U.S. patent number 3,729,415 [Application Number 05/097,294] was granted by the patent office on 1973-04-24 for lubricating composition.
This patent grant is currently assigned to Joseph E. Ferri. Invention is credited to William J. Davis, Richard C. Gilles.
United States Patent |
3,729,415 |
Davis , et al. |
April 24, 1973 |
LUBRICATING COMPOSITION
Abstract
Lubricating composition comprising a hydrocarbon oil and
polyethylene having an average molecular weight within the range of
from over 1 million to about 5 million, the composition being of
various forms, namely a fluid-like gel, a jelly-like gel and a
rigid gel, depending on the amount of polyethylene present in the
composition.
Inventors: |
Davis; William J. (Wyomissing,
PA), Gilles; Richard C. (Sinking Spring, PA) |
Assignee: |
Ferri; Joseph E. (Schillington,
PA)
|
Family
ID: |
27492903 |
Appl.
No.: |
05/097,294 |
Filed: |
December 11, 1970 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
771273 |
Oct 28, 1968 |
3547819 |
|
|
|
668692 |
Sep 18, 1967 |
|
|
|
|
486214 |
Sep 9, 1965 |
|
|
|
|
363294 |
Apr 28, 1964 |
|
|
|
|
Current U.S.
Class: |
508/167; 585/4;
585/13; 508/462; 508/554; 508/591; 508/579; 585/2; 585/12 |
Current CPC
Class: |
C10M
1/08 (20130101); C10N 2030/32 (20200501); C10M
2209/102 (20130101); C10M 2201/05 (20130101); C10M
2205/14 (20130101); C10M 2205/02 (20130101); C10M
2217/044 (20130101); C10M 2207/04 (20130101); C10N
2040/16 (20130101); C10M 2205/026 (20130101); C10M
2209/10 (20130101); C10M 2207/32 (20130101); C10M
2201/066 (20130101); C10M 2205/024 (20130101); C10M
2201/04 (20130101); C10M 2217/045 (20130101); C10M
2207/404 (20130101); C10N 2050/02 (20130101); C10M
2209/00 (20130101); C10M 2209/02 (20130101); C10N
2040/17 (20200501); C10M 2205/00 (20130101); C10N
2020/01 (20200501); C10M 2205/022 (20130101); C10M
2207/40 (20130101); C10N 2040/02 (20130101); C10N
2050/10 (20130101) |
Current International
Class: |
C10m 001/18 ();
C10m 001/10 (); C10m 005/08 () |
Field of
Search: |
;252/12.,12.2,12.4,12.6,25,51.5A,56S,59 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wyman; Daniel E.
Assistant Examiner: Vaughn; I.
Parent Case Text
This is a continuation of application Ser. No. 771,273, filed Oct.
28, 1968, now U.S. Pat. No. 3,547,819, which is a
continuation-in-part of abandoned application Ser. No. 668,692,
filed Sept. 18, 1967, which is a continuation of abandoned
application Ser. No. 486,214, filed Sept. 9, 1965, which in turn is
a continuation-in-part of abandoned application Ser. No. 363,294,
filed Apr. 28, 1964.
Claims
We claim:
1. A lubricating composition comprising a hydrocarbon oil of
lubricating viscosity and polyethylene having an average molecular
weight within the range of about 1.5 million to about 5 million
wherein said ingredients are present in proportions such that the
composition is a jelly-like gel.
2. A composition according to claim 1 wherein said oil is mineral
oil.
3. A composition according to claim 1 wherein the molecular weight
of said polyethylene is within the range of about 1.5 million to
about 3.5 million.
4. A composition according to claim 1 wherein the amount of said
oil comprising said composition is about 95 to less than about 99%
by weight and wherein the amount of said polyethylene comprising
said composition is greater than about 1 to about 5 percent by
weight.
5. A composition according to claim 1 comprising about 79 to about
99 percent by weight of said oil; greater than about 1 to about 5
percent by weight of said polyethylene; and about 1% to about 20
percent by weight of filler.
6. A composition according to claim 5 wherein said filler is a
finely divided material selected from the group consisting of
molybdenum disulfide; nylon; polyaryl carbonate and polyacetal.
7. A composition according to claim 5 wherein said oil is a mineral
oil.
8. A composition according to claim 7 wherein the molecular weight
of said polyethylene is about 1.5 million to about 3.5 million.
9. A jelly-like gel lubricating composition comprising about 95 to
less than about 99 percent by weight of a mineral oil of
lubricating viscosity and greater than about 1 to about 5 percent
by weight of polyethylene having an average molecular weight within
the range of of about 1.5 million to about 5 million.
10. A composition according to claim 9 wherein the molecular weight
of said polyethylene is within the range of about 1.5 million to
about 3.5 million.
Description
In a related application, namely Ser. No. 771,348, filed on Oct.
28, 1968, and now U.S. Pat. No. 3,541,011, there is described and
claimed lubricating compositions containing a lubricant,
polyethylene having an average molecular weight within the range of
from over 1,000,000 to about 5,000,000 and, in addition, a
polyethylene having a molecular weight of 1,000,000 or less.
There is a great demand and a long-felt need in every industry for
a lubricating product which, once used as a lubricating medium in
an object, is lubricant-releasing and imparts a long-lasting
self-lubricating quality to the object. For example,
self-lubricating bearings are extremely useful in the automotive
industry, the aviation industry, and almost anywhere bearings are
used. If such lubricating product has a mechanical strength
sufficient to be a part of the structure of the object for which it
is a lubricant, then, not only the self-lubricating quality of the
object achieved, but the object also can be produced easily,
economically and without the usual problems of manufacturing.
Accordingly, an object of this invention is to fulfill the
long-felt need for the lubricating product by providing a
lubricating composition which is simple, economical and easy to
use.
Another object of this invention is to provide a lubricating
composition the viscosity of which may be varied within a wide
range.
Another object of this invention is to provide a lubricating
composition comprising a lubricant and a high molecular weight
polyethylene.
Another object of this invention is to provide a lubricating
composition which has sufficient mechanical strength to form all or
a portion of the structure of an object.
Another object of the present invention is to provide a lubricating
material for an object to impart a long-lasting self-lubricating
quality to the object.
Another object of this invention is to provide a lubricating
composition that can be poured and set up in situ. These and other
objects and advantages of this invention will become apparent and
best understood from the following description and appended
claims.
