JP2013129834A - Marine engine lubrication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a marine engine lubricant composition produced by blending MDCL (marine diesel cylinder lubricant) and TPEO (trunk piston engine oil), both of which do not include a bright stock at reduced cost.SOLUTION: There is provided a two- or four-stroke marine engine lubricant composition comprising an oil of lubricating viscosity in a major amount, (A) additives in respective minor amounts, and (B) a viscosity modifier of olefin copolymer. Preferably, the bright stock is completely or substantially not included.

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 while providing improved wear resistance.

We have finally found that the above problems can be overcome by using olefin copolymers such as amorphous ethylene-propylene 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 lubricating oil composition comprising a viscosity modifier in the form of an olefin copolymer in an amount ranging from 0.05 to 6 wt%, wherein Provided is a composition comprising less than 5% by weight, preferably less than 0.1% by weight; preferably 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 trunk piston engine oils or marine diesel cylinder lubricants;
Supplying a lubricating oil composition comprising a viscosity modifier (B) to an engine piston / cylinder assembly; and lubricating the crosshead marine diesel engine; and supplying the composition to the engine; How to lubricate trunk piston marine diesel engines;
including.

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.
Viscosity modifiers provide lubricating oils with high and low temperature operability, allow them to remain relatively viscous at high temperatures, and also exhibit acceptable viscosity or flowability at low temperatures.
In the present invention, an olefin copolymer (OCP) is used. Examples of ranges in the composition include 0.1-6, 0.1-5, 0.1-4% by weight, and a lower limit of 1 or 2% by weight.

These are C ₂ -C ₃₀ olefins, including both α-olefins and internal olefins, which may be linear or branched, aliphatic, aromatic, alkylaromatic, or alicyclic, such as C ₂ It may be a copolymer of two or more monomers of —C ₈ olefins. Often, they are copolymers of ethylene and C ₃ -C ₃₀ olefins, particularly preferred is a copolymer of ethylene and propylene. They may be copolymers of C ₆ olefins and higher alpha olefins, and may be terpolymers of styrene, for example isoprene and / or butadiene, and their hydrogenated derivatives.

Preferred OCPs comprise 15 to 90, preferably 30 to 80% by weight of ethylene and one or more C ₃ -C ₂₈ , preferably C ₃ -C ₁₈ , more preferably C ₃ -C ₈ α-olefins. It is an ethylene copolymer containing 10 to 85, preferably 20 to 70% by mass. Such OCPs may have a crystallinity of less than 25% by weight as determined by x-ray and differential scanning calorimetry. As mentioned above, copolymers of ethylene and propylene are most preferred. Other α-olefins suitable in place of propylene or in combination with ethylene and propylene to form terpolymers or tetrapolymers include, for example: 1-butene, 1-pentene, 1-hexene 1-heptene, 1-octene, 1-nonene, 1-decene; 4-methyl-1-pentene, 4-methyl-1-hexene, 4-methylpentene-1, 4,4-dimethyl-1-pentene Branched chain α-olefins, such as 6-methylheptene-1, and mixtures thereof.

Terpolymers and tetrapolymers of ethylene, the C ₃ -C ₂₈ α-olefins, and non-conjugated diolefins, or mixtures of such diolefins may be included. Nonconjugated diolefins are generally present as 0.5 to 20, preferably 1 to 7 mole percent of the total moles of ethylene and α-olefin.

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 an olefin copolymer in the form of an amorphous ethylene-propylene 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 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 TPEO properties. Viscosity modifiers and bright stock were as used in MDCL. The base oil was a Group 1 base oil.

(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 the use of an amorphous olefin copolymer additive provides advantageous results when compared to bright stock at lower additive processing levels in the formulation.

Claims (17)

A lot of oil of lubricating viscosity,
(A) a small amount of each additive;
(B) a two-stroke or four-stroke marine engine lubricating oil composition comprising a viscosity modifier in the form of an olefin copolymer in an amount ranging from 0.05 to 6% by weight;
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 olefin copolymer is a copolymer of two or more monomers of C ₂ -C ₃₀ olefins. The composition of claim 2, wherein the olefin copolymer is a copolymer of ethylene and a C ₃ -C ₃₀ olefin.   4. A composition according to claim 3, wherein the olefin copolymer is a copolymer of ethylene and propylene. 5. The ethylene copolymer according to claim 1, wherein the copolymer is an ethylene copolymer containing 15 to 90% by weight of ethylene and 10 to 85% by weight of one or more C ₃ -C ₂₈ α-olefins. A composition according to 1.   6. A composition according to any one of claims 1 to 5, wherein the olefin copolymer has a crystallinity of less than 25% by weight as determined by X-ray and differential scanning thermodynamic measurements.   7. A composition according to any one of claims 1 to 6, in the form of a marine diesel cylinder lubricant.   7. A composition according to any one of claims 1 to 6, in the form of a trunk piston engine oil.   7. Any one of claims 1 to 6 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. Use of the viscosity modifier (B) described in the item.   Use according to claim 9, 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 a viscosity modifier (B) in the form of an olefin copolymer as part or all replacement for bright stock.   A method of lubricating a crosshead marine diesel engine comprising supplying the composition of any of claims 1 to 7 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 6 or 8 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 an olefin copolymer 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. 15. The method of claim 14, wherein substantially substitutes for the bright stock.   15. The method of claim 14, wherein the composition comprises less than 0.5 wt% bright stock, preferably less than 0.1 wt%; preferably the composition is completely or substantially free of bright stock. .   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. 17. A method according to any one of claims 14, 15 or 16 having TBN.