JP2018087353A - Marine engine lubrication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a formulation of bright stock-free MDCL and TPEO at reduced cost.SOLUTION: The present invention provides a lubricating oil composition for a two-stroke or four-stroke marine engine, the lubricating oil composition comprising a major amount of oil of lubricating viscosity and (A) additives respectively in minor amounts; and (B) a viscosity modifier in the form of a polymer comprising a core and a plurality of polymeric arms extending from the core. Preferably, bright stock is completely or substantially absent in the composition.SELECTED DRAWING: None

Description

  The present invention relates to the lubrication of two-stroke and four-stroke marine diesel internal combustion engines, i.e. the former is usually called a crosshead engine and the latter is called a trunk piston engine. Thus, typical lubricants are commonly known as marine diesel cylinder lubricants (“MDCL”) and trunk piston engine oil (“TPEO”).

The crosshead engine is a low-speed engine having a high output region to an ultra high output region. The engine was lubricated by two individually lubricated parts: a piston / cylinder assembly lubricated with total loss lubrication with high viscosity oil (MDCL); and a low viscosity lubricant commonly referred to as system oil Includes crankshaft.
Trunk piston engines can be used in marine, power generation, and railway traction applications and are faster than crosshead engines. A single lubricant (TPEO) is used for crankcase and cylinder lubrication. All major moving parts of the engine, namely the main and big end bearings, the camshaft, and the valve gear are lubricated using a pumped circulation system. The cylinder liner is lubricated partly by splash lubrication and partly by oil from the circulation system that finds a way through the holes in the piston skirt through the connecting rod and gadion pin to the cylinder wall. .
The inclusion of bright stock in MDCL and TPEO is known in the art, and this bright stock is a highly viscous oil that is highly refined and dewaxed and produced from residual stock or bottom. Bright stock, such as generally 28~36mm ² s solvent extracted deasphalted the product from the vacuum residue having a kinematic viscosity of ¹ at 100 ° C., for example greater than 25 at 100 ° C., typically 30 mm ² s ^-1 greater The kinematic viscosity may be as follows.
However, bright stock is expensive and the art describes alternative methods. WO 99/64543 describes MDCL formulated without bright stock, and US 2008/0287329 describes TPEO containing little or no bright stock.

WO 99/64543 US 2008/0287329

  The challenge in the art is to formulate MDCL and TPEO without bright stock at a reduced cost. Another challenge in the art is to formulate MDCL and TPEO without bright stock at a reduced cost while providing improved wear resistance properties.

We have finally found that the above problems can be overcome by using star polymers such as amorphous styrene-diene copolymers in MDCL and TPEO.
Accordingly, the present invention provides a large amount of oil of lubricating viscosity,
(A) a small amount of each additive;
(B) a two-stroke or four-stroke marine engine lubricant composition comprising a core and a viscosity modifier in the form of a polymer comprising a plurality of polymer arms extending therefrom in an amount ranging from 0.05 to 6% by weight. A composition comprising less than 0.5 wt.%, Preferably less than 0.1 wt.% Of bright stock; preferably providing a composition that is completely or substantially free of bright stock.

Other aspects of the invention include:
Contains less than 0.5 wt% bright stock, preferably less than 0.1 wt%; preferably bright stock is not present or substantially absent in marine diesel cylinder lubricant or trunk piston engine oil, Use of a viscosity modifier (B) to improve the wear resistance properties of marine diesel cylinder lubricants or trunk piston engine oils;
A method of lubricating a crosshead marine diesel engine comprising supplying a composition to an engine piston / cylinder assembly;
A method of lubricating a trunk piston marine diesel engine comprising supplying a composition to the engine; and a two stroke or four stroke marine vessel comprising a large amount of oil of lubricating viscosity and (A) a small amount of each additive. A method for reducing or reducing the amount of bright stock in engine lubricating oil compositions, wherein a part or all of the bright stock is (B) in an amount ranging from 0.05 to 6% by weight Replacing the viscosity modifier in the form of a polymer comprising a core and a plurality of polymer arms extending therefrom.

As used herein, the following words and expressions have the meanings considered as and when used:
“Active ingredients” or “(ai)” refers to additive materials that are not diluents or solvents;
“Comprising” or any synonym specifies the presence of the feature, step, or integer, or component being described, but one or more other features, steps, integers, components, or It does not exclude the presence or addition of those groups; the expression “consists of” or “consists essentially of” or similar terms, “includes” or similar terms Wherein “consisting essentially of” is recognized to include substances that do not materially affect the characteristics of the composition to which it is applied;
“Major amount” means 40 or 50% by weight or more of the composition;
“Minor amount” means less than 50% by weight of the composition;
“TBN” means the total alkali number as measured by ASTM D2896.
Further herein, when and when used:
“Calcium content” is measured by ASTM 4951;
“Phosphorus content” is measured by ASTM D5185;
"Sulfate ash content" is measured by ASTM D874;
"Sulfur content" is measured according to ASTM D2622.
“KV100” means the kinematic viscosity measured by ASTM D445 at 100 ° C.
Also, the various components used are essential as well as optimal and conventional and may react under the conditions of formulation, storage, or use, and the present invention provides for any such reaction. It will also be understood that the resulting product is or provides the resulting product.

