U.S. patent application number 10/554653 was filed with the patent office on 2007-04-19 for lubricant compositions.
Invention is credited to William David Phillips.
Application Number | 20070087944 10/554653 |
Document ID | / |
Family ID | 33397008 |
Filed Date | 2007-04-19 |
United States Patent
Application |
20070087944 |
Kind Code |
A1 |
Phillips; William David |
April 19, 2007 |
Lubricant compositions
Abstract
A lubricant composition for a high load carrying oil comprises a
synergistic mixture of a neutral alkyl phosphorus compound and a
sulphur carrier. The neutral alkyl phosphorus compound is selected
from neutral alkyl and alkoxyalkyl phosphates, phosphonates,
phosphinates and phosphites. Preferred neutral alkyl phosphorus
compounds are triisobutyl phosphate, tributoxyethyl phosphate and
dioctyl octyl phosphonate. Preferred sulphur carriers are
sulphurised fatty acid esters and dialkyl polysulphides. High load
carrying oils containing the lubricant composition of the invention
include metal working fluids, gear oils, extreme pressure turbine
oils and hydraulic oils.
Inventors: |
Phillips; William David;
(Cheshire, GB) |
Correspondence
Address: |
Michael P Dilworth;Chemtura Corporation
199 Benson Road
Middlebury
CT
06749
US
|
Family ID: |
33397008 |
Appl. No.: |
10/554653 |
Filed: |
April 23, 2004 |
PCT Filed: |
April 23, 2004 |
PCT NO: |
PCT/GB04/01750 |
371 Date: |
October 26, 2005 |
Current U.S.
Class: |
508/433 |
Current CPC
Class: |
C10M 141/10 20130101;
C10N 2040/247 20200501; C10M 2223/04 20130101; C10N 2040/12
20130101; C10N 2040/22 20130101; C10M 2215/042 20130101; C10M
2203/1025 20130101; C10M 2223/049 20130101; C10M 2219/024 20130101;
C10M 2225/04 20130101; C10N 2040/20 20130101; C10M 2219/022
20130101; C10M 2225/00 20130101; C10N 2040/04 20130101; C10N
2030/06 20130101; C10N 2040/08 20130101; C10M 169/04 20130101; C10M
2223/047 20130101; C10M 2223/06 20130101; C10M 2219/044 20130101;
C10M 2223/045 20130101; C10M 2203/1065 20130101; C10M 2221/041
20130101; C10M 173/00 20130101 |
Class at
Publication: |
508/433 |
International
Class: |
C10M 137/10 20060101
C10M137/10; C10M 169/04 20060101 C10M169/04 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 28, 2003 |
GB |
0309571.8 |
Claims
1. A lubricant composition for a high load carrying oil, said
lubricant composition comprising: (a) a neutral alkyl phosphorus
compound selected from the group consisting of (i) a neutral alkyl
phosphate of the general formula I ##STR14## wherein R.sub.1,
R.sub.2 and R.sub.3 are the same or different and are alkyl groups
of 1 to 18 carbon atoms; (ii) a neutral alkoxyalkyl phosphate of
the general formula IV ##STR15## wherein R.sub.4, R.sub.6 and
R.sub.8 are --C.sub.2H.sub.4 or C.sub.3H.sub.8 and R.sub.5, R.sub.7
and R.sub.9 are the same or different and are alkyl groups of 1 to
8 carbon atoms and n is 1 to 6; and (iii) a neutral
dialkylalkoxyalkyl phosphate of the general formula XI ##STR16##
wherein R.sub.2 and R.sub.3 are the same as in formula I above and
R.sub.4 and R.sub.5 are the same as in formula IV above and
mixtures thereof; and (b) a sulphur carrier containing active or
inactive sulphur and which is selected from the group consisting of
sulphurised synthetic esters, sulphurised vegetable oils and fats,
metal sulphonates, dialkylpolysulphides and mixtures thereof.
2. The lubricant composition according to claim 1 wherein the
neutral alkyl phosphorus compound and the sulphur carrier are
present in a weight ratio of P to S content from 1:50 to 1:1.
3. The lubricant composition according to claim 2 wherein the
neutral alkyl phosphorus compound and the sulphur carrier are
present in a weight ratio of P to S content from 1:1 to 1:30.
