JP6907249B2 - Lubrication of marine engines - Google Patents

Description

The present invention relates to lubrication of a two-stroke and four-stroke marine diesel internal combustion engine, the former being commonly referred to as a crosshead engine and the latter being referred to as a trunk piston engine. Each lubricant for that purpose is commonly known as marine diesel cylinder lubricant (“MDCL”) and trunk piston engine oil (“TPEO”).

A crosshead engine is a low speed engine that ranges from high power to extremely high power. These are lubricated by two separately lubricated parts: a piston / cylinder assembly lubricated by total loss lubrication with a highly viscous oil (MDCL), and a less viscous lubricant commonly referred to as system oil. Includes crankshaft.
Trunk piston engines can be used in marine, generator and railroad motor vehicle applications and have faster speeds than crosshead engines. A single lubricant (TPEO) is used to lubricate the crankcase and cylinder. All major moving parts of the engine, namely the major large end bearings, camshafts and valve gears, are lubricated by the pumped circulation system. The cylinder liner is partially lubricated by splash lubrication and partially by oil from the circulatory system, which reaches the cylinder wall through holes in the piston skirt via connecting rods and gudgeon pins.

In the art, MDCL and TPEO are known to include bright stock, which is a highly viscous oil, which is highly refined and dewaxed, from residual stock or bottom. Manufactured. For example, it can have a kinematic viscosity at 100 ° C ^{above 25 mm 2} / sec, usually above 30 mm ² / sec, eg a decompression having a kinematic viscosity at 100 ° C in the range of ^{28-36 mm 2 / sec.} It can be a solvent-extracted, de-asphalated product derived from residual oil.

However, bright stock is expensive and the art describes ways to replace it. WO 99/64543 describes MDCL formulated without Brightstock, and US 2008/0287329 describes TPEO with little or no Brightstock. Both of these use liquid, oil-miscible polyisobutylene (PIB).
One problem with MDCL and TPEO without brightstock is that they cause the drawback of evaporation (ie, evaporation and consumption of lubricating oil). As discussed in US 2008/0287329, the degradation of polyisobutylene results in the formation of volatile products, which escape from the engine, resulting in the consumption of lubricating oil.

An object of the present invention is to overcome problems of the prior art. In particular, one of the objects of the present invention is to reduce the consumption of lubricating oil.

Here, the use of star-shaped polymers (eg, amorphous styrene-diene copolymers) or olefin-based copolymers (eg, ethylene-propylene copolymers) dispersed in heavy diluent oils in MDCL or TPEO overcomes the above problems. It was found to be possible.
That is, the present invention is a two-stroke or four-stroke marine engine lubricating oil composition, which contains a large amount of oil having a lubricating viscosity, and has the following components:
(A) Each small amount of one or more additives; and
A viscosity modifier in the form of either (B) (i) a core and a polymer containing multiple polymer arms extending from the core, or (ii) an olefin copolymer ^{, preferably 6-15 mm 2} / sec. Is blended with a viscosity modifier dispersed in a heavy diluent oil having a kinematic viscosity at 100 ° C in the range of 7-14 mm ^{2 / sec.}
Here, the two-stroke marine engine lubricating oil composition has a TBN in the range of 10 to 100, for example, 40 to 100, as measured using ASTM D2896, and the four-stroke marine engine lubricating oil composition has. Provided are a two-stroke or four-stroke marine engine lubricating oil composition, characterized by having a TBN in the range of 25-60, measured using an ASTM D2896.

In a further aspect, the invention includes those listed below.
A method for manufacturing a two-stroke or four-stroke marine engine lubricating oil composition.
A large amount of oil with lubricating viscosity and the following components:
(A) Each small amount of one or more additives; and
A viscosity modifier in the form of either (B) (i) a core and a polymer containing multiple polymer arms extending from the core, or (ii) an olefin copolymer, such as ^{6-15 mm 2 / sec.} Including the step of blending with a viscosity modifier dispersed in a heavy diluent oil having a kinematic viscosity at 100 ° C. in the range of 7 to 14 mm ^{2 / sec.}
Here, the two-stroke marine engine lubricating oil composition has a TBN in the range of 10 to 100, for example, 40 to 100, as measured using ASTM D2896, and the four-stroke marine engine lubricating oil composition has. , A method of manufacture characterized by having a TBN in the range of 25-60, as measured using ASTM D2896.

A two-stroke or four-stroke marine engine lubricating oil composition obtained by the above method of the present invention.
A method for lubricating a crosshead marine diesel engine, which comprises a step of supplying the composition of the present invention to a piston / cylinder assembly of a crosshead marine diesel engine.
A method for lubricating a diesel engine for a trunk piston ship, which comprises a step of supplying the composition of the present invention to a diesel engine for a trunk piston ship.
And the carbon deposition properties of marine diesel cylinder lubricants with TBNs in the range 10-100, eg 40-100, measured using ASTM D2896, or 25-60 measured using ASTM D2896. Use of the viscosity modifier (B) as defined in the first aspect of the invention to improve the carbon deposition properties of trunk piston engine oils with a range of TBN.

As used herein, the following terms and expressions have the meanings described below.
"Active ingredient" or "(ai)" refers to an additive material that is not a diluent or solvent.
The term "contains" or any similar term identifies the presence of the stated feature, stage, or integer or component, but the presence or presence of one or more other features, steps, integers, components or groups thereof. Without excluding the addition, the expression "consisting of" or "consisting essentially of" or the same kind of expression may be included in the expression "contains" or of the same kind, where "consisting of essentially" is Allows the inclusion of substances that do not substantially affect the characteristics of the composition to which it is applied.

