U.S. patent number 3,620,977 [Application Number 04/784,462] was granted by the patent office on 1971-11-16 for reaction product of alkylene polyamines and chlorinated alkenyl succinic acid derivatives.
This patent grant is currently assigned to Chevron Research Company, San Francisco, CA. Invention is credited to Lewis R. Honnen, Nicolaas Bakker.
United States Patent |
3,620,977 |
|
November 16, 1971 |
REACTION PRODUCT OF ALKYLENE POLYAMINES AND CHLORINATED ALKENYL
SUCCINIC ACID DERIVATIVES
Abstract
Compositions are obtained by halogenating an alkenyl succinic
acid or acid derivative in a hydroxylic solvent and treating the
resulting product under dehydrating conditions with an amine. The
products with relatively long hydrocarbon chains find use as
detergents in lubricating oils and as emulsifiers. 13 Claims, No
Drawings
Inventors: |
Lewis R. Honnen (Petaluma,
CA), Nicolaas Bakker (Pinole, CA) |
Assignee: |
Chevron Research Company, San
Francisco, CA (N/A)
|
Family
ID: |
25132515 |
Appl.
No.: |
04/784,462 |
Filed: |
December 17, 1968 |
Current U.S.
Class: |
508/222;
548/546 |
Current CPC
Class: |
C10M
159/12 (20130101); C10M 133/52 (20130101); C10M
2219/046 (20130101); C10M 2223/045 (20130101); C10M
2209/103 (20130101); C10M 2215/26 (20130101); C10N
2010/04 (20130101); C10N 2070/02 (20200501); C10M
2209/10 (20130101); C10M 2207/32 (20130101); C10M
2215/28 (20130101); C10M 2217/046 (20130101); C10M
2227/02 (20130101); C10M 2209/02 (20130101); C10M
2203/00 (20130101); C10M 2223/04 (20130101); C10M
2209/00 (20130101); C10M 2223/047 (20130101); C10M
2217/06 (20130101); C10M 2223/042 (20130101); C10M
2219/044 (20130101); C10M 2205/02 (20130101); C10M
2207/04 (20130101); C10M 2215/04 (20130101); C10M
2203/10 (20130101); C10M 2215/08 (20130101); C10M
2215/082 (20130101); C10M 2215/086 (20130101) |
Current International
Class: |
C10M
133/52 (20060101); C10M 159/00 (20060101); C10M
159/12 (20060101); C10M 133/00 (20060101); C10m
001/32 (); 252 () |
Field of
Search: |
;260/268,326.5F,326.3,326.5FA |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Daniel E. Wyman
Assistant Examiner: W. J. Shine
Attorney, Agent or Firm: A. L. Snow F. E. Johnston B. I.
Rowland
Claims
1. A lubricating oil composition having an oil of lubricating
viscosity and from 0.1 to 10 weight percent of a detergent
composition prepared by reacting (A) an alkenyl succinic acid
compound of the formula: wherein R is an oil-solubilizing alkenyl
group of at least about 14 and up to about 300 carbon atoms having
alpha or beta ethylenic unsaturation, the X's are the same or
different and are hydroxyl or hydrocarbyloxy of from one to 12
carbon atoms, or may be taken together to form the oxy group of an
anhydride, with the proviso that when the X's are taken together to
form the oxy group, a hydroxylic solvent is employed, with (B) a
halogenating agent, wherein the halogen is of atomic number 17 or
35, introducing at least about one atom of halogen per succinyl
molecule to form the halogenated succinyl compound as a lactone
(C), contacting at a temperature in the range of from about
100.degree. to 225.degree. C., said lactone (C) with (D), wherein
(D) is ammonia, an aliphatic hydrocarbon amine other than tertiary
or alkylene polyamine of from two to 10 amine nitrogen atoms,
wherein the mole ratio of (D) to (C)
2. A lubricating oil composition according to claim 1 wherein (A)
is reacted with (B) at a temperature in the range of -10.degree. to
about
3. A lubricating oil composition according to claim 2 wherein the
halogen
4. A lubricating oil composition according to claim 1 wherein said
amine (D) is an alkylene polyamine of from two to six amine
nitrogen atoms and the alkylene group is from two to three carbon
atoms, there being at least two carbon atoms between the nitrogen
atoms; and R is polyisobutenyl of
5. A lubricating oil composition according to claim 4 wherein the
mole ratio of amine (D) to halogenated succinyl compound (C) is in
the range of
6. A lubricating oil composition according to claim 1 wherein R is
polyisobutenyl of from 50 to 200 carbon atoms, the halogen of said
halogenating agent is chlorine, the reaction of (A) and (B) is
carried out in the presence of an alkanol of from one to six carbon
atoms at a temperature in the range of -10.degree. to about
50.degree. C. to introduce from about one to 1.5 atoms of chlorine
per succinyl compound (A) and said amine is an alkylene polyamine
of the formula:
H(NHU).sub.n NH.sub.2 wherein U is alkylene of from two to three
carbon atoms, there being at least two carbon atoms between the
nitrogen atoms, and n is an integer of
Description
A significant breakthrough in the field of improved lubricating
oils was the advent of ashless detergents. These ashless detergents
were initially, for the most part, acyl derivatives of amines
having a relatively long hydrocarbon chain bonded to the acyl
group. Numerous patents have issued describing various ashless-type
lubricating oil detergents; see for example U.S. Pat. Nos.