4. The lubricant composition according to claim 1 wherein the
phosphorus compound is selected from the group consisting of
triisobutyl phosphate, tri-n-butyl phosphate, triisopropyl
phosphate, triocyl phosphate, tri-2-ethylhexyl phosphate,
tributoxyethyl phosphate, butoxyethyldioctyl phosphate and mixtures
thereof.
5. The lubricant composition according to claim 1 wherein the
sulphur carrier is selected from the group consisting of a
sulphurised fatty acid, a dialkylpentasulphide and mixtures
thereof.
6. (Canceled)
7. The lubricant composition according to claim 1 which is a metal
working fluid, a gear oil, an extreme pressure turbine oil or a
hydraulic oil.
8. (Canceled)
9. The lubricant composition according to claim 1 wherein the
phosphorus compound is selected from the group consisting of
triisobutyl phosphate, tri-n-butyl phosphate, triisopropyl
phosphate, triocyl phosphate, tri-2-ethylhexyl phosphate,
tributoxyethyl phosphate, butoxyethyldioctyl phosphate and mixtures
thereof and the sulphur carrier is selected from the group
consisting of a sulphurised fatty acid, a dialkylpentasulphide and
mixtures thereof.
10. The lubricant composition according to claim 1 further
comprising one or more additional components selected from the
group consisting of surfactants, non-ionic alcohols and mixtures
thereof.
11. A method for working metal comprising (a) contacting a metal
workpiece with a metal working fluid comprising an effective amount
of a lubricant composition and (b) working the metal workpiece,
wherein the lubricant composition comprises (i) a neutral alkyl
phosphorus compound selected from the group consisting of a neutral
alkyl phosphate of the general formula I ##STR17## wherein R.sub.1,
R.sub.2 and R.sub.3 are the same or different and are alkyl groups
of 1 to 18 carbon atoms; a neutral alkoxyalkyl phosphate of the
general formula IV ##STR18## wherein R.sub.4, R.sub.6 and R.sub.8
are --C.sub.2H.sub.4 or C.sub.3H.sub.8 and R.sub.5, R.sub.7 and
R.sub.9 are the same or different and are alkyl groups of 1 to 8
carbon atoms and n is 1 to 6; (iii) a neutral dialkylalkoxyalkyl
phosphate of the general formula XI ##STR19## wherein R.sub.2 and
R.sub.3 are the same as in formula I above and R.sub.4 and R.sub.5
are the same as in formula IV above and mixtures thereof, and (ii)
a sulphur carrier containing active or inactive sulphur and which
is selected from the group consisting of sulphurised synthetic
esters, sulphurised vegetable oils and fats, metal sulphonates,
dialkylpolysulphides and mixtures thereof.
12. The method according to claim 11 wherein the neutral alkyl
phosphorus compound and the sulphur carrier of the lubricant
composition are present in a weight ratio of P to S content from
1:50 to 1:1.
13. The method according to claim 11 wherein the neutral alkyl
phosphorus compound and the sulphur carrier of the lubricant
composition are present in a weight ratio of P to S content from
1:1 to 1:30.
14. The method according to claim 11 wherein the phosphorus
compound of the lubricant composition is selected from the group
consisting of triisobutyl phosphate, tri-n-butyl phosphate,
triisopropyl phosphate, triocyl phosphate, tri-2-ethylhexyl
phosphate, tributoxyethyl phosphate, butoxyethyldioctyl phosphate
and mixtures thereof.
15. The method according to claim 11 wherein the sulphur carrier of
the lubricant composition is selected from the group consisting of
a sulphurised fatty acid, a dialkylpentasulphide and mixtures
thereof.
16. The method according to claim 11 wherein the lubricant
composition is a metal working fluid, a gear oil, an extreme
pressure turbine oil or a hydraulic oil.
Description
[0001] This invention relates to novel lubricant compositions that
are useful as lubricants in high load carrying oils, e.g. metal
working fluids, gear oils, extreme pressure turbine oils and
hydraulic oils. The lubricant compositions of the invention are
especially useful in metal working fluids.
