Note: Descriptions are shown in the official language in which they were submitted.
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1 lnis invention relates to lubricating oil
2 dispersants which exhibit highly efective dispersant
3 potency in both gasoline and diesel engines. More parti-
4 cularly, the invention rela~es to lubricating oil com-
positions for use both in gasoline and diesel engine
6 formulations which meet current performance requirements
7 ~or both types o~ engines, the formulations being character-
8 ized as containing novel dispersants prepared in a parti-
9 cular reaction sequence.
A current objective in the i~dustry is to
11 provide lubricating oil compositions which meet or exceed
12 engine qualification standards of dispersancy for both
13 gasoline and diesel or compression ignition engines.
14 ~eretofore, dispersants have been developed which meet
one or the other of these requirements, but development
16 of a dispersant which satisfies the highest service
17 classification requirements of the relevant enqine quali-
18 fication tests for both types of oils has not been entirely
19 successful. It is an object of the present invention to
provide lubrica~ing oil compositions containing novel
21 dispersants which meet these goals.
22 The present invention is within the broad
23 field of improved polyolefin, particularly polyisobutenyl,
24 succinic acid or anhydride-polyamine reaction product
dispersants, and such dispersants are disclosed generally,
26 for example, in U.S. Patent 3,172,892 issued March 9,
27 1965 to LeSuer et al.
28 U.S. Patent 3,216,936 issued November 9, 1965 to
29 LeSuer shows lubricating oil additives prepared by acyla
tion of an alkylene amine with both a polyolefin succinic
31 anhydride and an aliphatic monocarboxylic acid, preferably
32 a mono acid having more than 12 carbon atoms such as
33 stearic or oleic acid. The products can be prepared by
3~ reacting both acidic compounds simultaneously with a
polyamine or by first reacting the polyolefin succinic
36 acid with polyamine and subsequently with monocarboxylic
37 acid. The products so formed are said to be particularly
2~i
1 useful in improving the thermal stability of lubricating
2 compositions which contain metal phosphorodithioates.
3 British Patent 1,018,982 (1966) discloses
4 lubricating oil additives which are the reaction products
of three components: alkenyl succinic anhydrides, poly-
6 amines and ca~boxylic acids and the products are said to
7 have improved sludge dispersant properties. The alkenyl
8 succinic anhydrides are those similar to the materials
g of the present invention, i.e., preferably polyisobutenyl
succinic anhydrides and the polyamines are also similar,
11 i.e., the alkylene polyamines. The carboxylic acids of
12 this reference are disclosed as being mono- or di~ car-
13 boxylic acids having 1 to 30, preferably 1 to 18 carbon
14 atoms, with acetic acid being preferred since it forms
an imidazoline or pyrimidine with a minimum of carbon
16 atoms. This reference also states that lower molecular
17 weight carboxylic acids are more effective in promoting
the sludge dispersing activity of ~he final product.
18 The preparative method disclosed in British Patent
19 1,018,9B2 comprises either ~irst reacting the carboxylic
acid and the polyamine in what is described as an imida-
21 zoline or pyrimidine forming reaction with subsequent
22 reaction with alkenyl succinic anhydride or by reacting
23 the three materials simultaneously.
24 U.~. Patent 3,415,750 issued December 10, 1968
to Anzenberger discloses lubricant additives categorized
26 as imida201ines which are prepared by reacting a poly-
27 ethylene polyamine with a mono-carboxylic acid or a di-
28 carboxylic acid to form a heterocyclic imidazoline
29 intermediate which is subsequently reacted with a poly-
alkenyl succinic anhydride to provide a bis-imidazoline
31 which is said to have improved detergency and dispersancy
32 in lubricating oil formulations.
33 U.S. Patent 3,374,174 issued March 19, 1968 to
34 LeSuer discloses lubricant additives prepared by reacting
amines, including alkylene polyamines, with both a high
-- 3
1 molecular weight saturated monocarboxylic acid and a
2 dicarboxylic acid or anhydride, preEerably those having
3 up to 12 carbons. The paterlt discloses the simultaneous
4 reaction of all three materials or a sequential process
whereby there is first formed an acylated amine inter-
6 mediate with the amine and high molecular weigh~ carboxy-
7 lic acid which is subsequently reacted with the dicarboxy-
8 lic acid reactant.
