U.S. patent number 3,676,344 [Application Number 05/069,071] was granted by the patent office on 1972-07-11 for ether amides in aqueous lubricants.
This patent grant is currently assigned to The C. P. Hall Company of Illinois. Invention is credited to Vincent P. Kuceski.
United States Patent |
3,676,344 |
Kuceski |
July 11, 1972 |
**Please see images for:
( Certificate of Correction ) ** |
ETHER AMIDES IN AQUEOUS LUBRICANTS
Abstract
Metals, when rolled or otherwise compressed, are lubricated by
an aqueous solution of an organic, polar, surface-acting
composition having a negative heat of solution which is an ether
amide which is soluble in the water at a lower temperature but
insoluble in the water at the temperature to which the aqueous
solution is heated during compression of the metal. This aqueous
lubricant eliminates the fire hazard involved in the use of the
present non-aqueous lubricants.
Inventors: |
Kuceski; Vincent P. (Chicago
Heights, IL) |
Assignee: |
The C. P. Hall Company of
Illinois (Chicago, IL)
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Family
ID: |
22086550 |
Appl.
No.: |
05/069,071 |
Filed: |
September 2, 1970 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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791259 |
Jan 15, 1969 |
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Current U.S.
Class: |
508/555 |
Current CPC
Class: |
C10M
173/02 (20130101); C10M 2215/08 (20130101); C10N
2050/01 (20200501); C10N 2040/245 (20200501); C10M
2201/02 (20130101); C10M 2215/042 (20130101); C10M
2215/28 (20130101); C10N 2040/243 (20200501); C10N
2040/244 (20200501); C10N 2040/247 (20200501); C10N
2040/241 (20200501); C10M 2215/082 (20130101); C10N
2040/246 (20200501); C10N 2040/24 (20130101); C10N
2040/242 (20200501) |
Current International
Class: |
C10M
173/02 (20060101); C10m 001/36 () |
Field of
Search: |
;252/49.3,49.5,51.5A |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wyman; Daniel E.
Assistant Examiner: Cannon; W.
Parent Case Text
This application is a continuation-in-part of my application Ser.
No. 791,259 filed Jan. 15, 1969 now abandoned.
Claims
I claim:
1. The method of rolling or extruding metals which comprises
rolling or extruding a metal while its surface is lubricated with
mineral-oil-free aqueous solution of 1 to 20 per cent of an ether
amide which is soluble in the water at the temperature and
concentration at which it is supplied for use in the method and has
the formula ##SPC4##
in which R is an alkyl, cycloalkyl, aryl, aralkyl or alkaryl group
of six to 24 carbon atoms; m is 0, 1 or 2; and n equals the number
of recurring alkyl ether groups and may be any number from 2 to
100, inclusive, and from which the lubricant is separated as the
solution is heated by heat generated by the compression of the
metal, and thereby separating lubricant from the solution and
depositing it on the surface of the metal being tested.
2. The method of claim 1 in which the ether amide has the
formula
3. The method of claim 1 in which the ether amide has the
formula
4. The method of claim 1 in which the metal article is a metal
sheet. 5. The method of claim 1 in which metal is lubricated as it
is rolled, and the separation temperature of the aqueous lubricant
is between substantially 30.degree. and 95.degree. C.
Description
This invention relates to the use of an aqueous lubricant on
metals, including aluminum and magnesium, etc. during size
reduction, as in rolling, extrusion or other compression. The
aqueous lubricant is to replace the oil-based lubricants presently
employed, and because of the large amount of water present the
aqueous lubricant is preferred because it eliminates the fire
hazard which is present when highly heated metal and an oil are
brought into contact with one another. By eliminating the fire
hazard, size reduction operations can be carried out at faster
speeds at which the metal is heated to a higher temperature at
which the danger of fire would be increased if an oil lubricant
were used.
The solute of the aqueous lubricant used in carrying out the
invention is a material which has a negative heat of solution and
is more soluble in water at a lower temperature at which it is
supplied to the rolling or extrusion system, and is less soluble at
a higher temperature to which it is heated during the rolling or
extrusion so that it separates from solution as a solid or liquid
and serves as a lubricant.
