U.S. patent application number 16/001650 was filed with the patent office on 2018-10-11 for organosiloxane compositions.
The applicant listed for this patent is Dow Silicones Corporation. Invention is credited to Lorry DEKLIPPEL, Michael Salvatore FERRITTO, Don Lee KLEYER, Andreas STAMMER, Herbert STOEGBAUER, Vesna WEBER.
Application Number | 20180291299 16/001650 |
Document ID | / |
Family ID | 52023655 |
Filed Date | 2018-10-11 |
United States Patent
Application |
20180291299 |
Kind Code |
A1 |
DEKLIPPEL; Lorry ; et
al. |
October 11, 2018 |
ORGANOSILOXANE COMPOSITIONS
Abstract
A copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl
siloxane obtainable by reacting a dispersion of ingredient (i) an
alkylfluoroalkyl siloxane and ingredient (ii) one or more
polyalkylphenyl siloxane(s) in the presence of ingredient (iii) a
basic catalyst at a temperature of between 40.degree. C. to
300.degree. C.
Inventors: |
DEKLIPPEL; Lorry; (Pieton,
BE) ; FERRITTO; Michael Salvatore; (Midland, MI)
; KLEYER; Don Lee; (Hemlock, MI) ; STAMMER;
Andreas; (Pont-a-Celles, BE) ; STOEGBAUER;
Herbert; (Huenfelden, DE) ; WEBER; Vesna;
(Appenheim, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dow Silicones Corporation |
Midland |
MI |
US |
|
|
Family ID: |
52023655 |
Appl. No.: |
16/001650 |
Filed: |
June 6, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15038155 |
May 20, 2016 |
10011801 |
|
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PCT/US2014/066499 |
Nov 20, 2014 |
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16001650 |
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61906690 |
Nov 20, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10N 2030/10 20130101;
C10M 2229/0515 20130101; C10M 2213/06 20130101; C10N 2040/25
20130101; C08G 77/80 20130101; C10M 2219/068 20130101; C08G 77/24
20130101; C10M 107/50 20130101; C10N 2030/06 20130101; C08L 83/04
20130101; C10M 2223/045 20130101; C10N 2040/02 20130101; C10N
2040/04 20130101; C10M 2229/0515 20130101; C10M 2229/0425
20130101 |
International
Class: |
C10M 107/50 20060101
C10M107/50; C08G 77/24 20060101 C08G077/24; C08G 77/00 20060101
C08G077/00; C08L 83/04 20060101 C08L083/04 |
Claims
1. A copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl
siloxane, the copolymer prepared by reacting a dispersion of:
ingredient (i) an alkylfluoroalkyl siloxane comprising units of the
following structure; ##STR00012## where each R is independently
selected from an alkyl group having from 1 to 6 carbon atoms, n is
an integer, x is zero or an integer from 1 to 6, and R.sup.1 is a
perfluoroalkyl group which is either linear or branched; and
ingredient (ii) one or more polyalkylphenyl siloxane(s) comprising
units of the following structure; ##STR00013## where each R.sup.2
is independently selected from an alkyl group having from 1 to 6
carbon atoms and t is an integer; in the presence of ingredient
(iii) a basic catalyst at a temperature of between 40.degree. C. to
300.degree. C.; wherein ingredient (ii) comprises a trialkylsilyl
terminated siloxane.
2. (canceled)
3. The copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl
siloxane in accordance with claim 1, wherein the alkylfluoroalkyl
siloxane is linear or branched and has viscosity of from 100 cst to
100,000 cst (100 mm.sup.2s.sup.-1 to 100,000 mm.sup.2s.sup.-1) at
25.degree. C. with a capillary viscometer according to ASTM
D445-06.
4. The copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl
siloxane in accordance with claim 1, wherein the alkylfluoroalkyl
siloxane is cyclic and n is from 3 to 15.
5. The copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl
siloxane in accordance with claim 1, wherein R.sup.1 is a
perfluoroalkyl group which is either linear or branched and
contains from 1 to 12 carbon atoms.
6. The copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl
siloxane in accordance with claim 5, wherein the perfluoroalkyl
group is selected from perfluoromethyl, perfluoroethyl,
perfluoro-n-propyl, perfluoro-iso-propyl, perfluoro-n-butyl,
perfluoro-iso-butyl, perfluoro-tert-butyl, perfluoro-n-pentyl,
perfluoro-isopentyl, perfluoroneo-pentyl, perfluorohexyl,
perfluoroheptyl, perfluorooctyl, perfluorononyl, perfluorodecyl,
perfluoroundecyl and perfluorododecyl or a mixture thereof.
7. The copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl
siloxane in accordance with claim 1, wherein the polyalkylphenyl
siloxane has a viscosity of from 250 cst to 50,000 cst (250
mm.sup.2s.sup.-1 to 50,000 mm.sup.2s.sup.-1) at 25.degree. C. with
a capillary viscometer according to ASTM D445-06.
