CN102666817A - Lubricating composition - Google Patents

Abstract

The present invention provides a lubricating composition, the lubricating composition at least comprises a base oil and a detergent; wherein the detergent comprises at least 30 mol% BN (base number) of 0.1-80 mg KOH/g based on the total amount of the detergent A sulfonate detergent; wherein the detergent comprises 30-70 mole percent phenate detergent based on the total amount of detergent; wherein the lubricating composition comprises at least 4 wt % detergent based on the total weight of the lubricating composition; wherein The lubricating composition has a TBN (Total Base Number) of at least 10 mg KOH/g (according to ASTM D 2896).

Description

lubricating composition

technical field

The present invention relates to a lubricating composition, in particular to a lubricating composition for use in internal combustion engines operating under sustained high load conditions, such as in marine diesel engines and in power generation applications. More particularly, the present invention relates to a marine lubricant.

technical background

Marine lubricants are known in the art. For example, EP1086195 discloses a marine cylinder oil composition containing a lubricating base oil and an overbased detergent component, the composition has a TBN of 50-90, and the detergent component contains An overbased calcium sulfonate of at least 180 cSt and a TBN of about 400 or greater.

Lubricating compositions applied in internal combustion engines are subject to high stress. It is important that the lubricating composition provide good lubricating properties under a variety of conditions to help keep the engine clean, thermally and oxidatively stable, provide good wear, corrosion protection and remove heat from the engine.

Lubricating compositions employed in marine diesel engines are subject to particularly high stresses due to the long-term continuous operation of marine engines, often at near full load, often in remote locations. Additionally, since there is often little or no opportunity to replace lubricating compositions in marine engines, it is desirable for lubricating compositions to have a long life.

It will be understood in the art that the term "marine" is not limited to those engines used in waterborne vessels. That is, the term also includes engines used for power generation purposes. These advanced, fuel efficient, slow and medium speed marine and stationary diesel engines operate at high pressure, high temperature and long stroke.

Contents of the invention

It is an object of the present invention to improve the deposit-forming properties of lubricating compositions used in particular in internal combustion engines such as marine diesel engines.

Another object of the present invention is to provide an alternative lubricating composition for use in internal combustion engines.

The present invention can achieve one or more of the above-mentioned or other objects by providing a lubricating composition, the lubricating composition at least comprising a base oil and a detergent; wherein the detergent comprises at least 30 mol% BN ( Alkali number) is a sulfonate detergent of 0.1-80mg KOH/g; wherein said detergent comprises 30-70mol% of phenate detergent based on the total amount of detergent; wherein said lubricating composition is based on the total amount of lubricating composition comprising at least 4 wt% detergent by weight; and wherein said lubricating composition has a TBN (total base number) of at least 10 mg KOH/g (according to ASTM D 2896).

According to the present invention it has now been surprisingly found that the lubricating compositions according to the invention exhibit improved deposit formation control properties as determined by DIN 51392 and the Komatsu Hot Tube Test (Komatsu Heat Tube Method).

The base oil used in the lubricating composition of the present invention is not particularly limited, and various conventional mineral oils, synthetic oils and naturally derived esters such as vegetable oils can be conveniently used.

The base oil used in the present invention may conveniently comprise a mixture of one or more mineral oils and/or one or more synthetic oils; thus, in accordance with the present invention, the term "base oil" may refer to mixture. Mineral oils include liquid petroleum oils and solvent-treated or acid-treated mineral lubricating oils of the paraffinic, naphthenic or mixed paraffinic/naphthenic type, which may be further refined by hydrofinishing processes and/or dewaxing.

Suitable base oils for use in the lubricating compositions of the present invention are Group I-III mineral base oils, Group IV polyalphaolefins (PAO), Group I-III Fischer-Tropsch derived base oils, and mixtures thereof.

In the present invention, "Group I", "Group II", "Group III" and "Group IV" base oils refer to lubricating oil base oils as defined by American Petroleum Institute (API) Groups I-IV . These API classifications are defined in API Publication 1509, 15th Edition, Appendix E, April 2002.

