NL8201866A - LUBRICATING OIL COMPOSITION. - Google Patents

Description

** »i J; YO 3298

Saeeroil composition.

The invention relates to lubricating oil compositions which provide a significant improvement in the fuel economy.

More particularly, the invention relates to lubricating oil compositions containing minor amounts of a glycerol fatty acid acetate additive to save fuel. The industry is currently striving to provide lubricating oil formulations that provide a reduction in fuel consumption for petrol and diesel motor vehicles. To meet. To meet this goal, a new category of additives, commonly referred to as fuel economy additives, has been developed which have the primary task of increasing the number of kilometers achieved per unit fuel volume. Since the current lubricating oil compositions are already complex mixtures, such additives should be compatible with the other components of these compositions and should not adversely affect the many other functions of conventional lubricating oil additives, such as dispersibility, viscosity stability, corrosion and oxidation inhibition and the like.

Examples of recent patents that reflect developments in this area include U.S. Patents Nos. 201,68L and Il. 208,293. These patents describe the use of fatty acid-2O amides and sulfurized amides as additives that provide fuel savings, as demonstrated by friction reduction data. The present invention relates to the use as such fuel-saving additives of glycerol fatty acid esters, in particular glycerol esters of C 1 -C 2 Q fatty acids. The prior art describes the use of such materials and lubricating oil compositions, which is discussed below.

German patent application P-29 ^ 9 910 and P-29 h9 9 ^ 0 from Chevron Research Co. published July 3, 1980 describe the use of glycerol fatty acid esters as fuel-saving additives. These publications correspond to U.S. Patent Applications Nos. 970,698 and 970,699, both of which were filed by Liston on December 18, 1978. These references state that the addition of 0.25 -2 wt.%, Preferably 0.05 wt. - 1.25 wt.%, Of a fatty acid ester will yield a 2-3% fuel saving for both gasoline and diesel engines. 8201866! I --'----- Λ 2 run. Glycerol oleic acid esters are preferred. German patent application P-29 ^ 9 9k0 illustrates the preferred embodiment, namely the use of the glycerol ester at the same treatment level in combination with zinc dihydrocarbyldithiophosphate additives. Contrary to the requirements of these references, the present invention, which has been created by testing engines with fully mixed blends, is based on the discovery that very low levels of glycerol esters, ie up to about 0.2 wt. $, delivering optimum performance expressed in a current evaluation of fuel economy data. There is no benefit from using relatively higher amounts, and in some cases a significant reduction may be somewhat. concerns the stability of the mixture or an adverse performance.

Another reference describing the use of polycarboxylic acid esters in lubricating oil compositions is US Pat. No. 3,933,659, which discloses a multi-component functional liquid, one component of which may be a polyester friction modifier or a fatty acid amide friction modifier. The main application, described there, is for automatic transmission fluids. U.S. Pat. No. 3,273,891 discloses antiwear additives comprising a mixture of dimer acids and a partial ester of a polyhydric alcohol, it being noted that the additive improves lubrication and also acts as an antiwear agent. US 3,112,271 discloses glyerol monooleate as an extreme pressure additive, as also disclosed in U.S. Pat. Nos. 3-112,269 and 3-0U1.28U.

U.S. Patent No. 2 U93.WJ3 discloses marine engine lubricants containing a partial ester of glycerol or other polyol fatty acid esters in amounts of about 0.05 - 1J. Other references describing polyol esters of fatty acids are represented by United States Patent 3,788,326, which describes these compounds as useful for extreme pressure lubricants and United States Patent 2,527-889, which describes the same polyol esters, such as glyerol monooleate and indicates that they are useful as anti-corrosion agents in turbine oil, in diesel fuels .

8201866

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The present invention is based on the discovery that there is a certain range of additive concentration in connection with the use of polyesters in crankcase lubricating oil compositions which have a. degree of fuel savings per unit weight imparts additives, which have hitherto not been recognized, when glycerol esters are used in a fully formulated lubricating oil and are evaluated according to running engine tests. The fact is of equal significance; that other desirable effects and properties of lubricating oils, such as compatibility, detergent ability and dispersibility, are not impaired.