The term "self-lubricating" as used herein in connection with an
object, such as a bearing, indicates that a continuous or
periodical supply of a lubricant from an external source to the
object is unnecessary. The percentages of different materials used
herein are all based on the total weight of the composition of this
invention. The terms "molecular weight" as used herein denote
average molecular weight. The terms "high molecular weight" as used
herein denote a molecular weight of from over 1.0 .times. 10.sup.6
to about 5.0 .times.10.sup.6. The terms "lower molecular weight" as
used herein denote a molecular weight of 1,000,000 or less, for
instance, between about 1,000 and 100,000.
Briefly, it has been discovered that a gel composition comprising a
polyethylene having a high molecular weight, that is a molecular
weight within the range of from over 1,000,000 to about 5,000,000,
and a lubricant, such as a hydrocarbon oil, is a long-lasting
lubricating medium. The higher the molecular weight of the high
molecular weight polyethylene and/or the higher the amount of high
molecular weight polyethylene in the composition, the firmer and
more viscous is the gel composition. Thus, depending upon the
specific molecular weight of the high molecular weight polyethylene
and the specific amount thereof in the composition, the physical
characteristics of the composition vary and range from a thin, weak
gel which behaves as a liquid to a firm, tough, rigid gel which
looks like and functions as a solid. The intermediate composition
between the weak gel and the rigid gel can be characterized as a
jelly-like gel.
In storage, the composition of this invention has the capability of
retaining the lubricant for as long as desired. Upon use as a
lubricating medium for an object, such as a solid lubricant for a
bearing, the composition is continuously and gradually
lubricant-releasing for the life of the object and imparts a
long-lasting, self-lubricating quality to the object. The firm,
rigid gel can be, if desired, produced and adapted to function as a
part of the structure of the object for which it is a lubricating
medium. For instance, the lubricating composition may form the
socket portion of a ball joint comprising a ball and a socket and,
at the same time, can lubricate the surface of the ball.
The amount of the high molecular weight polyethylene employed in
the gel composition depends upon the desired viscosity, toughness,
and strength of the composition. As stated hereinabove, the higher
the amount of the high molecular weight polyethylene in the
composition, the more viscous and stronger is the gel. For
instance, the gel behaves as a liquid when up to about 1 percent of
the high molecular weight polyethylene is used. The mere presence
of the high molecular weight polyethylene in the gel has an
influence on its properties. However, it is desirable that the
liquid gel composition contain at least about 0.5 percent of the
high molecular weight polyethylene in order to realize fully the
benefits gained by adding it to the oil. The gel behaves as a
gelatinous jelly-like composition when from greater than 1 percent
to about 5 percent of the high molecular weight polyethylene is
used. The gel is rigid and functions as a solid when from over 5
percent to about 90 percent or higher of the high molecular weight
polyethylene is used to form the gel. It has been found that the
structural strength of the rigid gel composition is excellent when
the amount of high molecular weight polyethylene is within the
range of about 25 percent to about 85 percent. Consequently, in
applications where structural strength of the composition is
important, it is preferred that the composition contain about 25-85
percent of high molecular weight polyethylene. In applications
where structural strength of the rigid gel composition is not of
primary importance, amounts of high molecular weight polyethylene
within the range of about 8 percent to about 40 percent can be used
advantageously.
Surprisingly, it has been found that the inclusion of a lower
molecular weight polyethylene, that is one having a molecular
weight of 1,000,000 or less, in the gel composition of this
invention modifies the lubricant-retaining and lubricant-releasing
characteristics of the gel. (As mentioned hereinabove, lubricating
compositions containing the lower molecular weight polyethylene in
combination with a lubricant and a higher molecular weight
polyethylene are described and claimed in U.S. Pat. No. 3,541,011
issued Nov. 17, 1970.) Such modification in the lubricating quality
of the gel is especially advantageous when the composition is a
firm, rigid gel and is to be used as a part of the structure of a
self-lubricating object, for instance, a bearing. More
specifically, the presence of the lower molecular weight
polyethylene causes a slow down in the rate at which the lubricant
is dispensed from the composition. By varying the amount of lower
molecular weight polyethylene in the composition, there can be made
compositions which have different lubricant dispensing rates for
particular applications.
The molecular weight of the lower molecular weight polyethylene
employed in a gel composition is preferably much lower than that of
the high molecular weight polyethylene, for example, between about
1,000 to about 100,000.
Most preferably, the molecular weight of the lower molecular weight
polyethylene is within the range of about 20,000 to about 50,000.
Compositions containing polyethylene within this molecular weight
range have been found to have very desirable oil-releasing
characteristics for the various applications in which the
composition can be used.
The amount of the lower molecular weight polyethylene to be used to
produce the thin, weak gel can vary; however, the preferred amount
is within the range of about 0.25 percent to about 1 percent. In a
liquid gel composition which contains a lower molecular weight
polyethylene, the amount of high molecular weight polyethylene can
be as low as 0.25 percent. It is also preferred that the total
polyethylenes in the liquid gel composition be not more than about
1 percent. The amount of the lower molecular weight polyethylene in
the jelly-like composition and the rigid gel composition can vary;
however, it is preferred to use, respectively, up to about 10
percent, and up to about 40 percent of the lower molecular weight
polyethylene. Most preferably the jelly-like composition should
contain about 1 percent to about 5 percent of the lower molecular
weight polyethylene. Most preferably, the rigid gel should contain
about 1 percent to about 15 percent of lower molecular weight
polyethylene.
The amount of the lubricant to produce the thin, weak gel, the
jelly-like gel, and the rigid gel of this invention can vary over a
wide range. However, it is preferred to employ, respectively, about
99 percent or higher, from about 95 percent to less than 99
percent, and from about 10 percent to less than 95 percent of the
lubricant.
The unique properties of the composition of this invention allow it
to be prepared in a variety of ways, each of which has its
particular advantages. In general, the process of producing the
composition of this invention is simple and comprises admixing the
high molecular weight polyethylene, preferably in powdered or flake
form, with a lubricant, for example, a mineral oil, heating the
mixture, with or without stirring or agitation, to a sufficient
temperature high enough to cause melting of the polymer component
thereof and for a time sufficient to obtain a homogeneous mixture
of polyethylene and lubricant. Upon cooling, the homogeneous
mixture or mass forms the gel composition of this invention. The
viscosity and strength of the composition depend, as described
hereinabove, on the molecular weight of the high molecular weight
polyethylene employed and the amount thereof.
The temperatures employed to heat a mixture of a high molecular
weight polyethylene and a lubricant in the method of this invention
are sufficiently high to melt and cause mixing of the components of
the mixture. In general, the heating temperatures employed range
between about 240.degree.F. and 450.degree.F.; however, the
temperatures should not be high enough to cause thermal
decomposition. When the mixture begins to form into a homogeneous
mass, it will be observed that for a composition which contains
about 5 percent or more high molecular weight polyethylene, there
is obtained a thick cohesive, but flowable, composition. On the
other hand, when the high molecular weight polyethylene comprises
less than about 5 percent of the composition, there is obtained a
thin fluid mixture at the temperature of homogeneous mass
formation.
