U.S. patent application number 11/000658 was filed with the patent office on 2006-06-01 for engine flush process and composition.
This patent application is currently assigned to The Lubrizol Corporation. Invention is credited to William D. Abraham, Paul D. Basar, Steven A. Goodlive, John W. Taracha.
Application Number | 20060116297 11/000658 |
Document ID | / |
Family ID | 36087897 |
Filed Date | 2006-06-01 |
United States Patent
Application |
20060116297 |
Kind Code |
A1 |
Basar; Paul D. ; et
al. |
June 1, 2006 |
Engine flush process and composition
Abstract
An internal combustion engine can be cleaned of sludge,
deposits, or wear debris, by supplying to lubricated surfaces of
said engine a composition having a kinematic viscosity of 1 to 10
mm.sup.2/s at 100.degree. C. comprising oil having at least 15%
aromatics by ASTM D-2007; at least 2.5 weight percent of a
nitrogen-containing dispersant; at least 0.6 weight percent of an
overbased metal detergent; and at least about 0.5 weight percent of
a metal salt of a phosphorus acid, circulating the composition
through the engine and removing the composition from the
engine.
Inventors: |
Basar; Paul D.;
(Brecksville, OH) ; Goodlive; Steven A.; (Chardon,
OH) ; Taracha; John W.; (Painesville, OH) ;
Abraham; William D.; (Concord, OH) |
Correspondence
Address: |
THE LUBRIZOL CORPORATION;ATTN: DOCKET CLERK, PATENT DEPT.
29400 LAKELAND BLVD.
WICKLIFFE
OH
44092
US
|
Assignee: |
The Lubrizol Corporation
Wickliffe
OH
|
Family ID: |
36087897 |
Appl. No.: |
11/000658 |
Filed: |
December 1, 2004 |
Current U.S.
Class: |
508/287 ;
508/198; 508/371; 508/372; 508/375; 508/391; 508/460; 508/586 |
Current CPC
Class: |
C10M 2207/026 20130101;
C10M 2203/1045 20130101; C10N 2010/04 20130101; C10M 169/04
20130101; C10M 2223/045 20130101; C10M 2203/1065 20130101; C10N
2040/25 20130101; C10M 169/045 20130101; C10M 2219/04 20130101;
C10M 2219/046 20130101; C10N 2010/02 20130101; C10M 2215/28
20130101; C10M 2227/061 20130101; C10N 2030/04 20130101; C10M
2219/022 20130101; C10N 2030/02 20130101; C10M 171/02 20130101;
C10M 2203/1006 20130101; C10M 2207/281 20130101 |
Class at
Publication: |
508/287 ;
508/198; 508/371; 508/372; 508/375; 508/391; 508/460; 508/586 |
International
Class: |
C10M 141/06 20060101
C10M141/06; C10M 141/10 20060101 C10M141/10 |
Claims
1. A method for removing at least a portion of at least one of
sludge, deposits, and wear debris from the lubricated surfaces of
an internal combustion engine which has accumulated such sludge,
deposits, or wear debris, comprising: (a) supplying to lubricated
surfaces of said engine a composition having a kinematic viscosity
of about 1 to about 9.3 mm.sup.2/s at 100.degree. C. and a flash
point of at least about 125.degree. C., comprising (i) oil having
at least about 15% aromatics by ASTM D-2007; (ii) at least about
2.5 weight percent of a nitrogen-containing dispersant; and (iii)
at least about 0.6 weight percent of an overbased metal detergent;
(b) circulating said composition through the engine; and (c)
removing said composition from the engine.
2. The method of claim 1 wherein the composition is circulated
through the engine by means of running the engine.
3. The method of claim 1 wherein the composition is circulated
through the engine by means of an external pump.
4. The method of claim 1 wherein the composition is circulated
through the engine for about 1 minute to about 1 hour.
5. The method of claim 1 wherein the composition is circulated at a
temperature of about 20 to about 130.degree. C.
6. The method of claim 1 wherein the oil is an API Group I base
stock.
7. The method of claim 1 wherein the oil has a viscosity of about
0.5 to about 7.5 mm.sup.2/s at 100.degree. C.
8. The method of claim 1 wherein the dispersant is a succinimide
dispersant.
9. The method of claim 8 wherein the succinimide dispersant has a
TBN of less than about 45 and a TAN of greater than about 4, on an
oil-free basis.
10. The method of claim 1 wherein the overbased metal detergent
comprises a calcium, magnesium, or sodium sulfonate, phenate,
salicylate, salixarate, or saligenin, or mixtures thereof.
11. The method of claim 1 wherein the overbased metal detergent
comprises a sodium sulfonate.
12. The method of claim 1 wherein the overbased metal detergent
component has a TBN of about 100 to about 800.
13. The method of claim 1 wherein the composition further comprises
(iv) at least about 0.5 weight percent of a metal salt of a
phosphorus acid.
14. The method of claim 13 wherein the metal salt of a phosphorus
acid is a zinc dihydrocarbyldithiophosphate.
15. The method of claim 1 wherein the composition further comprises
a seal swell agent.
16. The method of claim 1 wherein the composition further comprises
at least one additional additive selected from the group consisting
of antioxidants, organic borate esters, and pour point
depressants.
17. The method of claim 1 wherein the composition comprises 0 to
about 0.4% polymeric viscosity modifier.
18. The method of claim 1 wherein the composition is substantially
free from polymeric viscosity modifier.
19. The method of claim 1 wherein the composition is substantially
free from solvent having a flash point of less than 93.degree.
C.
20. The method of claim 1 wherein the engine is a gasoline fueled
engine or a light duty diesel engine.
21. A composition having a kinematic viscosity of about 1 to about
9.3 mm.sup.2/s at 100.degree. C. and a flash point of at least
about 125.degree. C., comprising (a) oil having at least about 15%
aromatics by ASTM D-2007; (b) at least about 2.5 weight percent of
a succinimide dispersant; and (c) at least about 0.6 weight percent
of an overbased metal detergent.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a composition and process
suitable for flushing an internal combustion engine to remove
sludge, deposits, or wear from lubricated surfaces of the
engine.