3,219,666, 3,296,128, 3,200,075, 3,373,112, and 3,275,554.
While the above additives provide good sludge dispersancy, in many
instances their protection against varnish deposits is not as good.
Therefore, there have been continued efforts to find additives
which provide not only good sludge dispersancy but also minimize
varnish deposits.
The patents aforecited are, for the most part, illustrative of the
relevant prior art.
Compositions are prepared by halogenating an oil-soluble alkenyl
succinic acid or acid derivative, e.g. anhydride, monoester,
diester etc., and then treating the resulting halogenated product
with an amine to form an acyl and/or alkyl amine product which has
the amine compound in greater than a 1:1 mole ratio of amine to
acid compound. These materials are particularly useful as
lubricating oil detergents, providing protection from sludge and
varnish.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Product
The products which find use as lubricating oil detergents will
generally have weight average molecular weights of from about 700
to 10,000, more usually from about 1,000 to 6,000. In the molecule,
there will be at least 30 aliphatic carbon atoms and preferably at
least 50 aliphatic carbon atoms, usually not exceeding a total of
650 carbon atoms, more usually a total of 400 carbon atoms. There
will be at least one aliphatic hydrocarbon group of 14 carbon
atoms, preferably of at least 30 carbon atoms and usually not
exceeding 300 carbon atoms in length.
The compositions will generally have from 1 to 2 succinyl groups
per molecule, usually averaging at least 1 and between 1 and 2
succinyl groups. The succinyl includes lactone derivatives such as
paraconic acid.
The amines employed will provide at least 1.5 weight percent
nitrogen in the composition and generally not exceed 12 weight
percent nitrogen, more usually in the range of about 2 to 8 weight
percent nitrogen. Method of Preparation
In preparing the compositions, an alkenyl succinic acid or acid
derivative will initially be halogenated to introduce at least
about one atom of halogen per molecule of alkenyl succinic acid
compound. The alkenyl succinic acid compound will generally have
the following formula: Wherein R is an oil solubilizing alkenyl
group of at least about 14 and up to about 300 carbon atoms having
alpha or beta aliphatic unsaturation, more usually from about 30 to
250 carbon atoms and, preferably, from about 50 to 200 carbon
atoms; the two X's may be hydroxyl or hydrocarbyloxy of from one to
12 carbon atoms, more usually of from one to three carbon atoms, or
may be taken together to form an oxy (-O- ) group of an anhydride.
Preferably, the composition is a monoester or anhydride.
R, the alkenyl group, will normally be free of heteroatoms,
although up to about 5 weight percent of R may be present as
heteroatoms forming functional groups which do not interfere with
the process of preparation of the compositions of this invention or
their performance.
R will have olefinic unsaturation in the alpha or beta position to
the succinic moiety and be substantially free of other
unsaturation. R may be a straight or branched chain alkenyl group;
ordinarily, R will be a branched chain aliphatic group having on
the average about one side chain of from one to four carbon atoms
for every four carbon atoms along the longest chain; more usually,
the side chain will be from one to two carbon atoms and,
preferably, methyl. Preferably, R will be polypropylene or
polyisobutylene, although other oil-solubilizing alkyl groups may
be used.
