Note: Descriptions are shown in the official language in which they were submitted.
WATER-BASED, SYNERGISTICALLY-THICKENED HYDRAULIC FLUID
Background of the Invention
1. Field of the Invention
This invention relates to water-based hydraulic
fluids and metalworking composi~ions.
2. Prior Art
In the technology of hydraulic power transmission,
mechanical power is imparted to a fluid called 'ia hydraulic
fluid" in the form of pressure by means of a hydraulic pump.
Power is utili~ed where desired by tapping a source of said
hydraulic fluid and thus transforming the power as pressure
back to mechanical motion 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. Water 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 of the equipment utilized with hy-
draulic fluids has been designed and manufactured specifically
for use with petroleum oils. A petroleum oil in comparison
with water as a hydraulic fluid possesses the advantage of
inhibiting the development of rust of the ferrous components
of the mechanical equipment utili~ed in conjunction with
hydraulic fluids, li-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
3 ~3~
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 contribute to reduction of the
leakage of the fluid in the mechanical equipment utilized. In
addition, the technology relating 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, flammability. Recent interest in the use of
hydraulic fluids having up to 99 percent or more of water has
resulted from the higher C05t of petroleum oils and recent
emphasis on problems of ecologically suitable disposal of
contamina~ed or spent petroleum oil based hydraulic fluids.
Metalworking fluids of the so-called "soluble oil"
type have been considered for use as hydraulic fluids. Such
fluids contain mineral oil and emulsifiers as well as various
additives to increase corrosion resistance and improve anti-
wear and defoaming properties. Such fluids when used as
hydraulic 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 found
` `` ~.~63~
application in specially designed, high cost, large size
equipment which, because of said large size and thus in-
flexibility, 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 flexibility and size are not critical such
as in steel mills.
It is known from U.5. Patent No. 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 No. 3,970,5~9 to prepare aqueous lubricating
compositions containing a water-soluble mixed ester obtained
by transesterification of a polyoxylethylene glycol and a
triglyceride.
~ It is also known from U.S. Patent No. 3,933,65B that
-~ a mixture of a phosphate ester and a sulfur compound can be
- used in a water-based metalworking composition to obtain
extreme pressure~ antiwear and corrosion inhibiting properties.
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-mercaptobenzo-
thiazole. 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
i ~ ~3~
phosphate which are useful in the form of the free acid or in
the neutralized for 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.
It is also known from U.S. Patent No. 4,151,099 and
U.S. 4,138,346 to prepare water-based hydraulic fluids and
metalworking lubricants. These hydraulic fluids which contain
a phosphate ester and a sulfur compound or alternatively a
phosphate ester, a sulfur compound and a water-soluble poly-
oxyethylated aliphatic ester are optionally thickened with a
polyglycol thickener but there is no suggestion in these
references, or in any of the references above, that such
fluids can be provided by the utilization of an alpha-olefin
; epoxide-modified polyether polyol thickener which reacts
synergistically with certain components of the hydraulic
fluid, particularly the phosphate ester or the phosphate ester
and amine components to provide greatly increased viscosity in
~he resultant fluidso
Summar~ of the Invention
This invention relates to thickened high-viscosity,
water-based hydraulic fluids and metalworking fluids. Said
fluids comprise a water-soluble polyoxyethylated aliphatic
ester, a sulfurized metallic compound, a phosphate ester salt,
and a polyether polyol thickening agent. Optionally, the
fluids of the invention can include a corrosion inhibitor and
_~ _
~ ~ ~3~ 1
a metal deactlvator. The use of a polyether polyol (poly-
ether) thickening agent having a molecular weigh-t oE abou-t
1000 -to about ~5,000, preferably about 1000 -to about 10,000,
derived from the reaction oE ethylene oxide or e-thylene oxide
and at least one lower alkylene oxide haviny 3 to 4 carbon
a-toms with an active hydrogen-containing inltiator having no
more than one ac-tive hydrogen and further modified by reaction
with an alpha-olefin epoxide (oxide) having about 12 to about
18 carbon atoms, unexpectedly provides a surprising increase
in viscosity.
~ l-ternatively, the modified polyether polyol
thickening agents can be obtained by copolymerizing a m:ixture
of ethylene oxide, a-t least one other lower alkylene oxide
having 3 to ~ carbon atoms, and an alpha-olefin expoxide having
about I2 to about 18 carbon atoms, or mixtures thereof.