[0002] There is a need to develop an engine flush lubricant to
clean older engines, typically those with greater than 120,000 km
(75,000 mi.) on the odometer. Among the devices known to be used
for supplying cleaning fluids to engines are those described in
U.S. Pat. No. 5,460,656, among others. There are, indeed, numerous
engine cleaning or flushing compositions available for use, many of
which may contain kerosene, mineral spirits, or other solvents. It
is believed that typical engine flush oils may sometimes contain
60-98% kerosene (also known as Fuel Oil No. 1) or diesel fuel No.
2; 1-15% solvents or light base stocks such as ethylene glycol
monobutyl ether, 2-ethyoxyethanol, solvent dewaxed heavy paraffinic
petroleum distillates (the foregoing may sometimes be present at
75% or more), hydrotreated heavy naphthenic petroleum distillates,
and heavy aromatic petroleum solvent naphtha. These materials can
be volatile or flammable or both, as well as difficult to store and
dispose of. Conventional solvent based flush systems, moreover,
typically do nothing to recondition the surfaces of a cleaned
engine.
[0003] An engine flush oil from The Valvoline Company is reported
on an MSDS dated Jan. 14, 2002 as containing 85.0-95.0% by volume
kerosene, 0.0-10.0% aromatic petroleum distillates, 0.0-9.0%
ethylene glycol monobutyl ether, and 0.0-7.0% diacetone alcohol
(available at http://msds.ashland.com). An "oil system cleaner" [as
apparently distinguished from a "complete oil system flush" also
offered] from Gold Eagle Company, "VS7," is reported on an MSDS
dated May 14, 2003 as containing refined petroleum oil and having a
flash point >93.3C. An internet web site
(http://www.mightyautoparts.com/products/products_vs7_oil.html,
accessed Nov. 1, 2004) states that the VS7 oil system cleaner does
not contain oil-thinning kerosene or mineral spirits.
[0004] The present invention, therefore, solves the problem of
providing an effective engine flush lubricant which can be free
from volatile, flammable solvents and which serves to condition
engine parts.
SUMMARY OF THE INVENTION
[0005] The present invention provides a method for removing at
least a portion of at least one of sludge, deposits, and wear
debris from the lubricated surfaces of an internal combustion
engine which has accumulated such sludge, deposits, or wear debris,
comprising:
[0006] (a) supplying to lubricated surfaces of said engine a
composition having a kinematic viscosity of 1 to 9.3 mm.sup.2/s at
100.degree. C. and a flash point of at least about 125.degree. C.,
comprising [0007] (i) oil having at least 15% aromatics by ASTM
D-2007; [0008] (ii) at least 2.5 weight percent of a
nitrogen-containing dispersant; and [0009] (iii) at least 0.6
weight percent of an overbased metal detergent;
[0010] (b) circulating said composition through the engine; and
[0011] (c) removing said composition from the engine.
[0012] The invention further provides a cleaning composition for an
engine, comprising the components as described above.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Various preferred features and embodiments will be described
below by way of non-limiting illustration.
[0014] The composition employed in the present invention includes
an oil having at least 15% aromatics by ASTM D-2007; at least about
2.5 weight percent of a nitrogen-containing dispersant; at least
about 0.6 weight percent of an overbased metal detergent; and at
least about 0.5 weight percent of a zinc
dihydrocarbyldithiophosphate.
[0015] The oil comprises the major portion of the composition used
for flushing, cleaning, and conditioning the engine. It is
typically a mineral oil, although other types of oils such as
animal oils, vegetable oils, or synthetic oils such as esters,
polyalphaolefins, or oils from hydroisomerization of waxes such as
Fischer-Tropsch materials, can also be used. This will be an oil
having a kinematic viscosity suitable to provide a viscosity of the
entire composition of of 1 to 9.3 mm.sup.2/s (cSt) at 100.degree.
C., or alternatively 2 to 8 or 2.5 to 6 mm.sup.2/s. This viscosity
represents of the overall composition corresponds generally to a
viscosity of the oil itself, apart from the influence of any
additives, of perhaps 0.5 to 7.5 or 1 to 6 or 1 to 5 or 1.4 or 2 to
4.5 mm.sup.2/s at 100.degree. C. If multiple individual oils are
employed, the mixture of oils will have the designated
viscosity.
[0016] The oil should have a significant content of aromatic
component. It is believed that oils having a relatively high
aromatics content will exhibit superior solvent properties for
certain engine surface contaminants, leading to more efficient
cleaning. Aromatics can be determined by ASTM D-2007, and
represents the amount of aromatic content of the oil. The aromatic
content of the oil should be at least 15%; alternatively expressed,
the oil should have less than 85% saturates, assuming that the
amount of polar compounds in the oil is negligible.
(Aromatics+saturates+polar compounds=100% by ASTM D-2007.) In
alternative embodiments, the oil can have 17 to 50% or 20 to 40%
aromatics. If a mixture of oils is used, the mixture should have
the above-described aromatics content. Base oils are commonly
characterized in terms of aromatics content or saturates content,
so this information will generally be readily available for any
given oil. Mineral oils having high aromatics content and thus a
high level of unsaturates will typically be included within the API
Group I classification of base oils or base stocks. Group I is
defined as oils containing more than 0.03% sulfur and/or less than
90% saturates, and having a viscosity index of 80 to 120. The oil
can also contain a certain minor amount of other grade oils such as
synthetic esters, e.g., up to about 15 percent by weight.