According to the present invention there is provided a fuel saving promoting lubricating oil composition comprising an oil of lubricating oil viscosity and as a fuel-saving additive 0.05-0.2% by weight of a glycerol moiety of a -C 2 g fatty acid, thereby achieving a fuel saving improvement of about 1-3% compared to the same lubricating oil composition without the fuel-saving additive.

The lubricating oil compositions of the invention include direct quality and multi-quality lubricating oil compositions for both gasoline and diesel (pressure ignition) engines. Thus, in the practice of the present invention, the lubricating oil compositions containing additive systems will be formulated to meet the viscosity requirements or other conditions necessary for classification as a gasoline engine or diesel lubricating oil. A direct grade lubricating oil composition will normally include the usual amounts of an ashless dispersant, a normal or basic metal detergent, an antiwear additive and an antioxidant, while a mutton grade oil in addition to the aforementioned viscosity index improver or viscosity modifier. will contain resource. In addition to these main additives, very small amounts of other special purpose additives such as pour point depressants, rust inhibitors, anti-foaming agents, and the like can be mixed in the oil compositions as usual.

The fuel-saving additive of the present invention is preferably a glycerol mono- or di-ester of a saturated or unsaturated C 1 -g fatty acid, such as oleic acid or linoleic acid. Optimal efficiency is found at about 0.2% by weight level and the use of an amount of courts at this level may even be detrimental to the overall performance of the lubricating oil composition.

Crankcase oil compositions to which the present invention pertains are those which contain a major amount of a lubricating oil and effective amounts of conventional additives in addition to the aforementioned fuel-saving additive. The percentages of the additives as described herein are based on weight, based on the total weight of the lubricating oil composition, unless otherwise indicated. These conventional additives include an ashless dispersant, which is typically a nitrogenous dispersant additive, consisting of oil-soluble salts, amides, imides and esters made of high molecular weight mono- and dicarboxylic acids and various amines with an amino or heterocyclic nitrogen group having at least an amido or hydroxy group capable of salt, amide or ester formation. Preference is given to the reaction products of polyolefin (C 1 -C 12 olefin) such as polyisobutenyl succinic anhydride with an alkylene polyamine such as tetraethylene pentamine. The polyisobutenyl part has between 50 and 250 carbon atoms. The alkylene polyamines are those represented by the formula wherein n 2 or 3 and m is a number from 0 to 10.

Mixtures of alkylene polyamines similar to tetraethylene pentamine are commercially useful or used materials. Dispersants are generally used in amounts of about 0.1-10 wt.%, Preferably in the range of about 0.5-5 wt.%, Based on the weight of the lubricating oil composition.

Detergents useful in the compositions include the normal, basic, or overbased metal, ie, calcium, magnesium, etc. salts of petroleum nefcenic acids, petroleum sulfonic acids, alkylbenzene sulfonic acids, alkyl phenols, alkylene bisphenols, oil-soluble fatty acids , and such. The preferred materials are the normal or overbased calcium or magnesium phenates, sulfurized phenates and / or sulfonates, these metallic detergent additives typically being used in an amount of about 1-3% by weight based on the total weight of the lubricating oil compositions .

Examples of suitable oxidation inhibitors are hindered. ,; 5 third phenols, such as 2,6-di-tertiary butyl paracresol, amines, sulfurized phenol, and alkylphenothiazines; usually a lubricating oil will contain about 0.01-3 "of an oxidation inhibitor" depending on its effectiveness.

