Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Bismuth dithiocarbamates and their use as additive for lubricants
This invention relates to organic bismuth compounds and their use
as extreme pressure lubricant additives in oils and greases.
In some types of gears and particularly heavily loaded bearings
where both high pressure and high rubbing velocities are present, it
is difficult to maintain a thin film of lubricant between the gear or
bearing surfaces. When this thin film breaks, the mating metal
surfaces become susceptible to increased wear. This is particularly
marked in bearings where the mating metal surfaces can weld together.
When the weld shears under the relative motion of the surfaces,
particles of metal are removed which further damage the metal surfaces
of the gears and bearings and can seriously impairing performance.
In order to overcome such problems, special compounds have been
developed as extreme pressure (commonly referred to as EP) additives
for lubricant oils and greases. Thus, US 3139405 discloses the use of
antimony salts of dialkyldithiocarbamic acids as EP additives,
especially antimony dipentyl- and dihexyl- dithiocarbamates. This
patent states that these two compounds impart "amazingly high load-
bearing capacity" to lubricants and this is stated to be surprising
and unexpected since various other metallic salts of dialkyldithio-
carbamic acids tested alongside the antimony compounds impart only
moderate or low load bearing capacities to lubricants or are
ineffective e.g. by being insoluble. These other compounds include
two short chain linear alkyl, di-butyl and di-amyl (di-n-pentyl),
bismuth tris-dialkyldithiocarbamates. The antimony compounds
described in US 3139405 have been successfully used as EP additives
for many years and are commercially available e.g. under the trade
name Vanlube 73. However, none of the antimony dialkyldithio-
carbamates is ideal; some exhibit low solubility and/or poor stability
in typical lubricant systems and, furthermore, antimony salts are
toxic and can cause health and environmental problems.
In contrast to the teaching of US 3139405 we have now found that
certain bismuth salts of dialkyldithiocarbamic acids are useful as EP
additives for lubricants, such as oils and greases. Some of these
bismuth compounds give superior results as EP additives and/or better
WO 94i24100 '' ~ ~ 6 ~ 6 6 PCT/GB94/00830
-- 2 --
compatibility and/or stability in the lubricant as compared with their
antimony analogues.
Accordingly, the present invention provides a compound of the
formula (I~:
[ Rl.R2 - N - C(S) - S - ]3 Bi (I)
where
each Rl and R2 is, independently, Cl_l2 alkyl, C7_lz aralkyl
optionally substituted by Cl_l2 alkyl, cyclohexyl optionally
substituted by Cl_l2 alkyl; or
Rl and R2 together with the nitrogen atom to which they are
attached form a heterocyclic ring optionally substituted by Cl_l2
alkyl,
with the provlso that Rl and R2 sre not both ethyl, n-butyl or
n-pentyl.
Preferably, Rl is Cl_l2 alkyl, C7_l2 aralkyl optionally
substituted by Cl_l2 alkyl or cyclohexyl op~innnl1y substituted by
Cl_l2 alkyl; and R2 is C6_l2 alkyl, C7_l2 aralkyl optionally
substituted by Cl_l2 alkyl, cyclohe~yl opt~ nnn 1 ly substituted by Cl_lz
alkyl, isopropyl, isobutyl, tertiary butyl or branched pentyl.
- When Rl or R2 represents or includes alkyl, the alkyl group may be
linear or branched. Examples of alkyl are methyl, ethyl, isopropyl,
butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, l-methyl-
pentyl, 2-ethylbutyl, 2-ethylhexyl and l-methylhexyl.
When Rl or R2 is aralkyl it is preferably benzyl or phenylethyl,
optionally substituted in the phenyl ring by Cl_l2 alkyl. The phenyl
ring msy contain more than one alkyl group, but preferably carries one
alkyl group which is preferably present in the 4-position. An example
of an alkyl substituted aralkyl group is 4-methylbenzyl.
When Rl or R2 is alkyl substituted cyclohexyl, the cyclohexyl ring
may contain more than one alkyl substituent. However, when
substituted by alkyl, it is preferably a singly alkyl substituent,
which is preferably in the 4-position. Eramples of such substituted
cyclohexyl groups are 4-methylcyclohexyl, 4-propylcyclohexyl, 4-butyl-
cyclohexyl, 4-isopropylcyclohexyl, 4-tertiary butylcyclohexyl and
4-nonylcyclohexyl.
