JP2009138195A - Lubricant composition comprising bi-modal side-chain distribution lofi - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant composition having improved fluidity, particularly low-temperature fluidity. <P>SOLUTION: The lubricant composition includes (a) an API Group III base stock, (b) at least one semi-crystalline viscosity modifier and (c) at least one LOFI having a side-chain distribution satisfying the following requirements: (1) the distribution contains C<SB>8</SB>-C<SB>18</SB>side chains with an average number of carbons ranging from 12.4 to 14.4; (2) the side chain distribution is bi-modal with a lower portion of the bi-modal distribution made up primarily of C<SB>12</SB>and an upper portion of the distribution made up primarily of C<SB>16</SB>, C<SB>18</SB>or combinations thereof; (3) the total mol% of the upper portion of the distribution must be less than that of the lower portion of the distribution; and (4) the amount of C<SB>12</SB>on the side chain must be at least 40 mol% of the total side chain distribution amount. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to lubricating oil compositions having improved fluidity, and particularly to lubricating oil compositions comprising the American Petroleum Institute (API) Group III base stock exhibiting improved low temperature fluidity.

Lubricating oil compositions are used in various applications such as automotive applications and industrial applications. Lubricating oil compositions are typically formulated from a base stock and one or more additives.
Various additives for use in lubricating oil compositions are known in the art. Examples of such additives include, but are not limited to, lubricating oil flow improvers (LOFI), viscosity modifiers (VM), and the like.
Automakers and government authorities have introduced new, more stringent performance requirements for lubricants. Examples are requirements for oil volatility and fuel efficiency. These changes have made the selection of one or more base stocks used in lubricants much more important than they have been in the past. Due to their low viscosity and low volatility, API Group III base stocks have become the base stock of choice for next generation lubricating oil compositions.

The present invention provides an improved cold flow comprising (a) an API Group III base stock, (b) a semi-crystalline viscosity modifier, and (c) one or more LOFIs having a side chain distribution that satisfies certain requirements. Lubricating oil compositions having performance characteristics are provided.
In a non-limiting embodiment, the present invention is one or more LOFIs having (a) an API Group III base stock, (b) a semi-crystalline viscosity modifier, and (c) a side-chain distribution. The side chain distribution includes the following requirements: (1) the side chain includes a C ₈ to C ₁₈ side chain with an average carbon number ranging from 12.4 to 14.4; The distribution is bimodal with the lower part of the bimodal distribution composed mainly of C ₁₂ and the upper part of the distribution composed mainly of C ₁₆ , C ₁₈ or combinations thereof, (3) the sum of the upper part of the distribution The side chain distribution satisfying that the mole% must be less than that at the bottom of the distribution and (4) the amount of C _{12 in} the side chain must be at least 40 mole% of the total side chain distribution. A lubricating oil composition comprising one or more LOFIs.

Unless otherwise indicated, all numerical values used in the specification and claims, including amounts of ingredients, reaction conditions, dimensions, physical properties, processing parameters, etc., are modified in all cases by the term “about”. It should be understood that Accordingly, unless indicated to the contrary, the numerical values set forth in the following specification and claims may vary depending upon the desired properties sought to be obtained by the present invention. At least not in an attempt to limit the application of the doctrine of equivalents of the claims, but in light of the number of significant Arabic numerals reported and at least interpreted by applying conventional rounding techniques. It should be. Further, all ranges disclosed herein are to be understood to include the first and last range values and any and all subranges subsumed therein. For example, a range described as “1-10” begins with any subrange between a minimum value of 1 and a maximum value of 10 (and includes a minimum value and a maximum value), ie, a minimum value of 1 or more, It should be considered to include all subranges ending with the following maximum values, for example 5.5-10. Any reference to a US patent or patent document or document in the following description is also to be understood to include that document in its entirety by reference herein.
As used herein, the following terms are defined as described below.
The term “polymer” includes copolymers unless specifically stated to be limited to polymers derived from single monomer polymerization only, and includes linear polymers as well as branched polymers.