  Further, it is understood that any upper and lower amount, range, and ratio set forth herein may be independently combined.

The features of the present invention will now be discussed in more detail below.
(Oil of lubricating viscosity)
The lubricant composition contains a significant proportion of oil of lubricating viscosity. Such lubricating oils may range from light distillate mineral oil to heavy lubricating oil viscosity ranges. In general, the viscosity of the oil ranges from ² to 40, such as from 3 to 15 mm ² / sec when measured at 100 ° C., and the viscosity index ranges from 80 to 100, such as from 90 to 95. The lubricating oil may constitute more than 60% by weight of the composition, typically more than 70% by weight.
Natural oils include animal oils and vegetable oils (eg, castor oil, lard oil); liquid petroleum and hydrorefined, solvent-treated or acid-treated mineral oils of the paraffin, naphthene, and mixed paraffin-naphthene type. included. Oils of lubricating viscosity derived from coal or shale also function as useful base oils.
Synthetic lubricating oils include polymerized and copolymerized olefins (eg, polybutylene, polypropylene, propylene-isobutylene copolymer, chlorinated polybutylene, poly (1-hexene), poly (1-octene), poly (1-decene)); alkylbenzenes (Eg dodecylbenzene, tetradecylbenzene, dinonylbenzene, di (2-ethylhexyl) benzene); polyphenyls (eg biphenyl, terphenyl, alkylated polyphenols); alkylated diphenyl ethers and alkylated diphenyl sulfides, and And hydrocarbon oils and halo-substituted hydrocarbon oils, such as derivatives, analogs and homologues thereof.

Alkylene oxide polymers and interpolymers and their derivatives in which the terminal hydroxyl groups have been modified by esterification, etherification, etc. constitute another class of known synthetic lubricating oils. These include polyoxyalkylene polymers prepared by polymerization of ethylene oxide or propylene oxide, alkyl and aryl ethers of polyoxyalkylene polymers (eg, methyl-polyisopropylene glycol ether having a molecular weight of 1000, or polyethylene having a molecular weight of 1000 to 1500). diphenyl ether glycol); their mono- - and polycarboxylic esters, for example, the acetic acid esters, C ₁₃ oxo acid diester of mixed C ₃ -C ₈ fatty acid esters and tetraethylene glycol.
Another suitable type of synthetic lubricating oil is a dicarboxylic acid (eg, phthalic acid, succinic acid, alkyl succinic acid and alkenyl succinic acid, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid Dimers, malonic acids, alkylmalonic acids, alkenylmalonic acids) and esters of various alcohols (eg, butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol). Specific examples of such esters include dibutyl adipate, di (2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate , Dieicosyl sebacate, 2-ethylhexyl diester of linoleic acid dimer, and complex esters formed by reacting 1 mol of sebacic acid with 2 mol of tetraethylene glycol and 2 mol of 2-ethylhexanoic acid.

Esters useful as synthetic oils include those made from C ₅ -C ₁₂ monocarboxylic acids and polyols and polyol esters such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol and tripentaerythritol. included.
Silicon-based oils, such as polyalkyl-, polyaryl-, polyalkoxy-, or polyaryloxysilicone oils, and silicate oils include another useful class of synthetic lubricants; , Tetraethyl silicate, tetraisopropyl silicate, tetra- (2-ethylhexyl) silicate, tetra- (4-methyl-2-ethylhexyl) silicate, tetra- (p-tert-butyl-phenyl) silicate, hexa- (4-methyl- 2-ethylhexyl) disiloxane, poly (methyl) siloxane, and poly (methylphenyl) siloxane are included. Other synthetic lubricating oils include liquid esters of phosphorus-containing acids (eg, tricresyl phosphate, trioctyl phosphate, diethyl ester of decyl phosphate), and polymeric tetrahydrofuran.
Unrefined, refined, and rerefined oils can be used in the lubricants of the present invention. Unrefined oils are those obtained directly from natural or synthetic sources without further purification. For example, shale oil obtained directly from retorting operations; petroleum oil obtained directly from distillation; or ester oil obtained directly from esterification and used without further processing is an unrefined oil.
(Marine diesel cylinder lubricant (MDCL))
MDCL may use 10-35, preferably 13-30, most preferably 16-24% by weight of the concentrate or additive package, with the remainder being base stock. The MDCL preferably comprises at least 50, more preferably at least 60, and even more preferably at least 70% by weight of oil of lubricating viscosity relative to the total mass of MDCL. Preferably, the MDCL has a composition TBM (using ASTM D2896) of 40-100, such as 50-60.
The following can be cited as an example of typical proportions of additives in MDCL.

(Trunk piston engine oil) ("TPEO")
TPEO may use 7-35, preferably 10-28, more preferably 12-24% by weight of the concentrate or additive package, with the remainder being base stock. Preferably, the TPEO has a composition TBN (using D2896) of 25-60, such as 25-55.
The following can be mentioned as an example of typical proportions of additives in TPEO.