The concentrates of the invention can be used when
blended with a substantial amount oE water as a flame-retardant
hydraulic fluid having excellent lubricity and antiwear charac-
teristics or as metalworking compositions used to cool and
lubricate surfaces which are in fri.ctional contact such as
during the operations of turning, cutting, peeling, grinding
metals and the like. The hydraulic fluids and metalworking com-
positions of the invention are ecologically superior to those
fluids and metalworking emulsions of the prior ar-t containing
mineral oil or a glycol/water mixture.
Detailed Description oE the Invention
and the Preferred Embodiments
In accordance with this invention, there are
disclosed hydraulic fluids, metalworking fluids and lubri-
cating concentrates which can be diluted with water as abase to prepare hydraulic fluids or metalworking composi-tions.
The disclosed composi-tions provide -the desirable lubricity as
- 5 -
1 1 ~3~ 1
well as antiwear properties which are necessary in a
hydraulic
3~ 1
fluid or a metalworking composition. The thickened hydraulicfluids and metalworking fluids of the invention can be pre-
pared at such viscosities as to substantially prevent internal
and external leakage in the mechanical parts of a hydraulic
system during the pumping of such hydraulic fluids and where
the fluids are utilized as metalworking fluids, the thickened
fluids reduce spattering of the fluids which can occur under
high speed metalworking operations. As is conventional in
this art, corrosion inhibiting agents, defoamers, metal
deactivators (chelating agents) can be used as part of the
compositions of the invention.
The Ester of an Ethoxylated Aliphatic 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 ethoxylated
Cg-C36 aliphatic monohydric or polyhydric alcohols with
aliphatic acids, and aliphatic dimer acids. Such ethoxylated
esters have a hydrophilic-lipophilic balance (HLB) in the
range of 10 to 20. The most desirable adducts are in the
range of 13 to 18.
Useful ethoxylated aliphatic acids 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 contain from
--6--
` ;
`3 ~ ~0~ 1
about 8 to about 36 carbon atoms. Useful aliphatic 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 for the
purpose of obtaining the water-soluble esters of this inven-
tion 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 atoms, or
their ester derivatives. The polymerization of fatty acids to
form the dimer fatty acids has been described extensively in
the literature and thus need not be amplified here. The
preferred dimer acids employed in the formation of the poly~
ester are those which have 36 carbon atoms such as the dimer
of linoleic acid and eleostearic acid. Other dimer acids
having from 32 to 54 carbon atoms can be similarly 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 percent, is the dimer acid and the remainder
is unpolymerized acid or more highly polymerized 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.
~3~
Useful representative monohydric alcohols are
n-octyl, n~decyl, n-dodecyl (lauryl), n-tetradecyl (myristyl~,
n-hexadecyl (cetyl) and n-octadecyl alcohol. Useful represen-
tative polyhydric alcohols are ethylene glycol, diethylene
glycol, polyethylene glycol, sucrose, butanediol, butenediol,
butynediol, hexanediol and polyvinyl alcohol. Glycerol,
sorbitol, pentaerythritol, trimethylolethane, and trimethylol-
propane are particularly useful polyhydric alcohols which can
be ethoxylated and subsequently esterified to produce the
esters of e~hoxylated aliphatic alcohols useful as essential
components of the hydraulic fluids and metalworking composi-
tions of the invention.
Suitable monohydric aliphatic alcohols are generally
those having straight chains and carbon contents of Cg-C~g.
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 presence of alkaline
; catalysts. The preferred monohydric aliphatic alcohols useful
in producing the esters of the ethoxylated aliphatic alcohols
of the invention are the linear primary alcohols having a
chain length of C12-C1s 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 mole are the
` polyoxyethylene derivatives of the following esters; sorbitan
monooleate, sorbitan trioleate, sorbitan monostearate,
~ 1 630~ ~
sorbitan tri.stearate, sorbitan mon.opalmi:tate, sorbitan mono-
isostearate, and sorbitan. monola.urate..
Sulu~ d Molybdenum a~Antimony Compounds
The sulfurized oxymolyddenum.or oxiantimony organo-
phosphorodithioate additi.ves of the invention are represented._
.
~ 1 63~4~
,,
by the formula:
I R\
\O S I
,, \P~ S I M2S202
O
R / _12
wherein M is molybdenum or antimony and R is organi-~ and is
selected from the group consisting of C3-C20 alkyl, aryl,
alkylaryl radicals and mixtures thereof.
Representativ~ useul molybdenum and antimony
compounds are sulfurized oxyantimony or oxymolybdenum organo-
phosphorodithioate 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 Esters
~ he compositions of the invention contain a phos-
phate ester salt selected rom the group consisting of
.. ... _ . . ..
