Note: Descriptions are shown in the official language in which they were submitted.
3~
HIGH DRDPPING Por~r LITHIUM COMPLEX GRE~SE CQMPOSITION
me Eresent invention relates to a high-quality lithium-
~mrl~ grease c~mposition having a high dropping point, e~ n~.
oxidation stAbility, long lubxication life and very satisfactory
acoustic characteristic.
Lithium-soap greases are conventionally used widely for
their various merits, such as the fairly satisfactory thermal and
water resistance, easy dispersio.n in many types of lubricant base
materials c~nd the r~ n~hle prices. ~lowever, when this type of
grease is used at a temperature higher than 130C, -the lubricating
r~ rn~ "~,ln~e o the grease is rapidly lowered due to the micelle
destruction by oxidative deterioration, reduction of adhesivity,
softening and oil separation.
Whi.le rnn~ r-base greases of very high dropping points
and other various complex greases are developed for eliminating the
these thermal defec-ts, the thickeners of these greases can be
h~rde~1 or severely softened during their long use, and thus the
arrl;~ation of such greases is naturally limited also for their
high prices. On the other hand, the use envirorlment oE greases is
being rapidly agyLc~vclted with the advancing miniaturization of
.h;n~c and speeding up of working parts. For instance, when grease
is used in a place near the heat source of an engine, such as in a
bearing for el.ectr.ic ff~l; r ent~ the grease is exposed to a very high
t~mperature for a long time, and,
1~7Z3~
-- 2
therefore, has to be sufficiently durable to high tempera-
ture, long use and ambient moisture. Under such circumstance,
strong request.s are being made for the development of a
novel grease far more excellent in these characteristics
than the existent lithium-~oap. greases.
The purpose of the present invention is to answer
these requests by providing a high-quality lithium complex
.grease having a high dropping point, satisfactory adhesivity
and high thermal stability of the thickener micelles, all
of which are essential under the use condition higher than
130C, and this purpose can be achieved with a lithium
complex grease prepared by adm;~; ng and dispersing in a
base oil, a lithium salt of a fatty acid and/or hydroxy
fatty acid, that of aromatic hydroxyl carboxylic acid and
a succinimide-type dispersant and/or metallic-salt detergent,
as essential components.
It is disclosed in Canadian Patent 1,005,428, issued February
15, 1977, that a high dr~pping point lithium-soap grease caul be
prepared by ar~mi~; ng in a lithium soap of a hydroxy fatty
acid, a dilithium ~alt of an aliphatic dicarboxylic acid
or a monolithium borate and a lithium ~alt of a hydroxyl-
carboxylic acid, such as an aromatic hydroxy-carboxylic acid,
as essential cornponents. However, a grease of a sufficiently
high dropping point cannot be formed only from the two
2S components comprising a lithium salt of a hydroxy fatty
acid and a dilithium salt of an aromatic hydroxy carboxylic
acid.
':..
3~L
- 3 -
In the pre~ent invention, it ha~ been discovered that
an exceedingly high~quality and high-dropping point lithium
complex grease can be prepared by incorporating a ~uccinimide-
type dispersant and/or metallic-salt detergent, as a third
component, in addition to the two components mentioned above.
That is, the present invention provides a high-dropping-point
lithium-complex grea~e composition prepared by unlformly
a~ i ng an~ dispersing, in a base oil having a lubricating
viscosity, the following three essential component~ ;
(a) at least one lithium ~alt selected from the lithium salts
of ClO to C34 fatty acids and Cl2 to C24 hydroxy fatty
acids,
(b) a lithium ~alt of an aromatic hydroxycarboxylic acid, and
(c) a succinimide-type dispersant and/or metallic-salt
detergent.
In the following, a fur~her detailed descript~on i8 made
on the lithium~complex grease composition provid0d according
to the present invention.
Ba6e oil :
r~he base oil used in the composition accordlng to the
pre~ent inventlon i6 a mineral or synthetic hydrocarbon oil,
6ynthetic ester or similar oil or a mlxture thereof, which
are conventionally employed as lubricating oils. The vi6co~1ty
of thi6 base oil can be generally within the range from about
2 to 500 cSt at 40C, preferably from about 20 to 200 cSt at
L~OC.
:~ .
,~gt~
As the synthetic oil, use can be made, for example,
o~ a poly-~-olefine oligomer, such a6 an octene-l/decsne-1
copolymer having a viscosity of 41~0 cSt at 40C, V.I. of
130; pour point of -60C and flash point of 223C ; a
dicarboxylic acid ester, such as di-2-ethylhexyl sebacate ;
and a hindered-ester oil, such a6 caprylic ester of
trimethylolpropane and caproic ester of pentaerythritol.