"Large amount" means 40% by mass or 50% by mass or more, preferably 60% by mass or more, and more preferably 70% by mass or more of the composition.
"Small amount" means less than 50% by weight, preferably less than 40% by weight, more preferably less than 30% by weight of the composition.
"TBN" means total base value as measured by ASTM D2896.

Further herein, when used,
"Calcium content" is as measured by ASTM 4951.
"Phosphorus content" is as measured by ASTM D5185.
"Sulfate ash content" is as measured by ASTM D874.
"Sulfur content" is as measured by ASTM D2622.
"KV 100" means kinematic viscosity at 100 ° C as measured by ASTM D445.
Also, the various ingredients used are essential, as well as optimal and conventional, but may react under prescription, storage or use conditions, and the present invention is also any such reaction. It will also be appreciated that it provides the product that can or is obtained as a result of.
Further, it is understood that any upper and lower limits of quantities, ranges and proportions specified herein can be combined independently.

The features of the present invention will be discussed in more detail below.
Lubricating Viscosity Oils Lubricating compositions contain a high proportion of lubricating viscosity oils. Such lubricants can range from light fraction mineral oils to heavy lubricants. In general, the viscosity of the oil, measured at 100 ° C., 2 to 40 mm ² / sec in scope, for example, located in the 3 to 15 mm ² / sec in scope, the viscosity index is 80 to 100 range, for example 90 to 95 In range. Lubricating oils can make up more than 60% by weight, typically more than 70% by weight, of the composition.

Natural oils include animal and vegetable oils (eg, castor oil, lard oil); liquid petroleum and paraffin-type, naphthen-type and mixed paraffin-naphthen-type hydrorefined, solvent-treated or acid-treated mineral oils. Can be mentioned. Lubricating viscosity oils derived from coal or shale also serve as useful base oils.
Synthetic lubricants include hydrocarbon oils and halo-substituted hydrocarbon oils, such as polymerized and copolymerized olefins (eg, polybutylene, polypropylene, propylene-isobutylene copolymers, chlorinated polybutylene, poly (1-hexene), poly (1). -Octen), poly (1-decene)); alkylbenzene (eg, dodecylbenzene, tetradecylbenzene, dinonylbenzene, di (2-ethylhexyl) benzene); polyphenyl (eg, biphenyl, terphenyl, alkylated polyphenol) And alkylated diphenyl ethers and alkylated diphenyl sulfides, as well as derivatives, analogs and homologues thereof.

The alkylene oxide polymers and copolymers and their derivatives have their terminal hydroxyl groups modified by esterification, etherification, etc., and constitute another class of known synthetic lubricating oils. These are polyoxyalkylene polymers prepared by polymerization of ethylene oxide or propylene oxide, and alkyl and aryl ethers of polyoxyalkylene polymers (eg, methyl-polyiso-propylene glycol ethers with a molecular weight of 1000, or molecular weights of 1000-1500. Poly-ethylene glycol diphenyl ethers); and their mono- and polycarboxylic acid esters, such as tetraethylene glycol acetate, mixed C _3- C ₈ fatty acid esters and C ₁₃ oxo acid diesters.

Other suitable classes of synthetic lubricants are dicarboxylic acids (eg, phthalic acid, succinic acid, alkyl succinic acid and alkenyl succinic acid, malonic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid. It contains esters of dimer, malonic acid, alkylmalonic acid, alkenylmalonic acid) and 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, Examples include diicosyl sebacate, 2-ethylhexyl diester of linoleic acid dimer, and composite ester 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 are also made from C _{5 to} C ₁₂ monocarboxylic acids and polyols and polyol esters such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentapentaerythritol and tripentaerythritol. Can be mentioned.
Silicone-based oils such as polyalkyl-, polyaryl-, polyalkoxy-or polyaryloxysilicone oils and silicate oils constitute another useful class of synthetic lubricants, such as 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) Examples include disiloxane, poly (methyl) siloxane and poly (methylphenyl) siloxane. Other synthetic lubricants include liquid esters of phosphorus-containing acids (eg, diethyl esters of tricresyl phosphate, trioctyl phosphate, decylphosphonic acid) and polymerized tetrahydrofuran.

Unrefined oils, refined oils and re-refined oils can be used in the lubricating oils of the present invention. Unrefined oils are oils obtained directly from natural or synthetic sources without further refining. For example, a shale oil obtained directly from a retort operation; petroleum obtained directly by distillation; or an ester oil obtained directly by esterification and used without further treatment is an unrefined oil.
The American Oil Association (API) publication, Engine Oil Licensing and Certification System, Industry Services Department, 14th Edition, December 1996, Addendum 1, December 1998, The base stock is classified as follows.

a) Group I basestock contains less than 90% saturated and / or more than 0.03% sulfur and has a viscosity of greater than or equal to 80 and less than 120 as measured using the test methods specified in Table E-1. Has an index.
b) Group II basestock contains 90% or more saturated material and 0.03% or less sulfur and has a viscosity index of 80 or more and less than 120 as measured using the test methods specified in Table E-1. Have.
c) Group III basestock contains 90% or more saturated material and 0.03% or less sulfur and has a viscosity index of 120 or more as measured using the test methods specified in Table E-1.
d) The Group IV basestock is polyalphaolefin (PAO).
e) Group V basestock includes all other basestock not included in Group I, II, III or IV.
The analysis method of the base stock is shown in the table below.