When the succinic acid compound is a monoester or diester, any
hydroxylic hydrocarbon can be used to form the ester group, since
the hydrocarbyloxy radical X will normally be lost, for the most
part, during the preparation of the subject compositions. Usually,
X will conveniently be a lower alkoxy group of from one to three
carbon atoms, more usually X will be methoxy. The monoester may be
preprepared or be prepared in situ.
The halogen employed is either chlorine or bromine, (halogen of
atomic number 17 or 35 ) and preferably chlorine. Halogenating
agents may be used which will provide positive halogen under the
conditions of reaction, e.g., tert.-butyl hypochlorite.
The halogenation is carried out neat or in the presence of a
solvent. The halogenation is carried out under ionic conditions.
These conditions usually result in the addition of halogen across
the double bond. However, with the alkenyl succinic derivatives, it
is believed that only one halogen is added to the molecule at the
double-bond site and a lactone or other derivative is formed.
Various solvents may be used which do not interfere with the
halogenation of the alkenyl succinic acid. The solvents may be
aromatic hydrocarbons, aliphatic hydroxylic compounds or other
polar or nonpolar solvents, as well as mixtures. A preferred method
of halogenation is to halogenate the anhydride in the presence of a
hydroxylic solvent.
Illustrative hydroxylic solvents include water and alkanols of from
one to six carbon atoms, preferably alkanols of from one to two
carbon atoms, i.e., methanol and ethanol. In addition to the
hydroxylic solvent, an inert hydrocarbon or halohydrocarbon solvent
may be used. The preferred inert solvent is an aromatic hydrocarbon
such as benzene or tert.-butyl benzene, or an inert halohydrocarbon
such as chlorobenzene.
The temperature for the reaction will generally be from about
-10.degree. C. to about 100.degree. C., more usually from about
0.degree. C. to about 50.degree. C. The halogenation should be
carried out so as to minimize side reactions of the halogen.
The amounts of inert solvent and hydroxylic solvent may be varied
widely. Based on the alkenyl succinyl compound, the amount of inert
solvent may vary from 0.1 to about 2 parts of solvent per part of
succinyl compound. The hydroxylic solvent will usually vary from
about 0.01 to about 1 part per part of succinyl compound.
The halogenation will be continued until at least about one atom of
halogen is introduced per succinyl molecule and not more than about
two atoms, preferably from about one to 1.5 atoms. Of course, less
halogen may be introduced, but this will result in reduction of the
amount of desired product which is ultimately obtained. However, if
mixtures are desired of materials prepared in the prior art and the
compositions of this invention, reducing the amount of halogen
introduced to below one atom per succinyl molecule would directly
provide such mixtures.
When the reaction is complete, the volatile materials are removed
and the residue is ready to be used in the subsequent reaction.
Amines which find use are other than tertiary amines i.e. primary
and secondary amines, which may be monoamines or polyamines or
hydroxyalkyl or polyalkyleneoxy amines. Tertiary amines may be
present in combination with primary or secondary amines. The amines
may be ammonia or amines of from one to 30 carbon atoms, more
usually of from one to 20 carbon atoms having from one to 10 amine
nitrogen atoms and from one to 10 oxygen atoms, either hydroxylic
or ethereal. The amines will be free of other heteroatoms than
those designated. Usually, not more than three of the oxygen atoms
will be hydroxylic, more usually not more than two.
The alkylene polyamines will be of from two to 24 carbon atoms
having from two to 10 amine nitrogen atoms, preferably two to six
amine nitrogen atoms and alkylene groups of from two to six carbon
atoms, preferably two to three carbon atoms, there being at least
two carbon atoms between the nitrogen atoms. Also included in the
category of alkylene polyamines are piperazine derivatives and
aminoalkylene piperazine. The piperazine compositions frequently
accompany the alkylene polyamines, depending on the method of
preparation of the alkylene polyamines.
Commercially, alkylene polyamines are rarely individual compounds.
Usually one compound predominates and the composition has an
average composition that of the dominant compound. Therefore, when
referring to a specific alkylene polyamine, it is intended to
include such mixtures as substantially equivalent to the alkylene
polyamine named.