8. The copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl
siloxane in accordance with claim 1, wherein ingredient (i) and
ingredient (ii) are intermixed in a ratio of from 10 weight % of
ingredient (i):90 weight % of ingredient (ii) to 90 weight % of
ingredient (i):10 weight % of ingredient (ii) based on the total
weight of ingredient (i) and ingredient (ii) being 100 weight
%.
9. The copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl
siloxane in accordance with claim 1, wherein ingredient (ii) is a
mixture of polyalkylphenyl siloxanes including the trialkylsilyl
terminated siloxane.
10. The copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl
siloxane in accordance with claim 1, wherein the basic catalyst is
selected from one or more alkali metal hydroxides, alkali metal
alkoxides or complexes of alkali metal hydroxides and an alcohol,
alkali metal silanolates, tetra-alkyl phosphonium hydroxides and
tetra-alkyl phosphonium silanolates, phosphonitrile halides,
phosphazene bases and the catalyst derived by the reaction of a
tetra-alkyl ammonium hydroxide and a siloxane tetramer.
11. The copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl
siloxane in accordance with claim 10, wherein the basic catalyst is
potassium hydroxide.
12. A lubricant consisting of the copolymer in accordance with
claim 1 and at least one additive.
13. A lubricant comprising: the copolymer in accordance with claim
1; and one or more additives selected from friction modifiers,
anti-wear additives, extreme pressure additives, seal swelling
agents, rust and corrosion inhibitors, thickeners, Viscosity Index
improvers, pour point depressants, anti-oxidants, free-radical
scavengers, hydroperoxide decomposers, metal passivators, surface
active agents, emulsifiers, demulsifiers, defoamants,
compatibilizers, dispersants, and mixtures thereof and/or deposit
control additives, film forming additives, tackifiers,
antimicrobials, additives for biodegradable lubricants, haze
inhibitors, chromophores, and limited slip additives.
14. The lubricant in accordance with claim 13, comprising from 0.1
to 10 weight % of the additive(s) and 90 to 99.9 weight % of the
copolymer.
15. A lubricant grease comprising: 0 to 10 weight % of one or more
additives (excluding thickeners); 1 to 55 weight % of thickeners;
and the remainder being the copolymer in accordance with claim
1.
16-25. (canceled)
26. A method for making a lubricant comprising mixing the copolymer
in accordance with claim 1 and one or more additives selected from
friction modifiers, anti-wear additives, extreme pressure
additives, seal swelling agents, rust and corrosion inhibitors,
thickeners, Viscosity Index improvers, pour point depressants,
anti-oxidants, free-radical scavengers, hydroperoxide decomposers,
metal passivators, surface active agents, emulsifiers,
demulsifiers, defoamants, compatibilizers, dispersants, and
mixtures thereof and/or deposit control additives, film forming
additives, tackifiers, antimicrobials, additives for biodegradable
lubricants, haze inhibitors, chromophores, and limited slip
additives.
27. (canceled)
28. A method to lubricate metal-metal or plastic-plastic surfaces
comprising: obtaining the lubricant composition in accordance with
claim 13; and lubricating the surface with the lubricant
composition.
29-30. (canceled)
31. The copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl
siloxane in accordance with claim 9, wherein ingredient (ii)
comprises the trialkylsilyl terminated siloxane and a
dialkylhydroxy terminated siloxane.
32. The copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl
siloxane in accordance with claim 1, wherein the copolymer is
further prepared by stirring ingredients i) and ii) to form the
dispersion and at least one of: heating the dispersion and holding
the temperature between 100.degree. C. and 300.degree. C. during
reaction; sweeping the dispersion with nitrogen during reaction;
cooling the dispersion after reaction; neutralizing the basic
catalyst; and stripping the dispersion after reaction.
Description
[0001] This relates to copolymers of polyalkylphenyl siloxanes and
alkylfluoroalkyl siloxanes, a process for their preparation and the
uses thereof.
[0002] The viscosity of fluids which are used in lubricant
compositions tend to vary with temperature. Typically fluid
viscosities decrease with increasing temperature and vice versa,
and these variations can have a significant effect on the
lubricating nature of the lubricating composition. Amongst their
many desired properties polyalkylphenylsiloxane based materials in
particular phenylmethylsiloxanes, are known to have excellent high
and low temperature behaviours, in that their viscosities vary far
less under the influence of temperature, particularly at high
(above 200.degree. C.) temperatures and low (below -60.degree. C.)
temperatures which can be involved in lubrication applications.
This feature alone makes them potentially desirable as ingredients
in lubricant compositions because when present in a lubrication
composition they cause the composition to have advantageously high
Viscosity Index values which are desirable in lubricants.
[0003] Viscosity Index (VI) is an empirical, unitless number which
indicates the rate of change in the viscosity of an oil within a
given temperature range, usually between 40.degree. C. and
100.degree. C. The Viscosity Index is defined as the gradient of
kinematic viscosities of a material, between 40.degree. C. and
100.degree. C. When the Viscosity Index is low (below 100) the
fluid exhibits a relatively large change of viscosity with
temperature. When the Viscosity Index is high (above 150), the
fluid exhibits relatively little change of viscosity with
temperature. In a variety of applications, a high or very high
Viscosity Index is preferred.