The term “copolymer” refers to a polymer obtained from the polymerization reaction of two chemically different monomers. With respect to ethylene alpha olefin copolymers, it is understood that such copolymers may optionally contain minor amounts (eg, greater than zero weight percent but less than 10 weight percent) of non-conjugated polyenes, in which case the copolymer is occasionally It is called a polymer. With respect to ethylene alpha olefins, it is understood that both copolymers and terpolymers of ethylene and at least one other alpha-olefin are included.
The term “average carbon number” refers to the average carbon number weighted by the mole fraction.
The term “lubricating oil flow improver” (LOFI) is measured by tests such as improved cryogenic handling, pumpability and / or pour point, mini-rotary viscometer (MRV), and scanning Brookfield viscometer. It includes all additives that modify the size, number, and growth of wax crystals in the lubricating oil (or lube for short) in such a way as to impart the vehicle operability that is achieved. The majority of lube oil flow improvers are polymers or copolymers, or include polymers or copolymers. These polymers are generally side chains, main chains or mixtures thereof.
The term “base oil” refers to a refined liquid that is free of additives and is used as a component in a lubricating oil blend.
The term “base stock” refers to a base oil blend, mixture, or the like.
Various “groups” of base stock are referred to herein, eg, API Group III base stock. These group classifications have been established by the American Petroleum Institute (API) according to the tables contained in US Pat. No. 6,475,963, which is hereby incorporated by reference.
The term “bimodal” refers to a carbon chain length frequency distribution with two distinct peaks (or modes), each peak having a carbon chain length (or a continuous even number of moles) that is higher than the adjacent carbon chain length. Adjacent carbon chain length with respect to carbon). The bimodal carbon chain length frequency distribution has a “lower distribution” and an “upper distribution”.

The term “bottom of distribution” refers to a portion of a bimodal distribution that includes modes with low carbon chain length and low mole percent adjacent carbon chain length (with respect to consecutive even chain lengths). Highest carbon chain length in the lower part of the distribution is C _14.
The term “upper distribution” refers to a portion of a bimodal distribution that includes modes with high carbon chain length and low mole percent adjacent carbon chain length. Minimum carbon chain length in the upper part of the distribution is C _16.
The term “primarily” means that the amount of one component present in a composition, compound, etc. is greater than the amount of any other component present on a component-by-component basis.
The present invention is a lubricating oil composition comprising (a) a Group III base stock, (b) a semi-crystalline viscosity modifier, and (c) one or more LOFIs that meet certain standards.
According to the present invention, the lubricating oil composition comprises API Group III base stock. Group III base stocks defined by the API have an open-ended viscosity index. In a non-limiting embodiment of the present invention, the base stock has a viscosity index greater than 120. In another non-limiting embodiment of the present invention, the base stock has a viscosity index of 120 and 200. Basestock Visom brand commercially available from ExxonMobil (Fauley, UK) as the preferred commercially available Group III basestock; Yubase brand of basestock commercially available from SK Corporation (Ulsan, Korea) (Yubase brand); Base-stock Ultra-S brand commercially available from ConocoPhillips (Westlake, LA (USA)); and Basestock nexus commercially available from Nest (Porvoo, Finland) Examples include, but are not limited to, the Nexbase brand.
In a non-limiting embodiment of the invention, the base stock is made using a synthetic gas oil (gas-to-liquids (“GTL”)) process. GTL is a purification method used to convert natural gas or other gaseous hydrocarbons to long chain hydrocarbons. For example, GTL can be used to convert methane-rich gas to liquid fuel by direct conversion or synthesis gas as an intermediate using a Fischer-Tropsch process. As is known in the art, an isomerization catalyst can be used with GTL to create a Group III base stock.

