U.S. patent number 3,720,695 [Application Number 05/154,152] was granted by the patent office on 1973-03-13 for water soluble lubricant.
This patent grant is currently assigned to Pennwalt Corporation. Invention is credited to Inara Dagnija Meisters.
United States Patent |
3,720,695 |
Meisters |
March 13, 1973 |
WATER SOLUBLE LUBRICANT
Abstract
A water soluble composition comprising the product obtained by
transesterifying a triglyceride (e.g. castor oil) with a polymeric
alkylene oxide glycol until the reaction products are water-soluble
and then esterifying the hydroxy compounds present with a
carboxylic or dicarboxylic acid. These products are of value as
lubricants in a wide variety of fields.
Inventors: |
Meisters; Inara Dagnija
(Homewood, IL) |
Assignee: |
Pennwalt Corporation
(Philadelphia, PA)
|
Family
ID: |
26851195 |
Appl.
No.: |
05/154,152 |
Filed: |
June 17, 1971 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
834556 |
Jun 18, 1969 |
3634245 |
|
|
|
Current U.S.
Class: |
554/116; 554/121;
554/122; 554/168 |
Current CPC
Class: |
C11C
3/08 (20130101); C10M 3/00 (20130101); C11C
3/04 (20130101); C10N 2040/242 (20200501); C10N
2040/24 (20130101); C10M 2207/282 (20130101); C10M
2207/283 (20130101); C10N 2040/243 (20200501); C10M
2201/02 (20130101); C10M 2229/05 (20130101); C10M
2207/286 (20130101); C10N 2040/241 (20200501); C10N
2040/245 (20200501); C10M 2209/11 (20130101); C10M
2211/042 (20130101); C10N 2050/01 (20200501); C10N
2040/244 (20200501); C10N 2040/246 (20200501); C10N
2040/247 (20200501); C10M 2229/02 (20130101); C10M
2207/281 (20130101); C10M 2215/04 (20130101); C10M
2209/107 (20130101); C10M 2215/26 (20130101); C10M
2209/104 (20130101); C10M 2211/06 (20130101); C10N
2070/02 (20200501); C10M 2209/105 (20130101); C10M
2207/30 (20130101); C10N 2040/22 (20130101) |
Current International
Class: |
C11C
3/04 (20060101); C11C 3/08 (20060101); C11C
3/00 (20060101); C11c 003/10 (); C11c 003/00 ();
C10m 001/26 () |
Field of
Search: |
;260/404.8,410.6,410.7 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Gotts; Lewis
Assistant Examiner: Rivers; Diana G.
Parent Case Text
This application is a Division of Ser. No. 834,556, filed June 18,
1969 now U.S. Pat. No. 3,634,245.
Claims
I claim:
1. A water soluble lubricant composition obtained by
transesterifying at a temperature of from about 400.degree. to
450.degree.F. and in the presence of a buffer catalyst 1 mole of
castor oil with from 0.75 to 2.0 moles of polyoxyalkylene polyol
having a molecular weight of at least about 1,000 until the
reaction products are water soluble and then esterifying the
hydroxy compounds present with a carboxylic or dicarboxylic acid
until the acid number of the product is below six.
2. A composition as in claim 1 where the molar ratio of castor oil
to polyoxyalkylene polyol is 1:1 and the carboxylic acid is
phenylstearic acid.
3. A composition as in claim 1 where the molar ratio of castor oil
to polyoxyalkylene polyol is 1:1 and the carboxylic acid is
monosodium azelate.
4. A composition as in claim 1 where the polyoxyalkylene polyol is
a polyethyleneoxy, polypropyleneoxy polyol of molecular weight of
about 3,000, the molar ratio of castor oil to said polyol is 1:1,
the buffer catalyst is sodium acetate, and the acid is stearic.
Description
Metal working lubrication has been accomplished, as is well known,
by the use of mineral and/or fatty oils. In the early technology,
these fats and oils were used alone, but with the advent of
improved technology, it was useful to prepare aqueous emulsions of
mineral and/or fatty oils in order to reduce costs, improve cooling
capacity, and give generally better performance. Until recent years
almost all water containing lubricants were emulsions of fatty
and/or mineral oils which might or might not contain various
additives for particular applications. However, emulsion type
products have several inherent problems, as, for example, emulsion
stability, and for this reason and others they often find their
utility limited. In recent years, water containing lubricants of
the solution type have become available and in areas where cooling
ability is the primary consideration the water soluble lubricant
has shown great merit. However, where conditions require both a
high degree of cooling plus a high degree of hydrodynamic or oil
film lubricity characteristics, the water soluble lubricants have
not been suitable because they have been unable to deposit a film
containing sufficient lubricity for proper function under
hydrodynamic conditions.