[0002] The cutting of metal involves the expenditure of significant
amounts of energy and the development of high temperatures as the
cutting tool removes metal from the workpiece. In order to reduce
the energy consumed, obtain a long life for the cutting tool and a
high surface finish on the workpiece, it is essential that the
lubricant used is able to operate efficiently under the conditions
of operation. This means essentially that it is capable of working
at very high loads and quickly removing the heat generated by the
cutting process. Mineral oil alone does not have sufficient
lubricity to perform this function and it is necessary to
incorporate additives to enhance this aspect of the oil's
performance.
[0003] In the past the most common extreme pressure additives have
been those containing chlorine (for example C14-17 chlorinated
paraffins), phosphorus containing additives in the form of neutral
triaryl phosphates, alkyl or alkylaryl acid phosphates and
alkylpolyalkoxy or alkylarylpolyalkoxy acid phosphates and sulphur
carriers (for example sulphurised olefins, sulphurised esters, and
sulphurised fats). The level of performance offered by the
different additives varies depending on the temperatures at which
the active species are released to form a salt layer at the metal
surface. This in turn depends on the speed and feed rate of the
cutting tool, the type and hardness of the alloy being machined and
the specific machining operation.
[0004] The severity of the application would largely determine the
chemical nature of the selected extreme pressure additive, the
level of use and whether a combination of additives might be
preferable. For example, if the application was not too heavy duty
it might use a low concentration of an extreme pressure additive
(such as a chlorinated paraffin or a phosphate ester). While for
heavier duty applications, higher concentrations of the different
types of extreme pressure additives or mixtures of these additives
are utilised by the formulator.
[0005] None of the commonly used extreme pressure additives is
without its disadvantages. Sulphur can produce staining of
workpieces derived from non-ferrous alloys at high concentrations
and also an unattractive odour as the carrier decomposes to release
the sulphur. Problems associated with the usage of chlorine stem
from concerns about disposal of the cutting fluid These compounds
can also produce hydrochloric acid on decomposition which can cause
corrosion of the workpiece and equipment in the environment of the
machining operation.
[0006] In addition to mineral oil as the "carrier" for the extreme
pressure/antiwear additives, and usually for applications which are
more severe, oil in water emulsions and water based solutions are
also commonly used in applications which require less lubricity.
However in all these fluids, additives are required to improve the
lubrication performance of the fluid.
[0007] The type of phosphorus-containing additives which are found
in metal working fluids are typically alkyl or alkylaryl acid
phosphates and alkylpolyalkoxy or alkylarylpolyalkoxy acid
phosphates used either as the free acid or neutralised with basic
materials such as alkanolamines and caustic soda e.g. products sold
under the trade marks of Lubrhophos and Rhodafac; neutral triaryl
phosphates e.g. synthetic isopropylated phenyl phosphates such as
are available commercially under the Durad trde mark.
[0008] Concern has been expressed regarding the use of neutral or
acid aryl and acid alkylaryl phosphates lest the used fluid
containing phenolic compounds (arising largely from the hydrolysis
of the phosphates) should escape into the environment and
contaminate water courses. Acid phosphate esters can also become
less effective as extreme pressure additives when neutralised and
are also unstable when subjected to hard water.
[0009] One objective of the present invention is to provide a novel
lubricant composition which improves the cutting performance of
both neat oil and water based cutting fluids. Another objective of
the present invention is to replace acid phosphates as extreme
pressure/anti wear additives in metal working applications. This
objective has been achieved by the combination of certain neutral
alkyl phosphorus compounds with certain sulphur carriers.