After the components have blended into a homogeneous composition
within the temperature range of about 240.degree.F. to
450.degree.F., the composition should then be allowed to cool. When
preparing the jelly-like and rigid gels, it will be observed that
as the homogeneous mass is cooled, it will begin to take on the
appearance of its final form at a temperature generally within the
range of about 200.degree.F. to about 300.degree.F. This is the
temperature transition range where the homogeneous mass begins to
change from a flowable state to a solid jelly-like or rigid
state.
During the heating of a mixture of high molecular weight
polyethylene and lubricant, it is preferred to agitate the mixture
to cause better mixing so that the polyethylene does not settle out
of the mixture. Any conventional method of producing the mixing,
such as in an ordinary extruder or sigma mixer is satisfactory. A
conventional laboratory propeller-type mixer can be used
conveniently when preparing the fluid-like gels.
Another important advantage that is realized when the
polyethylene/lubricant mixture is agitated or mixed as it is being
heated is that the overall time for preparing the gel composition
can be shortened. In this connection it is noted that the time for
preparing the composition will depend upon a number of variables,
including the overall amount of the composition that is being
prepared and the manner in which the components are mixed and
heated during the preparation. By way of example, it can take from
about 5 to 10 minutes to prepare about 1,000 grams of the
composition by hand mixing. Longer mixing and heating times may be
required to prepare larger batches of the composition. On the other
hand, large amounts of the composition can be prepared in less time
if an extruder is used as, the heating and agitating device. If the
polymer/lubricant components are not agitated during the heating
stage, it generally takes about 45 to about 60 minutes before the
components blend into a homogeneous mass.
There are applications, however, where that characteristic of the
composition of this invention which enables it to be prepared
without stirring during the heating stage of preparation is
extremely important. For example, in many applications wherein it
is expedient that the rigid gel composition be made by molding it
in situ to form a self lubricating object, for example by
encapsulating multiple bearings in a housing, it is very difficult,
if not impossible to stir and agitate the mixture due to the size
or shape of that mold. Whereas heretofore known polymer/lubricant
compositions which require stirring and agitation for preparation
would hardly be suitable for such applications, the composition of
this invention can be used very suitably and to good advantage.
Thus, at the expense of a somewhat longer preparation time, the
unique properties of the composition of this invention which allow
it to be prepared by simply heating without stirring enable it to
be used in applications where the use of known polymer/lubricant
compositions would be attended by difficult problems. As will be
shown in connection with the examples reported below, attempts to
prepare lubricating compositions containing oil and a polyethylene
of molecular weight lower than about one million, by simply heating
a mixture of the oil and polyethylene have shown that the
preparation of a homogeneous composition was attained only after
heating the mixture for a much longer period of time than that
needed to prepare the composition of this invention.
Another and preferred method of producing the rigid, tough gel
composition of this invention comprises first preparing a
homogeneous fluid-like, thin, weak gel composition of the high
molecular weight polyethylene, in accordance with the method of
this invention described hereinabove, and then mixing additional
high molecular weight polyethylene with the weak gel composition to
obtain a liquid dispersion mixture thereof. (This dispersion
mixture is stable over a relatively long period of time, that is
the polyethylene does not tend to settle out of the liquid
dispersion mixture.) This dispersion mixture is heated with or
without stirring to a temperature sufficient to melt the mixture,
preferably between about 240.degree.F. and 450.degree.F. The heated
mixture forms the desired rigid composition upon cooling to a
temperature sufficient to solidify it. This usually occurs at a
temperature between about 200.degree.F. and 300.degree.F. The
amount of the high molecular weight polyethylene dispersed in the
weak gel composition should be sufficient to produce the desired
rigidity and toughness for the final gel product. In any event, the
total amount of high molecular weight polyethylene in the rigid gel
should be the same as that described hereinabove for a rigid gel
composition of this invention.
An advantage that is realized by preparing the rigid gel
composition of this invention according to the preferred method set
forth immediately above is that the above described stable
dispersion mixture can be shipped in liquid form by a formulator to
a manufacturer or processer who can then convert the liquid
dispersion mixture, be heating and cooling as described, into a
rigid self-lubricating object of any desired shape. It is noted
that if an amount of high molecular polyethylene in excess of about
5 percent is combined with a lubricant and dispersed therein, it
will be found that the polyethylene tends to settle out in a
relatively short period of time, that is, it is not a stable
dispersion as is the stable dispersion described above. As a
consequence, one is confronted with handling problems when this
type of dispersion is shipped from the formulator to the
manufacturer or processer.
The rigid, tough gel composition of this invention can be easily
adapted to be a part of the structure of a self-lubricating object,
such as an anti-friction bearing. In this manner, not only the
rigid gel composition is a structural part of the object, such as
the retainer and/or seal, but also it is continuously and gradually
lubricant-releasing for the life of the object and imparts a
long-lasting, self-lubricating quality to the object. For instance,
to adapt the rigid composition to be a part of the structure of a
bearing, a dispersion mixture of a weak gel composition of this
invention and a high molecular weight polyethylene is prepared as
described above and used to fill the space between the inner and
outer rings of the bearing, i.e., the space in which the rolling
elements of a bearing are located. The bearing which is filled with
the dispersion mixture can be heated to a temperature between
240.degree.F. and 450.degree.F. without stirring. The heated
dispersion mixture in the bearing is then cooled to solidify the
mixture, thereby forming a rigid, strong portion of the bearing.
The rigid gel in the bearing tends to eliminate the need for a
retainer and/or seal for the rolling elements and the oil which
exudes from the gel lubricates the bearing. Such bearing can be
used in any conventional manner, such as to support the shaft in an
electric motor.
The composition has the capability of being poured and molded in
situ for uses such as electrical insulation for cables and as an
encapsulating material for electronic components. The product of
this invention has high voltage breakdown and self-healing
characteristics and with certain additives, such as boron, it is a
shielding material for nuclear reactors. The composition of this
invention can be used in other applications depending upon the
physical properties and characteristics of the composition. For
instance, the weak gel composition which behaves like a liquid is
useful in the lubrication of gear trains or as a motor oil which
substantially reduces the wear and tear of a motor. The gelatinous,
jelly-like composition is useful in the lubrication of porous or
non-porous sleeve, ball, and roller bearings. Present methods for
lubricating porous and non-porous sleeve bearings involve the use
of a reservoir which holds a felt or fibrous material which is
impregnated with oil which is fed by capillary action to the
bearings. The compositions of the present invention can be
substituted for the oil impregnated felt or fibrous materials and
will function to lubricate the bearings in a manner such that the
disadvantages inherent in the use of felt and fibrous materials are
avoided.