The alkylene polyamines will generally have the following
formula:
H(NHU).sub.n NH.sub.2 wherein U is alkylene of from 2 to 6, more
usually of from two to three carbon atoms, there being at least two
carbon atoms between the nitrogen atoms; and n is an integer of
from 2 to 10, more usually of from 2 to 6, generally averaging in
the range of 2 to 6 over the entire composition.
Illustrative alkylene polyamines include ethylene diamine,
propylene diamine, diethylene triamine, dipropylene triamine,
dihexamethylene triamine, triethylene tetramine, tetraethylene
pentamine, pentaethylene hexamine, nonaethylene decamine, etc.
Monoamines and diamines having at least one hydrocarbon group
bonded to only one nitrogen atom will have the following
formula:
H(NH--U.sup.1).sub.a NRR.sup.1 wherein U.sup.1 is alkylene of from
two to three carbon atoms, there being at least two carbon atoms
between the nitrogen atoms, R is a hydrocarbon group free of
aromatic unsaturation, having from 0 to 2 sites of ethylenic
unsaturation and is of from one to 20 carbon atoms, R.sup.1 is
hydrogen or a hydrocarbon group free of aromatic unsaturation
having from 0 to 2 sites of ethylenic unsaturation and of from one
to 20 carbon atoms and may be the same or different than R. a is 0
or 1.
The entire molecule will have from one to 24 carbon atoms, more
usually from four to 20 carbon atoms.
Illustrative compositions include dimethyl amine, propyl amine,
cyclohexylamine, N-hexyl propylene diamine, N-dodecyl propylene
diamine, N-hexadecyl propylene diamine, N-octadecenyl ethylene
diamine, N-octadecenyl propylene diamine, N,N-dimethyl propylene
diamine, etc.
The alkanol amines and polyalkyleneoxy amines have for the most
part the following formula: wherein m is an integer of from 0 to 2;
l is an integer of from 0 to 2; the sum of l and m is 2; p is an
integer of from 0 to 5; q and q.sup.1 are the number of AO units in
a chain pendant from nitrogen and each are in the range of 0 to 10,
the sum of q+ q.sup.1 being in the range of 1 to 10; r is an
integer of from 0 to 1; the sum of m and r is equal to or greater
than 1; s is an integer of from 0 to 1; and A is alkylene of from
two to three carbon atoms, there being at least two carbon atoms
between the heteroatoms.
The total number of AO units will be in the range of 1 to 10 , more
usually in the range of 1 to 6.
Illustrative alkanol amines include ethanol amine, diethanol amine,
N-hydroxyalkyl ethylene diamine, N-hydroxyethyl propylene diamine,
tetraethyleneoxy ethylene diamine, the reaction product of
tetraethylene pentamine and ethylene oxide in 1 to 5 mole ratio,
pentaethyleneoxy amine, and diethyleneoxy amine.
The reaction between the amine and the halogensuccinyl product may
be carried out neat or in an inert hydrocarbon solvent; or, in two
steps, first in solution and then neat. Inert solvents will usually
be hydrocarbons or acyl halides, generally having boiling points or
ranges in the range of 100.degree. C. to 175.degree. C.
Illustrative solvents include xylene, cumene, tert.-butylbenzene,
chlorobenzene etc.
The mole ratio of the amine to the halogenated-succinyl reaction
product will be at least 1:1, usually, about 1.5 to 10:1, and more
usually from about 2 to 7:1.
The concentration of the reactants will generally range from about
0.5 to 20 parts of total reactants per part of solvent, usually
from about 1 to 10 parts per part of solvent.
The reaction temperature will ordinarily be in the range of
100.degree. C. to 225.degree. C., more usually 110.degree. C. to
200.degree. C.
The time for the reaction will vary widely depending on the
temperature employed, the reactants, the size of the reaction
mixture and other variables.
When the reaction has come to completion, the reaction mixture may
be allowed to cool, which will usually result in a phase
separation. The organic layer may be separated from the amine salt
layer and worked up in any conventional manner. Usually the organic
layer will be freed of residual unreacted amine and purified by
extraction, chromatography, etc.