~ 0 94/24100 . PCTIGB94/00830
2I6066~
-- 3
When Rl and R2 together with the nitrogen atom to which they are
attached form a heterocyclic ring, the ring preferably contains 6
atoms as in morpholino, piperazino or piperidino. Where the ring is
piperazino, both nitrogen atoms may carry a dithiocarbamyl radical
whereby there is the possibility that the resulting bismuth salt is
polymeric. However, it is preferred that one of the nitrogen atoms of
the piperazino ring is substituted by Cl_l2 alkyl, especially Cl_g
alkyl and more especially Cl_4 alkyl.
When Rl or R2 is alkyl substituted aralkyl or cyclohexyl or Rl and
R2 together with the nitrogen atom to which they are attached form an
N-alkyl piperazino ring, the alkyl group is preferably Cl_8 alkyl, and
especially Cl_4 alkyl and may be linear or br~nrho~.
It is preferred that Rl and R2 are both linear or br~rhpd C1_l2
alkyl, and it i9 especially preferred that at least one of Rl and R2
is, or contains, branched alkyl since such compounds are easier to
formulate and dissolve in oils and greases than when.Rl and R2 are
both linear alkyl. Generally, we have obtained good results when Rl
or R2 and desirably Rl and R2 are not both linear short chain (Cl_s)
alkyl groups and this forms a particular aspect of the invention. Rl
and R2 can be mixed groups, particularly of groups of the same carbon
chain length e.g. mixed pentyl groups.
Although Rl and RZ may be different, they are preferably the same
because of the greater av~ bil~ty of symmetrical secondary amines
from which the dialkyldithiocarbamic acids are conveniently derivable.
In this context, 'symmetrical secondary amines' include amines made
with mixed alkyl groups, especially of the same chain length as in
secondary (mixed pentyl) amine.
The bismuth salts may be made from the single dialkyldithio-
carbamic acid or may be made from a mixture of such acids. When the
bismuth salt is made from a mixture of dialkyldithiocarbamic acids the
three dialkyldithiocarbamic acid radicals in formula (I) are not the
same. In certain circumstances it is beneficial to use a mixture of
acids since compatibility of the EP additive in a lubricant system
such as an oil or grease can be increased.
The dialkyldithiocarbamic acids can be made by methods known in
the art. However, since some dialkyldithiocarbamic acids are
-
WO 94/24100 6 69 PCTtGB94tO0830
-- 4 --
unstable, they are generally made as a salt which exhibits greater
stability. The salt may be formed with an amine or an alkali metal.
In one preferred method, the salt is formed with an amine and is
typically made by reacting an excess of a secondary amine of the
formula RlR2NH with carbon disulphide in an appropriate organic
solvent. The amount of amine used is preferably, 10 moles, more
preferably S moles and especially 2 moles per mole of carbon
disulphide. Such a method is described for example in Mém. services
Chim état, (Paris), 34, 411-12 (1948). Preferred solvents are inert
to the reactants and include ketones such as acetone. The reaction is
facile and is generally carried out at temperatures below 60C,
preferably below ZOC and especially below 10C. In another preferred
method, stoi~hi~ -tric amounts of the amine and carbon disulphide are
reacted together, and the dialkyldithiocarb~m;c acid then converted to
a salt, e.g. an alkali metal salt, by addition of a base, e.g. an
alkali metal hydroxide.
The bismuth salts of this invention are preferably made by
reacting the appropriate dialkylti~hioc~rbamic acid with a suitable
bil th halide such as bismuth trichloride in the presence of a
suitable organic reaction ~ lm. Generally, 1 mole of bismuth halide
i8 used with about three moles of the dithiocarbamic acid. The
organic reaction medium is desirably chosen to be a solvent for the
dialkyldithiocsrbamic acid and a non-solvent (or a poor solvent) for
the bismuth salt to ease separation of the bismuth salt from the
reaction mixture. However, if a volatile organic reaction ~ m is
used differential solubility of the bismuth salt is less important as
the solvent can be removed by evaporation and the bismuth salt
purified in conventional manner, for example, by recrystallisation.
Suitable solvents for the reaction of the bismuth trih~ e with the
dialkyldithiocarbamic acid are aliphatic hydrocarbons and chloro-
hydrocarbons and, especially, ketones such as acetone. The reaction
is typically carried out at temperatures below lZOC, preferably below
100C and especially below 60C. Where appropriate, the reaction may
be carried out in a solvent at reflux.
