Note: Descriptions are shown in the official language in which they were submitted.
iO5~151
This invention relates to new compositions of
matter suitable for causing swelling of seals in machinery,
and to methods of causing said swelling of seals. More
particularly, it relates to compositions comprising an
oleaginous liquid of lubricating viscosity and a substituted
sulfolane of the formula
R2 ORI
R3
SO2
wherein Rl is a hydrocarbon-based radical having at least
abou~ 4 carbon atoms and each of R2 and R3 is hydrogen or a
lower alkyl-based radical.
The problem of shrinkage of seals, particularly
elastomeric seals, in machinery (e.g., automatic trans-
missions for motor vehicles) upon contact with functional
fluids is of considerable importance since such shrinkage
causes leakage of the functional fluid which can lead to
defective operation of the machinery, or failure to operate
at all. (The term "functional fluid", as used herein,
means a fluid involved in the transmission of energy, such
as a lubricant, hydraulic fluid, automatic transmission
fluid, heat exchange medium or the like.) To eliminate this
problem, it is conventional to include in the functional
fluid an additive whose presence therein causes the seal to
swell. A number of such additives are known in the art, but
their use has several disadvantages. For example, many of
them are toxic. Moreover, they must often be used in unde-
sirably large quantities in the functional fluid.
A principal object of the present invention, there-
fore, is to provide new compositions of matter capable of
swelling or minimizing shrinkage of seals used in machinery,
and methods of causing such swelling.
--1--
1058~Sl
` A further o~ject is to provide seal-swelling
lubricants and functional fluids which contain relatively
non-toxic additives.
A further object is to provide lubricants and
iunctional fluids containing extremely small but effective
quantities of seal swelling additives.
Other objects will in part be obvious and will
in part appear hereinafter.
As previously noted, the compositions of this
invention comprise two components of which the ~irst
is an oleaginous li~uid of lubricating viscosity. Such
liquids include natural and synthetic oils and mixtures
thereof, especially oils of the type useful as crankcase
lubricating oils for spark-ignited and compression-ignited
~15 internal combustion engines, including automobile and
truck engines, two-cycle engines, aviation piston engines,
marine and railroad diesel engines, as well as gas engines,
jet aircraft turbines, stationary power engines and turbines
and the like. Base liquids for automatic transmission
fluids, transaxle lubricants, gear lubricants, metal-working
lubricants, hydraulic fluids and other lubricating oil and
grease compositions are also useful for this purpose.
Natural oils include animal oils and vegetable
- oils (e.g., castor oil, lard oil) as well as liquid petro-
leum oils and solvent-treated or acid-treated mineral lubri-
~ating oils of the paraffinic, naphthenic or mixed paraf-
finic-naphthenic types; such mineral oils are preferred.
Oils of lubricating viscosity derived from coal or shale
are also useful.
Synthetic lubricating oils include hydrocarbon
oils and halo-substituted hydrocarbon oils such as polymer-
~ ` ~058151
iæed and interpolymerized olefins le.g., polybutylenes,
polypropylenes, propylene-isobutylene copolymers, chlori-
nated polybutylenes, poly(l-hexenes), poly(l-octenes),
. poly(l-decenes), etc. and mixtures thereofl; alkylbenzenes
~e.g., dodecylbenzenes, tetradecylbenzenes, dinonyl-
benzenes, di-(2-ethylhexyl)benzenes, etc.); polyphenyls
(e.g., biphenyls, terphenyls, alkylated polyphenyls, etc.),
~- alkylated diphenyl ethers and alkylated diphenyl sulfides
and the derivatives, analogs and homologs thereof and the
like. --
Alkylene oxide polymers and interpolymers and
.
derivatives thereof where the terminal hydroxyl groups have
~ ~ been modified by esterification, etherification, etc. con-
;~ ~ stitute another class of known synthetic oils. These are
I5 exemplified by the oils prepared through polymerization of
ethylene oxide or propylene oxi&e, 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
,
~20 having a molecular weight of 500-1000, diethyl ether of
; polypropylene 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,
esters, or the Cl 3 OXO acid diester of tetraethylene glycol.