Suitable pour point depressants, which are usually present in amounts of about 0.01-1% by weight, include wax alkylated aromatic hydrocarbons, olefin polymers and copolymers, acrylate and methacrylate polymers, and copolymers.

inti-wear additives are generally the oil-soluble zinc dihydrocarbyldithiophosphates with at least 5 carbon atoms in total, the alkyl group preferably containing 2-8 carbon atoms. These are usually present in the lubricating oil in amounts of about 0.01-5 wt.%, Preferably 0.5-1.5 wt.%.

Suitable conventional viscosity index improvers or viscosity modifiers are the olefin polymers, such as polybutylene, ethylene-propylene copolymers, hydrogenated polymers and copolymers, and terpolymers of styrene with isoprene and / or butadiene, polymers of alkyl acrylates or alkyl methacrylates of alkyl copolymers. N-vinylpyrrolidone or dimethylaminoalkyl methacrylate, ethylene-propylene polymers grafted with an active monomer, such as maleic anhydride, which can be further reacted with an alcohol or an alkylene polyamine, styrene-maleic anhydride polymers, which are further reacted with alcohols and amines and such. These additives are used in amounts of about 1.5-15 wt., Depending on the precisely desired viscosity specifications.

Suitable hydrocarbon base materials are mineral oils with lubricant viscosity, as measured according to ASTM D-55, of about 2 - U0, preferably 5-20 centistokes at 99 ° C.

These conventional additives are used in amounts normally necessary to provide their functions in a composite crankcase lubricating oil composition. Very small amounts of additional special purpose additives, such as anti-foaming agents or rust inhibitors, may also be present in a fully formulated lubricating oil composition.

The invention is further illustrated by the following examples, which are not intended to be limiting.

8201866 - \ \ l \ 6

Example I '

The reference oil used in this example was a composite straight grade 20W30 crankcase mineral lubricating oil (equivalent to ASTM "HR" oil), containing 0.2% by weight of a glycerol mono-5 oleate. (GMO) fuel-saving additive or 0.2% by weight of a fuel-saving additive consisting of a mixture (GM0 / GD0) of glycerol mono oleate. and glycerol dioleate in a weight ratio of 3 parts of GMO to 2 parts of GDO was added in said mixture. The reference oil contained 2.10 wt% dispersant, 1.10 wt% antioxidant, 1.00 wt% basic metal detergent, 1.95 wt% anti-wear additive, 0.21 wt% pour point depressant, and 0.001 wt% anti-foaming agent. This type of reference oil, which is widely accepted in industry to determine fuel economy data, provides a reproducible basis against which to measure fuel-saving benefits and is expected to provide 15 test results that accurately reflect the effect of a given fuel economy reflect additive.

Fuel economy was evaluated with the Laboratory Engine Fuel Economy (LEFET) summarized here as follows:

The fuel economy test that was used is an ignition engine procedure. The engine is a 5 * 0 1, V-8 Chevrolet engine paired with a water-cooled electric dynamometer. The engine is run with a dry oil pan using external oil pumps. One pump supplies oil to the oil lines from an external oil reservoir, and a second pump pumps the pan dry and returns the oil to the external oil reservoir. The conditions under which the engine runs are as follows:

Condition Speed Load Temperature (° C) _ (turn) (in kg) coolant oil 1 (freewheel) a 800 180 80 98 30 2 (1 + 8 km / h) b 1200 203 80 98 3 (½ km / h) a 1200 U05 80 98 k (88 km / h) ^ 2200 1 * 05 80 98 a - engine load higher than road load b - engine load equivalent to road load.

35 Results are expressed as a percentage 8201866 7 improvement over άβ reference oil. The results at the 0.2 wt% treatment level for both GMO and the GMO / GDÖ mixture are shown in Table A.

