Note: Descriptions are shown in the official language in which they were submitted.
B4t~3
Bac~ground of the Invention
.
(1) Field of the Invention
This invention relates to lubricant compositions con- -
taining a major amount of an oil of lubricating viscosity
and a minor amount of at least one amino phenol whi~h are
useful in two-cycle internal combustion engines. More
particularly, it relates to such oils containing amino
phenols having at least one hydrocarbon-based group of at
least about 10 aliphatic carbon atoms. Since two-cycle
engine oils are often combined with fuels before or during
use, this invention also relates to two-cycle fuel-lubricant
mixtures.
(2) Prior Art
U.S. Patent 2,197,835 describes the formation of metal
salts of aromatic amines, said amines being formed by
nitration followed by reduction of wax-substituted hydroxy-
aromatic hydrocarbons. These metal salts can be incorpor- '
ated in mineral oils to depress their pour point and in-
crease their viscosity indices.
U.S. Patents 2,502,708 and 2,571,092 both disclose the
nitration and subsequent hydrogenation to an amine of
cardanol. This amino cardanol is said to be useful as an
anti-oxidant for mineral oils, fats and petroleum oils.
Cardanol, also known as anacardol, is also said to be a
mixture of 3-pentadecylphenol, 3-(8'-pentadecenyl)phenol, 3-
(8':11'-pentadecadienyl)phenol and 3-t8~ 14'-pentadecatri-
enyl)phenol. Formulae presented in both the '092 and '708
Patents as well as the chemical literature ~see the Diction-
ary of Organic Compounds, Vol. 1, Oxford University Press,
N.Y., 1965, page 229) show that the Cl 5 substituent in
cardanol is meta position to the hydroxy group.
-- 1 --
48
U.S. Patent 2,859,251 discloses the alkylation of
ortho-, para-, and meta-amino phenols with olefin polymers
having from 6 to 18 carbon atoms per molecule in the pre-
sence of a catalytic complex formed by mixing hydrogen
fluoride with boron trifluoride and an iron group metal
fluoride. The '251 patent fails to disclose whether the
alkyl groups in the product mixture are bonded to a carbon,
nitrogen and/or oxygen atom.
(3) General Background
Over the past several decades the use of spark-ignited
two-cycle ~two-stroke) internal combustion engines including
rotary engines such as those of the Wankel type has
steadily increased. They are presently found in power lawn
mowers and other power-operated garden equipment, power
chain saws, pumps, electrical generators, marine outboard
engines, snow mobiles and the like.
The increasing use of two-cycle engines coupled with
increasing severity of the conditions in which they have
operated has led to an increasing demand for oils to ade-
quately lubricate such engines. Among the problems asso-
ciated with lubrication of two-cycle engines are piston ring
sticking, rusting, lubrication failure of connecting rod and
main bearings and the general formation on the engine's
interior~ surfaces of carbon and varniæh deposits. The
~25~ formation of varnish is a particularly vexatious problem
since the build-up of varnish on piston and cylinder walls
is believed to ultimately result in ring sticking which
leads to failure of the sealing function o~ piston rings.
Such seal failure causes loss of cylinder compression which
is particularly damaging in two-cycle engines because they
~ r~d~ rK - 2 -
'
depend on suction to draw the new fuel char~e into the
exhausted cylinder. Thus, ring sticking can lead to de-
terioration in engine performance and unnecessary consump-
tion of fuel and/or lubricant. These additives can also
reduce spark plug fouling and engine port plugging problems.
The unique problems and techniques associated with the
lubrication of two-cycle engines has led to the recognition
by those skilled in the art of two-cycle engine lubricants
as a distinct lubricant type. See, for example, U.S. Patents
3,085,975, 3,004,837 and 3,753,905.
~he invention described herein 1s directed to alle-
viation of these problems through the provision of effective
additives for two-cycle engine oils and oil-fuel combina-
tions which eliminate or reduce engine varnish deposits and
; 15 piston ring seal failure.
~4) Objects
Therefore, it is an object of this invention to provide
novel lubricants and fuel-lubricant mixtures for two-cycle
engines.
It is a further object of this invention to provide
novel means for lubricating two-cycle engines.
Other objects will be apparent to those skilled in the
art upon review of the present specification.
S ~ Invention
~25 This invention comprises a lubricant composition for
two-cycle engines comprising a major amount by weight of at
r~ f~,o- cyc~ e/~qlr~
least oneAoil of lubric~ting viscosity and a minor amount by
weight of at least one amino phenol of the formula
(~H~c
(R3a Ar -~ tNH2)b Formula I
- 3 -
4~
wherein R is a su~stantially saturated hydrocarbon-based
substituent of at least about 30 aliphatic carbon atoms; a,b, and
c are each independently an integer of 1 up to three times
the number of aromatic nuclei present in Ar with the proviso
that the sum o~ a, b, and c does not exceed the unsatisfied
valences of Ar; and Ar is an aromatic moiety having 0 to 3
optional substituents selected from the group consisting of
lower alkyl, lower alkoxyl, nitro, halo, or combinations of
two or more of said optional suhstituents; with the proviso
that when Ar is a ~enzene nucleus having only one hydroxyl
and one R substituent, the R substituent is ortho or para to
said hydroxyl substituent~
The term "phenol" is used in this specification in its
art-accepted generic sense to refer to hydroxy-aromatic com-
pounds having at least one hydroxyl group bonded directly to
a carbon of an aromatic ring.
Lubricating oil-fuel mixtures for two-cycle engines and
methods for lubricating two~cycle engines including Wankel
engines are also within the scope of this invention.
The amino phenols used in the two-cycle oils of this
invention form no part of this invention but rather are the
invention of Richard M. Lange and are claimed by him in patent
application No. 263,210 filed by him the same day as this
application and assigned to the assignee of this application.
Description of the Invention
The Oils of Lubrica~ing Viscosity.
The two-cycle engine oil compositions of this invention
comprise a major amount of an oil of lubricating viscosi-ty.
.
1~6~4~
Typically this viscosity is in the range of about 2.0 to
about 150 cst at 98.9C., more typically in the range of
about 5.0 to about 130 cst at 98.9C.
These oils of lubricating viscosity can be natural or
synthetic oils. Mixtures of such oils are also often
useful.