[0004] Unfortunately, however the currently available
polyalkylphenylsiloxanes such as polymethylphenylsiloxanes (PMPS)
and compositions containing them show poor lubrication properties
in respect to load carrying and anti wear properties, especially in
metal to metal lubrication which limits the lubrication
applications in which they can be utilised.
[0005] Alkylfluoroalkyl siloxanes for example
methyltrilfuoropropylsiloxanes (MTFPS), such as trimethyl silyl
terminated methyltrifluorosiloxanes as depicted below show better
lubrication than polyalkylphenylsiloxanes for example
phenylmethylsiloxanes (PMPS) and other siloxane based fluids such
as polydimethylsiloxanes (PDMS).
##STR00001##
Trimethyl Silyl Terminated Methyltrifluoropropylsiloxane
[0006] However, MTFPS are not as stable at high temperatures (i.e.
>200.degree. C.) and therefore despite their lubricating
properties the lubrication industry tends to rely on
perfluoropolyether (PFPE) based materials to provide sufficient
lubrication properties in respect to load carrying and anti wear
properties in metal to metal lubrication in extreme (high and low)
temperature conditions. Hence, there is a need for a more cost
effective lubricant that can operate over a wide temperature range,
has a high VI and good metal to metal lubrication.
[0007] Whilst a mixture of polyalkylphenyl siloxanes e.g. PMPS and
alkylfluoroalkyl siloxanes e.g. MTFPS may appear a potential
alternative to the use of PFPE, this is not possible because these
siloxanes are effectively immiscible.
[0008] GB1558816 describes a fluorosiloxydiphenylsiloxy block
copolymer and a process for producing the
fluorosiloxydiphenylsiloxy block copolymer by reacting
perfluoroalkylethylene substituted cyclic trisiloxane in the
presence of a solvent promoter e.g. tetrahydrofuran, in the
presence of a dilithium compound catalyst and then adding a
diphenyl cyclic trisiloxane and allowing the reaction to go to the
completion. Similar polymers are discussed in U.S. Pat. No.
4,075,169. The use of trifluoropropylmethylsiloxane gums in sealant
formulations are described in U.S. Pat. No. 3,192,175 and methods
for preparing fluorinated siloxanes are described in U.S. Pat. No.
5,914,420 and U.S. Pat. No. 4,577,040.
[0009] Surprisingly, despite their incompatibility, a method for
copolymerising polyalkylphenyl siloxanes and alkylfluoroalkyl
siloxanes has now been identified and the resulting copolymer has
been found to provide unexpected advantages and as such is able to
provide a silicone based alternative to PFPE for high temperature
lubrication of metal-metal joints.
[0010] There is provided herein a copolymer of polyalkylphenyl
siloxane and alkylfluoroalkyl siloxane obtainable by reacting a
dispersion of an alkylfluoroalkyl siloxane comprising units of the
following structure:
##STR00002##
in which each R group may be the same or different and is selected
from an alkyl having from 1 to 6 carbon atoms, alternatively 1 to 3
carbon atoms, alternatively R is methyl or ethyl, n is an integer,
x is zero or an integer from 1 to 6 and R.sup.1 is a perfluoroalkyl
group which is either linear or branched and may contain from 1 to
12 carbon atoms and one or more polyalkylphenyl siloxane(s)
comprising units of the following structure:
##STR00003##
in which each R.sup.2 group is the same or different and is
selected from an alkyl group having from 1 to 6 carbon atoms,
alternatively 1 to 3 carbon atoms, alternatively R is methyl or
ethyl and t is an integer; at a temperature between 40.degree. C.
to 300.degree. C., alternatively 40.degree. C. to 250.degree. C. in
the presence of a basic catalyst.
[0011] There is further provided herein a method for preparing a
copolymer of polyalkylphenyl siloxane and alkylfluoroalkyl siloxane
reacting a dispersion of an alkylfluoroalkyl siloxane comprising
units of the following structure:
##STR00004##
in which each R group may be the same or different and is selected
from an alkyl having from 1 to 6 carbon atoms, alternatively 1 to 3
carbon atoms, alternatively R is methyl or ethyl, n is an integer,
x is zero or an integer of from 1 to 6 inclusive and R.sup.1 is a
perfluoroalkyl group which is either linear or branched and may
contain from 1 to 12 carbon atoms and one or more polyalkylphenyl
siloxane comprising units of the following structure:
##STR00005##
in which each R.sup.2 group is the same or different and is
selected from a linear or branched alkyl group having from 1 to 6
carbon atoms, alternatively 1 to 3 carbon atoms, alternatively R is
methyl or ethyl and t is an integer; at a temperature between
40.degree. C. to 300.degree. C., alternatively 40.degree. C. to
250.degree. C. in the presence of a basic catalyst.