The rigid gel composition not only can be used in forming the
self-lubricating bearing described above, but it can also be used
in producing different articles, such as the socket of a ball
joint. To form the socket by previous methods required high
precision which makes those methods expensive. It has been found
that an economical and easy method of producing the socket
comprises filling a container with the dispersion mixture of the
weak gel composition and a high molecular weight polyethylene,
heating the dispersion mixture in the container between about
240.degree.F. and 450.degree.F. to obtain a homogeneous mixture
thereof, inserting the ball into the container so that the
homogeneous mixture covers the surface of the ball or any desired
portion thereof, and cooling the homogeneous mixture to sufficient
temperature to solidify the mixture, thereby forming a rigid and
strong socket around the ball to produce the ball joint which is
easily removable from the container. The ball joint thus produced
is self-lubricating for the life thereof and has a strength
sufficient to be used as the socket of the ball joint for any
conventional application thereof.
Another extremely important property of the composition of this
invention is that the rigid gel composition is capable of being
molded by reciprocating screw injection machines of the types which
are used for molding thermoset resins. As is well-known for certain
applications, these types of molding machines have inherent
advantages over other types of molding machines. Whereas it is
impractical, if not impossible, to mold high molecular weight
polyethylene in the aforementioned reciprocating screw injection
machines, the rigid gel composition of this invention have
properties which enable the composition to be molded very
conveniently into a variety of shapes by said machines.
It should be understood that various additives normally used in
lubricants can be added to the composition of this invention. Other
additives, such as pigments and dyes, could also be used. However,
we have found that the addition of a small amount of a suitable
finely divided filler to the rigid composition of this invention,
minimizes any possible dimensional instability, such as shrinkage,
of the composition. The finely divided fillers should have a
particle size within the range of about -50 to about -325 U.S. mesh
and should have a relatively low coefficient of friction and be
nonabrasive for the material or article which is being lubricated.
Exemplary of such fillers are molybdenum disulfide; nylon powder,
the preparation of which is described in U.S. Pat. Nos. 2,639,278
and 3,022,542; Lexan which is the trademark of General Electric
Company for a polyaryl carbonate; and Delrin which is the trademark
of DuPont de Nemours and Company for a polyacetal. The amount of
the finely divided filler can vary over a wide range, and should be
sufficient to produce the desired result; however, it is preferred
to use between about 1 percent to about 20 percent of the
filler.
As mentioned above, the high molecular weight polyethylene
component of this invention has a molecular weight within the range
of from over 1 .times. 10.sup.6 to about 5.0 .times. 10.sup.6.
Although the molecular weight range of the polyethylene is from
over 1.0 .times. 10.sup.6 to about 5.0 .times. 10.sup.6, a
molecular weight range of from about 1.5 .times. 10.sup.6 to about
3.5 .times. 10.sup.6 is preferred.
Examples of high molecular weight polyethylenes are: a polyethylene
produced by Allied Chemical Co. under the trade designation AC-3X,
which has a particle size of about 40 mesh and a molecular weight
of about 3 .times. 10.sup.6 ; a polyethylene produced by Allied
Chemical Co. under the trade designation AC-1221, which has a melt
index of 0.00, particle size of less than 100 mesh screen, and an
average molecular weight of from about 1.5 .times. 10.sup.6 to
about 2.5 .times. 10.sup.6 ; and a polyethylene produced by
Hercules Powder Company under the tradename Hi-Fax 1900, which has
an average molecular weight of over 2 .times. 10.sup.6 and a melt
index of 0.01.
The melt index of the high molecular weight polyethylene is between
0.00 and less than about 0.1 as measured by ASTM D1238-62T.
The high molecular weight polyethylenes can be produced by any
conventional method. One method of producing the high molecular
weight polyethylenes is by a process using Ziegler catalysts as
described in a book entitled "Polyethylene" by R. A. V. Raff and J.
B. Allison, 1956, page 78.
Examples of the lower molecular weight polyethylenes are: a
polyethylene produced by Allied Chemical Company under the trade
designation of AC-6A, which has an average molecular weight of
2000, specific gravity of 0.92, a viscosity of 180 c.p.s. at
284.degree.F., and a melting point of 219.degree.-226.degree.F.; a
polyethylene produced by Allied Chemical Company under the trade
designation of AC-615, which has a molecular weight of 5,000,
specific gravity of 0.92, a viscosity of 4000 c.p.s. at
284.degree.F., and a melting point of 224.degree.-232.degree.F.; a
polyethylene produced by Allied Chemical Company under the trade
designation of AC-617, which has a molecular weight of 1500, a
specific gravity of 0.91, a viscosity of 100 c.p.s. at
284.degree.F., and a melting point of 210.degree.-217.degree.F; a
polyethylene produced by Eastman Chemical Company under the
tradename Tenite, which has a melt index of 7, a specific gravity
of 0.92, and a molecular weight of 23,000; and a polyethylene
produced by U.S.I. Chemical Company under the tradename of
Microthene (MN-718), which has a melt index of 22, a specific
gravity of 0.915, and an average particle size of less than 20
microns. The lower molecular weight polyethylenes can be produced
by different conventional methods which are well known in the
art.
The lubricant employed in the practice of this invention can be any
hydrocarbon oil which has a lubricating viscosity. Excellent
results have been obtained when the oil utilized is a mineral oil;
and mineral oils are the preferred oil component. The mineral oil
may be a solvent-extracted or a solvent-refined oil. Exemplary of
the hydrocarbon mineral oils are: Harmony oil No. 44 (SAE No. 10)
produced by Gulf Refining Co., which is a pure hydrocarbon oil
containing an antifoam additive, rust and oxidation inhibitors, and
has a viscosity of 150.2 SUS at 100.degree.F.; Insulating oil No.
10-C produced by General Electric Corporation; Sunoco 280 (SAE No.
20) produced by Sun Oil Co., which has a viscosity of 250-280 SUS
at 100.degree.F. and a specific gravity of 0.87 - 0.88; Gulf SAE 10
which is a regular motor oil and is produced by Gulf Oil Co.;
Security No. 71 (SAE No 40) produced by Gulf Oil Co., which is a
pure hydrocarbon oil containing no additives and has a viscosity of
610 SUS at 100.degree.F.: Security No. 53 (SAE No. 20) produced by
Gulf Oil Co., which is a pure hydrocarbon oil containing no
additives and has a viscosity of 305 SUS at 100.degree.F.; Kendall
oil 10W which is a regular motor oil; Shell oil No. 66602, bearing
infusion oil, produced by Shell Oil Co.; Harmony oil No. 41 (SAE
less than No. 20) produced by Gulf Oil Co., which is a pure
hydrocarbon oil containing additives, antifoam, rust and oxidation
inhibitors, and has a viscosity of 105 SUS at 100.degree.F.: and
Esso's Ultragear oil, SAE No. 90.