EXAMPLES
The following examples are offered by way of illustration and not
by way of limitation.
EXAMPLE 1
Into a reaction vessel was introduced 1,134 g. of polyisobutenyl
succinic anhydride (polyisobutenyl having a weight average
molecular weight of about 1,000), 500 ml. of benzene and 60 ml. of
water; chlorine was bubbled into the reaction mixture for 3 hours
(Flow Meter 1044B-Sapphire Ball Reading 5), followed by bubbling
nitrogen through the mixture for 1 hour. Benzene and water were
then removed in vacuo. Complete removal of the water was aided by
the addition of 300 ml. of benzene and azeotroping off the benzene
with nitrogen bubbling. An aliquot was taken and further stripped
in vacuo to provide a sample for analysis. Analysis: % Cl=
4.29.
To the above composition was added 500 g. of diethylene triamine
and 250 ml. of xylene. Any residual benzene was stripped and the
solution heated to 145.degree. C. Xylene and water were taken
overhead during a period of about 1 hour. The temperature was then
raised to 170.degree.-175.degree. C., distilling over any volatile
materials and the temperature maintained for 6 hours. After
allowing the mixture to stand and cool, the reaction mixture
separated into 2 layers. After decanting the liquid upper layer,
the bottom solid layer was washed with an aliphatic thinner and the
2 organic layers combined.
To the combined organic solutions was added 1 gallon of methanol;
the mixture was stirred, allowed to settle, and the supernatant
layer decanted. The precipitate was extracted with methanol,
followed by extraction with acetone and then redissolved with mixed
hexanes and reprecipitated with acetone. The precipitate was
dissolved in benzene to permit easy handling in preparing oil
solutions. Analysis: % N=2.54, 2.57; % Cl=0.20; molecular weight,
(ThermoNAM) 3113.
EXAMPLE 2
Into a reaction vessel was introduced 600 g. of polyisobutenyl
succinic anhydride (polyisobutenyl of about 1,000 weight average
molecular weight), 400 ml. of benzene and 50 ml. of methanol.
Chlorine was bubbled through the reaction mixture for 1.5 hours
(Flow Meter 1044B-Sapphire Ball Reading 5), followed by nitrogen
bubbling for one-half hour. Volatile materials were then removed in
vacuo, as the temperature was raised to a maximum bath temperature
of 95.degree. C. Analysis: % Cl=5.11.
To the residue was added 120 ml. of xylene and 250 g. of diethylene
triamine. The solution was then heated for 6 hours at
145.degree.-160.degree. C., taking off water and xylene overhead.
All volatile materials were then removed in vacuo to a final
temperature of 150.degree. C. After cooling the mixture, 300 ml. of
an aliphatic thinner was added, followed by the addition of 700 ml.
of a 50/50 by volume mixture of methanol and water. Upon stirring,
the mixture emulsified. To the solution was then added 1 gallon of
methanol and 400 ml. of water and the solution allowed to settle.
The liquid layer was decanted and the solid layer extracted with
aqueous methanol followed by extraction with acetone. An aliquot
was taken of the combined liquid layers and extracts and the
solvent removed in vacuo. Analysis: % N=3.33; % Cl=1.07, molecular
weight (ThermoNAM) 3578.
EXAMPLE 3
Into a reaction vessel was introduced 650 g. of polyisobutenyl
succinic anhydride (polyisobutenyl having about 1,000 weight
average molecular weight), 400 ml. of benzene and 50 ml. of
methanol. Chlorine was introduced at ambient temperatures for 1.75
hours (Flow Meter 1044B-Sapphire Ball Reading 5), followed by
nitrogen bubbling. Volatile materials were removed by slowly
reducing the pressure and raising the temperature to a final
pressure of 10 mm. Hg and a final bottoms temperature of
100.degree. C.
To the residue was added 200 ml. of xylene and 200 ml. of ethylene
diamine, and a mixture refluxed for 64 hours at about 110.degree.
C. After allowing the mixture to cool, 550 ml. of aliphatic thinner
were added and the solution filtered through Celite. To the
filtrate was added 800 ml. of water, 550 ml. of mixed hexanes and 1
gallon of methanol. The solution was allowed to settle, the layers
separated and the organic layer washed with aqueous methanol. The
organic layer was then filtered through Celite and the product
isolated. Analysis: % N=2.76; % Cl=1.06, molecular weight
(ThermoNAM) 2558.