[0017] The amount of the oil will typically be the total of the
composition less the amounts of the required and optional
additives, as described below. In certain embodiments the amount of
oil can be 75 to 98 percent or 80 to 96 percent or 85 to 94 percent
by weight of the total formulation. It is noted that many of the
additives commonly used may themselves be customarily provided as
solutions in diluent oil. The amount of diluent oil provided along
with the additives, for calculation purposes, is included in the
total amounts of oil as recited above. The properties of the oil,
in terms of viscosity and aromatics content, should be interpreted
to be those of the entire oil component, including contribution
from diluent oil of the additives.
[0018] The formulation in certain embodiments will contain little
or no volatile or flammable solvents. Typical solvents which may be
avoided include those having a flash point (D-92) of less than
93.degree. C. (200.degree. F) or less than 90.degree. C. or less
than 80.degree. C., or alternatively less than 100.degree. C. or
120.degree. C. or 150.degree. C. Typical solvents which may be
avoided can also include materials which have a normal boiling
point of less than 325.degree. C. or 290.degree. C. or 175.degree.
C. or 165.degree. C. or 135.degree. C. Such materials which may be
avoided if desired include kerosene (flash point 81.degree. C.,
boiling point 175-325.degree. C.) and Cellosolve (2-ethoxyethanol,
flash point 44.degree. C., boiling point 135.degree. C.) as well as
aromatic solvents such as toluene and xylene and aliphatic
hydrocarbon solvents such as mineral spirits. Other solvents which
may be avoided if desired include ketones such as acetone or methyl
ethyl ketone and ethers such as 2-butoxyethanol (flash point
60.degree. C., boiling point 171.degree. C. at 99 kPa) as well as
aromatic distillates in the range of C9 through C16, boiling in the
range of 165.degree. C. to 290.degree. C. The amount of such
solvents in the formulation can be less than 5% or 3% or 1% or 0.5%
or 0.1% by weight. In one embodiment, the formulation is
substantially free from volatile or flammable solvents. The amounts
can also be limited in such a way that the flash point of the
composition as a whole is greater than 125.degree. C. or greater
than 130 or 150 or 180 or 200 or even 210.degree. C.; typically a
mineral oil-based composition will have a flash point of 130 or 135
or 165 up to 300 or 260.degree. C.; certain synthetic compositions
may have a yet higher flash point.
[0019] Other materials present in the composition used in the
present invention include materials which can serve to condition
the lubricated surfaces. Such materials or additives include
nitrogen containing dispersant, overbased metal detergent, and zinc
dihydrocarbyldithiophosphate.
[0020] Nitrogen-containing dispersants are well known in the
lubricant industry and include many of what are known as
ashless-type dispersants. Ashless type dispersants are
characterized by a polar group attached to a relatively high
molecular weight hydrocarbon chain. Typical nitrogen-containing
ashless dispersants include N-substituted long chain alkenyl
succinimides, having a variety of chemical structures including
typically ##STR1## where each R.sup.1 is independently an alkyl
group (which may bear more than one succinimide group, by various
methods of attachment), frequently a polyisobutyl group with a
molecular weight of 500-5000, and R.sup.2 are alkylene groups,
commonly ethylene (C.sub.2H.sub.4) groups. Such molecules are
commonly derived from reaction of an alkenyl acylating agent with a
polyamine, and a wide variety of linkages between the two moieties
is possible beside the simple imide structure shown above,
including a variety of amides and quaternary ammonium salts.
Succinimide dispersants are more fully described in U.S. Pat. Nos.
4,234,435 and 3,172,892. Additionall succinimide dispersants are
those having a N:CO ratio of greater than about 1:1, that is, with
overall excess nitrogen functionality derived from the polyamine,
compared with the carbonyl functionality derived from the succinic
acid groups. Such materials may also be described as high nitrogen
dispersants, containing at least 1.6% or at least 2% nitrogen in
the dispersant (on an active chemical, oil-free basis) and having a
relatively high total base number (TBN) of at least 30, 40, or even
50 (mg equivalent KOH per gram of sample, active chemical basis).
Suitable ranges of TBN can include 5-60 or 15-45. In certain
embodiments, the TBN of the dispersant is less than 45 or less than
40 or less than 30. In certain embodiments, the total acid number
(TAN) is at least 4 or 5. The TAN can be, for instance 4 or 5 to 20
or to 10. Useful materials also include relatively high molecular
weight dispersants, having, for instance alkyl or hydrocarbyl
(polymer) groups with {overscore (Mn)} of greater than 1300.
[0021] Another class of nitrogen-containing dispersant is Mannich
bases. These are materials which are formed by the condensation of
a higher molecular weight, alkyl substituted phenol, an alkylene
polyamine, and an aldehyde such as formaldehyde. Such materials may
have the general structure ##STR2## (including a variety of isomers
and the like) and are described in more detail in U.S. Pat. No.
3,634,515.
[0022] Other nitrogen-containing dispersants include polymeric
dispersant additives, which are generally hydrocarbon-based
polymers which contain nitrogen-containing polar functionality,
such as succinimide functionality, as described above, to impart
dispersancy characteristics to the polymer.
[0023] Dispersants can also be post-treated by reaction with any of
a variety of agents. Among these are urea, thiourea,
dimercaptothiadiazoles, carbon disulfide, aldehydes, ketones,
carboxylic acids, hydrocarbon-substituted succinic anhydrides,
nitrites, epoxides, boron compounds, and phosphorus compounds.
References detailing such treatment are listed in U.S. Pat. No.
4,654,403.
[0024] The nitrogen-containing dispersant will be present in the
composition of the present invention in an amount of at least 2.5
weight percent, or 2.7 to 8 weight percent, or 3 to 7 weight
percent. Either a single dispersant or multiple dispersants can be
present.