Fischer-Tropsch derived base oils are known in the prior art. The term "Fischer-Tropsch derived" means that the base oil is or is derived from a synthetic product of the Fischer-Tropsch process. Fischer-Tropsch derived base oils may also be referred to as GTL (gas-to-liquid) base oils. Suitable Fischer-Tropsch derived base oils which may conveniently be used as base oils for the lubricating compositions of the present invention are, for example, described in EP0776959, EP0668342, WO97/21788, WO00/15736, WO00/14188, WO00/14187, WO00/14183, WO00/ 14179, WO00/08115, WO99/41332, EP1029029, WO01/18156 and WO01/57166.

Synthetic oils include hydrocarbon oils such as olefin oligomers (including polyalpha-based oils; PAOs), dibasic acid esters, polyol esters, polyalkylene glycols (PAGs), alkylnaphthalenes, and dewaxed waxy heterogeneous oils. Construct. The synthetic hydrocarbon base oils sold under the name "Shell XHVI" (trade mark) by the Shell Group may conveniently be used.

Polyalphaolefin base oils (PAOs) and their preparation are well known in the art. Preferred polyalphaolefin base oils for use in the lubricating compositions of the present invention may be derived from linear _C2 - _C32 , preferably _C6 - _C16 alpha-olefins. Particularly preferred starting materials for polyalphaolefins are 1-octene, 1-decene, 1-dodecene and 1-tetradecene.

The total amount of base oil incorporated in the lubricating composition of the present invention is preferably 60-99 wt%, more preferably 65-98 wt%, and most preferably 70-95 wt%, based on the total weight of the lubricating composition.

According to a preferred embodiment of the present invention, said base oil comprises at least 50 wt% of Group II base oil, preferably at least 60 wt%, more preferably at least 70 wt%, based on the total amount of base oil.

There is no particular limitation on the detergent used in the lubricating composition of the present invention (as long as the requirements of claim 1 are met), and various conventional detergents can be conveniently used. The term "detergent" may refer to a single detergent or a mixture comprising two or more different detergents. Examples of detergents that may be used include oil-soluble neutral and overbased sulfonates, phenates, sulfurized phenates, thiophosphonates, salicylates and naphthenates and other oil-soluble metal carboxylates salts of metals, especially alkali metals or alkaline earth metals, such as sodium, potassium, lithium and especially calcium and magnesium. Preferred metallic detergents are neutral and overbased detergents with a TBN (Total Base Number, according to ASTM D 2896) of at most 450 mg KOH/g. Combinations of detergents, which may be overbased detergents or neutral detergents or both, may be used.

As mentioned above, in the composition of the present invention, the detergent comprises at least 30 mol % of a sulfonate detergent with a BN (base number) of 0.1-80 mg KOH/g based on the total amount of detergent. Such relatively low BN sulfonate detergents are well known in the art. For example, WO96/26919 discloses low BN calcium sulfonates and their preparation.

According to a preferred embodiment of the present invention, the detergent comprises at least 35 mol% of sulphonate detergent, preferably at least 40 mol%, more preferably at least 45 mol%, even more preferably at least 50 mol%, most preferably at least 55 mol%. It is also preferred that the sulphonate detergent has a BN of at most 50 mg KOH/g, more preferably at most 40 mg KOH/g.

As mentioned above, in the composition of the present invention, the detergent comprises 30-70mol% of phenate detergent based on the total amount of detergent. The detergent preferably comprises at least 35 mol% of phenate detergent; the detergent preferably comprises at most 65 mol% of phenate detergent, more preferably at most 60 mol%, even more preferably at most 55 mol%, still more preferably at most 50 mol%, most preferably up to 45 mol% phenate detergent. It is also preferred that the phenate detergent is an overbased detergent with a BN of at least 190 mg KOH/g, preferably at least 200, more preferably at least 220, most preferably at least 240 mg KOH/g. Such detergents are well known in the art.