~ ~ ~3~
o o
1~ 11 J
RO--(EO~n--P----OX and ~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 con-
sisting of the residue of ammonia or an amine and an aIkali or
alkaline earth metal or mixtures thereof and n is a number
from 1 to 50. Metals such as lithium, sodium, potassium,
ribidium, cesium, calcium, strontium, and barium are examples
of X.
The phosphate ester salt composition utilized in the
compositions of the invention are those more fully disclosed
in U.S. Patent No. 3,004,056 and U.S. Patent No. 3,004,057,
The phosphate esters utilized are génerally obtained
by esteriying 1 mole of phosphorus pentoxide with 2 to 4.5
moles of a nonionic surface active agent obtained by con-
densing at least 1 mole of ethylene oxide with 1 mole of a
compound having at least 6 carbon atoms and a reactive hydro-
gen atom. These nonionic sur~ace active agents are well known
3~
in the art and are generally prepared by condensing a poly-
glycol ether containing a suitable number of alkanoxy groups
or a 1,2-alkylene oxider 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 and 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 85 percent by weight of combined alkylene oxide is
generally obtained in a condensation product, however, 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
atoms. Examples of suitable nonionic surface active agent
condensation products which can be in turn reacted with phos-
phorus pentoxide to produce the phosphate esters utilized as
additives in the hydraulic fluids of the invention are exem-
plified below. In this list, "EO" represents "ethylene oxide"
and the number preceding this abbreviation refers to the
-12-
~ ~ ~3~ ~
number of moles thereof reacted with 1 mole of the given
reactive hydrogen-containing compound.
Nonylphenol + 9 - 11 EO
Nonylphenol + 2 EO
Dinonylphenol + 7 EO
Dodecylphenol + 18 EO
Castor oil + ~0 EO
Tall oil + 18 EO
Oleyl alcohol + 4 EO
Oleyl alcohol + 20 EO
- Lauryl alcohol + 4 EO
Lauryl alcohol + 15 EO
Hexadecyl alcohol + 12 EO
Hexadecyl alcohol + 20 EO
Octadecyl alcohol + 20 EO
Oxo tridecyl alcohol:
(From tetrapropylene) + 7 EO
(From tetrapropylene) + 10 EO
(From tetrapropylene) + 15 EO
Dodecyl mercaptan + 9 EO
Soya bean oil amine + 10 EO
Rosin amine + 32 EO
Coconut fatty acid amine + 7 EO
Cocoa fatty acid + 10 EO
Dodecylbenzene sulfonamide + 10 EO
Decyl sulfonamide + 6 EO
Oleic acid + 5 EO
Polypropylene glycol (30 oxypropylene units) + 10 EO
-13-
The hydraulic fluids and metalworking compositions
of the invention generally consist of about 60 percent to
about 99 percen~ water and about 40 percent to about 1
percent of additives. These additives can consist of concen-
trateS comprising combinations of the water-soluble esters of
ethoxylated aliphatic acids and monohydric and polyhydric
aliphatic alcohols, molybdenum or antimony compounds, a
phosphate ester, and, in addition, can contain polymer
thickening agents, defoamers, corrosion inhibitors and metal
deactivatrs or chelating agents. Preferably, said fluids
consist of about 75 percent to 99 percent water and about 25
percent to about 1 percent concentrate. The fluids are easily
formulated 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
metalworking compositions of the invention can be prepared.
These can be completely free of water as indicated below or
contain any desired amount of water but preferably contain up
to 75 percent by weight of water to increase fluidity and
provide ease of blending at the point of use. These concen-
trates are typically diluted with water in the proportion of
1:99 to 10:90.
Representative concentrates are as follows:
_l ~_
~ ~3~
Table I
Hydraulic Fluid Concentrates
Ingredient % by Weight
Thickener o Example 4 50.0 50.0 50.0
Alkylphosphate ester of Example 1 2.94 4.55 4.0
Polyoxye~hylene 20 sorbitan
monostearate 11.75 18.17 19.0
Sulfurized oxymolybdenum or antimony
organophosphorodithioate at
40~ solids 8.83 13.64 15.5
Sodium-2-mercaptobenzothiazole 11.77 6.Q6 4.0
Morpholine 14.71 7.58 7.5
100.00 1aO.00 100.00
The proportions of phosphate ester to sulfurized
molybdenum or antimony compound of the invention are generally
about 0.1:1 to about 2:1 based upon the weight of the sulfur
in the sulfurized molybdenum or antimony compounds. The
proportion of the water-soluble ester of the ethoxylated
aliphatic acid or alcohol to the sulfurized molybdenum 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 to 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.D5
-15-
~ ~ 63~ ~
percent to about 3 percent by weight and the concentration of
the phosphate ester to water in the hydraulic fluid or metal-
working compositions of the invention is generally about 0.05
percent to about l percent by weightO 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 0.1 percent
to about 5 percent by weight. Preferably, these proportions
by weight are respectively 0.75 percent to 0.5 percent, 0.25
percent to 0.5 percent, and 1 percent to 2 percent.