[0010] According to the present invention, there is provided a
lubricant composition for a high load carrying oil said lubricating
composition comprising: [0011] (a) a neutral alkyl phosphorus
compound selected from those corresponding to the following general
formulae: [0012] (i) neutral alkyl phosphates ##STR1## [0013]
wherein R.sub.1, R.sub.2 and R.sub.3 are the same or different and
are alkyl groups with 1 to 18 carbon atoms, preferably 4 to 12
carbon atoms. [0014] (ii) neutral alkyl phosphonates ##STR2##
[0015] wherein R.sub.1, R.sub.1 and R.sub.3 have the same meaning
as in I above. [0016] (iii) neutral alkyl phosphinates ##STR3##
[0017] wherein R.sub.1, R.sub.2 and R.sub.3 have the same meaning
as in I above. [0018] (iv) neutral alkoxyalkyl phosphates ##STR4##
[0019] wherein R.sub.4, R.sub.6 and R.sub.8 are --C.sub.2H.sub.4 or
C.sub.3H.sub.8 and R.sub.5, R.sub.7 and R.sub.9 are the same or
different and are alkyl groups with 1 to 8 carbon atoms and n is 1
to 6. [0020] (v) neutral alkoxyalkyl phosphonates ##STR5## [0021]
wherein R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8 and R.sub.9 and
n have the same meanings as in IV above. [0022] (vi) neutral
alkoxyalkyl phosphinates ##STR6## [0023] wherein R.sub.4, R.sub.5,
R.sub.6, R.sub.7, R.sub.8 and R.sub.9 and n have the same meanings
as in IV above. [0024] (vii) neutral alkyldialkoxyalkyl
phosphonates ##STR7## [0025] wherein R.sub.4, R.sub.5, R.sub.6,
R.sub.7 and n have the same meanings as in IV above and R.sub.10 is
an alkyl group with 1 to 18 carbon atoms, preferably 4 to 12 carbon
atoms. [0026] (viii) neutral dialkylalkoxyalkyl phosphinates
##STR8## [0027] wherein R.sub.4, R.sub.5 and n have the same
meanings as in IV above and R.sub.10 and R.sub.11 are the same or
different and are alkyl groups with 1 to 18 carbon atoms,
preferably 4 to 12 carbon atoms. [0028] (ix) neutral alkoxyalkyl
dialkyl phosphonates ##STR9## [0029] wherein R.sub.6, R.sub.7 and n
have the same meanings as in IV above and R.sub.12 and R.sub.13 are
the same or different and are alkyl groups with 1 to 18 carbon
atoms, preferably 4 to 12 carbon atoms. [0030] (x) neutral
dialkoxyalkylalkyl phosphinates ##STR10## [0031] wherein R.sub.6,
R.sub.7, R.sub.8, R.sub.9 and n have the same meanings as in IV
above and R.sub.12 is an alkyl group with 1 to 18 carbon atoms,
preferably 4 to 12 carbon atoms. [0032] (xi) neutral
dialkylalkoxyalkyl phosphates ##STR11## [0033] wherein R.sub.2 and
R.sub.3 are the same as in I above and R.sub.4 and R.sub.5 are the
same as in IV above. [0034] (xii) neutral alkyl phosphites
##STR12## [0035] wherein R.sub.1, R.sub.2, R.sub.3 have the same
meaning as in I above. [0036] (xiii) neutral alkoxyalkyl phosphites
##STR13## [0037] wherein R.sub.4, R.sub.5, R.sub.6, R.sub.7,
R.sub.8, R.sub.9 and n have the same meanings as in IV above.
[0038] and (b) a sulphur carrier containing active or inactive
sulphur.
[0039] The lubricant composition of the invention can comprise one
or more of the compounds of general formulae I to XIII.
[0040] Advantageously, the neutral alkyl phosphorus compound and
the sulphur carrier are utilised in a weight ratio of P to S
content from 1:50 to 1:1, preferably a weight ratio of 1:1 to
1:30.
[0041] Examples of compounds of the general formulae I to XIII are
as follows: [0042] I--triisobutyl phosphate, tributyl phosphate,
triisopropyl phosphate, trioctyl phosphate and tri-2-ethylhexyl
phosphate [0043] II--butyl dibutyl phosphonate and octyl dioctyl
phosphonate [0044] III--dioctyl octyl phosphinate [0045]
IV--tributoxyethyl phosphate [0046] V--butoxyethyl dibutoxyethyl
phosphonate [0047] VI--dibutoxyethyl butoxyethyl phosphinate [0048]
VII--octyl dibutoxyethyl phosphonate [0049] VIII--dioctyl
butoxyethyl phosphinate [0050] IX--butoxyethyl dioctyl phosphonate
[0051] X--dibutoxyethyl octyl phosphinate [0052] XI--butoxyethyl
dioctyl phosphate [0053] XII--trilauryl phosphite, trioleyl
phosphite, trioctyl phosphite and tributyl phosphite [0054]
XIII--tributoxyethyl phosphite
[0055] Preferred sulphur carriers are selected from at least one of
sulphurised synthetic esters, sulphurised hydrocarbons (e.g.
sulphurised olefins), sulphurised vegetable oils and fats, metal
sulphonates, metal dialkyldithiophosphates and triaryl
phosphorothionates.