Natural oils include animal oils and vegetable oils
(e.g., castor oil, lard oil) 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. Oils of
lubricating viscosity derived from coal or shale are also
useful base oils.
Synthetic lubricating oils include hydrocarbon oils and
halo-substituted hydrocarbon oils such as polymerized and
interpolymerized olefins (e.g., polybutylenes, polypro-
pylenes, propylene-isobutylene copolymers, chlorinated
polybutylenes, etc.); poly(l-hexenes), po}y(l-octenes),
poly(l-decenes), etc. and mixtures thereof: alkylbenzenes
20~ ~(e.g.,;dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes,
di-(2-ethylhexyl)-benzenes, etc.); polyphenyls (e.g.,
biphenyls, terphenyls, alkylated polyphenyls, etc.); alky-
lated diphenyl ethers and alkylated diphenyl sulfides and
;;the~derLvatives, ana}ogs and homologs thereof and the like.
25 ~ Oils made by polymerizing olefins of less than 5 carbon
atoms~,~ such as ethylene, propylene, butylenes, isobutene,
pentene,~and mixtures thereof are typical synthetic polymer
oils. Methods o preparing such polymer oils are well known
; to~those skilled in the art as is shown by U.S. Patents
~ - 5 -
;, :~
~, ~
2,278,445, 2,301,052, 2,318,719, 2,329,714, 2~345,574 and
2,422,443.
Alkylene oxide homopolymers and interpolymers and deri-
vatives thereof where the terminal hydroxyl groups have been
modified by esterification, etherification, etc. constitute
another class of known synthetic lubricating oils. These
are exemplified by the oils prepared through polymerization
of ethylene oxide or propylene oxide, the alkyl and aryl
ethers of these polyoxyalkylene polymers (e.g., methyl-
polyisopropylene glycol ether having an average molecular
weight of 1000, diphenyl ether of polyethylene glycol having
a molecular weight of 500-1000, diethyl ether of polypropy-
lene glycol having a molecular weight of 1000-1500, etc.) or
mono- and polycarboxylic esters thereof, for example, the
acetic acid esters, mixed C3-C8 fatty acid esters, or the
Cl 30Xo acid diester of tetraethylene glycol.
Another suitable class of synthetic lubricating oils
comprises the esters of dicarboxylic acids (e.g., phthalic
acid, succinic acid, alkyl succinic acids, alkenyl succinic
acids, maleic acid, azelaic acid, uberic acid, sebacic
acid, fumaric acid, adipic acid, linoleic acid dimer,
malonic acid, alkyl malonic acids, alkenyl malonic acids,
~ t
etc.) with a variety of alcohols (e.g., butyl alcohol, hexyl
alcohol, dodecyl alcohol~ 2-ethylhexyl alcohol, ethylene
glycol, diethylene glycol monoether, propylene glycol,
etc.). Specific examples of these esters include dibutyl
adipate, di(2-ethylhexyl)sebacate, di-n-hexyl fumarate,
dioctyl sebacate, diisooctyl azelate, dlisodecyl azelate,
dioctyl phthalate, didecyl phthalate, dieicosyl sebacate,
the 2-ethylhexyl diester of linoleic acid dimer, the complex
_
~ 6~
ester formed by reacting one mole of sebacic acid with two
moles of tetraethylene glycol and two moles of 2-ethyl-
hexanoic acid and the like.
Esters useful as synthetic oils also include those made
from Cs to Cl 2 monocarboxylic acids and polyols and polyol
ethers such as neopentyl glycol, trimethylol propane, pent-
aerythritol, dipentaerythritol, tripentaerythritol, etc.
Silicon-based oils such as the polyalkyl-, polyaryl-,
polyalkoxy-, or polyaryloxy-siloxane oils and silicate oils
comprise another useful class of synthetic lubricants (e.g.,
tetraethyl silicate, tetraisopropyl silicate, tetra-(2-
ethylhexyl~silicate, tetra-(4-methyl-hexyl)silicate, tetra-
(p-tert-butylphenyl)silicate, hexyl-(4-methyl-2-pentoxy)-
disiloxane, poly(methyl)siloxanes, poly(methylphenyl)siloxanes,
etc.). Other synthetic lubricating oils include liquid
esters of phosphorus-containing acids (e.g., tricresyl
phosphate, trioctyl phosphate, diethyl ester of decane
phosphonic acid, etc.), polymeric tetrahydrofurans and the
like.
Unrefined, refined and rerefined oil~, either natural
or synthetic (as well as mixtures of two or more of any of
these) of the type disclosed hereinabove can be used in the
lubricant compositions of the present invention. Unrefined
oils are those obtained directly from a natural or synthetic
source without further purification treatment. For example,
a shale oil obtained directly from retorting operations, a
petroleum oil o~tained directly from primary distillation or
ester oil obtained directly from an esterification process
and used without further treatment would be an unrefined
- 7
-
4~3
oil. 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. Many such puri-
fication techniques are known to those of skill in the art
such as solvent extraction, secondary distillation, acid or
base extraction, filtration, percolation, etc. 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 are also known
as reclaimed or reprocessed oils and often are additionally
processed by techniques directed to removal of spent addi-
tives and oil breakdown products.
- The Amino Phenols: The Aromatic Moiet , Ar.
. . . ~
The aromatic moiety, Ar, can be a single aromatic
nucleus such as a benzene nucleus, a pyridine nucleus, a
thiophene nucleus, a 1,2,3,4-tetrahydronaphthalene nucleus,
etc., or a polynuclear aromatic moiety. Such polynuclear
moieties can be of the fused type; that is, wherein at least
two aromatic nuclei are fused at two points to another
nucleus such as found in naphthalene, anthracene, the
azanaphthalenes, etc. Such polynuclear aromatic moieties
also can be of the linked type wherein at least two nuclei
teither mono or polynuclear) are linked through bridging
linkages to each other. Such bridging linkages can be
chosen from the group consisting of carbon-to-carbon single
bonds, ether linkages, keto linkages, sulfide linkages,
polysulfide linkages of 2 to 6 sulfur atoms, sulfinyl
linkages, sulfonyl linkages, methylene linkages, alkylene
linkages, di-(lower alkyl)methylene linkages, lower alkylene
ether linkages, alkylene keto linkages, lower alkylene
- 8 -
48
sulfur linkages, lower alkylene polysulfide linkages of 2 to
6 carbon atoms, amino linkages, polyamino linkages and
mixtures of such divalent bridging linkages. In certain
instances, more than one bridging linkage can be present in
Ar between aromatic nuclei. For example, a fluorine nucleus
has two benzene nuclei linked by both a methylene linkage
and a covalent bond. Such a nucleus may be considered to
have 3 nuclei but only two of them are aromatic. Normally,
Ar will contain only carbon atoms in the aromatic nuclei per
se.
