U.S. patent application number 15/159055 was filed with the patent office on 2016-09-15 for overbased alkylated arylalkyl sulfonates.
The applicant listed for this patent is The Lubrizol Corporation. Invention is credited to Virginia A. Carrick, Ewan E. Delbridge, Christopher L. Friend, James P. Roski, Jonathan S. Vilardo, Gary M. Walker.
Application Number | 20160264904 15/159055 |
Document ID | / |
Family ID | 44021482 |
Filed Date | 2016-09-15 |
United States Patent
Application |
20160264904 |
Kind Code |
A1 |
Roski; James P. ; et
al. |
September 15, 2016 |
OVERBASED ALKYLATED ARYLALKYL SULFONATES
Abstract
An overbased alkylated arylalkyl sulfonate is easy to prepare
and is useful as a detergent in various lubricant applications.
Inventors: |
Roski; James P.; (Mentor,
OH) ; Delbridge; Ewan E.; (Concord Township, OH)
; Friend; Christopher L.; (Nottingham, GB) ;
Walker; Gary M.; (Allestree, GB) ; Carrick; Virginia
A.; (Chardon, OH) ; Vilardo; Jonathan S.;
(Chardon, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Lubrizol Corporation |
Wickliffe |
OH |
US |
|
|
Family ID: |
44021482 |
Appl. No.: |
15/159055 |
Filed: |
May 19, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13520260 |
Oct 8, 2012 |
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PCT/US2011/020736 |
Jan 11, 2011 |
|
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15159055 |
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61293732 |
Jan 11, 2010 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10N 2040/251 20200501;
C10M 2207/289 20130101; C10N 2050/10 20130101; C10N 2030/20
20130101; C10N 2040/045 20200501; C10M 2207/129 20130101; C10N
2030/04 20130101; C10N 2040/253 20200501; C10N 2040/255 20200501;
C10M 2215/064 20130101; C10M 135/10 20130101; C10M 2219/046
20130101; C10M 2215/28 20130101; C10N 2030/02 20130101; C10M
2219/106 20130101; C10N 2030/06 20130101; C10N 2040/08 20130101;
C10N 2040/252 20200501; C10N 2040/042 20200501; C10N 2030/18
20130101; C10N 2040/046 20200501; C10N 2040/04 20130101; C07C
309/24 20130101; C10M 2223/045 20130101; C10N 2040/24 20130101;
C10N 2030/45 20200501; C10N 2040/044 20200501; C10M 159/20
20130101; C10N 2030/52 20200501; C10N 2040/22 20130101; C10M
2219/046 20130101; C10N 2010/02 20130101; C10M 2219/046 20130101;
C10N 2010/04 20130101; C10M 2223/045 20130101; C10N 2010/04
20130101; C10M 2219/046 20130101; C10N 2010/02 20130101; C10M
2219/046 20130101; C10N 2010/04 20130101; C10M 2223/045 20130101;
C10N 2010/04 20130101 |
International
Class: |
C10M 135/10 20060101
C10M135/10 |
Claims
1. A lubricant composition comprising: an oil of lubricating
viscosity; and an overbased salt in an amount from about 0.3 to
about 8% by weight comprising: an anionic portion represented by
##STR00016## wherein each R.sup.1 is independently H or an alkyl
group of 1 to 4 carbon atoms; R.sup.2, R.sup.3, and R.sup.4 are
independently H or hydrocarbyl groups, R.sup.5 is a group
represented by
--CR.sup.1R.sup.7(CR.sup.1.sub.2).sub.oCHR.sup.1.sub.2, R.sup.6 is
H or --(CR.sup.1.sub.2).sub.mCHR.sup.1.sub.2, and R.sup.7 is H or
--(CR.sup.1.sub.2).sub.pCHR.sup.1.sub.2; m, n, o, and p are numbers
such that m+n is 4 to 28 and o+p is 3 to 27, provided that when
R.sup.6 is H, m is defined as 0 and n is 5 to 29 and when R.sup.7
is H, p is defined as 0 and o is 4 to 28; and wherein the total
number of carbon atoms in said anionic portion is at least 26; and
a metal or amine or ammonium cation; wherein the overbased salt has
a cation content in excess of that which would be present for
neutralization according to the stoichiometry of the cation and of
said anionic portion; and wherein the metal ratio of the overbased
salt is from about 1.1 to about 10.
2. The lubricating composition of claim 1, wherein the anionic
portion of the overbased salt is represented by ##STR00017##
wherein R.sup.5 is represented by
--CHR.sup.7(CH.sub.2).sub.oCH.sub.3 wherein R.sup.7 is H or
--(CH.sub.2).sub.pCH.sub.3 and o+p is 3 to 27.
3. The lubricating composition of claim 1, wherein the overbased
salt a TBN of about 10 to about 1100 on an oil-free basis.
4. The lubricating composition of claim 1 wherein the overbased
salt is a carbonated metal salt.
5. The lubricating composition of claim 1 wherein the cation of the
overbased salt comprises a calcium, magnesium, or sodium
cation.
6. The lubricating composition of claim 1 wherein the R.sup.1
groups in the SO.sub.3.sup.- containing substituent of the
overbased salt are H and n+m is about 8 to about 18
7. The lubricating composition of claim 1, wherein the R.sup.1
groups in R.sup.5 of the overbased salt are H and o+p is about 7 to
about 17.
8. The lubricant composition of claim 1 wherein one or two of
R.sup.2, R.sup.3, and R.sup.4 of the overbased salt are methyl
groups.
9. The lubricant composition of claim 1 wherein the anion portion
of the overbased salt comprises a species represented by
##STR00018## and isomers thereof, wherein q is 5 or 6 and R.sup.5
is a linear alkyl group containing 14 to 16 carbon atoms.
10. The lubricant composition of claim 1 wherein the overbased salt
comprises about 90 percent or more by weight of the total
detergents in the lubricant composition.