[0025] The composition of the present invention will also contain
one or more metal-containing detergents. Metal-containing
detergents are typically overbased materials, or overbased
detergents. Overbased materials, otherwise referred to as overbased
or superbased salts, are generally homogeneous Newtonian systems
characterized by a metal content in excess of that which would be
present for neutralization according to the stoichiometry of the
metal and the particular acidic organic compound reacted with the
metal. The overbased materials are prepared by reacting an acidic
material (typically an inorganic acid or lower carboxylic acid,
preferably carbon dioxide) with a mixture comprising an acidic
organic compound, a reaction medium comprising at least one inert,
organic solvent (e.g., mineral oil, naphtha, toluene, xylene) for
said acidic organic material, a stoichiometric excess of a metal
base, and a promoter such as a phenol or alcohol and optionally
ammonia. The acidic organic material will normally have a
sufficient number of carbon atoms, for instance, as a hydrocarbyl
substituent, to provide a reasonable degree of solubility in oil.
The amount of excess metal is commonly expressed in terms of metal
ratio. The term "metal ratio" is the ratio of the total equivalents
of the metal to the equivalents of the acidic organic compound. A
neutral metal salt has a metal ratio of one. A salt having 4.5
times as much metal as present in a normal salt will have metal
excess of 3.5 equivalents, or a ratio of 4.5.
[0026] Overbased detergents are often characterized by Total Base
Number (TBN). TBN is the amount of strong acid (perchloric or
hydrochloric) needed to neutralize all of the overbased material's
basicity, expressed as potassium hydroxide equivalents (mg KOH per
gram of sample). Since overbased detergents are commonly provided
in a form which contains a certain amount of diluent oil, for
example, 40-50% oil, the actual TBN value for such a detergent will
depend on the amount of such diluent oil present, irrespective of
the "inherent" basicity of the overbased material. For the purposes
of the present invention, the TBN of an overbased detergent is to
be recalculated to an oil-free basis. Thus, for instance, a
detergent composition having an uncorrected TBN of 300 and 40% oil
content could have a TBN (oil-free basis) of 500. Detergents which
are useful in the present invention typically have a TBN (oil-free
basis) of 100 to 800, and in one embodiment 150 to 750, and in
another, 400 to 700. If multiple detergents are employed, the
overall TBN of the detergent component (that is, an average of all
the specific detergents together) will typically be in the above
ranges.
[0027] The overall TBN of the composition, including oil, will
derived from the TBN contribution of the individual components,
such as the dispersant, the detergent, and other basic materials.
The overall TBN will typically be at least 7 or at least 10, or
sometimes even at least 20. The majority of the TBN is typically
contributed by the overbased detergent component. In certain
embodiments which include a sodium sulfonate detergent, the TBN
contribution form the sodium sulfonate detergent can be at least 2
or at least 3. Sulfated ash (ASTM D-874) is another parameter often
used to characterize such compositions. Certain of the compositions
of the present invention can have sulfated ash levels of 0.5 to 5%
or 0.8 to 4% or to 2%, for instance, greater than 0.8%, greater
than 1.0%, or even greater than 2%.
[0028] The metal compounds useful in making the basic metal salts
are generally any Group 1 or Group 2 metal compounds (CAS version
of the Periodic Table of the Elements). The Group 1 metals of the
metal compound include Group 1a alkali metals such as sodium,
potassium, and lithium, as well as Group 1b metals such as copper.
The Group 1 metals can be sodium, potassium, lithium and copper,
and in one embodiment sodium or potassium, and in another
embodiment, sodium. The Group 2 metals of the metal base include
the Group 2a alkaline earth metals such as magnesium, calcium, and
barium, as well as the Group 2b metals such as zinc or cadmium. In
one embodiment the Group 2 metals are magnesium, calcium, barium,
or zinc, and in another embodiments magnesium or calcium. In
certain embodiments the metal is calcium or sodium or a mixture of
calcium and sodium. Generally the metal compounds are delivered as
metal salts. The anionic portion of the salt can be hydroxide,
oxide, carbonate, borate, or nitrate.
[0029] Such overbased materials are well known to those skilled in
the art. Patents describing techniques for making basic salts of
sulfonic acids, carboxylic acids, (hydrocarbyl-substituted)
phenols, phosphonic acids, and mixtures of any two or more of these
include U.S. Pat. Nos. 2,501,731; 2,616,905; 2,616,911; 2,616,925;
2,777,874; 3,256,186; 3,384,585; 3,365,396; 3,320,162; 3,318,809;
3,488,284; and 3,629,109.
[0030] In one embodiment the lubricants of the present invention
can contain an overbased sulfonate detergent. Suitable sulfonic
acids include sulfonic and thiosulfonic acids. Sulfonic acids
include the mono- or poly-nuclear aromatic or cycloaliphatic
compounds. Oil-soluble sulfonates can be represented for the most
part by one of the following formulas:
R.sub.2-T-(SO.sub.3.sup.-).sub.a and
R.sub.3--(SO.sub.3.sup.-).sub.b, where T is a cyclic nucleus such
as typically benzene; R.sub.2 is an aliphatic group such as alkyl,
alkenyl, alkoxy, or alkoxyalkyl; (R.sub.2)-T typically contains a
total of at least about 15 carbon atoms; and R.sub.3 is an
aliphatic hydrocarbyl group typically containing at least 15 carbon
atoms. Examples of R.sub.3 are alkyl, alkenyl, alkoxyalkyl, and
carboalkoxyalkyl groups. The groups T, R.sub.2, and R.sub.3 in the
above formulas can also contain other inorganic or organic
substituents in addition to those enumerated above such as, for
example, hydroxy, mercapto, halogen, nitro, amino, nitroso,
sulfide, or disulfide. In the above formulas, a and b are at least
1.