The number of aromatic nuclei, fused, linked or both,
in Ar can play a role in determining the values of a, b and
c in Formula I. For example, when Ar contains a single
aromatic nucleus, a, b and c are each independently 1 to
3. When Ar contains 2 aromatic nuclei, a, b and c can each
be an integer of 1 to 6 that is, from 1 up to three times
the number of aromatic nuclei present (e.g., in naphthalene,
2 nuclei). With a trinuclear Ar moiety, a, b and c can
again each be an integer of 1 to 9. Thus, for example, when
Ar is a biphenyl moiety, a, b and c can each independently
be an integer of 1 to 6. The values of a, b and c are
obviously limited by the fact that their sum cannot exceed
the total unsatisfied valences of Ar.
The single ring aromatic nucleus which can be the Ar
moiety can be represented by the general formula
ar(Q)m
wherein ar represents a single ring aromatic nucleus (e.g.,
benzene) of 4 to 10 carbons, each Q independently represents
a lower alkyl group, lower alXoxyl group, nitro group, or
48
halogen atom, and m is O to 3. As used in this specifi-
cation and appended claims, "lower" refers to groups having
7 or less carbon atoms such as lower alky~ and lower alkoxyl
groups. Halogen atoms include fluorine, chlorine, bromine
and iodine atoms; usually, the halogen atoms are fluorine
and chlorine atoms.
Specific examples of such single ring Ar moieties are
the following:
H~CH H~H H~H
~ ~ ~
H~Me Hl~c Cl H ~H
H
etc .
-- 10 --
-
1 ~Q ~ ~4 ~
wherein Me is methyl, Et is ethyl, Pr is n-propyl, and Nit
is nitro.
When Ar is a polynuclear fused-ring aromatic moiety, it
can be represented by the general formula
ar ~ ar ~m' (Q)mm
wherein ar, Q and m are as defined hereinabove, m' is 1 to
4 and ~ represent a pair of fusing bondR fusing ~wo rings
so as to make two carbon atoms part of the rings of each of
two adjacent rings. Specific examples of fused ring aro-
matic moieties Ar are:
H ~ H H ~
H ~ H H ~ -H
Mer~ Me Mler ~ ~ Ni.
H ~ H H ~ H
H H
UeO
H
H
etc.
15 ~:When the aromatic moiety Ar iQ a linked polynuclear
aromatic moiety it can be represented by the general formula
ar~Lng-ar~w (Q)mw
wherein W iS an integer of 1 to about 20, ar is as described
above with the proviso that there are at least 3 unsatisfied
20(i.e., free) valences in the total of ar groups, Q and m are
11 --
, .
348
as defined hereinbefore, and each Lng is a bridging linkage
individually chosen from the group consisting of carbon-to-
carbon single bonds, ether linkages (e.g., -o-)~ keto link-
ages (e.g., -C-), sulfide linkages (e.g., -S-), polysulfide
linkages of 2 to 6 sulfur linkages (e.g., -S2-6-), sulfinyl
linkages (e.g., -S(O)-), sulfonyl linkages (e.g., -S(O) 2-)
lower alkylene linkages (e.g., -CH2-, -CH2-CH2-, -CH-7H-,
R
etc.), di(lower alkyl)-methylene linkages (e.g., -CR~-),
lower alkylene ether linkages (e.g., -CH20-, -CH20-CH2-,
-CH2-CH20-, -CH2CH20CH2CH2-, -CH2lHOCH2fH-, -CH2fHOfHCH2-,
R R R R~
et~.), lower alkylene keto linkages ~e.g., -CN2C-,
-CH2CCH2-), lower alkylene sulfide linkages (e.g., wherein
one or more -O-'s in the lower alkylene ether linkages is
replaced with an -S- atom), lower alkylene polysulfide
linkages (e.g., wherein one or more -O-'s is replaced with
a -S2-6 group), amino linkages (e.g., -N-, -N-, -CH2N-,
1 R~ I
-CH2lNCH2-, -alk-l-, where alk is lower alkylene, etc.),
polyamino linkages ~e.g., -~(alk~ O, where the unsatis-
fied free N valences are taken up with H atoms or R groups),
and mixtures of such bridging linkages (each R being a
lower alkyl group).
Specific examples o~ Ar when it is a linked polynuclear
aromatic moiety include:
- 12 -
4~
"~ u ~L
~ CH 2 ~N
H2
_ 'M
i; J,1~,,,o
~:~ H Me H
H: H
H ~-,0 ,etc.
UsualIy all these Ar moieties are un0ubstituted except
:~ ~ for the R, -OH and -NH2 groups ~and any bridging groups).
For such reasons as cost, availability, performance,
}O etc., the Ar moiety is normally a benzene nucleus, lower
- 13 -
348
alkylene bridged benzene nucleus, or a napthalene nucleus.
Thus, a typical Ar moiety is a benzene or napthalene nucleus
having 3 to 5 unsatisfied valences, so that one or two of
said valences may be satisfied by a hydroxyl group with the
remaining unsatisfied valences being, insofar as possible,
either ortho or para to a hydroxyl group. Preferably, Ar is
a benzene nucleus having 3 to 4 unsatisfied valences so that
one can be satisfied by a hydroxyl group with the remaining
2 or 3 being either ortho or para to the hydroxyl group.
The Substantiall Saturated H drocarbon-based Group R.
. Y . ..~
The amino phenols used in the two-cycle oils of the
present invention contain, directly bonded to the aromatic
moiety Ar, a substantially saturated monovalent hydrocarbon-
based group R of at least about 30 aliphatic carbon atoms.
This R group can have up to a~out ~00 aliphatic carbon atoms.