The Alpha-Olefin Epoxide Modified
Polyether Polyol Thic_ening A~ent
The modified polyether polyol thickening agents
utilized to thicken the hydraulic fluids and metal-working
fluids of the invention can be obtained by modifying a
polyether polyol thickening agent derived from the reaction of
ethylene oxide or ethylene oxide and at least one lower
alkylene oxide having 3 to 4 carbon atoms with at least one
active hydrogen-containing aliphatic or alkylaromatic initiator
compound containing no more than one active hydrogen and 12 to
18 aliphatic carbon atoms. Useful initiators are selected
from the group consisting of alkane monoalcohols, alkene
monoalcohols, and alkyne monoalcohols. Specific examples of
initiators include dodecylphenol, dodecylalcohol, dodecyl-
carboxylic acid, dodecylmercaptan, octadecylphenol! octadecyl-
alcohol, octadecylcarboxylic acidl octadecylmercaptan. The
use of octadecylalcohol (stearyl alcohol) is particularly
preferred. The modified polyether polyol thickening agents of
-16-
~ ~3~
the invention are prepared by reacting an alpha~olefin epoxide
either by copolymerization with ethylene o~ide or ethylene
oxide and said lower alkylene oxides or polymerization sub-
sequent to the formation of a base polyether intermediate,
said alpha-olefin epoxide having about 12 to about 18 carbon
atoms. The polyether polyol thickening agent of the invention
can be an alpha-olefin epoxide capped heteric or block co-
polymer of ethylene oxide and at least one lower alkylene
oxide having 3 to 4 carbon atoms; an alpha-olefin epoxide
capped ethylene oxide homopolymer; or a heteric copolymer of
ethylene oxide, said lower alkylene oxide, and said alpha-
olefin epoxide. Said ethylene oxide is used in the proportion
of at least 10 percent by weight based upon the total weight
of the polyether. Preferably, about 70 to 99 percent by
weight ethylene oxide is utilized with about 30 to 1 percent
by weiyht of lower alkylene oxide having 3 to 4 carbon atoms.
The preparation of polyether polyols is well known
in the art~ Polyether polyols are generally prepared utilizing
an active hydrogen-containing compound in the presence of an
acidic or basic oxyalkylation catalyst and an inert-organic
solvent at elevated temperatures in the range of about 50C to
150C under an inert gas pressure generally from about 20 to
about 100 pounds per square inch gauge. Modification of these
polyether polyols can be accomplished by further reacting
the polyether polyol having a molecular weight of about 1000
to about 25,000 with said alpha-olefin epoxide so as to
provide an alpha-olefin epoxide cap on the base polyether
polyol~ The amount of alpha-olefin epoxide required to obtain
,.'
3~
the modified polyether polyol thic]cening agents of the inven-
tion is about 7 to about 20 percent by weight based upon the
total weight of the modified base polyether polyol thickeners.
Alternatively, the modified polyether polyol
thickening agents can be obtained by copolymerizing a mixture
of ethylene oxide, at least one other lower alkylene oxide
having 3 to 4 carbon atoms, and an alpha-olefin epoxide having
about 12 to about 18 carbon atoms, or mixtures thereof.
Further details of the preparation of the alpha-olefin epoxide
modified polyether polyol thickening agents useful in the
preparation of the hydraulic fluids and metalworking fluids of
the invention can be obtained in co-pending Canadian.Patent
application S rial Nos~ 362901, 362902, both filed on October
21, 1980.
Generally, at least 50 percent by weight, preferably
about 40 to 60 percent by weight of the modified polyether
polyol is used together with about 60 to about 40 percent by
weight of an unthickened hydraulic fluid or metalworking fluid
concentrate.