11. The lubricant composition of claim 1 further comprising at
least one dispersant, friction modifier, antiwear agent,
antioxidant, viscosity modifier, or additional overbased salt.
12. A method for lubricating a mechanical device, comprising
supplying thereto the lubricant composition of claim 1.
13. The method of claim 12 wherein the mechanical device comprises
an internal combustion engine, a transmission, a gear, or a
hydraulic system.
14. A method of preparing a lubricating composition comprising:
combining an oil of lubricating viscosity; and an overbased salt in
an amount of from about 0.3 to about 8 wt %, comprising a sulfonic
acid represented by ##STR00019## where n, m, o, p, R.sup.1,
R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are as defined in
claim 1, or a reactive equivalent thereof, with a stoichiometric
excess of a basic metal compound or amine compound or ammonia, the
overbased salt having a metal ratio of from about 1.1 to about
10.
15. The method of claim 14 wherein the sulfonic acid or reactive
equivalent thereof is reacted with an excess of calcium hydroxide,
calcium oxide, magnesium hydroxide, magnesium oxide, sodium
hydroxide, or sodium oxide.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No.
13/520,260 filed on Oct. 8, 2012 which claims priority from PCT
application Ser. No. PCT/US2011/020736 filed on Jan. 11, 2011 and
which claims benefit to Provisional Application Ser. No. 61/293,732
filed on Jan. 11, 2010.
BACKGROUND OF THE INVENTION
[0002] The disclosed technology relates to overbased alkylated
arylalkyl sulfonates that are useful as detergents in lubricant
applications.
[0003] U.S. Patent Publication 2009/0023950, Berger et al., Jan.
22, 2009, discloses polyalkylated arylalkyl sulfonic acids and
their salts. Such materials are reported to have the general
structure
##STR00001##
where R.sub.1, R.sub.2 and R.sub.3 are each separately and
independently H, alkyl (branched or linear C1 to C30),
R.sub.4.dbd.CH.sub.3(CH.sub.2).sub.oCH(CH.sub.2).sub.pCH.sub.3,
m+n=4 to 28, and o+p=3 to 27. The material is optionally
neutralized with a base such as sodium hydroxide, sodium carbonate,
potassium hydroxide, potassium carbonate, calcium hydroxide,
magnesium hydroxide, ammonium hydroxide, or amines.
[0004] U.S. Pat. No. 3,488,284, LeSuer et al., Jan. 6, 1970,
discloses basic metal complexes obtained by treating an oil-soluble
acid such as sulfonic acid with a metal base in the presence of an
acidic gas and an alcoholic promoter. The complexes are said to be
useful as detergent additives in fuels, oils and other organic
composition, and especially useful in lubricants. The oil-soluble
organic compound may be either aromatic, aliphatic, cycloaliphatic,
or arylaliphatic.
[0005] The disclosed technology, therefore, may solve one or more
of the problems encountered in lubricants and detergents for
lubricants, including providing one or more of good viscosity
performance, reduced coefficient of friction, improved wear
performance, improved soot-handling/dispersion performance,
improved fuel economy, improved engine durability, lighter color,
ease of preparation of an overbased sulfonate detergent, and
increased molecular weight without encountering properties of
waxiness. Good or improved performance may also be obtained in one
or more of deposit formation, foaming behavior, demulsification
behavior, and gelling properties.
SUMMARY OF THE INVENTION
[0006] The disclosed technology provides an overbased salt
comprising: [0007] an anionic portion represented by
##STR00002##
[0007] wherein each R.sup.1 is independently H or an alkyl group of
1 to 4 carbon atoms; R.sup.2, R.sup.3, and R.sup.4 are
independently H or hydrocarbyl groups, R.sup.5 is a group
represented by
--CR.sup.1R.sup.7(CR.sup.1.sub.2).sub.oCHR.sup.1.sub.2, R.sup.6 is
H or --(CR.sup.1.sub.2).sub.mCHR.sup.1.sub.2, and R.sup.7 is H or
--(CR.sup.1.sub.2).sub.pCHR.sup.1.sub.2; m, n, o, and p are numbers
such that m+n is 4 to 28 and o+p is 3 to 27, provided that when
R.sup.6 is H, m is defined as 0 and n is 5 to 29 and when R.sup.7
is H, p is defined as 0 and o is 4 to 28; and wherein the total
number of carbon atoms in said anionic portion is at least 26; and
a metal or amine or ammonium cation; wherein the overbased salt has
a cation content in excess of that which would be present for
neutralization according to the stoichiometry of the cation and of
said anionic portion.
[0008] The technology also provides a method of preparing an
overbased salt, comprising combining a sulfonic acid represented
by
##STR00003##
where n, m, o, p, R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, and
R.sup.6 are as defined as above, or a reactive equivalent thereof,
with a stoichiometric excess of a basic metal compound or amine
compound or ammonia and optionally reacting said mixture with
carbon dioxide. The ammonia may be supplied in the form of, e.g.,
ammonium hydroxide.
[0009] Further provided is a lubricant composition comprising an
oil of lubricating viscosity and the overbased salt described
above, as well as a method for lubricating a mechanical device,
comprising supplying thereto such a lubricant.
DETAILED DESCRIPTION OF THE INVENTION
[0010] Various preferred features and embodiments will be described
below by way of non-limiting illustration.
[0011] The present technology relates to an overbased salt as
described herein. 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 in general 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 or alternatively of another basic material
such as ammonia or an amine, and a promoter such as a phenol or
alcohol. 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 (if the neutralizing material is a basic 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. The term "metal ratio" may also be loosely
applied, by analogy, to materials which have an ammonium or amine
cation, rather than a metal cation.
[0012] Overbased detergents are often characterized by Total Base
Number (TBN). TBN is the amount of strong acid 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. Detergents which are useful in the present invention
typically have a TBN (oil-free basis) of 100 to 1100, and in one
embodiment 100 to 800, and in another 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.
