Note: Descriptions are shown in the official language in which they were submitted.
~053~54
This invention relates to metal working operations
and more particularly to a lubricant for use during such
operat~ons. Still more particularly, it relates to a method
for lubricating metal during working thereof which comprises
applying to said metal a composition comprising (A) an oil
of lubricating viscosity, (B) a carboxylic acid or derivative
thereof, and (C) a phosphorus acid salt having the formula
R (X )a ¦¦ 4
R (X )b /
wherein M is a Group I metal, a Group II metal, aluminum,
tin, cobalt, lead, molybdenum, manganese, nickel or ammon-
ium; each of R and R2 is a hydrocarbon-based radical;
each of X , X , X and X is oxygen or sulfur; and each of
a and b is 0 or 1.
Metal working operations, for example, rolling,
forging, hot-pressing, blankingJ bending, stamping, drawing,
cutting, punching, spinning and the like generally employ
a lubricant to facilitate the same. Lubricants greatly
improve these operations in that they can reduce the power
; required for the operation, prevent sticking and decrease
wear of dies, cutting bits and the like. In addition, they
frequently provide rust inhibiting properties to the metal
being treated.
Since it is conventional to sub~ect the metal to
various chemical treatments (such as the application of
conversion coating solutions) after working, a cleaning
operation is necessary between the working step and the
chemical treatment step. In addition to the above proper-
ties, therefore, it is preferred that the working lubricant
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be easily removable from the metal surface by ordinary
cleaning compositionsO
A principal object of the present invention,
therefore, is to provide an improved metal working method.
A further object is to provide a method using
lubricants which provide to the metal being worked a unique
combination of properties including lubricity, corrosion
resistance, extreme pressure properties and protection
against wear of working parts, and which in addition are
relatively easy to remove from the surface of the metal by
cleaning after the working operation is completedO
Other ob~ects will in part be obvious and will in
part appear hereinafterO
The metal working compositions used in the method
of this invention contain three essential components. Com-
ponent A is an oll of lubricating viscosity. (As used herein,
the singular forms "a", "an" and "the" include the plural
unless the context dictates otherwise. Thus, for example,
"an oil of lubricating viscosity" includes a mixture of such
oils.) Both natural and synthetic oils are suitable.
Natural oils include animal oils and vegetable oils (e.g.,
castor oil, lard oil) as well as liquid petroleum oils and
solvent-treated or acid-treated mineral lubricating oils
of the paraffinic, naphthenic or mixed paraffinic-naphthenic
types. Oils of lubricating viscosity derived from coal or
shale are also useful. Synthetic lubricating oils include
hydrocarbon oils and halosubstituted hydrocarbon oils such
as polymerized and interpolymerized olefins (e.g., poly-
butylenes, polypropylenes, propylene-isobutylene copolymers,
~0 chlorinated polybutylenes, etc.); poly(l-hexenes), poly(l-
octenes), poly(l-decenes), etc and mixtures thereof;
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alkylbenzenes (e.g., dodecylbenzenes, tetradecylbenzenes,
dinonylbenzenes, di-(2-ethylhexyl)-benzenes, etc.); poly-
phenyls (e g., biphenyls, terphenyls, alkylated polyphenyls,
etc.), alkylated diphenyl ethers and alkylated diphenyl
sulfides and the derivatives, analogs and homologs thereof
and the like.
- Alkylene oxide polymers and interpolymers and
derivatives thereof where the terminal hydroxyl groups have
been modified by esterification, etherification, etc. con-
stitute another class of known synthetic oils. These are
exemplified by the oils prepared through polymerization of
- ethylene oxide or propylene oxide, the alkyl and aryl
ethers of these polyoxyalkylene polymers (e.g., methyl-
polyisopropylene glycol ether having an average molecular
weight of 1000, diphenyl ether of polyethylene glycol
having a molecular weight of 500 - 1000, diethyl ether of
polypropylene glycol having a molecular weight of 1000 -
1500, etc.) or mono- and polycarboxylic esters thereof,
for example, the acetic acid esters, mixed C3-C8 fatty acid
esters, or the C~ Oxo acid diester of tetraethylene glycol.