The metal deactivators and corrosion inhibitors
which can be added either to the concentrate or to the hy-
draulic fluid or metalworking compositions of the invention
are as follows:
Liquid-Vapor Phase Corrosion Inhibitors
The liquid-vapor corrosion inhibitor can be any o~
the alkali metal nitrites, nitrates, phosphates, silicates,
-18-
~ .~ 63~'1 1
and benzoates. Certain amines are also useful. The inhi
bitors can be used individually or in combinations. Represen-
tative examples of the preferred alkali metal nitrates and
benzoates which are useful are as follows: sodium nitrate,
potassium nitrate, calcium nitrate, barium nitrate, lithium
nitrate, strontium nitrate, sodium 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, dimethylethanolamine,
alpha- and gamma- picoline, and piperazine. A particularly
preferred vapor phase corrosion inhibiting compound is morpho-
line. As corrosion inhibitors, a proportion of from about
0.05 percent to about 2 percent by weight is used based upon
the total weight of the hydraulic fluid or metalworking
composition of the invention. Preferably, about 0.5 percent
to about 2 percent by weight of these amines are used.
Metal Deactivators (Chelating Agents)
The metal deactivators 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 deriva-
tives of salicylidenes. Representative specific examples of
these metal deactivators are as follows: benzotriazole,
tolytriazole, 2-mercaptobenzothiazole, sodium 2-mercapto-
benzothiazole, and N,N'-disalicylidene-1,2-propanediamine.
_l g_
41 1
I~ is also contemplated to add other known corrosion
inhibitors. Besides the amines, alkali metal nitrates,
benzoates and nitrates listed above, the alkoxylated fatty
acids are useful as corrosion inhibitors.
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 emulsification prior
to use, for instance, with anionic or nonionic surfactants.
Useful representative anionic or nonionic surfactants are:
sodium petroleum sulfonate, i.e., sodium dodecylbenzene
sulfonate; polyoxyethylated fatty alcohol or fatty acid and
polyoxyethylated alkyl phenol.
A typical recipe for the emulsification of the
sulfurized molybdenum or antimony compound of the invention
(sulfurized oxymolybdenum or oxyantimony organo-phosphorodi-
20 thioates) is as follows:
Emulsifier ~ by Weight
Sodium dodecylbenzene sulfonate 70
Ethylene glycol monobutyl ether 23
Butyl alcohol 7
100
-20-
`~ ~ 63V~ 1
% by Weight
Emulsifiable concentrate (hereafter termed emulsion~
Sulfurized molybdenum or
antimony compound 40
Emulsifier 60
100
A typical high water-base hydraulic fluid or
metalworking additive of the invention will contain the
components shown in Table II.
Table II
Typical Composition of Hydraulic
Fluid or Metalworking Additive
Component Parts by Weight
water (distilled or deionized) 2.5-32.5
Polymeric thickener 80-5Q
Water-soluble ethoxylated ester 3-10
Molybdenum or antimony compound
at 40% solids emulsion 1 5
Water-soluble alkyl phosphate ester0. 1-1. O
Me~al deactivator 0.1~0.5
Corrosion inhibitor 0.5-1.0
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 100F, which
are stable over long periods of storage at ambient temperature.
In addition, the hydraulic fluids and metalworking 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
-21-
`~ 3 ~304 1
fluids and metalworking additives of the invention are ecologi-
cally clean and nonpolluting 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
petroleum, the production of such fluids is relatively inde-
pendent 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 200-2000 pounds per square inch since they have all
the essential properties required such as lubricity, viscosity
and corrosion protection. The hydraulic fluids of the inven-
tion are suitable for use in various types of hydraulic
systems and are especially useful in systems in which vane-
type pumps or the axial-piston pumps are used. Such pumps are
used in hydraulic systems where pressure is required for
molding, clamping, pressing metals, 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 invention,
a test generally referred to as the Vickers Van Pump Test is
employed. The apparatus used in this test is a hydraulic
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
-22-
~ 3 ~3~
to, a 25 horsepower, 1740 rpm electric motor. The fluid i6
discharged from the pump through a pressure regulating valve.
From there it passes through a calibrated venturi (used to
measure flow rate) and back to the sump. Cooling of the fluid
is accomplished by a heat exchanger through which cold water
is circulated. No external 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 cartridge". The "pump cartridge" assembly
consists of fr~nt 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 con-
nected to a shaft which is turned by an electric motor. A
plurality of removable 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 bushings.
The inner surface of the cam-ring is cam-shaped. Turning the
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 test fluid and running at temperatures ranging from 100 to
-23-
~ ~ ~30~ 1
135F at 750 to 1000 psi 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 dissasembly for weighing, visual
examination of the system was made for signs of deposits,
varnish, corrosion, etc.
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, proportions, and percentages
are by weight and all temperatures are in degrees centigrade
unless otherwise noted.