[0013] The overall TBN of a lubricant 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 of a lubricant will typically be at
least 7 or at least 10, or sometimes even at least 20. Sulfated ash
(ASTM D-874) is another parameter often used to characterize such
compositions. Certain of the lubricant compositions of the present
technology 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%.
[0014] 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. Commonly used basic metal
compounds include calcium oxide and calcium hydroxide.
[0015] Overbased materials in general 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.
[0016] The overbased materials of the present invention, however,
are based on a sulfonic acid or reactive equivalent thereof which
has not hitherto been subjected to overbasing or to use in the
presently described applications or to obtain the presently
described advantages. The reactive equivalent of the sulfonic acid
may be an anhydride, ester, amide, salt, or other such compound
that can react with a basic compound to form an overbased salt. The
overbased materials of the present technology may be formed from
the polyalkylated arylalkyl sulfonic acids or their salts described
in US 2009/0023950.
[0017] The sulfonic acid used in the present technology (providing
the corresponding anionic group) may generally be represented by
the structure
##STR00004##
[0018] In this material, each of the R.sup.1 groups may
independently be hydrogen or an alkyl group of 1 to 4 carbon atoms,
alternatively 1 to 2 carbon atoms. In certain embodiments some or
all of the R.sup.1 groups are methyl, such as when the upper
substituent group and/or the R.sup.5 group are derived from
propylene. In other embodiments some or all of the R.sup.1 groups
are hydrogen, such as when one or both of the aforementioned groups
are derived from ethylene.
[0019] Groups R.sup.2, R.sup.3, and R.sup.4 are each independently
hydrogen or hydrocarbyl groups. The hydrocarbyl groups may each
contain 1 to 30 carbon atoms, or 1 to 18 or 1 to 6 or 1 or 2 carbon
atoms. The hydrocarbyl groups may be alkyl groups. They may be
linear or branched, and they may be saturated or unsaturated (e.g.,
alkylene) groups. In one embodiment, one or two of groups R.sup.2,
R.sup.3, and R.sup.4 are methyl groups. In one embodiment R.sup.2
and R.sup.3 are methyl groups and R.sup.4 is hydrogen. In one
embodiment the alkylated product is prepared from a xylene.
[0020] R.sup.5 is a group represented by
--CR.sup.1R.sup.7(CR.sup.1.sub.2).sub.oCHR.sup.1.sub.2 wherein
R.sup.7 is H or --(CR.sup.1.sub.2).sub.pCHR.sup.1.sub.2 and R.sup.1
is defined as above. Within the R.sup.5 group, o and p are numbers
such that o+p is 3 to 27 or 7 to 21 or 7 to 17 or 9 to 15 or 11 to
13, provided that when R.sup.7 is H, p is defined as 0 and each of
the above ranges of o +p is increased by 1. (That is, when R.sup.7
is H, not only is there no internal linking group
--CR.sup.1.sub.2--, but neither is there a carbon atom from the end
group CHR.sup.1.sub.2, but the total number of carbon atoms may be
unchanged) These ranges may also be appropriate when the R.sup.1
groups are H; when they are alkyl groups the total of o+p may be
reduced, if desired, by the number of carbon atoms provided by the
R.sup.1 groups within R.sup.5.
[0021] Thus, the total number of carbon atoms in the linear chain
of carbon atoms in R.sup.5 will typically be 6 to 30 or 10 to 24 or
12 to 18 or 14 to 16. When all the R.sup.1 groups within R.sup.5
are hydrogen, the R.sup.5 group is normally referred to as a
"linear" group, even though the point of attachment of the group to
the aromatic ring may not be at a terminal carbon. Such a R.sup.5
group may frequently be attached in the 2-position or the 3- (or
higher) position, resulting in a methyl or ethyl (or higher) branch
at the point of attachment. Attachment in the 1-position is also
possible, but it is believed that 2- or 3-attachment may be more
prominent. Thus a common representation of the attachment of a
linear R.sup.5 group to an aromatic ring may be as shown:
##STR00005##
A branched R.sup.5 group, in contrast, would have branches along
the chain, in addition to the nominal branch point at the position
of attachment.
[0022] In the structure above, R.sup.6 is H or
--(CR.sup.1.sub.2).sub.mCHR.sup.1.sub.2. In this regard, R.sup.6 is
similar to R.sup.7, described above. In the upper, SO.sub.3H
containing, substituent
##STR00006##
m and n are numbers such that m+n is 4 to 28 or 8 to 22 or 8 to 18
or 10 to 16 or 12 to 14, provided that when R.sup.6 is H, m is
defined as 0 and the values for m+n are increased by 1 from those
reported immediately above. (That is, when R.sup.6 is H, not only
is there no internal linking group --CR.sup.1.sub.2--, but neither
is there a carbon atom from the end group CHR.sup.1.sub.2, yet the
total number of carbon atoms may remain the same) These ranges are
also appropriate when the R.sup.1 groups are H; when they are alkyl
groups the total of m+n may be reduced, if desired, by the number
of carbon atoms provided by the R.sup.1 groups within the overall
substituent. Thus, the total number of carbon atoms in the linear
chain of carbon atoms in R.sup.6 will typically be 6 to 30 or 10 to
24 or 12 to 18 or 14 to 16. The discussion of "linear" in
connection with the R.sup.5 group is also applicable here, given
that the group may not be attached at the terminal carbon but may
nevertheless be considered to be linear.
[0023] The total number of carbon atoms in the sulfonic acid or the
resulting sulfonate, that is, in the anionic portion of the
overbased salt, should be at least 26 or at least 30 or at least
34, and may be up to an upper value which is not clearly defined
from a technical point of view but may, practically, be or 120 or
100 or 80 or 70 or 66. Suitable ranges include 30 to 60 or 34 to 50
or 36 to 40. The total number of carbon atoms includes the aromatic
carbon atoms, which, for a benzene ring is 6, so the number of
carbon atoms in the substituent groups would be, for instance, 6
less than the above numbers. It is believed that if the total
number of carbon atoms is below 26, sulfonic acid may not exhibit
sufficient oil-solubility to permit the overbasing process to
proceed smoothly, particularly when the medium in which the process
is conducted is oil.
