Note: Descriptions are shown in the official language in which they were submitted.
t~
6`
, BACKGROUND OF THE INVENTION
1. Field Of The Invention
,
' This invention relates to water-based hydraulic
fluids and metalwo~king compositions.
2. Prior Art
~, -
, ` In the technology of hydraulic power transmission,
; mechanical power is imparted to a fluid called "a hydraulic
fluid" in the form of pressure by means of a hydraulic pump.
Power is utilized where desired by tapping a source of said
hydraulic fluid and thus transforming,the power as pressure
back to mechanical motian by a mechanism called a hydraulic
motor. The hydraulic fluid is utilized as a pressure and
volume transmitting medium. Any'non-compressible fluid can
perform this function. Wa~er is the oldest fluid used for
this purpose and is still sometimes used alone for this
purpose. In the prior art, there has been a heavy emphasis
on the development of petroleum oils for use as hydraulic
fluids and, consequently, much o the equipment utilized
with hydraulic fluids has been designed and manufactured
; 20 specifically for use with petroleum oils. A petroleum oil
in comparison ~ith water as a hydraulic fluid possesses the
advantage of inhibiting the development of rust of the
fe.ro~s components of the mechanical equipment utilized in
,
-- 1--
~yJi~
conjunction with hydraulic fluids, (i.e., hydraulic pumps,
motors, etc.) and in preventing wear of the machinery since
the hydraulic fluid must lubricate the equipment. Petroleum
oils have a second advantage over the use of water as a
hydraulic fluid in that the petroleum oils normally exhibit
a substantially higher viscosity than water and thus con~ri-
~ bute to reduction of the leakage of ~he fluid in the mechan-
- ical equipment utilized. In addition, the technology relat-
ing to additives for petroleum oils has developed to such an
extent that the viscosity~ foam stability, wear prevention
and corrosion prevention properties of such petroleum oil
based hydraulic fluids can be further enhanced by the use of
said additives.
` Over the past 25 years, various substitutes for
petroleum oil based hydraulic fluids have been developed in
order to overcome one of the major deficiencies of petroleum
oils, namely) flam~lability. Recent interest in the use of
hydraulic fluids having up to 99% or more of water has re-
sulted from the higher cost of petroleum oils and recent
emphasis on problems of ecologically suitable disposal of
contaminated or spent petroleum oil based hydraulic fluids.
Metalworking fluids of the so-called "soluble oil"
~ype have been considered for use as hydraulic fluids. Such
fluids contain mineral oil and emulsifiers as well as various
, .
additives to increase corrosion resis~ance and irnprove anti-
wear and defoaming properties. Such fluids when used as hy-
draulic fluids are not generally suitable for use in ordinary
- industrial equipment designed specifically for use with the
petroleum oil based hydraulic fluids since such fluids do
not adequately prevent wear damage in pumps and valves of
such equipment. However, such fluids have Eound application
in specially designed, high cost, large size equipment which
because of said large size and thus inflexibility is not
suitable for use in most industrial plants. The soluble oil
hydraulic fluid usage has thus been quite limited; usage has
been largely confined to large installations where flexibil-
ity and size are not cri~ical such as in steel mills.
It is known from U. S. Patent 3~249~538 to prepare
an aqueous lubricant concentrate and lubricating composition
consisting essentially of molybdenum disulfide and a water-
soluble viscosity increasing agent such as polyvinyl alcohol
and an emulsifiable mineral oil. It is also known from U. S.
Patent 3,970,569 to prepare aqueous lubricating compositions
containing a water-soluble mixed ester obtained by trans-
est:erification of a polyoxyethylene glycol and a triglyceride.
It is also known from U. S. Patent 3,933~658 tllat a
mixture of a phosphate ester and a sulfur compound can be
used in a water-based metalworking composition to obtain
51~
extreme pressure, antiwear and corrosion inhibiting proper-
ties. Such additives are used with a suitable vehicle such
as mineral oil, vegetable oil, aliphatic acid ester, etc.
The sulfur compounds disclosed are not sulfurized molybdenum
~ compounds but rather are derivatives of 2-mercaptobenzothi-
; azole. The phosphate esters of the invention, however, are
similar to those disclosed in this reference. These are
alkylene oxide derivatives of an alkyl, aryl or arylalkyl
phosphate which are useful in the form of the free acid or
in the neutralized form wherein the phosphate ester is ~-
neutralized with a metal hydroxide or carbonate, ammonia or
; an amine. The use of these phosphate esters in water-based
metalworking fluids is suggested in ASLE Transactions 7,
pages 398 to 405, at page 405.
In no one of the references discussed above is
there any suggestion that a water-based hydraulic fluid or
metalworking lubricant can be provided by combining (1) a
water-soluble polyoxyethylated ester of an aliphatic acid or;
alcohol and (2) a sulfurized molybdenum or antimony compound
or alternatively said fluid or lubricant additionally con-
taining (3) an aliphatic, aromatic or alkyl aromatic phos-
phate ester.
_4_
~s~
. The present invention provides.a hydraulic fluid or
metal working fluid concentrate capable of imparting to water
the properties of a lubricant such as resistance to extreme pres-
sure and corrosion inhibit;.on. The concentrate oE the invention
consists essentially of:
A) a water-soluble polyoxyethylated aliphatic ester
consisting of esters of ethoxylated aliphatic monohydric and
polyhydric alcohols and ethoxylated aliphatic acids wherein the
acids have about 5 to about 20 moles of ethylene oxide added per
mole of acid and wherein the alcohols and acids have carbon chain
lengths of 8 to 36 carbon atoms and wherein the esters are produced
by first polyoxyethylating at least one of the acids or alcohols
and second obtaining the ester reaction product thereof,
B) a sulfurized metallic compound of the formula:
O ~ 5
O , ' .
