the relevant art have given that term as reflected in at least one printed publication or issued patent. In addition, all patents, test procedures, and other documents cited in this application are fully incorporated by reference to the extent such disclosure is not inconsistent with this application and for all jurisdictions in which such incorporation is permitted.

[0124] The foregoing description of the present disclosure illustrates and describes the present disclosure. In addition, the present disclosure shows and describes only preferred embodiments, but as mentioned above, it should be understood that the present disclosure can be used in various other combinations, modifications and environments, and can be changed or modified within the scope of the concepts as expressed herein, commensurate with the above teachings and / or the skills or knowledge of the relevant art. Although the foregoing is related to embodiments of the present disclosure, other and further embodiments of the present disclosure can be designed without departing from the basic scope of the present disclosure, and the scope of the present disclosure is determined by the appended claims.

[0125] The embodiments described above are further intended to explain the best known modes of practicing it and to enable others skilled in the art to utilize the present disclosure in such or other embodiments and with various modifications required for a particular application or use. Therefore, this specification is not intended to be limited to the forms disclosed herein. In addition, the appended claims are intended to be interpreted as including alternative embodiments.

Claims

1. A method for improving the fuel economy of an engine, the method comprising: The engine is lubricated with a lubricating oil composition, the lubricating oil composition comprising: a) oil of lubricating viscosity; and b) a viscosity improver comprising an olefin copolymer or a diene-based copolymer or homopolymer, wherein the viscosity improver has a shear stability index of 15 or less; The lubricating oil composition contains substantially no viscosity improver other than the viscosity improver of b).

2. The method of claim 1, wherein the lubricating oil composition is substantially free of polyalkyl methacrylate (PMA) viscosity improvers.

3. The method of claim 1, wherein the viscosity improver is linear or star-shaped.

4. The method of claim 3, wherein the radial diene polymer has a weight average molecular weight of about 300,000 g / mol to 1,000,000 g / mol.

5. The method of claim 1, wherein the olefin copolymer is an ethylene-propylene copolymer.

6. The method of claim 5, wherein the ethylene-propylene based copolymer has a weight average molecular weight of about 10,000 g / mol to about 100,000 g / mol.

7. The method of claim 5, wherein the ethylene-propylene based copolymer has an ethylene content of 35 to 70 wt% or 2 to 20 wt.%, based on the weight of the copolymer.

8. The method of claim 1, wherein the diene-based copolymer or homopolymer is hydrogenated.

9. The method of claim 1 wherein the viscosity modifier is a styrene hydrogenated diene copolymer.

10. The method of claim 1, wherein the improvement in fuel economy is determined based on a fuel economy improvement (FEI) as measured from a World Harmonized Transient Cycle or a Heavy Duty Supplemental Emissions Test modal mode dynamometer test.

11. A method for improving the fuel economy of a diesel engine, the method comprising: The diesel engine is lubricated with a lubricating oil composition, the lubricating oil composition comprising: a) oil of lubricating viscosity; and b) a viscosity improver comprising an olefin copolymer or a diene-based copolymer or homopolymer, wherein the viscosity improver has a shear stability index of 15 or less; The lubricating oil composition contains substantially no viscosity improver other than the viscosity improver of b).

12. The method of claim 11, wherein the lubricating oil composition is substantially free of polyalkyl methacrylate (PMA) viscosity improvers.

13. The method of claim 11, wherein the viscosity improver is linear or star-shaped.

14. The method of claim 11, wherein the viscosity modifier is an ethylene-propylene based copolymer.

15. The method of claim 11, wherein the hydrogenated diene polymer has a weight average molecular weight of about 300,000 to 1,000,000 g / mol.

16. The method of claim 14, wherein the ethylene-propylene based copolymer has a weight average molecular weight of about 10,000 g / mol to about 100,000 g / mol.

17. The method of claim 14, wherein the ethylene-propylene based copolymer has an ethylene content of 35 to 70 wt% based on the weight of the copolymer.

18. The method of claim 14, wherein the ethylene-propylene based copolymer has an ethylene content of 2 to 20 wt% based on the weight of the copolymer.

19. The method of claim 11, wherein the hydrogenated diene polymer is a styrene hydrogenated diene copolymer.

20. The method of claim 11, wherein the improvement in fuel economy is determined based on a fuel economy improvement (FEI) as measured from a World Harmonized Transient Cycle or a Heavy Duty Supplemental Emissions Test modal mode dynamometer test.

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