U.S. patent number RE31,611 [Application Number 06/258,448] was granted by the patent office on 1984-06-26 for lubricant compositions.
This patent grant is currently assigned to Rocol Limited. Invention is credited to Barry S. Charlston, Michael J. Green, Paul Wainwright.
United States Patent |
RE31,611 |
Wainwright , et al. |
June 26, 1984 |
Lubricant compositions
Abstract
A lubricant composition for use alone or in a lubricating base,
comprising a finely divided carbonate of Group IIA metal and a
halogenated organic lubricant.
Inventors: |
Wainwright; Paul (Chelmsford,
GB2), Green; Michael J. (Wetherby, GB2),
Charlston; Barry S. (Castleford, GB2) |
Assignee: |
Rocol Limited (Swillington,
GB2)
|
Family
ID: |
26250654 |
Appl.
No.: |
06/258,448 |
Filed: |
April 28, 1981 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
893609 |
Apr 4, 1978 |
04159252 |
Jun 26, 1979 |
|
|
Foreign Application Priority Data
|
|
|
|
|
Apr 6, 1977 [GB] |
|
|
14590/77 |
Jan 17, 1978 [JP] |
|
|
53-2843 |
|
Current U.S.
Class: |
508/168; 508/154;
508/180 |
Current CPC
Class: |
C10M
111/00 (20130101); C10M 141/00 (20130101); C10N
2010/04 (20130101); C10M 2201/061 (20130101); C10M
2201/103 (20130101); C10M 2201/084 (20130101); C10M
2201/18 (20130101); C10M 2213/062 (20130101); C10M
2201/066 (20130101); C10M 2211/022 (20130101); C10M
2201/08 (20130101); C10M 2213/02 (20130101); C10M
2201/081 (20130101); C10M 2201/082 (20130101); C10M
2209/107 (20130101); C10M 2211/08 (20130101); C10M
2201/16 (20130101); C10M 2211/06 (20130101); C10M
2201/00 (20130101); C10M 2201/062 (20130101); C10N
2050/10 (20130101); C10M 2201/10 (20130101) |
Current International
Class: |
C10M
141/00 (20060101); C10M 111/00 (20060101); C10M
001/10 (); C10M 003/02 (); C10M 005/02 (); C10M
007/02 () |
Field of
Search: |
;252/25,58 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
904232 |
|
Feb 1954 |
|
DE |
|
909618 |
|
Apr 1954 |
|
DE |
|
789562 |
|
Jan 1953 |
|
GB |
|
1100189 |
|
Jan 1964 |
|
GB |
|
960059 |
|
Oct 1964 |
|
GB |
|
Primary Examiner: Howard; Jacqueline V.
Attorney, Agent or Firm: Larson and Taylor
Claims
What we claim is:
1. A lubricant composition for use .[.alone or.]. in a lubricating
base, comprising a finely divided carbonate of a Group IIA metal
and a halogenated organic lubricant .Iadd., the carbonate being
present in a major proportion with respect to the halogenated
organic lubricant.Iaddend..
2. A composition according to claim 1, wherein the carbonate is
calcium carbonate.
3. A composition according to claim 1, further comprising a finely
divided inorganic sulphate salt.
4. A composition according to claim 3, wherein the sulphate is a
sulphate of a Group IA or IIA metal.
5. A composition according to claim 4, wherein the sulphate is
calcium sulphate hemihydrate.
6. A composition according to claim 1, wherein the halogenated
lubricant is a chlorinated paraffin.
7. A composition according to claim 1, further comprising
molybdenum disulphide.
8. A composition according to claim 1, wherein the carbonate is
present in an amount 5 to 15 times by weight of the halogenated
lubricant.