Another suitable class of synthetic oils com-
prises the esters of dicarboxylic acids (e.g., phthalic
acid, succinic acid, alkyl succinic acids and alkenyl
succinic acids, maleic acid, azelaic acid, suberic acid,
sebacic acid, fumaric acid, adipic acid, linoleic acid
dimer, malonic acid, alkyl malonic acids, alkenyl malonic
acids, etc.) with a variety of alcohols (e.g., butyl
alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl
alcohol, ethylene glycol, diethylene glycol monoether,
~0 propylene glycol, etc.). Specific examples of these esters
~3--
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include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-
hexyl fumarate, dioctyl sebacate, diisooctyl azelate,
diisodecyl azelate, dioctyl phthalate, didecyl phthalate,
dieicosyl sebacate, the 2-ethylhexyl diester of linoleic
acid dimer, the complex ester formed by reacting one mole
of sebacic acid with two moles of tetraethylene glycol
and two moles of 2-ethylhexanoic acid, and the likeO
Esters useful as synthetic oils also include
those made from C5 to C12 monocarboxylic acids and polyols
and polyol ethers such as neopentyl glycol, trimethylol-
propane, pentaerythritol, dipentaerythritol, tripentaeryth-
ritol, etc.
Silicon-based olls such as the polyalkyl-,
polyaryl-, polyalkoxy-, or polyaryloxy-siloxane oils and
silicate oils comprise another useful class of synthetic
oils (e.g., tetraethyl silicate, tetraisopropyl silicate,
tetra-(2-ethylhexyl) silicate, tetra-(4-methyl-2-ethylhexyl)
silicate, tetra-(p-tert-butylphenyl) silicate, hexyl-(4-
methyl-2-pentoxy)disiloxane, poly(methyl)siloxanes, poly-
(methylphenyl)siloxanes, etc.). ~ther synthetic oils include
liquid esters of phosphorus-containing acids (e.g., tri-
cresyl phosphate, trioctyl phosphate, diethyl ester of
decylphosphonic acid, etc.), polymeric tetrahydrofurans
and the like.
Unrefined, refined and rerefined oils (and mix-
tures of each with each other~ of the type disclosed herein-
above can be used as component A according to this invention.
Unrefined oils are those obtained directly from a natural or
synthetic source without further purification treatment.
3 For example, a shale oil obtained directly from retorting
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operations, a petroleum oil obtained directly from dis-
tillation or ester oil obtained directly from an esterifica-
tion process and used without further treatment would be an
unrefined oil~ Refined oils are similar to the unrefined
oils except they have been further treated in one or more
purification steps to improve one or more properties. Many
such purification techniques are known to those of skill in
the art such as solvent extraction, acid or base extraction,
filtration, percolation, etc. Rerefined oils are obtained
by processes similar to those used to obtain refined oils
applied to refined oils which have been already used in
service. Such refined oils are also known as reclaimed or
reprocessed oils and often are additionally processed by
techniques directed to removal of spent additives and oil
breakdown products.
A particularly preferred mixture for use as
component A is a mixture of ordinary mineral oil and a
mineral oil fraction of the type generally identified as
bright stock, especially such a mixture in which the weight
ratio of bright stock to ordinary mineral oil is between
about 0.5:1 and 5.0:1. The incorporation of bright stock
in this amount frequently improves the viscosity character-
istics of the metal working lubricant.
Component B is a carboxylic acid or derivative
thereof, As used herein, the term "derivative" includes:
Anhydrides.
Esters, especially those prepared from
lower alkyl (the word "lower" meaning up to
7 carbon atoms) monohydroxy or polyhydroxy
compounds (e.g., methanol, ethanol, l-butanol,
1053654
n-hexanol, ethylene glycol, pentaerythritol)
or epoxides (eOg., ethylene oxide, propylene
oxide). The epoxide-derived compoundsJ as
will be readily understood, are hydroxy esters.
Salts (neutral, acidic or basic) in which
the cation is one of those listed hereinafter
with reference to component C, including salts
of the free acids and of their hydroxy esters.
The lithium salts are preferred for their anti-
rust properties.
Amides and amide-imide mixtures, especially
those derived from aliphatic amines and more
especially from lower aliphatic amines. The
preferred amines are the alkylene polyamines,
particularly ethylene polyamines.
Derivatives of the type described above may
be obtained from the acids by known reactions or sequences
of reactions.