Moreover, various other synthetic oils, such as polyglycol
oil, 6ilicone oil, polyphenylether oil, halogenated hydro-
carbon oil and alkylbenzene oil~ can also be used.
Component (a) :
The lithium soap to be admixed in the base oil accord-
ing to the present invention is selected from the lithium
salts of C10 to C34 fatty acids and those of C12 to C24
hydroxyfatty a.cids. The C10 to C34 fatty acids employed
for the formation o~ such lithium salts include saturated
or un~aturated higher ~atty acids, such as capric acld,
undecanoic acid, lauric acid, myristic acid, palmitic acid,
stearic acid, arachic acid, behenic acid, lignoceric a.cid,
2Q cerotic acid, montanic acid, melis6ic acid, aleic a.cid,
elaidic acid~ erucic acid, ~oomaric acid, gadoleic acid,
linolic acld and linolen~c acid, and the glycerides o~ these
acids. Among these acids and glycerides, those cont~ining
16 to 22 carbon atoms are preferable and especially ap-
propriate are palmiti.c acid, stearic acid and elaidic acid.
- ~97~33L
The C12 to C24 h~droxy fatty acids are normally those
straight-chained saturated or unsaturated aliphatic mono-
carboxylic acids containing a hydroxyl radical in their
respective molecules, for example, ricinolic acid, 2-hydroxy
dodecanoic acid, 2-hydroxy tetradecanoic acid, 2-hydroxy
hexadecanoic acid, ll-hydroxy hexadecanoic acid, ambrettolic
acid, ricinole~cacid, ricinostearolic acid, 9-hydroxy stearic
acid, lO-hydroxy stearic acid and 12-hydroxy stearic acid,
and, among these acids, those contein~ng 18 carbon atoms and
a hydroxyl radical connected to the 9-, lO- or 12-position,
especially 12-hydroxy stearic acid and ricinoleic acid are
preferable.
The lithium salts of the higher fatty acids above or
those of hydroxy fatty acids can be used singly or combinedly
with one or more of others. ~urthermore, when lithium salts
are prepared from these fatty acids or hydroxyfatty acids,
these acids can be reacted with lithium hydroxide, in the
~orm of their. free acids as well as of their glycerides.
Component (b) :
The second component to be admixed in the ba6e oil ac~-
cording to the present invention is a lithium salt of an
aromatic hydroxy carboxylic acid. The aromatic hydroxyl
carboxylic acid used should desirably be represented by the
formula,
o O OH
~}~
R
~ ~, 9 -7r,~
- 6 -
(wherein R denotes a hydrogen atom or hydroxyl, lower
alkyl or lower alkoxyl radical),
and there are included in this category those acids such as
p hydroxy benzoic acid, salicylic acid ~o-hydroxy benzoic
acid), 2-hydroxy-4-hexyl benzoic acid, m-hydroxy benzoic
acid, 2,5-dihydroxyl benzoic acid (gentisic acid), 2,6-
dihydroxyl benzoic acid ( r-resorcylic acid) and 4-hydroxy-
3-methoxy benzoic acid. Salicylic acid is especially
preferable among them. Incidentally, the hydroxyl radical
(OH) in sald lithium salt can be present in its ~ree kype
as well as in the form of -OLi.
Component (c) :
The third component to be compounded in.the base oil
according to the present invention is employed for accelerat~
ing the fine dispersion of the components (a) and (b) in
the base oil, and a succinimide-type disper~ant and metallic-
s~lt detergent are used respectively singly or combinedly
with one or more of others.