-24-
`3 ~ ~3~ 1
_amples 1 - 3
Elydraulic fluid concentrates were prepared having
the compositions in percent by weight of:
Ingredient Example 1 Example 2 Example 3
Polyoxyethylene 20
sorbitan monostearate 23.53 36.36 38.00
Sulfurized oxymolybdenum
organophosphordithioate 17.65 27.27 31.00
Alkylphosphate ester5.88 9.10 8.00
Morpholille 29.41 15.15 15.00
Sodium-2-mercaptoben~o-
thiazole 23.53 12.12 8.00
The fluids were clear, dark amber in color, free
flowing and showed no phase separation upon aging at room
temperature. Upon diluting the concentrates with tap water to
obtain hydraulic fluids containing 1, 3 and 5 percent of each
of the concentrates, homogeneous mixtures were obtained.
The alkyl phosphate ester utilized in these examples
was obtained by the reaction of two moles of phosphorus
pentoxide with the surface-active agent condensation product
obtained by reacting one mole of oleyl alcohol and 4 moles of
ethylene oxide.
Example 4
In this example, a heteric copolymer of ethylene
oxide and 1,2-propylene oxide is prepared having a molecular
weight of about 8717. Subsequently, this base heteric co-
polymer is further reacted with a mixture of alpha-olefin
epoxides having 15 to 18 carbon atoms sold under the trademark
VIKOLOX 15-18 by the Viking Chemical Company.
-25-
~ ~ ~30~. ~
Into a stainless steel one-gallon autoclave, there
was charged 972 grams of stearyl alcohol, 89.6 grams of a 45
percent aqueous solution of potassium hydroxide and the
mixture was heated with stirring at 115C at a pressure of
less than 10 millimeters of mercury for 30 minutes. The
vacuum was relieved with dry nitrogen to a pressure of 5
pounds per square inch gauge, and a mixture of 407 grams of
propylene oxide and 1~20 grams of ethylene oxide were added
over a period of 4 and 3/4 hours at a temperature of 115C.
After addition was complete, the mixture was stirred 70
minutes at 115C and cooled to 80C. The product labeled
intermediate No. 1 was thereafter discharged to a one gallon
glass bottle for use in the next step.
Using the previously prepared intermediate, 476
grams of said intermediate were charged to a one-gallon
stainless steel autoclave which had been previously flushed
with nitrogen and heated for 15 minutes at a temperature of
115C and a pressure of 10 millimeters of mercury. After
relie~ing the vacuum to a pressure of 5 pounds per square inch
gauge with nitrogen, a mixture of 1303 grams of propylene
oxide and 3909 grams of ethylene oxide were added over a
period of 14 hours at a temperature of 115C. After the
addition of these ingredients was complete, the mixture was
stirred for a period of two hours at a temperature of 115C
and then cooled to 80C. The second intermediate product was
discharged to a one-gallon bottle in a yield of 55~9 grams of
liquid intermediate.
-26-
3 ~ B304 1
Utilizing a 2600 grams portion of the above second
intermediate product, a five-liter glass vessel was charged
and thereafter the vessel and its contents were heated at a
temperature of 120C under a nitrogen atmosphere at a pressure
of 20 millimeters of mercury for a period of 30 minutes.
Thereafter, 76 grams of a mixture of alpha-olefin epoxides
having 15 to 18 carbon atom chains and sold under the trade-
mark VIKOLOX 15-18 by the Viking Chemical Company was added
all at once. After heating this mixture for a period of 8
hours at a temperature of 120~C under a nitrogen atmosphere at
atmospheric pressure, the product was cooled to 80C and
discharged to a glass container. The product was character-
ized as a viscous brown liquid at room temperature.
Tables III-V respectively show the viscosity of the
concentrate of Example 3 when diluted with tap water to make a
hydraulic fluid, the viscosity of the alpha-olefin epoxide
modified polyether polyol thickener of Example 4 upon dilution
with water, and the use of five percent by weight of the
concentrate of Example 3 in combination with two and one-half
to five percent of the alpha-olefin epoxide modified polyether
polyol of Example 4. The surprising increase in viscosity
shown in Table V for the combination of thickener and hy-
draulic fluid concentrate is unexpected and advantageous in
that lesser amounts of thickener would be required than
expected to produce a thickened hydraulic fluid or metal-
working lubricant thus resulting in a cost saving.