The lubricant is an organic, polar, surface-acting composition--an
ether amide--which has a negative heat of solution and is soluble
in water at a lower temperature and separates at the higher
temperature to which it is heated during the operation. It is free
from mineral oil.
The ether amides which are useful in carrying out this invention
have the following representative formulas: ##SPC1##
In which R is an alkyl, cycloalkyl, aryl, aralkyl or alkaryl group
of six to 24 carbon atoms; m is 0, 1 or 2; and n equals the number
of recurring alkyl ether groups and may be any number from 2 to
100, inclusive. The amide group contributes water solubility
equivalent to about three or four ether groups. In other words, if
R+m/n+3 = about 0.5 to 2.5, or preferably 0.8 to 2.0, a good
lubricant is obtained with a concentration of about 5 to 10 or 20
per cent of the amide in water. Compounds of the first formula are
listed in Table I and compounds of the second formula are listed in
Table II. These compounds are listed as representative of those
which can be used satisfactorily. ##SPC2## ##SPC3##
The concentrations of the chemical compounds having negative
solubility, as they are used in aqueous solutions may vary from a
few tenths of one per cent up to 25 or 50 per cent or more, and is
usually 1 to 20 per cent, depending upon the nature of the compound
and the temperatures to which the aqueous solution is subjected in
the treatment of different metals. In most instances, the amount
dissolved in the aqueous phase will depend on the viscosity and
lubricity obtained. Generally, a clear solution which is easily
pumped is required so that the solution may be filtered to remove
suspended particles. Such filtration is generally essential for the
production of a metal product with a bright unmarred finish.
The temperatures of solution and separation of the lubricant will
vary, depending upon the metal being treated and the method of
treatment. Usually the lubricant should be soluble at about room
temperature. The temperature of rolling will depend upon the metal,
etc. In rolling, the aqueous lubricant may be sprayed on upper and
lower rolls, or the lower roll may be immersed in a bath of the
lubricant. In extrusion the lubricant is added in any desired
manner.
The invention is further described in connection with the
accompanying drawings which are largely schematic.
FIG. 1 is a vertical section through equipment for a rolling
operation; and
FIG. 2 is a vertical section through equipment used in
extrusion.
FIG. 1 is illustrative of the application of the invention to one
method of rolling a metal; namely, the cold-rolling of aluminum. It
will be noted that the thickness of the metal 1 is reduced to that
shown at 2 as the metal is passed between the rolls 4 and 5.
The tank 7 contains a clear, aqueous solution of lubricant which is
continuously or periodically drawn off through the pipe 10 and
filtered and returned through the pipe 11, usually some going to
the spray head 13 and the balance being returned through the pipe
14 to the tank. If the filtering operation is carried out only
periodically at long intervals, some of the clear lubricant from
the tank 7 can be pumped directly to the spray 13 through pipe 14
for spraying the upper roll 4 while the lower roll 5 is rotated
while partially submerged in the lubricant contained in the tank.
As the aluminum or other metal is reduced from the thickness 1 to
the thickness 2, a great deal of heat is given off and the rolls 4
and 5 become heated. The temperature of the bath may be controlled
manually or automatically within a few degrees below the
precipitation temperature to prevent overheating which would
precipitate the lubricant. Water or lubricant may be added as
required to maintain the desired concentration.
In starting up the operation the liquid sprayed on to the roller 4
and the entire liquid within the tank is clear. As the rolls 4 and
5 heat up, these rolls become hot enough to cause separation of the
lubricant from the water solution either as a separate liquid phase
or in particular form. The drawing illustrates how, after the rolls
4 and 5 have been heated up, the liquid is converted to particulate
form on the roll 4 due to its heat, and the heat of the roll 5
tends to cause separation of the solute adjacent the roll 5 as it
is rotated in it. Thus the lubricant is supplied as a clear aqueous
solution at a lower temperature and as heat is generated by the
rolling operation and the rolls 4 and 5 become more and more heated
the lubricant separates more rapidly after contact with the heated
roll 4, and the lubricant surrounding the roll 5 separates and the
separated phase adheres to the roll as it continues to rotate and
carry the separated lubricant to the interface between the roll and
the metal being treated. It is here that the lubricant which
separates at a higher temperature performs its useful function. For
example, in rolling aluminum, the separation may start at any
temperature between 30.degree. and 95.degree. C.