[0056] The sulphur carriers serve to release sulphur at the cutting
face of the workpiece where it reacts to form a lubricating film at
relatively high temperatures.
[0057] The present invention is also a high load carrying oil which
contains a lubricant composition as described above.
[0058] The high load carrying oil may be a metal working fluid, a
gear oil, an extreme pressure turbine oil or a hydraulic oil.
[0059] From another aspect, the present invention is also a method
for working metal comprising (a) contacting a metal workpiece with
a lubricant composition as described above and (b) working the
metal workpiece.
[0060] The lubricant composition of the invention can include other
components conventional in the art, e.g. surfactants, non-ionic
alcohols.
[0061] Embodiments of the invention will now be described simply by
way of example: [0062] 1) As sulphur carriers, Rhein Chemie
products RC 2526 (a sulphurised fatty acid ester with 26% total
sulphur of which 15% is active) and RC 2540 (a dialkylpentasulphide
with 40% total sulphur of which 36% is active). [0063] 2) As an
alkylpolyalkoxy acid phosphate, (mixed mono- and di-), Lubrhophos
LB400 ex Rhodia Chemicals which is based on oleyl alcohol reacted
with ethylene oxide and then the product is reacted with phosphorus
pentoxide. This product is oil soluble and recommended as an EP
additive for cutting oils. [0064] 3) Durad TiBP which is
tri-isobutyl phosphate [0065] 4) Durad TBEP which is tributoxyethyl
phosphate
[0066] Durad is a registered trade mark of Great Lakes Chemical
Corporation.
[0067] In the following tests, an automatic drilling machine is
used to drill holes in metal discs 40 mm thick. The holes are 18 mm
deep while, for oil-based cutting fluids, the drill feeds and
speeds were 0.13 mm/rev (or 156 mm/min) and 1200 rpm respectively.
Tests were carried out until the drill failed either due to
breakage or to excessive wear. The average of at least duplicate
test results are quoted.
(A) Drill Life Test Data on Mild Steel Using Neat Oil: Durad
TiBP/Sulphur Carriers as Replacements for Chlorparaffins
[0068] The metal used was EN24T carbon steel; the drill feeds and
speeds were as indicated below and the base stock was an ISO VG 22
paraffinic oil. In this case the S/P ratio was 13:1. The
formulation containing Durad TiBP is seen to be significantly more
active than the chlorparaffin. TABLE-US-00001 Formulation (w/w) 1 2
3 TiBP 0.6 -- Sulphur carrier (36.7% sulphur - all active) 2.5 --
4.3 Chlorparaffin (40% chlorine) -- 8.0 -- ISO VG 22 paraffinic oil
96.9 92.0 95.7 Holes drilled to failure 280 140 100
(B) Drill Life Tests on Stainless Steel Using Neat Oil: A
Comparison with Acid Phosphates
[0069] Stainless steel type 304 was used for this study. The
sulphur carriers used were a 4:1 mix of a sulphurised fatty acid
ester (26% total sulphur of which 15% is active) and a dialkyl
polysulphide (40% total sulphur of which 36% is active). The levels
of sulphur and phosphorus used were 1.5% and 0.5% respectively
giving an S/P ratio of 3:1. As for previous tests the oil used was
an ISO VG 22 Group 1 base. TABLE-US-00002 Formulations (w/w) 4 5 6
7 Sulphur carriers 5.2 5.2 5.2 5.2 Durad TiBP -- 4.17 -- -- Durad
TBEP -- -- 6.4 -- Oleyl acid phosphate -- -- -- 10.0 Neat Oil 94.8
90.63 68.4 84.8 Holes drilled to failure 84 432 >>500 18
[0070] The quality of swarf associated with Durad TBEP in the above
test was regarded as excellent throughout. In fact no drill
failures occurred with this formulation.