More than one such group can be present, but usually, no more
than 2 or 3 such groups are present for each aromatic nucleus
in the aromatic moiety Ar. The total number of R groups
present is indicated by the value for "a" in Formula I. More
typically, the hydrocarbon-based group has at least about 50
aliphatic carbon atoms and up to about 400 t more typically, up
to about 300 aliphatic carbon atoms.
Generally, the hydrocarbon-based groups R are made
from homo- or interpolymers (e.g., copolymers, terpolymers) of
mono- and di-olefins having 2 to lO carbon atoms, such as
ethylene, propylene, butene-l, isobutene, butadiene, isoprene,
l-hexane, l-octene, etc. Typically, these olefins are
l-monoolefins. The R groups can also be derived from
~` - 14 -
.,,~,,
1~9~48
the halogenated (e.g., chlorinated or brominated) analogs of
such homo- or interpolymers. The R groups can, however, be
made from other sources, such as monomeric high molecular
weight alkenes (e.g., l-tetracontene) and chlorinated
analogs and hydrochlorinated analogs thereof, aliphatic
petroleum fractions, particularly paraffin waxes and cracked
and chlorinated analogs and hydrochlorinated analogs there-
of, white oils, synthetic alkenes such as those produced by
the Ziegler-Natta process (e.g., poly(ethylene) greases) and
other sources known to those skilled in the art. Any un-
saturation in the R groups may be reduced or eliminated by
hydrogenation according to procedures known in the art
before the nitration step described hereafter.
As used herein, the term "hydrocarbon-based" denotes a
group having a carbon atom directly attached to the re-
; mainder of the molecule and having a predominantly hydro-
carbon character within the context of this invention.
Therefore, hydrocarbon-based groups can contain up to one
; non-hydrocarbon radical for every ten carbon atoms provided
this non-hydrocarbon radical does not significantly alter
the predominantly hydrocarbon character of the group. Those
skilled in the art will be aware of such radicals, which
include, for example, hydroxyl, halo (especially chloro and
fluoro), alkoxyl, alkyl mercapto, alkyl sulfoxy, etc.
Usually, however, the hydxocarbon-based groups R are purely
hydrocarbyl and contain no such non-hydrocarbyl radicals.
The hydrocarbon-based groups R are substantially sat-
urated, that is, they contain no more than one carbon-to-
carbon unsaturated bond for every ten carbon-to-carbon
single bonds present. Usually, they contain no more than
- 15 -
1096~48
one carbon-to-carbon non-aromatic unsaturated bond for every
50 carbon-to-carbon bonds present.
The hydrocarbon-based groups of the amino phenols used
in the two-cycle oils of this invention are also substan-
tially aliphatic in nature, that is, they contain no more
than one non-aliphatic moiety (cycloalkyl, cycloalkenyl or
aromatic) group of six or less carbon atoms for every ten
carbon atoms in the R group. Usually, however, the R groups
contain no more than one such non-aliphatic group for every
fifty carbon atoms, and in many cases, they contain no such
non-aliphatic groups at all; that is, the typical R groups
are purely aliphatic. Typically~ these purely aliphatic R
groups are alkyl or alkenyl groups.
Specific examples of the substantially saturated
hydrocarbon-based R groups are the following:
a tetra(propylene) group
a tri~isobutene) group
a tetracontanyl group
a henpentacontanyl group
a mixture of poly(ethylene/propylene) groups of
about 35 to about 70 carbon atoms
a mixture of the oxidatively or mechanically
degraded poly(ethylene/propylene) groups of about
35 to about 70 carbon atoms
a mixture of poly(propylene/l~hexene) groups of
about 80 to about 150 carbon atoms
a mixture of poly (isobutene) groups having between
20 and 32 carbon atoms
a mixture of poly(isobutene) groups having an
average of 50 to 75 carbon atoms
- 16 -
.. . .
~ ' : ' . ' ' , .. . .
4~
A preferred source of the group R are poly(isobutene)s
obtained by polymerization of a C4 refinery stream having a
butene content of 35 to 75 weight percent and isobutene
content of 30 to 60 weight percent in the presence of a
Lewis acid catalyst such as aluminum trichloride or boron
trifluoride. These poly~utenes contain predominantly
(greater than 80~ of total repeating units) isobutene
repeating units of the configuration
fH3
- CH2--C ---
1H 3
The attachment of the hydrocarbon-based group R to the
aromatic moiety Ar of the amino phenols used in the two-
cycle oils of this invention can be accomplished by a numb~r
of techniques well known to those skilled in the art. One
particularly suitable technique is the Friedel-Crafts reac-
tion, wherein an olefin (e.g., a polymer containing an
olefinic bond), or halogenated or hydrohalogenated analog
thereof, is reacted with a phenol. The reaction occurs in
the presence of a Lewis acid catalyst (e.g., boron tri-
~ fluoride and its complexes with ethers, phenols, hydrogen
fluoride, etc., aluminum chloride, aluminum bromide, zinc
dichloride, etc.). Methods and conditions for carrying out
such reactions are well known to those skilled in the art.
See, for example, the discussion in the article entitled,
"Alkylation of Phenols" in Kirk Othmer "Encyclopedia of
2~5 Chemical Technology", Second Edition, Vol. 1, pages 894-895,
` ~ Interscience Publishers, a division of John Wiley and Company,
; N.Y., 1963. Other equally well known appropriate and
convenient techniques for attaching the hydrocarbon-based
group R to the aromatic moiety Ar will occur readily to
those skilled in the art.
- 17 -
~6~4~
As will be appreciated from inspection of Formula I,the
amino phenols used in the two-cycle oils of this invention
contain at least one of each of the following substituents:
a hydroxyl group, a R group as defined above, and a primary
amine group, -NH2. Each of the foregoing groups must be
attached to a carbon atom which is a part of an aromatic
nucleus in the Ar moiety. They need not, however, each be
attached to the same aromatic ring if more than one aromatic
nucleus is present in the Ar moiety.