The present invention preferably includes the oils having a lubricating viscosity of 90% or more saturated and 0.03% or less sulfur, such as groups II, III, IV or V. These also include hydrocarbon-derived basestocks synthesized by the Fischer-Tropsch method. In the Fischer-Tropsch method, a syngas containing carbon monoxide and hydrogen (or "syngas") is first produced and then converted to hydrocarbons using a Fischer-Tropsch catalyst. These hydrocarbons generally require further processing in order to be useful as base oils. For example, they can be hydrogen isomerized; hydrocracked and hydrogen isomerized; dewaxed; or hydrogen isomerized and dewaxed by methods known in the art. Syngas is a gas such as natural gas or other gaseous hydrocarbons, for example, by steam reforming, where the basestock can be referred to as gas-to-liquid (“GTL”) base oil. From; or if the basestock can be referred to as biomass-to-liquid (“BTL” or “BMTL”) base oil, by gasification of biomass; or the basestock is coal-to -liquid) ("CTL") Can be produced by gasification of coal, if it can be referred to as base oil.

Preferably, the oil having a lubricating viscosity in the present invention contains 50% by mass or more of the base stock. The oil may contain 60% by weight or more, for example 70, 80 or 90% by weight or more of the basestock or a mixture thereof. An oil having a lubricating viscosity can be substantially all of the basestock or a mixture thereof.

Marine Diesel Cylinder Lubricating Oil ("MDCL")
MDCL can be in a concentrate or additive package in the range of 10-35% by weight, preferably in the range of 13-30% by weight, most preferably in the range of 16-24% by weight, the rest of which is the base stock. Is. It contains an oil having a lubricating viscosity of preferably at least 50% by weight, more preferably at least 60% by weight, even more preferably at least 70% by weight, based on the total mass of MDCL. Preferably, MDCL is TBN (measured using ASTM D2896) as a composition in the range of 10-100, eg, 40-100, preferably 60-90, more preferably 70-80. Have.

The following can be shown as an example of typical proportions of additives in MDCL.

Trunk piston engine oil ("TPEO")
For TPEO, concentrates or additive packages in the range of 7-35% by weight, preferably in the range of 10-28% by weight, more preferably in the range of 12-24% by weight can be used, the rest of which is the base stock. Is. Preferably, the TPEO has a TBN (measured using ASTM D2896) as a composition in the range 25-60, eg 25-55.

The following can be shown as typical proportions of additives in TPEO.

Additive (A)
The additive components will be described in more detail below.
Cleaners Cleansers are additives that reduce the formation of deposits in the engine, such as hot varnish and lacquer deposits, which have acid neutralizing properties and are finely ground solids in suspension. Can be maintained. It is based on the metal "soap", a metal salt of acidic organic compounds, sometimes referred to as a surfactant.
The cleaning agent includes a polar head with a long hydrophobic tail. Large amounts of metal bases can be included by reacting excess metal compounds, such as oxides or hydroxides, with acid gases, such as carbon dioxide. The resulting hyperbasic detergent comprises a neutralized detergent as the outer layer of metal base (eg, carbonate) micelles.

The cleaning agent is preferably a superbasified oil-soluble or oil-dispersible calcium, magnesium of a surfactant selected from alkali metal or alkaline earth metal additives such as phenol, sulfonic acid, carboxylic acid, salicylic acid and naphthenic acid. , Sodium or barium salts, where hyperbasification is provided by oil-insoluble salts of metals such as carbonates, basic carbonates, acetates, formates, hydroxides or oxalates and is surface active. Stabilized by the oil-soluble salt of the agent. 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 it is an oil-soluble salt metal or an oil-insoluble salt metal.
The TBN of the detergent is as measured by ASTM D2896 at low values, i.e. less than 50 mgKOH / g, moderate values, i.e. in the range 50-150 mgKOH / g, or high values, i.e. above 150 mgKOH / g. It is possible. Preferably the TBN is moderate or high, i.e. above 50 TBN. More preferably, TBN is at least 60 mgKOH / g, more preferably at least 100 mgKOH / g, more preferably at least 150 mgKOH / g, and up to 500 mgKOH / g, for example up to 350 mgKOH / g, as the value measured by ASTM D2896. Is.

Antioxidants Trunk Piston Diesel Engine Lubricants Compositions may contain at least one antioxidant. The antioxidant can be amine-based or phenol-based. Examples of amines include diarylamines such as secondary aromatic amines such as diphenylamine, where each phenyl group is alkyl substituted with an alkyl group having 4-9 carbon atoms. Examples of antioxidants include hindered phenols, including mono-phenols and bis-phenols.
Preferably, the antioxidant, if present, is provided in the composition in an amount of up to 3% by weight based on the total amount of the lubricating oil composition.

Other additives such as pour point depressants, defoamers, metal rust inhibitors, pour point depressants and / or demulsifiers can be added as needed.
As used herein, the term "oil-soluble" or "oil-insoluble" does not necessarily mean that a compound or additive is soluble, soluble, miscible or suspendable in oil in any proportion. is not it. However, these mean that the compound or additive can be soluble, for example, or stably dispersed in the oil to the extent that it exerts its intended effect in the environment in which the oil is used. .. In addition, additional formulations of other additives also allow for higher levels of formulation of certain additives, if desired.
Lubricating oil compositions of the present invention contain defined individual (ie, separate) components that may or may not maintain chemical identity before and after mixing.