9 U.S. 4,173,540 discloses the reaction of poly-
isobutenyl succinic anhydride with polyamines in a molar
11 ratio of 2.0 to 2.5 moles of anhydride per mole of poly-
12 amine to provide a diimide dispersant, however, such
13 products will not meet the requirements for both gasoline
14 and diesel engine formulations.
U.S. 3,401,118 discloses reacting tetraethylene
16 pentamine first with polyisobutenyl succinic anhydride
17 (PIBSA) derived from 850-1200 ~n polyisobutylene and then
18 reacting this intermediate with PIBSA derived from poly-
19 isobutylene of 400-750 ~n; the 400 ~n corresponding to 29
carbon atoms.
21 The present invention distinguishes from these
22 references in requiring a particular reaction sequence
23 characterized by the use of a dicarboxylic acid anhydride
24 in the final step and an overall mole ratio of anhydride to
polyamine within a relatively narrow and critically defined
26 range. These parameters have been found essential to pro-
27 vide lubricating oil compositions which give demonstrated
28 performance values in engine tests required to qualify for
29 the highest grade service classifications for both gasoline
and diesel engine lubricating oils. The reaction sequence
31 is particularly critical; thus products prepared in a
32 simultaneous reaction technique will not meet the objectives
33 of this invention.
34 In accordance with this invention, there are
provided lubricating oil compositions exhibiting improved
36 dispersancy in both gasoline and diesel engines comprising
37 a major amount of lubricating oil and an effective amount
-- 4
1 of a polyalkenyl succinimide dispersant, said dispersant
2 being prepared in a two-step sequential process comprising
3 (a) ~irst reacting a polyalkenyl succinic anhydride, the
4 polyalkenyl being a polymer of a C3 or C4 olefin,and an
alkylene polyamine of the formula H2N(CH2)n(NH(C~2)n)mNH2,
6 wherein n is 2 or 3 and m i9 0 to l0 in a molar ratio of
7 about l.0 to 2.2 moles of succinic anhydride per mole o~
8 polyamine, and (b) reacting the product of step (a) with
9 a di-carboxylic acid anhydride selected from the group
consisting of maleic anhydride, succinic anhydride and
11 Cl-Cl8, preferably C8-Cl8,alkenyl or alkyl succinic
12 anhydrides in sufficient molar proportion to provide a
13 diimide dispersant having a total mole ratio of about
14 2.3 to 3.0 moles of anhydride per mole of polyamine.
The polyalkenyl succinic anhydrides useful in
16 the present invention ~enerally comprise those whecein
17 the polyalkenyl group has a ~n (number average molecular
18 weight~ of about 700 to 5,000, preferably 900 to 2,000.
19 The methods of preparation are well known in the art,
i.e., reaction of maleic anhydride with either the poly-
21 olefin itsel~ or with a chlorinated polyolefin which in
22 either case provides the desired polyalkenyl succinic
23 anhydride. Polyisobutylene is preferred but other polymers
24 of C3 or C4 olefins such as polybutene-l and polypropylene
are suitable includinq mixtures of such polyolefins.
26 Suitable alkylene polyamines are also well
27 known represented by the formula NH2(CH~)n(NH(CH2)n)mNH2,
28 wherein n is 2 to 3 and m is 0 to l0. Illustrative are
29 ethylene diamine, diethylene triamine, triethylene tetra.mine,
tetraethylene pentamine, pentaethylene hexamine, and the
31 like. Preferred for use is tetraethylene pentamine or a
32 mixture of ethylene polyamines which apptroxima~es tetra-
33 ethylene pentamine such as "DOW E-l00" (~a commercial
34 mixture available from Dow Chemical Company, Midland,
Michigan).
36 The terms polyalkenyl succinimide dispersant
37 or diimide dispersant as used herein is meant to encompass
1 the co~pleted reaction product of the sequential process
2 and is intended to encompass compounds wherein the product
3 may have amide, amidine or salt linkages in addition to
4 the Lmide linkage which results from the reaction of the
primary amino group and the anhydride moiety.
6 The third reactant used to prepare the dis-
7 persants of the present invention encompasses maleic
8 anhydride, succinic anhydride or an alkenyl or alkyl
9 succinic anhydride having up to about 18 carbon atoms
and preferably at least 8 carbon atoms. Particularly
1 advantageous results in terms of engine performance data
12 have been obtained with dodecenyl succinic anhydride and
13 maleic anhydride and the use of these materials, and the
14 dispersants produced thereby, represent particularly
preferred embodiments.