EXAMPLE 4
Into a reaction flask was introduced 650 g. of polyisobutenyl
succinic anhydride (polyisobutenyl of about 1,000 weight average
molecular weight), 400 cc. benzene and 50 cc. of methanol. Chlorine
was bubbled through the reaction mixture for 4 hours (Flow Meter
1044 B-Sapphire Ball Reading at 3.5) followed by nitrogen for
one-half hour. The solvent was distilled in vacuo lowering the
pressure to 15 mm. Hg and raising the temperature to 115.degree. C.
The residue weighed 714 g. Analysis: % Cl, 5-5.5; Mol. wt.
(ThermoNAM), 1100.
A portion of the above product (0.59 mole) was combined with 250 g.
(2.42 moles) of diethylene triamine and heated at 160.degree. C.
for 7 hours in a nitrogen atmosphere. The reaction mixture was then
allowed to cool to 100.degree. C., when 850 cc. of an aliphatic
thinner was added, the mixture stirred, transferred to a separatory
funnel and the resulting two phases separated. The top layer was
filtered through Celite, stripped free of solvent and other
volatiles by heating to 155.degree. C. at 5 mm. Hg. The residue
weighed 680 g. Analysis: % N, 4.05, Mol. wt. (ThermoNAM) 4245.
EXAMPLE 5
Into a reaction vessel was introduced 650 gm. of polyisobutenyl
succinic anhydride (polyisobutenyl of about 1,000 weight average
molecular weight), 400 cc. of benzene and 50 cc. of methanol and
chlorine passed through the mixture for 1.75 hours (Flow Meter
1044B-Sapphire Ball Reading, 5-5.2). At the end of the
chlorination, nitrogen was bubbled through the mixture for 1 hour
and solvent distilled off in vacuo, the temperature being raised to
about 95.degree. C. The residue weighed 707 gm. Analysis: % Cl,
4.74.
The above procedure was repeated, the final product having 4.91
percent chlorine.
Each of the batches was diluted with 120 cc. of xylene and then 250
gm. diethylene triamine added to each batch. The two batches were
treated in a parallel manner as follows. The solution was
azeotroped for 6 hours at 160.degree. C., cooled to room
temperature, and decanted from the resulting salt layer. The salt
layer was washed with mixed hexanes, the hexanes evaporated and the
residue added to the decanted solution. An additional 250 gm.
diethylene triamine was charged and the mixture stirred at
105.degree. C. for 2 hours. After cooling to room temperature,
approximately 2l of an aliphatic thinner was used to dilute the
reaction mixture and the resulting mixture filtered through Celite
and solvent distilled off from the filtrate. The residue from the
first batch weighed 666 gm. and the residue from the second batch
weighed 630 gm.
Analysis: 1st, % N, 4.30, % Cl, 1.39, Mol. wt. (ThermoNAM), 2934;
2nd, % N, 4.20, % Cl 0.71, Mol. wt. (ThermoNAM) 2442.
LUBRICATING OILS
The compositions of this invention may be formulated with various
lubricating fluids (hereinafter referred to as oils) which are
either derived from natural or synthetic sources. Oils generally
have viscosities of from about 35 to 50,000 Saybolt Universal
Seconds (SUS) at 100.degree. F. Among natural hydrocarbonaceous
oils are paraffin-base, naphthenic-base, asphaltic-base and
mixed-base oils.
Illustrative of synthetic oils are: hydrocarbon oils such as
polymers of various olefins, generally of from two to eight carbon
atoms, and alkylated aromatic hydrocarbons; and nonhydrocarbon
oils, such as polyalkylene oxides, aromatic ethers, carboxylate
esters, phosphate esters, and silicon esters. The preferred media
are the hydrocarbonaceous media, both natural and synthetic.
The above oils may be used individually or together whenever
miscible or made so by the use of mutual solvents.