Although the hydrocarbon mineral oils are by far the preferred
lubricant component, other oils, including vegetable and animal
oils, of lubricating viscosity can be also used. In addition,
various of the synthetic oils comprising hydrocarbon groups can be
utilized.
The high molecular weight polyethylene component of the composition
of this invention is insoluble in such typical organic solvents as
benzene, toluene and decalin. Its solubility properties--or more
aptly its insolubility properties--are thus quite different from
the solubility properties of substantially lower molecular
polyethylenes which are soluble in one or more of the
aforementioned organic solvents and which are known to form
solutions--as opposed to gels--when combined with oil. Solubility
tests performed with polyethylenes of molecular weight within the
range of about 1.5 - 2.5 million (Allied Chemical Co. AC--1221)
have shown that it is insoluble at room temperature in benzene,
toluene and decalin and also that it is insoluble in these organic
solvents at their boiling point temperatures which are
176.degree.F., 230.degree.F., and 377.degree.F., respectively.
During the solubility testing, it was observed that the above
described high molecular weight polyethylene swelled in benzene at
176.degree.F.; and that in toluene at 230.degree.F. and in decalin
at 377.degree.F., there were obtained gelatinous mixtures. Upon
cooling each of the hot gelatinous mixtures it was observed that
some of the toluene and decalin separated from its corresponding
gelatinous mixture.
The following examples which are identified by a Roman numeral are
illustrative of compositions within the scope of this invention.
The examples which are identified by a Roman numeral and capital
letter, are illustrative of compositions containing oil and a
polymeric material other than polyethylenes having a molecular
weight within the range of over 1,000,000 to about 5,000,000 and
are set forth for comparative purposes. The examples serve to show
the very different types of compositions or properties thereof that
are obtained when utilizing the high molecular weight polyethylenes
of this invention as opposed to polyethylenes having lower
molecular weight or other polymers.
Example I below is illustrative of the rigid gel composition of
this invention and that method of preparation which requires
heating but no mixing.
EXAMPLE I
120 grams of a hydrocarbon mineral oil (Sunvis 941 -- Sun Oil Co.)
and 40 grams of polyethylene of molecular weight 1.5-2.5 million
(AC-1221 -- Allied Chemical.) were cold mixed until the
polyethylene particles were well distributed throughout the oil.
This mixture, which comprised 75 percent oil and 25 percent
polyethylene, was placed in a preheated oven at 350.degree.F. and
maintained therein for about 1 hour after which it was removed and
allowed to cool. The cool product was removed from the beaker. The
product which had assumed the cylindrical shape of the beaker was a
tough, solid, oil-exuding, rigid gel. Upon cutting a pie-shaped
piece extending the length of the cylindrical shape, visual
observation showed the composition appeared homogeneous throughout
and had a smooth, oily surface. A socket of a ball joint is a
product that could be made from the composition of Example I.
EXAMPLE IA
one hundred-twenty grams of a hydrocarbon mineral oil (Sunvis 941
-- Sun oil Co.) and 40 grams of polyethylene of molecular weight
500,000 (Hi-Fax 1806 -- Hercules) were cold mixed until the
polyethylene particles were well distributed throughout the oil.
This mixture, which comprised 75 percent oil and 25 percent
polyethylene was placed in a preheated oven at 350.degree.F. and
maintained therein for about 1 hour after which it was removed and
allowed to cool. The product was very different from the product
described in Example I above, although it was made in exactly the
same way and contained the same relative proportions of oil and
polymeric components. The product consisted of a very definite oily
liquid phase and a solid mass of polymer and oil phase which was
not nearly as tough as the product of Example I and which was much
more easily penetrated with a pointed object than the product of
Example I. Unlike the product of Example I, the product of Example
IA upon standing was observed to be unstable in that the top
surface of the polymer/oil mass, except for a small center area,
seemed to separate into small irregular shaped globs of material.
The aforesaid small center area diminished in size as it broke down
into the aforesaid globs upon continued standing. The small center
area was not nearly as tough and was much more easily penetrated by
a point instrument than the tough, rigid, homogeneous product of
Example I. Thus, it was observed that whereas the product of
Example I remained homogenous, tough, smooth and rigid, the product
of Example IA was not homogeneous upon preparation in that it
consisted of an oil phase, a very mushy top surface comprised of
small globs of oil and polymer, and a small center area that was
not nearly as tough as the product of Example I and that was also
unstable. The product of Example IA in this form would not be
suitable for use as the socket portion of a ball joint.
EXAMPLE IB
A composition consisting of the same components as Example IA was
prepared according to the same method set forth in Examples I and
IA, except that the mixture was heated for two hours rather than
one. The product upon standing was found to be of a solid mass that
had a very porous, oily surface from which globs of mushy-like
particles could be easily separated. Moreover, the surface of the
product was very easily penetrated by a pointed instrument. Thus,
this product, even though heated during preparation for 100% longer
than the product of Example IA or Example I, was not tough and
smooth-surfaced.
Example II below is illustrative of the preparation of a
self-lubricating product within the scope of this invention.
EXAMPLE II
Thirty-five grams of a polyethylene having a molecular weight of
1.5 .times. 10.sup.6 to 2.5 .times. 10.sup.6 were mixed with 65
grams of Harmony oil No. 44 (SAE No. 10) at room temperature. The
mixture was poured into the space between the inner and outer rings
of a ball bearing to cover the balls. The bearing was then covered
on the top and bottom with aluminum plates and heated at
350.degree.F. for 45 minutes in a forced air oven. The bearing was
then cooled to room temperature. The mixture in the bearing had
solidified to a tough, oil-dispensing, rigid composition. The balls
in the bearing had free and efficient movement and the bearing was
self-lubricating.
EXAMPLE IIA
Thirty-five grams of a polyethylene having a molecular weight of
23,000 were mixed well with 65 grams of SAE No. 10 oil while
heating to 300.degree.F. A non-stringy liquid solution was
produced. When the solution was cooled to room temperature a weak
solid was produced. Within 10 hours a substantial amount of the oil
slowly separated out from the solid and left a cake which was
easily crumbled to a powder. Thus, this composition was not similar
to the self-lubricating composition of Example II above.