TABLE · A - LEFEl · 1 results

Fuel string, $

.5 Engine condition GMO GMO / GDO

1 b, 0 2.6 2 2.5 3.0 3 1.5 1.8 h 0.9 0.6 10 weight average 1.9 1.8

Example II

a) Comparable evaluations using increasing amounts of the GMO / GDO mixture, ie at the 0.3 wt% and 0.5 wt% level, showed no increase in fuel economy benefits in the treatment at these levels, and in some cases, an adverse effect on fuel economy or other lubricating oil performance criteria, such as a tendency for increased piston deposit formation or poor results in bearing corrosion tests.

b) The coefficient of friction (CF) was tested using a Roxana four-ball wear meter according to the procedure described in ASHM D-226-6T "at 110 ° C, 2.5 rpm for both 15 kg and 3 kg and was performed with a compound mineral oil (base oil) containing usual amounts of dispersant ($ 2.12), basic metal sulfonate ($ 1.02), antioxidant ($ 0.72), anti-wear additive 25 ($ 1.98) ) and viscosity index improver (only present in an amount of 8.7 wt.% in test oils 5 and 6 to evaluate compatibility) to which various amounts of the GDO / GMÖ mixture had been added. additional friction reducing benefits at levels above 0.2 wt.% and at 0.9 30 wt.% haze were observed in the trial, which is evidence of potential instability and incompatibility.

8201866 8 TABLE B - CF Results

CF (15 kg) CF (3 kg) test oil Compatibility, 1. Base oil 0.23 0.19 clear 2. Base oil + 0.18 0.1¾ clear

0.1 * GDO / GMO

5 3- Base oil + 0.11 0.11 clear

0.2 * GDO / GMO

U. Base oil + 0.11 0.11 clear

0.3 * GDO / GMO

5. K Base oil + 0.11 0.11 clear

10, k% GDO / GMO

6. Base oil + 0.10 0.10 cloudy

0.9 * GDO / GMO

* 8.7 weight * from a V.I. improver was only present in compositions 5 and 6, since compatibility was important at this concentration.

Example III

(a) The laboratory fuel economy test of Example I was repeated using a 10WU0 multi-grade mineral oil containing 0.09% by weight of the GMO / GDO mixture as the fuel-saving additive. The oil contained about 1% by weight of a multifunctional dispersant viscosity index improver, 0.5 * dispersant, 1.85% of a masical metal detergent, 0.75% by weight of an antiwear additive, and 0.75% by weight of antioxidant.

Table C shows the fuel economy benefits over the oil used as reference in Example I.

TABLE C - Milti-quality oil LEFET.

Results

Engine condition Fuel economy advantage, * 1 5.9 30 2 0.5 3 0.9 ^ 1.1

Weight average 1.8 8201866 9> b) Using the same oil as in Example • HI (a), laboratory fuel economy results were confirmed in the Proposed AS5M 5 Car Interim. Fuel Economy Procedure in which the EPA autocertification cycle was applied in 5 cars with engine dimensions of 2.3-1, 2.8 1. 3, T X and 5.0 1 »Over 5 cars * on average, a fuel saving advantage of 196k% was obtained in each series of fuel economy tests.

8201866

Claims (5)

A lubricating oil composition comprising a major amount of an oil of lubricant viscosity, which contains about 0.05-0.20 wt% of a glycerol moiety ester, or mixtures thereof, of a -C1 g fatty acid, which ester has a fuel saving of 5 yields about 1 - 3%. Composition according to claim 1, characterized in that the fatty acid is oleic acid. The composition according to claim 1, characterized in that said partial ester is a mixture of glycerol monooleate and glycerol di-10 oleate. U. Composition according to claims 1-3 », characterized in that 0.1-0.2 gsvr.% Of said partial ester is present. 5. A composition according to claims 1 - U, characterized in that said lubricating oil composition contains an ashless dispersant, a metal detergent additive, a zinc dihydrocarbyldithiophosphate anti-wear additive and an anti-oxidant. 6. A composition according to claim 5, characterized in that said lubricating oil composition contains a viscosity index improver. 7. Composition according to claims 1-6, characterized in that said composition is a lubricating oil composition for a petrol engine. 8. A composition according to claims 1-6, characterized in that said composition is a diesel engine lubricating oil composition. 8201866 .....................