In a preferred embodiment, the amino phenols used in
the two-cycle oils of this invention contain one each of the
foregoing substituents and but a single aromatic ring, most
preferably benzene. This preferred class of amino phenols
can be represented by the formula
T
~ NH2
~R''')z
wherein the R' group is a hydrocarbon-based group of about
30 to about 400 aliphatic carbon atoms located ortho or para
to the hydroxyl group, R''' is a lower alkyl, lower alkoxyl,
nitro group or halogen atom and z is 0 or 1. Usually z is 0
and R' is a substantially saturated, purely aliphatic gropp.
Often it is an alkyl or alkenyl group para to the -OH sub-
~stituent.
In a still more preferred embodiment of this invention,
the amino phenol is of the formula
OH
~ ~ NH2
; 25 (R''')
R~
~ "
~ - 18 -
48
wherein R" is derived from homopolymerized or interpoly-
merized C2-~0 l-olefins and has an average of from about 30
to about 300 aliphatic carbon atoms and R" ' and z are as
defined above. Usually R" is derived from ethylene, pro-
pylene, butylene and mixtures thereof. Typically, it is
derived from polymerized isobutene. Often R" has at least
about 50 aliphatic carbon atoms and z is 0.
The amino phenols used in the two-cycle oils of the
present invention can be prepared by a number of snythetic
routes. These routes can vary in the type reactions used
and the sequence in which they are employed. For example,
an aromatic hydrocarbon, such as benzene, can be alkylated
with alkylating agent such as polymeric olefin to form an
alkylated aromatic intermediate. This intermediate can then
be nitrated, for example, to form polynitro intermediate.
The polynitro intermediate can, in turn, be reduced to a
diamine, which can then be diazotized and reacted with water
to convert one of the amino groups into a hydroxyl group and
provide the desired amino phenol. Alternatively, one of the
nitro groups in the polynitro intermediate can be converted
to a hydroxyl group through fusion with caustic to provide a
hydroxy-nitro alkylated aromatic which can then be reduced
to provide the desired amino phenol.
; Another useful route to amino phenols involves the
alkylation of a phenol withan olefinic alkylating agent to
form an alkylated phenol. This alkylated phenol can then be
nitrated to form a mono- or polynitro phenol which can be
converted to the desired amino phenols by reducing at least
a portion of the nitro groups in the intermediate to amino
-- 19 --
1~9~
groups.
Techniques for alkylating phenols are well known to
those skilled in the art as the above-noted article in Kirk-
Othmer "Encyclopedia of Chemical Technology" demonstrates.
Techniques for nitrating phenols are also known. See, for
example, in Kirk-Qthmer "Encyclopedia of Chemical Techno-
logy", Second Edîtion, Vol. 13, the article entitled "Nitro-
phenols", page 888 et seq., as well as the treatises "Aromatic
Substitution; Nitration and Halogenation" by P. B. D. De La
Mare and J. H. Ridd, N.Y., Academic Press, 1959; "Nitration
and Aromatic Reactivity" by J. G. Hogget, London, Cambridge
University Press, 1961; and "The Chemistry of the Nitro and
Nitroso Groups", Henry Feuer, Editor, Interscience Pub-
lishers, N.Y., 1969.
Aromatic hydroxy compounds can be nitrated with nitric
acid, mixtures of nitric acid with acids such as sulfuric
acid or boron trifluoride, nitrogen tetraoxide, nitronium
tetrafluoroborates and acyl nitrates. Generally, nitric
acid of a concentration of, for example, about 60-90% is a
convenient nitrating reagent. Substantially inert liquid
diluents and solvents such as acetic or butyric acid can aid
in carrying out the reaction by improving reagent contact.
Conditions and concentrations for nitrating hydroxy
aromatic compounds are also well known in the art. For
example, the reaction can be carried out at temperatures of
about -15C. to about 150Co Usually nitration is con-
veniently carried out between about 25-75C.
Generally, depending on the particular nitrating agent
about 0.5-4 moles of nitrating agent is used for every mole
of aromatic nucleus present in the hydroxy aromat~c inter-
- 20 -
4~
mediate to be nitrated. If more than one aromatic nucleus is
present in the Ar moiety, the amount of nitrating agent can
be increased proportionately according to the number of such
nuclei present. For example, a mole of naphthalene-based
aromatic intermediate has, for purposes of this invention,
the equivalent of two "single ring" aromatic nuclei so that
about 1-4 moles of nitrating agent would generally be used.
When nitric acid is used as a nitrating agent usually about
l.O to about 3.0 moles per mole of aromatic nucleus is used.
Up to about a 5 molar excess of nitrating agent (per "single
ring" aromatic nucleus) may be used when it is desired to
drive the reaction forward or carry it out rapidly.
Nitration of a hydroxy aromatic intermediate generally
takes 0.25 to 24 hours depending on such variables as
temperature, the amount, type and quality of intermediate
and nitrating agent~ though it may be convenient to react
the nitration mixture for longer periods, such as 96 hours.
Reduction of aromatic nitro compounds to the corres-
ponding amines is also well known. See, for example, the
article entitled "Amination by Reduction" in Kirk-Othmer
"Encyclopedia of Chemical Technology", Second Edition, Vol.
2, pages 76-99. Generally, such reductions can be carried
out with, for example, hydrogen, carbon monoxide or hydra-
zine, (or mixtures of same) in the presence of metallic
catalysts such as palladium, platinum and its oxides,
nickel, copper chromite, etc. Co-catalysts such as alkali
or alkaline earth metal hydroxides or amines (including
-~ amino phenols) can be used in these catalyzed reductions.
Reduction can also be accomplished through the use of
~30 reducing metals in the presence of acids, such as hydro-
~ - 21 -
1 ~ ~ $ ~4 ~
chloric acid. Typical reducing metals are zinc, iron and
tin; salts of these metals can al~o be used.
Nitro groups can also be reduced in the Zinin reaction,
which is discussed in "Organic Reactions", Vol. 20, John
Wiley & Sons, N.Y., 1973, page 455 et seq. Generally, the
Zinin reaction involves reduction of a nitro group with
divalent negative sulfur compounds, such as alkali metal
sulfides, polysulfides and hydrosul~ides.
~he nitro groups can be reduced by electrolytic action;
see, for example, the "Amination by Reduction" article,
referred to above.