9. A composition according to claim 8, comprising a finely divided
inorganic sulphate salt in an amount by weight comparable to that
of the halogenated lubricant. .Iadd. 10. A lubricant comprising a
lubricant base and a lubricant composition comprising a finely
divided carbonate of a Group IIA metal and a halogenated organic
lubricant, the carbonate being present in a major proportion with
respect to the halogenated lubricant. .Iaddend. .Iadd. 11. A
composition according to claim 10, wherein the carbonate comprises
calcium carbonate. .Iaddend..Iadd. 12. A composition according to
claim 10 further comprising a finely divided inorganic sulphate
salt. .Iaddend..Iadd. 13. A composition according to claim 12,
wherein the sulphate comprises a sulphate of a Group IA or IIA
metal. .Iaddend..Iadd. 14. A composition according to claim 13,
wherein the sulphate comprises calcium sulphate hemihydrate.
.Iaddend..Iadd. 15. A composition according to claim 10, wherein
the halogenated lubricant comprises a chlorinated paraffin.
.Iaddend..Iadd. 16. A composition according to claim 10, further
comprising molybdenum disulphide. .Iaddend..Iadd. 17. A composition
according to claim 10, wherein the carbonate is present in an
amount 5 to 15 times by weight of the halogenated lubricant.
.Iaddend..Iadd. 18. A composition according to claim 17, further
comprising a finely divided inorganic sulphate salt in an amount by
weight comparable to that of the halogenated lubricant.
.Iaddend..Iadd. 19. A composition according to claim 10 wherein
said lubricant composition is present in said lubricant in an
amount of from 3 to 5% by weight. .Iaddend.
Description
The invention relates to lubricating compositions.
The use of solid lubricants e.g. graphite and molybdenum disulphide
as additives to greases and other lubricants, is well known.
Addition of solid fillers such as calcium carbonate to lubricating
greases in order to reduce the cost of the product composition has
also been practised to some extent for many years.
It has been widely accepted that molybdenum disulphide is
particularly effective under high loads and that it has the
property of reducing wear under these conditions. Recently however
rapid increases in the price of molybdenum disulphide have prompted
research into cheaper, but equally effective alternatives.
Surprisingly we have discovered that compositions containing in
combination a halogenated organic lubricant and a Group IIA metal
carbonate, optionally with molybdenum disulphide also, give
excellent results, comparable to or in some circumstances better
than those given by conventional molybdenum disulphide
compositions. The best results are obtained when an alkaline earth
metal sulphate or other inorganic sulphate is present also.
The compositions may be used alone or in lubricating bases,
particularly synthetic and mineral oil greases, in which the amount
of additives relative to the base may vary widely according to the
type of product and its intended use. There are for example
products on the market with 3% molybdenum disulphide and others
with 50%, and the compositions of the invention may substitute for
all of part of these amounts or be present in any other effective
amount compatible with the required physical properties of the
product. Generally, the final products may be pastes, greases, oils
or solid lubricating films; where the compositions are sold alone
they may be for use as lubricants in theemselves or use by
lubricant blending manufacturers.
The amount of weight of inorganic sulphate, where used, is
preferably comparable to that of the halogenated lubricant, with 5
to 15 times as much Group IIA carbonate by weight, as halogenated
lubricant.
Preferred halogenated lubricants are halogenated hydrocarbons,
particularly chlorinated paraffins.
Our most preferred materials are calcium carbonate (whiting) and
calcium sulphate hemihydrate, preferably in combination with the
chlorinated paraffins, but other materials are successful, for
example other carbonates; other sulphates such as magnesium
sulphate.7H.sub.2 O, calcium sulphate mono- and di-hydrates,
anhydrous sodium sulphate, potassium sulphate, potassium aluminium
sulphate, zinc sulphate, sodium hydrogen sulphate, and sodium
thiosulphate.5H.sub.2 O; and, among halogenated lubricants,
materials exemplified by `Cereclor` (Trade Mark) chlorinated long
chain paraffin hydrocarbons grades 70 (powder), 70 L, 63 L and 50
LV (I.C.I); similar bromoparaffins; fluorinated graphites of
formula (CF.sub.x).sub.n (Air Products); .[.`Monoflor` (Trade
Mark)53 and 91 fluorocarbons, which are liquids of formula (C.sub.2
F.sub.4).sub.n made by ionic polymerisation of tetrafluoroethylene
I.C.I);.]. `Fluon` (Trade Mark) L 169 polytetrafluoroethylene
(I.C.I); oligomer based fluorochemical waxes such as RDPE and
RDPE-S Wax (I.C.I.): .[.and low molecular weight
chlorotrifluoroethylene polymers of formula (CF.sub.2.CFCl).sub.n,
such as Halocarbon Products' Oil 14-25. .].