16 In the present invention, both the reaction
1l sequence and the overall final mole ratio of total succinic
18 anhydride groups to polyamine in the finished product
19 have been found to be essential to meet the objective of
passing both engine qualification tests for gasoline and
21 diesel lubricating oil formulations. The reaction sequence
22 requires a first step in the preparation of a polyiso-
23 butenyl succinic anhydride~polyamine reaction product.
24 These are reacted in a mole ratio of about 1.0 to 2.2
moles of polyisobutenyl succinic anhydride per mole of
26 polyamine. After this reaction is complete, suf~icient
27 maleic anhydride, succinic anhydride or alkenyl succinic
28 anhydride is then reacted to provide a final overall
29 mole ratio in the finished dispersant of about 2.3 to
3.0, preferably 2.3 to 2.5, moles of anhydride per
31 mole of polyamine.
32 These reactions are carried out at conventional
33 temperatures of about 80C to 200C, more preferably
34 140C to 165C, using a conventional solvent media, such
as a mineral lubricating oil solvent so that the final
36 product is in a convenient solution in lubricating oil
37 which is entirely compatible with a lubricatin~ oil base
38 stock. Suitable solvent oils are the same as the oils
1 used as a lubricating oil base stock and these generally
2 include lubricating oils having a viscosity (ASTM D-445)
3 of about 2 to qO, preferably 5 to 20,centistokes at
4 99C, with the primarily paraffinic mineral oils being
particularly preferred, such as Solvent 150 Neutral.
6 Lubricating oil compositions are prepared
7 containing the dispersant of the present invention to-
8 gether with conventional amounts of other additives to
g provide their normal attendant func~ions such as viscosity
index improvers, rust inhibitors, metal detergent addi-
11 tives, antioxidants, and zinc dialkyldithiophosphates
12 anti-wear additives and these compositions meet the
13 objective of passing engine qualification tests for both
14 gasoline and diesel engine usage. For gasoline engine
lube oils to meet the current "SF" designation of the
16 American Petroleum Institute, lubricating oil for~ulations
17 must equal or exceed certain values in the MS Sequence VD
18 Engine Test (~STM Special Publication 315). For dispersancy,
19 the significant values in this test are a minimum of 9.4
sludge, 6.7 piston skirt varnish and 6.6 average varnish.
21 The Sequence VD uses a 1980 Ford 2.3 liter 4-cylinder
22 engine and is a 192-hour test comprising the cyclic
23 operation at varying engine speeds and temperatures to
24 simulate "stop and go" city driving and moderate turnpi~e
operation. The test is an established industry standard.
26 For diesel performance the Caterpillar l-H/2
27 test is the current standard to evaluate the effects of
28 a crankcase oil on ring sticking and piston deposits.
29 The t~st simulates high speed, moderately supercharged
engine operation~ This test is also Federal Test Method
31 791-346 and is used to meet military specifications such
32 as MIL-L-21260B and industry specifications such as
33 SAE 183 and General Motors GM6146M. For the 1~-2 Test
34 WTD (Weighted Total Demerits) is the principal value and
for a 240-hour test, the target is a value within or
36 below the 90-100 range. This is derived fro~ the published
37 specification value of WTD 140 for a 480-hour test. WTD
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1 is a cumulative rating based on observation of deposits
2 in the groove and land areas of the piston and lacquer
3 on piston skirts with all the specific evaluation being
4 rated accocding to their relative importance and the
final WTD being calculated in accordance with the test
6 procedure.
7 The dispersants prepared according to the
8 invention can be incorporated in a wide variety of lubricants.