_R _ 2
wherein M is molybdenum or antimony and wherein R is selected
from the group consisting of alkyl, aryl, alkylaryl radicals and
mixtures thereof having 3 to 20 carbon atoms in the alkyl group
and wherein the ratio of said water-soluble ester to the sulfurized
metallic compound is from 0.5:1 to 2:1 by weight based upon the
weight of the sulfur in the metallic compound, and optionally
C) a corrosion inhibitor, a thickener, and a mekal
deactivator.
According to a preferred embodiment, the concentrate
of the invention further contains a phosphate ester salt selected
from the group consisting of:
o o
RO-(EO)n-P-OX and R-O-(EO)n~P-(EO)n-OR
OX OX
and mixtures thereoE~ wherein EO is ethylene oxide; R is selected
from the group consisting of linear or branched chain alkyl groups
having about 6 to 30 carbon atoms or alkylaryl groups wherein the
; alkyl groups have 6 to 30 carbon atoms; X is selected from the
residue of ammonia, an amine and an alkali or alkaline earth
metal or mixtures thereof, and n is a number from 1 to 50. The
proportion of the phosphate ester to the sulfurized metallic
compound is about 0.1:1 to about 2:1 based upon the weight of the
sulfur in the rnetallic compound.
-~ The concentrates of the invention can be used when
; blended with a substantial amount of water as a flame-retardant
hydraulic fluid having excellent lubricity and antiwear charac-
teristics or as metalworking compositions used to cool and lubric-
ate surfaces which are in frictional contact such as during the
operations of turning, cutting, peeling, grinding metals and the
like. The hydraulic fluids and metalworking compositions of the
invention are ecologically superior to those fluids and metal-
working emulsions of the prior art containing mineral oil or a
~ glycol/water mixture.
; In accordance with this invention there are disclosed
hydraulic fluids, metalworking fluids and lubricating concentrates
which can be diluted with water as a base to prepare hydraulic
fluids or metalworking compositions. The disclosed compositions
provide the desirable lubricity as well as antiwear properties
which are necessary in a hydraulic fluid or a metalworking compo-
sition. The use of a phosphate_ .
~ `
__ _ __
~
ester with a combination of water, a water-soluble ester of
an oxyethylated aliphatic acid or aliphatic alcohol and a
sulfurized molybdenum or antimony compound results in hy-
draulic fluids showing synergistic improvements in perfor-
m~nce. In comparison with hydraulic fluids containing only
the water-soluble ethoxylated aliphatic ester and the sul-
furized molybdenum or antimony compound decreased wear
weight loss is obtained in use tests~ where a phosphate
ester is present as a component of the hydraulic fluid. As
is conventional in this art, corrosion inhibiting agents,
defoamers, viscosity increasing agents and metal deactivators
(chelating agents) can be utilized as part of the composi-
; tions of the invention.
The Ester Of An Ethoxylated Alipha~ic Acid or Alcohol
As an antiwear lubricant component of the lubri-
cating concentrates of the invention and of the hydraulic
fluids and metalworking additives of the invention, there
are preferably utilized water-soluble esters of the ethoxy-
lated C8-c3 6 aliphatic monohydric or polyhydric alcohols
with aliphatic acids, and aliphatic dimer acids. Such
ethoxyla~ed esters have a hydrophilic-lipophilic balance
(HLB) in the range of310 to 20. The most desirable adducts
are in the rang of 13 to 18.
-- , .
Useful ethoxylated aliphatic aeicls have about 5
to about 20 moles of ethylene oxide added per mole of acid.
Examples are ethoxylated oleic acid, ethoxylated stearic
acid and ethoxylated palmitic acid. Useful ethoxylated dimer
acids are oleic dimer acid and stearic dimer acid. Aliphatic
acids can be either branched or straight-chain and can con-
tain from about 8 to about 36 carbon atoms. Useful alipha-
tic acids include azelaic acid, sebacic acid~ dodecanedioic
acid, caprylic acid, capric acid, lauric acid, oleic acid,
stearic acid, palmitic acid and the like. Especially useful
acids for the purpose of obtaining the water-soluble esters
of this invention are aliphatic, preferably the saturated
and straight-chain, mono- and dicarboxylic acids containing
from about 8 to 18 carbon atoms.
The dimer acids employed in the formation of the
water-soluble esters employed in the aqueous lubricants of
the present invention are obtained by the polymerization of
unsaturated fatty acids having from 16 to 26 carbon a~oms,
or their ester derivatives. The polymeriza-tion of fatty
acids to form the dimer fatty acids has been described ex-
tensively in the literature and thus need not be amplified
here. The preferred dimer acids employed in the formation
of the polyester are those which have 36 carbon atoms such
as the dimer of linoleic acid and eleostearic acid. Other
dimer acids having from ~2 to 54 carbon atoms can be simi-
larly employed. The dimer acids need not be employed in
pure form and can be employed as mixtures in which the major
constituent, i.e. greater than 50~, is the dimer acid and
the remainder is unpolymerized acid or more highly poly-
merized acid such as trimer and tetramer acid.
The esters of the ethoxylated aliphatic acids and
dimer acids utilized in the hydraulic fluids and metalworking
lubricant compositions of the invention are reaction products
with the ethoxylated monohydric or polyhydric alcohols.