The free acids, their lithium salts, and their
anhydrides are most useful as component B. Preferred are
the aliphatic carboxylic acids (and derivatives thereof
as defined hereinabove) containing at least about 8 carbon
atoms. Particularly desirable are the dibasic acids,
especially the anhydrides of succinic acids having a
hydrocarbon-based substituent, such as those prepared by
the reaction (more fully described hereinafter) of maleic
acid or maleic anhydride with a hydrocarbon-based compound
containing at least about 6 carbon atoms, pre-ferably about
6-75 and most often about 10-20 carbon atoms.
~0 As used herein, the term "hydrocarbon-based
.
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1053654
compound" denotes a compound having predominantly hydrocarbon
character within the context of this invention Such com-
pounds include the following:
(1) Hydrocarbons, whether aliphatic, (e.g.,
alkanes or alkenes), alicyclic (e.g., cycloalkanes or
cycloalkenes), aromatic, aliphatic- and alicyclic-substituted
aromatic, aromatic-substituted aliphatic and alicyclic
hydrocarbons and the like.
(2) Substituted hydrocarbons, that is, compounds
containing non-hydrocarbon substituents which, in the
context of this invention, do not alter the predominantly
hydrocarbon character of the compound~ Those skilled in
the art will be aware of suitable substituents (e.g., halide,
hydroxy, ether, keto, carboxy, ester, especially lower
carbalkoxy, amide, nitro, cyano, sulfoxy and sulfone
radicals).
(~) Hetero compounds; that is, compounds which,
while predominantly hydrocarbon in character within the
context of this invention, contain atoms other than carbon
present in a chain or ring otherwise composed of carbon
atoms. Suitable hetero atoms will be apparent to those
skilled in the art and include, for example, nitrogen,
oxygen and sulfur.
In general, no more than about three substituents
or hetero atoms, and preferably no more than one, will be
; present for each 10 carbon atoms in the hydrocarbon-based
compound.
The hydrocarbon-based compound used for the
preparation of component B should be substantially saturated,
i.e., at least about 95~ of the total number of carbon-
to-carbon covalent linkages should be saturated. It should
~053654
be free from acetylenic unsaturation and substantially free
from pendant groups containing more than about six aliphatic
carbon atoms.
The preferred hydrocarbon-based compounds used
for the preparation of component B are those derived from
substantially saturated petroleum fractions and olefin
polymers, particularly oligomers of monoolefins (especially
terminal monoolefins) having from 2 to about 10 carbon
atoms. Thus, the hydrocarbon-based compound may be derived
from a polymer of ethylene, propene, l-butene, 2-butene,
isobutene, 3-pentene, l-octene or the like. Also useful
are interpolymers of olefins such as those :illustrated
above with other polymerizable olefinic substances- such
as styrene, chloroprene, isoprene, p-methylstyrene, pipery-
lene and the like~ In general, these interpolymers should
contain at least about 80%, preferably at least about 95%,
on a weight basis of units derived from the aliphatic
monoolefins.
Other suitable hydrocarbon-Dased co~;pounds are
mixtures of saturated aliphatic hydrocarbons such as highly
refined high molecular weight white oils or synthetic alkanes.
In some instances, the hydrocarbon-based compound
should contain an activating polar radical to facilitate
its reaction with the low molecular weight acid-producing
compound. The preferred activating radicals are halogen
atoms, especially chlorine, but other suitable radicals
include sulfide, disulfide, nitro, mercaptan, ketone and
aldehyde groups.
As previously noted, the preferred method for
producing component B is by the reaction of maleic acid or
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1053654
anhydride with the hydrocarbon-based compound, especially
with a material such as a propene oligo~ler. This reaction
involves merely heating the two reactants at about 100-200C.
in the presence or absence of a substantially inert organic
liquid diluent; an excess of a liquid reactant may also
serve as the reaction medium. Other suitable reactions
for the preparation of component B include oxidation with
potassium permanganate, nitric acid or a similar oxidizing
agent of a hydrocarbon-substituted~1,4-butanediol or the
like; ozonolysis of a hydrocarbon-substituted 1,5-diene
or the like; preparation of a bis-organometallic derivative
of a hydrocarbon-substituted 1,2-dihalide or the like,
followed by carbonation thereof with carbon dioxide; or
preparation of a dinitrile followed by its hydrolysis.
All of these reactions are well known in the art, as are
the substituted succinic acids and derivatives thereof
produced thereby.
Component C is a phosphorus acid salt having the
above formula. As indicated, each of R and R therein
is a hydrocarbon-based radical. That term as used herein
denotes B radical having a carbon atom directly attached
to the remainder of the molecule and being hydrocarbon-
based as defined hereinabove with reference to component B.