The bismuth salts of this invention are typically pale yellow
solids melting below 100C if derived from dialkyldithiocarbamic acids~
216066~9 PCrlGB94/00830
cont~;~i ng linear alkyl groups, but they can be oily liquids if
derived from a dialkyldithiocarbamic acid con~;ning branched alkyl
groups.
Particularly good EP properties in oils and greases have been
obtained with bismuth tris-[bis-(2-ethylhexyl)dithiocarbamate],
bismuth tris-(dihexyldithiocarbamate) and bismuth tris-[di(branched
pentyl)dithiocarbamate].
As described above, the bismuth salts of this invention exhibit
useful properties as EP additives in lubricating oils and gresses.
Some also exhibit useful antioxidant properties and superior stability
to the antimony analogues, especially against light.
Thus, in a further aspect, the invention provides a composition
comprising a bismuth salt of the formula I and a lubricant. The
lubricant is preferably an oil or a gresse.
In a further aspect, the invention provides a composition
comprising a grease and ce ,_ ~ of the formula (Ia):
[ Rl.R2 _ N - CtS) - S - ]3 Bi ~Ia)
where
each Rl and R2 is, indepPn~n~ly, Cl_lz alkyl, C7_12 aralkyl
optionally substituted by C1_12 alkyl, cyclohexyl optionally
substituted by C1_12 alkyl or
Rl and R2 together with the nitrogen atom to which they are
attached form a heterocyclic ring optionally substituted by C1_12
alkyl.
In a still further aspect, the invention provides a composition
comprising an oil and a compound of the formula (Ib):
[ R1.R2 - N - C(S) - S - ]3 Bi (Ib)
where
each Rl and R2 is, independently, Cl-12 alkyl, C7-12 aralkyl
optionally substituted by C1_12 alkyl, cyclohexyl optionally
substituted by C1_12 alkyl; or
Rl and R2 together with the nitrogen atom to which they are
WO 94/Z4l00 2~6~66 PCT/CB94/U083
attached form a heterocyclic ring optionally substituted by Cl_lz
alkyl,
with the proviso that when Rl and R2 are either both n-pentyl or
n-butyl the oil is not a SAE 90, high viscosity index, mineral oil
having a viscosity of 87 seconds Saybolt viscosity at 210F
(equivalent to about 17 cSt at 100C) and 1030 seconds Saybolt
viscosity at 100F (equivalent to about 190 cSt at 40C).
One preferred class of oils are gear or engines oils having a
viscosity above about 200 cSt at 40C, more preferably above 300 and
especially above 400 cSt at 40C. Such oils preferably have a
viscosity below 1500 cSt at 40C and especially below 1000 cSt at
40C.
Another preferred class of oils are lighter gear or engine oils
having a viscosity below 180, more preferably below 150 and especially
below 100 cSt at 40C. Such oils preferably have a viscosity above 10
and especially above 20 cSt at 40C.
The bismuth salt is typically used at a concentration of at least
0.01~, preferably at least 0.12, more preferably at least 0.5~, and
especially at least 2Z by weight, based on the total weight of the
lubricant. The bismuth salt may be present at a concentration up to
102, preferably up to 8Z, more preferably up to 6~ and especially up
to 52 by weight, based on the total weight of the lubricant.
The term oil includes oils such as those described in standard
texts on lubrication such as ~schmiermittel-Taschenhllch n by Schewe-
Kobak, (~uethig Verlang, Heidelburg, 1974) and in ~Schmierstoffe and
Verwandte Produkte~ by D Kl~ , (Verlage Chemie, Weinheim, 1982) and
also those described in US 3139405.
The oil is preferably a mineral oil or a synthetic oil or a
mixture of such oils. Examples of synthetic oils include polyalkylene
glycols; poly(alpha-olefins); esters, especially phthalates;
perfluoroalkylethers and silicones.
Preferred lubricants are industrial oils especially gear and
hydraulic oils.
The oil may contain other additives which are generally
incorporated in fluid lubricant, such as metal passivating agents,
viscosity index improvers, pour point depressants, dispersing agents.
~ O 94/21lOU ~ 66~
detergents, and other additives providing protection against wear,
extreme pressure, corrosion, rusting and oxidation.
The grease is preferably a mineral or synthetic oil as described
above which has been thickened by the addition of a gelling agent.
The gelling agents may be a soap, such as a lithium soap, a lithium
complex soap, a non-soap gelling agent such as a clay, a carbon black,
a silica or a polyurea which is preferably incorporated into the oil
in finely divided form. The clay is preferably surface coated with an
organic material to aid dispersion in the oil, such as a quaternary
r i compound. Where the grease is based on a silicone oil, the
non-soap gelling agent is preferably sillca, especially fused silica
having an average particle diameter below one ~m.