When the detergents of this invention are compounded with
lubricating oils for use in an engine, the detergents will be
present in at least about 0.1 weight percent and usually not more
than 20 weight percent, more usually in the range of about 1 to 10
weight percent. The compounds can be prepared as concentrates due
to their excellent compatibility with oils. As concentrates, the
compounds of this invention will generally range from about 10 to
70 weight percent, more usually from about 20 to 50 weight percent
of the total composition. Therefore, the detergents of this
invention will be found in lubricating oil compositions in amounts
of from about 0.1 to 70 weight percent.
A preferred aspect in using the compounds of this invention in
lubricating oils is to include in the oil from about 1 to 50
mM./kg. of a dihydrocarbyl phosphorodithioate, wherein the
hydrocarbyl groups are of from about four to 36 carbon atoms.
Usually, the hydrocarbyl groups will be alkyl or alkaryl groups.
The remaining valence of the phosphorodithioate will usually be
satisfied by zinc, but polyalkyleneoxy or a third hydrocarbyl group
may also be used. (Hydrocarbyl is an organic radical composed
solely of carbon and hydrogen which may be aliphatic, alicyclic,
aromatic or a combination thereof.)
Other additives may also be included in the oil such as pour point
depressants, oiliness agents, antioxidants, rust inhibitors, etc.
Usually, the total amount of these additives will range from about
0.1 to 10 weight percent, more usually from about 0.5 to 5 weight
percent. The individual additives may vary from about 0.01 to 5
weight percent of the composition.
In order to demonstrate the effectiveness of the subject
compositions on pistons for their effect on varnish, the exemplary
composition of example 2 was tested in what is referred to as a
Ford 6-Cylinder Varnish Engine Test. A highly compounded oil is
used, having the following formulation: 1.9 weight percent of
example 2, 50 mM./kg. of calcium as a calcium carbonate overbased
calcium mahogany sulfonate; and 15 mM./kg. of zinc, 0,0-dialkyl
phosphorodithioate (alkyl of from four to six carbon atoms). The
oil used is a mixture of SUNRAY DX 250 neutral oil and SUNRAY DX
150 bright stock in a 6.16:1 weight ratio.
The test is carried out with a six-Cylinder Ford engine having a
240 cu. in. displacement. The engine conditions are the same as the
cyclic conditions of the ASTM Sequence VB test. The engine
conditions are stressed by using a "dirty" fuel which is comprised
of 30 volume percent of FCC heavy cut having a boiling range of
from 253.degree. to 424.degree. F. with 70 percent of a commercial
regular grade gasoline. The fuel has 2 ml. per gallon of lead and
approximately 0.1 weight percent sulfur. The crankcase depression
is maintained at 1-inch water. The engine test is carried out for
60 hours.
When using the oil composition described above without any of the
subject composition, the piston varnish rating is 5.3 (based on
0-10, 10 being clean). With the subject additive, the rating is
7.3, a significant improvement.
The above test was repeated using 3 weight percent of a 50 weight
percent solution in Mid-Continent 100 neutral oil of the combined
compositions of example 5. The result for piston varnish was 8.0.
The results for total varnish and total sludge (on a basis of 0-50,
50 being clean) were 40.9 and 42.5, respectively.
The subject compositions were also tested for their effectiveness
as dispersants in maintaining sludge dispersed in oil and
preventing deposits in a 120-hour 1-G Caterpillar Test. The oil
used was a Mid-Continent SAE 30 oil, with 2.25 weight percent of
the exemplary composition of example 2, and 12 mM./kg. of zinc
di(alkylphenyl)phosphorodithioate. (The alkyl groups are
polypropylene of from about 12 to 15 carbon atoms.) The groove
deposit results are reported on a basis of 0-100, 100 being
completely full grooves. The land deposits are reported on the
basis of 0-800, 800 being completely black. When the above oil is
used without detergent, the groove deposits are 93- 15- 5- 2 and
the land deposits are 500- 800- 330. For the oil composition with
the detergent additive, the results are: for the grooves, 64- 0.8-
0.2- 0; for the lands, 60- 0- 10.
It is evident from the above results that the compositions of this
invention are effective not only in preventing varnish deposits,
but also in preventing deposits resulting from sludge. Therefore,
the subject compositions do not contribute by their own
decomposition to deposits, but remain stable for long periods of
time, while being capable of dispersing sludge and deposit-forming
intermediates in oil.
* * * * *