[0012] There is still further provided a copolymer of
polyalkylphenyl siloxane and alkylfluoroalkyl siloxane comprising
units of the following structure:
##STR00006##
in which each R group may be the same or different and is selected
from an alkyl having from 1 to 6 carbon atoms, n is an integer, x
is zero or an integer from 1 to 6 and R.sup.1 is a perfluoroalkyl
group which is either linear or branched and may contain from 1 to
12 carbon atoms; and units of the following structure:
##STR00007##
in which each R.sup.2 group is the same or different and is
selected from an alkyl group having from 1 to 6 carbon atoms; and t
is an integer; wherein the copolymer is a random copolymer, a block
copolymer or a mixture thereof. The polymer is obtainable by the
method described above.
[0013] As hereinbefore described, the alkylfluoroalkyl siloxane
comprises units of the following structure:
##STR00008##
[0014] The alkylfluoroalkyl siloxane may have a linear, branched or
cyclic structure. In the case of cyclic alkylfluoroalkyl siloxanes
the cyclic material will generally contain between 3 and 15 of the
above siloxane units. Each R group may be the same or different and
is selected from an alkyl group having from 1 to 6 carbon atoms.
Alternatively each R group may have from 1 to 3 carbon atoms;
alternatively R is methyl or ethyl.
[0015] R.sup.1 is a perfluoroalkyl group which is either linear or
branched and may contain from 1 to 12 carbon atoms. Examples of
suitable perfluoroalkyl groups include, perfluoromethyl,
perfluoroethyl, perfluoro-n-propyl, perfluoro-iso-propyl,
perfluoro-n-butyl, perfluoro-iso-butyl, perfluoro-tert-butyl,
perfluoro-n-pentyl, perfluoro-isopentyl, perfluoroneo-pentyl,
perfluorohexyl, perfluoroheptyl, perfluorooctyl, perfluorononyl,
perfluorodecyl, perfluoroundecyl and perfluorododecyl or a mixture
thereof.
[0016] Typically n in the alkylfluoroalkyl siloxane composition is
preferably an integer greater than 1. The value of n is in reality
commensurate with the viscosity of the alkylfluoroalkyl siloxane
which is typically between 100 cst and 100 000 cst, (100
mm.sup.2s.sup.-1 and 100 000 mm.sup.2s.sup.-1) i.e. n is an integer
resulting in the alkylfluoroalkyl siloxane having a viscosity in
the range above. The viscosity of the polyalkylphenyl siloxane may
alternatively be from 250 cst to 50 000 cst, (250 mm.sup.2s.sup.-1
to 50 000 mm.sup.2s.sup.-1) alternatively from 250 cst to 10 000
cst (250 mm.sup.2s.sup.-1 to 10 000 mm.sup.2s.sup.-1). The value of
x is zero or an integer of from 1 to 6 inclusive, typically x is 1,
2 or 3, alternatively 2 or 3.
[0017] Viscosity values given throughout this document are either
shown as dynamic viscosity values in mPas measured with a
rotational viscometer Rheoplus from Anton Paar or as kinematic
viscosity values in cSt (mm.sup.2s.sup.-1) measured with a
capillary viscometer according to ASTM D445-06 and are measured at
room temperature unless otherwise indicated.
[0018] When linear or branched, the alkylfluoroalkyl siloxane may
have terminal silyl groups comprising alkyl groups containing 1 to
6 carbon atoms, hydroxyl groups and/or alkoxy groups containing 1
to 6 carbon atoms. The terminal silyl groups of the
alkylfluoroalkyl siloxane may be of the structure:
--Si(R.sup.3).sub.m(R.sup.4).sub.3-m
wherein R.sup.3 is an alkyl group having 1 to 6 carbon atoms
alternatively methyl or ethyl and R.sup.4 is OH or an alkoxy group
having between 1 and 6 carbon atoms alternatively OH, and m is 0,
1, 2 or 3, alternatively m is 1, 2 or 3, alternatively m is 2 or 3.
The terminal silyl groups are bonded to the polymer backbone via an
oxygen.
[0019] In one alternative the alkylfluoroalkyl siloxane is an
MTFPS, typically comprising trialkylsilyl terminal groups.
[0020] The polyalkylphenyl siloxane(s) as hereinbefore described
comprise(s) units of the following structure:
##STR00009##
in which each R.sup.2 group is the same or different and is
selected from a linear or branched alkyl group having from 1 to 6
carbon atoms, alternatively 1 to 3 carbon atoms, alternatively R is
methyl or ethyl; Typically tin the polyalkylphenyl siloxane(s) is
an integer greater than 1. The value of t is commensurate with the
viscosity of the or each polyalkylphenyl siloxane which is
typically between 100 cst and 100 000 cst, (100 mm.sup.2s.sup.-1
and 100 000 mm.sup.2s.sup.-1) i.e. t is an integer resulting in the
viscosity range above. The viscosity of the or each polyalkylphenyl
siloxane may alternatively be from 250 cst to 50 000 cst (250
mm.sup.2s.sup.-1 to 50 000 mm.sup.2s.sup.-1), alternatively from
250 cst to 10 000 cst (250 mm.sup.2s.sup.-1 to 10 000
mm.sup.2s.sup.-1). The or in the case of a mixture, one or more
than one polyalkylphenyl siloxane may be linear, branched or
cyclic.