Metals which benefit from protection by the bismuth salt include
iron and copper and especially alloys such as steel and brass. As
disclosed above, bismuth salts of the fo_ l~e (I), (Ia) and (Ib) has
been found par~c-~lnrly effect as an EP additive in a lubricant where
the metals are in frictional contsct and form part of a gear or
bearing.
~ ccordingly in a further aspect, the invent$on provides the use of
a compound of one of the formula (I), (Ia) and (Ib) as an EP additive
for a lubricant, especially an oil or a grease.
In a yet further aspect, the invention provides a metal surface,
particularly a gear and especially a bearing which is treated with a
bismuth salt of one of the formula (I), (Ia) and (Ib) or a lubricant
composition cont~ning a bismuth salt of one of the formula (I), (Ia)
and (Ib).
The invention further includes a method of lubricating one or more
surfaces, especially of mating metal surfaces, which comprises
including in a lubricant, particularly a lubricating oil or grease,
for the one or more surfaces a bismuth salt of one of the formula (I),
(Ia) and (Ib), particularly in an amount of from O.l to lOZ by weight
of the lubricant.
WO 94/24100 2 1 6 ~ 6 ~ 9 PCT/GB94/00830 ~
-- 8 --
The invention is further illustrated in the following examples in
which all parts are by weight unless stated to the contrary.
Materials
BDAC bismuth tris-(di-n-pentyldithiocarbamate) made in Comparative
Synthesis Example C.
BDAC (mixed) is bismuth tris-~di-(mixed pentyl isomers)dithio-
carbamate] made in Synthesis Example 3.
BDHC is bismuth tris-(dihexyldithiocarbamate) made in synthesis
Esample 1
BDHC is bismuth tris-(dihexyldi~hioc~rbamate)
BDEHC is bismuth tris-[di-(2-ethylhexyl)dithiocarbamate]
ADHC is antimony tris-(dihexyldithiocarbamate) made in Comparative
Synthesis Example A.
ADAC is antimony tris-(dipentyldithiocarbamate) made in Comparative
Synthesis Example B
ADAC (mixed) is antimony tris-[di-(mixed pentyl isomers)
dithiocarbamate] made in Comparative Synthesis Example D
Vanlube 73 is a commercially avsilable nnt~ y tris-(dialkyldithio-
carbamate) EP additive from Vanderbilt C~ . ~, New York USA.
Synthesis Example 1
Bismuth tris-(dihexyldithiocarbamate)
a) dihexyldithiocarbamic acid dihexylamine salt
Carbon disulphide (13 g; 0.17 mol) dissolved in acetone (75 ml)
was slowly added over 20 minutes. with stirring to a solution of
dihexylamine ~63.02 g; 0.34 mol) in acetone (75 ml) keeping the
temperature below 5C. The acetone solution (193.8 g) was stirred for
a further 30 minutes and was used directly in the preparation of the
bismuth salt described below without isolation of ~he scid.
b) bismuth tris-(dihexyldithiocarbamate) (BDHC)
The solution of dihexyldithiocarbamic acid salt in acetone
(96.9 g) was stirred with anhydrous bismuth trichloride (7.89 g;
0 94/24100 ~6g PCT/GB94/00830
0.025 mol), and then heated to reflux at 56C for about 30 minutes.
The product separated as a yellow solid. Most of the acetone was
removed by distillation to leave the product as a yellow slurry.
Water (250 ml) was added and the solid filtered off, washed with water(200 ml) followed by methanol (100 ml). The product was finally
recrystallised from ethanol.
Yield: 20.76 g (74~ of theory); mp 79.8 - 80.4C.
Elemental analysis:- Theory 47.3~C; 7.9ZH; 4.22N, 19.4~S; 21.1ZBi
Found 47.32C; 7.9~H; 4.2~N; 18.8~S; Z0.5~Bi
Comparative Synthesis ExamPle A
Antimony tris-(dlhexyldithiocarbamate) tADHC)
The preparation of Synthesis Example l(b) was repeated, but
substituting ~nti y trichloride (5.63 g; 0.025 mol) for the bismuth
trichloride. The antimony salt was obtained as a pale yellow
crys~nlli n~ solid.
Yield: 15.84 g (622 theory); mp 69.6 - 71.2C.