  If multiple additives are used, it may be desirable to prepare one or more additive packages that contain the additives, although not necessarily, in which case several additives are added to the base oil at the same time. Thus, a lubricating oil composition can be formed. The dissolution of the additive package in the lubricating oil can be facilitated by a solvent and by mixing with gentle heating, but this is not necessary. The additive package typically contains the additive in the proper amount to obtain the desired concentration and / or the final package when the additive package is combined with a predetermined amount of base lubricant. So as to perform the intended function in a typical formulation. Thus, the compounds according to the invention can be mixed with small amounts of base oils or other compatible solvents together with other desired additives so that an additive package containing the active ingredient is formed.

A more detailed description of the additive components is given below.
(Cleaning agent)
Detergents are additives that reduce the formation of deposits in the engine, such as high temperature varnish and lacquer deposits; have acid neutralization properties and can keep finely divided solids in suspension is there. It is based on metal “soaps”, ie metal salts of acidic organic compounds, sometimes called surfactants.
The detergent includes a polar head with a long hydrophobic tail. Large amounts of metal bases are included by reacting excess metal compounds such as oxides or hydroxides with acidic gases such as carbon dioxide, resulting in neutralization as the outer layer of metal base (eg, carbonate) micelles. An overbased detergent is obtained which contains the treated detergent.
The detergent is preferably an alkali such as an overbased oil-soluble or oil-dispersible calcium, magnesium, sodium, or barium salt of a surfactant selected from phenol, sulfonic acid, carboxylic acid, salicylic acid, and naphthenic acid. Metal or alkaline earth metal additives, this overbasing is stabilized by oil-soluble salts of surfactants, oil-insoluble metal salts such as carbonates, basic carbonates, acetates, formates , Hydroxide, or oxalate. The metal of the salt of the oil-soluble surfactant may be the same as or different from the metal of the oil-insoluble salt. Preferably, the metal is calcium, whether an oil-soluble salt metal or an oil-insoluble salt metal.

The detergent TBN as determined by ASTM D2896 may be low, i.e. less than 50 mg KOH / g, moderate, i.e. 50-150 mg KOH / g, or high, i.e. It may exceed 150 mg KOH / g. Preferably, the TBN is moderate or high, i.e. higher than 50 TBN. More preferably, the TBN determined by ASTM D2896 is at least 60, more preferably at least 100, more preferably at least 150, and up to 500, such as up to 350 mg KOH / g.
(Antioxidant)
The trunk piston diesel engine lubricant composition may include at least one antioxidant. The antioxidant may be amine-based or phenol-based. Examples of amines include secondary aromatic amines such as diarylamines, such as diphenylamine where each phenyl group is alkyl substituted with an alkyl group having 4 to 9 carbon atoms. Examples of antioxidants include hindered phenols including monophenols and bisphenols.
Preferably, the antioxidant, if present, is provided in the composition in an amount up to 3% by weight relative to the total amount of the lubricant composition.
Other additives such as pour point depressants, antifoams, metal rust inhibitors, pour point depressants, and / or demulsifiers may be provided as needed.

As used herein, the term “oil-soluble” or “oil-dispersible” means that the compound or additive is soluble, soluble, miscible or suspended in the oil in all proportions. It does not necessarily indicate that turbidity is possible. However, these terms mean, for example, that they are soluble or can be stably dispersed in the oil to the extent that they are sufficient to have the intended effect in the environment in which the oil is used. Furthermore, the additional incorporation of other additives also allows the incorporation of higher levels of specific additives as needed.
The lubricant composition of the present invention includes defined individual (ie, individual) components that may or may not remain chemically the same before and after mixing.
Preparing one or more additive packages or concentrates containing additives that can be added simultaneously to an oil of lubricating viscosity to form a lubricating oil composition; Although considered desirable, it is not necessary. The dissolution of the additive package in the lubricating oil can be facilitated by a solvent and by mixing with gentle heating, but this is not necessary. The additive package typically contains the additive in the proper amount to obtain the desired concentration and / or the final package when the additive package is combined with a predetermined amount of base lubricant. So as to perform the intended function in a typical formulation.
Thus, the active ingredient is contained in a proportion suitable for the additive package, for example 2.5 to 90, preferably 5 to 75, most preferably 8 to 60% by weight of additive, the rest being base oil. A small amount of base oil or other compatible solvent can be mixed with other desired additives so that an additive package is formed.
The final formulation typically contains about 5-40% by weight of the additive package, with the remainder being base oil.

(Viscosity modifier)
In the present invention, as described above, the viscosity modifier (B) is further provided.
The present invention uses a polymer that includes a core and a plurality of polymer arms extending from the core. Such polymers are known as star-shaped polymers (or star-shaped or radial polymers). Examples of the range of (B) in the composition include 0.1 to 6, 0.1 to 5, 0.1 to 4, 0.1 to 3% by mass, and 1% by mass of the lower limit.
The viscosity modifier comprises a polymer derivable from the polymerization of one or more conjugated diene monomers, at least partially hydrogenated, at least partially defined above, in the form of at least one star. May be. Suitably, the star-shaped polymer comprises a number of arms extending from the central core; this arm is derived from the polymerization of one or more conjugated diene monomers as defined above, which is defined above. Polymerization of vinyl aromatic hydrocarbon monomers may also be used.