The inorganic materials are, as will be understood, in finely
divided form, for example the carbonate is suitably 99% less than
25 microns, 93% less than 10 microns.
The successful results of the invention are specific to the
combination of components, as is shown by the following results of
tests of various blends in white petroleum jelly as a lubricating
base. The tests were done in the well known `Seta-Shell` (Trade
Mark) four ball test machine, used for assessing lubricant
performance under extreme pressure. The smaller the scar diameter
found, the better the lubricant. The compositions are by weight,
the amounts of additives being relative to the composition as a
whole.
The first five blends are comparative, showing first the petroleum
jelly alone; then the effects of calcium sulphate hemihydrate,
`Cereclor` (Trade Mark) 63 L (a chlorinated paraffin containing 63%
chlorine), and `Snowcal` (Trade Mark) 8/SW whiting (calcium
carbonate) individually; and then the effect of the calcium
sulphate and calcium carbonate together. Blends 6 .[.to 9.]..Iadd.,
7, 9 and 10 .Iaddend.show compositons containing halogenated
lubricant and thus according to the invention, Blend 6 without
calcium sulphate and Blends 7 .[.to 9 with. Blend 8 .]..Iadd., 9
and 10 with. Blend 10 .Iaddend.further contains molybdenum
disulphide, and Blend 9 (an assembly paste) anatase TiO.sub.2,
primarily to give a good white appearance but also giving a very
high ultimate failure (weld) load.
Except at the lowest pressures Blend 7, with calcium sulphate, is
better than Blend 6, and both are better than even the best of the
comparative blends, particularly at the highest pressures, where a
scar diameter of over 2 mm indicates approaching failure.
Finally in Blends 8 and 11 there are shown for comparison the
effects of molybdenum disulphide (Blend 8) and `Lonza` (Trade Mark)
KS 2.5, a high quality artificial graphite (Blend 11). It will be
noted that the compositions of the invention are superior to both
these compositions throughout.
The results are as follows:
TABLE 1
__________________________________________________________________________
FOUR BALL TEST MACHINE RESULTS FOR VARIOUS LUBRICATING COMPOSITIONS
(SCAR DIAMETERS IN MM) APPLIED LOAD - KG BLEND COMPOSITION 56 100
158 200 251 316 355 398 447 501 562
__________________________________________________________________________
1. White petroleum jelly 1.58 2.59 Welds Blend at (Comparative) 141
kg 2. White petroleum jelly (a) 0.33 133 2.20 2.48 Weld Blend + (a)
2% (b) 20% -- 0.46 -- 1.24 -- 1.48 Weld (Comparative)
CaSO.sub.4.1/2H.sub.2 O (b) 3. White petroleum jelly 0.43 0.66 2.07
2.55 Welds Blend + 2% Cereclor 63L at (Comparative) 224 kg 4. White
petroleum jelly 0.43 0.66 0.86 0.96 1.45 1.66 1.76 1.78 1.96 2.15
2.27 Blend + 20% whiting (Comparative) (Snowcal 8/SW) 5. White
petroleum jelly 0.41 0.61 0.93 1.10 1.12 1.51 1.52 1.57 1.68 2.27
2.24 Blend + 20% whiting +2% (Comparative) CaSO.sub. 4.1/2H.sub.2 O
Blend 6. White petroleum jelly 0.33 0.39 0.72 0.90 0.97 1.06 1.36
1.53 166 1.79 1.84 + 20% whiting + 2% Cereclor 63L Blend 7. White
petroleum jelly 0.34 0.42 0.66 0.78 0.93 1.04 1.22 1.44 1.49 1.54
1.73 + 20% whiting + 2% (Welds Cereclor 63L + 2% at 708 kg)
CaSO.sub.4.1/2H.sub.2 O Blend 10. As Blend 7 + 20% MoS.sub.2 --
0.42 -- 0.60 -- 1.04 -- -- -- -- (Weld at 631 kg) Blend 9. As Blend
7 + 8% `Tions G` -- 0.39 -- 0.90 -- 1.28 -- -- -- -- (No weld
anatase TiO.sub.2 at 794 kg) Blend 8. Rocol ASP amber petroleum
0.35 0.42 0.96 1.14 1.43 1.47 1.44 Weld (Comparative) jelly + 50%
MoS.sub.2 Blend 11. White petroleum jelly + 0.36 0.46 0.71 1.23
2.00 Weld (Comparative) 50% graphite
__________________________________________________________________________
In addition to the results shown in Table 1 the mean Hertz loads (a
figure corrected for indentation of the balls and indicating wear
properties over a range of loads) of Blends 7, 10, 9, 8 and 11 were
determined at 104.7, 118.1, 99.9, 85.0 and 68.5 kg
respectively.