The solute which separates on the roll 4 as the spray becomes
heated and the solute which separates on the roll 5 as it becomes
heated adhere to the rolls and are carried to the interface where
they serve to lubricate the surface between the roll and the metal,
thereby forming a smooth surface on the metal as well as cooling it
while it is being compressed. The advantages of this method of
producing a lubricant are not immediately apparent.
Heretofore, lubricants used in extruding or rolling metals when
used with water, have been in a necessarily very stable finely
divided or nearly colloidal emulsion form. The manufacture of a
finely divided emulsion has been difficult and it has also been
difficult to maintain the emulsion over different conditions of
operating temperatures and speeds. In order to be a good lubricant,
the lubricant must be brought out and made available to the metal
surface. The better lubricants were made as emulsions which were
deliberately made unstable so that the lubricant would separate out
as a distinct phase. However, such unstable emulsions are difficult
to handle and frequently are so heterogeneous that they do not give
a uniform coating of lubricant at all times.
This invention overcomes the above difficulties by providing a
homogeneous solution containing a controlled amount of lubricant
which lubricant is freed at the point and at the time most needed
for lubricity. Upon cooling, the lubricant re-enters solution and
maintains a uniform concentration of the bath. As the lubricant is
separated from the aqueous phase by the increase in temperature,
some, or nearly all, of the water is evaporated, which further
concentrates the lubricant. This evaporation of the water leaves
behind a uniform film of lubricant on the rolls 4 and 5 which is
transferred to the metal. Although evaporation also occurs in the
usual emulsion system, the remaining lubricant film is spotty and,
therefore, does not yield a smooth and continuous deposit on the
roll or on the metal as does the lubricant of this invention.
In the practice of this invention the cold-rolling system, when it
is first started, will not contain heat in the rolls 4 or 5, or in
the metal 2. Therefore, the rolls should be heated up by some
means, either electrically or by steam, in
The solutes which may be used in preparing the lubricant solutions
may be compounds well known in the literature, or they may be new
compounds which have properties desired in the aqueous lubricant. A
mixture of compounds having different properties may be employed to
give the desired solubility and lubricity at required
temperatures.
The following are examples of the amide ethers which may be used in
carrying out this invention. In the table, only two examples are
shown to illustrate the effect of the ethylene oxide groups on the
amide-type of derivative. The tallow amide is saturated and is
somewhat less soluble than the unsaturated amide and separates at a
lower temperature. The tests were made on heating a 1% aqueous
solution of the amide ether:
Moles Ethylene Separation Point Amide Oxide .degree.C.
__________________________________________________________________________
Red oil 5 90 Hydrogenated 5 85 tallow amide
__________________________________________________________________________
In rolling a metal such as aluminum, for example, the ingot is
usually passed through one set of rolls in one direction and then,
after narrowing the bite of the rolls, it is passed between the
same rolls in the opposite direction, and this is repeated to
gradually reduce the thickness of the sheet-usually without much
widening of the sheet. Eventually it is often transferred to other
rolls for the final rolling operation or operations. As the
thinning process proceeds the temperature of the sheet increases.
In operations where an oil lubricant has been employed the speed of
the operation has to be reduced to prevent the metal from becoming
so hot as to ignite the oil. An advantage of the use of an aqueous
lubricant is that the danger of ignition is eliminated and the
speed of the operation can be increased because the water is a
better coolant and the evaporation of water operates to keep the
rolls and the treating bath cool. If the speed of the operation is
too fast using the conventional non-aqueous lubricants, eventually
the bath temperature becomes very high and there is an economic
loss of volatile hydrocarbon and ester-type of lubricant medium.
The rolls also become too hot, and the rolled sheet is neither as
smooth nor bright as desired. The advantage of using the aqueous
system is that the speed of the rolling operation can be increased
four or five fold because the heat is easily carried off or
controlled both by the evaporation of the water and by the high
heat capacity of water. The amount of water evaporated may be
considerable, but this is infinitesimally small in comparison to
the losses that would be effective if an equal quantity of
non-aqueous lubricant were evaporated.
In the practice of this invention, from 1 to 20 per cent or more of
the compound, and preferably 5 to 10 per cent, having a negative
heat of solution is dissolved in water to form a clear, homogeneous
solution.
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