[0031] Another overbased material which can be present is an
overbased phenate detergent. The phenols useful in making phenate
detergents can be represented by the formula
(R.sub.1).sub.a--Ar--(OH).sub.b, wherein R.sub.1 is an aliphatic
hydrocarbyl group of 4 to 400 carbon atoms, or 6 to 80 or 6 to 30
or 8 to 25 or 8 to 15 carbon atoms; Ar is an aromatic group (which
can be a benzene group or another aromatic group such as
naphthalene); a and b are independently numbers of at least one,
the sum of a and b being in the range of two up to the number of
displaceable hydrogens on the aromatic nucleus or nuclei of Ar. In
one embodiment, a and b are independently numbers in the range of 1
to 4, or 1 to 2. R.sub.1 and a are typically such that there is an
average of at least 8 aliphatic carbon atoms provided by the
R.sub.1 groups for each phenol compound. Phenate detergents are
also sometimes provided as sulfur-bridged species.
[0032] Another detergent can be a salicylate detergent. The
alkylsalicylate can be an alkali metal salt or an alkaline earth
metal salt of an alkylsalicylic acid which can in turn be prepared
from an alkylphenol by Kolbe-Schmitt reaction. The alkylphenol can
be prepared by a reaction of .alpha.-olefin having 8 to 30 carbon
atoms (mean number) with phenol. Alternatively, calcium salicylate
can be produced by direct neutralization of alkylphenol and
subsequent carbonation.
[0033] In one embodiment, the overbased material is an overbased
detergent selected from the group consisting of overbased
salixarate detergents, overbased saligenin detergents, overbased
salicylate detergents, and overbased glyoxylate detergents, and
mixtures thereof. Overbased saligenin detergents are commonly
overbased magnesium salts which are based on saligenin derivatives.
A general example of such a saligenin derivative can be represented
by the formula ##STR3## wherein X comprises --CHO or --CH.sub.2OH,
Y comprises --CH.sub.2-- or --CH.sub.2OCH.sub.2--, and wherein such
--CHO groups typically comprise at least 10 mole percent of the X
and Y groups; M is hydrogen, ammonium, or a valence of a metal ion,
R.sup.1 is a hydrocarbyl group containing 1 to 60 carbon atoms, m
is 0 to typically 10, and each p is independently 0, 1, 2, or 3,
provided that at least one aromatic ring contains an R.sup.1
substituent and that the total number of carbon atoms in all
R.sup.1 groups is at least 7. When m is 1 or greater, one of the X
groups can be hydrogen. In one embodiment, M is a valence of a Mg
ion or a mixture of Mg and hydrogen. Other metals include alkali
metals such as lithium, sodium, or potassium; alkaline earth metals
such as calcium or barium; and other metals such as copper, zinc,
and tin.
[0034] As used herein, the expression "represented by the formula"
indicates that the formula presented is generally representative of
the structure of the chemical in question. However, it is well
known that minor variations can occur, including in particular
positional isomerization, that is, location of the X, Y, and R
groups at different position on the aromatic ring from those shown
in the structure. The expression "represented by the formula" is
expressly intended to encompass such variations.
[0035] Saligenin detergents are disclosed in greater detail in U.S.
Pat. No. 6,310,009, with special reference to their methods of
synthesis (Column 8 and Example 1) and preferred amounts of the
various species of X and Y (Column 6).
[0036] Salixarate detergents are overbased materials that can be
represented by a substantially linear compound comprising at least
one unit of formula (I) or formula (II): ##STR4## each end of the
compound having a terminal group of formula (III) or (IV): ##STR5##
such groups being linked by divalent bridging groups A, which may
be the same or different for each linkage; wherein in formulas
(I)-(IV) R.sup.3 is hydrogen or a hydrocarbyl group; R.sup.2 is
hydroxyl or a hydrocarbyl group and j is 0, 1, or 2; R.sup.6 is
hydrogen, a hydrocarbyl group, or a hetero-substituted hydrocarbyl
group; either R.sup.4 is hydroxyl and R.sup.5 and R.sup.7 are
independently either hydrogen, a hydrocarbyl group, or
hetero-substituted hydrocarbyl group, or else R.sup.5 and R.sup.7
are both hydroxyl and R.sup.4 is hydrogen, a hydrocarbyl group, or
a hetero-substituted hydrocarbyl group; provided that at least one
of R.sup.4, R.sup.5, R.sup.6 and R.sup.7 is hydrocarbyl containing
at least 8 carbon atoms; and wherein the molecules on average
contain at least one of unit (I) or (III) and at least one of unit
(II) or (IV) and the ratio of the total number of units (I) and
(III) to the total number of units of (II) and (IV) in the
composition is about 0.1:1 to about 2:1. The divalent bridging
group "A," which may be the same or different in each occurrence,
includes --CH.sub.2-- (methylene bridge) and --CH.sub.2OCH.sub.2--
(ether bridge), either of which may be derived from formaldehyde or
a formaldehyde equivalent (e.g., paraform, formalin).
[0037] Salixarate derivatives and methods of their preparation are
described in greater detail in U.S. Pat. No. 6,200,936 and PCT
Publication WO 01/56968. It is believed that the salixarate
derivatives have a predominantly linear, rather than macrocyclic,
structure, although both structures are intended to be encompassed
by the term "salixarate."
[0038] Glyoxylate detergents are similar overbased materials which
are based on an anionic group which, in one embodiment, may have
the structure ##STR6## wherein each R is independently an alkyl
group containing at least 4, and preferably at least 8 carbon
atoms, provided that the total number of carbon atoms in all such R
groups is at least 12, preferably at least 16 or 24. Alternatively,
each R can be an olefin polymer substituent. The acidic material
upon from which the overbased glyoxylate detergent is prepared is
the condensation product of a hydroxyaromatic material such as a
hydrocarbyl-substituted phenol with a carboxylic reactant such as
glyoxylic acid and other omega-oxoalkanoic acids. Overbased
glyoxylic detergents and their methods of preparation are disclosed
in greater detail in U.S. Pat. No. 6,310,011 and references cited
therein.
[0039] The overbased detergent can also be an overbased salicylate.
