OSP=New Group
V Base Fluid for
Manufacture of
Sulfonate Greases
Govind Khemchandani, Ph. Di, Perry Byrd2, & Jeff St. Aubin3
1The Dow Chemical Company
Freeport, Texas 77541, USA
[email protected]
INTRODUCTION
Oil-soluble polyalkylene glycols
(OSPs), a new group V base fluid
derived from downstream derivatives
of butylene oxide (BO), have been
designed to provide good solubility
in API (American Petroleum
Institute) Groups Ito IV base oils
[1-4]. This new class of group V base
fluid now can be used as a co-base
oil in hydrocarbon base fluids, which
is not possible with conventional
polyalkylene glycols (PAGs). OSPs
have high viscosity indices (VI),
good low temperature properties,
low coefficients of friction and low
aniline points. OSPs help to improve
the deposit control of compositions
derived from mineral oil when used
as co-base oil. A combination of low
aniline point and deposit control
ability of OSPs were leveraged to
make lithium and lithium complex
greases [5-7].
Recent innovations in equipment
design have resulted in components
operating at higher speeds,
producing increased power output,
and as a direct result, operating at
higher continuous temperatures.
Under these severe conditions,
protecting equipment is stretching
the limits of conventional grease
technology [8]. These new tribo
machines create new opportunities
for grease formulators to use their
skills in developing products based
on new base fluids, thickeners and
superior additive systems. Without
change in base stocks or thickeners,
avenues for performance advances
become limited [9]. The quest for
better performing synthetic grease
prompted the authors to develop
‘over based calcium sulfonate
(OBCS)’ grease derived from OSP
base stock and super sulfonate
thickener.
OBJECTIVE
Conventional PAGs are used for
making greases with inorganic
and organic thickeners for specific
applications [10]. However, Calcium
Sulfonate Complex Grease is suitable
for a wide range of applications,
since it has various excellent inherent
properties in the sulfonate matrix
[11]. Basic technology for the
– 20 VOLUME 79, NUMBER 2
2MidSouth Sales, Inc
Jonesboro, Arkansas
‘Chemtool Incorporated
Rockton, IL
manufacture of Calcium Sulfonate
Complex Grease was established in
early 1980’s. Improvements in the
formulation and manufacturing
process have been made thereafter
and one can find several patents and
reports [12, 13]. However, Calcium
Sulfonate Grease was included in
‘NLGI Global Grease Survey’ as a
separate category [14] in year 2000.
Since then many excellent research
papers have appeared describing
their use in steel mills, automotive
and construction heavy equipment
[15].
In the components of grease, base
oil accounts for about 75-95 percent,
meaning that the performance of
grease is largely determined by the
characteristics of base oil. Therefore,
grease cannot be any better than
its base oil [16]. Consequently,
before selecting any base oil, its
characteristics should be examined
in detail for its desired application.
References 1 to 6 describe many
excellent characteristics of OSPs for
grease making. Further continued
research on OSPs has indicated novel
characteristics which are worth considering for choosing OSPs as base fluid for synthetic
grease formulations [17].
NLGI
NOVEL PROPERTIES of OSPs
Table 1 describes the physical properties of OSP base oils that can be used for Over based
Calcium Sulfonate (OBCS) Greases. Two important inherent characteristics of OSPs are:
1. improving hydrolytic stability of natural and synthetic esters
2. acting as a corrosion performance booster in ASTM D 665 B test
OS?1~
Grade
ASTM ASTh~
D445
1)445
A~M
UTM
ASTM
D217ê
D97
OSP-320
320
36
163
-37
230
<-30
OSP-460
460
52
177
-35
235
<-30
OSP-680
680
77
196
-30
243
640(>338)
ASTM D2266
040
4 SaIl Wear Test, mm Scar Diameter
,4-B~RWeldJ~9
Water Washout,~175° F(79~ Oj.% Loss
Timken OK load lbs
ASTM D2596
400
ASTMD 126401
ASTM D 2509
55
ASTMD 1743
Pass
ASTM U 942
I
ASTM D 5463
145
ASTM B117
500+ hours
ASTM D 5707
Pressure Vessel Oxidation
Psi pressure drop-ba hours
POSC,180~ C, Minutes
Sail Fo9Test
SRV:Fnction& Wear properties.
ScarDiameter,mm
Fi92
Coefficient of Friction
Fi93
~ 5706
Pass Load,N
Fi94
Base Oil Characteristics
Viscosity @40~ C cSt
ASTM D445
~çosity~ 100” ~,cSt
ASTM D445
Viscosity Index
ASTMD227O
,,,,,
,
,,
Figure 2: Wear Profile
of OSP based OBCS
Grease, ASTM D 5707
– 23 NLGI SPOKESMAN, MAY/JUNE 2015
0~5i1
0~125
:
334
44
189
NLGI
SRV~4 TEST SYSTEM
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~ No
~
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tW
11 Z4€~
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~
rk1~~1F
trrj
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-~
~
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~4
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~
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~_~1J
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2Afl
j~z
-~
–
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C
P22222
‘02
~
II
~
~
1~TF
r
TCI
-~
j
Reou
t~
I
T
I~.