Another suitable class of synthetic oils comprises
the esters of dicarboxylic acids (e.g., phthalic acid,
succinic acid, alkyl succinic acids and alkenyl succinic
acids, maleic acid, azelaic acid, suberic acid, sebacic
acid, fumaric acid, adipic acid, linoleic acid dimer,
malonic acid, alkyl malonic acids, alkenyl malonic acids,
etc.) with a variety of alcohols (e.g., butyl alcohol,
.
-3-
` ~()S815~
hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol,
ethylene glycol, diethylene glycol monoether, p~opylene
glycol, etc.). Specific examples of these esters include
dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl
; 5 fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl
azelate, dioctyl phthalate, didecyl phthalate, dieicosyl
sebacate, the 2-ethylhexyl diester of linoleic acid dimer,
the complex ester formed by reacting one mole of sebacic
acid with two moles of tetraethylene glycol and two moles
of 2-ethylhexanoic acid, and the like.
Esters useful as synthetic oils also include
those made from C5 to Cl 2 monocarboxylic acids and polyols
~ and polyol ethers such as neopentyl glycol, trimethylol-
.
propane,~pentaerythritol, dipentaerythritol, tripentaeryth-
~ 15 ritol, etc.
; ~ - - Siiicon-based oils such as the polyalkyl-,
.- ~
polyaryl-, polyalkoxy-, or polyaryloxy-siloxane oils and
silicate oils comprise another useful class of synthetic
oils [e.g., tetraethyl silicate, tetraisopropyl silicate,
,
- tetra-(2-ethylhexyl) silicate, tetra-(4-methyl-2-ethylhexyl)
silicate, tetra-(p-tert-butylphenyl) silicate, hexyl-
- (4-methyl-2-pentoxy)disiloxane, poly(methyl)siloxanes,
poly(methylphenyl)siloxanes, etc.]. Other synthetic oils
- include liquid esters of phosphorus-cor.taining acids (e.g.,-
tricresyl phosphate, trioctyl phosphate, diethyl ester of
. decylphosphonic acid, etc.), polymeric tetrahydrofurans
and the li~e.
- Unrefined, refined and rerefined oils ~and mixtures
of each with each other) of the type disclosed hereinabove
can be used in the compositions of the present invention.
Unrefined oils are those obtained directly from a natural or
`'` ~()58~S~
synthetic source without further purification treatment.
For example, a shale oil obtained directly from retorting
operations, a petroleum oil obtained directly from di~-
tillation or ester oil obtained directly from an esterifi-
cation process and used without further treatment would bean unrefined 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 purification techniques are known to those of s~ill in
the art such as solvent extraction, 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 refined oils are also known as reclaimed or
1J rep~ocesscd GilS and GCt2n aï c ad~iticnally process2d by
techniques directed to removal of spent additives and oil
breakdown products.
The substance which serves as a seal swelIing
component in the caffipositions of this invention is a sub-
stituted sulfolane having the above formula. (When used
herein, the singular form "a", "an" and "the" include theplural unless the context clearly dictates otherwise; thus,
for example, "a compound" includes a mixture of compounds.)
In the formula, Rl is a hydrocarbon-based radical having at
least about 4 carbon atoms. The term "hydrocarbon-based
radical", when used herein, denotes a radical having a
carbon atom directly attached to the remainder of the molecule
and having predominantly hydrocarbon character within the
context of this invention. Such radicals include the follow-
ing: .