[0024] In certain embodiments, the anionic portion of the overbased
material may be represented by the structure
##STR00007##
wherein R.sup.5 is represented by
--CHR.sup.7(CH.sub.2).sub.oCH.sub.3 and R.sup.7 is H or
--(CH2).sub.pCH.sub.3. More specific embodiments include species
that may be represented by
##STR00008##
and isomers thereof, wherein q is 5 or 6 and R.sup.5 is a linear
alkyl group containing 14 to 16 carbon atoms. Another exemplary
representation could be
##STR00009##
and positional isomers thereof (both in terms of location on the
benzene ring and position of attachment onto the carbon chains). It
is to be understood that a certain portion of the molecules may
comprise di-sulfonated or more highly sulfonated materials. For
instance, in some molecules (e.g., representing 0 to 10% or 0.5 to
5% or 1 to 4% of the mixture) each of the long-chain alkyl groups
may bear an SO.sub.3.sup.- group. Similarly, there may be present a
portion of dialkylated molecules without any SO.sub.3.sup.- group.
Synthesis of the arylalkyl sulfonic acid is described in greater
detail in U.S. Patent Publication 2009/0023950; see paragraphs 0025
through 0040.
[0025] The present overbased detergents may be prepared by methods
generally known for preparing overbased detergents, as described
above. More particularly, the appropriate sulfonic acid may be
first converted to a neutral salt by reaction with a basic compound
such as CaO, at room temperature or elevated temperature. The
neutral salt may be subsequently overbased; or the neutralization
and overbasing may occur in a single process.
[0026] The overbasing may include mixing of the neutral salt (or
the precursor sulfonic acid) with a stoichiometric excess of basic
compound (e.g., a basic metal compound such as calcium oxide or
calcium hydroxide, or alternatively compounds such as, magnesium
hydroxide, magnesium oxide, sodium hydroxide, or sodium oxide; or
alternatively a basic nitrogen compound such as ammonia or an
amine), typically in a solvent such as mineral oil, and typically
in the presence of one or more promoters such as alcohols. Typical
alcoholic promoters include mixtures of methanol, isobutyl alcohol,
and/or amyl alcohols, in various proportions. Optionally a small
amount of a dispersant (described below) or another detergent may
be present. The mixture is treated with an acidic gas, such as
typically CO.sub.2, which will convert at least a portion of the
excess basic compound to the salt, such as CaCO.sub.3. The addition
of the basic compound and the subsequent treatment with the acidic
gas may be conducted in several portions or iterations, which may
permit formation of materials with a higher metal ratio and total
base number. After the reaction is complete, volatile components
may be removed. The overbased materials may have metal ratios of
1.1 to 40, or 2 to 35, or 2.5 to 25, or 2.5 to 10, or 10 to 20 (or
corresponding analogous values if a non-metal basic compound is
used). The TBN of the products may be 10 to 1100 or 20 to 800 or 30
to 600 (calculated on an oil-free basis). The metal ion employed
may typically include calcium, magnesium, or sodium (i.e., a
calcium, magnesium, or sodium cation) or mixtures thereof, for
example, calcium.
[0027] One of the advantages of the present products is revealed in
their ease of preparation or stability characteristics. It is known
that conventional alkaryl sulfonates may exhibit a problem of
"skinning" during the overbasing process or upon storage
thereafter. This problem is identified, for instance, in U.S. Pat.
No. 6,054,410. Here it is disclosed that a superficial "skin" may
form, leading to high viscosity and low incorporation of calcium,
among other difficulties. This problem was addressed by restricting
the amount of aryl substitution on the 1 or 2 position of the
linear hydrocarbyl chain, or by using a selected mixture of alkyl
aryl sulfonates of super alkalinized (i.e., overbased) alkaline
earth metals, that is, effectively diluting the mixture with heavy
sulfonic acids. The materials of the present technology, however,
do not appear to exhibit this problem at all. The materials of the
present technology may also impart a measure of improvement, such
as anti-skinning performance, during overbasing or storage, or
other improvements. This may be observed when employed in
combination with other substrates, e.g., as cosubstrates in an
overbasing process, or when otherwise used in combination with
other sulfonate substrates or phenates or other such materials as
described hereinbelow in connection with the optional additional
detergents.
[0028] Amount of the overbased material described herein, within a
lubricant composition, will depend on the requirements of the
particular lubricant. However, it may generally be 0.01 to 5 or to
8 percent by weight, or alternatively 0.1 to 4 or 0.3 to 3.5% or
0.5 to 3% or 0.8 to 2.5% by weight.
[0029] The present materials are typically used in combination with
an oil of lubricating viscosity. The base oil used in the inventive
lubricating oil composition may be selected from any of the base
oils in Groups I-V as specified in the American Petroleum Institute
(API) Base Oil Interchangeability Guidelines. The five base oil
groups are as follows:
TABLE-US-00001 Viscosity Base Oil Category Sulfur (%) Saturates (%)
Index Group I >0.03 and/or <90 80 to 120 Group II
.ltoreq.0.03 and .gtoreq.90 80 to 120 Group III .ltoreq.0.03 and
.gtoreq.90 >120 Group IV All polyalphaolefins (PAOs) Group V All
others not included in Groups I, II, III or IV
Groups I, II and III are mineral oil base stocks. The oil of
lubricating viscosity, then, can include natural or synthetic
lubricating oils and mixtures thereof. Mixture of mineral oil and
synthetic oils, particularly polyalphaolefin oils and polyester
oils, are often used.
[0030] Natural oils include animal oils and vegetable oils (e.g.
castor oil, lard oil and other vegetable acid esters) as well as
mineral lubricating oils such as liquid petroleum oils and
solvent-treated or acid treated mineral lubricating oils of the
paraffinic, naphthenic or mixed paraffinic-naphthenic types.