g They can be used in lubricating oil compositions, such
as automotive crankcase lubricating oils, automatic
11 transmission fluids, etc. in effective amounts to provide
12 active ingredient concentrations in finished formulations
13 generally within the range of about 0.5 to 10 weight
14 percentr for example, 1 to 5 weight percent, preferably
1.5 to 3 weiqht percent, of the total composition. Con-
16 ventionally, the dispersants are admixed with the lubricat-
7 ing oils as dispersant solution concentrates which usually
18 contain up to about 50 percent weight of the active
19 ingredient additive compound dissolved in mineral oil,
20 preferably a mineral oil having an ASTM D-445 viscosity
21 of about 2 to 40, prefera~ly 5 ~o 20 centistokes at
22 99C. The lubricatinq oil includes not only hydrocarbon
23 oils of lubricating viscosity derived from petroleum but
24 also includes synthetic lubricating oils such as polyethylene
25 oils; alkyl esters of dicarboxylic acids, complex esters
26 of dicarboxylic acid, polyglycol and alcohol; alkyl
27 esters of carbonic or phosphoric acids; polysilicones;
28 fluorohydrocarbon oils; and mixtures or lubricating oils
29 and synthetic oils in any proportion, etc. The term
"lubricating oil" for this disclosure includes all the
31 foregoing. The useful dispersan~ may be conveniently
32 dispersed as a concentrate of 10 to 80 weight percent,
33 preferably up to about 50 weight percent, of said dispersant
34 in 20 to 90 weight percent of mineral oil, e.g., Solvent lS0
35 Neutral oil with or without other additives being present
36 and such concentrates are a further embodiment of this
37 invention.
2~
1 As noted above, such lubricating oil compositions
2 containing the dispersants of the present invention will
3 also contain other well-known additives such as the zinc
4 dialkyl (C3-Cg)dithiPhsphate anti-wear inhibitors,
generally present in amounts of about l to S weight
6 percent. Useful detergents include the oil-soluble
7 normal basic or over-based metal, e.g., calcium, magnesium,
8 barium, etc., salts of petroleum naphthenic acids, petrol-
9 eum sulfonic acids, alkyl benzene sulfonic acids, oil-
soluble fa~ty acids, alkyl salicylic acids, alkylene
11 bis-phenols and hydrolyzed phosphosulfurized polyolefins.
12 Typical amounts are from l to 7 weight percent with the
13 ~D or diesel oils usually containing slightly more of
14 this metal detergent additive. Preferred detergents are
the calcium and magnesium normal or overbased phenates,
16 sulfurized phenates or sulfonates. Diesel lubricating
17 oils preferably contain 4-6 percent of this additive.
18 Oxidation inhibitors include hindered phenols,
19 e.g., 2.6-ditertbutyl-para-cresol, amines, sulfurized
phenols and alkyl phenothiazines usually present in
21 amounts of from 0.001 to l weight percent.
2~ Pour point depressants which may be present in
23 amounts of from 0.0l to 1 weight percent include wax
24 alkylated aromatic hydrocarbons, olefin polymers and
copolymers, acrylate and methacrylate polymers and copoly-
26 mers-
27 Viscosity index improvers which may vary from
28 about 1 to 15 weight percent depending on the viscosity
29 grade required include olefin polymers such as polybutene,
ethylene-propylene copolymers, hydrogenated polymers and
31 copolymers and terpolymers of styrene with isoprene
32 and/or butadiene, polymers of alkyl acrylates or alkyl
33 methacrylates, copolymers of alkyl methacrylates with N-
34 vinyl pyrrolidone or dimethylaminoalkyl methacryla~e,
post-grafted polymers of ethylene propylene with an
36 active monomer such as maleic anhydride which may be
37 further reacted with an alcohol or an alkylene polyamine,
1 styrene/maleic anhydride polymers post-~reated with
2 alcohols and amines, etc.
3 Rust inhibition activity can be provided by
4 about 0.01 to 1 weight percent of the afore-mentioned
metal dihydrocarbyl dithiophosphates and the corresponding
6 precursor esters,phosphosulfurized pinenes, sulfurized
7 olefins and hydrocarbons, sulfurized fatty esters and
8 sulfurized alkyl phenols. Preferred are the zinc dl-
g hydrocarbyl dithiophosphates which are salts of dihydro-
carbyl esters of dithiophosphoric acids.
11 Other additives include effective amounts of
12 the fuel economy additives or friction reducing additives
13 such as the dimer acid esters, as disclosed in U.S.
14 4,105,571 to Shaub et al, which are present in amounts
of about 1 to 5 weight percent with esters of dimerized
16 linoleic acid and diethylene glycol being a preferred
17 material. Glycerol oleates are another example of fuel
18 economyadditives and these are usually present in very
19 small amounts,such as 0.0S to 0.2 weight percent based
on the weight of the formulated oil.
21 This invention is further illustrated by the
22 following examples which are not to be considered as
23 limitative of its scope.