2Q The succinimide-type dispersant usable a~ Component (c)
in the present inventi.on can be those ones synthesized by
the reaction of polyamine and polybutenyl succinic anhydride
(obtained by the reaction of polybutene and maleic anhydride)
among the additives effeckively dispersing engine-oil sludge
in the engine oil, and there are included in khis category
the compounds represented respectively by the following
~ormulae,
-- 7
A -CH~
N~ -C~l ~N~ H (I)
CH2 C ~ 2 2 p
Al CH C~ ,~C-CH-A
~ ~C~2-~ ~2-N~ CE~2~ H? `C-CH2
c~2-c~
t II)
Ai-CH-C~ ~"-CH-A
CB -C ~ 2~ H2 lI2 1~}~; CH2cH2 N~C C~
O' `O
HO ` O ' CH
( III)
Al_C~_C.~ ~C~ -C~
N-C~2-CH2-N '` NH
~C~2-C~ , CH2 CH2
(IV)
l O
A -CH-C ~;
C~l -C ~ ~ ~2 C~2 N~;
i~ "O 0~
o~ b
B
HO' ~0' ~ 0~1
'(V)
Al-C~i-C ~ CH
CH -C ~ H2 CH2 N~ CH2-CH2-N ~ 3
(Vl)
~L~9~;~3~
-- 8 --
(wherein Al denotes a C~O to C200 polyisobutenyl rad~cal,
p mean6 an integer from 2 to 8 and q repre6ents an
integer from l to 8)
The metallic salt detergent usable as Component (c)
means those organometallic compounds capable of preventing
or suppressing the deposition of the deteriorated matter in
an engine to keep the engine interior clean, and includes
those sulphonates, phenates, phosphonates and salicylates
represented respectively by the formulae shown below.
(i) Sulphonate.
I'' ' "
A~ A2
( ~r - ~o3 ~ ~Ar - ~a~
,~,2.t ~ ~,2~
(wherein A2 and A2 denote respectively a hydrogen atom
or C8 to C30 alkyl radical, Ar means a benzene rlng or
naphthalene ring, M represents an alkaline earth metal,
such as Ca, Ba or Mg, and M denote6 an ~lk~li metal,
such as Na, K or Li)
(ii) Phenate.
O~ O
' l 1
A~ ~ ~s ~
(wherein A3 denotes a C4 to Cl6 alkyl radical, M means
an ~lk~line earth metal, such as Ca, Ba or Mg, and x
denotes an integer, l or 2)
~7~3~
g
(iii) Pho~phonate.
O O
Il 11
A~ - P - O - ~ ~ - P - 8 -
L oJ ~ L oJ
o o
Il 11
_ p _ o ~ ~ A 4 --P ~ B --P
L o J , L ,~ ~
(wherein A4 means a C30 to C200 polyisobutenyl radical
and M denotes an alk~ e earth metal, such as Ca, Ba
or Mg)
(iv) Salicylate.
0
( A~ ~ Coo
(wherein A5 denotes a C8 to C2~ alkyl radical and M
means an ~lk~11ne earth metal, such a~ Ca, Ba or Mg)
Among these metallic-salt detergents9 calcium ~ulphonate,
calcium phenate, calcium salicylate and magnesium salicylate
lQ are particularly preferable.
Preparation of grease composition :
The grease composition of the present invention can be
prepared by uniformly a~ ing and finely dispersing the three
components, (a), (b) and (c), in the base oil mentioned above.
The ~m; ~i ng proportions of these three components are not
3~1
- 10 -
necessarily precise but can be variable according to the
types of individual components1 and it is generally advan-
tageous to compound these components in the following
proportions per lO0 weight parts of the base oil ;
Component(a) - 2 to 40 weight parts, preferably 5 to 20
~eight parts,
Component(b) - 0.05 to 20 weight parts, preferably 0.1 to
20 weight parts,
Component(c) - 0.01 to 10 weight parts, preferably 0.1 to
5 weight parts.
Furthermore, the component~ (a) and (b) should desirably
be used in the following mol ratio within the respective
ranges of the proportions specified above ;
Component(a)/Component(b) mol ratio = 005 to l.0, preferably
l to 5.
The composition according to the present invention can
al~o be prepared from the above three component~ (a), (b) and
(c) together with those optional lubricant additives con
ventionally ~mployed, such a8 an oxidation inhibitor (e.g.
2,6-ditertiarybutyl-4-methyl-phenol, N-phenyl- d naphthyl-
amine and diphenylamine octylate), rust inhibitor (e.g.
oxygenated para~fin, amino-imidazoline and barium dinonyl-
naphthalene-sulphonate) and extrem-pressure additive (e.g.
zinc naphthenate, lead naphthenate, sulphurized oils and
fats, and tricresyl phosphate). In the following, a de-
scription is made on a general process for the preparation
'7~3~
-- 11 --
of the grea~e composition accvrding to the pre~ent
invention.