Hydro-treated or hydrocracked oils are included within the scope of
useful oils of lubricating viscosity.
[0031] Oils of lubricating viscosity derived from coal or shale are
also useful. Synthetic lubricating oils include hydrocarbon oils
and halosubstituted hydrocarbon oils such as polymerized and
interpolymerized olefins and mixtures thereof, alkylbenzenes,
polyphenyl, (e.g., biphenyls, terphenyls, and alkylated
polyphenyls), alkylated diphenyl ethers and alkylated diphenyl
sulfides and their derivatives, analogs and homologues thereof.
Alkylene oxide polymers and interpolymers and derivatives thereof,
and those where terminal hydroxyl groups have been modified by, for
example, esterification or etherification, constitute other classes
of known synthetic lubricating oils that can be used. Another
suitable class of synthetic lubricating oils that can be used
comprises the esters of dicarboxylic acids and those made from C5
to C12 monocarboxylic acids and polyols or polyol ethers.
[0032] Other synthetic lubricating oils include liquid esters of
phosphorus-containing acids, polymeric tetrahydrofurans,
silicon-based oils such as the poly-alkyl-, polyaryl-, polyalkoxy-,
or polyaryloxy-siloxane oils, and silicate oils.
[0033] Hydrotreated naphthenic oils are also known and can be used.
Synthetic oils may be used, such as those produced by
Fischer-Tropsch reactions and typically may be hydroisomerised
Fischer-Tropsch hydrocarbons or waxes. In one embodiment oils may
be prepared by a Fischer-Tropsch gas-to-liquid synthetic procedure
as well as other gas-to-liquid oils.
[0034] Unrefined, refined and rerefined oils, either natural or
synthetic (as well as mixtures of two or more of any of these) of
the type disclosed hereinabove can used in the compositions of the
present invention. Unrefined oils are those obtained directly from
a natural or synthetic source without further purification
treatment. Refined oils are similar to the unrefined oils except
they have been further treated in one or more purification steps to
improve one or more properties. Rerefined oils are obtained by
processes similar to those used to obtain refined oils applied to
refined oils which have been already used in service. Such
rerefined oils often are additionally processed by techniques
directed to removal of spent additives and oil breakdown
products.
[0035] The amount of oil in a lubricant formulation may typically
be the amount which, when added to the other additives described
herein, gives 100 percent by weight. The amount in a fully
formulated lubricant may be 75 or 80 to 99 percent by weight, or 83
to 98 percent or 85 to 95 percent or 88 to 93 percent. If the oil
is present in a concentrate, the amount will be correspondingly
less. The amount of diluent oil that typically accompanies the
various additives will typically be counted as a part of the oil of
lubricating viscosity within the lubricant formulation.
[0036] Other additive components may also be present, in
conventional amounts as may be typical for the desired application.
Particularly noteworthy materials for lubricant applications are
described below.
[0037] One such component may be a detergent other than the
overbased alkylated arylalkyl sulfonates described herein.
Detergents in general and their methods of preparation are known
and have been described above, in the context of sulfonic acids
(sulfonates), carboxylic acids (carboxylates),
(hydrocarbyl-substituted) phenols (phenates), phosphonic acids
(phosphonates), and mixtures thereof.
[0038] Further examples of optional additional detergents include
an overbased saligenin detergent. Saligenin detergents are commonly
overbased magnesium salts, and they are based on saligenin
derivatives. A general example of a saligenin derivative can be
represented by the formula
##STR00010##
Here, X comprises --CHO or --CH.sub.2OH, Y comprises --CH.sub.2--
or --CH.sub.2OCH.sub.2--, and 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 such as Mg (that is to say,
in the case of a multivalent metal ion, one of the valences is
satisfied by the illustrated structure and other valences are
satisfied by other species such as anions, or by another instance
of the same structure), or mixtures thereof. 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. At least
one aromatic ring contains an R.sup.1 substituent and 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. 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).
[0039] Salixarate detergents are other examples of overbased
materials. They may be represented by a substantially linear
compound comprising at least one unit of formula (I) or formula
(II):
##STR00011##
each end of the compound having a terminal group of formula (III)
or (IV):
##STR00012##
such groups being linked by divalent bridging groups A, which may
be the same or different for each linkage. Here, R.sup.3 is
hydrogen or a hydrocarbyl group or a valence of a metal ion;
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. 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. The molecules on average will contain at least one of
unit (I) or (III) and at least one of unit (II) or (IV). 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-- and
--CH.sub.2OCH.sub.2--, either of which may be derived from
formaldehyde or a formaldehyde equivalent. 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."
[0040] The amount of any additional detergent, if present may be
0.01 to 4 or 0.1 to 3 or 0.5 to 2 weight percent in a fully
formulated lubricant. In one embodiment, there is no or
substantially no additional detergent present, beside the overbased
alkylated arylalkyl sulfonate described in detail above. In certain
embodiments the overbased alkylated arylalkyl sulfonate may
comprise 75% or more, or 90% or more, or 95% or more, or 98% or
more, by weight, of the total detergents, and in other embodiments
it may comprise 75% or more, or 90% or more, or 95% or more, or 98%
or more by weight of the sulfonate detergents in a composition. In
yet other embodiments, the overbased alkylated arylalkyl sulfonate
may be present in a smaller relative amount, such as 1 to 90% or 10
to 80% or 20 to 70% or 30 to 60% by weight of the total detergents,
the remainder being provided by one or more optional additional
detergents.