Useful representative monohydric alcohols are n-
octyl~ n-decyl, n-dodecyl (lauryl), n-tetra~ecyl (myristyl),
n-hexadecyl (cetyl) and n-octadecyl alcohol. Useful repre-
sentative polyhydric alcohols are ethylene glycol, diethylene
glycol, polyethylene glycol, sucrose, butanediol, butenediol,
butynediol, hexanediol and polyvinyl alcohol. Glycerol,
sorbitol, pentaerythritol, tr~methylolethane, and trimethyl-~
olpropane are particularly useul polyhydric alcohols which
can be ethoxylated and subsequently esterified to produce the
~ esters of ethoxylated aliphatic alcohvls useful as essential
components of the hydraulic flulds and metalwor~lng composi-
tions of the invention.
, .
_g_
~ ' ' , .
~LV~
Suitable monohydric aliphatic alcohols are gen-
; erally those having straight chains and carbon contents of
Ca-Cl8. The alcohols are ethoxylated so as to add about 5
moles to about 20 moles of ethylene oxide by conventional
ethoxylation procedures known to those skilled in the art.
Such procedures are carried out under pressure in the pre-
sence of alkaline catalysts. The preferred monohydric ali-
; phatic alcohols useful in producing the esters of the ethoxy-
lated aliphatic alcohols of the invention are the linear
primary alcohols having a chain length of C12- Cl 5 and sold
under the trademark "Neodol 25-3" and "Neodol 25-7" by the
Shell Chemical Company.
Representative water-soluble polyoxyethylated
esters having about 5 to about 20 moles of oxide per mol,e
are the polyoxyethylene derivatives of the following esters;
sorbLtan monooleate, sorbitan trioleate, sorbitan monostear-
ate, sorbitan tristerate~ sorbi~an monopalmitate, sorbitan t
monoisostearate, and sorbitan monolaurate.
The Sulfurized Molybdenum and Antimony Com~ounds
The sulfurized oxymolybdenum or oxyantimony organo-
phosphorodithioate additives of the invention are represtented
by the formula:
- 10- ~
5~
R \
\ P~--S M2S22
/ .,
R _ 2
wherein M is molybdenum or antimony and R is organic and is select-
ed from the group consisting of C3-C20 a]kyl, aryl, alkylaryl
radicals and mixtures thereof.
Representative useful molybdenum and antimony compounds
are sulfurized oxyantimony or oxymolybdenum organo-phosphorodi-
thioate where the organic portion is alkyl, aryl or arylalkyl and
wherein said alkyl has a chain length of 3 to 20 carbon atoms.
The Phosphate Ester Salts
The compositions of the invention may also contain a
phosphate ester salt selected from the group consisting of
O - O
RO-(EO)n-~-OX and R-O-(EO)n~P-(EO)n-OR
OX OX
and mixtures thereof wherein ethylene oxide is represented by
EO; R is selected from the group consisting of linear or branched
chain alkyl groups or alkylaryl groups wherein said alkyl groups
have about 6 to about 30 carbon atoms, preferably about 8 to about
20 carbon atoms, wherein the alkyl groups have about 6 to about 30
carbon atoms, preferably about 8 to about 18 carbon atoms and X
is selected from the group consisting of the residue of ammonia
or an amine and an alkali or alkaline earth metal or mixtures
thereof and n is a number from 1 to 50. Metals such as lithium
sodium, potassium, rubidium, cesium, calcium, strontium, and barium
are examples of X.
The phosphate ester salts utilized in the compositions
I
--11--
.~B
of the invention are those more fully disclosed in U. S. Patent
3,004,056 and U. S. Patent 3,004,057.
The phosphate esters utilized are generally obtained
by esterifying 1 mole of phosphorus pentoxide with 2 to 4.5
moles of a nonionic surface active agent obtained by condensing
at least 1 mole of ethylene oxide with 1 mole of a compound having
at least 6 carbon atoms and a reactive hydrogen atom. These no-
nionic surface active agents are well known in the art and are
generally prepared by condensing a polyglycol ether containing a
suitable number oE allcanoxy groups or a 1,2-alkylene oxlde, or -
a substituted alkylene oxide such as a substituted propylene
oxide, butylene oxide or preferably ethylene oxide with an organic
compound containing at least 6 carbon atoms and a reactive hydrogen
atom. Examples of compounds containing a reactive hydrogen atom
are alcohols, phenols, thiols, primary and secondary amines a
__.__
-12- ~
~ &~ ~
carboxylic and sulfonic acids and their amides. The amount
of alkylene oxide or equivalent condensed with a reactive
chain will generally depend upon the particular compound
employed. About 20 to 8~/o by weight of combined alkylene
oxide is generally obtained in a condensation product, how-
ever, the optimum amount of alkylene oxide or equivalent
utilized will depend upon the desired hydrophobic-lipophilic
balance desired.
Preferably, the nonionic surface active agents
utilized are derivatives of alkylated and polyalkylated
phenols, multibranched chain primary aliphatic alcohols
having the molecular configuration of an alcohol and are
produced by the Oxo process from a polyolefin of at least
7 carbon atoms or straight chain aliphatic alcohols of at
least 10 carbon ato~s. Examples of suitable nonionic surface
active agent condensation products which can be in turn ,
reacted with phosphorus pentoxide to produce the phosphate
esters utilized as additives in the hydraulic fluids of the
j invention are exemplified below~ In this list, "E0" repre-
`~ 20 sents "ethylene oxide" and the numbe-r preceding this abbre-
viation refers to the number of moles thereof reacted with
1 mole of the given reactive hydrogen-containing compo~nd.
