[0001] This invention relates to functional fluids and lubricants which exhibit improved
water tolerance properties. More particularly, the invention relates to mineral oil
or synthetic oil based functional fluid compositions which contain effective amounts
of certain oil-soluble, alkoxypolyethyleneoxy mono- or di-acid phosphite ester additives,
which additives are highly effective in improving the water tolerance properties of
such compositions.
[0002] U.S. Patent No. 2,280,450 describes hydrocarbon oils of improved resistance to corrosion
containing a small amount of a substantially stable oil-soluble water-insoluble reaction
product of tricresyl phosphite and octyl phenoxyethanol. The mole ratio of tricresyl
phosphite to octyl phenoxyethanol varies from 1:1 to about 1:2.5. The reaction product
is described as a complex ester of phosphorous acid, which may or may not contain
unreacted octyl phenoxyethanol. The product is not however an acid phosphite, and
it is not suggested that the water tolerance of the resulting composition is improved..
[0003] U.S. Patent No. 3,583,915 provides industrial fluid compositions and lubricant compositions
containing improved load-carrying additives, including a diorgano hydrogen phosphonate
in which at least one organic group is an aliphatic group containing at least fourteen
carbon atoms in admixture with an active sulfur compound.
[0004] U.S. Patent No.3,652,410 provides multifunctional lubricant additive compositions
and lubricating oils containing, among other things, an organic acid phosphate or
organic phosphite containing at least one alkyl or alkenyl group having from about
12 to about 24 carbon atoms. Also present is a mineral oil soluble or dispersible
basic detergent, a mineral oil antioxidant, a sulfurized fat, or an alkyl sulfide
or alkyl polysulfide.
[0005] U.S. Patent No. 4,346,148 and U.S. Patent No. 4,358,509 describe reaction products
of alkoxylated alkyl phenol and a phosphorus trihalide which are included in lubricating
compositions useful in metal-working operations, imparting corrosion resistance, extreme
pressure properties, and protection against wear of working parts.
[0006] U.S. Patent No. 3,115,465 provides antioxidant combinations for organic materials,
including lubricants, comprising an oil-soluble phosphite ester having the formula:

wherein R
1 and R
2 are alkyl, alkoxyalkyl, haloalkyl, cycloalkyl, halocycloalkyl, aralkyl, aryl, alkaryl,
haloaryl or haloalkaryl radicals and R
3 is hydrogen or one of the aforesaid radicals; and from about 0.01 to about 5, preferably
0.25 to 2%, by weight based on the oil of a methylene bis-phenol having the formula:

wherein R
4 is an alkyl group containing 3 to 12 carbon atoms, the group being branched on its
alpha carbon atom, and R
5 is an alkyl group of 1 to 12 carbon atoms.
[0007] None of the foregoing references disclose the improvement in water tolerance properties
achieved in accordance with the present invention. Water compatibility is a highly
significant property of functional fluids and lubricants, which, under severe conditions,
come into contact with water and in the absence of acceptable water tolerance properties
the fluid will have its lubricating and power transmission properties substantially
reduced. The specifications of many equipment manufacturers require that the fluids
and lubricants used therein have certain water tolerance properties, for example,
fluids for use in agricultural machinery, such as tractor fluids.
[0008] In accordance with the present invention there have been discovered improved functional
fluids and lubricating compositions comprising a major amount of a synthetic or mineral
oil of lubricating viscosity and an amount, effective to improve the water tolerance
properties of the composition, of an oil-soluble alkoxypolyethyleneoxy acid phosphite
ester additive of the formula:

wherein:
R1 is alkyl or alkenyl and R2 is OH, alkoxy, oxy-alkenyl, or R1O[CH2CH2O]x, in which the total number of carbon atoms in the alkyl, alkenyl, alkoxy or oxyalkenyl
groups is about 8 to 36; and x is a number (which can be a whole number or a fractional
number) representing the average number of [CH2CH20] groups, and ranges from about 2 to about 4. Preferred phosphite additives are those
wherein x is 2, 2.5, 3.5 or 4.
[0009] In R
1 and R
2, alkyl and alkenyl groups include octyl, 2-ethyl hexyl, isooctyl, tertiary-octyl,
nonyl, isononyl, tertiary-nonyl, secondary-nonyl, decyl, isodecyl, undecyl, dodecyl,
tridecyl, palmityl, stearyl, and isostearyl; octenyl, nonenyl, decenyl, dodecenyl,
oleyl, linoleyl and linolenyl.
[0010] Acid phosphites according to the invention include di(octyl di(ethyleneoxy)) phosphite,
di(isooctyl tri-(ethyleneoxy)) phosphite, di(2-ethylhexyl-tetra(ethy- leneoxy)) phosphite,
di(nonyl-di(ethyleneoxy)) phosphite, di(isodecyl-tri(ethyleneoxy)) phosphite, di(palmityl-tetra-(ethyleneoxy))
phosphite, di(stearyl tri(ethyleneoxy)) phosphite, octyl di(ethyleneoxy) phosphite,
stearyl di(ethyleneoxy) phosphite, and octyl(tri(ethyleneoxy))-nonyl(tetra(ethyleneoxy))
phosphite; octyl di(ethylene- o×y))octy1 phosphite, isooctyl tri-(ethyleneoxy) oleyl
phosphite, 2-ethylhexyl-tetra(ethyleneoxy) decyl phosphite, nonyl-di(ethyleneoxy)
nonyl phosphite, isodecyl-tri(ethy- leneoxy) linoleyl phosphite, palmityl-tetra(ethyleneoxy)
stearyl phosphite, stearyl-tri(ethyleneoxy) stearyl phosphite, octyl di(ethyleneoxy)
stearyl phosphite, stearyl di(ethyleneoxy) oleyl phosphite, and octyl tri(ethyleneoxy)
nonyl phosphite.
[0011] The oil-soluble phosphite ester additive of this invention will provide effective
water tolerance properties to a wide variety of functional fluid and lubricating compositions
and these include hydraulic fluids, compressor oils, pump oils, tractor fluids and
universal tractor fluid compositions, gear oils, hydrostatic transmission oils, power
shift transmission fluids and the like. Such functional fluids and lubricating compositions
will also contain a number of conventional additives in amounts as required to provide
their normal attendant functions. Such additives include viscosity modifiers or viscosity
index improvers, corrosion inhibitors, oxidation inhibitors, friction modifiers, dispersants,
demulsifiers, anti-foam agents, anti-wear agents, pour point depressants, seal swellants
and other special purpose additives.
[0012] Typical viscosity modifiers include polyisobutylene, ethylene-propylene copolymers,
polymethacrylates, styrene-acrylic ester copolymers and vinyl monomer unsaturated
dicarboxylic acid (or ester) copolymers. Corrosion inhibitors include zinc dialkyl
dithiophosphates and phosphosulfurized hydrocarbons and reaction products thereof
with alkaline earth metal oxides or hydroxides, preferably in the presence of alkyl
phenols or alkyl phenol thioethers. Oxidation inhibitors are illustrated by alkaline
earth metal salts of alkyl (C
5-C
12) phenol thioethers.
[0013] Dispersants are well known in the art and include oil-soluble alkenyl succinimides,
e
qg. the reaction products of polyisobutenyl succinic anhydrides with ethylene amines
and borated derivatives. Exemplary pour point depressants are C
8-C
18 dialkylfumarate/vinyl acetate copolymers, polymethacrylates and wax-naphthalene condensation
products. Anti-foam agents are typically polysiloxane materials such as silicone oil
and polydimethyl siloxane; anti-wear agents include zinc dialkyl (or diaryl) dithiophosphates
and magnesium sulfonates. Seal swellants are typified by mineral oils that provoke
swelling, C
8-C
13 aliphatic alcohols and C
10-C
60 hydrocarbon esters having 2-4 ester linkages such as dihexylphthalate.
[0014] The oil-soluble phosphite ester additive of this invention will be present in amounts
effective to provide acceptable water tolerance properties to the particular composition
and the desired amount will vary according to the service conditions but generally
the additives of this invention will be present in an amount of about 0.05 to 5% by
weight, based on the weight of the total lubricating oil or funct-ional fluid-composition-and
preferably from about 0.2 to 2% by weight percent.
[0015] Typical base oils for such functional fluids and lubricating compositions include
a wide variety of hydrocarbon mineral oils such as naphthene base, paraffin base and
mixtures thereof having a lubricating viscosity range of about 34 to 45 Saybolt Universal
Seconds (SUS) at 35°C. Examples of synthetic oils useful in the compositions of the
present invention include olefin oligomers, alkylated aromatics, polybutene oils,
cycloaliphatic compounds, dibasic acid esters, polyol esters, polyglycerol fluids,
phosphate esters, silicone oils and halogenated hydrocarbon fluids and mixtures thereof.
[0016] The following examples illustrate the preferred embodiments of the oil soluble phosphite
ester additives of this invention: (EO refers to ethylene oxide)
EXAMPLE I
Di(C9-C11 alkyl 2.5 EO) phosphite
[0017] 159.8g of triphenyl phosphite (97%) and 405g of (mixed alkyl(oxyethylene)
2.5 alcohols, the alkyl having from nine to eleven carbon atoms, and 0.6g of K
2C0
3 were heated at 85°C for three hours. Vacuum was then applied (6 mm) with heating
to a maximum temperature of 170°C to remove phenol. The weight of volatiles collected
was 150.9g (theory 145.8). To the transesterified product 15.63g of phosphorous acid
was added with agitation and the mixture heated to 85°C for 5 hours with agitation,
giving clear reaction product having the formula:

EXAMPLE II
[0018] Di(C
12-C
15alkyl-3EO) phosphite was prepared from triphenyl phosphite (97%), and (mixed alkyl(oxyethylene)
3 alcohols, the alkyl having from eleven to fifteen carbon atoms)using the procedure
of Example I. The compound has the formula:

Control A
[0019] Di(C
12- C
15 alkyl-7EO) phosphite was prepared from triphenyl phosphite (97%), and mixed C
12-C
15 (oxyethylene)
7 alcohols using the procedure of Example I. The compound has the formula:

Control B
[0020] Ethoxylated nonylphenol (9.5EO) phosphite was prepared from triphenyl phosphite and
ethoxylated nonylphenol using the procedure of Example I. The compound has the formula:

EXAMPLE III
[0021] Mono(C
9-11 alkyl 2.5EO) mono oleyl phosphite was prepared from triphenyl phosphite ((mixed alkyl
oxyethylene)
2.5 alcohols, the alkyl having from nine to eleven carbon atoms), and oleyl alcohol using
the procedure of Example I. The compound has the formula:

[0022] Typical functional fluids or lubricating composition of the present invention will
contain a number of conventional additives in typical amounts as required to provide
their normal attendant functions. Such additive components and their usual ranges
are set forth below.

The foregoing composition is referred to as Base Fluid and a tractor hydraulic fluid
corresponding to the Base Fluid was evaluated for water tolerance with various additives
as set forth below. The mineral oil used in the Base Fluid had a kinematic viscosity
of 69.8 centistokes at 37.8°C and 14.5 centistokes at 98.9°C.
[0023] The test used was the International Harvester Water Tolerance Test IH BT-7; January,
1980 contained in the International Harvester Engineering Materials Specification
for Combination Hydraulic and Transmission Fluid.
[0024] The test is described as follows:
APPARATUS REQUIRED
[0025]
(1) Mechanical paint shaker, Red Devil No. 30 or equivalent.
(2) 118 ml bottle with cap.
(3) Graduated cylinder, 100 ml.
(4) 100 ml centrifuge tube according to ASTM Designation D 2273-67.
(5) Pipette or syringe capable of delivering 1.0 ml.
(6) Stopper to fit centrifuge tube.
PROCEDURE
[0026]
(1) Add 1 ml distilled.water to 99 ml hydrocarbon oil in the 118 ml-bottle.
(2) Shake the prepared sample for 5 minutes in the mechanical shaker.
(3) Transfer immediately to the 100 ml centrifuge tube.
(4) Stopper and let the agitated solutions stand undisturbed in a vertical position
for 168 hours (7 days at 70 to 80°F, 21 to 27°C), then examine for emulsion, water,
clearness and sediment.
REPORT
[0027]
(1) Level of emulsion, water and sediment to the nearest 0.1 ml.
(2) The clearness or turbidity of the solution.
EXAMPLE IV
[0028] The results of evaluations are tabulated below in the Table. The data include comparisons
with Control A, Control B and two commercially available Surfactants A (sorbitan oleate)
and B (ethoxylated fatty acid ester of sorbitol anhydride). All additives were employed
in the same Base Fluid at concentration of 1% by weight.

1. A functional fluid composition comprising a major amount of a synthetic or mineral
oil of lubricating viscosity and an amount, effective to improve the water tolerance
properties of the composition, of an oil soluble phosphite ester additive of the formula:

wherein:
R1 is alkyl or alkenyls and R2 is OH, alkoxy, oxy- alkenyl or R10 (CHxCH2O)x, in which the total number of carbon atoms in the alkyl, alkenyl, alkoxy or oxyalkenyl
groups is from 8 to 36, and x is a number representing the average number of (CH2CH2O) groups and is within the range from 2 to 4.
2. A composition according to claim 1 in which x is 2, 2.5, 3, 3.5 or 4.
3. A composition according to claim 1 or claim 2, in which R1 is alkyl having from nine to eleven carbon atoms.
4. A composition according to claim 1 or claim 2, in which R1 is alkyl having from twelve to fifteen carbon atoms.
5. A composition according to claim 1 in which the phosphite ester is
6. A composition according to claim 1 in which the phosphite ester is

and the oil is a hydrocarbon mineral oil.
7. A composition according to claim 1 in which the phosphite ester is
8. A composition according to any of claims 1 to 7, for use as a tractor fluid.
9. A composition according to any of claims 1 to 8, in which the amount of the additive
is within the range from 0.05 to 5% by weight of the oil.
10. A hydrocarbon oil composition according to any of claims 1 to 9, in which the
amount of the additive is within the range of from 0.2 to 2% by weight of the oil.