In further tests magnesium sulphate.7H.sub.2 O and anhydrous sodium
sulphate were substituted for the calcium sulphate sulphate.
1/2H.sub.2 O of Blend 7 above, .[.and `Monflor` 53 for the
`Cereclor`,.]. .Iadd.and `Monoflor` 53 for the
`Cereclor`,.Iaddend.with the results shown in Table 2.
TABLE 2 ______________________________________ Substituted Scar
diameter (mm) at load (kg.) Material 71 100 126 200 316
______________________________________ MgSO.sub.4.7H.sub.2 O 0.31
0.43 0.57 1.13 1.16 (Blend 12) Na.sub.2 SO.sub.4 0.33 0.45 0.48
1.05 1.09 (Blend 13) Monoflor 33 .Iadd.0.38 0.42 0.43 0.68 1.54
(Blend 14).Iaddend. .[.Monoflor 53 0.38 0.42 0.43 0.68 1.54 (Blend
14).]. ______________________________________
In the following, further results showing the merits of the
compositions of the invention are discussed, the `blends` referred
to being those of Table 1.
1. COMPARISON OF BLEND 7 WITH A KNOWN ANTI-SCUFFING PASTE
Test Method
The preferred composition in petroleum jelly (Blend 7) was compared
with Blend 8, which is known anti-scuffing paste as used in
engineering on an `Amsler` wear test machine. In this machine two
discs 2.5 inches (6.35 cm) diameter and 0.25 inches (6.35 mm) wide
are used. One disc, of phosphor bronze, is fixed whilst the other,
of hardened steel, can be rotated and loaded edge-on against the
stationary disc. Rotation of the steel disc under load produces a
wear scar on the bronze disc which can be accurately measured.
The technique used is to smear the two discs with the lubricant
blend. The steel disc is rotated at a fixed speed and then loaded
against the bronze disc, the test being continued for a given time
calculated from the peripheral speed of the steel disc, and chosen
to give a total of 250 feet (76.2 m) of sliding at the contact.
At the conclusion of each test the bronze disc is moved to give a
fresh contact position and the test repeated at a higher load. A
range of loads from 25 kg upwards in 25 kg steps up to 150 kg is
used and the sliding speeds are from 25 feet/minute (12 cm/sec) in
25 feet/minute (12 cm/sec) steps up to 125 feet/minute (60 cm/sec).
Each test is repeated to give a total of 3 tests for each
condition.
Results
The wear scar measurement results in inches (cm.times.0.394) are
plotted in FIG. 1, and also in FIGS. 4 and 5 as three dimensional
plots. The measurements, converted to volume of material worn away
in cubic inches (cm.sup.3 .times.0.06) and for clarity multiplied
by 10.sup.7, are plotted in FIG. 2. Finally the wear scar width and
applied loads have been used to calculate the final contact
pressure, plotted in FIG. 3.
Discussions of Results
In broad terms the blends show the same general characteristics in
that the amount of wear increases as the load increases, although
not in direct proportionality, and also in that for any given
applied load wear decreases as the speed is increased. (Care should
be taken that the wear versus speed characteristics are not wrongly
interpreted: the wear is for a given number of revolutions of the
disc and not a constant time. Thus the 25 ft/min (12 cm/sec) tests
ran for 10 minutes to produce the wear scar shown whereas the 125
ft/min (60 cm/sec) tests ran for 2 minutes only.)