[0041] Dispersants are another type of additive. They are well
known in the field of lubricants and include primarily what is
known as ashless dispersants and polymeric dispersants. Ashless
dispersants are so-called because, as supplied, they do not contain
metal and thus do not normally contribute to sulfated ash when
added to a lubricant. However they may, of course, interact with
ambient metals once they are added to a lubricant which includes
metal-containing species. Ashless dispersants are characterized by
a polar group attached to a relatively high molecular weight
hydrocarbon chain. Typical ashless dispersants include
N-substituted long chain alkenyl succinimides, having a variety of
chemical structures including typically
##STR00013##
where each R.sup.1 is independently an alkyl group, frequently a
polyisobutylene group with a molecular weight (Mn) of 500-5000
based on the polyisobutylene precursor, 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. Also,
a variety of modes of linkage of the R.sup.1 groups onto the imide
structure are possible, including various cyclic linkages. The
ratio of the carbonyl groups of the acylating agent to the nitrogen
atoms of the amine may be 1:0.5 to 1:3, and in other instances 1:1
to 1:2.75 or 1:1.5 to 1:2.5. Succinimide dispersants are more fully
described in U.S. Pat. Nos. 4,234,435 and 3,172,892 and in EP
0355895.
[0042] It may also be desirable for some formulations that an
amount of a hydrocarbyl-substituted succinic anhydride such as
polyisobutene succinic anhydride (PIBSA) may be included, that is,
the material from which a succinimide dispersant is prepared, prior
to reaction with an amine.
[0043] Another class of ashless dispersant is high molecular weight
esters. These materials are similar to the above-described
succinimides except that they may be seen as having been prepared
by reaction of a hydrocarbyl acylating agent and a polyhydric
aliphatic alcohol such as glycerol, pentaerythritol, or sorbitol.
Such materials are described in more detail in U.S. Pat. No.
3,381,022.
[0044] Another class of ashless 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
##STR00014##
(including a variety of isomers and the like) and are described in
more detail in U.S. Pat. No. 3,634,515.
[0045] Other dispersants include polymeric dispersant additives,
which are generally hydrocarbon-based polymers which contain polar
functionality to impart dispersancy characteristics to the
polymer.
[0046] 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,
nitriles, epoxides, boron compounds, and phosphorus compounds.
References detailing such treatment are listed in U.S. Pat. No.
4,654,403.
[0047] The amount of any dispersant, if present may be 0.01 to 6 or
0.1 to 5 or 0.5 to 4 or 1 to 3 weight percent in a fully formulated
lubricant.
[0048] The lubricant may also contain a metal salt of a phosphorus
acid. Metal salts of the formula
[(R.sup.8O)(R.sup.9O)P(.dbd.S)--S].sub.n-M
where R.sup.8 and R.sup.9 are independently hydrocarbyl groups
containing 3 to 30 carbon atoms, are readily obtainable by heating
phosphorus pentasulfide (P.sub.2S.sub.5) and an alcohol or phenol
to form an O,O-dihydrocarbyl phosphorodithioic acid. The alcohol
which reacts to provide the R.sup.8 and R.sup.9 groups may be a
mixture of alcohols, for instance, a mixture of isopropanol and
4-methyl-2-pentanol, and in some embodiments a mixture of a
secondary alcohol and a primary alcohol, such as isopropanol and
2-ethylhexanol. The resulting acid may be 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 in many cases, zinc, to form zinc
dialkyldithiophosphates. Such materials are well known and readily
available to those skilled in the art of lubricant formulation.
Suitable variations to provide good phosphorus retention in an
engine are disclosed, for instance, in US published application
2008-0015129, see, e.g., claims.
[0049] The amount of a metal salt of a phosphorus acid, if present,
may be 0.01 to 4 or 0.1 to 3 or 0.5 to 2 weight percent in a fully
formulated lubricant.
[0050] Another component frequently used is a viscosity modifier.
Viscosity modifiers (VM) and dispersant viscosity modifiers (DVM)
are well known. Examples of VMs and DVMs may include
polymethacrylates, polyacrylates, polyolefins, styrene-maleic ester
copolymers, and similar polymeric substances including
homopolymers, copolymers and graft copolymers. The DVM may comprise
a nitrogen-containing methacrylate polymer and comprise units from
a nitrogen-containing methacrylate monomer, for example, a
nitrogen-containing methacrylate derived from methyl methacrylate
and dimethylaminopropyl amine, i.e., dimethylaminopropyl
methacrylamide.
[0051] Examples of commercially available VMs, DVMs and their
chemical types may include the following: polyisobutylenes (such as
Indopol.TM. from BP Amoco or Parapol.TM. from ExxonMobil); olefin
copolymers (such as Lubrizol.TM. 7060, 7065, and 7067 from Lubrizol
and Lucant.TM. HC-2000L and HC-600 from Mitsui); hydrogenated
styrene-diene copolymers (such as Shellvis.TM. 40 and 50, from
Shell and LZ.RTM. 7308, and 7318 from Lubrizol); styrene/maleate
copolymers, which are dispersant copolymers (such as LZ.RTM. 3702
and 3715 from Lubrizol); polymethacrylates, some of which have
dispersant properties (such as those in the Viscoplex.TM. series
from RohMax, the Hitec.TM. series from Afton, and LZ 7702.TM., LZ
7727.TM., LZ 7725.TM. and LZ 7720C.TM. from Lubrizol);
olefin-graft-polymethacrylate polymers (such as Viscoplex.TM. 2-500
and 2-600 from RohMax); and hydrogenated polyisoprene star polymers
(such as Shellvis.TM. 200 and 260, from Shell). Viscosity modifiers
that may be used are described in U.S. Pat. Nos. 5,157,088,
5,256,752 and 5,395,539. The VMs and/or DVMs may be used in the
functional fluid at a concentration of up to 20% by weight.
Concentrations of 1 to 12%, or 3 to 10% by weight may be used. The
amount of any additional detergent, if present may be 0.01 to 4 or
0.1 to 3 or 0.5 to 2 weight percent in a fully formulated
lubricant.
[0052] The amount of viscosity modifier and/or dispersant viscosity
modifier, if present may be 0.01 to 4 or 0.1 to 3 or 0.5 to 2
weight percent in a fully formulated lubricant.