As illustrative of the jelly-like gel compositions of this
invention, which can be processed to a grease-like consistency,
three compositions were made up and their oil separation properties
were tested in accordance with a standard grease test, namely ASTM
D-1742. The results of the test are reported in Table 1 below. The
oil comprising the compositions of Examples III, IV and V reported
in Table 1 was Sun Oil Company's Sunvis 941, a hydrocarbon mineral
oil, and the polyethylene in said compositions was of molecular
weight 1.5 - 2.5 million (AC 1221 -- Allied Chemical Company).
There is also reported in Table 1 below, for comparative purposes,
the compositions of Examples IIIA, IVA and VA, which compositions
were comprised of the same oil utilized in compositions III, IV and
V and a polyethylene having a molecular weight of 500,000 (Hi-Fax
1806 -- Hercules Powder Company).
Except as noted below, each of the compositions reported in Table 1
was made according to the same method. This method included heating
a mixture of the oil and polyethylene components in a container to
a temperature of 320.degree.F. - 350.degree.F. and maintaining the
composition within this temperature range for about 3 minutes. The
mixture was agitated continuously during the heating cycle. The
composition was then poured into trays and allowed to cool to room
temperature. Each of the compositions, except those of Examples IVA
and VA, was then passed through a meat grinder having a small mesh
screen of one-sixteenth inch diameter holes. Thereafter, Examples
III, IIIA, and IV and V were tested for oil separation properties.
The compositions of Examples IVA and VA, which were not passed
through the meat grinder, were not so tested, the reason for this
being given immediately following the table.
TABLE 1
Components of Composition weight % Oil Separation Polymer, Mol. Wt.
Test Ex. 1.5- No. Oil 500,000 2.5 Mil. ASTM D-1742
__________________________________________________________________________
III 99 1 16.8 IIIA 99 1 25.0 IV 97 3 9.7 IVA 97 3 V 95 5 6.9 VA 95
5
as mentioned above, the compositions of Examples IVA and VA, which
contained polyethylene of molecular weight 500,000 were not tested
for oil separation properties. The reason for this is that after
these compositions were cooled, they were found to be of two
phases, an oil phase and dispersed therein large hard lumps of
polyethylene. (Some of the lumps in composition VA were 2 inches
long.) Whereas compositions IV and V were homogeneous gel-like gels
which were capable of being converted into a homogeneous
composition of grease-like consistency by passing them through the
meat grinder, the compositions of IVA and VA were not homogeneous
gel-like compositions that were capable of being converted by the
grinder into a homogeneous composition of grease-like consistency.
It is further noted that attempts were made to prepare homogeneous
compositions containing the components of Examples IVA and VA by
heating the oil and polyethylene mixture to higher temperature,
that is above 320.degree.F. - 350.degree.F. and increasing the time
of heating and mixing. However, it was found that compositions
containing no lumps could be made utilizing the increased
temperatures and length of mixing time.
With respect to the compositions of III and IIIA reported in Table
1 above, it can be seen that the oil separation properties of
Example III of the composition of this invention were much
better--to the extent of being 30 percent lower. The significance
of this is that a lubricating grease composition made from the
composition of Example III would have a much longer lubricating
life than one made from the composition of Example IIIA.
EXAMPLE IVB
An oil-polymer composition wherein the polymer was isotactic
polypropylene was prepared. The composition was made from a mixture
containing 3 percent isotactic polypropylene and 97 percent Sunvis
941 oil by heating, while stirring the mixture, to a temperature of
about 350.degree.F. Upon cooling, there was obtained an oily liquid
phase which contained suspended undissolved globs of polypropylene.
With reference to Example IV in Table 1 above, which identifies a
homogeneous composition of grease-like consistency, it should be
appreciated that the isotactic polypropylene/oil composition was of
a vastly different type of product.
In the comparative tests reported in Table 2 below, the oil
viscosity and oil separation properties of a liquid-like gel
composition of this invention containing a polyethylene of
molecular weight 1.5 - 2.5 million (AC 1221 of Allied Chemical
Company) and a mineral oil were compared with those of a
composition consisting of a polyethylene having a molecular weight
of 500,000 (Hi-Fax 1806 of Hercules Powder Company) and a mineral
oil. The mineral oil in each of the compositions was Sunvis 941 of
Sun Oil Co.
Each of the compositions set forth in Table 2 below was prepared in
the same way. They were each prepared by heating a mixture of the
oil and polyethylene components to 320.degree.F. - 350.degree.F.
and maintaining the composition within this temperature range for
about 3 minutes. The mixture was agitated continuously during the
heating cycle. The composition was then cooled, placed in a mixing
bowl and blended with a wire heater at No. 8 speed for about 10
minutes. (A Kitchen Aid mixer Model K5-A was used.)
The viscosity of each of the compositions was then determined.
Also, each of the compositions was allowed to stand in a beaker for
over a month and periodic observations were made to determine
whether any oil separated from the composition. Upon observing that
a layer of oil separated from the composition, the depth of the
layer was measured with a ruler.
The results are reported in Table 2 below.
TABLE
2 Components of Composition, Wt. % Oil Separation Polymer, Mol. Wt.
in inches
__________________________________________________________________________
Ex. Visc. 1 8 18 35 1.5 - at 75.degree.F. day days days days No.
Oil 500 2.5 c.p.s. K Mil.
---------------------------------------------------------------------------
VI 99.5 0.5 1439 none none 1/32 1/32 VIA 99.5 0.5 925 none 1/8 1/8
1/8
__________________________________________________________________________
Prior to discussing the viscosity and oil separation properties
reported in the above table, it is first noted that small
undissolved particles of polyethylene were present in the
composition of Example VIA. On the other hand, the composition of
Example VI was clear and homogeneous throughout, and contained no
visible particles of polyethylene. In lubricating applications
wherein the lubricant had to pass through small openings, for
example screens or orifices, the composition of Example VIA could
tend to block the openings. This problem would not be encountered
using the composition of Example VI.
From the Table 2 above, it can be seen that the lubricating
composition within the scope of the invention had a viscosity of
over 55% greater than that of the composition of Example VIA. In
view of these results, it is evident that the addition of high
molecular weight polyethylene to oil in very small amounts is much
more effective in producing a composition of increased viscosity
than a polyethylene of lower molecular weight.
With respect to the stability properties of the compositions of
Examples VI and VIA, Table 2 shows that after 8 days, the
composition of Example VIA was unstable to the extent that a
one-eight inch layer of oil had separated from the composition. On
the other hand, after 18 days, there was only a one thirty-second
inch layer of oil on the top of composition VI. The significance of
this is that the composition of Example VI would have a much longer
lubricating life than that of the composition of Example VIA.