1~581Sl
(1) Hydrocarbon radicals; that is, aliphatic,(e.g., alkyl or alken~l), alicyclic (e.g., cycloalkyl or
cycloalkenyl), aromatic, aliphatic- and alicyclic-substi-
tuted aromatic, aromatic-substituted aliphatic and alicyclic
radicals, and the like. Such radicals are known to those
skilled in the art; examples include butyl, pentyl, hexyl,
octyl, decyl, dodecyl, eicosyl, decenyl, cyclohexyl, phenyl,
tolyl, heptylphenyl, isopropenylphenyl and naphthyl (all
isomers of such radicals being included when more than one
isomer is possible).
(2) Substituted hydrocarbon radicals; that is,
radicals containing non-hydrocarbon substituents which, in
the context of this invention, do not alter the predominantly
hydrocarbon character of the radical. Those skilled in the
art will be aware of suitable substituents; examples are
O O O
11 11 11
halo, nitro, cyano, RO-, RC-, ROC-, R2N-, R2NC-, RS-, Rl-,
O
O O
RS- and ROS- (R being hydrogen or a hydrocarbon radical).
O O
(3) Hetero radicals; that is, radicals which,
while predominantly hydrocarbon in character within the
context of this invention, contain atoms other than carbon
present in a chain or ring otherwise composed of carbon
atoms. Suitable hetero atoms will be apparent to those
skilled in the art and include, for example, oxygen, nitro-
gen and sulfur.
' ` 1058151
;In general, no more than about three substitu-
ents or hetero atoms, and preferably no more than on~,
will be present for each 10 carbon atoms in the hydrocar-
bon-based radical.
Terms such as "alkyl-based radical" and the like
have meanings analogous to the above with respect to alkyl
radicals and the like.
The preferred substituted sulfolanes are those
in which Rl is a hydrocarbon radical, usually one which is
free from acetylenic unsaturation and which contains about
4-100 carbon atoms. Examples (all isomers being included)
are butyl, amyl, hexyl, octyl, decyl, dodecyl, eicosyl,
triacontanyl, buteny~l, dodecenyl, phenyl, naphthyl, tolyl,
dodecylphenyl, tetrapropene-alkylated phenyl, phenethyl,
cyclohexyl and methylcyclohexyl. Alkyl radicals having
about 4-25 and usually about 4-10 carbon atoms are
- especially preferred.
Each of R2 and R3 is hydrogen or a lower alkyl-
based (and usually a lower alkyl) radical, the word "lower"
denoting radicals containing up to 7 carbon atoms. Examples
of lower alkyl radicals (all isomers being included, but
especially the straight chain radicals) are methyl, ethyl,
propyl, butyl and hexyl, with methyl being preferred. ~lost
often, one of R2 and R3 is hydrogen and the other (usually
R3) is hydrogen or methyl. Both are preferably hydrogen.
The preferred substituted sulfolanes for use in
the compositions of this invention are those in which R2
and R3 are hydrogen and Rl is either the isodecyl radical
or a combination of the isobutyl radical with a mixture of
primary amyl radicals, the iso~utyl material comprising
about 25-75% (by weight) of said combination.
--7~
'` lOSt~5~ .
The above-described substituted sulfolanes com-
prise a class of compounds which is known in the art.
They may be prepared by the reaction o 3-sulfolene or a
substituted derivative thereof with an organic hydroxy
compound, ordinarily an alcohol, This method for their
preparation is described, for example, in U.S. Patent
2,393,~25, and in Data Sheet DS-58:3 of Shell Development
Company entitled "3-Sulfolene". The 3-sulfolenes may be
prepared by reaction of sulfur dioxide with a conjugated
diene such as butadiene or isoprene.
The compositions of this invent-on which are
useful as functional fluids contain a minor amount of sub-
stituted sulfolane effec~ive to cause swelling of seals.
That amount is usually about 0.05-20.0 parts (by weight),
preferably about 0.1-5.0 parts, per 100 parts of oil.
However, the invention includes additive concentxates com-
prising a diluent (typically an oleaginous liquid of lubri-
cating viscosity) and the substituted sulfolane, the latter
comprising up to about 90~ of the weight o the concentrate.