,
`:
5~
Nonylphenol ~ 9 - 11 EØ
~onylphenol + 2 EØ
Dinonylphenol + 7 EØ
Dodecylphenol + 18 EØ
Castor oil ~ 20 EØ
Tall oil ~ 18 EØ
Oleyl alcohol + 4 EØ
Oleyl alcohol ~ 20 EØ
Lauryl alcohol ~ 4 E.Ø
.; 10 Lauryl alcohol + 15 EØ
Hexadecyl alcohol ~ 12 EØ
Hexadecyl alcohol + 20 EØ
Octadecyl alcohol + 20 EØ
Oxo tridecyl alcohol:
(From tetra~ropylene) ~ 7 EØ
(From tetrapropylene) + 10 EØ
(From tetrapropylene) ~ 15 EØ
Dodecyl mercaptan + 9 EØ
Soya bean oil amine ~ 10 EØ
Rosin amine ~ ~2 EØ
Coconut fatty acid arnine + 7 EØ
Cocoa fatty acld + 10 EØ
Dodecylbenzene sulfonamide + 10 EØ
Decyl sulfonamide + 6 EØ
. Oleic acid ~ 5 EØ -
Polypropylene glycol (~0 oxypropylene units) ~ 10 EØ
~v~
While it is known that the phosphate ester salts of theinvention, as described, can contribute to the antiwear and extreme
pressure performance characteristics oE a lubricant composition,
it has been found that a synergistic improvement in such properties
is obtained by the combination of the phosphate ester salts with
the water-soluble oxyethylated esters of the invention and the
sulfurized molybdenum or antimony compound of the invention.
It is believed that the additional lubricity and wear
preventing characteristics imparted by this synergistic combination
of additives in a water-based hydraulic fluid or metalworking com-
position is contributed by the arylalkyl or alkyl polyethoxy ethyl-
ene moieties while the phosphorus contained in the compound con-
tributes to the antiwear and extreme pressure performance of
the lubricant.
The hydraulic fluids and metalworking compositions of
the invention generally consist of about 60% to about 99% water
and about 40% to about 1% of additives. These additives can
consist of concentrates comprising combinations of the water-soluble
esters of ethoxylated aliphatic acids and monohydric and polyhydric
alcohols, molybdenum or antimony compounds, a phosphate ester, and,
in addition, can contain polymeric thickening agents, defoamers,
corrosion inhibitors and metal deactivators or chelating agents.
Preferably said fluids consist of about 75% ot 99% water and about
25% to about 1% concentrate. The fluids are easily formualted
at room temperature using distilled or deionized water although
tap water can also be used without adverse effects on the fluid
properties.
Stable concentrates of the hydraulic fluids and metal-
working compositions of the invention can be prepared. These can
be made up completely free of water as indicated below or contain
any desired amount of water but preferably contain up to 75% by
B
-
\
S~
weight of water to increase fluidity and provide ease of blending
at the point of use. These concentrates are typically diluted
with water in ~he proportion of 1:99 to 10:90.
Respresentative concentrates are as follows:
T_ble I
Inqredient ~
Polyoxyethylene 20 sorbitan 20 16 38 30 19 9
monostearate
Alkyl phosphate ester of5 4 8 6 4 2
~xample 5
Sulfurized oxymolybdenum
or antimony organo-phos-
phorodithioate at 40%
solids 15 123126 15 8
Sodium-2-mercaptobenzo-
thiazole 20 168 6 4 2
Isopropylaminoethanol or
morpholine 40 321512 8 4
Water - 20 - 20 50 75
/
-16-
The proportions of phosphate ester to sulfurized
molybdenum or antimony compound of the invention are gen-
erally about 0.1:1 to about 2:1 based upon the weight of
the sulfur in the sulfurized molybdenum or antimony compound.
The proportion of the water soluble ester of the ethoxylated
aliphatic acid or alcohol to the sulfurized molybdenurn or
sulfurized antimony containing compound is about 0.5:1 to
about 2:1 based upon the weight of the sulfur in the sulfur-
containing compound. Preferably, the proportion of phosphate
ester to sulfurized molybdenum or antimony compound is 0.5:1
to 1:1 and, preferably, the proportion of the ester of the
ethoxylated aliphatic acid or alcohol ~o the sulfurized
molybdenum compound is about 1:1 to about 1.5:1.
The concentration of sulfurized molybdenum or
antimony compound to water in the hydraulic fluid or metal-
working compositions of the invention is generally about
o.o5~ to about ~ by weight and the concentration of the
phosphate ester to water in the hydraulic fluid or metal-
working compositions of the invPntion is generally about 0~5~
to about 1~ by weight. The concentration of the water-soluble
ester of the ethoxyLated aliphatic acid or alcohol to water
in the hydraulic fluid or metalworking compositions of the
invention is generally about O.loto to about 5% by weight.
Preferably, these proportions by weight are respectively 0.75
to 0.5~, 0.250to to 0. to~ and 1% to 20to.