The star polymer arm may be a homopolymer essentially derived from the polymerization of a single conjugated diene monomer as defined herein, particularly isoprene, such as isoprene or 1,3-butadiene. .
Alternatively, the star polymer arms are copolymers derived essentially from the polymerization of two or more conjugated diene monomers as defined herein, such as isoprene and 1,3-butadiene copolymers, or isoprene-styrene copolymers, Essential from the polymerization of one or more conjugated diene monomers as defined herein and a vinyl aromatic hydrocarbon monomer as defined herein, such as a butadiene-styrene copolymer or an isoprene-butadiene-styrene copolymer. It may also be a copolymer derived from

As used herein in connection with a polymer composition, “essentially derived” is recognized to include other materials that do not materially affect the characteristics of the polymer to which it is applied. Preferably, “essentially derived” means that the specified monomers and comonomers are in an amount of at least 90%, more preferably 95%, even more preferably more than 99% by weight of the polymer in the case of copolymers. Means it exists.
The arms of the star polymer are block copolymers, preferably linear block copolymers, more preferably linear diblock copolymers, such as the general formula:
A _z − (B−A) _y −B _x
(Where:
A is a polymer block derived primarily from vinyl aromatic hydrocarbon monomers;
B is a polymer block derived primarily from conjugated diene monomers;
x and z are independently numbers equal to 0 or 1;
y is an integer ranging from 1 to about 15. )
It may be represented by.

Star polymer arms are tapered linear block copolymers, such as the following general formula: AA / B-B
(Where:
A is a polymer block derived primarily from vinyl aromatic hydrocarbon monomers;
B is a polymer block derived primarily from conjugated diene monomers;
A / B is a tapered segment derived from both vinyl aromatic hydrocarbon monomers and conjugated diolefin monomers. )
It may be represented by.
Preferably, the star polymer arm comprises a hydrogenated isoprene-butadiene copolymer, a hydrogenated styrene-isoprene-butadiene copolymer, a hydrogenated isoprene-styrene copolymer, or a hydrogenated butadiene-styrene copolymer.
Most preferably, the star polymer arm comprises a linear diblock copolymer as defined herein. Preferably, the linear diblock copolymer comprises at least one block predominantly derivable from a vinyl aromatic hydrocarbon monomer as defined herein and one or more conjugated diene monomers as defined herein. At least one block that is mainly derivable from. Preferably, the vinyl aromatic hydrocarbon monomer comprises styrene. Preferably, the one or more conjugated diene monomers include isoprene, butadiene, or mixtures thereof. Most preferably, the linear diblock copolymer is at least partially hydrogenated.

Preferably, at least one block predominantly derivable from a vinyl aromatic hydrocarbon monomer (eg, styrene) in the linear diblock copolymer is at most 35% by weight relative to the total weight of the linear diblock copolymer, More preferably it is present in an amount of up to 25% by weight, most preferably 5-25% by weight.
Preferably, at least one block predominantly derivable from one or more conjugated diene monomers is greater than 65% by weight, even more preferably 75% by weight or more, most preferably based on the total weight of the linear diblock copolymer Is present in an amount of 75-95% by weight.
Preferably, the linear diblock copolymer comprises at least one polystyrene block and blocks derived from isoprene, butadiene, or mixtures thereof. Highly preferred linear diblock copolymers are at least one linear diblock selected from hydrogenated styrene / isoprene diblock copolymers, hydrogenated styrene / butadiene diblock copolymers, and hydrogenated styrene / isoprene-butadiene diblock copolymers. Includes linear diblock copolymers, including block copolymers.
Preferably, when the linear diblock copolymer comprises at least one isoprene-butadiene block, this block is derived primarily from 70-90% by weight isoprene monomer and 30-10% by weight 1,3-butadiene monomer. The

The star polymer arm typically comprises a copolymer derived from 70-90% by weight of isoprene monomer and 30-10% by weight of 1,3-butadiene monomer. More preferably, the star polymer arm further comprises a vinyl aromatic hydrocarbon monomer as defined herein, in particular styrene. Highly preferred copolymers are derived from isoprene monomers, 1,3-butadiene monomers, and vinyl aromatic hydrocarbon monomers, particularly styrene. The vinyl aromatic hydrocarbon monomer may be present in an amount up to 35% by weight, preferably up to 25% by weight, based on the total weight of the copolymer.
Preferably, the star polymer arms are formed via anionic polymerization to form a living polymer. Anionic polymerization has been found to provide copolymers having a narrow molecular weight distribution (Mw / Mn), such as a molecular weight distribution of less than about 1.2.
As is well known and disclosed, for example, in U.S. Pat. No. 4,116,917, living polymers are prepared from conjugated diene monomers in the presence of alkali metals or alkali metal hydrocarbons such as sodium naphthalene as anionic initiators. It can be prepared by anionic solution polymerization of the mixture. Preferred initiators are lithium or monolithium hydrocarbons. Suitable lithium hydrocarbons include unsaturated compounds such as allyl lithium, methallyl lithium; aromatic compounds such as phenyl lithium, tolyl lithium, xylyl lithium, and naphthyl lithium, particularly methyl lithium, ethyl lithium, propyl lithium, butyl Alkyllithiums such as lithium, amyllithium, hexyllithium, 2-ethylhexyllithium, and n-hexadecyllithium are included. Secondary butyl lithium is a preferred initiator. The initiator may be combined with additional monomers but can be added to the polymerization mixture in two or more stages. Living polymers are olefinically unsaturated.