The salicylic acids preferably are hydrocarbyl-substituted
salicylic acids, preferably aliphatic hydrocarbon-substituted
salicylic acids wherein each substituent contains an average of at
least 8 carbon atoms per substituent and 1 to 3 substituents per
molecule. The substituents can be polyalkene substituents, where
polyalkenes include homopolymers and interpolymers of polymerizable
olefin monomers of 2 to about 16, preferably 2 to 6, or 2 to 4
carbon atoms. The olefins may be monoolefins such as ethylene,
propylene, 1-butene, isobutene, and 1-octene; or a polyolefinic
monomer, such as diolefinic monomer, such 1,3-butadiene and
isoprene. In one embodiment, the hydrocarbyl substituent group or
groups on the salicylic acid contains 7 to 300 carbon atoms and can
be an alkyl group having a molecular weight of 150 to 2000. The
polyalkenes and polyalkyl groups are prepared by conventional
procedures, and substitution of such groups onto salicylic acid can
be effected by known methods. Overbased salicylate detergents and
their methods of preparation are disclosed in U.S. Pat. Nos.
4,719,023 and 3,372,116.
[0040] Other overbased detergents can include overbased detergents
having a Mannich base structure, as disclosed in U.S. Pat. No.
6,569,818.
[0041] The amount of the overbased detergent, in the formulations
of the present invention, is typically at least 0.6 weight percent
on an oil-free basis. In other embodiments, it can be present in
amounts of 0.7 to 5 weight percent or 1 to 3 weight percent. Either
a single detergent or multiple detergents can be present.
[0042] The formulation of the present invention will optionally
also contain a metal salt of a phosphorus acid, especially of a
sulfur-containing phosphoric acid. Metal salts of the formula
##STR7## wherein R.sup.8 and R.sup.9 are independently hydrocarbyl
groups containing 3 to 30 carbon atoms are readily obtainable by
the reaction of phosphorus pentasulfide and an alcohol or phenol to
form an O,O-dihydrocarbyl phosphorodithioic acid corresponding to
the formula ##STR8## The reaction typically involves mixing at a
temperature of 20.degree. C. to 200.degree. C., four moles of an
alcohol or a phenol with one mole of phosphorus pentasulfide.
Hydrogen sulfide is liberated in this reaction. The acid is then
reacted with a basic metal compound to form the salt. The metal M,
having a valence n, generally is aluminum, lead, tin, manganese,
cobalt, nickel, zinc, or copper, and most preferably zinc. The
basic metal compound is often zinc oxide, thus typically forming a
zinc dihydrocarbyldithiophosphate (ZDDP), and the resulting metal
compound is represented by the formula ##STR9##
[0043] The R.sup.8 and R.sup.9 groups are independently hydrocarbyl
groups that are typically free from acetylenic and often also from
ethylenic unsaturation. They are typically alkyl, cycloalkyl,
aralkyl or alkaryl group and have 3 to 20 carbon atoms, for
instance, 3 to 16 carbon atoms or up to 13 carbon atoms, e.g., 3 to
12 carbon atoms. The alcohol which reacts to provide the R.sup.8
and R.sup.9 groups can be a mixture of a secondary alcohol and a
primary alcohol, for instance, a mixture of isopropanol and
4-methyl-2-pentanol. Such materials are often referred to as zinc
dialkyldithiophosphates or simply zinc dithiophosphates. They are
well known and readily available to those skilled in the art of
lubricant formulation.
[0044] The amount of the metal salt of a phosphorus acid will
typically be at least 0.5 percent by weight, and in certain
embodiments 0.6 to 3 percent by weight or 0.7 to 2 percent by
weight. Either a single salt (e.g., ZDDP) or multiple salts may be
present.
[0045] The composition used in the present invention may optionally
contain one or more additional additives which are commonly found
in engine lubricants. Such materials can include antioxidants, seal
swell agents, friction modifiers, pour point depressants, viscosity
modifiers, fluidizing agents, corrosion inhibitors, rust
inhibitors, and anti-foam agents.
[0046] Antioxidants include aromatic amines such as those of the
formula ##STR10## wherein R.sup.5 is a phenyl group or a phenyl
group substituted by R.sup.7, and R.sup.6 and R.sup.7 independently
a hydrogen or an alkyl group containing 1 to 24 carbon atoms. In
one embodiment R.sup.5 is a phenyl group substituted by R.sup.7 and
R.sup.6 and R.sup.7 are alkyl groups containing 4 to 20 carbon
atoms. In one embodiment, the amine antioxidant comprises
dinonyldiphenylamine as may be represented by ##STR11## or
alternatively a mixture of nonyl- and dinonyldiphenylamine.
[0047] Antioxidants also include hindered alkyl phenols represented
by the formula ##STR12## wherein R.sup.4 is an alkyl group
containing 1 to 24 carbon atoms and a is an integer of 1 to 5, such
as 2, and the substituents being in the ortho positions to the OH
group. In one embodiment, a hindered phenol can contain t-butyl
groups and can be represented by ##STR13##
[0048] In other embodiments the para position can be occupied by an
alkyl group or by a group linking two such phenolic groups. In yet
another embodiment the para position can be the site of an ester
group. Such hindered phenol esters are disclosed in U.S. Pat. No.
6,559,105, and can be represented by ##STR14## wherein R.sup.3 is
an alkyl group; in certain embodiments the alkyl group can contain
containing 2 to 6 carbon atoms or preferably 2 to 4 carbon atoms or
4 carbon atoms (e.g., an n-butyl group). In other embodiments
R.sup.3 can contain 6 or 8 to 30 carbon atoms.
[0049] Other antioxidants include reaction products of a sulfur
source and a Diels-Alder adduct, which in turn can be prepared from
a dienophile having a carboxylic ester group. The antioxidant
component, if present can be present, for example, in an amount of
about 1%, for instance, 0-3%, 0.1-2%, or 0.5 to 1.5% by weight.