According to the present invention, the lubricating oil composition includes a semi-crystalline viscosity modifier. Typically, the semicrystalline viscosity modifier comprises one or more high molecular weight hydrocarbon polymers as are known in the art. As examples of suitable hydrocarbon polymers, at least one additional alpha olefin monomer having 3 to 30, for example 3 to 8 carbon atoms, which may be linear or branched And copolymers of ethylene copolymerized with). If necessary, low concentrations of non-conjugated dienes may be present, for example, less than about 10% by weight. In a non-limiting embodiment, these copolymers are those comprising ethylene and propylene. Ethylene copolymers suitable for the present invention include not only tapered or block copolymers (including terpolymers, tetrapolymers, etc.), but also controlled compositions within and within copolymer chains known in the art. Having homogeneity and / or heterogeneity. Such copolymers are “Polymers as Rheology Modifiers” by G. VerStrate, MJ Struglinski, edited by DN Schulz and JE Glass, American Chemical Society, Washington DC, 1991 “Lubricant viscosity modifiers” As a polymer ”; Chapter 15 (Chapter 15). The above literature is included in this specification as a reference to the extent permitted.
In a non-limiting embodiment of the invention, the semi-crystalline viscosity modifier is an oil-soluble polymer comprising ethylene and a C _{3 to} C ₁₈ alpha-olefin, the polymer being characterized by a combination of the following parameters: (a) An average ethylene content within the range of 60-80 mol% (the polymer contains no more than 1.3 wt% polymer fraction insoluble in normal decane at 45 ° C.), (b) a degree of crystallinity of less than 25%, (c A ratio of weight average molecular weight / number average molecular weight of less than 4.0, and (d) a viscosity average molecular weight in the range of 10,000 to 200,000 daltons. See US Pat. No. 3,551,336, which is hereby incorporated by reference.
In another non-limiting embodiment of the invention, the semi-crystalline viscosity modifier is a segmented copolymer of ethylene and at least one other alpha-olefin monomer, each copolymer being heterogeneous within the molecule, And at least one segment of the copolymer that is homogeneous between molecules and constitutes at least 10% of the chain of the copolymer is a crystallizable segment. See U.S. Pat. No. 4,804,794, which is included by reference.

In a non-limiting embodiment of the invention, a semicrystalline viscosity modifier is included in combination with an amorphous viscosity modifier. Examples of this are first copolymers of ethylene and C _{3 to} C ₁₈ alpha-olefins with an ethylene content of 50-95 mol% and ethylene and C _{3 to} C ₁₈ higher alpha-olefins with an ethylene content of 5-80 mol% Wherein the ethylene content of the first copolymer is at least 5 mole percent greater than the ethylene content of the second polymer. See US Pat. No. 3,697,429, which is hereby incorporated by reference.
In a non-limiting embodiment of the invention, the semicrystalline viscosity modifier has a number average molecular weight in the range of 20,000 to 500,000 daltons, such as 25,000 to 400,000 daltons or 30,000 to 300,000 daltons, as measured by gel permeation chromatography.
The semicrystalline viscosity modifier may be present in the lubricating oil composition in an amount ranging from 0.05 to 5% by weight of the polymer.
According to the present invention, the lubricating oil composition comprises one or more LOFIs having a side chain distribution that satisfies the following requirements:
(1) Each side chain present is composed of 8 to 18 carbon atoms with an average carbon number of 12.4 to 14.4, for example 12.8 to 14.0 or 13.0 to 13.8 Containing carbon chains,
(2) The lower part of the bimodal distribution composed mainly of C ₁₂ and the upper part of the distribution composed mainly of C ₁₆ , C ₁₈ or a combination thereof (ie a distribution having a high carbon number mode) Is bimodal,
(3) The total mol% at the top of the distribution must be less than that at the bottom of the distribution, and
(4) the amount of C ₁₂ side chains, at least 40 mole percent of the total side chain distribution, for example, should be at least 50 mol% or at least 60 mole%.