-17-
The thickeners, metal deactivators and corrosion
inhibitors which can be added either to the conc~ntrate or
to the hydraulic fluid or metalworking compositi;ons of the
invention are as follows:
Liquid-Vapor Phase Corrosion Inhibitors
The liquid-vapor corrosion inhibitor can be any of
the alkali metal nitrites, nitrates and benzoates. Certain
amines are also useful. The inhibitors can be used individ-
ually or in combinations. Representative examples of the
preferred alkali metal nitrates and benzoates which are use-
ful are as follows: sodium nitrate, potassium nitrate,
calcium nitrate, barium nitrate, lithium nitrate, strontium
nitrate, sodi~ benzoate, potassium benzoate, calcium benzoate,
barium benzoate, lithium benzoate and strontium benzoate.
Representative amine type corrosion inhibitors are
morpholine, N-methylmorpholine, N-ethylmorpholine, ethylene-
diamine, dimethylaminopropylamine, N,~-dimethylethanolamine,
alpha- and gamma- picoline, piperazine and isopropylamino-
ethanol.
Particularly preferred vapor phase corrosion in-
hibi.ting compounds are morpholine and isopropylaminoethanol.
. As corrosion inhibitors, a p~-oportion of from about 0.05~ ~o
about 2~ by weight is used based upon the total weight o~ the
hydraulic fluid or metalworkin~ compos ition of the invention.
Preferably, about 0.5~ to about 2C~o by weight of these amines
are used.
-]8-
~6~8~
,
Metal Deactivators (Chelating ~ents)
The metal deactivato:rs are used primarily to
chelate copper and copper alloys. Such materials are well
known in the art and individual compounds can be selected
from the broad classes of materials useful for this purpose
such as the various triazoles and thiazoles as well as the
amine derivatives of salicylidenes. Representative specific
examples of these metal deactivators are as follows: ben-
zotriazole, tolytriazoie~ ~-mercaptobenzothiazole, sodium
2 mercaptobenzothiazole, and N,N'-disalicylidene-1,2-pro-
panediamine.
It is also contemplated to add other known corro-
¦ sion inhibitors. Besides the amines, alkali metal nitrates,
ben2oates and nitrites listed above, the alkoxylated fatty
acids are useful as corrosion inhibitors.
The Thickener
Depending upon the anticipated conditions of use,
it may be desirable to utilize in the hydraulic fluid and
metalworking compositions of the invention a thickener. The
thickener can be of the polyglycol type. Such thickeners are
well known in the art and this type thickener is the preferred
thickener since it has particular advantages from the sta~ld- ;
point of providing Newtonian viscosity characteristics under
varying shear conditions. The polyglycol thickeners are
polyoxyalkylene polyols prepared by reacting an alkylene oxide
-19- . ,
~,
S~
with a linear or branched chain polyhydric alcohol. These
polyols contain ethylene oxide and propylene oxide in a
mole ratio of between about 100:0 to about 70:30 ethylene
oxide~propylene oxide. These thickeners are commercially
available and sold under the trademark "Ucon 75H-90,000" by
Union Carbide and Carbon Chemical Corporation. The specifi-
cations for this material call for a pour point of 40 F., a
- 1ash point of ~85 F., a specific gravity at 20 C. of 1.95
and a viscosity of about 90,000 S.U.S. at a-temperature of
100 F. Generally, about 2~o to about 20~ is used based upon
the total weight of the hydraulic fluid or metalworking
additive composition of the invention, preferably, about 5
to about 15% of polyglycol thickener is used.
Other types of viscosity increasing agents can be
used in the hydraulic fluid and metalworkin~ compositions of
the invention such as polyvinyl alcohol, polymerization pro-
ducts of acrylic acid a~d methacrylic acid, polyvinyl pyrrol-
idone polyvinyl ether maleic anhydride copolymer and sorbitol.
These materials are well known in the art and are utilized
in varying proportions depending upon the des~red viscosity
and the efficiency of the thickening or viscosity incre2sing
effect. Generally, about 3~ to about 15~o of such thickcners
will provide a desi.red viscosity of about 100 S.U.S. at 100F~
in the hydraulic fluid or metal~orking COrilpOS~ tion of the
-20-
.
invention. ~ the use of such thickening agents, it is
believed that the hydraulic fluids of the invention can be
used in hydraulic pumps and other equipment without signifi-
cant wear resulting from cavitation erfects and use of such
thickeners also substantially prevents internal and external
leakage in the mechanical parts of the hydraulic system
during the pumping of such hydraulic fluids.
The phosphate ester and the esters of ethoxylated
aliphatic acids and monohydric and polyhydric alcohols, as
described above, are water-soluble in the sense that no
special method is required to disperse these materials in
` water and keep them in suspension over long periods of time.
The sulfurized molybdenum or antimony compounds on the other
hand are insoluble in water and require emulsificatio~ prior
to use, for instance, with anionic or nonionic surfac~ants.
Useful representative anionic or nonionic surfactants are:
sodlum petroleum sulfonate, i.e. sodium dodecylbenzene sul-
fonate; polyoxyethylated fatty alcohol or fatty acid and
polyoxyethylated alkyl phenol.
A typical recipe for the emulsification of the sul-
furized molybdenum or antimony compound of the invention
(sulfurized oxymolybdenum or oxyantimony organo-phosphoro-
dithioates) is as follows:
-21-
,
' .
Emulsiier % b~ welght
Sodium dodec~lbenzene sulfon~te 7Q
Eth~leIle gl~coL mon~but~l ether 23
Butyl alcohol 7
L00
Lmulsifiable Concentrate (hereater termed emulsion)
_ .
Sulfurized molybdenum o~
antimony com~ound 40
Emulsiier 60
lao
A typical high water-base hydraulic 1uid o~ metal-
working additive o the invention will contain the components
shown in Table II.