Firstly, a component (c) i~ di6solved in the base
oil at 70 to 80C, followed by the fatty acid or hydroxyl
fatty acid for the formation of a component (a3. Then,
the lithium hydroxide in a roughly equivalent amount to
said fatty or hydroxyfatty acid i8 admlxed in the mlxture
at 80 to 90C to form a soap. After the resulting solution
is somewhat cooled, the aromatic hydroxyl carboxylic acid
for the formation of a component (b) is admixed in the
solution at 70 to 80C, the resulting mixture is gradually
heated again to 80 to 90C and the lithium hydroxyde in an
amount roughly equivalent to that of the aromatic hydroxy-
carboxylic acid above is admixed in the mixture. The final
mixture is further heated to 145 to 150C under pressure
~or dehydration. A~ter the dehydration, the mixture is
again heated up to 195 to 220C, then cooled to 175 to
193C, kept at this temperature ~or 10 to 40 min and finally
cooled to the room temperature for the completion of the
preparation.
The lithium-complex greas~ compo6ition thus provided
by the present invention has an exceedingly high dropping
point and satisfactory acoustic ch~racteristic together with
a long lubrication li~e, as a high-per~ormance grease, and
can be suitably used for the lubrication of the bearing6
for electric motors and of the wheel bearings for automotive
compact axle boxesO In addition, because of the excellent
~ y ~-,3~
\
- 12 -
acoustic characteristic, the present grease compo~ition can
be satisfactorily used in the bearings of` air-conditioners
etc, making little noise and confortable surroundings.
The present invention is further concretely illustrated
by mean~ of examples as follows~
Example 1
23521.2 g o~ a refined mineral oil (paraffinic~ VI : 102,
pour point : -15C, kinO viscosity : 44.9 cSt at 37~8C~
6.4 cSt at 98.9C~ 9 30 g of a succinimide (A) (ref. Note 1)
and 270 g of 12-hydroxy stearic acid were introduced into a
5 liter autoclave and the contents were heated to 80C under
stirring in 30 to 40 min to completely di~solve the hydroxy-
stearic acid. (Note 1) Succinimide (A)
Al CH C" ~` C-CU-A
CH -N}3~ CH -C~2-N
CH-;~ C-CH2
` O OH O~'
O' `O
~ B
~ O ~ ~
~Al : C52 to C76 polyisobutenyl radical, mean molecular
weight : 2,302 (as contalnlng boron), 110 wt~ parts of
the compound above dissolved ln 100 wt. parts of the base
oil~
Sub~equently, 300 g o~ a hot aqueou~ solution (95C)
cont~l ni ng 38.5 g of lithium hydroxide were admixed in the
autoclave contents, which were then kept at 90C under stirring
~723
-- 13 --
for 5 to 15 min. After the contents were cooled to 75QCf
300 g of a hot aqueous solution (93C) contairling 49.8 g
of salicylic acid were admixed in the contents and dissolved
by stirring for 10 to 15 min. Then, 250 g of a hot aqueous
solution .(95C) containing 31.0 of lithium hydroxide were
admixed in the resulting mixture, which wa~ then gradually
heated under stirring and pressure. When this mixture
arrived at 145 to 150C after 1 to 1.5 hrs, the autoclave
was released of the pressure and the contents were dehydrated
at this temperature in 15 to 25 min, After the dehydration,
the contents of the autoclave were further heated to 195 to
205C, then cooled to 188 to 192C under stirring.and, after
being kept at thie temperature for 20 to 30 min, further
cooled to about 160Co At:this temperature; 60 6 of an
oxidation inhibitor were admixed in the contents, the mixture
thus obtained was cooled by stirring to about 80 to 85C in
30 to 60 min and then treated in a homogenizer. at this
temperature.
The properties of the grea6e composition thu~ prepared
were as follows ;
Consistency 1 (unworked) : 239
" (after 60 strokes) : 236
Shell roll test 2 (100C x 5 hrs)
(before test) : 119
(a~ter test) : 149
(difference) : ~30
~3L9~7~3
-- 14
Dropping point 1 (C) : 280
Oil separation 1 (100C x 24 hr~ 2.2 %
Waker resistarlce 1 (3&~C x 1 hr) : 2.0 %
Copper-plate corrosion 1 (100C x 24 hrs) : pass
Grease d~st-noise test 3 (after 120 sec3 : 68 (mean of 5
measurements)
Functional life 4 : 2540 hrs
( Note
*1 : according to JIS K2220,
~2 : roll stability test according to ASTM D1831,
*3 : according to the method described in Japanese Patent
Publication No. 2357/78, published January 27, 1978.