It may be, but not essential, desirable to prepare one or more additive packages or concentrates containing the additives, which allow the additives to be added simultaneously to the oil of lubricating viscosity to form a lubricating oil composition. Can be formed. Dissolution of the additive package in lubricating oil can be facilitated by mixing with a solvent and with gentle heating, but this is not required. The additive package typically contains the additive in an appropriate amount to give the desired concentration, and / or when the additive package is combined with a predetermined amount of base lubricant, in the final formulation. It will be prescribed to perform its intended function.

Thus, the additive, along with other desired additives, is mixed with a small amount of base oil or other compatible solvent and, based on the additive package, for example in the range of 2.5-90% by weight, preferably 5-75. An additive package can be produced in which the active ingredient of the additive is contained in an appropriate proportion in an amount in the range of mass%, most preferably in the range of 8 to 60% by mass, and the balance is the base oil.
The final formulation typically contains an additive package in the range of about 5-40% by weight, the balance of which can be the base oil.

Viscosity modifier (B)
In the present invention, as described above, the viscosity modifier (B) is further provided in the form of (i) a so-called star polymer, or (ii) an olefin copolymer. Its concentration in the composition can range, for example, from 0.01 to 40% by weight.
(i) Star-shaped polymers These are polymers that include a core and multiple polymer arms extending from the core. Such polymers are known as star polymers (or star or radial polymers). Examples of the range (B) in the composition include a range of 0.1 to 6% by weight, 0.1 to 5% by weight, 0.1 to 4% by weight, 0.1 to 3% by weight, and a lower limit of 1% by weight.

The viscosity modifier can be at least partially induced by the polymerization of one or more conjugated diene monomers as defined above, at least one star-shaped, at least partially hydrogenated polymer. Can be included. Appropriately, the star polymer comprises a number of arms extending from the central core, the arms being one or more previously defined conjugated diene monomers, and in some cases previously defined. It is derived by the polymerization of such vinyl aromatic hydrocarbon monomers.
The arm of the star polymer can be a single conjugated diene monomer as defined herein, such as isoprene, or a homopolymer essentially induced by the polymerization of 1,3-butadiene, especially isoprene.

Alternatively, the arm of the star polymer is essentially derived from the polymerization of two or more conjugated diene monomers as defined herein, such as isoprene and 1,3-butadiene copolymers, or Copolymers essentially derived by polymerization of one or more conjugated diene monomers as defined herein and vinyl aromatic hydrocarbon monomers as defined herein, such as isoprene-styrene. It can be a copolymer, a butadiene-styrene copolymer or an isoprene-butadiene-styrene copolymer.
As used herein in the context of polymer compositions, "essentially induced" means to include other substances that do not substantially affect the properties of the polymer applied. Tolerate. Preferably, "essentially derived" means that the specified monomers and comonomer in the case of the copolymer exceed at least 90% by weight, more preferably at least 95% by weight, even more preferably 99% by weight of the polymer. It means that it exists in quantity.

The arm of a star polymer can also be a block copolymer, preferably a linear block copolymer, more preferably a linear diblock copolymer, eg, one represented by the following general formula:
A _z- (BA) _y -B _x
here,
A is a polymer block derived primarily from vinyl aromatic hydrocarbon monomers and
B is a polymer block derived primarily from conjugated diene monomers.
x and z are independently equal to 0 or 1 and
y is all values in the range 1 to about 15.

The arm of the star polymer can also be a tapered linear block copolymer, eg, one represented by the following general formula:
AA / BB
here,
A is a polymer block derived primarily from vinyl aromatic hydrocarbon monomers and
B is a polymer block derived primarily from conjugated diene monomers, and
A / B is a tapered portion derived from both a vinyl aromatic hydrocarbon monomer and a conjugated diolefin monomer.

Preferably, the arm of the star polymer 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 arm of the star polymer comprises a linear diblock copolymer as defined herein. Preferably, the linear diblock copolymer is at least one block that can be derived primarily from vinyl aromatic hydrocarbon monomers as defined herein and one or more conjugated diene as defined herein. Includes at least one block that can be derived primarily from the monomer. Preferably, the vinyl aromatic hydrocarbon monomer comprises styrene. Preferably, the one or more conjugated diene monomers comprises isoprene, butadiene or a mixture thereof. Most preferably, the linear diblock copolymer is at least partially hydrogenated.

Preferably, at least one block that can be derived primarily from the vinyl aromatic hydrocarbon monomer (eg, styrene) in the linear diblock copolymer is up to 35% by weight, based on the total mass of the linear diblock copolymer. It is more preferably present in an amount in the range of up to 25% by weight, most preferably 5 to 25% by weight.
Preferably, at least one block that can be derived primarily from one or more conjugated diene monomers is greater than 65% by weight, even more preferably 75% by weight or more, most, based on the total mass of the linear diblock copolymer. It is preferably present in an amount in the range of 75 to 95% by weight.

Preferably, the linear diblock copolymer comprises at least one polystyrene block and a block derived from isoprene, butadiene or a mixture thereof. Highly preferred linear diblock copolymers are at least one linear diblock selected from hydrogenated styrene / isoprene block copolymers, hydrogenated styrene / butadiene diblock copolymers and hydrogenated styrene / isoprene-butadiene diblock copolymers. Includes linear diblock copolymers, such as copolymers.
Preferably, if the linear diblock copolymer comprises at least one isoprene-butadiene block, the block will be an isoprene monomer in the range of 70-90% by weight and a 1,3-butadiene monomer in the range of 30-10% by weight. Is mainly derived from.