The total amount of detergent in the compositions of the invention is generally up to 35.0 wt%, based on the total weight of the lubricating composition. The composition of the invention comprises at least 4 wt%, preferably at least 8 wt%, more preferably at least 12 wt% detergent, based on the total weight of the composition.

The lubricating composition of the present invention may also contain one or more other additives, such as antioxidants, anti-wear agents, dispersants, other detergents, extreme pressure additives, other friction modifiers, viscosity modifiers, pour point depressants, Metal deactivator, preservative, demulsifier, defoamer, seal compatibilizer and additive diluent base oil, etc. Preferably, in addition to the detergent, at least a dispersant is present in the composition of the invention; more preferably, at least a dispersant and an antiwear agent are present.

Based on the total weight of the lubricating composition, the above-mentioned additives are generally present in an amount of 0.01-35.0 wt%, preferably 0.5-30.0 wt%. More preferably, the lubricating composition of the present invention comprises less than 5.0% by weight of any other additive other than one or more detergents. Preferably, the composition is free of other additives than one or more detergents, one or more dispersants and one or more antiwear agents.

Since the above and other additives are familiar to those skilled in the art, they will not be discussed in detail here. Specific examples of these additives are described, for example, in Kirk-Othmer, Encyclopedia of Chemical Technology, Third Edition, Volume 14, pages 477-526.

Preferably, the composition has a Total Base Number (TBN) value of preferably at most 75 mg KOH/g, preferably at most 70 mg KOH/g, more preferably at most 65 mg KOH/g, even more preferably at most 60 mg KOH/g ( Specifically measured according to ASTM D 2896). The composition has a total base number (TBN) value (according to ASTM D 2896) of at least 10 mg KOH/g.

In addition, it is preferred that the kinematic viscosity (according to ASTM D 445) of the composition at 100°C is greater than 5.6 mm ² /s and less than 21.9 mm ² /s, preferably greater than 12.5 mm ² /s, more preferably greater than 16.3 mm ² /s.

The lubricating compositions of the present invention may conveniently be prepared by admixing one or more additives with a base oil.

In another aspect, the present invention provides the use of a lubricating composition according to the invention to improve deposit formation control performance, in particular measured according to DIN51392.

The lubricating composition of the present invention is generally used for lubricating equipment, but is particularly useful as an engine oil for internal combustion engines. These engine oils include passenger car engines, diesel engines, marine diesel engines, gas engines, two-cycle and four-cycle engines, etc., and especially marine diesel engines.

The invention is described below with reference to the following examples, which do not limit the scope of the invention in any way.

Example

lubricating oil composition

Various lubricating compositions formulated for use as marine cylinder oils in marine diesel engines.

Table 1 lists the composition and properties of the formulations tested; component contents are expressed in wt% based on the total weight of the fully formulated formulation.

All tested marine diesel engine oil formulations were formulated to SAE 50 formulations which meet the so-called SAE J 300 specification (revised January 2009, SAE stands for Society of Automotive Engineers). All formulations tested had kinematic viscosities (according to ASTM D 445) at 100°C of greater than 16.3 mm ² /s and less than 21.9 mm ² /s.

All tested marine cylinder oil formulations contained a combination of base oil, detergent composition and dispersant.

"Base Oil 1" is a blend of a Group I base oil and bright stock commercially available under the tradename "Catenex" from Shell Chemicals Ltd. (London, UK).

"Base Oil 2" is a base oil blend comprising a thickener and 75% by weight Group II base oil; such a blend is commercially available, for example, under the trade designation "Chevron 600R "Commercially available.

"Detergent 1" is an overbased sulfonate detergent with a TBN of 417 mg KOH/g (according to ASTM D 2896) and a soap content of 236 mM Ca ²⁺ manufactured by Chevron Oronite (Windsor, UK) under the tradename "OLOA 249SX" is commercially available.