[0021] Similar to the aforementioned alkylfluoroalkyl siloxane,
when linear or branched, the or each polyalkylphenyl siloxane may
have terminal silyl groups comprising alkyl groups containing 1 to
6 carbon atoms, hydroxyl groups and/or alkoxy groups containing 1
to 6 carbon atoms. The terminal silyl groups of the or each
polyalkylphenyl siloxane(s) may be of the structure:
--Si(R.sub.3).sub.m(R.sub.4).sub.3-m
wherein R.sup.3 is an alkyl group having 1 to 6 carbon atoms
alternatively methyl or ethyl and R.sup.4 is OH or an alkoxy group
having between 1 and 6 carbon atoms alternatively OH, and m is 0,
1, 2 or 3, alternatively m is 1, 2 or 3, alternatively m is 2 or 3.
The terminal silyl groups are bonded to the polymer backbone via an
oxygen.
[0022] The polyalkylphenyl siloxane may be one or more PMPS,
typically with trialkylsilyl terminal groups. Alternatively the
polyalkylphenyl siloxane(s) may be a mixture of two polyalkylphenyl
siloxanes, one polyalkylphenyl siloxane having trialkylsilyl
terminal groups and the other polyalkylphenyl siloxane having
dialkylhydroxy terminal groups with in both cases the each alkyl
group being a methyl or ethyl group, alternatively a methyl
group.
[0023] The two polymer types of the reaction composition may be
intermixed in any appropriate combination to make a desired
co-polymer but typically the ratio of the polymer reactants is
between 10% by weight of alkylfluoroalkyl siloxane (e.g. MTFPS) to
90% polyalkylphenyl siloxane (e.g. PMPS) and 90% of
alkylfluoroalkyl siloxane to 10% of polyalkylphenyl siloxane,
alternatively 25% by weight of alkylfluoroalkyl siloxane to 75% by
weight polyalkylphenyl siloxane and 75% of alkylfluoroalkyl
siloxane to 25% of polyalkylphenyl siloxane, alternatively between
40% by weight of alkylfluoroalkyl siloxane and 60% polyalkylphenyl
siloxane and 60% by weight of alkylfluoroalkyl siloxane to 40% of
polyalkylphenyl siloxane, alternatively about 50% of each of
alkylfluoroalkyl siloxane and polyalkylphenyl siloxane. In the case
when the polyalkylphenyl siloxane is in the form of a mixture the
values above are for the cumulative amount of polyalkylphenyl
siloxane in said mixture.
[0024] The reaction typically takes place at a temperature of
between 40.degree. C. to 300.degree. C., alternatively 50.degree.
C. to 300.degree. C., alternatively between 100.degree. C. and
300.degree. C. or between 125.degree. C. and 300.degree. C.,
alternatively, 40.degree. C. to 250.degree. C., alternatively
50.degree. C. to 250.degree. C., alternatively between 100.degree.
C. and 250.degree. C. or between 125.degree. C. and 250.degree.
C.
[0025] Any suitable basic catalyst may be utilised. Examples
include alkali metal hydroxides such as potassium or caesium
hydroxide, alkali metal alkoxides or complexes of alkali metal
hydroxides and an alcohol, alkali metal silanolates such as
potassium silanolate or trimethylpotassium silanolate, tetra-alkyl
phosphonium hydroxides and tetra-alkyl phosphonium silanolates,
phosphonitrile halides (sometimes referred to as acidic
phosphazenes) phosphazene bases and the catalyst derived by the
reaction of a tetra-alkyl ammonium hydroxide and a siloxane
tetramer as described in U.S. Pat. No. 3,433,765. Potassium
hydroxide is particularly preferred as the catalyst. Typically the
catalyst is present in an amount of 0.05 to 1 weight (wt) % of the
starting reaction mixture, alternatively 0.05 to 0.5 wt % of the
starting reaction mixture when present.
[0026] Dispersion polymerization generally affords micron-size
monodisperse particles in a single batch process and may be defined
as a type of precipitation polymerization in which one carries out
the polymerization of a monomer in the presence of a suitable
polymeric stabilizer soluble in the reaction medium (solvent).
Surprisingly in this instance however it was identified that a
solvent was not required for the preparation described above which
is particularly surprising given the immiscibility of the two
ingredients, as current expectations would have suggested the need
for a homogeneous solution of monomer(s) with initiator and
dispersant, in which sterically stabilized polymer particles are
formed by the precipitation of the resulting polymers. Where
appropriate the product of the reaction may have volatiles stripped
therefrom typically at the same or a similar temperature at which
the reaction been carried out but under reduced pressure e.g. from
0.5 to 6 mm Hg (66.66 Pa to 799.92 Pa).