Elemental analysis:- Theory 51.9ZC; 8.72H; 4.71N; 21.3ZS; 13.52Sb
Found 52.02C; 8.3ZH; 4.7~N; 20.4ZS; 13.5~Sb
Synthesis Example 2
Bismuth tris-[di-(mixed pentyl isomers) dithiocarbamate~ (BDAC mixed)
Synthesis Example 1 was repeated. but substituting dipentylamine
based on mixed pentyl isomers cont~;nin~ about 80~ branched pentyl
groups (53.5 g; 0.34 mol; from Aldrich Chemicals) for the
dihexylamine used in Synthesis Example 1. The bismuth tris-[di(mixed
pentyl isomers) dithiocarbamate] was obtained as yellow solution in
acetone. The product was recovered by distilling off the acetone and
washing with methanol (4 x 200 ml) to remove excess amine. The
methanol, which formed an upper layer, was decanted and the residual
oily product dissolved in methylene chloride. This was washed with a
waterlmethanol mixture (80:~0) (4 x 40 ml). The methylene chloride
WO 94/24100 ~ ~ PCT/GB94/00830
'6 ~ --
-- 10 --
solution was then dried over anhydrous sodium sulphate. screened and
the methylene chloride evaporated to give the title product as a
yellow oily liquid which slowly solidified on st~n~ing to yield a waxy
solid.
Yield: 12.5 g (55.3Z of theory).
Elemental analysis:- Theory 43.7ZC; 7.3~H; 4.6ZN; Zl.2ZS;
Found 43.6~C; 7.1X~; 4.5~N; 19.3ZS
Synthesis Exam~le 3
Bismuth tris-[di-(2-ethylhexyl)dithiocarbamate] (BDE~C)
Synthesis Example 2 was repeated, but substituting
di-2-ethylhexylamine (25 g; 0.34 mol) for the mixed isomer
dipentylPmine used in Synthesis Example 2. The bismuth tris-
(di-2-ethylhexyldithiocarbama~e) was obtained as a yellow solution in
acetone. The product was recovered by dis~ n~ off the acetone.
Methanol (200 ml) was added and the mi~ture cooled to 0C. The upper
solution was decanted off and the product washed further with methanol
(3 x 100 ml). A check of the decanted solution on the last wnshing
indicated the absence of further amine. The residual oily product
dissolved in methylene chloride, washed three times with water/
methanol mixture (80:20) (total volume 100 ml), dried over anhydrous
sodium sulphate, filtered and the methylene chloride evaporated to
give the title product as an orange oily liquid.
Yield: 20.2 g (70Z of theory).
Com~arative Synthesis Example B
Antimony tris-(di-n-pentyldithiocarbamate) (ADAC)
Di-n-pentyldithiocarbamic acid salt was prepared as described in
Example l(a), but substituting di-n-pentylamine (53.5 g; 0.34 mol;
from Aldrich Chemicals) for the dihexylamine.
The antimony salt was prepared by the method described in
comparative Example A, but substituting di-n-pentyldithiocarbamic acid
for the dihexyldithiocarbamic acid. The title product was obtained as
a pale yellow solid.
0 9412~100 ~ ~ 6 0 PCTIGB94/~0830
Yield: 13.7 g (67Z of theory); mp 70.2 - 71.0C.
Elemental Analysis:- Theory 48.4ZC; 8.lZH; 5.lZN; 23.5ZS; 14.9ZSb
Found 48.7ZC; 8.3ZH; 5.lZN; 23.1ZS; 14.4ZSb
Comparative Synthesis Example C
Bismuth tris-(di-n-pentyldithiocarbamate) (BDAC)
- The title compound was made by the method described in Example
l(a) and (b), but substituting di-n-pentylamine (53.5 g; 0.34 mol;
from Aldrich Chemicals) for the dihexylamine. The product was
obtained as a yellow solid.
Yield: 16.2 g (71Z of theory); mp 69 - 70C.
Elemental Analysis:- Theory 43.7ZC; 7.3ZH; 4.6ZN; 21.22S; 23.1ZBi
Found 44.ZZC; 7.5ZH; 4.6ZN: 21.3ZS; 22.7ZBi
Comparative Synthesis Example D
Antimony tris-ldi-(m$xed pentyl isomers) dithiocarbamate] (ADAC mixed)
Es~mple 3 was repeated, but substituting ant$mony trichloride for
bismuth trichloride as described in Comparative E~ample A. The
product was isolated as a yellow oily liquid.
Yield: 12.96 g (63.3Z of theory).