The water soluble lubricants appear to function by "plating out"
the lubricant onto the surface to be lubricated during use. This
appears to occur because heat of friction raises the temperature of
the solution above its cloud point and causes the solution to
change to a dispersion or emulsion, whereby the "plating out"
phenomena occurs. In the past, however, the lubricating benefit
derived from the film of"plate out" of these aqueous solution
lubricants has been well below the degree of lubricity provided by
the conventionally emulsified materials.
This invention now provides an improved water soluble lubricant
which deposits a film on surfaces to be lubricated where the
deposited film has greatly improved lubrication and anti-frictional
qualities.
In one embodiment of the invention there is provided a water
soluble product obtained by transesterifying a triglyceride such as
castor oil or similar triglyceride with a polyoxyalkylene polyol
until the reaction products are water soluble and then esterifying
the hydroxy compounds present with a carboxylic or dicarboxylic
acid.
Another embodiment of the invention involves an aqueous solution
formulation useful as a metal working lubricant. Still another
embodiment of the invention is the process for lubricating metal by
providing on its surface a lubricating film of the water soluble
lubricant composition above defined.
In making the compositions of the invention, a first step requires
the transesterification of the triglyceride, preferably castor oil,
with a polyoxyalkylenepolyol having a molecular weight of at least
about 1,000 until the reaction products are water soluble. As is
well known, castor oil is a triglyceride which is predominantly the
ricinoleic acid ester of glycerol, but which contains minor amounts
of the oleic and linoleic esters. Thus, in the transesterification
step, the polyoxyalkylene polyol will replace some or all of the
glycerol OH groups and generate OH groups from the glycerol. The
free OH groups in this water soluble product are then reacted with
a carboyxlic acid or a dicarboxylic acid to prepare the product
which is subsequently formulated for use as will be discussed
below.
In the transesterification procedure, the preferred amount of
polyoxyalkylene polyol used will be on an approximate 1:1 mole
equivalent weight ratio with the triglyceride. At higher content of
polyoxyalkylene polyol there will be a decrease in the lubricity
value afforded by the end product. At significantly lower content
of polyoxyalkylene polyol, water solubility will not be achieved.
The effective range for water solubility and good lubricity is 0.75
to 2.0 mole equivalents of the polyoxyalkylene polyol to 1.0 mole
equivalent of the triglyceride.
In carrying out this transesterification step, it is preferred to
remove air from the reaction medium and this is done preferably by
sweeping nitrogen through the reaction equipment. The temperature
of the transesterification process is on the order of 400.degree.
to 450.degree.F. and the time of reaction will, of course, vary
with reaction kettle size and other factors, but, in general, will
be from about 10 to 20 hours. Completion of the reaction is
determined when 5 g. of the product is completely soluble in 100
ml. of water at 100.degree.F. The polyoxyalkylene polyol used in
the reaction may be any one of a large number of such products
which are commercially available, but for use in this invention,
the glycol used will have a molecular weight of at least about
1,000. If glycols of molecular weight less than this are used, the
products are not water soluble and not useful in this invention. As
a simple example of such materials that may be used reference is
made to polyethyleneglycol. Other polyoxyalkylenepolyols may be
used such as the water soluble high molecular weight viscous liquid
polyalkylene polyols which contain ethylene oxide and/or propylene
oxide groups available as "Pluracol" V-5 and V-7 manufactured by
Wyandotte Chemicals Corporation or the polyalkylene glycols known
as "Ucons" available from Union Carbide Chemicals Company.
The transesterification is carried out generally in the presence of
a catalyst. The catalyst used is an important factor in achieving
water solubility of the transesterification reaction product.
Buffer catalysts such as alkali metal carbonates and acetates,
(e.g., sodium carbonate, sodium acetate, and the like) are
necessary. Acidic and basic catalysts produce a product with only
partial water solubility.