Solvents from which the living polymer is formed are hydrocarbons such as aliphatic hydrocarbons such as pentane, hexane, heptane, octane, 2-ethylhexane, nonane, decane, cyclohexane, methylcyclohexane, or aromatic hydrocarbons such as benzene. Inert liquid solvent such as toluene, ethylbenzene, xylene, diethylbenzene, propylbenzene. Cyclohexane is preferred. Mixtures of hydrocarbons such as lubricating oils may be used.
The temperature at which the polymerization is carried out may vary within a wide range, such as from about −50 ° C. to about 150 ° C., preferably from about 20 ° C. to about 80 ° C. The reaction is suitably carried out in an inert atmosphere such as nitrogen and may be carried out under pressure, for example under a pressure of about 0.5 to about 10 bar.
The concentration of initiator used to prepare the living polymer can vary within wide limits and is determined by the desired molecular weight of the living polymer.

  To form a star polymer, the living polymer formed via the process described above is reacted with a polyalkenyl coupling agent in an additional reaction step. Polyalkenyl coupling agents capable of forming star polymers have been known for many years and are described, for example, in US Pat. No. 3,985,830. Polyalkenyl coupling agents are conventional compounds having at least two non-conjugated alkenyl groups. Such groups are usually attached to the same or different electron withdrawing moieties, such as aromatic nuclei. Such a compound has the property that it can react independently with a living polymer having at least different alkenyl groups, and is different from conventional conjugated diene polymerizable monomers such as butadiene and isoprene in this respect. Pure or industrial polyalkenyl coupling agents may be used. Such compounds may be aliphatic, aromatic, or heterocyclic. Examples of aliphatic compounds include polyvinyl and polyallyl acetylene, diacetylene, phosphate, and phosphate, and dimethacrylates such as ethylene dimethyl acrylate. Examples of suitable heterocyclic compounds include divinyl pyridine and divinyl thiophene.

Preferred coupling agents are polyalkenyl aromatic compounds, most preferably polyvinyl aromatic compounds. Examples of such compounds are aromatic compounds such as, for example, benzene, toluene, xylene, anthracene, naphthalene, and durene, preferably substituted with at least two alkenyl groups bonded directly thereto. Compounds are included. Specific examples include polyvinylbenzene, such as divinyl, trivinyl, and tetravinylbenzene; divinyl, trivinyl, and tetravinylortho-, meta-, and para-xylene, divinylnaphthalene, divinylethylbenzene, divinylbiphenyl, diisobutenylbenzene, Diisopropenylbenzene and diisopropenylbiphenyl are included. Preferred aromatic compounds are those represented by the formula A— (CH═CH ₂ ) _x , where A is an optionally substituted aromatic nucleus and x is an integer of at least 2. is there. Divinylbenzene, especially meta-divinylbenzene, is the most preferred aromatic compound. Pure or industrial divinylbenzene (containing other monomers such as styrene and ethylstyrene) may be used. The coupling agent may be used in a mixture with a small amount of added monomer that increases the size of the core, eg styrene or alkylstyrene. In such cases, the nucleus can be described as a poly (dialkenyl coupling agent / monoalkenyl aromatic compound) nucleus, such as a poly (divinylbenzene / monoalkenyl aromatic compound) nucleus.

The polyalkenyl coupling agent should be added to the living polymer after the monomer polymerization is substantially complete, i.e., the agent is added only after substantially all of the monomer has been converted to the living polymer. Should be.
The amount of polyalkenyl coupling agent added may vary within wide limits, but preferably at least 0.5 mole of coupling agent is used per mole of unsaturated living polymer. An amount of about 1 to about 15 moles, preferably about 1.5 to about 5 moles per mole of living polymer is preferred. The amount that can be added in two or more stages is usually an amount sufficient to convert at least about 80% to 85% by weight of the living polymer to a star-shaped polymer.
The coupling reaction can be carried out in the same solvent as the living polymerization reaction. The coupling reaction can be carried out at a temperature within a wide range such as 0 ° C. to 150 ° C., preferably about 20 ° C. to about 120 ° C. The reaction may be carried out in an inert atmosphere, such as nitrogen, under a pressure of about 0.5 bar to about 10 bar.
The star polymer thus formed comprises a dense center or core of cross-linked poly (polyalkenyl coupling agent) and several arms of a substantially linear unsaturated polymer extending outwardly from the core. Is characterized by The number of arms may vary greatly, but is typically between about 4-25.