[0050] Seal swell agents include sulfolanes such as isodecyl
sulfolane, or alternatively phthalate esters, which are designed to
keep seals pliable. Sulfolanes may, in one embodiment, be
represented by the general formula ##STR15## where R.sup.1 is a
hydrocarbon radical having at least 4 carbon atoms and each of
R.sup.2 and R.sup.3 is independently hydrogen or a lower alkyl
radical, i.e., containing 1 to 7 carbon atoms. In one embodiment R
and R.sup.3 are both hydrogen. R.sup.1 typically contains 1 to 100
carbon atoms, or 4 to 25 or 6 to 10 carbon atoms. Other seal swell
agents include benzyl esters, lactones, and nitriles, and
specifically materials such as decanolactone,
isodecyl-(bicycloheptyl carboxylactone)-carboxylate, benzyl butyl
phthalate, benzyl C.sub.9-C.sub.11 alkyl phthalate, and
3-decyloxypropionitrile. Such materials are known from U.S. Pat.
No. 4,029,587. The seal swell agent, if present, can be present,
for example, in an amount of 0-2% or 0.01-1% or 0.05-2% or
0.1-1%.
[0051] Friction modifiers are well known and include many materials
that are disclosed, for instance in U.S. Pat. No. 6,528,458 and
references cited therein. Some friction modifiers include fatty
phosphites, fatty acid amides, fatty epoxides, borated fatty
epoxides, fatty amines, glycerol esters (e.g., glycerol
monooleate), borated glycerol esters, alkoxylated fatty amines,
borated alkoxylated fatty amines, metal salts of fatty acids,
sulfurized olefins, fatty imidazolines, condensation products of
carboxylic acids and polyalkylene-polyamines, metal salts of alkyl
salicylates, and amine salts of alkylphosphoric acids. Among the
friction modifiers of interest are organic borate esters. Organic
borate esters include esters of alcohols plus a boron source such
as boric acid. One species of organic borate ester is the so-called
borated epoxides, which are esters formed from the reaction of a
boron source plus an organic peroxide, typically to form a cyclic
or polymeric structure. The friction modifier, if present, can be
present, for example, in an amount of 0.1 to 3 percent by weight or
0.15 to 2 or to 1 percent.
[0052] Certain borate esters, depending on length of the alkyl
chain(s) can function primarily as corrosion inhibitors rather than
friction modifiers. This is particularly true of borate esters
having relatively short alkyl chains such as less than C12, e.g.,
C6 to C10, or about C8, chains. Such materials are described in
greater detail in U.S. Pat. No. 6,605,572, see columns 6-7.
Examples of such borate esters include the reaction product of
boric acid with 2-ethylhexyl alcohol or with alcohols to provide
alkyl groups such as isopropyl, n-butyl, isobutyl, amyl,
4-methyl-2-pentyl, isooctyl, decyl, dodecyl, tetracyl, or phenyl.
Typical amounts of these or other materials useful as corrosion
inhibitors can be 0.1 to 1 percent, or 0.2 to 0.8 percent, or 0.3
to 0.5 or to 0.6 percent
[0053] Pour point depressants are another useful type of additive.
These can comprise substances such as polymethacrylates,
styrene-based polymers, crosslinked alkyl phenols, or alkyl
naphthalenes which are useful for reducing the pour point (the
temperature at which an oil becomes resistant to pouring) of an oil
based composition or lubricant. See for example, page 8 of
"Lubricant Additives" by C. V. Smalheer and R. Kennedy Smith
(Lesius-Hiles Company Publishers, Cleveland, Ohio, 1967).The pour
point depressant, if present, can be present, for example, in an
amount of 0.05 to 0.7 weight percent.
[0054] Viscosity modifiers are well known materials, generally
polymers such as ethylene-propylene copolymers, (meth)acrylic ester
polymers, or styrene- and ester-containing copolymers. Viscosity
materials such as can be present, if desired, which may increase
the 100.degree. C. viscosity of the blend somewhat, while also
permitting control or modification of low temperature viscosity.
However, the low temperature viscosity of the present formulation
may be less critical than that for a conventional lubricant oil,
since it is not contemplated that the present formulation will
normally be used under very low temperature conditions. Thus,
viscosity modifiers may be present at 4% by weight or less, e.g., 0
to 4%, or 0.1 to 2%, or 0.5 to 1%. In one embodiment the
composition is substantially free from viscosity modifier, that is,
its amount is about 0% or no more than 0.4% or 0.2% or 0.1% or
0.05%.
[0055] As used herein, the term "hydrocarbyl substituent" or
"hydrocarbyl group" is used in its ordinary sense, which is
well-known to those skilled in the art. Specifically, it refers to
a group having a carbon atom directly attached to the remainder of
the molecule and having predominantly hydrocarbon character.
Examples of hydrocarbyl groups include:
[0056] hydrocarbon substituents, that is, aliphatic (e.g., alkyl or
alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents,
and aromatic-, aliphatic-, and alicyclic-substituted aromatic
substituents, as well as cyclic substituents wherein the ring is
completed through another portion of the molecule (e.g., two
substituents together form a ring);
[0057] substituted hydrocarbon substituents, that is, substituents
containing non-hydrocarbon groups which, in the context of this
invention, do not alter the predominantly hydrocarbon nature of the
substituent (e.g., halo (especially chloro and fluoro), hydroxy,
alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulfoxy);
[0058] hetero substituents, that is, substituents which, while
having a predominantly hydrocarbon character, in the context of
this invention, contain other than carbon in a ring or chain
otherwise composed of carbon atoms. Heteroatoms include sulfur,
oxygen, nitrogen, and encompass substituents as pyridyl, furyl,
thienyl and imidazolyl. In general, no more than two, preferably no
more than one, non-hydrocarbon substituent will be present for
every ten carbon atoms in the hydrocarbyl group; typically, there
will be no non-hydrocarbon substituents in the hydrocarbyl
group.