[0027] The copolymer resulting from the reaction described above
can vary in structure depending on the relative amounts of the
starting materials. Hence, the co-polymer resulting from reactions
in which the ratios of the ingredients is between 10% by weight of
alkylfluoroalkyl siloxane to 90% polyalkylphenyl siloxane and 90%
of alkylfluoroalkyl siloxane to 10% of polyalkylphenyl siloxane,
alternatively 25% by weight of alkylfluoroalkyl siloxane to 75% by
weight polyalkylphenyl siloxane and 75% of alkylfluoroalkyl
siloxane to 25% of polyalkylphenyl siloxane, alternatively between
40% by weight of alkylfluoroalkyl siloxane and 60% polyalkylphenyl
siloxane and 60% by weight of alkylfluoroalkyl siloxane to 40% of
polyalkylphenyl siloxane, alternatively about 50% of each of
alkylfluoroalkyl siloxane and polyalkylphenyl siloxane, will
contain groups from each polymer type in approximately the same
ratio when the reaction goes to completion. The nature of the
polymer structure may be completely random, i.e. no pattern of
intermixed groups of:
##STR00010##
as described above and
##STR00011##
as described above. Alternatively the groups in the polymer may be
in multiples of each unit above i.e. a block co-polymer or
alternatively a mixture of the two.
[0028] When used as or in a lubricant the copolymer may be alone,
(i.e. no other ingredients present) or may contain one or more
compatible additives.
[0029] Lubricant additives required in many applications are not
soluble/miscible with alkylfluoroalkyl siloxanes such as MTFPS.
Surprisingly it was found that such commercial additives are
soluble/miscible with the copolymer as hereinbefore described.
Hence, the copolymer prepared as hereinbefore described can be
mixed with suitable additives.
[0030] Lubricant additives may be used to impart or improve certain
properties to the lubricating composition. Such additives include
friction modifiers, anti-wear additives, extreme pressure
additives, seal swelling agents, rust and corrosion inhibitors,
thickeners, Viscosity Index improvers, pour point depressants,
anti-oxidants, free-radical scavengers, hydroperoxide decomposers,
metal passivators, surface active agents such as detergents,
emulsifiers, demulsifiers, defoamants, compatibilizers,
dispersants, and mixtures thereof.
[0031] Further additives include tackifiers, antimicrobials, haze
inhibitors, pigments & dyes.
[0032] Examples of friction modifiers include long-chain fatty
acids and their derivatives, molybdenum compounds, aliphatic amines
or ethoxylated aliphatic amines, ether amines, alkoxylated ether
amines, acylated amines, tertiary amines, aliphatic fatty acid
amides, aliphatic carboxylic acids, aliphatic carboxylic esters,
polyol esters, aliphatic carboxylic ester-amides, imidazolines,
aliphatic phosphonates, aliphatic phosphates, aliphatic
thiophosphonates, aliphatic thiophosphates.
[0033] Examples of anti-wear additives and extreme pressure
additives include organosulfur and organo-phosphorus compounds,
such as organic polysulfides among which alkylpolysulfides;
phosphates among which trihydrocarbyl phosphate, dibutyl hydrogen
phosphate, amine salt of sulfurized dibutyl hydrogen phosphate,
dithiophosphates such as zinc dialkyl dithiophosphates;
dithiocarbamates dihydrocarbyl phosphate; sulfurized olefins, such
as sulfurized isobutylene, and sulfurized fatty acid esters.
[0034] Examples of seal swell agents include esters, adipates,
sebacates, azeealates, phthalates, sulfones such as
3-alkoxytetraalkylene sulfone, substituted sulfolanes, aliphatic
alcohols of 8 to 13 carbon atoms such as tridecyl alcohol,
alkylbenzenes, aromatics, naphthalene depleted aromatic compounds,
mineral oils.
[0035] Examples of rust and corrosion inhibitors include
monocarboxylic acids such as octanoic acid, decanoic acid and
dodecanoic acid; polycarboxylic acids such as dimer and trimer
acids from tall oil fatty acids, oleic acid, linoleic acid;
thiazoles; triazoles such as benzotriazole, decyltriazole,
2-mercapto benzothiazole; thiadiazoles such as
2,5-dimercapto-1,3,4-thiadiazole,
2-mercapto-5-hydrocarbyldithio-1,3,4-thiadiazole; metal
dithiophosphates; ether amines; acid phosphates; amines;
polyethoxylated compounds such as ethoxylated amines; ethoxylated
phenols; ethoxylated alcohols; imidazolines; aminosuccinic
acids.
[0036] Examples of thickeners include metallic soaps such as
lithium soaps and mixtures therewith e.g. lithium complex soaps,
silica, expanded graphite, polytetrafluoroethylene (PTFE) polyurea,
clays such as hectorite or bentonite. The amount of thickener
utilised in a composition may differ depending on application (i.e.
whether the end product is a grease) and the preferred thickener
which may be selected dependent on the intended use for the
lubricant composition. For example soaps may be used in the range
of from 8 to 35% wt of the composition, alternatively 8 to 20% wt
of the composition, alternatively 10 to 15% wt; PTFE may be used in
an amount of from 15 to 55%, alternatively 30 to 55% wt of the
composition and silica when used as a thickener might be used at
comparatively low ranges of from 1-10% wt, alternatively 1 to 5%
wt.
[0037] In some instances, when thickened, the lubricant composition
may become a grease composition.
[0038] Examples of Viscosity Index improvers include
polymethacrylates, olefin copolymers, polyisoalkylene such as
polyisobutylene, styrene-diene copolymers, and styrene-ester
copolymers such as styrenemaleic ester.