When the transesterification reaction is completed as indicated by
the above water solubility test, reaction of the first product is
made to occur with the carboxylic or dicarboxylic acid and such
acids may be any of the well-known long-chain fatty acids such as
lauric, oleic, stearic acid, ricinoleic, linoleic and the like.
Dicarboxylic acids which may be used are succinic, adipic, glutaric
azelaic, and sebacic. Also useful are aryl substituted fatty acids
such as phenylstearic and the like.
In this second reaction step, a catalyst is also preferably used
and p-toluenesulfonic acid or similar acidic catalyst (e.g.,
dodecylbenzenesulfonic acid, etc.) is employed. The temperature of
the reaction may be from about 350.degree. to 450.degree.F. and
reaction is continued by stirring the reactants at this temperature
until completion of the reaction which is indicated by the acid
number falling below to six.
The resulting product obtained by the above procedure is a viscous,
amber fluid, soluble in 100.degree.F. water with distinct cloud
points below 180.degree.F. and gives a pH in a 5 percent water
solution of 7.0 to 7.7. This product is used by dilution with water
and this formulation may also contain other additives as e.g.,
agents for rust protection, silicone polymers as defoamers,
chlorinated phenol type bactericides and the like. Generally, the
formulation of product in water will be such that the amount of
lubricant will be on the order of 5 to 50 percent by weight and
preferably 10 to 25 percent.
In order to further illustrate the invention the following examples
are given:
EXAMPLE 1
A stainless steel reaction vessel is charged with 20 pounds of
castor oil, 44.5 pounds of polyalkylene polyol containing ethylene
oxide and propylene oxide groups and having a molecular weight of
about 3,000 (Pluracol V-5) and 0.15 pounds of sodium acetate. The
reaction vessel is swept with nitrogen at a rate of 5 to 10 cubic
feet per hour and as the mixture is agitated the temperature is
raised to 425.degree.F. After 17 hours at this temperature a sample
is taken and 5 percent by weight solution of the product in water
at 100.degree.F. is readily obtained. The temperature of the
reaction mixture is then reduced to 375.degree.F. and 5.5 pounds of
phenylstearic acid (Armour Neofat LPS) and 0.18 pounds of p-toluene
sulfonic acid is added. The temperature is raised to 420.degree.F.
and after the acid number reaches 3.8 (about 24 hours) the heat is
removed and when the temperature drops to about 200.degree.F. the
reaction mixture is discharged into containers for storage and
subsequent use. The product is an amber fluid that has the
following typical properties:
Acid number 4.0 Hydroxyl Number 62 Saponification Number 68 Color
[FAC] 7 Flash Point [COC] 565.degree.F. Fire Point [COC]
615.degree.F. Specific Gravity 1.04 at 60.degree./60.degree.F.
Viscosity at 100.degree.F. 2725 sus Viscosity at 210.degree.F. 410
sus Viscosity Index 132
EXAMPLE 2
A stainless steel reactor is charged with 21.1 pounds of castor oil
and 45.3 pounds of Pluracol V-5 and 0.17 pounds of sodium acetate.
Nitrogen is swept through the reaction kettle at 5 to 10 cubic feet
per hour and the temperature of the reactants is raised to
400.degree. to 450.degree.F. while maintaining agitation. This
temperature is held for approximately 17 hours at which time a 5
percent by weight solution of the product in water at 100.degree.F.
is obtained as a clear solution. At this point the temperature of
the reaction product is lowered to 380.degree.F. and 3.3 pounds of
monosodium azelate and 0.07 pounds of dodecyl benzene sulfonic acid
are added. The reaction mass is maintained at 380.degree. to
420.degree.F. with a nitrogen sweep being maintained for
approximately 20 hours after which time an acid number of 3.5 is
reached. The product is an amber fluid that has the following
typical properties:
Acid Number 3.8 Hydroxyl Number 61.5 Saponification Number 71.2
Color [FAC] 20 Flash Point [COC] 560.degree.F. Fire Point [COC]
610.degree.F. Specific Gravity 1.04 at 60.degree./60.degree.F.