"Detergent 2" is an overbased sulfonate detergent with a TBN of 375 mg KOH/g and a soap content of 317 mM Ca ²⁺ , sold under the trade name "T106" by JinZhou KangTai Lubricant Additives Co. Ltd. (Liaoning, China) "Commercially available.

"Detergent 3" is an overbased phenate detergent with a TBN of 246 mg KOH/g and a soap content of 397 mM Ca2 ⁺ commercially available from Lubrizol (Wickliffe, Ohio, USA) under the trade designation "Lubrizol 6499".

"Detergent 4" is an overbased phenate detergent with a TBN of 250 mg KOH/g and a soap content of 282 mM Ca2 ⁺ , commercially available from Chevron Oronite under the trade designation "OLOA 219C".

"Detergent 5" is a low BN sulfonate detergent with a TBN of 16 mg KOH/g and a soap content of 410 mM Ca2 ⁺ commercially available from Chevron Oronite under the trade designation "OLOA 246S".

"Detergent 6" is a low BN sulfonate detergent with a TBN of 34 mg KOH/g and a soap content of ³⁹⁵ mM Ca, commercially available under the trade designation "LOBASE C-4503" from Chemtura Corporation (Middlebury, USA) get.

"Detergent 7" is an overbased sulfonate detergent with a TBN of 9 mg KOH/g and a soap content of 441 mM Ca2 ⁺ , commercially available from Chemtura Corporation under the trade designation "LOBASEC-4506".

The "dispersant" was a high MW polyisobutylene succinimide commercially available under the trade designation "HiTEC" from Afton Chemical Corporation (Richmond, VA, USA).

The compositions of Examples 1-10 and Comparative Examples 1-2 were obtained by mixing base oil with detergent and dispersant using conventional lubricant mixing procedures.

Apply the method indicated in Table 1 as follows:

¹ TBN value is determined according to ASTM D 2896;

² The detergent content (or "soap content") of each detergent is described in the article "Separation of lube oildetergent additives on silica gel", in Khimiya i Tekhnologiya Topliv i Masel, No.2, pp.48-52, February, 1980, after the separation procedure described, TAN measurement (according to ASTM D 664) of the soap fraction of the applied detergent is determined. The soap content values determined are expressed in equivalent millimoles of Ca2 ⁺ per kg of detergent additive (see soap content determined above for detergents 1-7). The detergent (molar) content of each detergent type (eg, low BN sulfonate) is obtained by summing the contribution (wt %) of each detergent additive in the overall formulation multiplied by the respective detergent content.

³ The proportion of detergent is determined by calculation (dividing each detergent component by the total) and expressed in mol%. In an embodiment, the sum of the phenate ratio and the sulfonate ratio is 100%; the ratio of low BN sulfonate (ie BN is 0.1-80 mg KOH/g, preferably 0.1-50 mg KOH/g sulfonate) ratio as a fraction of the sulfonate ratio.

^4Nominal deposits are based on total deposit values after testing according to DIN 51392. When compared to Comparative Example 3, it has been shown that nominal deposits (rather than total deposits) better reflect relative values.

Wolf Strip test

In order to verify the deposit formation control performance of the present invention, measurements were carried out according to DIN 51392 using the WolfStrip test procedure (test duration 12 hours, pan temperature 280°C). During the test, the following test conditions were applied: an oil flow rate of 150ml was applied in a closed loop; the oil was pumped in the form of a thin film at a flow rate of 50(±5)ml/h at 280°C on the movable test belt during the test 12 hours, with the inclination of the strips being 8° relative to the horizontal.

The measured nominal deposits are listed in Table 1 above, and the results represent relative amounts compared to the example with the highest total deposit (ie Comparative Example 3).