Arms of stellate polymers typically contain copolymers derived from isoprene monomers in the range 70-90% by weight and 1,3-butadiene monomers in the range 30-10% by weight. More preferably, the arm of the star polymer 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, especially styrene. The vinyl aromatic hydrocarbon monomer can be present in an amount of up to 35% by weight, preferably up to 25% by weight, based on the total weight of the copolymer.
Preferably, the arm of the star polymer is formed by anionic polymerization to form a living polymer. Anionic polymerization has been shown to give copolymers with a narrow molecular weight distribution (Mw / Mn), eg, a molecular weight distribution of less than about 1.2.

As is well known, and as disclosed, for example, in US Pat. No. 4,116,917, living polymers are a mixture of conjugated diene monomers in the presence of alkali metals or alkali metal hydrocarbons as anion initiators, such as sodium naphthalene. It can be prepared by anion solution polymerization. Preferred initiators are lithium or monolithium hydrocarbons. Suitable lithium hydrocarbons include unsaturated compounds such as allyllithium, metaallyllithium; aromatic compounds such as phenyllithium, trilllithium, xylyllithium and naphthyllithium, and particularly alkyllithiums such as methyllithium and ethyllithium. Included are propyllithium, butyllithium, amyllithium, hexyllithium, 2-ethylhexyllithium, and n-hexadecyllithium. Secondary butyllithium is the preferred initiator. The initiator can be added to the polymerization mixture in two or more steps, optionally with additional monomers. The living polymer is in an olefinically unsaturated state.

The solvent on which the living polymer is formed is an inert liquid solvent such as an aliphatic hydrocarbon such as pentane, hexane, heptane, octane, 2-ethylhexane, nonane, decane, cyclohexane, methylcyclohexane, or benzene. It is an aromatic hydrocarbon such as toluene, ethylbenzene, xylene, diethylbenzene, and propylbenzene. Cyclohexane is preferred. Mixtures of hydrocarbons such as lubricants can also be used.
The temperature at which the polymerization is carried out can be changed within a wide range, for example, in the range of about -50 ° C to about 150 ° C, preferably in the range of about 20 ° C to about 80 ° C. The reaction is preferably carried out in an inert atmosphere, for example nitrogen, and optionally under pressure, for example under a pressure in the range of about 0.5 bar to about 10 bar.
The concentration of the initiator used in the preparation of the living polymer can also be varied over a wide range and is determined by the desired molecular weight of the living polymer.

To produce a star polymer, the living polymer prepared by the above method is reacted with a polyalkenyl coupling agent in a further reaction step. Polyalkenyl couplings capable of forming stellate 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-attracting moieties, such as aromatic nuclei. Such compounds have the property that at least one alkenyl group can react independently with different living polymers, and in this respect are different from conventional conjugated diene polymerizable monomers such as butadiene, isoprene and the like. different. Pure or technical grade polyalkenyl couplings can be used. Such compounds can be aliphatic, aromatic or heterocyclic compounds. Examples of aliphatic compounds include polyvinyl and polyallyl acetylenes, diacetylenes, phosphates and phosphates, and dimethacrylates such as ethylene dimethyl acrylate. Examples of suitable heterocyclic compounds include divinylpyridine and divinylthiophene.

The preferred coupling agent is a polyalkenyl aromatic compound, and the most preferred coupling agent is a polyvinyl aromatic compound. Examples of such compounds include aromatic compounds such as benzene, toluene, xylene, anthracene, naphthalene and jurene, which are substituted with at least two alkenyl groups and preferably directly attached to them. ing. Specific examples include polyvinylbenzene, such as divinyl, trivinyl and tetravinylbenzene; divinyl, trivinyl and tetravinyl ortho-, meta- and para-xylene, divinylnaphthalene, divinylethylbenzene, divinylbiphenyl, diisobutenylbenzene, diiso. Examples thereof include propenylbenzene and diisopropenylbiphenyl. Preferred aromatic compounds are aromatic compounds 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. Divinylbenzene, especially meta-divinylbenzene, is the most preferred aromatic compound. Pure or technical grade divinylbenzene (including other monomers such as styrene and ethylstyrene) can be used. The coupling agent can be used as a mixture with a small amount of added monomer, which increases the size of the nucleus, such as styrene or alkylstyrene. In such cases, the nuclei can be described as poly (dialkenyl coupling agent / monoalkenyl aromatic compound) nuclei, for example poly (divinylbenzene / monoalkenyl aromatic compounds) nuclei.

The polyalkenyl coupling agent should be added after the polymerization of the monomer has been substantially completed, i.e. the coupling agent should be added only after substantially all of the monomer has been converted to the living polymer.
The amount of polyalkenyl coupling agent added can vary over a wide range, but preferably at least 0.5 mol of coupling agent is used per mole of unsaturated living polymer. An amount in the range of about 1 to about 15 mol, preferably about 1.5 to about 5 mol, per mol of the living polymer is preferred. The amount that can be added in two or more steps is usually sufficient to convert at least about 80% to 85% by weight of the living polymer into a star polymer.