[0059] It is known that some of the materials described above may
interact in the final formulation, so that the components of the
final formulation may be different from those that are initially
added. For instance, metal ions (of, e.g., a detergent) can migrate
to other acidic or anionic sites of other molecules. The products
formed thereby, including the products formed upon employing the
composition of the present invention in its intended use, may not
be susceptible of easy description. Nevertheless, all such
modifications and reaction products are included within the scope
of the present invention; the present invention encompasses the
composition prepared by admixing the components described
above.
[0060] The composition as described above is used to flush or clean
an engine, which can be a gasoline, diesel, or natural gas engine,
spark ignited or compression ignited, operating on a 4-stroke
cycle, and being sump lubricated or otherwise lubricated. The
composition is particularly suitable for cleaning a 4-stroke
gasoline (spark-ignited) engine which is sump lubricated, or a
light duty diesel engine (e.g., for passenger cars).
[0061] The method of flushing and cleaning such an engine will
comprise the steps of circulating said composition through the
engine, that is, typically through some or all of those portions of
the engine that are normally exposed to or lubricated by the engine
lubricant; and removing the composition from the engine, along with
whatever sludge, deposits, wear debris and residual used or
contaminated motor oil may be removed by the flushing and cleaning
process. The circulating of the composition through the engine can
be effected by an external pump or circulation device, or
alternatively by circulating the composition as though it were an
engine lubricant, e.g., by running the engine and the associated
oil pump, typically at "idle" or "fast idle" speed. The term
"circulating" includes flushing the engine with the composition,
that is, employing one or more passes of the composition through
the engine, typically multiple passes.
[0062] The time during which the composition is circulated through
the engine will depend to some extent on the degree of cleaning
that is desired; in most cases the time of circulation should not
need to exceed 18 hours. In other embodiments, the time of
circulation can be 1 minute to 1 hour, or 2 to 30 minutes, or 5 to
15 minutes.
[0063] The temperature of the fluid during the flushing and
cleaning operation may likewise be adjusted as desired. If it is
circulated by running the engine at a fast idle speed, the fluid
may be expected to attain the temperature commonly reached by a
lubricant circulated under such conditions. Examples of suitable
temperatures include 20-130.degree. C. or 30-100.degree. C. or
40-80.degree. C., which refers to the sump temperature (temperature
of the bulk oil in the sump).
[0064] After flushing and cleaning of the engine as described above
and removal of the composition of the present invention, the engine
can be charged with a desired conventional lubricant and returned
to service.
EXAMPLES
Example 1
[0065] A composition is prepared in a mixture of base oils (50% 400
N naphthenic oil and 50% 100 N API Group I oil), having a viscosity
at 100.degree. C. of 2.14 mm.sup.2/s and 22% aromatic content, 5%
of a succinimide dispersant, 1% of a hindered phenolic ester
antioxidant, 1.4% overbased calcium and sodium sulfonate
detergents, 1.4% zinc dialkyldithiophosphate, 0.4% trialkyl
(relatively short chain) borate ester, 0.3% sulfurized olefin
antioxidant, 0.1% alkyl sulfone and 10 ppm antifoam agent, all
numbers on a diluent oil-free basis.
[0066] A 3.8 L six-cylinder gasoline engine is evaluated for high
temperature poston deposits by the protocol set forth in ASTM
Sequence IIIG Test Procedure Draft 2D prior to the flushing and
cleaning of the present invention. Each piston is evaluated at the
undercrown, second land, third land, piston skirt, 1.sup.st groove,
2.sup.nd groove, and 3.sup.rd groove positions. The weighted piston
deposit result is determined by multiplying each rated area by the
following weighting factors: TABLE-US-00001 Piston Undercrown 10%
2.sup.nd Land 15% 3.sup.rd Land 30% Piston Skirts 10% Top Groove 5%
2.sup.nd Groove 10% Oil Ring Groove 20%
[0067] A total weighted value for each piston is reported on a
scale of 0 to 10, with 10 representing an entirely clean piston
(higher numbers are better).
[0068] The above composition is circulated through the engine by
supplying 5.50 L of the composition to the sump of the engine and
operating the engine at 1500 r.p.m. for 10 minutes at ambient
engine oil temperature (about 50.degree. C.). After the procedure,
the engine is drained and again evaluated by the above-described
procedure. The results of the evaluation before and after the
flushing procedure are set forth in the table below: TABLE-US-00002
Weighted Piston Summary Before Flush After Flush Piston 1 total
5.51 5.75 Piston 2 total 4.54 4.50 Piston 3 total 3.56 3.80 Piston
4 total 3.50 3.69 Piston 5 total 5.41 5.61 Piston 6 total 5.58 5.84
Overall piston weighted average 4.68 4.86
[0069] The results show that treatment with the composition of the
present invention leads to improvement in the cleanliness of the
engine as measured by the above test. This improvement in
cleanliness is observed even though no volatile or highly flammable
solvents are employed in the composition--it is an entirely
"lubricant based" cleaner.
[0070] Each of the documents referred to above is incorporated
herein by reference. Except in the Examples, or where otherwise
explicitly indicated, all numerical quantities in this description
specifying amounts of materials, reaction conditions, molecular
weights, number of carbon atoms, and the like, are to be understood
as modified by the word "about." Unless otherwise indicated, each
chemical or composition referred to herein should be interpreted as
being a commercial grade material which may contain the isomers,
by-products, derivatives, and other such materials which are
normally understood to be present in the commercial grade. However,
the amount of each chemical component is presented exclusive of any
solvent or diluent oil, which may be customarily present in the
commercial material, unless otherwise indicated. It is to be
understood that the upper and lower amount, range, and ratio limits
set forth herein may be independently combined. Similarly, the
ranges and amounts for each element of the invention can be used
together with ranges or amounts for any of the other elements. As
used herein, the expression "consisting essentially of" permits the
inclusion of substances that do not materially affect the basic and
novel characteristics of the composition under consideration.
* * * * *
References