! Table II
TYPICAL COMPOSITIO~ OF HYDRAULIC
FLUID_OR ME~LWORKING ADDITIVE
Com~onent ~ by weight
Water (distilled or deionized) 95-70
Polymeric thickener 0-15
20 . Water-soluble ethoxylated ester 3-10
Molybdenum or antimony compound
at 40 % solids 1-5
Water-soluble alkyl phosphate
ester 0.1-1.0
Metal deactivator 0.1-0.5
Corrosion inhibitor 0.5-1.0
_
~ I .
The hydraulic fluid and metalworking compositions
of the invention, when formulated as above, are transparent
liquids having a viscosity of up to 400 S.U.S. at 100 F.,
which are stable over long periods of storage at ambient
temperature. In addition~ the hydraulic fluids and metal-
working additives of the invention are oil-free and will not
support combustion in contrast to those flame-resistant
fluids of the prior art based upon a glycol and water or
petroleum oils. The hydraulic fluids and metalworking addi-
tives of the invention are ecologically clean and non-
polluting compositions when compared to existing petroleum-
based hydraulic fluids. Since the hydraulic fluids and
metalworking additives of the invention are largely based
upon synthetic materials which are not derived from petro-
leum, the production of such fluids is relatively independent
of shortages of petroleum oil and not materially influenced
by the economic impact of such shortages.
The hydraulic fluids of the invention can be used
in various applications requiring hydraulic pressures in the
range of 200-2,000 pounds per square inch since they have
all the essential properties required such as lubricity,
viscosity and corrosion protection. The hydraulic fluids of
the invention are suitable for use in various types of hy-
draulic systems and are especially useful in systems in which
.:
.
-2~- I s
'
::
~ 4
vane-type pun~ps or the axial-pis~on pumps are used. Such
pumps are used in hydraulic systems where pressure is re
quired for molding, clamping, pressing metalsJ actuating
devices such as doors, elevators, and other machinery or for
closing dies in die-casting machines and in injection molding
equipment and other applications.
In evaluating the hydraulic fluids of the inven-
tion, a test generally referred to as the Vickers Vane Pump
Test is employed. The apparatus used in this test is a hy-
draulic system which functions as follows: Hydraulic fluid
is drawn from a closed sump to the intake side of a Vickers
V-104C vane-type pump. The pump is driven by, and directly
coupled to, a twenty-five horsepower, 1740 r.p.m. electric
motor. The fluid is discharged from the pump through a
- O pressure regulating valve. From there it passes through a
calibrated venturi (used to measure flow rate) and back to
the sump. ~ooling of the fluid is accomplished by a heat
exchanger through which cold water is circulated. No exter-
nal heat is required; the fluid temperature being raised by
the frictional heat resulting from the pump's work on the
-- fluid. Excess heat is removed by passing the fluid through
the heat exchanger prior to return to the sump. The Vickers
V-104C vane-type pump comprises a cylindrical enclosure (the
pump body) in which there is housed a so-called "pump
,;' ' ' .
-2~
s~
cartridge". The "pump cartridge" assembly consists of front
and rear circular, bronze bushings, a -rotor, a cam-ring and
rectangular vanes. The bushings and cam-ring are supported
by the body of the pump and the rotor is connected to a
shaft which is turned by an electric motor. A plurality of
removahle vanes are inserted into slots in the periphery of
the rotor. The cam-ring encircles the rotor and the rotor
and vanes are enclosed by the cam-ring and the bushings.
The inner surface of the cam-ring is cam-shaped. Turning
t~e rotor results in a change in displacement of each cavity
enclosed by the rotor, the cam-ring, two adjacent vanes and
the bushings. The body is ported to allow fluid to enter
and leave the cavity as rotation occurs.
The Vickers Vane Pump Test procedure used herein
specifically requires charging the system with 5 gallons of
the ~est fluid and running at temperatures ranging from 100
to 1~5 F. at 750 to 1000 p.s.i. pump discharge pressure
(load). Wear data were made by weighing the cam-ring and
the vanes of the "pump cartridge" before and after the test.
At the conclusion of the test run and upon disassembly for
weighing, visual examination of the system was made for
signs of deposits, varnish, corrosion, etc.
' `` `
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~ 58 1L~
The following examples more fully describe the
hydraulic fluids of the invention and show the unexpected
results obtained by their use. The examples are intended
for the purpose of illustration and are not to be construed
as limiting in any way. All parts and percentages are by
weight and all temperatures are in degrees centigrade unless
otherwise noted.
EXAMPLE 1 (Comparative Example)
Formin~ no part of this invention.
A comparative hydraulic fluid representing the best
available water-based hydraulic fluid of the prior art was ~!
prepared by mixing 10~ of a water-soluble polyoxyethylene
ester of sorbitan monostearate having 20 moles of ethylene
oxide per mole of ester and sold under the trademark "EMSORB
6905" by Emery Industries with 12% of a polyglycol thickener,
sold under the trademar~ "PLURACOL V-lO" by the BASF Wyandotte
Corporation. Morpholine in the amount of l~ was added as a
_,
vapor-phase corrosion inhibitor together with 1.8~ o~ the
triethanolamine salt of 2-mercaptobenzothiazole. The salt
was prepared by reacting 5 parts of triethanolamine with 1 -?
part of 2-mercaptoben2othia~ole. The balance of the composi-
tion was deionized water. The fluid was clear in appearance
and had a viscosity of 140-150 S.U.S. at 100 F. W~en tested
according to the procedure descri~ed above in ~he Vickers
.