Examination of the wear curve shape however shows important
differences between the blends. The curve slopes are quite
different. In terms of magnitude of wear Blend 8 is clearly better
at lower loads but the difference decreases as load increases and
the curves cross/over, so that the Blend 7 exhibits a lower wear at
higher loads. More significantly than actual wear scar width for a
given load is that increase in wear with increase in load shows
opposite characteristics for the two blends. With Blend 8 the
increase becomes progressively greater as load increases but with
Blend 7 the increase becomes progressively less.
Examination of the final contact pressure curves shows that Blend 8
gives a peak pressure at about 75 kg applied load--for all
speeds--and thereafter decreases, whilst the Blend 7 contact
pressure continues to rise. The full significance of this feature
is not properly understood; it may well be that this represents a
scuffing criterion or a change from `mild` to `severe` type of
wear. However it does illustrate the superiority of Blend 7 at
higher contact loads.
Conclusions
The above tests show that the preferred composition in petroleum
jelly (Blend 7) is effective as an anti-scuffing compound. In
particular the preferred composition is more effective than the
known Blend 8 at higher loads. This represents a significant
advance in current boundary lubricant technology, since molybdenum
disulphide is at present regarded as the most important solid
lubricant in commerce for boundary lubrication.
2. COMPARISON OF ANTI-SEIZURE PROPERTIES
Commercial anti-scuffing pastes such as Blend 8 are widely used as
anti-seize lubricants on fasteners subjected to high temperatures.
Comparison with the performance of Blend 7 under such conditions is
given below.
Test Method
Mild steel nuts and bolts are:
(i) degreased
(ii) treated with the blend.
(iii) tightened to a torque of 50 lb.ft (6.9 kg.m)
(iv) subjected to the test conditions.
(v) breakloose and prevailing torque are determined.
Results
(The torque figures quoted are in lb.ft (kg.m.times.0.138); BLT
stands for break loose torque.)
TABLE 3 ______________________________________ Test = 1 hour at
500.degree. C. using 5/8 inch (1.59 cm) UNF (Unifed Fine Standard)
mild steel nuts and bolts. BLT MEAN Prevailing torque
______________________________________ Blend 7 60 66 69 65 12 7 --
Blend 8 55 48 53 52 2 3 --
______________________________________
TABLE 4 ______________________________________ Test = 1 month (i.e.
31 days) outdoors using the same nuts and bolts. BLT MEAN
Prevailing torque ______________________________________ Blend 7 55
65 57 59 1 5 3 Blend 8 50 50 68 56 14 1 1
______________________________________
Conclusion
These results show the anti-seize properties of Blend 7 to be as
good as a known anti-seize lubricant containing molybdenum
disulphide.
3. PART REPLACEMENT OF MOLYBDENUM DISULPHIDE IN COMMERCIAL OPEN
GEAR GREASE
An important commercial use of molybdenum disulphide is to improve
the performance of open gear lubricants. Part replacement of
molybdenum disulphide by cheaper, but equally effective
alternatives, is of significant commercial importance.
Test Method
A number of grease blends were made up at different molybdenum
disulphide replacement levels. Table 5 below gives the composition
of each blend, by weight.
TABLE 5
__________________________________________________________________________
Parts by Weight Blend A (Comparative) Blend B Blend C Blend D
__________________________________________________________________________
Basic Grease `Baragel` clay thickener 6.0 6.0 6.0 6.0 `Dioxitol`
solvent 1.0 1.0 1.0 1.0 Water 0.1 0.1 0.1 0.1 `Pool 20` hydrocarbon
oil 83.9 83.9 83.9 83.9 Additives `TF` grade MoS.sub.2 9.0 6.0 3.0
-- `Cereclor 63L` chlorinated -- 0.15 0.30 0.45 paraffin
CaSO.sub.4.1/2H.sub.2 O -- 0.15 0.30 0.45 `Snowcal 8/SW` whiting --
1.53 3.06 4.59 100.0 98.83 97.66 96.49
__________________________________________________________________________
The volume of solids is the same in each formulation, i.e.
replacement is by volume, not weight.