Preferably, R and R are free from acetylenic and usually
also from ethylenic unsaturation and have no more than
about 30 carbon atoms, desirably no more than about 12
carbon atoms. They are usually hydrocarbon radicals such
as methyl, ethyl, propyl, butyl, amyl, hexyl, octyl, decyl,
dodecyl, vinyl, decenyl, cyclohexyl, phenyl and the like,
all isomers thereof being included. A particular preference
is expressed for compounds in which R and R are lower
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1053654
alkyl radicals, the word "lower" denoting radicals containing
up to seven carbon atoms.
It will be apparent that the compounds useful as
component C include salts of dialkylphosphoric acids or
dialkylphosphinic acids, and of thio derivatives of such
acids. Especially preferred are the salts of phosphorodi-
thioic acids; that is, compounds in which a and b are each
1, X and X are each oxygen, and X3 and X4 are each sulfur.
In these salts, M may be any of the metals previously
enumerated or ammonium; the latter term includes substituted
ammonium salts (i.e., amine salts)O M is preferably zinc
or lead, especially zinc.
The lubricant may contain other materials such as
surfactants, auxiliary anti-rust, anti-corrosion, extreme
pressure and anti-wear agents and the like; such materials
are known to those skilled in the art. A particularly
preferred auxiliary extreme pressure agent is chlorinated
wax.
The relative proportions of the ingredients in
the drawing lubricants useful in the method of this inven-
tion are not critical. Generally, it is convenient to use
about 10-40 parts by weight of component A and about
0.5-5.0 parts of component B per part of component C. When
a chlorinated wax is also present, about 0O5-3~0 parts by
weight thereof per part of component C is usually satisfac-
tory. Components B and C, and any chlorinated wax present,
usually comprise about 5-30 percent by weight of the total
composition, with the balance being component A.
It is preferred that components B and C be soluble
in component A, but the method of this invention contemplates
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the use of substantially stable dispersions comprising
components A, B and C, as well as solutions.
The constitution of typical lubricants suitable
for use in the method of this invention is given in Table I.
1053654
U~
C~i I I I
a~
I I I
a~ I I I I
o~ o~
~: C~ oo I o~ , . .
;~ ~1 ~ I ~1 1 1 1
~D
L~
a) u~ ,1
:~ c7
r~ o I I ~
C~l I I I
~q
h 1~ .
P~ 1~C~J I ,1 1 1
,
~1 ~o ~ I -
H¦ Ll~ .
~ 0~
L~
~D
C) ~ L~
CU
~ Lr~
CU O
-I ~O CU
¢
L~\ I O I I
C~
a~
I ~
:~ O ~ O
O ~ I I S~
O ~ ~ ~ rlO O
.' ~ tq~ ~ C~ ~ O
rl H,~ h O ~
~ ~ ~ ~ a) a) ~ o s~ o
X ~ ~ ,c,
O 0
~ ,1 a) o ~ ~ o a~ s~ O rl
,~ O ~ O ~_-0 ~ Lr~ ~ ,C
o c) ~1 o c~ O~o ~ C~ td O a~ c~
~C O ~ ~ h ~ C u~ h--` c~ ~ ~ O
rl ~ O ~ O
I ~ ~ ~Q.~ CQ O t~ ~ ~ O t~ C
I h~C ~ C ~ D ~ o ~ o
~ rl ~ ~ ~ ~ ~
I ~1 h ~U O rl ~1 rl
I ~ m E~
_12 -
1053654
~ l
~ ~ l l
~D
C~
U~
.
C~
~ ~ ' ~ .
H
, ~ ~ ~ .
H
m ~ l l
~3
C) ' L~ '
m
¢
I o
0 _I
X C~
~o
C~J
C~
~ o~
a) o o c~ ~
o
o ~l~
0
s~ ~5 ~ 0_,
~,
~ a~ ~
H 1~1 C)
,
-13-
~053{;54
Any metal to be worked may be treated according
to the method of this invention; examples are ferrous
metals, aluminum, copper~ magnesium, titanium, zinc and
manganese as well as alloys thereof and alloys containing
other elements such as silicon.
The compositions used in the method of this
invention can be applied to the metal workpiece prior to
or during the working operation in any suitable manner.