The coupling reaction can be carried out in the same solvent as that used in the polymerization reaction of the living polymer. The coupling reaction can be carried out at a temperature within a wide range, for example, in the range of 0 ° C. to 150 ° C., preferably in the range of about 20 ° C. to about 120 ° C. The reaction can be carried out in an inert atmosphere, for example nitrogen, under pressure in the range of about 0.5 bar to about 10 bar.
The star-shaped polymer thus produced has a large number of dense centers or nuclei of crosslinked poly (polyalkenyl coupling agents) and substantially linear unsaturated polymers extending outward from the nuclei. Characterized by the arm. The number of arms can vary significantly, but is typically in the range of about 4-25.

The resulting star polymer can then be hydrogenated using any suitable means. Hydrogenated catalysts such as copper or molybdenum compounds can be used. It is also possible to use a catalyst containing a noble metal or a noble metal-containing compound. Preferred hydrogenated catalysts include Group VIII elements of the Periodic Table of the Elements, namely non-precious metals such as iron, cobalt, and especially nickel, or compounds containing non-precious metals. Specific examples of preferable hydrogenated catalysts include Raney nickel and nickel supported on diatomaceous earth. Particularly suitable hydrogenation catalysts are catalysts obtained by reacting a metal hydrocarbyl compound with an organic compound of any of the Group VIII metals iron, cobalt or nickel, the latter compound being described, for example, in the UK Patent No. As described in Nos. 1,030,306, it contains at least one organic compound attached to a metal atom via an oxygen atom. Preferred hydrogenation catalysts are aluminum trialkyl (eg aluminum diethyl (Al (Et ₃ )) or aluminum triisobutyl) with nickel salts of organic acids (eg nickel diisopropyl salicylate, nickel naphthenate, nickel 2-ethylhexano). Nickel, a saturated monocarboxylic acid, obtained by reacting ate, nickel di-tert-butylbenzoate, an olefin containing 4 to 20 carbon atoms in the molecule with carbon monoxide and water in the presence of an acid catalyst. A hydrogenation catalyst obtained by reacting with a salt) or nickel enolate or phenolate (eg, a nickel salt of nickel acetonyl acetonate, butyl acetophenone). Suitable hydrogenated catalysts are well known to those of skill in the art and the above list is not exhaustive.

Hydrogenation of the stellate polymer is successful in solution and the solvent is inert during the hydrogenation reaction. A mixture of saturated hydrocarbons and saturated hydrocarbons is suitable. Advantageously, the hydrogenated solvent is the same solvent as the polymerized solvent. Suitably, at least 50% by weight, preferably at least 70% by weight, more preferably at least 90% by weight, and most preferably at least 95% by weight of the original olefin unsaturated is hydrogenated.
The hydrogenated star polymer can then be recovered in a solid state from the hydrogenated solvent by any suitable means, for example by evaporating the solvent. Alternatively, an oil such as a lubricating oil can be added to the solution and the solvent can be removed from the mixture thus produced to obtain a concentrate. Suitable concentrates include hydrogenated star polymer VI improvers in the range of about 3% by weight to about 25% by weight, preferably in the range of about 5% by weight to about 15% by weight.

The star-shaped polymer useful in carrying out the present invention can have a number average molecular weight in the range of about 10,000 to 700,000, preferably in the range of about 30,000 to 500,000. As used herein, the term "number average molecular weight" means the number average molecular weight measured by gel permeation chromatography ("GPC") using a polystyrene standard, following hydrogenation. When determining the number average molecular weight of a star polymer using this method, it should be noted that the calculated number average molecular weight is smaller than the actual molecular weight due to the three-dimensional structure of the star polymer. ..

In a preferred embodiment, the star polymers of the invention are derived from isoprene in the range of about 75% to about 90% by weight and butadiene in the range of about 10% to about 25% by weight and also 80% by weight. Butadiene units in excess of are the incorporated 1,4-addition products. In another preferred embodiment, the star polymers of the invention are 1,2-incorporated with butadiene in the range of about 30% to about 80% by weight and 1 of butadiene in the range of about 20% by weight to about 70% by weight. , 4-Contains amorphous butadiene units from 4-incorporation of butadiene. In another preferred embodiment, the star polymer is derived from isoprene, butadiene, or a mixture thereof and also comprises styrene units ranging from about 5% by weight to about 35% by weight.

Typically, star polymers have a shear stability index (SSI) in the range of about 1% to 35% (30 cycles). An example of a commercially available star-shaped polymer VI improver with an SSI of 35 or less is the Infineum SV200 ™ available from Infineum USA LP and Infineum UK Ltd. Is. Other examples of commercially available star-shaped polymer VI improvers with an SSI of 35 or less are Infineum SV250 ™, Infineum SV261 ™, also available from Infinium USA and Infinium UK. ) And Infineum SV270 ™.
Typically, the viscosity modifier can be given in an amount in the range of 0.01% by mass to 20% by mass, preferably in the range of 1% by mass to 15% by mass, based on the mass of the lubricating oil composition.

Optionally, one or both types of viscosity modifiers used in the practice of the present invention may comprise a nitrogen-containing functional group that imparts the ability as a dispersant to the VI improver. One trend in the industry is to use such "multifunctional" VI enhancers in lubricants to replace some or all of the dispersants. The nitrogen-containing functional group can be added to the VI improver by grafting (sensitizing) the nitrogen-or hydroxyl-containing moiety, preferably the nitrogen-containing moiety, to the polymer backbone of the VI improver. Methods for grafting nitrogen-containing moieties onto polymers are known in the art, for example, polymer and nitrogen-containing moieties in the presence of either pure or solvent-containing free radical initiators. Including contacting. The free radical initiator can be produced by shearing (as in an extruder) or by heating a free radical initiator such as hydrogen peroxide.