Such concentrates may be diluted with the oleaginous liquids
as described hereinabove, as is well known in the art, to
produce functional fluids.
The present invention also contemplates functional
fluids and concentrates containing other additives in com-
bination with the substituted sulfolane. Such additives
include, for example, detergents and dispersants of the ash-
containing or ashless type, corrosion- and oxidation-inhibi-
ting agents, pour point depresging agents, extreme pressure
agents, viscosity index improvers, color stabilizers and
anti-foam agents.
- The ash-containing detergents are exemplified by
oil-soluhle neutral and basic salts of alkali ox alkaline
--8--
'` 1058151
`
earth metals with sulfonic acids, carboxylic acids, or
organic phosphorus acids characterized by at least one
direct carbon-to-phosphorus linkage such as those prepared
by the treatment of an olefin polymer (e.g., polyisobutene
having a molecular weight of 1000) with a phosphorizing
agent such as phosphorus trichloride, phosphorus heptasul-
fide, phosphorus pentasulfide, phosphorus trichloride and
sulfur, white phosphorus and a sulfur halide, or phosphoro-
thioic chloride. The most commonly used salts of such acids
- 10 are those of sodium, potassium, lithium, calcium, ma~nesium,
strontium and barium.
The term "basic salt" is used to designate metal
salts wherein the metal is present in stoichiometrically
larger amounts than the organic acid radical. The commonly
lS ~ employed methods for preparing the basic salts involve
heating a mineral oil solutLon of an acid with a stoichio-
metric excess of a metal neutralizing agent such as the
metal oxide, hydroxide, carbonate, bicarbonate, or sulfide
: . .
~ at a temperature above 50C. and filtering the resulting
, - :
~mass. The use of a "promoter" in the neutralization step
to aid the incorporation of a large excess of metal likewise
is known. Examples of compounds useful as the promoter
- include phenolic substances such as phenol, naphthol,
~ `
- ~ ~ alkylphenol, thiophenol, sulfurized alkylphenol, and con-
densation products of formaldehyde with a phenolic sub-:
stance; alcohols such as methanol, 2-propanol, octyl alcohol,
- cellosolve, carbitol, ethylene glycol, stearyl alcohol, and
cyclohexyl alcohol; and amines such as aniline, phenylene-
diamine, phenothiazine, phenyl-~-naphthylamine, and dodecyl-
amine. A particularly effective method for preparing the
iO58~5~
basic salts comprises mixing an acid with an excess of a
basic alkaline earth metal neutralizing agent and at
least one alcohol promoter, and carbonating the mixture at
an elevated temperature such as 60-200C.
Ashless detergents and dispersants are illustra-
ted by the interpolymers of an oil-solubili~ing monomer,
e.g., decyl methacrylate, vinyl decyl ether, or high molecu-
lar weight olefin, with a monomer containing polar sub-
stituents, e.g., aminoalkyl acrylate or poly-(oxyethylene)-
substituted acrylate; the amine salts, amides, and imides
of oil-soluble ~onocarboxylic or dicarboxylic acids such as
stearic acid, oleic acid, tall oil acid, and high molecular
weight alkyl or alkenyl-substituted succinic acid. Especial-
ly useful as ashless detergents are the acylated polyamines
and similar nitrogen ~mpounds containing at least ~bout
54 carbon atoms as described in U.S. patent 3,272,746;
reaction products of such compounds with other reagents
including boron compounds, phosphorus compounds, epoxides,
aldehydes, organic acids and the like; and esters of hydro-
carbon-substituted succinic acids as described in U.S.
patent 3,381,022.