The following examples are further illustrations of the rigid gel
compositions of this invention.
EXAMPLE VII
Sixty-seven grams of Harmony oil No. 44 (SAE No. 10 oil) and 33
grams of polyethylene having a molecular weight of 1.5 .times.
10.sup.6 to 2.5 .times. 10.sup.6 were mixed at room temperature.
The mixture was poured in a 0.625 inch by 5.50 inch glass tube.
Both ends of the tube were covered. The filled tube was placed in a
preheated forced air oven at 350.degree.F. for 40 minutes. The
filled tube was removed from the oven and cooled for 5 minutes at
room temperature and quenched in a water bath. A gel composition
was obtained and removed from the tube. The result was a smooth,
tough, flexible and voidless composition which had assumed the
shape of the tube.
EXAMPLE VIII
Seventy-five grams of Security oil No. 53 (SAE No. 20 oil) and 25
grams of polyethylene having a molecular weight of 1.5 .times.
10.sup.6 to 2.5 .times. 10.sup.6 were mixed thoroughly and put in a
forced air oven at 300.degree.F. for 5 minutes. The mixture was
then removed from the oven and cooled to room temperature. The
result was a strong, uniform, solid product.
EXAMPLE IX
The procedure of Example VIII was followed except that the
polyethylene had a molecular weight of 3 .times. 10.sup.6. The
result was substantially the same as that in Example VIII.
The following examples are illustrative of the rigid gel
compositions of this invention containing a finely divided filler
material which minimizes dimensional instability.
EXAMPLE X
8.4 grams of a polyethylene having a molecular weight of 1.5
.times. 10.sup.6 to 2.5 .times. 10.sup.6, 8.4 grams of a nylon
powder, and 83.2 grams of Harmony oil (SAE No. 10 oil) were mixed
at room temperature. The mixture was poured into the annular space
of a ball bearing which was preheated to 350.degree.F. The filled
bearing was placed in a forced air oven at 350.degree.F. for 45
minutes. The bearing was cooled to 200.degree.F. The result was a
tough, oil-exuding, rigid gel in the bearing which did not hinder
the ball movement. There was no shrinkage of the rigid gel in the
bearing after 6 months.
EXAMPLE XI
8.4 grams of polyethylene having a molecular weight of 1.5 .times.
10.sup.6 to 2.5 .times. 10.sup.6, 8.4 grams of a nylon powder, and
83.2 grams of SAE No. 90 oil were mixed and heated at 380.degree.F.
until a rubbery gel was formed. The gel was cooled slowly until it
solidified. The product was a firm, rigid gel.
EXAMPLE XII
Two grams of polyethylene having a molecular weight of 3 .times.
10.sup.6, 75 grams of Security oil No. 53 (SAE No. 20 oil), 11
grams of a polyethylene having a molecular weight of 1.5 .times.
10.sup.6 to 2.5 .times. 10.sup.6 and 8 grams of a nylon powder were
mixed. The mixture was heated to about 350.degree.F. until a thick
gel was formed. The gel was cooled until solidified at about
200.degree.F. The gel was left set at room temperature for 6 months
and no dimensional changes were observed.
The next example is illustrative of another jelly-like gel
composition within the scope of this invention.
EXAMPLE XIII
Ninety-six grams of Sunoco No. 280 (SAE No. 20 oil) and 2 grams of
a polyethylene having an average molecular weight of 1.5 .times.
10.sup.6 to 2.5 .times. 10.sup.6 were mixed and slowly heated to
300.degree.F. At 300.degree.F., the mixing process was continued
for one hour. The hot mixture was then poured into a container and
cooled to room temperature. The result was a stable, oil-retaining
and rather smooth looking jelly-like product.
For the purposes of illustration, there is set forth below
compositions containing a low molecular weight polyethylene
component in addition to the high molecular weight polyethylene
component and lubricant component. It is noted that compositions of
this type can be prepared according to any of the methods discussed
above in connection with the two component composition, that is one
containing lubricant and high molecular weight polyethylene
components.
EXAMPLE XIV
Five quarts of SAE No. 20 oil containing 0.25 percent of a
polyethylene having a molecular weight of 23,000 and 0.25 percent
of a polyethylene having an average molecular weight of 1.5 .times.
10.sup.6 to 2.5 .times. 10.sup.6 was mixed and heated to
300.degree.F. to form a homogeneous low viscosity gel. Upon cooling
to 200.degree.F., the gel became more viscous and was a homogeneous
fluid gel. This product was used as a motor oil and placed into the
engine crank case of an old, worn-out 1957 Mercury automobile. The
combustion efficiency of the automobile increased 50 percent and
its oil consumption decreased by a factor of 10. When the product
was used as a motor oil additive in an automobile, the combustion
efficiency increased and its oil consumption decreased.
EXAMPLE XV
6.5 grams of a polyethylene having a molecular weight of 23,000 was
mixed with 91.5 grams of Gulf SAE No. 10 motor oil in a beaker and
heated to 180.degree.F. The viscosity of the mixture was about the
same as that of the oil. This mixture was then cooled to room
temperature and 2 grams of a polyethylene of an average molecular
weight of 1.5 .times. 10.sup.6 to 2.5 .times. 10.sup.6 was mixed
with it to form a dispersion of the polyethylenes and the oil. The
dispersion was then slowly heated and stirred in the beaker to
300.degree.F. After about 3 minutes a homogeneous mixture was
formed which was cooled to form a jelly-like, oil-retaining
homogeneous gel.
EXAMPLE XVI
91.5 grams of Gulf SAE No 10 regular motor oil, 6.5 grams of a
polyethylene having a molecular weight of 23,000 and 2.0 grams of a
polyethylene having an average molecular weight of 1.5 .times.
10.sup.6 to 2.5 .times. 10.sup.6 were thoroughly mixed. Sixty
lbs./hour of this mixture was passed through an extruder (1.5 inch
Thermatic extruder) having a screw diameter of 1.5 inches and a
barrel temperature of 270.degree.F. and a nozzle temperature of
350.degree.F. The product was similar to that of Example XV at room
temperature.
EXAMPLE XV
91.5 grams of Security No. 53 (SAE No. 20 oil), a pure hydrocarbon
oil containing no additives, 6.5 grams of a polyethylene having a
molecular weight of 23,000 2.0 grams of polyethylene having an
average molecular weight of 1.5 .times. 10.sup.6 to 2.5 .times.
10.sup.6 were thoroughly mixed and 20 lbs./hour of this mixture was
passed through a 1.5 inch Thermatic extruder with a barrel
temperature of 400.degree.F. and a nozzle temperature of
350.degree.F. The product was similar to that of Example XV at room
temperature.