3 ~ 4 1
Table III
Viscosity of Hydraulic Fluid
rom Concentrate of Example 3 in Water
Concentration in Water Viscosity (SUS)
(% by weight) at 100~F
1.0 34
3.0 54
5.0 56
Table IV
Viscosity of Thickener of
Example 4 in Water
Concentration in Water Viscosity (SUS)
(% by weight) at 100 F
2.5 32
5.0 42
.0 77
Table V
Viscosity of Mixtures of the Concentrate of
Example 3 & the Thickener of Example 4 in Water
Concentration in Water Viscosity (SUS)
(% by weight) at 100F
Example 3 Example 4
5.0 2.5 50
5.0 3.0 87
5.0 3.5 216
5.0 4.0 373
5.0 5.0 1299
Example 5
Usin~ 3.5 percent by weight of the thickener of
Example 4 and 5 percent by weight of the hydraulic fluid
-28-
~ ~ 630~ ~1
concentrate of Example 3 with the remainder of the composition
tap water, a water-based hydraulic fluid having a viscosity of
216 SUS was prepared and tested for stability under conditions
of high shear in a Vickers V-104C hydraulic vane pump. The
hydraulic fluid was tested at 1000 pounds per square inch
pressure at a temperature of 100F for a period of 89 hours.
Samples of the hydraulic fluid were taken at various time
intervals during the test and the viscosity determined. Tne
reduction in viscosity is indicative of the relative degree of
shear stability of the hydraulic fluid.
Table VI
Vickers Vane Pump Test -~ Shear Stability
of Hvdraulic Fluid of Example 5
,
Test Time Viscosity Viscosity
(hours~ (SUS) at 100F ~ loss
0 216 ---
3 213 1.4
8 209 3.2
~06 4.6
24 196 9.3
195 g.7
89 194 10.~
As shown in Table VI, the overall change in vis-
cosity of the fluid after 89 hours running time is about 10
percent which indicates good shear stability performance in
the Vickers Vane Pump.
-29-
~ 1 ~3~
The hydraulic fluid of Example 5 was also tested for
wear performance in a hydraulic vane pump. The test was
conducted in the Vickers V-104C vane pump at 1000 pounds per
square inch pressure, at a temperature of 100F, for a period
of 89 hours. Ring and wear losses were determined at various
time intervals and the results are shown in Table VII.
Table VII
Vickers Vane Pump Test - Wear Performance
of Hydraulic Fluid of Example 5
Wear-loss in Weight (total)
Test Time Ring and Vanes
(hours) (grams)
0.66
1.19
89 1.76
The weight loss of the ring and vanes shown in Table
VII is indicative of acceptable lubricity performance in the
vane pump.
While this invention has been described with
reference to certain embodiments, it will be recognized by
those skilled in the art that many variations are possible
without departing from the scope and spirit of the invention
and it will be understood that it is intended to cover all
changes and modifications of the invention disclosed herein
for the purposes of illustration which do not constitute
departures from the spirit and scope of the invention.
-30-
`~ 3 630~ ~L
SUPPLEMENTARY DISCLOSURE
The principal disclosure (-the entire contents of which
are herein incorporated by reEerence) relates to -thickened
high-viscosity, water-based hydraulic fluids and metal-working
fluids. Said fluids comprise a water-soluble polyoxyethyla-ted
aliphatic ester, a sulfurized metallic compound, a phosphate
ester salt, and a polyether polyol thickening agent. Optionally,
the fluids can include a corrosion inhibitor and a metal deac-
tivator. The use of a polyether polyol (polyether) thickening
agent having a molecular weight of about 1000 to about 25,000
preferably about 1000 to about 10,000, derived from the reac-
tion of ethylene oxide or ethylene oxide and at least one lower
alkylene oxide having 3 -to 4 carbon atoms with an active hydrogen-
containing initlator having no more than one active hydrogen
and further modified by reaction with an alpha-olefin epoxide
(oxide) having about 12 to about 18 carbon atoms, unexpectedly
provides a surprising increase in viscosity.
Alternatively, the modified polyether polyol thickening
agents can be ob-tained by copolymerizing a mixture of ethylene
oxide, at least one other lower alkylene oxide having 3 to 4
carbon atoms, and an alpha-olefin epoxide having about 12 to
about 18 carbon atoms, or mixtures thereof.
Alternatively to the use of the above-described alpha-
olefin oxides, it is possible in accordance with the present
invention , to substitute glycidyl ethers which can be
prepared by reaction of an alcohol having 12 to about 18 carbon
atoms with epichlorohydrin in accordance for example with the
teachings of U.S. 4,086 " 79 and the references referred to
thel'ein.
Thus, the present invention, in particular provides
a hydraulic fluid or metalworking fluid concen-tra-te capab].e of
. . 0.
.