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~ .
.
s~ '
~ ~ 5~ ~ ~
V-104C vane pump for a period of 20 hours under a 750 pounds
per square inch load at 100~ F. and 1200 r.p.m. speed, the
total weight loss was found to be 848 milligrams.
EXAMP~E 2
A water-based hydraulic fluid of the invention was
; prepared by blending 10~ of a water-soluble polyoxyethylene
ester of sorbitan monostearate, sold under the tràdemark
"EMSORB 6905", with 12~ of a polyglcol thickener, sold under
the trademark "PLURACOL V-10". To this mixture there was
added 1% morpholine and 1.8~ of the triethanolamine salt of
Z-mercaptobenzothiazole prepared as in Example 1. There was
then added 2% of a 40~ solids emulsion of a sulfurized oxy-
molybdenum-organophosphorodithioate, sold under the trademark
"VANLUBE 723" by the R. T. Vanderbilt Company. The balance
of the composition was deionized water. The fluid had a
~; viscosity of about 145 S.U.S. at 100 F. and was clear~ amber
colored and was tested in the Vickers V-104C Vane Pump Test,
as described above, for a period of 20 hours a~ 750 pounds
per square inch load at 100 F., and 1200 r.p.m. speed. Test
results were obtained indicating a total wear weight loss of
566 milligrams.
~; EXAMPLE
.
A water-based hydraulic fluid was prepared by
mixing 10% of a water-soluble polyoxyethylene ester of
,
27-
, .
5 ~ ~ ~
sorbitan monostearate, sold ~mder the trademark "EMSO~B
6905", 2~ of a 40~ solids emulsion of a sulfuriæed oxy-
molybdenum-organophosphorodithioate, sold under the trademark
"VANLUBE 72~" and 0.5~ of a straight chain alkyl phosphate
ester, sold under the trademark "ANTARA LB-400" with 12% of
a polyglycol thickener sold under the trademark "PLURACOL
V-10". To this mixture there w~s added 1~ of morpholine
and 1.8% of the triethanolamine salt of 2-mercaptobenzothi-
azole as liquid-vapor corrosion inhibitors; the preparation
of said triethanolamine salt of 2-mercaptobenzothiazole
being described in Example 1. The hydraulic fluid obtained
had a viscosity of about 145 S.U.S. at 100 F. and was clear
and amber colored. When tested in the Vickers V-104C Vane
__
Pump Test, this fluid afforded excellent wear performance.
- Under performance testing at conditions of 750 pounds per
square inch load at 100 F. and 1200 r.p.m. speed over a
period of 20 hours, the unexpected excellent wear loss re-
sult of 117 milligrams was obtained. In a second test of
C' the same hydraulic fluid, at 1000 pounds per square inch
~` 20 load, the wear weight loss was 120 milligrams.
~QMPJ.E 4
The fluid of Example 3 was diluted with deionized
water using 1 part of water ,o 4 parts of the hydraulic fluid
of Example 3. A clear fluid was obtained which had a
.
28-
viscosity of about 85 S.U.S. at 100 F. and when evaluated
in the Vickers Vane Pump under the test conditions described
above using a 750 pounds per square inch load at 100 F.,
1200 r.p.m. speed and 20 hours test time, a wear loss of
134 milligrams was obtained.
Comparative performance of the hydraulic fluids
prepared in Examples 1-4 is presented in Table III below.
As indicated in Table III, the hydraulic fluid of ~xample 2
provides a marked improvement over the results obtained for
the fluid o~ Example 1 but upon the addition of the phosphate
ester to the fluid of Example 2 a completely disproportionate
reduction in wear weight loss is obtained which improvement
is substantially retained where the composition of Example 3
is diluted with 20~ additional water (Example 4).
EXAMPLE III
VICKERS V~NE PUMP WEAR RESULTS WITH
HYDRAULIC FLUIDS OF INVENTION
Wear Weight Loss -~
ydraulic Fluid Example No.1 (m~.) Total
1 (Comparative Example) 848
` 2 566
3 117
l~ 134
,
; 1. Conditions: Vickers Vane Pump, V-104C~ 20
hours running time, 750 p.s.i.
load at 100F., 1200 r.p.m. speed.
.
29
5~
E~A~PLE 5
A water-based hydraulic fluid was prepared by
blending 5% of an ester of polyoxyalkylated sorbitan mono-
~e3~ate sold under the trademark "EMSORB 6905", o.8~ of a
40~ solids emulsion of a sulfurized ox~nolybdenum-organo-
phosphorodithioate sold under the trademark "MOLYVAN L"
by the R. T. Vanderbuilt Company which was emulsified in
water using 1.2% of a 1:1 blend of the nonionic surfactants
sold under the trademark PLURAFAC D-25 and PLURAFAC A-24 by
the BASF Wyandotte Corporation and 0.5~ of an alkyl phosphate -
ester obtained by the reaction of 2 moles of phosphorus pen-
toxide with the surface active agent condensation product
obtained by reacting 1 mole of oleyl alcohol and 4 moles of
ethylene oxide. In addition 12~ of a polyglycol thickener
sold under the trademark "PLURACOL V-10" and 1.8% of the
triethanolamine salt of 2-mercaptobenzothiazole and 1% mor-
. .
pholine were added as corrosion inhibitor and metal deacti-
`~ yator ~chelating agent) respectively. The balance o the
fluid i~ deionized water. The fluid obtained had a viscosity
of 125 SOU.S. at 100 F. and was clear and amber in color.