Results
The load carrying properties of the greases were tested on the
Seta-Shell four ball test machine with the following results:
TABLE 6 ______________________________________ Blend Mean Hertz
Load Weld Load ______________________________________ A 64.5 282 B
86.5 316 C 89.6 398 D 88.0 355
______________________________________
Conclusion
The results show that the load carrying properties of the grease
are improved by the additives of the invention, and that they can
be used as a full or part replacement for molybdenum
disulphide.
4. DETAILS OF MATERIALS
The materials used above are further characterised as follows.
(a) `Cereclor` (Trade Mark) 63 L is a chlorinated paraffin,
manufactured by I.C.I. Ltd., and has the following properties:
______________________________________ Chorine content 63%
Molecular weight 430 Appearance Clear pale yellow liquid Colour 150
Hazen units Density at 25.degree. C. (77.degree. F.) 1.43 g/ml
Density at 99.degree. C. (210.degree. F.) 1.35 g/ml Viscosity at
25.degree. C. 150 poises Viscosity at 40.degree. C. 1000 cs
Viscosity at 100.degree. C. 18 cs Pour point (IP 15) approx.
0.degree. C. Normal free acidity at HCl 0.002% Normal free chlorine
0.0003% .[.-continued.]. Stability 4 hrs./175.degree. C. 0.02% HCl
released Flammability Non-flammable
______________________________________
(b) `Dioxitol` (Trade Mark) as supplied by Shell Chemicals Ltd.,
and is diethylene glycol monoethyl ether.
(c) Pool 20=`Gulfrex` (Trade Mark) 255 A mineral oil of the
following properties:
______________________________________ Specific gravity at
60.degree. F. 1.018 Redwood Viscosity at 70.degree. F. 2420 Redwood
Viscosity at 140.degree. F. 296 Flash point 500.degree. F. Pour
point 15.degree. F. ______________________________________
(d) `Snowcal` (Trade Mark) 8/SW
Ref. BWF 40; a general purpose finely ground filler classified by
water levigation. Its soft texture ensures easy incorporation into
rubber and plastic formulations.
______________________________________ Physical Properties
Percentage cumulative residue on BS Sieve No. 120 (125 microns)
trace 240 63 microns 0.02 350 45 microns 0.05 Percentage finer than
25 microns 99 20 microns 98 10 microns 93 5 microns 76 3 microns 54
Geometric Mean Diameter (microns) 2-3 Specific surface by air
permeability (cm.sup.2 g.sup.-1) 10.300 Hegman Gauge No. (North
Scale) 5.0 Hardness (Mohs) 2-3 Colour: CIE Tristimulus Y Value 87.0
Specific gravity 2.7 Bulk Density: Loose (lb ft.sup.-3) 36
Compacted (lb ft.sup.-3) 50 Loose (kg liter.sup.-1) 0.58 Compacted
(kg liter.sup.-1) 0.80 Void Volume (ml 100 g.sup.-1) 17.3 Chemical
Properties (%10) Calcium Carbonate (CaCO.sub.3) 98.0 Silica &
Insoluble (SiO.sub.2 & acid insoluble) 1.25 Alumina (Al.sub.2
O.sub.3) 0.25 Ferric Oxide (Fe.sub.2 O.sub.3) 0.08 Magnesia (MgO)
0.25 Sulphuric Anhydride (SO.sub.3) 0.04 Potash (K.sub.2 O) 0.01
Soda (Na.sub.2 O) 0.04 Matter Soluble in Cold Water 0.03 Moisture
(when packed) 0.1 Copper (Cu) 3 ppm Manganese (Mn) 240 ppm
Phosphorus Pentoxide (P.sub.2 O.sub.5) 1100 ppm pH of aquous
extract 8.5 Conductivity of aqueous extract (micro mho cm.sup.-1)
<100 ______________________________________
(e) `Baragel` (Trade Mark) is a conventional Montmorillonite clay
thickener.
(f) MoS.sub.2 (TF) is `technical fine` grade molybdenum disulphide
of particle size ca. 1.5 microns.
* * * * *