[0039] Examples of pour point depressants include wax-alkylated
naphthalenes and phenols, polymethacrylates, styrene-ester
copolymers.
[0040] Examples of anti-oxidants include phenolic antioxidants such
as 2,6-di-tert-butylphenol, tertiary butylated phenols such as
2,6-di-tert-butyl-4-methylphenol,
4,4'-methylenebis(2,6-di-tert-butylphenol),
2,2'-methylenebis(4-methyl6-ter t-butylphenol),
4,4'-thiobis(2-methyl-6-tert-butylphenol); mixed methylene-bridged
polyalkyl phenols; aromatic amine antioxidants; sulfurized phenolic
antioxidants; organic phosphites; amine derivatives such as p-,
p'-dioctyldiphenylamine, N,N'-di-sec-butylphenylenediamine,
4-isopropylaminodiphenylamine, phenyl-.alpha.-naphthyl amine,
ring-alkylated diphenylamines; bisphenols; cinnamic acid
derivatives.
[0041] Examples of free-radical scavengers include zinc dialkyl
dithiophosphates, hindered phenols, and alkylated arylamines.
[0042] Examples of hydroperoxide decomposers include organo-sulfur
compounds and organo-phosphorus compounds.
[0043] Examples of metal passivators include poly-functional
(polydentate) compounds, such as ethylenediaminetetraacetic acid
(EDTA) and salicylaldoxime.
[0044] Examples of surface active agents such as detergents,
dispersants, emulsifiers, demulsifiers include alkali metal or
alkaline earth metal salts of organic acids such as magnesium
sulfonate, zinc sulfonate, magnesium phenate, zinc phenate, lithium
sulfonate, lithium carboxylate, lithium salicylate, lithium
phenate, sulfurized lithium phenate, magnesium sulfonate, magnesium
carboxylate, magnesium salicylate, magnesium phenate, sulfurized
magnesium phenate, potassium sulfonate, potassium carboxylate,
potassium salicylate, potassium phenate, sulfurized potassium
phenate; common acids such as alkylbenzenesulfonic acids,
alkylphenols, fatty carboxylic acids, polyamine, polyhydric alcohol
derived polyisobutylene derivatives.
[0045] Examples of defoamants include polysiloxanes, polyacrylates
and styrene ester polymers.
[0046] Examples of compatibilizers include aromatic hydrocarbons
such as 1-methyl-naphthalene, aromatic ethers such as diphenyl
ether or anisole (methyl phenyl ether), long chain alcohols such as
nonyl phenol, octanol and decanol.
[0047] Examples of dispersants include alkenylsuccinimide such as
polyisobutylene succinimide, N-substituted polyisobutenyl
succinimides such as polyisobutenyl
succinimide-polyethylenepolyamine, succinates, succinate esters,
alkyl methacrylate-vinyl pyrrolidinone copolymers, alkyl
methacrylate-dialkylaminoethyl methacrylate copolymers,
alkylmethacrylate-polyethylene glycol methacrylate copolymers,
polystearamides, high molecular weight amines, phosphoric acid
derivatives such as bis-hydroxypropyl phosphorate.
[0048] Some additives may possess multiple properties and provide
for a multiplicity of affects. For example, graphite and molybdenum
disulfide may both be used as friction modifiers and extreme
pressure additives or functionalized soaps may be used to thicken
but also provide extreme pressure and antiwear performances for
greases. This approach is well known by the person skilled in the
art and need not be further elaborated herein.
[0049] An additive may be used alone or in combination with other
additives.
[0050] When present in the lubricant composition of the invention,
the sole or multiple additive(s) may be used at a level of from 0
to 10 wt %, alternatively 0.1 to 5 wt %, based on the total weight
of the lubricant composition. Thickeners to produce greases may be
used at a level of from 1, to 55% wt, alternatively 1 to 45% wt,
alternatively 3 to 30% wt based on the total weight of the
lubricant grease composition as discussed above.
[0051] Hence, a lubricant comprising the copolymer as described
above may comprise: 0 to 10 weight % of one or more additives and
90 to 100 weight % of copolymer; alternatively from 0.1 to 10
weight % of one or more additives and 90 to 99.9 weight % of
copolymer or further alternatively 0.1 to 5% by weight additive and
99.9 to 95% of copolymer (in each case the sum total being 100
weight %).
[0052] In the case of a lubricant grease composition the
composition may comprise: 0 to 10 weight % of one or more additives
(excluding thickeners),
1 to 55% wt of thickeners and the remainder of the composition
being copolymer as hereinbefore described; Alternatively the
composition may comprise: 0 to 10 weight % of one or more additives
(excluding thickeners), 1 to 50% wt of thickeners and the remainder
of the composition being copolymer as hereinbefore described;
alternatively, a lubricant grease composition the composition may
comprise: 0 to 10 wt % of one or more additives (excluding
thickeners), 3 to 30 weight % of thickeners and the remainder of
the composition being copolymer as hereinbefore described.