(C) Performance of S/P Combinations on Stainless Steel Using
Macro-Emulsions
[0071] The conditions for this test were somewhat different. In
order to satisfactorily machine the stainless steel with the
emulsion the conditions were modified to a feed rate of 70 mm/min
and a speed of 700 rpm-slightly more severe conditions than were
recommended by the drill manufacturers. The same sulphur carriers
were used as in the previous test on stainless. A concentrate of
the phosphate and sulphur carriers with emulsifiers, corrosion
inhibitors, antifoams etc was first prepared in aqueous solution
with the part addition of the triethanolamine base. This
concentrate was subsequently added to a 60 solvent pale oil
(naphthenic type) containing a further small amount of emulsifier
and triethanolamine to produce an emulsion concentrate. This
emulsion concentrate was then diluted to 4% to produce the working
fluid. Tap water with a hardness of 160 ppm calcium carbonate was
used throughout. In this test, the concentration of the sulphur and
phosphorus in the final emulsion were 0.36% sulphur and 0.012%
phosphorus (a 30:1 ratio). The table below gives the approximate
formulation of the concentrate before dilution. TABLE-US-00003
Formulation (%) 8 9 Sulphur carriers 3.12 3.12 Durad TiBP -- 0.25
Emulsifier/inhibitor mixture 2.84 4.99 Triethanolamine 3.04 3.04
Mineral oil 46.0 46.0 Water 45.0 42.6 Holes drilled to failure 214
>>500
[0072] In this test Durad TiBP is seen to be a most effective
additive which in combination with the sulphur carriers shows a
significant improvement over the sulphur carriers alone.
(D) Drill Life Test Data on Stainless Steel Using Neat Oil: A
Comparison of Tributoxyethyl phosphate (TBEP) with Dioctyl octyl
phosphonate
[0073] The sulphur carriers used RC2526 and RC2540 were the same as
used in the previous Examples.
[0074] Concentrations used were 1.5% sulphur and 0.5% phosphorus in
an ISO VG 22 paraffinic type neat oil (i.e. the same as
before).
[0075] Stainless steel type 304 was used for this study.
[0076] The drill feed rate was 150 mm/min and the speed was 1500
rpm. The depth of hole was 18 mm. TABLE-US-00004 Formulation (w/w)
Holes drilled to failure Sulphur carriers alone 56 Sulphur carriers
plus Dioctyl octyl phosphonate 336 Sulphur carriers plus TBEP
500+
[0077] The above results show that although both phosphorus
additives showed enhanced activity, TBEP was the higher of the
two.
[0078] N.B. In the above tests, an automatic drilling machine is
used to drill holes in metal discs 40 mm thick. The holes are 18 mm
deep, while drill feeds and speeds are normally 0.13 mm/rev (or 156
mm/min) and 1200 rpm respectively. Tests were carried out until the
drill failed either due to breakage or to excessive wear. The
average of at least duplicate test results are quoted.
[0079] Although lubricity additives such as fatty oils and long
chain esters can be used in cutting fluids, these were not included
in the formulations shown above.
CONCLUSIONS
[0080] A major benefit of the present invention is that neutral
alkyl phosphorus compounds provide a synergistic performance with
sulphur carriers in both neat oil and aqueous cutting fluids on
both mild steel and stainless steel. Such a synergistic combination
enables the formulation of cutting fluids with the following
properties: [0081] (a) no chlorine present; [0082] (b) the
elimination of the production of phenolic degradation products;
[0083] (c) a possible reduction in the level of sulphur in the oil;
[0084] (d) improved lubrication performance; and [0085] (e)
extended drill life in metal cutting applications.
[0086] The use of neutral alkyl phosphorus compounds also allows
higher levels of phosphorus to be used when necessary. Where acid
phosphates are used, the acidity effectively limits the level of
phosphorus that can be used because the acid can become corrosive
at high levels. This allows for more flexibility in formulating
mixtures of P/S and higher levels where necessary depending on the
severity of the worling process.
[0087] Benefits from the use of the synergistic combination of the
invention in applications other than metal cutting processes
include: [0088] (i) An increase in the level of performance without
substantially increasing the level of the sulphur carriers. These
can adversely affect the oxidation stability and corrosive
tendencies of the formulation. [0089] (ii) Alternatively, for the
same level of performance, it is possible to lower the sulphur
carrier level thereby favourably impacting the
stability/corrosivity of the formulation.
* * * * *