*4 : according to ASTM D1741
Comparison Example 1
A grease composition was prepared in a similar manner
to that in Example 1 except that 2,531.2 g of the re~ined
mineral oil were employed without the.succinimlde(~) being
admixed. The properties of the resulting comp~sition were
as follows ;
Consistency (unworked) : 278
(after 60 strokes) : 266
Shell roll test (100C x 5 hrs)
(before test) : 139
(after test) : 173
(difference) : +34
7~
- 15 -
Dropping point (C) : 195
Grease dust noise test (after 120 sec) : 4,11~ (mean of 5
measurements )
Functional life : 1,240 hrs
Examples 2 to 8, Comparison Examples 2 and 3
Seven grease compositions were prepared by treating the
various components shown in Table 1 below in similar ways to
that in Example 1 and the properties thereof are collectively
tabularized in Table 1. Also, the properties of a market
grease comprising the lithium soap of 12-hydroxystearic acid
are shown as Comparison Example 2 in the table as well, In
addition, Comparison Example 3 in the table is a grease
prepared in a similar manner to that in Example 1 but by
employing an increased amount of the refined mineral oil
15 : without the components (b) and (c) being admixed.
- 16 --
Table 1
~ Compo6ition/Example Composition (~eight %)
Component/Property ~ 2 3 4 _ 5 6 7 8 c_zc ~ C-3
~) 12-hydroxy stearic acid 9.0 9.0 9.0 9.0 9.0 9 o 9 o 9 0
(b) Salicylic acid 1.66 1.66 1.66 1.66 1.66 1.66 1.66 Market
(c) Succinimide (B),(l) 1.0 grease
Succinimide (C),(2) 1.0
Succinimide (D),(3) 1.0
Celcium fiUl phonate, ~4) 1.O
~5agnesium salicylate, (5) 1.0 .5
Czlcium 6slicylate, (6) . _ 1 .0
Lithium bydroxyde monohydrate 2.30 2.30 Z.30 2.30 2.30 Z.30 2.30 1.29
Oxidation inhibitor, (7) 2.0 2.0 2.0 2.0 2.0 2.0 Z.O 2.0
Base oil (refined mineral oil),(c) o4.04 84.04 84.04 84.04 84.04 84.04 o4.04 87.71
Properties :
Consi~tency (un~orked) 221 218 255 242 229 258 241 272 234
" (after 60 stroke6) 222 214 248 240 226 251 239 273 232
Shell roll te6t,~(before te6t) 110 lOo 128 121 114 130 121 137 117
(100C x 5 hrs) (after te6t) 138 129 157 154 151 163 160 168 165
difference) l28 +21 +29 +33 ~37 +33 +39 +31 '48
Dropping ooint (C)~280 >280 >280~280 ~Z80 ~260 ~280 180 200
Grease dust-noi6e test
(sf~er 120 6ec) 48 102 80 66 121 65 93 5 140
Eunctional life (hr) 3020 18602540 _ 2660 1780 2480 2800 500 480
g7;~3~L
-- 17 --
(Note for l'able 1)
CH~ ' `'C-CB-A
2- CE2-b~3 C~2 CH2 ~ C-CH2
L~l C52 to C76 polyisobutenyl radical,
Mean molecular weight : 2,17~
110 weight parts of the above compound dissolved in 100
wei~ht parts of a refined mineral oil.
(2)
-CH-C ~
CH~C ~ ~CH2 CE~2 N~ CH2-CH~'-NH2
~0
l : C52 to C76 polyisobutenyl radical,
Mean molecular weight : 1,172~
160 weight parts of the compound above dissolved in 100
weight parts of a refined mineral oil.
~3)
Al-C~-C"
c~-c~ 2 ~2 M~3C~2-C~2-N~
~O 0
B
O' `o
B B
~6 0~ _r~ ~
LA1 C52 to C76 polyisobutenyl radical,
Mean molecular weight : 1304~
140 weight parts of the compound above dissolved in lOG
weight part~ of a refined mineral oil.
~A.
723
-- 1 8 ~
(4) Calcium dinonylnaphthalene-sulphate
.. _ . . . ... . .. .
~C~ ~ ) 2C a
0 ~,
39 weight part~ of the compound above dissolved in 100
weight parts of a refined mineral oil.
(5) Magnesium alkyl-salicylate
. . . . .. .. .. . . .
~ ~ O EI J ~ ,
IR C10 to C16 alkyl radica~
30 weight parts of the compound above d1s olved i~ 100
weight parts of a refined mineral oil.
(6) Calcium alkyl-sa.licylate
0
~R C10 to C16 alkyl radica~
lQ 30 weight parts of the compound dis~olved in 100 weight
part~ of a refined mineral oil.
(7) rr'he same as that u~ed in Example 1.;
(8) r~he same as that used in Example 1.