[0053] Another component is an antioxidant. Antioxidants encompass
phenolic antioxidants, which may comprise a butyl substituted
phenol containing 2 or 3 t-butyl groups. The para position may also
be occupied by a hydrocarbyl group or a group bridging two aromatic
rings. The latter antioxidants are described in greater detail in
U.S. Pat. No. 6,559,105. Antioxidants also include aromatic amine,
such as nonylated diphenylamines. Other antioxidants include
sulfurized olefins, titanium compounds, and molybdenum compounds.
U.S. Pat. No. 4,285,822, for instance, discloses lubricating oil
compositions containing a molybdenum and sulfur containing
composition. Typical amounts of antioxidants will, of course,
depend on the specific antioxidant and its individual
effectiveness, but illustrative total amounts can be 0.01 to 5
percent by weight or 0.15 to 4.5 percent or 0.2 to 4 percent.
Additionally, more than one antioxidant may be present, and certain
combinations of these can be synergistic in their combined overall
effect.
[0054] Another additive is an antiwear agent. Examples of anti-wear
agents include phosphorus-containing antiwear/extreme pressure
agents such as metal thiophosphates, phosphoric acid esters and
salts thereof, phosphorus-containing carboxylic acids, esters,
ethers, and amides; and phosphites. In certain embodiments a
phosphorus antiwear agent may be present in an amount to deliver
0.01 to 0.2 or 0.015 to 0.15 or 0.02 to 0.1 or 0.025 to 0.08
percent phosphorus. Often the antiwear agent is a zinc
dialkyldithiophosphate (ZDP). For a typical ZDP, which may contain
11 percent P (calculated on an oil free basis), suitable amounts
may include 0.09 to 0.82 percent. Non-phosphorus-containing
anti-wear agents include borate esters (including borated
epoxides), dithiocarbamate compounds, molybdenum-containing
compounds, and sulfurized olefins.
[0055] Other types of antiwear agents include tartrate esters,
tartramides, and tartrimides, such as oleyl tartrimide, as well as
esters, amides, and imides of hydroxy-polycarboxylic acids in
general. These materials may also impart additional functionality
to a lubricant beyond antiwear performance. These materials are
described in greater detail in US Publication 2006-0079413 and U.S.
Provisional Application 61/120,932, filed 9 Dec. 2008.
[0056] The amount antiwear agent, if present may be 0.01 to 4 or
0.1 to 3 or 0.5 to 2 weight percent in a fully formulated
lubricant.
[0057] Other additives that may optionally be used in lubricating
oils include pour point depressing agents, extreme pressure agents,
color stabilizers and anti-foam agents.
[0058] Any of a variety of mechanical devices may be lubricated
with formulation containing the present overbased materials. Among
such devices are engines, including gasoline-fueled, diesel-fueled,
alcohol-fueled, bio-diesel-fueled, and hydrogen-fueled engines, as
well as hybrid engines and flexible-fueled engines. The engines may
be used in passenger cars, in heavy-duty diesel applications, both
on-road and off-road, marine diesel application, stationary gas
applications, and small engine applications, in both four cycle and
two-cycle engines. Other devices include transmissions, such as
manual transmissions and automatic transmissions including
continuously variable transmissions, traction drive systems, and
dual-clutch transmissions. They may also be used in the lubrication
of gears, in automotive and industrial applications, in hydraulic
systems, as components of greases for various applications, and in
metalworking fluids for metal forming or metal cutting.
[0059] The amount of each chemical component described is presented
exclusive of any solvent or diluent oil, which may be customarily
present in the commercial material, that is, on an active chemical
basis, unless otherwise indicated. However, 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.
[0060] 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: hydrocarbon substituents,
including aliphatic, alicyclic, and aromatic substituents;
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; and hetero substituents, that is, substituents which
similarly have a predominantly hydrocarbon character but contain
other than carbon in a ring or chain. A more detailed definition of
the term "hydrocarbyl substituent" or "hydrocarbyl group" is found
in paragraphs [0118] to [0119] of International Publication
WO2008147704 and paragraphs [0137] to [0141] of published
application US 2010-0197536.
[0061] 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.
EXAMPLES
[0062] The starting sulfonic acid used in the following examples is
a sulfonic acid provided by Champion Technologies, Inc., which is
believed to be approximately represented by, or to include species
that may be represented by, the general structure
##STR00015##
The material has a measured total acid number (TAN, mg KOH/g) of
110.5. It is believed that a small amount of material without the
R.sup.5 alkyl group is also present in the mixture.
Example 1
Substantially Neutral Salt Formation
[0063] To a 2 L flange flask is charged 600.0 g diluent mineral
oil, 69.2 g mixed isobutyl and amyl alcohols, 55.8 g polyisobutenyl
succinic anhydride, 60.0 g calcium hydroxide, 17.8 water, and 14.8
g acetic acid. The mixture is heated to 50.degree. C. and stirred
at 300 r.p.m. under nitrogen. At this time, 500 g of the arylalkyl
sulfonic acid is added dropwise at a rate to ensure that the
temperature of the mixture does not exceed 50.degree. C. After the
addition is complete, the mixture is heated to 100.degree. C. for 3
hours and then to 150.degree. C., at which temperature the majority
of the volatile solvent is removed by distillation. The product is
the substantially neutral calcium salt in diluent oil.
Example 2
60 TBN Overbased Calcium Detergent
[0064] 500.0 g of the neutral salt mixture from Ex. 1, 79.5 g of
mixed isobutyl and amyl alcohols, and 63.7 g methanol are heated,
with stirring, to 47.degree. C. At this temperature, 20.1 g calcium
hydroxide is charged and the mixture is stirred for 20 minutes.
Carbon dioxide gas, about 5.5 g, is blown through the mixture at
this temperature over 30 minutes. Thereafter, the reaction mixture
is heated to 150.degree. C. to remove volatile solvents and provide
a crude mixture with a solids level of 4%. The mixture is filtered
through Fax-5.TM. filter aid to give 451.0 g of the desired product
(87%), having an analysis of 3.5% calcium, 2.4% sulfur, 59.6 TBN
(total base number, as mg KOH/g), 11.7% sulfated ash, and KV100
(kinematic viscosity at 100.degree. C.) of 49.3 mm.sup.2/s
(cSt).