Typically amino phenols are obtained by reduction of
nitro phenols with hydrogen in the presence of a metallic
catalyst such as discussed above. This reduction is generally
carried out at temperatures of about 15-250C., typically,
about 50-150C., and pressures of about 0-2000 psig, typi-
cally, about 50-250 psig. The reaction time for reduction
usually varies between about 0.5-50 hours. Substantially
inert liquid diluents and solvents, such as ethanol, cyclo~
hexane, etc., can be used to facilitate the reaction. The
amino phenol product is obtained by well-known techniques
such as distillation, filtration, extraction, and so forth.
The reduction is carried out until at least about 50~,
usually about 80%, of the total nitro groups in the nitro
intermediate mixture, are converted to amino groups. The
; typical route to amino phenols just described can be
summarized as
~I) nitrating with at least one nitrating agent at
least one compound of the formula
- 22 -
34~
(IH)c
(R)a -- .Ar'
wherein R is a substantially saturated hydrocarbon-based
group of at least 10 aliphatic carbon atoms; a and c are
each independently an integer of 1 up to three times the
number of aromatic nuclei present in Ar with the proviso
that the sum of a, b and c does not exceed the unsatisfied
valences of Ar'; and Ar' is an aromatic moiety having O to 3
optional substituents selected from the group consisting of
lower alkyl, lower alkoxyl, nitro, and halo, or combinations
of two or more optional substituents, with the provisos that
(a) Ar' has at least one hydrogen atom directly bonded to a
carbon atom which is part of an aromatic nucleus, and (b)
when Ar'is a benzene having only one hydroxyl and one R
substituent, the R substituent is ortho or para to said
hydroxyl substituent, to form a first reaction mixture
containing a nitro intermediate, and (Il) reducing at least
about 50~ of the total nitro groups in said first reaction
mixture to amino groups.
Usually this means reducing at least about 50% of the
nitro groups to amino groups in a compound or mixture of
compounds of the formula
(OH)C
: (R~a -- lr --- ~NO~)b
wherein R is a substantially saturated hydrocarbon-based
substituent of at least 10 aliphatic carbon atoms; a, b and
c are each independently an integer of 1 up to three times
the nu~ber of aromatic nuclei present in Ar with the proviso
that the sum of a, b and c does not exceed the unsatisfied
valences of Ar; and Ar is an aromatic moiety having O to 3
- 23 -
1~9til~8
optional substituents selected from the group consisting of
lower alkyl, lower alkoxyl, halo, or combinations of two or
more of said optional substituents; with the proviso that
when Ar is a benzene nucleus having only one hydroxyl and
one R substituent, the R substituent is ortho or para to
said hydroxyl substituent.
The following examples describe exemplary preparations
of typical amino phenols for use in the two-cycle engine
oils of this invention. As will be readily apparent to
those skilled in the art, amino phenols prepared by other
techniques can also be used. All parts and percentages are
by weight, and all temperatures are in degrees Celsius
(C.), in these examples and elsewhere in this specifi-
cation, unless expressly stated to the contrary.
Exam~le lA
An alkylated phenol is prepared by reacting phenol with
polyisobutene having a number average molecular weight of
approximately lO00 5vapor phase osmometry) in the presence
of a boron trifluoride phenol complex catalyst. Stripping
of the product thus formed first to 230/760 tor (vapor
temperature) and then to 205 vapor temperature/50 tor
provides purified alkylated phenol.
To a mixture of 265 parts of purified alkyl phenol, 176
parts blend oil and 42 parts of a petroleum naphtha having a
boiling point of approximately 20 is added slowly to a
mixture of 18.4 parts of concentrated nitric acid (69-70%)
and 35 parts of water. The reaction mixture is stirred for
3 hours at about 30-45, stripped to 120/20 tor and fil-
tered to provide an oil solution of the desired nitro
- 24 -
~6~9~ 8
phenol intermediate.
Example lB
A mixture of 1,500 parts of the product solution of lA,
642 parts of 2-propanol and 7.5 parts of nickel on kiesel-
guhr catalyst is charged to an autoclave under a nitrogenatmosphere. After purging and evacuation with nitrogen
3 times, the autoclave is pressured to 100 psig with hydrogen
and stirring is begun. The reaction mixture is held at
96C. for a total of 14.5 hours while a total of 1.66 moles
of hydrogen is fed to it. After purging with nitrogen and
evacuating 3 times the reaction mixture is filtered and the
filtrate stripped to 120/18 tor. Filtration provides the
desired product in an oil solution containing 0.54% nitrogen.
Example 2A
lS To a mixture of 400 parts of polyisobutene-substituted
phenol (wherein the polyisobutene substituent contains
approximately 100 carbon atoms), 125 parts of ~extile
spirits and 266 parts of a diluent mineral oil at 28 is
slowly added 22.83 parts of nitric acid (70%) in 50 parts of
water over a period of 0.33 hour. The mixture is stirred at
28-34 for 2 hours and stripped to 158/30 tor, filtration
provides an oil solution (40%) of the desired intermediate
having a nitrogen content of 0.88%.
Exam~le 2B
A mixture of 93 parts of the product solution of
.
` Example 2A and 93 parts of a mixture of toluene and 2-
; propanol (50/50 by weight) is charged to an appropriately
sized hydrogenation vessel. The mixture is degassed and
nitrogen-purged; 0.31 part of a commercial platinum oxide
- 25 ~
34~3
catalyst (86.4% Pto2)is added. The reaction ves~el is
pressured to 57 psig and held at 50-60 for 21 hours. A
total of 0.6 mole of hydrogen is fed to the reaction vessel.
The reaction mixture is then filtered and the filtrate
stripped to yield the desired product in an oil solution
containing 0.44% nitrogen.
Example 3A
A mixture of 2,160 parts of the polyisobutene-sub-
stituted phenol of Example 2A and 1,440 parts of a diluent
mineral oil is heated to 60. Then 25 parts of parafor-
maldehyde is added to the mixture followed by 15 parts of
aqueous hydrochloric acid. The mixture is heated to 115
for 1 hour. After storage for 16 hours at room temperature
ths reaction mixture is heated to 160 for 1 hour while 20
parts of distillate are removed. Stripping of the reaction
mixture to 160/15 tor provides an oil solution of the
desired methylene linked polyisobutene-sub8tituted phenol.