Extreme pressure agents ana corrosion-inhibiting
and oxidation-inhibiting agents are exemplified by chlor-
inated aliphatic hydrocarbons such as chlorinated wax;
organic sulfides and polysulfides such as benzyl disul-
fide, bis(chlorobenzyl) disulfide, dibutyl tetrasulfide,
sulfurized methyl ester of oleic acid, sulfurized alkyl-
phenol, sulfurized dipentene, and sulfurized terpene; phos-
phosulfurized hydrocarbons such as the reaction product of a
phosphorus sulfide with turpentine or methyl oleate; phos-
phorus esters including principally dihydrocarbon and
-10-
` 105~5~
trih~drocarbon phosphites such as dibutyl phosphite,
diheptyl phosphite, dicyclohexyl phosphite, pentyl phenyl
phosphite, dipentyl phenyl phosphite, tridecyl phosphite,
distearyl phosphite, dimethyl naphthyl phosphite, oleyl
4-pentylphenyl phosphite, polypropylene (molecular weight
S00)-substituted phenyl phosphite, diisobutyl-substituted
phenyl phosphite; metal thiocarbamates, such as zinc
dioctyldithiocarbamate, and barium heptylphenyl dithio-
~arbamate; Group II metal phosphorodithioates such as zinc
dicyclohexylphosphorodithioate, ~inc dioctylphosphorodi-
thioate, barium di(heptylphenyl)phosphorodithioate, cadmium
dinonylphosphorodithioate, and the zinc salt of a phosphoro-
dithioic acid produced by the reaction of phosphorus penta-
sulfide with an equimolar mixture of isopropyl alcohol and
n-hexyl alcohol.
Typical compositions according to this invention
- are listed in the following table. All amounts other than
those for mineral oil are exclusive of oil used as diluent.
The substituted sulfolanes are those of the above structural
formula wherein Rl is as listed and R2 and R3 are each
hydrogen.
,
~058~5~
;
. Parts by ~eight
In~xedient A B C D
Mineral oil (SAE lOW-40 base) ~ -- 90.29 85.83
Mineral oil (automatic trans-
mission fluid base) ~2.91 94.95 -~- ---
Substituted sulfolane, Rl =
isodecyl --- 0.50 2.00 2.00
Substituted sulfolane,
Rl = mixture of isobutyl
and primary amyl 1.00 --- --- ---
Reaction product of ethylene
polyamine with pol.yiso- .
butenyl succinic ~nhydride 3.09 1.71 -~
Borated reaction product of
ethylene polyamine with
polyisobutenyl succinic
anhydride 0.68 0.67 0.74 ---
Pentaerythritol ester of
polylsob~tenyl su CGi nic
acid . . --- --- --- 2.35
Reaction product of penta-
erythritol and ethylene
polyamine with polyiso-
butenyl succinic anhydride --- --- 2.30 --- -
. Basic calcium petroleum
sulfonate -. -~ - 0.75
Tetrapropenyl succinic acid --- --- 0.34 ---
Zinc isooctylphosphoro-
dithioate 0.66 --- --- ---
Zinc salt of mixed iso-
butyl- and prim-amyl-
phosphorodithioic acids --- --- --- 1.32
Dialkyl (~-hydroxy-Cl 4 - 1 6
alkyl) phosphonate 0.13 --- --- ---
Phenyl Cl 4 - 1~ dialkyl
phosphite --- 0.20 --- ---
N-tallow diethanolamine 0.10 --- --- ---
N-dodecyl dipropanolamine 0.04 --- --- ---
Diphenylamine-based anti-
oxidant 0.20 0.50 -~
105815~
Parts by we,ight
In redient A B C D
g
Hindered phenol antioxidant -~- --- 0.50 ---
Sulfurized alkyl cyclo-
hexenecarboxylate --- --- 1.33 ---
Sulfurized fatty ester-
fatty acid-olefin mixture --- 0.30 --- ---
Styrene-butadiene copolymer --- --- 2.50 ---
Styrene-alkyl maleate
copolymer 1.19` 1.17 --- ---
Polyacrylate viscosity index
improver --- --- --- 7.75
Silicone anti-foam agent 0.020.02 0.01 0.01
.