The resulting star polymer can then be hydrogenated using any suitable means. Hydrogenation catalysts such as copper or molybdenum compounds may be used. A catalyst containing a noble metal or a noble metal-containing compound can also be used. Preferred hydrogenation catalysts contain non-noble metals of group VIII of the periodic table, ie iron, cobalt, in particular nickel, or these non-noble metal-containing compounds. Specific examples of preferred hydrogenation catalysts include Raney nickel and nickel supported on diatomaceous earth. A particularly suitable hydrogenation catalyst is obtained by reacting a metal hydrocarbyl compound with an organic compound of any one of the Group VIII metals iron, cobalt, or nickel, the latter compound being, for example, As described in British Patent No. 1,030,306, it contains at least one organic compound bonded to a metal atom through an oxygen atom. Aluminum trialkyl (eg, aluminum diethyl (Al (Et ₃ )) or aluminum triisobutyl) is replaced with a nickel salt of an organic acid (eg, nickel diisopropyl salicylate, nickel naphthenate, nickel 2-ethylhexanoate, nickel di- tert-butylbenzoate, a nickel salt of a saturated monocarboxylic acid obtained by the reaction of an olefin having 4 to 20 carbon atoms in the molecule with carbon monoxide and water in the presence of an acid catalyst) or nickel enolate or phenol Hydrogenation catalysts obtained by reacting with a rate (eg nickel acetonyl acetonate, nickel salt of butyl acetophenone) are preferred. Suitable hydrogenation catalysts are well known to those skilled in the art, and the foregoing list is by no means exhaustive.

The hydrogenation of the star polymer is suitably carried out by dissolving it in an inert solvent during the hydrogenation reaction. Saturated hydrocarbons and mixtures of saturated hydrocarbons are suitable. Advantageously, the hydrogenation solvent is the same as the solvent in which the polymerization is carried out. Suitably, at least 50%, preferably at least 70%, more preferably at least 90%, and most preferably at least 95% by weight of the initial olefinic unsaturation is hydrogenated.
The hydrogenated star polymer can then be recovered in solid form from the solvent and hydrogenated by any conventional means, such as by evaporation of the solvent. Alternatively, an oil, such as a lubricating oil, may be added to the solution and the solvent is removed from the so-formed mixture to provide a concentrate. Suitable concentrates contain from about 3% to about 25%, preferably from about 5% to about 15%, by weight of hydrogenated star polymer VI improver.

Star polymers useful in the practice of the present invention can have a number average molecular weight of about 10,000 to 700,000, preferably about 30,000 to 500,000. The term “number average molecular weight” as used herein refers to the number average mass, as determined by gel permeation chromatography (“GPC”) using polystyrene standards after hydrogenation. When using this method to determine the number average molecular weight of the star polymer, it is important to note that the calculated number average molecular weight is less than the actual molecular weight due to the three-dimensional structure of the star polymer.
In one preferred embodiment, the star polymer of the present invention is derived from about 75% to about 90% by weight isoprene and from about 10% to about 25% by weight butadiene, with 80% by weight of butadiene units. Super is an incorporated 1,4-addition product. In another preferred embodiment, the star polymer of the present invention is derived from 1,2-incorporation of about 30 to about 80% by weight butadiene and 1,4-incorporation of about 20 to about 70% by weight butadiene. In addition, it contains amorphous butadiene units. In another preferred embodiment, the star polymer is derived from isoprene, butadiene, or mixtures thereof and further contains from about 5 to about 35 weight percent styrene units.
Typically, star polymers have a shear stability index (SSI) of about 1% to 35% (30 cycles). Examples of commercially available star polymer VI improvers having an SSI of 35 or less are from Infineum USA L. P. And Infineum UK Ltd. Infineum SV200 ™ available from Other examples of commercially available star polymer VI improvers having an SSI of 35 or less also include Infineum USA L. P. And Infineum UK Ltd. Infineum SV250 ™, Infineum SV261 ™, and Infineum SV270 ™ available from
Typically, the viscosity modifier may be provided in an amount of 0.01-20, preferably 1-15% by weight, based on the weight of the lubricating oil composition.

One or both types of viscosity modifiers used in the practice of the present invention may be provided with nitrogen-containing functional groups that impart a dispersing ability to the VI improver. One trend in the industry has been to use such “multifunctional” VI improvers in lubricants so that some or all of the dispersant is replaced. Nitrogen-containing functional groups can be added to the polymer VI improver by grafting a nitrogen or hydroxyl-containing moiety, preferably a nitrogen-containing moiety, onto the polymer backbone of the VI improver (functionalization). Processes for grafting nitrogen-containing moieties onto polymers are known in the art, for example, polymer and nitrogen-containing moieties remain untreated in the presence of a free radical initiator or in the presence of a solvent. Including contact with. Free radical initiators may be generated by shearing (like an extruder) or heating a free radical initiator precursor such as hydrogen peroxide.
The amount of nitrogen-containing grafted monomer will depend to some extent on the nature of the base polymer and the level of dispersibility required for the grafted polymer. To impart dispersibility characteristics to both star and linear copolymers, the amount of grafted nitrogen-containing monomer is suitably about 0.4 to about 2.2 weight based on the total weight of the grafted polymer. %, Preferably from about 0.5 to about 1.8% by weight, most preferably from about 0.6 to about 1.2% by weight.