Exam~e 3B
To 2,406 parts of the oil solution described in Example
3A and 600 parts of textile spirits is added 90 parts nitric
acid (70~) over 1.5 hours. The reaction mixture is stirred
for 1.5 hours, stored for 63 hours at room temperature and
then heated for 8 hours at 90. Stripping to 160/18 tor
provides an oil solution of the desired nitrated inter-
~25 mediate containing 0.79% nitrogen.
Example 3C
A mixture of 800 parts of the oil solution of Example
3B and 720 parts of a toluene/2-propanolmixture (60/40 by
weight) is charged to an autoclave. After nitrogen purging,
4 parts of nickel on kieselguhr catalyst is added. Nitrogen
purging is repeated 3 times and the autoclave pressured with
- 26 -
1~6~34~
hydrogen to 60 psig at 25. The reaction temperature is
slowly increased to 96 and the pressure maintained at 100
psig for 5.5 hours. The autoclave is then opened and an
additional 4 parts of nickel on kieselguhr catalyst added.
The autoclave is repressured to 100 psig hydrogen and held
at 96 and 100 psig for 6 hours. The autoclave is cooled
and reopened; an additional 0.8 part of platinum oxide
catalyst added. The autoclave is then repressured to 90
psig with hydrogen and kept at this pressure for 8 more
hours. The reaction mixture is filtered and stripped to
150/18 tor to provide an oil solution of the product having
a nitrogen content of 0.41%.
Exam~le 4A
A mixture of 1,962 parts of the polyisobutene-sub-
stituted phenol of Example lA, 49.5 parts of paraformalde-
hyde, 15 parts of aqueous hydrochloric acid and 1,372 parts
of diluent mineral oil is heated for 7 hours at 115. The
reaction temperature is then increased to 160-165 and held
there for an additional 7 hours. Four hundred parts of
textile spirits is added to the mixture and it is cooled to
30. Then 136.95 parts of nitric acid (70%) in 140 parts of
water is slowly added. The reaction mixture is stirred for
1.5 hours at 30-35 and then stripped to 170/28 tor to
provide an oil solution of the intermediate which is
; 25 clarified by filtration.
ExamRl: 4B
Ninety-six parts of the oil solution described in
Example 4A and 96 parts of a toluene/2-propanol mixture
(50/50 by weight) is charged to an appropriately sized
hydrogenation vessel. After nitrogen purging 0.32 part of
l$q~48
platinum oxide catalyst is added. After again purging the
reaction vessel, it was pressured to 57 psig at 25 with
hydrogen. The hydrogen pressure is kept between 57 and 50
psig for 60 hours while reaction mixture is heated to 50 to
60. The resultant reaction mixture is filtered and stripped
to provide an oil solution of the product having a nitrogen
content of 0.353~.
Example 5A
To a mixture of 654 parts of the polyisobutene sub-
stituted phenol of Example lA and 654 parts of isobutyric
acid at 27 to 31, is added 90 parts of 16 molar nitric acid
over a period of 0.5 hour. The reaction mixture is held at
50 for 3 hours and then stored at room temperature for 63
hours. Stripping to 160/26 tor and filtration through
filter aid provides the desired nitro intermediate which has
a nitrogen content of 1.8%.
Example 5B
The nitro product of Example 5A is hydrogenated using a
nickel on kieselguhr catalyst following essentially the same
procedure described in Example lB.
Exam~le 6A
A mixture of 4,578 parts of the polyisobutene-sub-
stituted phenol of Example lA, 3,052 parts of diluent
mineral oil and 725 parts of textile spirits is heated to
~25 60 to achieve homogenity. After cooling to 30, 320
parts of 16 molar nitric acid in 600 parts of water is added
to the mixture. Cooling is necessary to keep the mixture
below 40. After stirring the reaction mixture for an
additional 2 hours, 3,710 parts is transferred to a second
- 28 -
6~3~8
reaction vessel. This 3,710 parts is treated with an
additional 128 parts of 16 molar nitric acid in 130 parts
of water at 25-30. The reaction mixture is stirred for 1.5
hours and then stripped to 220/30 tor. Filtration provides
an oil solution of the intermediate.
Example 6B
The oil solution of the product formed in Example 6A is
hydrogenated using a platinum oxide catalyst in substan-
tially the same fashion as described in Example 18.
Exa~ 7
A mixtur~ of 543 parts of a dinitro C2 5 alkylated
phenol (prepared in essentially the same manner as described
in Example 6A), 543 parts of isopropanol and 200 parts of
toluene is treated at 19C. with a total of 42 parts of
gaseous ammonia over a 0.75 hour period. The reaction
mixture is then treated with 147 parts of gaseous H2S.
Both the ammonia and hydrogen sulfide treatment are carried
out by introducing the gas into the stirred mixture under
its surface. Ammonia treatment is repeated with 82 parts of
gaseous ammonia followed by a final treatment with 102 parts
of hydrogen sulfide. Stripping of the reaction mixture to
40/60 tor yields a residue which is combined with 161 parts
of diluent oil and stripped again to 70C./18 tor. An
additional 161 parts of diluent oil and 35 parts of filter
aid are added, filtration of this mixture yields a viscous
filtrate which is a 40% oil solution of the diamino phenol.
The nitrations in examples 8-14 are carried out in
essentially the same manner described in Example lA, using
the hydroxy aromatic compounds and amounts of nitric acid
indicated in Table A. Reduction of the nitro intermediates
in these examples is carried out using the technique described
in the examples indicated in Table A.
.
- 29 -
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30 -
In general, the two-cycle engine lubricating oil
compositions of this invention contain about ~8 to about 55%
oil or mixture of oils of lubricating viscosity. Typical
compositions contain about ~0 to about 70~ oil. The
presently preferred oils are mineral oils and mineral oil-
synthetic polymer and/or ester oil mixtures. Polybutenes of
molecular weights of about 250 to about 1,000 (as measured
by vapor phase osmometry) and fatty acid ester oils of
polyols such as pentaerythritol and trimethylol propane are
typical useful synthetic oils.
These oil compositions preferably contain about 2 to
about 30~, more preferably about 5 to about 20~, of at least
one amino phenol as described hereinabove. Other additives
such as auxiliary detergents and dispersants of the ash-
producing or ashless type, anti-oxidants, coupling agents,
pour point depressing agents, extreme pressure agents, color
stabilizers ana anti-foam agents can also be present.