Example 3
290 TBN Overbased Calcium Detergent
[0065] 500.0 g of the neutral salt mixture from Ex. 1, 26.5 g mixed
isobutyl and amyl alcohols, 17.5 g calcium alkylphenate detergent
(containing 69% oil), and 52.3 g methanol are heated, with
stirring, to 47.degree. C. At this temperature, 34.0 g calcium
hydroxide is charged and the mixture is stirred for 20 minutes.
Carbon dioxide gas, about 1.01 g, is blown through the mixture at
this temperature over 30 minutes. A second addition of 34.0 g
calcium hydroxide is added and stirred for 20 minutes. An
additional amount of CO.sub.2 gas, about 20.3 g, is added over 55
minutes. At this point, 150.0 g toluene is added as a cosolvent. A
third portion of calcium hydroxide, 34.0 g, is added and the
mixture stirred for 20 minutes. Additional CO.sub.2, 20.3 g, is
added over 55 minutes. A fourth portion of calcium hydroxide, 34.0
g, is added and the mixture stirred for 20 minutes. Additional
CO.sub.2, 15.2 g, is added over 60 minutes. The reaction mixture is
heated to 150.degree. C. to remove the volatile solvents to provide
a crude mixture with solids content 4.2%. The mixture is filtered
through Fax-5.TM. filter aid to give 397.0 g of the desired product
(76%), having an analysis of 11.7% calcium, 2.0% sulfur, 290.2 TBN,
39.1% sulfated ash, and KV100 (kinematic viscosity at 100.degree.
C.) of 309.2 mm.sup.2/s (cSt).
[0066] A conventional engine lubricant formulation (except lacking
detergent) is prepared, containing, in mineral oil, the indicated
amounts in weight percent of the following components (each
reported including any diluent oil conventionally present):
TABLE-US-00002 Viscosity modifier 6 Dispersant viscosity modifier 2
Pour point depressant 0.2 Succinimide dispersant 8.2 Zinc dialkyl
dithiophosphate 1.09 Sulfur-containing antioxidant 0.38 Hindered
phenolic ester antioxidant 0.70 Aromatic amine antioxidant 0.15
Polybutene-succinic anhydride 0.10 Thiadiazole corrosion inhibitor
0.02 Antifoam agent 0.01
Example 4
Reference
[0067] Within the above lubricant formulation is included 1.95
percent of a conventional calcium overbased alkylbenzenesulfonate
detergent, 300 TBN, containing 42% diluent oil, 12.0% Ca, 40.8%
sulfated ash.
Example 5
[0068] Within the above lubricant formulation is included 1.95
percent of an overbased calcium detergent from an arylalkylsulfonic
acid salt, prepared similarly to that of Example 3, 300 TBN,
containing 41% diluent oil, 12% Ca, 40.8% sulfated ash.
[0069] The lubricant of reference Example 4 and of Example 5 are
subjected to the HFRR Ramp Test. This test method comprises a
reciprocating steel ball (6 mm) on flat steel disk geometry, with a
1000 .mu.m stroke, 20 Hz frequency and a temperature initially
maintained at 40.degree. C. for 15 minutes, then increased to
160.degree. C. at 2.degree. C. per minute. The applied load is 200
g. Viscosity properties of the blends and their performance in the
HFRR test are summarized in the following table.
TABLE-US-00003 Ex 4 (ref) Ex 5 (present Parameter conventional
technology) Viscosity at 40.degree. C. (mm.sup.2/s) 114.3 120.2
Viscosity at 100.degree. C. (mm.sup.2/s) 15.2 16.1 Viscosity Index
139 143 Viscosity at -20.degree. C. (cP) 6007 5831 HFRR Wear scar,
.mu.m (end of test) 211 200 HFRR Average % film thickness,
40-160.degree. C. 69 87 HFRR Avg. coeff. of friction,
40-160.degree. C. 0.140 0.137 HFRR Coefficient of friction,
40.degree. C. 0.116 0.102
[0070] The materials of the present technology impart better
viscosity performance to the test lubricant than does the
comparable reference detergent. They also provide a reduced
coefficient of friction and improved wear performance. These
performance advantages will contribute to improved fuel economy and
engine durability in an engine lubricating using the detergent of
the present technology.
[0071] The lubricants of reference Example 4 and of Example 5 are
further subjected to a soot suspension screening test, which
simulates the environment present in diesel engine sumps. The
sample lubricant is acidified with 1 vol. % of a 17.4 N mixture of
sulfuric acid and nitric acid, and to the mixture is added 6 wt %
of a modified carbon black and 5 wt % of a diesel fuel distillation
residue. This mixture is subjected to tissumization and sonication
to disperse the carbon black, then maintained at 90.degree. C. for
1 week while blown at 0.5 mL/min of 0.27% NO.sub.x in air. Soot
handling is evaluated daily by placing a 0.25 .mu.L aliquot of
sample onto chromatography paper and permitting the sample to
spread. The diameter of ratio of the diameter of the central carbon
spot to the total oil spot is presented as a percentage. Higher
percentages indicate greater efficiency of soot dispersion. The
central carbon spots are also rated microscopically for uniformity
of dispersion. Numerical ratings are assigned based on an
algorithm, wherein higher numbers indicate more uniform soot
(carbon) dispersion.
TABLE-US-00004 Ex 4 (ref) Ex 5 (present Parameter conventional
technology) Average spot ratio, % 63 71 Numerical spot rating,
average 1.6 2.5
[0072] The overbased salts of the disclosed technology may thus be
used to provide improved soot handling performance or improved
frictional performance to a lubricant
[0073] Each of the documents referred to above is incorporated
herein by reference. The mention of any document is not an
admission that such document qualifies as prior art or constitutes
the general knowledge of the skilled person in any jurisdiction.
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." 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.
* * * * *