The amount of nitrogen-containing graft monomer will depend to some extent on the properties of the backbone polymer and the level of dispersibility required of the grafted polymer. In order to impart dispersibility to both the stellate and linear copolymers, the amount of grafted nitrogen-containing monomer should be appropriately about 0.4% by weight to about 2.2% by weight based on the total weight of the grafted polymer. The range is preferably about 0.5% by mass to about 1.8% by mass, and most preferably about 0.6% by mass to about 1.2% by mass.

Methods for grafting nitrogen-containing monomers onto polymer backbones and suitable nitrogen-containing graft monomers are known, for example, US Pat. No. 5,141,996, WO 98/13443, WO 99/21902, US Pat. No. 4,146,489, US Patent. It is described in Nos. 4,292,414 and US Pat. No. 4,506,056 (Similarly, J Polymer Science, Part A: Polymer Chemistry, Vol. 26, 1189-1198 (1988); J. Polymer Science, Polymer Letters, Vol. 20. , 481-486 (1982) and J. Polymer Science, Polymer Letters, Vol. 21, 23-30 (1983) (all by Gaylord and Mehta) and "in the reaction with maleic anhydride and / or peroxide, Degradation and Cross-linking of Ethylene-Propylene Copolymer Rubber on Reaction with Maleic Anhydride and / or Peroxides ”; Gaylord, Mehta and Mehta, J. Applied Polymer Science, Vol. 33, 2549 See also -2558 (1987)).

(ii) Olefin Copolymer In the present invention, an olefin copolymer (OCP) can be used. Examples of ranges in the composition include lower limits of 0.1% to 6% by weight, 0.1% to 5% by weight, 0.1% to 4% by weight, and 1% by weight or 2% by weight.
These can be linear or branched, aliphatic, aromatic, alkyl aromatic, or alicyclic, such as α-olefins and internal olefins, _{2 of C 2 to} C ₃₀ , for example C _{2 to} C ₈ olefins. It can be a copolymer of more than a species of monomer. Often, these are copolymers of ethylene with C _{3 to} C ₃₀ olefins, with particular preference being copolymers of ethylene with propylene. These _{may also be terpolymers of C 6} and higher α-olefin copolymers and styrenes, such as isoprene and / or butadiene, and hydrogenated derivatives thereof.

Preferred OCPs are 15% to 90% by weight, preferably 30% to 80% by weight ethylene and 10% to 85% by weight, preferably 20% to 70% by weight of one or more C ₃ to C. It is an ethylene copolymer containing ₂₈ , preferably C _{3 to} C ₁₈ , and more preferably C _{3 to} C _{8 α-olefin.} Such OCPs may have a crystallinity of less than 25% by weight as measured by X-ray and differential scanning calorimetry. As shown above, copolymers of ethylene and propylene are most preferred. As an alternative to propylene or as other α-olefins suitable in combination with ethylene and propylene for forming terpolymers or tetrapolymers, for example 1-butene, 1-pentene, 1-hexene, 1-hexene, 1-octene, 1-nonene, 1-decene; and branched α-olefins such as 4-methyl-1-pentene, 4-methyl-1-hexene, 4-methylpentene-1, 4,4-dimethyl-1 -Pentene, 6-methylhexene-1, and mixtures thereof.
Also mentioned are ethylene, the C _{3 to} C ₂₈ α-olefins described above, and terpolymers and tetrapolymers of unconjugated diolefins or mixtures of such diolefins.
Non-conjugated diolefins are generally present in the range of 0.5 mol% to 20 mol%, preferably 1 mol% to 7 mol% of the total molar amount of ethylene and α-olefins.

Diluted oil The viscosity modifier is dispersed (eg, dissolved) in the heavy base stock diluent. As described above, the latter 6 to 15 mm ² / sec in scope, preferably has a kinematic viscosity at 100 ° C. in a range comprised 7~14mm ² / sec. Examples of concentrations of viscosity modifiers in heavy basestock diluents include the following range in mass%: 0.05-5, eg 4, 3 or 2; 0.01- A range of 5, 4, 3 or 2, preferably a range of 0.01 to 2; more preferably a range of 1 to 2, for example a range of 1 to 1.5. The main consideration is that the resulting dispersion should have a kinematic viscosity equal to or similar to that of the brightstock oil.

The present invention will be illustrated by the following examples, but the present invention is not limited to these examples.
Prescription Marine Diesel Cylinder Lubricating Oil (MDCL)
Each MDCL has a base value of 18 and 12.4% by weight of Ca; 23% by weight of viscosity modifier, or Brightstock or polyisobutylene as a comparative example; and an oil of 55.6% by weight of lubricating viscosity (of Group I). Included a calcium alkyl salicylate cleaning agent package containing oil (XOM600)). All MDCLs had a TBN of about 70. Detailed formulations are given in Table 1 below.

The following viscosity modifiers were used:
A star-shaped polymer (“star”) in the form of an amorphous styrene-diene copolymer dispersed in either a heavy oil diluent or a light oil diluent; and ・ Either a heavy oil diluent or a light oil diluent An olefin copolymer (“OCP”) in the form of an amorphous ethylene-propylene copolymer dispersed in a diene.
The bright stock used was a Group I bright stock with a kinematic viscosity at 100 ° C above ^{20 mm 2 / sec.}

Trunk piston engine oil (TPEO)
Each TPEO has a base value of 5.8 and 8.9% by weight of Ca; 7% by weight of viscosity modifier, or Brightstock or polyisobutylene as a comparative example; and an oil of 77.1% by weight of lubricating viscosity (of Group II). Included a calcium alkyl salicylate detergent package containing oil (Chevron 600)). All TPEOs had a TBN of 40. Detailed formulations are given in Table 2 below. The viscosity modifier, brightstock and polyisobutylene were the same as in MDCL above.