  Methods for grafting nitrogen-containing monomers onto the polymer backbone and suitable nitrogen-containing graft monomers are known, such as US Pat. No. 5,141,996, WO 98/13443, WO 99/21902, U.S. Pat. No. 4,146,489, U.S. Pat. No. 4,292,414, and U.S. Pat. No. 4,506,056. J Polymer Science, Part A: Polymer Chemistry, Vol. 26, 1189-1198 (1988); Polymer Science, Polymer Letters, Vol. 20, 481-486 (1982); Polymer Science, Polymer Letters, Vol. 21, 23-30 (1983), all by Gaylord and Mehta, and Degradation and Cross-linking of Ethylene-Propylene Polymer Rubber with Reaction with Male Ped./Hydride. Applied Polymer Science, Vol. 33, 2549-2558 (1987) (by Gaylord, Mehta, and Mehta).

The present invention is illustrated by the following examples, which are not intended to limit the invention in any way.
(MDCL)
A set of MDCL was formulated, each containing 20.89% by weight of the same proportion of additive and having a TBN of about 70. The set included a control consisting of additive and base oil; a reference consisting of additive, base oil and bright stock; and an MDCL of the present invention consisting of additive, base oil and viscosity modifier. . The additive was an additive known in the art and used in proportions known in the art to provide MDCL properties. The viscosity modifier was a star polymer in the form of an amorphous styrene-diene copolymer. The bright stock was a Group I bright stock with a kinematic viscosity of> 20 cSt at 100 ° C. The base oil was a Group 1 base oil.
(TPEO)
A set of TPEO was formulated, each containing 16% by weight of the same additive in the same proportion and having a TBN of about 40. The set included a control consisting of additive and base oil; a reference consisting of additive, base oil, and bright stock; and a TPEO of the present invention consisting of additive, base oil, and viscosity modifier. . The additive was an additive known in the art and used in proportions known in the art to provide TPEO properties. Viscosity modifiers, bright stock, and base oil were as used in MDCL.

(Test and results)
A sample of the above formulation is subject to the following conditions:
・ 120min ・ 20mm reciprocating motion with 1mm stroke length ・ PCS Instruments high frequency reciprocating rig (200g load using standard steel manufacturer supplied steel base) HFRR).

Each test was repeated two more times and the recorded wear measurements were the average of these values.
The HFRR data for the composition is summarized in the following table.

  The above results show that amorphous styrene-diene isoprene star polymer advantageously reduces wear scar volume for TPEO oil compared to control and reference. In the case of MDCL, it is clearly advantageous to include a star polymer over the case where no bright stock is used.

The above results show that amorphous styrene-diene isoprene star polymer advantageously reduces wear scar volume for TPEO oil compared to control and reference. In the case of MDCL, it is clearly advantageous to include a star polymer over the case where no bright stock is used.
Another aspect of the present invention may be as follows.
[1] a large amount of oil of lubricating viscosity;
(A) a small amount of each additive;
(B) a viscosity modifier in the form of a polymer comprising a core and a plurality of polymer arms extending therefrom in an amount ranging from 0.05 to 6% by weight;
A two-stroke or four-stroke marine engine lubricating oil composition comprising:
Bright stock is included in less than 0.5% by weight, preferably less than 0.1% by weight; preferably bright stock is completely or substantially absent from the composition; the two-stroke marine engine lubricating oil composition Has a TBN of 40-100 using ASTM D2896, or the 4-stroke marine engine lubricant composition has a TBN of 25-60 using ASTM D2896
Composition.
[2] The composition according to [1], wherein the polymer arm comprises a hydrogenated isoprene-butadiene copolymer, a hydrogenated styrene-isoprene-butadiene copolymer, a hydrogenated isoprene-styrene copolymer, or a hydrogenated butadiene-styrene copolymer. object.
[3] The composition according to [1] or [2] above, wherein the polymer arm includes a linear diblock copolymer.
[4] The composition according to any one of [1] to [3], wherein the polymer has a number average molecular weight of 10,000 to 700,000, for example, 30,000 to 500,000.
[5] The composition according to any one of [1] to [4], in the form of a marine diesel cylinder lubricant.
[6] The composition according to any one of [1] to [4], in the form of a trunk piston engine oil.
[7] From the above [1] to [4] for improving wear resistance of marine diesel cylinder lubricant or trunk piston engine oil containing bright stock less than 0.5% by mass, preferably less than 0.1% by mass ] The use of the viscosity modifier (B) of any one of the preceding claims, wherein the two-stroke marine engine lubricating oil composition has a TBN of 40-100 using ASTM D2896, or 4 Use, wherein the stroke marine engine lubricating oil composition has a TBN of 25-60 using ASTM D2896.
[8] The use according to [7], wherein the marine diesel cylinder lubricant or the trunk piston engine oil does not substantially contain bright stock.
[9] The marine diesel cylinder lubricant or the trunk piston engine oil such that the marine diesel cylinder lubricant or the trunk piston engine oil contains less than 0.5% by mass of bright stock, preferably less than 0.1% by mass. Use of the viscosity modifier (B) according to any one of [1] to [4] as a substitute for part or all of the bright stock in
[10] A method for lubricating a crosshead marine diesel engine, comprising supplying the composition according to any one of [1] to [5] to an engine piston / cylinder assembly.
[11] A method of lubricating a trunk piston marine diesel engine, comprising supplying the engine according to any one of [1] to [4] or 6 above.
[12] A method for reducing the amount of bright stock in a 2-stroke or 4-stroke marine engine lubricating oil composition comprising a large amount of oil of lubricating viscosity and (A) a small amount of each additive, Replacing part or all of the bright stock with a viscosity modifier in the form of a polymer comprising (B) a core and a plurality of polymer arms extending therefrom, in an amount ranging from 0.05 to 6% by weight.
[13] such that the composition contains less than 0.5 wt% bright stock, preferably less than 0.1 wt%; preferably such that the composition is completely or substantially free of bright stock, The method according to [12], wherein (B) substantially substitutes for the bright stock.
[14] The composition contains less than 0.5% by weight of bright stock, preferably less than 0.1% by weight; preferably, the composition is completely or substantially free of bright stock, [12] Or the method of [13].
[15] The 2-stroke marine engine lubricating oil composition has a TBN of 40-100 using ASTM D2896, or the 4-stroke marine engine lubricating oil composition is 25 using ASTM D2896. The method according to any one of [12], [13], or [14] above, having a TBN of ˜60.