I
12
ho ‘1
~11
I
F 2 2
4
i~3
~f o~
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Figure 3: Friction Profile of OSP-based OBCS Grease, ASTM D 5707
—
2’0F
00
2222
~3
202
20.~
J~1~0
~,
~,
10,
CCI~
1ç~2
o,cEl
1~Ad
~
221
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U
~
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x
p~-
jReouIts;r~i
~
~
1T~
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r~a~
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~
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Figure 4: EP Property OSP-based OBCS Grease, ASTM D 5706
– 24 VOLUME 79, NUMBER 2
°
~
RESULTS & DISCUSSION
The data on the OSP based OBCS grease showed
product with excellent EP/AW characteristics, extremely
high drop point, and very good oxidation stability
as indicated by PDSC and ASTM D 942 tests. It has
acceptable mechanical shear stability and excellent water
resistance capability as indicated by the water wash out
value of 0.7%. SRV test data show additional EP and low
wear properties of OSP based OBCS grease with low
coefficient of friction under chosen conditions of SRV
test High drop points greater than 300°C can be achieved
easily with the use of OSP.
In light of the results obtained from this work, we
can conclude that high performance OBCS grease
can be made with OSPs as base fluid using common
manufacturing methods for complex sulfonate greases
In earlier work [11] researchers made three complex
sulfonate greases using diester, polyol ester and PAG as
a base fluid They were unable to make stable grease and
found half the functional life of greases compai ed to
reference grease. OSPs now offer grease formulators an
option to make stable high performing synthetic grease
with OSP’s excellent inherent properties of improving
hydrolytic stability of esters and boosting corrosion
protection of PAGs.
CONCLUSIONS
• Formulators and researchers can now use Oil Soluble
Polyalkylene Glycols as primary base oil, a co-base oil
or as an additive in grease formulations
• OSPs can provide good friction control and higher
Oxidation Induction Time (OIT) values for greases
REFERENCES
1. Neil Canter, “New Type of Polyalkylene Glycol”,
Tribology and Lubrication Technology, October 2010,
pp 10-11
2. Govind Khemchandani, “Characteristics of New Oil
Soluble Polyalkylene Glycols”, STLE Houston Chapter,
February 9, 2011
3. Martin Greaves et al. “New Oil Soluble Polyalkylene
Glycols”, STLE, Las Vegas, May 19, 2010
4. Lisa Tocci, “Building a Better Base Fluid, Lubes N
Greases”, November 2013, pp.30-32
5. Govind Khemchandani, “New Oil Soluble
Polyalkylene Glycol for Making High Performance
Grease,” NLGI, Volume 76, Number 2, pp 36-41
6. Govind Khemchandani, “Characteristics of OSP
based Lithium Complex Grease,” NLGI, 80th Annual
Meeting, June 15-18, 2013, Tuscon, Arizona
7. E. Blancas-Sanchez, C. Galeano-Guerra, M.
Oyervides Muñiz, J. Chavez-Contreras, “Comparative
Analysis of OSP, Mineral, PAO and POE based
Lithium Complex Greases: A Rheological Approach”,
STLE, May 17-2 1, Orlando, 2014
8. John Lorimor, “Synthetic Greases Poised for Growth”,
Compoundings, Vol. 63 No.8, August 2013
9. Tim Sullivan, Averse to Change, Lubes N Grease,
Europe-Middle East-Africa, Aug 2012, pp 20-24
10. US Patent US 2011/0160110 Al, Lubricating Grease
Composition, June 30, 2011
11. Y. Kimura et al, “Study of Synthetic Oil based
Calcium Sulfonate Complex Greases”, NLGI 72nd
Annual Meeting, Oct3O-Novl, San Antonio, TX
12. Elidaes, T. I. “One Step Process for Preparation
of Over based Calcium Sulfonate Grease and
Thickened Compositions”, US Patent 4,597,880
(1996)
13. Olson, W D., Muir, R. J. et al. “Sulfonate Grease
Improvement” US Patent 5,338,467 (1994)
14 Jeff St Aubin, Calcium Sulfonate Greases NLGI
Advanced Grease Course, June 12, 2012, Palm
Beach, Florida
15 Lubricating Grease Guide, Chapter 4 pp 51 58 2006
Edition
16 Lou Robin et al, A Study of Composition and
Technology of Complex Lithium Grease, NLGI,
October 26 29, 1997
17. Martin Greaves, New Oil Soluble Polyalkylene
Glycols & Practical Aspect of Formulating Advanced
Lubricants”, Uniti Tech congress, Stuttgart, Germany,
Aprill9th, 2013
18. W. Mackwood, R. Muir, “Calcium Suffocate Grease
One Decade Later”, 65th NLGI Annual Meeting,
Naples, FL, October 25-28, 1998
19. Gareth Fish et al. “Calcium Sulfonate Grease
Revisited”, NLGI, 78th Annual Meeting, June 11-14,
2011, Desert Palm, California
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