- 31 -
i ~ ~3~
imparting to water the properties of a lubricant such as resis~
tance to extreme pressure and corrosion inhibition, said con-
centrate consisting essentially of :
A. a water-soluble polyoxyethylated aliphatic
ester consisting of esters of ethyoxylated
aliphatic mohonydric and polyhydric alcohols
or ethoxylated aliphatic acids wherein said acids
or alcohols have about 5 to about 20 moles
of ethylene oxide aclded per mole of acid or
alcohol and wherein said alcohols and acids
: have carbon chain lengths of 8 to 36 carbon
atoms and wherein said esters are produced
by first polyoxyethylating a-t least one-of
said acids or alcohols, and , second, obtaining
the ester reaction product therPof,
B. a sulfurized metallic compound of the formula:
¦ \
\ ~ S M2S2 2
O 2
R _
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 iD the alkyl group
and wherein the rat1o of said water-soluble ester
; to said sulfurized metallic compound is Erom 5:1
to 2:1 by weight based upon the weight of the sulfur
in said metallic compoundj
C~ a phosphate ester salt selected from the group
consisting of
- 32 -
3 ~ 4 1
o o
Il 11
RO - (EO)n- P -OX and RO (EO)n -p (EO)n OR
OX OX
and mixtures thereof , wherein EO is e-thylene
oxide, R is selected from the group consisting
of linear or branched chain alkyl groups having
about 6 to 30 carbon atorns or alkylaryl groups
wherein said 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, n is a number from l to
: 50 and wherein the proportion of said phosphate
; ester to said sulfurized metallic compound i5
about 0.1:1 to about 2:1 based upon the weight
of the sulfur in said metallic compound,
- D. a polyether thickener having a molecular weight
of about 1000 to about 25,000, prepared by react-
ing ethylene oxide or ethylene oxide and at least
one lower alkylene oxide having 3 to 4 carbon
atoms with at least one active hydrogen-contain-
ing aliphatic or alkylaromatic initiator contain-
ing no more than one active hydrogen and at
least one glycidyl ether having a carbon chain
length of about 12 to about 18 aliphatic carbon
atoms and wherein said glycidyl ether is present
in the amount of about l to about 20 percent by
weight based upon the total weight of said thickener,
and optionally
E. a corrosion inhibitor and a metal deactivator.
- 33 -
~ : .
~ ~ ~30'1 1
In accordance with this invention, the polyether thickener
may be prepared by copolymerizing a mixture of ethylene oxi.de
and at least one of said lower al]cylene oxides in the presence
of said initiator selected from -the group consisting of alkane
monoalcohols, alkene monoalcohols , and alkyne monoalcohols
to produce a liquid heteric copolymer intermediate and subse-
quently reacting said intermediate with at least one of said
~lycidyl ether.
In accordance with the present invention, the polyether
thickener may be prepared by sequentially reacting ethylene
oxide with at least one of said lower alkylene oxides to produce
a block copolymer intermediate and subsequently reacting said
intermediate with at least one of said glycidyl ether.
In accordance with the present invention, the glycidyl
ether may be in a mole ratio to said initiator of about 1:5
to about 1:15.
In accordance wi-th the invention, the lower alkylene oxides
may be selected from the group consisting of 1,2-propylene oxide,
1,2-butylene oxide, 1,3-butylene oxide, 1,4-butylene oxide,
2,3-butylene oxide and tetrahydrofuran and the proportion of
ethylene oxide residue in said thickener mav be at least 10
percent by weight of the total weight of said thickener.
' In accordance with,the invention, the proportion of
ethylene oxide residue to the residue of the lower alkylene
oxides may be from 70 to about 99 percent by weight of ethylene
oxide residue to about 30 to about 1 percent by weight of the
s,aid lower alkylene oxide residue and said active hydrogen-
containing compound may be a monohydric aliphatic alcohol,.
In accordance with the invention, the initiator may
30 ' ,be selected from the group consisting of at least one of
stearyl alcohol , lauryl alcohol and myristyl alcohol.
The glycidyl e-ther may be in a mole ra-tio to said initia-tor
~ 3~ -
~ ~ ~30~ ~
of about 1:5 to about 1:15.
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 an-tiwear charac-
teristics or asmetalworking compositions used to cool and
lubricate surfaces which are in frictional contac-t such as
during the operat.ions of turning, cutting, peeling, grinding
metals and the like. The hydraulic fluids and metalworking
compositions oE the invention are ecologically superior to
those fluids and metalworking emulsions of the prior art con-
taining mineral oil or a glycol/water mixture.
'
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