Viscosity at 100.degree.F. 3067 sus Viscosity at 210.degree.F. 436
sus Viscosity Index 129
EXAMPLE 3
Example 1 is repeated except that the phenylstearic acid is
replaced with stearic acid and the product obtained has the
following properties:
Acid Number 3.21 Hydroxyl Number 61 Saponification Number 69.3
Color [FAC] 2 Flash Point [COC] 625.degree.F. Fire Point [COC]
640.degree.F. Specific Gravity 1.03 at 60.degree./60.degree.F.
Viscosity at 100.degree.F. 3059 sus Viscosity at 210.degree.F. 464
sus Viscosity Index 130
EXAMPLE 4
Example 1 is repeated except that the Pluracol V-5 is replaced with
47.2 pounds of polyethylene glycol of 2,500 molecular weight (Ucon
75-H-1400). The fluid product obtained from this reaction has the
following typical properties:
Acid Number 4.2 Hydroxyl Number 63 Saponification Number 57.6 Color
[FAC] 3 Flash Point [COC] 525.degree.F. Fire Point [COC]
620.degree.F. Specific Gravity 1.04 at 60.degree./60.degree.F.
Viscosity at 100.degree.F. 1687 sus Viscosity at 210.degree.F. 252
sus Viscosity Index 133
As indicated, the above compositions are used primarily as
lubricants in the metal working field. For this purpose the
products are formulated with water and such formulations will
contain from about 5 to about 50 percent by weight of the active
lubricant. The following example illustrates the type of lubricant
formulations which may be employed.
EXAMPLE 5
The lubricant composition of Example 1 is formulated for sale as a
concentrate as follows:
Parts by Weight Water 74.58 Antirust agent 0.30 Tri-sodium salt of
ethylenediamine- tetra acetic acid 0.10 Sodium salt of
pentachlorophenol 0.02 Product of Example 1 25
The above formulation is very effective as a mold release agent in
the die casting of aluminum.
In carrying out the mold release use for the product, a solution
of40 parts of water to 1 part of the above formulation was applied
to the die by hand spray prior to closing the die and then
injection of approximately 2 pounds of molten aluminum at
1,200.degree.F. was made. Casting time was 6 seconds with an
approximate pre-injection die temperature of 450.degree.F. The part
cast was the body of a saber saw. When the die was open no sticking
of the part to the die was experienced and the equality of the
surface of the cast part was considered good. In a comparative test
where the mold release agent was composed of a higher cost
colloidal graphite in water, the graphite product gave good mold
release at comparable dilution, but resulted in poorer surface of
the cast part.
The products of the invention are also useful in the cold reduction
of steel where the lubricant formulation is used at dilutions of
about 8 to about 25 parts of water to one part of the formulated
product Likewise, in the hot reduction of steel, thelubricant may
be used as an additive to the cooling water used on the mill at a
concentration of from 0.01 to 0.5 percent or may be applied to the
rolls in the mill from a separate system at a concentration in
water of from 1 to 20 percent parts by weight.
In chip forming metal working, the formulations of the invention
will be used as concentrations in water of from 1 to 20 percent of
various cutting and grinding operations of ferrous and non-ferrous
metals. Likewise, in wire drawing of ferrous and non-ferrous
metals, the lubricant is useful at concentrations in the water of 5
to 15 percent to draw copper, steel, and copper coated steel wire.
In metal deformation processes, the formulations may be used as
concentrations of from 10 to 100 percent in water for lubrication
of the deep drawing of metal. The lubricants are also useful in hot
working and other procedures well known in the trade.
The compositions of the invention generally provide excellent
cooling, and excellent uniform lubrication, resulting in a more
uniform surface of the work metal, easier cleaning of the residual
film of lubricant and a greater economy owing to the longer life of
the lubricant solution due to the greater immunity to change of the
operating parameters. By using the lubricants, of the invention
good tool life, good finish on the machine part, and good
lubrication in moving parts is generally achieved. The lubricant of
the invention has excellent ability to deposit a film on a hot
surface making it a particularly good lubricant for hot working of
metals such as forging, hot rolling, and die casting.
The lubricants of the invention are also of value as a rubber
parting agent in extrusion of crude rubber and steam curing, and
are able to replace the conventional soap/silicone polymer mixtures
used heretofore. In order to further illustrate the characteristics
of the lubricants of the invention, the following test results are
given in the table which follows: ##SPC1##
* * * * *