Claims (15)

A lot of oil of lubricating viscosity,
(A) a small amount of each additive;
(B) a two-stroke or four-stroke marine engine lubricant composition comprising a core and a viscosity modifier in the form of a polymer comprising a plurality of polymer arms extending therefrom in an amount ranging from 0.05 to 6% by weight. A thing;
Bright stock is included in less than 0.5% by weight, preferably less than 0.1% by weight; preferably bright stock is completely or substantially absent from the composition; the two-stroke marine engine lubricating oil composition Has a TBN of 40-100 using ASTM D2896, or the 4-stroke marine engine lubricating oil composition has a TBN of 25-60 using ASTM D2896.   The composition of claim 1, wherein the polymer arm comprises a hydrogenated isoprene-butadiene copolymer, a hydrogenated styrene-isoprene-butadiene copolymer, a hydrogenated isoprene-styrene copolymer, or a hydrogenated butadiene-styrene copolymer.   The composition of claim 1 or claim 2, wherein the polymer arm comprises a linear diblock copolymer.   4. A composition according to any one of claims 1 to 3, wherein the polymer has a number average molecular weight of 10,000 to 700,000, for example 30,000 to 500,000.   A composition according to any one of claims 1 to 4 in the form of a marine diesel cylinder lubricant.   5. A composition according to any one of claims 1 to 4 in the form of a trunk piston engine oil.   Any one of claims 1 to 4 for improving the wear resistance of marine diesel cylinder lubricants or trunk piston engine oils containing less than 0.5% by weight of bright stock, preferably less than 0.1% by weight. The use of the viscosity modifier (B) according to claim 2, wherein the two-stroke marine engine lubricating oil composition has a TBN of 40 to 100 using ASTM D2896, or a four-stroke marine engine lubricating oil. Use, wherein the composition has a TBN of 25-60 using ASTM D2896.   8. Use according to claim 7, wherein the marine diesel cylinder lubricant or the trunk piston engine oil is substantially free of bright stock.   In the marine diesel cylinder lubricant or trunk piston engine oil, such that the marine diesel cylinder lubricant or trunk piston engine oil contains less than 0.5 wt% bright stock, preferably less than 0.1 wt%. Use of the viscosity modifier (B) according to any one of claims 1 to 4 as a part or all substitute for bright stock.   A method of lubricating a crosshead marine diesel engine comprising supplying the composition of any of claims 1-5 to an engine piston / cylinder assembly.   A method of lubricating a trunk piston marine diesel engine comprising supplying the composition of any of claims 1 to 4 or 6 to the engine.   A method for reducing the amount of bright stock in a two-stroke or four-stroke marine engine lubricating oil composition comprising a large amount of oil of lubricating viscosity and (A) a small amount of each additive, comprising: Replacing part or all with (B) a viscosity modifier in the form of a polymer comprising a core and a plurality of polymer arms extending therefrom in an amount ranging from 0.05 to 6% by weight.   (B) such that the composition contains less than 0.5% by weight of bright stock, preferably less than 0.1% by weight; preferably the composition is completely or substantially free of bright stock. 13. The method of claim 12, wherein substantially substitutes for the bright stock.   14. The composition according to claim 12 or 13, wherein the composition comprises less than 0.5% by weight of bright stock, preferably less than 0.1% by weight; preferably the composition is completely or substantially free of bright stock. the method of.   The 2-stroke marine engine lubricating oil composition has a TBN of 40-100 using ASTM D2896, or the 4-stroke marine engine lubricating oil composition is 25-60 using ASTM D2896. 15. A method according to any one of claims 12, 13, or 14 having TBN.