24 Example 1
1500 grams of PIBSA (polyisobutenyl succinic
28 anhydride,~n=1300, Sap. No. 103) and 170 grams of an
27 ethylene polyamine mixture ("Dow E-100", available from
28 Dow Chemical Company, which approximates tetraethylene
29 pentamine)were reacted in solution in 808 grams of Sol-
vent 150 Neutral, a paraffinic mineral oil, at 160C for
31 3 hours. The mole ratio of succinic anhydride to poly-
32 amine was 1.4:1. Thereafter was added 225 grams of
33 dodecenyl succinic anhydride which provided a final mole
34 ratio of 2.4 moles of anhydride per mole of polyamine
and this was reacted for 2 ~ours at 16~C. Af';er filtra-
36 tion, the product analyzed at 1.83 percent N.
2:~
-- 10 --
1 Example 2
2 320 grams of the inital PIBSA/polyamine product
3 of Example 1 being the same but having a mole ratio of
4 2.1 mole of succinic anhydride per mole of polyamine was
reacted with 6.0 grams of dodecenyl succinic anhydride
6 in Solvent 150 Neutral at 160C for 2 hours to provide a
7 product having a final mole ratio of 2.4 moles of anhydride
8 per mole of polyamine. The product analyzed for 1.50
g percent N.
Exam~le 3
11 Example 2 was repeated except that 2.2 grams
12 Of maleic anhydride was used to provide a product having
13 a final mole ratio of 2.4 moles of anhydride per mole of
14 polyamine. The product analyzed for 1.53 percent N.
Example 4
16 The product of Example 3 was included as the
17 dispersant at a concentration of 3.6 weight percent
18 active ingredient in a formulated SAE lOW40 lubricating
19 oil composition and subjected to the ASTM Sequence V-D
engine test for gasoline engines. The formulation also
21 contained conventional amounts of overbased sulfonate,
22 zinc dialkyl dithiophosphate, antioxidant, olefin copolymer
23 viscosity index improver, rust inhibitor and anti-foam
24 additive. The results were as follows:
Sludge = 9.51; piston skirt varnish = 7.06
26 varnish = 6.92. These results exceed the API "SF" minimum
27 values of 9.4 sludge; 6.7 piston skirt varnish and 6.6
28 varnish and therefore indicate the material is a commercial-
29 ly useful dispersant.
Example 5
31 The products of Example 2 and Example 3 were
32 included in a lOW30 quali~y ~D (diesel) lubricating oil
33 formulations as the dispersant at 2.5 weight percent
34 active ingredient concentration and the oil was evaluated
for diesel dispersancy performance in the Caterpillac 1-
36 H/2 test. The formulation also contained olefin copolymer
37 V.I. improver to provide the lOW30 viscosity grade, 3.1
1 wt. ~ of a mixture of overbased and normal metal phenates,
2 1.5 weight percent of zinc dialkyl dithiophosphate anti-
3 wear additive, and very small proportions of a~ti-oxidant
4 (0.3%) and anti-foamant (0.23).
The results for this diesel engine test are
6 given below:
7 240 Hour Caterpillar l-H/2 Test
8 ~ormulation TGF2 WTD3
g Data Basel 16.6 189.1
10 Example 3 14 66
t1 Example 2 11 98
12 Comparison4 1 183
13 lBase - These data are an average data base used for
14 comparison in evaluating new diesel oils and are an
average of 25 engine tests of conventional formulations.
16 2TGF - Top groove fill, percent deposits in groove.
17 3WTD - Weighted total demerits.
18 4Comparison - The same formulation was tested using as
19 the dispersant a conventional polyisobutenyl succinic
anhydride (Mn=900) - ethylene polyamine (DOW E-100)
21 reaction product dispersant where the anhydride to amine
22 mole ratio was 1.3 to 1.
23 Example 6 (Comparison)
24 The critical nature of the final ratio of
anhydride to polyamine was further demonstrated with
2~ additional Caterpillar 1-~/2 tests. In 11 tests usinq
27 products similar to Examples 3 and 4 but having final
28 mole ratios varying between 1.3 and 2.0, an average WTD
29 value of 163 was obtained. Similarly, for an average of
four engine tests were the final mole ratio was 2.1 to
31 2.2, an average value of 128 WTD was obtained.