EXAMPLE XVIII
Ninety-two grams of Sunoco No. 280 (SAE No. 20 oil), a petroleum
oil containing additives and inhibitors, 4 grams of a polyethylene
having a molecular weight of 23,000, and 4 grams of a polyethylene
having an average molecular weight of 1.5 .times. 10.sup.6 to 2.5
.times. 10.sup.6 were thoroughly mixed. Twenty lbs./hour of this
mixture was passed through the same extruder as in Example XVI. At
room temperature, the product was similar to that of Example XV,
except that it was more cohesive and stronger gel.
EXAMPLE XIX
The procedure of Example XVIII was followed except that the oil
used was Shell oil No. 66602, a bearing infusion oil. The product
was similar to that of Example XVIII.
EXAMPLE XX
94.50 grams of the petroleum oil used in Example XVIII, 2.75 grams
of a polyethylene having a molecular weight of 23,000, and 2.75
grams of a polyethylene having an average molecular weight of 1.5
.times. 10.sup.6 to 2.5 .times. 10.sup.6 were mixed and then passed
through a heat exchanger (Votator) at 17 - 19 p.s.i. and a
temperature of 300.degree.- 330.degree.F. The product was a thick,
cohesive liquid and upon cooling it became a homogeneous jelly-like
product. This jelly-like product was passed through an ordinary
meat grinder. The result was a smooth, grease-like gel.
EXAMPLE XXI
Ninety-six grams of the petroleum oil used in Example XVIII, 2.0
grams of a polyethylene having an average molecular weight of 1.5
.times. 10.sup.6 and 2.5 .times. 10.sup.6 and 2.0 grams of
polyethylene having a molecular weight of 23,000, were mixed and
slowly heated to 300.degree.F. At 300.degree.F. the mixing process
continued for one hour. The hot mixture was then poured into a
container and cooled to room temperature. The result was a stable,
oil-retaining, and rather smooth-looking jelly-like product.
EXAMPLE XXII
71.7 grams of Harmony oil No. 44 (SAE No. 10) and 0.7 grams of a
polyethylene having a molecular weight of 23,000 were thoroughly
mixed and heated until the polyethylene was dissolved in the oil.
The mixture was cooled to room temperature and 27.6 grams of
polyethylene having a molecular weight of 1.5 .times. 10.sup.6 to
2.5 .times. 10.sup.6 was added to and mixed thoroughly therewith.
The result was creamy, pourable and thick dispersion mixture.
A ball bearing was dipped into some SAE No. 40 oil and then placed
in a container and preheated for 15 minutes at 300.degree.F. in an
oven. The bearing was then removed from the oven and the space
between its inner and outer rings was filled with the dispersion
mixture which embodied the balls. The bearing was then returned to
the oven for 45 minutes at 300.degree.F. The bearing was cooled to
about 200.degree.F., the dispersion mixture solidified to a rigid
gel and the balls therein were completely free to rotate. The
bearing was self-lubricating and the rigid gel in the bearing was
oil-retaining.
EXAMPLE XXIII
Seventy-five grams of SAE No. 40 oil, 0.375 gram of a polyethylene
having a molecular weight of 23,000, 0.375 gram of a polyethylene
having a molecular weight of 1.5 .times. 10.sup.6 to 2.5 .times.
10.sup.6 and 8 grams of a dried nylon powder were mixed and heated
to 300.degree.F. while agitating the mixture. The heated mixture
was cooled to about 200.degree.F. and formed a fluid, weak gel
product. At room temperature, 12 grams of the 1.5 .times. 10.sup.6
to 2.5 .times. 10.sup.6 molecular weight polyethylene was added to
the fluid product and mixed thoroughly. This produced a dispersion
mixture of the product and the polyethylene. A ball bearing was
dipped into some SAE No. 40 oil and then placed in a container and
preheated for 15 minutes at 300.degree.F. in an oven. The bearing
was removed from the oven and the space between its inner and outer
rings was filled with the dispersion mixture which embodied the
balls. The bearing was returned to the oven for 45 minutes at
300.degree.F. After cooling to about 200.degree.F., the dispersion
mixture had solidified and the balls therein were completely free
to rotate. The bearing was self-lubricating and the solidified
mixture herein was oil-retaining. After 6 months there was no
shrinkage of the mixture in the bearing.
EXAMPLE XXIV
81.7 grams of Harmony oil No. 44 (SAE No. 10) and 1.5 grams of a
polyethylene having a molecular weight of 23,000 were mixed while
heating to 200.degree.F. The mixture was cooled to room
temperature. To this cooled mixture, 8.4 grams of a nylon powder,
and 8.4 grams of polyethylene having an average molecular weight of
1.5 .times. 10.sup.6 to 2.5 .times. 10.sup.6 were added and mixed
thoroughly and heated to 350.degree.F. for 15 minutes and then
cooled slowly to room temperature. The product was a tough, strong
solid. The product was left set for 6 months and the oil was still
well retained therein.
EXAMPLE XXV
Ninty-nine grams of Security oil No. 53 (SAE No. 20), 0.5 gram of a
polyethylene having a molecular weight of 1.5 .times. 10.sup.6 to
2.5 .times. 10.sup.6, and 0.5 gram of polyethylene having a
molecular weight of 23,000 were mixed and heated. Upon cooling, the
mixture formed a gel. There were mixed 75 grams of this gel with 12
grams of a polyethylene having a molecular weight of 1.5 .times.
10.sup.6 to 2.5 .times. 10.sup.6 and 13 grams of a nylon powder.
The mixture was poured into a mold and then heated at 325.degree.F.
for 30 minutes. Upon cooling, the product was a tough, rigid
gel.
EXAMPLE XXVI
Ninety-nine grams of Harmony oil No. 44 (SAE No. 10), 0.5 gram of a
polyethylene having a molecular weight of 1.5 .times. 10.sup.6 to
2.5 .times. 10.sup.6 and 0.5 gram of polyethylene having a
molecular weight of 23,000 were mixed and heated to 300.degree.F.
Of the heated mixture 77.8 grams were cooled to room temperature
and mixed with 13.4 grams of a the polyethylene having a molecular
weight of 1.5 .times. 10.sup.6 to 2.5 .times. 10.sup.6 and 8.8
grams of a nylon powder. A dispersion mixture was obtained which
was mixed thoroughly, poured into a mold and then heated to
300.degree.F. for 60 minutes. Upon cooling, a rigid, homogeneous
gel composition was produced in the shape of the mold which had no
shrinkage after 6 months.
* * * * *