In a non-limiting embodiment where the essential components of the bimodal distribution consist of (a) C ₁₂ and C ₁₆ or (b) a mixture of C ₁₂ , C ₁₆ and C ₁₈ , the amount of C ₁₄ is the total side chain distribution It should be less than 20 mol%, for example less than 10 mol%.
In a non-limiting embodiment of the invention, the side chain comprises an even number of carbon number segments ranging from C ₈ to C ₁₈ , ie C ₈ , C ₁₀ , C ₁₂ , C ₁₄ , C ₁₆ , C ₁₈ .
In a non-limiting embodiment, the LOFI is a dialkyl fumarate-vinyl acetate copolymer. Dialkyl fumarate-vinyl acetate copolymers have carbon numbers in the range of 8 to 18, with an average carbon number of 12.4 to 14.4, for example 12.8 to 14.0, or 13.0 to 13.8 From a mixture of alcohols having The copolymer is a side chain copolymer having methylene segments as side chains.
These LOFIs can contain pendant ester groups derived from a mixture of alcohols, whose alcohol residues are characterized as repeating methylene units, which generally range from 50,000 to 350,000 daltons as measured by gel permeation chromatography. An oil-soluble or dispersible polymer composition having a weight average molecular weight of
In a non-limiting embodiment of the invention, the dialkyl fumarate-vinyl acetate copolymer has a specific viscosity in the range of 0.3 to 1.5, such as 0.3 to 1.0 or 0.45 to 0.7. In another non-limiting embodiment, the dialkyl fumarate-vinyl acetate copolymer has a weight average molecular weight ranging from 50,000 to 350,000 daltons, such as from 50,000 to 200,000 daltons or from 75,000 to 120,000 daltons.

In another non-limiting embodiment, the LOFI comprises a poly (alkyl methacrylate) polymer. The poly (alkyl methacrylate) polymer comprises a copolymer (A) consisting essentially of alkyl methacrylate (a1) and one or more monomers (a2). See US Pat. No. 5,891,831, which is hereby incorporated by reference.
The amount of alkyl methacrylate (a1) constituting the copolymer (A) may generally be 30 to 99.99% by weight relative to the weight of the copolymer (A).
The alkyl methacrylate (a1) is generally a methacrylate having a linear alkyl group having 1 to 18 carbon atoms (for example, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, Tetradecyl methacrylate, pentadecyl methacrylate, hexadecyl methacrylate, octadecyl methacrylate). Of these, alkyl methacrylates in which the alkyl moiety has from 8 to 18 carbon atoms are preferred.
The monomer (a2) is at least one selected from the group consisting of conjugated dienes, acetylenes, substituted acetylenes, alkyl vinyl ethers and alkyl allyl ethers. The amount of monomer (a2) constituting the copolymer (A) may generally be 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on the weight of the copolymer (A).
In yet another non-limiting embodiment, the LOFI comprises a poly (alkyl acrylate) polymer. The poly (alkyl acrylate) polymer is an acrylate or alkyl acrylate copolymer derivative having a dispersing group. See US Pat. No. 6,869,919, which is hereby incorporated by reference.
In another non-limiting embodiment, the LOFI comprises a poly (styrene-dialkyl maleate) polymer. See US Pat. No. 4,564,438, which is hereby incorporated by reference.
LOFI and one or more other ingredients (excluding base stock) in the lubricating oil composition are referred to as “additives”.