- Upon evaluation in the Vickers Vane ~ump Test under conditior.ç
~ of 700 pounds per square inch load, 1200 r.p.m. speed; the
; test being allowed to run for 20 hours and the hydraulic
fluid being maintained at .he te~perature o 100 F., the
wear loss obtained was 146 miiligr~ms.
-
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EX~MPI,E 6
A water-based hydraulic fluid was prepared by
blending 15~ of the ester of polyoxyalkylated sorbitan
monostearate sold under the trademark "EMSORB 6905", 2~ of
the 40~ solids emulsion o~ sulfurized oxymolybdenum-organo-
phosphorodithioate of Example 5 and 0.5~ of the phosphate
ester utilized in Example 5. In addition to these ingredients,
8% of a polyglycol -thickener sold under the trademark "PLUR-
ACOL V-10" was added together with a blend of 1.8~ of the
triethanolamine salt of 2-mercaptobenzothiazole and 10~
morpholine as corrosion inhibitor and metal deactivator com-
` ponents. The fluid had a viscosity of about 95 S.U.S. at
~ 100 F. and was clear an.d amber in color. Upon evaluation
:. in the Vickers Vane Pump Test according to the procedure of
` - Example 5, test results indicated 18~ milligrams of wear loss.""
, EXAMPLE 7
`. A water-based hydraulic fl~lid was prepared similar
in composition to that prepared in Example 6 except that~
: of the 40~ solids emulsion of the sulfurized oxymolybdenum-
''
: 20 organophosphorodithioate described in Example 5 was utilized
together with 1~ of the phosphate ester described in Example
:: i
5. In addition to these components, there were added 8~ of
a polyglycol thickener sold under the trademark "PLURACOL
~:~ V-10" and the corrosion inhi~itor and metal deactivator
-31-
blend as described in Example 5. The fluid was clear, had
a viscosity of 90-100 S.U.S. and test results indicated 164
milligrams of wear loss upon evaluation in the Vickers Vane
Pump Test where the specific conditions of the test were 750
pounds per square inch load, 100 F., 1200 r.p.m. and 20
hou~s running time.
,-- EXAMPLE 8
A water-based hydraulic fluid was prepared by
blending 1.9~ of the ester of polyoxyalkylated sorbi~an
monooleate sold under the trademark "EMSORB 6905", 1.55~ ~ -
4D~ solids emulsion of a sulfurized oxymolybdenum-organo-
phosphorodithioate together with 0.4% of the phosphate ester
utilized in Example 7. In addition 14~ of a polyglycol
thickener sold under the trademark "PLURACOL V-10" was in-
corporated together with 0.75% o~ mixed isopropylaminoethanol
- and 0.4% sodium-2-mercaptobenzothiazole as corrosion inhibitor
and metal deactivator. The balance of the fluid was water.
The hydraulic fluid appeared clearJ amber in color and had a
viscosity of 100 S.U.S. at loo F. Test results indicated
211 milligrams wear loss on evaluation by the above described
Vickers Vane Pump Test at the conditions o~ 20 hours, 750
pounds square inch pressure load at 1200 r.p.m. and 100 F.
- ;
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~p .
EXAMPLE ~
A water-based hydraulic fluid was prepared based
upon the same composition of Example 8, with the exception
of the omission of the thickener. This fluid had a viscosity
of less than 32 S.U.S. at 100 F., but still gave good per-
formance as indicated by 242 milligrams wear loss in the
Vickers Vane Pump Test under the same conditions as in
Example 8.
EXAMPLES 10 and 11
Two water-based hydraulic fluids were prepared based
upon one fifth of the same active components as in Example 8,
with 14~ thickener and without thickener. These fluids were
tested under the same test conditions in the Vickers Vane
Pump Test method described above and good performance was
obtained with both fluids. Wi~h the thickened fluid which
had a viscosity of 100 S.U.S. at 100 F., 289 milligrams
weight loss was obtained in 20 hours~ With the unthickened
; fluid, 295 milligrams weight loss was obtained in a similar
length of time,
EXAMPLES 12-15
- Examples 2 and 3 are repeated substituting in each
example a sulfurized oxyantimony-organophosphorodithioate
sold under the trademarks "VANLUBE 622 and VANLUBE 648" for
- the sulfurized molybde~um compound used in Examples 2 and
Satisfactory hydraulic fluid properties are obtained.
-~3-
EXAM~'LE 16
A hydraulic fluid concentrate was prepared having
the composition, in percent by weight of:
polyoxyethylene 20
sorbitan monostearate ~8
- alkyl phosphate ester of
Example 5 8
sulfurized oxymolybdenum
organophosphorodithioate
- at 40% solids 31
sodium-2-mercaptobenzothiazole 8
isopropylaminoetha~ol 15
The fluid was clear , dark amber in color, free
flowing and showed no phase separation after aging at room
.. . . .
temperature for 6 months. Upon diluting the concentrate
with tap water to obtain hydraulic fluids containing 93 1/2
water, 95~ water, 97% water and 9g~0 water,homogeneous mix-
- tures were obtained which when tested in the Vickers Vane
~, .
~ Pump in accordance with the test procedure described above
, " , ~
~ _ and in Example 1 gave total wear weight losses of less than
250 milligrams.
While this invention has been described with
reference to certain specific embodiments, it will be
recogni2ed by those skilled in the art tha~ ma.,y variat~ons
are possible without depar~ing from the scope and spirit of
the invention.
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