Deter~ent-dispersants of ashless types and ash-
producing metallic types are used to control piston ring
sticking and general engine cleanliness. The heavier duty
two-cycle lubricants require the use of suitable ashless
dispersants because of the proneness of the reference engine
to deposit induced preignition. Other formulations use calcium,
barium or magnesium sulfonates either singly, in combination
with one another, or in combination with ashless dispersants.
Anti-oxidants can be included to promote lubricant thermal
stability.
Polymeric VI improvers have been and are being used
as bright stock replacement in the hope of improving lubricant
film strength and lubrication and improving engine cleanliness.
Dye may be used for identification purposes and to
1~9~i~48
indicate whether a two-cycle fuel mix contains lubricant.
Coupling agents are incorporated into some products to
provide better component solubilities and improved fuel/
lubricant mix water tolerance.
Anti-wear and lubricity improvers, particularly sul-
furized sperm oil substitutes and other fatty acid and
vegetable oils, such as castor oil, are used in special
applications, such as racing and for very high fuel/lub-
ricant ratios. Scavengers or combustion chamber deposit
modifiers are sometimes used to promote better spark plug
life and to remove carbon deposits. Xalogenated compounds
and/or phosphorous containing materials may be used for this
application.
Rust and corrosion inhibitors of all types are and may
be incorporated into two-cycle oil formulations. Odorants
or deodorants are sometimes used for aesthetic reasons.
; Lubricity agents such as synthetic polymers (e.g.,
polyisobutene having a number average molecular weight in
the range of about 750 to about 15,000), as measured by
vapor phase osmometry or gel permeation chromatography,
polyol ether (e.g., poly(oxyethylene-oxypropylene)ethers)
and ester oils (e.g., the ester oils described above) can
` also be used in *he compositions of this invention. Natural
oil fractions such as bright stocks (the relatively viscous
products formed during conventional lubricating oil manu-
facture from petroleum) can also be used for this purpose.
They are usually present in the two-cycle oil in the amount
of about 3 to about 20% of the total oil composition.
As noted above the oils of this invention can also
contain auxiliary detergent-dispersants. Typical examples
are the amide, amine salt and/or amidine products formed by
- 32 -
~6~
reaction of fatty acids of 5 to 22 carbon atoms (e.g.,
isostearic acid and mixtures of isostearic and stearic acid)
with an alkylene polyamine of 2 to about 10 amino groups and
2 to 20 carbon atoms, such as ethylene diamine, diethylene
triamine, triethylene tetramine, tetraethylene pentamine,
etc., including comrnercially available mixtures of such
alkylene polyamines. Such auxiliary detergent-dispersants
are represented by those disclosed in U.S. Patent No.
3,16~,980.
Diluents such as petroleum napthas boiling at the
range of about 38-90 (e.g., Stoddard Solvent) can also be
included in the oil compositions of this invention, typically
in an amount of 5 to 25%.
An illustrative two-cycle engine oil lubricant
composition contains 2-10~ of one or more amino phenols
described hereinbefore such as that desribed in Example lB,
and a base oil composed of about 70-80 parts by volume 650
neutral oil, 8-12 parts by volume bright stock and 10-20 parts
by volume Stoddard Solvent.
In some two-cycle engines the lubricating oil may be
injected into the combustion chamber along with the fuel or
into the fuel just prior to the time the fuel enters the
combustion chamber. The two-cycle lubricants of this invention
are intended for use in such two-cycle engines.
As is well known to those skilled in the art, two-
cycle engine lubricating oils can be added directly to the fuel
to form a mixture of oil and fuel which is then introduced into
the engine cylinder. Such lubricant-fuel oil mixtures are
within the scope of this invention. Such lubricant-fuel
30 blends generally contain per 1 part of oil about 15-250
1~6~4~3
parts fuel, typically they contain 1 part oil to about 50-
100 parts fuel.
Typical specific examples of the two-cycle engine oils
of this invention are the following:
Com~onent Wei~h-t_Percent
Example A Example B
Base Oill 58.6 67.0
Bright Stock 2 9 . 4 9.4
Stoddard Solvent 17.9 17.8
Amino Phenol Additive 3314.1 ----
Amino Phenol Additive 14 ---- 5.8
.
-A solvent~refined neutral oil having a viscosity of
650 SUS at 98.8C.
2-Having a viscosity of 150 SUS at 98.8C
3-A mineral oil solution containing 60% of the amino phenol
deocribed in Example 3C
` ~ 4-A mineral oil solution containing 60% of the amino phenol
described in Example lB
The fuels used in two-cycle engines are well known to
those skllled in the art and usually contain a major portion
of a normally liquid fuel such as hydrocarbonaceous petroleum
distillate fuel (e.g., motor gasoline as defined ~y ASTM
Specification D-439-73). Such fuels can also contain non-
hydrocarbonaceous materials such as alcohols, ethers,
organo-nitro compounds and the like (e.g., methanol, ethanol,
diethyl ether, methyl ethyl ether, nitromethane) axe also
::
within the scope of this invention as are liquid fuels
derived from vegetable or mineral sources such as corn,
~ alfalfa, shale and coal. Examples of such fuel mixtures are
combinations of gasoline and ethanol, diesel fuel and ether,
- 34 -
1~6~348
gasoline and nitromethane, etc. Particularly pref~rred is
gasoline, that is, a mixture of hydrocarbons havin~ an ASTM
boiling point of 60C. at the 10~ distillation point to
about 205C. at the 90~ distillation point.
Two-cycle fuels also contain other additives which are
well known to those of skill in the art. These can include
anti-knock agents such as tetra~alkyl lead compounds, lead
scavengers such as halo-alkanes (e.g., ethylene dichloride
and ethylene dibromide), deposit preventors or modifiers
such as triaryl phosphates, dyes, cetane improvers, anti-
oxidants such as 2,6-di-tertiary-butyl-4-methylphenol, rust
inhibitors, such as alkylated succinic acids and anhydrides,
bacteriostatic agents, gum inhibitors, metal deactivators,
demulsifiers, upper cylinder lubricants, anti-icing agents
and the like.
- 35 -