In a non-limiting embodiment, the LOFI has a weight average molecular weight, as measured by gel permeation chromatography, ranging from 50,000 to 350,000 daltons, such as from 80,000 to 200,000 daltons.
In another non-limiting embodiment, the LOFI has a specific viscosity in the range of 0.3 to 1.0, such as 0.4 to 0.8.
LOFI may be present in the lubricating oil composition in an amount ranging from 0.005 to 1.0% by weight, for example 0.05 to 0.5% by weight.
The lubricating oil composition of the present invention further comprises one or more optional components: corrosion inhibitors, antioxidants, friction modifiers, dispersants, antifoaming agents, antiwear agents, detergents, rust inhibitors. Etc.
In a non-limiting embodiment, the lubricating oil composition of the present invention includes a corrosion inhibitor. Corrosion inhibitors (also known as anti-corrosion agents) reduce the deterioration of the metal parts that are contacted by the lubricating oil composition. Examples of corrosion inhibitors are phosphosulfurized hydrocarbons and preferably in the presence of alkylated phenols or alkylated phenol thioesters, and also preferably in the presence of carbon dioxide and phosphated hydrocarbons and alkaline earth metal oxides or hydroxides. It is a product obtained by reaction of the product. Phosphosulfurized hydrocarbons suitable hydrocarbon, for example, terpenes, C ₂ -C ₆ olefin polymers, for example, heavy petroleum fraction of 150 ° F~600 ° F polyisobutylene range of (66 ℃ ~316 ℃) Prepared by reacting with 5-30 wt% phosphorus sulfide at temperature for 0.5-15 hours. Neutralization of the phosphosulfurized hydrocarbon may be performed in the manner taught in US Pat. No. 1,969,324.

In a non-limiting embodiment, the lubricating oil composition of the present invention can include an antioxidant. Antioxidants alleviate the tendency of mineral oil to deteriorate during use, which deterioration can be evidenced by products of oxidation, such as deposits such as sludge and varnish on metal surfaces, and thickening. As such an antioxidant, preferably an alkaline earth metal salt of an alkylphenol thioester having a C _{5 to} C ₁₂ alkyl side chain, such as nonylphenol calcium sulfide, t-octylphenyl barium sulfide, dioctylphenylamine, phenyl alpha naphthylamine, Examples thereof include phosphosulfurized hydrocarbons and sulfurized hydrocarbons.
In a non-limiting embodiment, the lubricating oil of the present invention includes a friction modifier. Friction modifiers can be used to impart suitable friction properties to lubricating oil compositions, such as automatic transmission fluids. Representative examples of suitable friction modifiers are U.S. Pat.No. 3,933,659, which discloses fatty acid esters and amides, U.S. Pat.No. 4,176,074, which describes a molybdenum complex of polyisobutenyl succinic anhydride-aminoalkanol, glycerol esters of dimerized fatty acids U.S. Pat.No. 4,105,571 disclosing alkanephosphonates, U.S. Pat. U.S. Pat.No. 3,852,205 disclosing succinamic acid and mixtures thereof; U.S. Pat.No. 3,879,306 disclosing N- (hydroxyalkyl) alkenyl-succinamic acid or succinimide; reaction formation of di- (lower alkyl) phosphite and epoxide US Patent No. No. 3,932,290 and US Pat. No. 4,028,258 which discloses alkylene oxide adducts of phosphorylated N- (hydroxyalkyl) alkenyl succinimides. Preferred friction modifiers include hydrocarbyl-substituted succinic acid or anhydride succinic acid esters, or their metal salts and thiobisalkanols as described in U.S. Pat.No. 4,344,853, as well as various molybdenum compounds. It is done.
In a non-limiting embodiment, the lubricating oil composition of the present invention includes a dispersant. The dispersant keeps the compounds resulting from oxidation in use that are insoluble or substantially insoluble in oil suspended in the liquid, thus preventing sludge flocculation and precipitation or deposition on metal parts. Suitable dispersants include high molecular weight alkyl succinates, reaction products of oil-soluble polyisobutylene succinic anhydrides and ethylene amines such as tetraethylenepentamine and their borates.
In a non-limiting embodiment, the lubricating oil composition of the present invention includes a component to provide foam control. Foam control is provided by polysiloxane type antifoams such as silicone oil and polydimethylsiloxane.