Elemental Analysis:- Theory 48.3ZC; 8.lZH; 5.lZN; 23.4ZS
Found 48.8ZC; 7.9ZH; 5.1ZN; 22.6ZS
APplication ExamPle 1
Various bismuth tris-(dithiocarbamates), and certain antimony
tris-(dithiocarbamates) as controls, were added to samples of a highly
refined neutral petroleum based base oil having a viscosity of
approximately lOOcSt at 40C to give an additive concentration of
0.0035 mol.(100 g oil)~l. These samples were subjected to a four ball
test according to British Institute of Petroleum test IP 239 and the
load at which welding occurred was measured. A control contn;n;ng no
WO 94124100 PCT/GB94100830
21~
EP additive was included. The sdditives, concentrations and welding
loads are set out in Table 1 below.
The results show that the bismuth tris-tdialkyldithiocarbamates)
are effective EP additives in the petroleum based oil.
APPlication Example 2
Various antimony and bismuth tris-(dithiocarbamates) were
evaluated as EP additives at a concentration of 0.0035 mol.(100 g
oil)~l as described in Application Example 1 and the loading
deter~inP~ at which welding occurred. The results show that the
bismuth tris-(dialkyldith~ocnrbamates) are effective EP additives in
the petroleum based oil. It i8 particularly notable that antimony
tris-(dipentyldithiocarbamate) made from linear dipentylamine (ADAC)
and from mixed isomers of dipentylamine (ADAC mixed) behave very
similarly as EP additives in the petroleum based oil. These antimony
salts behave very similarly as EP additives to Yanlube 73.
Remarkably, the bi th salts BDAC, BDAC (mised) and BDHC all eshibit
superior p ope-Lles as EP additives in the oil. th~s is contrary to
the tesrh~ngs of US 3139405 which demonstrates that both bismuth tris-
(dipentyldithiocarbamate) and bi_ th tri8-(dibutyldi~h;oc~rbamate) '
are significantly inferior to the antimony analogues.
-
AP~lication Example 3
Various antimony and bismuth tris-(dithiocarbamates) were
evaluated as EP additives in a lithium hydroxystearate soap thic~pnpd
grease. The base grease had a total soap content of 9.4Z by weight,
lithium 0.22Z and glycerol 0.6Z, which was dispersed in a refined
mineral oil derived from North West European crude having a specific
gravity of 0.88, a viscosity of 576 seconds Saybolt at 100F (about
120 cSt at 40C) and 67 seconds Saybolt at Z10F (about 12 cSt at
100C), a viscosity index of 95, closed flash point of 480F (250C)
and pour point of -15F (-26C). The compounds listed in Table 3
below were mixed into the grease, with heating as necessary, to
distribute the compound uniformly throughout the grease, to give a
concentration of 0.0035 mol.(100 g grease)~1. The results of four
ball testing as described in application Example 1 is included in
~ O 94i~4100 - 13 _ 60~ PcT/GB94~on83o
Table 3. These results indicate that the bismuth salts exhibit
similar performance in this grease to the antimony analogues. This is
unexpected from the teachings of US 3139405.
Applicstion Example 4
Application Example 1 was repeated using a lighter mineral oil,
Vitrea 22 (from Shell) having a viscosity of about 24 cSt at 40C.
The results are set out in Table 4 below. These show that the bismuth
salt exhibits a similar relative advantage over the antimony analogue
as established for the oil described in Application Example 1.
W O 94/24100~ ~ 6 ~ 6 ~ PCT/GB94/00830
- 14 -
Table 1
AdditiveconcentrationWeld load
(Zw/w) (kgf)
BDHC 3.42 S10
BDE~C 4.0 380
ADHC 3.12 310
ADAC 2.83 370
Control - 150
Table 2
AdditiveconcentrationWeld load
(~w/w) (kgf)
ADAC 2.83 3?0
ADAC (mixed) 2.83 370
Vanlube 736.40 330
BDAC 3.13 560
BDAC (mixed) 3.13 610
BD~C 3.42 S10
Control - 150
Table 3
AdditiveconcentrationWeld load
(~w/w) (kgf)
ADAC 2.83 330
ADAC (mixed) 2.83 350
Vanlube 73 6.4 340
BDAC 3.13 360
BDAC (mixed) 3.13 300
BDHC 3.42 380
Control - 130
Table 4
AdditiveconcentrationWeld load
(~w/w) (kgf)
ADAC mixed2.83 240
BDAC mixed3.13 370