They may be applied to the entire surface of the metal,
or with any portion of that surface with which contact is
desired. For example, the lubricant can be brushed or
sprayed on the metal, or the metal can be immersed in a
bath of the lubricant. In high speed metal forming oper-
ations spraying or immersion are preferred.
In a typical embodiment of the method of this
invention, a ferrous metal workpiece is coated with the
lubricant prior to the working operation. For example,
if the workpiece is to be drawn it may be coated with the
lubricant before passage through the drawing die. It is
also within the scope of the invention to apply the lubri-
cant to the workpiece as it enters the die, or to apply
it to the die itself whereupon it is transferred to the
workpiece by contact. Thus, the method of this invention
in a generic sense comprises any metal working operation
wherein the workpiece has on its surface, during said
operation, the above-described lubricant regardless of how
applied.
The- lubricity properties of the compositions
used in the method of this invention are demonstrated in
~0 a test in which a cold-rolled steel strip, 2" x 1~-1/2",
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1053654
is drawn between two dies in an Instron Universal Tester,
Model TT-C. ~rior to drawing, the edges of the strip are
deburred and the strip is vapor degreased and wiped with a clean
cloth. It is then coated with the drawing lubricant and mounted
in the testing machine. The dies are tightened by means of a
torque wrench set at 40 foot-pounds torque and the strip is
pulled through the die for 2 inches at the rate of 5 inches per
minute. The force (or "load") required to pull the strip through
the die is recorded on a chart; if there is "chattering" and
irregular movement due to friction, the deviation from a uniform
load is also recorded on the chart. When a number of lubricants
are being compared, the tests are all run on the same day on
strips from the same sheet of steel.
The results of several lubricity tests are given in
Table II. The "Load" readings are those at the end of the
2-inch drawing period. All tests were run at room temperature.
The entry marked "Control 1" is a commercial chlorinated wax
drawing lubricant sold under the trade mark "T13-B"; that marked
"Control 2" is a rust inhibiting drawing oil sold under the
trade mark "Ferro Cote"; and that marked "Control 3" comprises
successive treatments with "Ferro Cote" and a fatty acid ester
drawing lubricant sold under the trade mark "Quaker 693M".
TABLE II
Test LubricantLoad, lbs. Deviation
25 1 Control 1 1125 40
C 1125 25
2 Control 2 1750 75
A 1925 0
3 Control 3 1750 0
A 1825 0
4 A 1750 0
; B 1100 0
G 1500 0
B 1350 0
C 1500 0
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The extreme pressure properties of the lubricants
are measured by means of the SAE Test, in which two Timken
cups on shafts are operated in contact with each other at
a relative speed of 500 rpm. in a bath~of test lubricant
as a load is gradually and automatically applied. The load
at which scoring occurs is the test result. When tested
by this method, the results Iisted in Table III were
obtained.
TABLE III
10Lubricant Load. lbs.
Control 1 147
B 102
C 111
The anti-wear properties of the lubricants are
evaluated by the 4-Ball Wear Test (ASTM D 2266), in which
a steel ball lubricated with the lubricant being tested is
rotated in contact with three other similar balls for one
hour at 1200 rpm., under a 40-kilogram load at room tem-
perature. The diameter of the scar on the rotated ba~l is
a measure of the amount of wear. The results in Table IV
were obtained.
TABLE IV
Lubricant Scar diameter mm.
~ A 0 48
G o:48
To eYaluate cleanability, steel panels were
coated with the drawing lubricants and were then cleaned
by means of a commercial cleaner containing potassium
hydroxide, sodium silicate and the sodium salt of ethylene-
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~053654
diaminetetraacetic acid. The cleaning is effected at 160F.
by spraying the cleaner for one minute on the metal surface
at 10 psi. The percentage of soil removed is measured,
and the degree of foaming and extent of "water breaks" are
determined by inspection. When evaluated in this wayJ
Lubricants A and B both were removed 100% from the surfaces,
with no foaming or water breaks in evidence.
Resistance to corrosion was measured by coating
panels~with the drawing lubricant and hanging them, coated
side down, about 6-8" above water in a cabinet maintained
at 1~5F. They remained in that cabinet for a predetermined
period of time, after which the percentage of rust was
determined by inspection. When evaluated in this way, a
panel coated with Lubricant A showed no rust after 66 hours
and 10% rust after 96 hours.
As indicated by the above test results, the
lubricants used in the method of this invention are com-
parable to lubricants previously available in a large
number of diverse propertiesJ all of which are important
in metal working.
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