In a non-limiting embodiment, the lubricating oil composition of the present invention includes an antiwear agent. Antiwear agents, as their name implies, reduce wear on metal parts. Typical antiwear agents are zinc dialkyldithiophosphates and zinc diaryldithiophosphates.
In a non-limiting embodiment, the lubricating oil composition of the present invention comprises a detergent and a metal rust inhibitor. Detergents and metal rust inhibitors include metal salts of sulfonic acids, alkylphenols, sulfurized alkylphenols, alkyl salicylates, naphthenates, and other oil-soluble mono- and dicarboxylic acids. Highly basic (ie, overbased) metal salts, such as highly basic alkaline earth metal sulfonates (especially Ca and Mg salts) are frequently used as detergents. Representative examples of such materials and methods for their preparation can be found in US Pat. No. 6,127,321 based on the application originally filed on July 11, 1985.
The lubricating oil compositions of the present invention are made using methods and techniques known in the art. The lubricating oil composition of the present invention is typically made by blending the individual components into a base stock. For example, the ingredients can be added directly to the base stock by dispersing or dissolving the additive at the desired concentration level at room temperature or elevated temperature.

The invention is illustrated by the following non-limiting examples. In the examples, the lubricating oil composition is a Group III base stock (Yubase base stock), a semi-crystalline viscosity modifier (Palaton 8451 from Chevron Oronito), and LOFI (this is prepared as described below) Was included). Each lubricating oil composition contained a different LOFI. For example, the lubricating oil composition of Example 1 includes LOFI 1, the lubricating oil composition of Example 2 includes LOFI 2, and so on.
First, five LOFIs (LOFI 1-) were prepared by making five dialkyl fumarate monomers (dialkyl fumarate monomers 1-5) using a blend of alcohols having the carbon atom distribution shown in Table 1. 5) was prepared. Dialkyl fumarate monomer 1 is prepared using alcohol 1 in Table 1, dialkyl fumarate monomer 2 is prepared using alcohol 2 in Table 1, and so on. 232 g of fumaric acid, 824 g of a specific alcohol blend, and 0.2 g of Fascat 4100® were added to a round bottom flask equipped with a Dean-Stark apparatus. The slurry was stirred under a stream of nitrogen and gradually heated to 220 ° C. The esterification reaction was monitored by measuring the amount of water collected in the Dean-Stark trap. When water generation ceases (typically 4-6 hours), the dialkyl fumarate monomer is decanted from the reactor for neutralization (2.0 mg KOH / g) and saponification (223 mg KOH / g) analyzed. Dialkyl fumarate monomers 1-5 were produced by this method.
The LOFI was then prepared by making a dialkyl fumarate-vinyl acetate copolymer from a dialkyl fumarate monomer (generated in the above step) as described below. Dialkyl fumarate vinyl acetate copolymer 1 was prepared using dialkyl fumarate monomer 1, dialkyl fumarate vinyl acetate copolymer 2 was prepared using dialkyl fumarate monomer 2, and so on. 150 g of dialkyl fumarate monomer (dialkyl fumarate monomer 1-5) was added to a 300 cm ³ stainless steel reactor, Parr® brand. The reactor was sealed, heated to 50 ° C. and flushed with nitrogen for 10 minutes. 26.5 g of deoxygenated vinyl acetate was then injected into the Pearl® reactor containing the dialkyl fumarate monomer. The mixture was stirred for 15 minutes and then heated to a reaction temperature of 100 ° C. 0.26 g of tert-butyl peroctoate was dissolved in 2.0 g of Soneborn Brandol® white mineral oil and then poured into the mixture. The mixture was stirred for 5-8 hours to complete the polymerization reaction. The copolymer was then poured from the reactor into a round bottom flask and the volatiles were stripped on a rotary evaporator. Dialkyl fumarate vinyl acetate copolymers 1-5 were produced in this way.
Dialkyl fumarate vinyl acetate copolymer 1-5 blended with Group III base stock (Yubase base stock) and semi-crystalline viscosity modifier (Palaton 8451 from Chevron Oronito) as known in the art The SAE 5W-30 lubricating oil composition of Example 1-5 was produced.
In Table 1 below, composition information is presented for the LOFI side chain for Examples 1-5.