Tests and Results Samples of the above formulations were tested for carbon deposition properties using the Panel Coker Test and for evaporation loss using the NOACK volatilization test. These tests are described below.

Panel coker test Lubricating oil can deteriorate on hot engine surfaces and leave deposits that could adversely affect engine performance, panel coker testing simulates typical conditions and the oil thus Evaluate the tendency to form good deposits. The oil under this test is splashed onto a heated metal plate by rotating a metal comb-like splasher device in an oil reservoir containing the oil. Deposits are measured at the end of this test period.

The outline of the test method is as follows:
-Heat 225 mL of oil to 100 ° C in an oil bath.
-Place the heated aluminum panel on an oil solution maintained at a temperature of 320 ° C in an inclined state.
-Splash oil against this panel for 15 seconds, then stop splashing for 45 seconds.
・ Continue this intermittent bounce cycle for 1 hour.
-Weigh the panel and calculate the deposit in grams (g).
The NOACK volatilization test determines the evaporation loss of the lubricant under high temperature use. In other respects, this is known as ASTM D-5800.

Table 1-MDCL with large amounts of Group I oil (XOM600)

Table 1 shows that replacement of brightstock with either a stellate polymer or an olefinic copolymer reduces the amount of deposits in the panel coker test. Table 1 also shows that the use of higher viscosity diluents for stellate polymers and olefin copolymers reduces evaporation loss (ie, lubricant consumption) compared to the use of lower viscosity diluents. Is also shown.
In the table, a check mark indicates that a specific component is present, and a blank indicates that a specific component is not present.

Table 2-TPEO with large amounts of Group II oil (Chevron 600)

Table 2 shows that replacement of brightstock with either a stellate polymer or an olefinic copolymer reduces the amount of deposits in the panel cocker test. Table 2 also shows that the use of higher viscosity diluents for stellate polymers and olefinic copolymers reduces evaporation loss (ie, lubricant consumption) compared to the use of lower viscosity diluents. It also shows that.
Examples 1 to 4 are examples that fall within the scope of the present invention. Examples A to D and W to Z are comparative examples.

Claims (8)

Two-stroke marine engine lubricating oil composition manufacturing method
Lubricating viscosity oil with kinematic viscosity at 100 ° C at a large amount of 3 to 15 mm ^{2 / sec and the following components:}
(A) Each small amount of one or more additives; and
(B) a viscosity modifier in front Symbol 0.1-3 wt% of the amount of the core and form the star polymer over that includes a plurality of polymeric arms extending from the core of the lubricating oil composition, 6 to 15 mm ² Includes the step of blending with a viscosity modifier dispersed in a diluent oil having a kinematic viscosity at 100 ° C. at / sec.
In the star polymer, the arm of the polymer is a hydrogenated isoprene-butadiene copolymer, a hydrogenated styrene-isoprene-butadiene copolymer, a hydrogenated isoprene-styrene copolymer or a hydrogenated butadiene-styrene copolymer. Including
The star polymer has a number average molecular weight in the range of about 10,000 to 700,000 and has a number average molecular weight.
Here, the two-stroke marine engine lubricating oil composition is characterized by having a TBN in the range of 40-100 as measured using ASTM D2896.
2-stroke marine engine lubricating oil composition manufacturing method. The method of claim 1, wherein the composition comprises less than 0.5% by weight of bright stock. The method according to claim 1 or 2, wherein the viscosity modifier (B) is present in the composition in an amount in the range of 0.01 to 40% by mass. The method according to any one of claims 1 to 3 , wherein the composition is in the form of a marine diesel cylinder lubricating oil. Comprising were measured using ASTM D2896, to improve the carbon deposition characteristics of the marine diesel cylinder lubricant having a TBN in the range comprised from 40 to 100, a plurality of polymeric arms extending from (B) core and the core a viscosity modifier in the form of a star-shaped polymer over, 6 to 15 mm ² / s, in the use of the viscosity modifier is dispersed in the diluent oil having a kinematic viscosity at 100 ° C., the star polymer is Used in an amount of 0.1-3% by mass of the resulting lubricating oil,
In the star polymer, the arm of the polymer is a hydrogenated isoprene-butadiene copolymer, a hydrogenated styrene-isoprene-butadiene copolymer, a hydrogenated isoprene-styrene copolymer or a hydrogenated butadiene-styrene copolymer. Including
The use, wherein the star polymer has a number average molecular weight in the range of about 10,000 to 700,000 . A crosshead marine diesel engine comprising a step of supplying the composition obtained by the method according to any one of claims 1 to 4 to a piston / cylinder of a crosshead marine diesel engine. Lubricating method. One of claims 1 to 4 , wherein the oil having a lubricating viscosity contains 50% or more, for example, substantially all of the basestock, wherein the basestock contains 90% or more saturated material and 0.03% or less sulfur. The method described in item 1. Oil of the lubricating viscosity is 50% or more, for example, comprise a base stock as substantially all, wherein the base stock comprises a sulfur exceeding saturates and / or 0.03% of less than 90% of the claims 1-4 The method described in any one of the items.