Komatsu heat pipe test

In an alternative test to verify the deposit formation control performance of the present invention, measurements were made using the Komatsu heat pipe test procedure following the visual rating explained in Swiss Testing procedure No. STS Nr. 452. The Komatsu heat pipe test evaluates the high temperature stability of lubricants. The air inside a heated fine glass capillary tube pushes oil droplets upward, and the film oxidation stability of the lubricant is measured by the degree of varnish formation on the glass tube. The final color of the tube is rated on a scale of 0-10. A rating of 0 indicates heavy deposit formation, while a rating of 10 indicates a clean glass tube at the end of the test. This method is also described in SAE paper 840262. The level of varnish formation in the tubes reflects the high temperature stability of the oil and its propensity to form deposits in high temperature areas of the engine during use. The measured ratings (at 290 and 320°C) are given in Table 2 below.

Table 2

Example 2 Example 3 Example 5 Example 6 Comparative example 1 290°C 9.5 9.5 9.5 9.5 8.5 320°C 5.0 5.0 8.5 8.5 blockage

discuss

It can be seen from Table 1 that the deposit formation control performance of the composition of the present invention is significantly improved when compared with Comparative Examples 1-2.

From the comparison of the deposit formation control performance of Examples 1-10, it can be seen that according to the present invention, it is preferred that at least 40 mol% of the detergent is a low BN sulfonate detergent (i.e. a BN number of 0.1-80, preferably less than 50mg KOH/g) and simultaneously greater than 35mol% detergent total amount is the embodiment of phenate detergent (embodiment 1-7). In addition, Examples 5 and 6 are particularly preferred because they have a smaller amount of deposits. Additionally, it is preferred that the base oil comprises at least 50% by weight of a Group II base oil.

The desirable deposit formation control properties of the present invention were confirmed in the Komatsu heat pipe test (see Table 2). Examples 2, 3, 5, and 6 received excellent ratings (9.5 out of 10 overall rating) at 290°C and were still acceptable (5.0 for Examples 2 and 3) to good (practice Examples 5 and 6 have values of 8.5), while Comparative Example 1 fails the test (blockage) at 320°C.

Claims (10)

1. lubricating composition, said lubricating composition comprises:

Base oil; With

Purification agent;

Wherein said purification agent comprises at least in the purification agent total amount, and 30mol%BN (alkali number) is the sulfonate detergent of 0.1-80mg KOH/g;

Wherein said purification agent comprises the phenates purification agent of 30-70mol% in the purification agent total amount;

Wherein said lubricating composition comprises the purification agent of 4wt% at least in the lubricating composition gross weight; With

The TBN of wherein said lubricating composition (total alkali number) is 10mg KOH/g (pressing ASTMD 2896) at least.

2. the lubricating composition of claim 1, wherein said purification agent comprises the sulfonate detergent of 35mol% at least, is preferably 40mol% at least, and more preferably 45mol% at least most preferably is 50mol% at least.

3. claim 1 or 2 lubricating composition, wherein said sulfonate detergent has the BN of 50mg KOH/g at the most.

4. each lubricating composition of claim 1-3, wherein said purification agent comprises the phenates purification agent of 35mol% at least.

5. each lubricating composition of claim 1-4, wherein said phenates purification agent are that BN is 190mg KOH/g, preferred at least 200, more preferably at least 220, the overbased detergent of 240mg KOH/g at least most preferably at least.

6. each lubricating composition of claim 1-5, wherein said compsn comprises at least 8wt%, is preferably the purification agent of 12wt% at least in the gross weight of compsn.

7. each lubricating composition of claim 1-6, the TBN of wherein said compsn (total alkali number) value is 75mg KOH/g at the most, is preferably 70mg KOH/g at the most, more preferably 60mg KOH/g at the most.

8. each lubricating composition of claim 1-7, wherein said base oil comprises the II class base oil of 50wt% at least in the base oil total amount, is preferably 60wt% at least, more preferably 70wt% at least.

9. each lubricating composition of claim 1-8, wherein said compsn is a marine diesel engine oil.

10. each lubricating composition of claim 1-9 improves the purposes that settling forms control performance.