  As mentioned earlier, the LOFI side chain of the present invention needs to meet certain requirements. Various requirements are listed in Table 2 below. For various exemplary lubricating oil compositions made in the above manner (Examples 1-5), “v” appears in the box when the LOFI meets the requirements and “X” the LOFI does not meet the requirements Appear in the box.

As can be seen, the LOFI in the lubricating oil composition of Examples 1-3 meets all of the requirements and is included by the present invention. The LOFI in the lubricating oil compositions of Examples 4 and 5 does not meet all of the requirements and is outside the scope of the present invention.
The lubricating oil composition of Examples 1-5 was subjected to MRV pumpability testing according to ASTM D 4684. The results of the test are shown in Table 3.

-Means that yield stress and viscosity were not tested.
In order to pass the MRV pump transportability test, the lubricating oil composition must exhibit a viscosity of 60,000 mPa · s or less and a yield stress of less than 35 Pa. At a treatment rate of 0.50%, only Examples 1 and 3 passed the MRV pumpability test. At a treatment rate of 0.20%, only Example 1-3 passes the MRV pump transportability test. As stated above, Examples 1-3 are encompassed by the present invention.

Claims (12)

(a) API Group III base stock,
(b) one or more semicrystalline viscosity modifiers, and
(c) one or more LOFIs having a side chain distribution, wherein the side chain distribution has the following requirements:
(1) The distribution includes side chains ranging from C ₈ to C ₁₈ with an average carbon number ranging from 12.4 to 14.4;
(2) side chain distribution, is mainly the lower and mainly C _16, C ₁₈ or bimodal with a top of該分fabric composed of combinations of bimodal distribution consisting of C _12,
(3) The total mol% at the top of the distribution must be less than that at the bottom of the distribution, and
(4) one or more LOFIs having said side chain distribution satisfying that the amount of C _{12 in} the side chain needs to be at least 40 mol% of the total side chain distribution
A lubricating oil composition comprising:   The lubricating oil composition of claim 1, wherein the semicrystalline viscosity modifier comprises an amorphous viscosity modifier.   The lubricating oil composition of claim 1, wherein the LOFI is a dialkyl fumarate-vinyl acetate copolymer. The lubricating oil composition of claim 1, wherein the distribution comprises side chains ranging from C ₈ to C ₁₈ with an average carbon number ranging from 12.8 to 14.0.   The lubricating oil composition of claim 1, wherein the semi-crystalline viscosity modifier comprises a copolymer of ethylene copolymerized with at least one additional alpha olefin monomer having from 3 to 30 carbon atoms.   The lubricating oil composition of claim 1, wherein the semicrystalline viscosity modifier comprises an ethylene alpha olefin copolymer comprising a minor amount of one or more non-conjugated dienes.   The lubricating oil composition of claim 1, wherein the LOFI comprises a poly (alkyl methacrylate) polymer.   The lubricating oil composition of claim 1, wherein the LOFI comprises a poly (alkyl acrylate) polymer.   The lubricating oil composition of claim 1, wherein the LOFI comprises poly (styrene-dialkyl maleate).   The lubricating oil composition of claim 1, wherein the LOFI has a specific viscosity in the range of 0.3 to 1.0.   The lubricating oil composition of claim 1, wherein LOFI is present in an amount ranging from 0.005 wt% to 1.0 wt%, based on the total weight of the lubricating oil composition.   The lubricating oil composition according to claim 1, further comprising one or more of the following components: a corrosion inhibitor, an antioxidant, a friction modifier, and a dispersant.