Alternatively a lubricant grease composition the composition may
comprise: 0.1 to 5 weight % of one or more additives (excluding
thickeners) 3 to 30 weight % of thickeners and the remainder of the
composition being copolymer as hereinbefore described.
Alternatively the composition may be any combination of the
ingredients discussed above with the total composition being 100
weight %.
[0053] Typically the Viscosity Index of the copolymer and/or
lubricant containing a copolymer as described above has a value of
at least 125, alternatively at least 150 as measured in accordance
with ASTM D 2270-10e1.
[0054] Operating temperatures for the use of the lubricant
composition, meaning the temperatures at which the lubricant
composition may be used for prolonged time (also called service
temperatures), range of from -55.degree. C. to +250.degree. C.
Short term peak temperatures may be higher.
[0055] The above relative amounts of ingredients in compositions
are intended to relate to all embodiments and possible combinations
thereof described above.
[0056] The copolymers show improved heat stability versus pure
MTFPS and surprisingly better lubricating properties such as load
carrying capacity and wear (as discussed in the following examples)
than either PMPS or MTFPS.
[0057] Lubricating compositions may be used in a variety of
applications where friction occurs between rubbing surfaces. The
surfaces may be plastic or metal.
[0058] The present invention includes a method to lubricate
metal-metal surfaces comprising: [0059] i. obtaining a lubricant
composition comprising the composition as hereinbefore described
and; [0060] ii. lubricating the metal-metal surface with said
lubricant composition.
[0061] The present lubricant composition may be used in any system
that includes machine elements that contain gears of any kind and
roller bearings. Examples of such systems include electricity
generating systems, industrial manufacturing equipments such as
paper, steel and cement mills hydraulic systems, automotive drive
trains, aircraft propulsion systems, etc.
[0062] Further systems include crankcases, internal combustion
engines such as 2-stroke engines, 4-stroke engines, diesel engines,
gears for manual or differential transmission systems, traction and
torque systems.
[0063] The lubricant composition may be used as industrial
lubricants, hydraulic fluids, heat transfer fluids, compressor oils
or fluids, turbine oils, metal working fluids, metal forming
lubricant, lubrication grease, as an automatic transmission fluid,
a manual transmission fluid, sliding contact bearings lubricant,
lubricant for chains, an axle lubricant, a transaxle lubricant, an
industrial gear lubricant, a circulating lubricant, a gear oil for
wind turbines, an open gear lubricant and/or an enclosed gear
lubricant.
[0064] The fluids are furthermore of interest as antifoams,
especially for oil and gas applications, and potentially as
plasticizers in silicone elastomers
[0065] The disclosure will now be described by way of Example.
Viscosity values given throughout this document are either shown as
dynamic viscosity values in mPas measured with a rotational
viscometer Rheoplus from Anton Paar or as kinematic viscosity
values in cSt (mm.sup.2s.sup.-1) measured with a capillary
viscometer according to ASTM D445-06. All viscosity measurements
were taken at room temperature (approximately 20.degree. C.) unless
otherwise indicated.
EXAMPLE 1
Preparation of the Co-Polymer
[0066] A variety of co-polymers were prepared using the process as
hereinbefore described. The resulting products were used in a
variety of test described in detail below.
[0067] a.) 100.12 g of a trimethylsilyl terminated
polymethylphenylsiloxane having a viscosity of 500 cst (500
mm.sup.2s.sup.-1), 114.54 g trimethylsilyl terminated
methyltrifluoropropylsiloxane having a viscosity of 300 cst (300
mm.sup.2s.sup.-1) and 0.97 g KOH (1N) were added to a flask. The
mixture was heated to 140.degree. C. under vigorous stirring. A
white dispersion is formed. The mixture is kept at 140.degree. C.
for one hour under a nitrogen stream. The mixture became clear
after approx. 20 minutes. The mixture is then cooled down and dry
ice is added to neutralize the KOH. A clear liquid having a
viscosity of 80 mPas at 40.degree. C. was obtained. Si-NMR
confirmed that a copolymer was formed during the reaction.
[0068] b.) 151.51 g a trimethylsilyl terminated
polymethylphenylsiloxane having a viscosity of 500 cst (500
mm.sup.2s.sup.-1), 521 g trimethylsilyl terminated
methyltrifluoropropylsiloxane having a viscosity of 300 cst (300
mm.sup.2s.sup.-1) and 3.05 g KOH (1N) were added to a flask. The
mixture was heated to 140.degree. C. under vigorous stirring. A
white dispersion is formed. The mixture is kept at 140.degree. C.
for one 30 minutes under a nitrogen stream. The mixture became
clear after approx. 20 minutes. The mixture is then cooled down and
dry ice is added to neutralize the KOH. A clear liquid having a
viscosity of 67 mPas at 40.degree. C. was obtained.
[0069] c.) 450.04 g a trimethylsilyl terminated
polymethylphenylsiloxane having a viscosity of 500 cst (500
mm.sup.2s.sup.-1), 172.72 g trimethylsilyl terminated
methyltrifluoropropylsiloxane having a viscosity of 300 cst (300
mm.sup.2s.sup.-1) and 3.07 g KOH (1N) were added to a flask. The
mixture was heated to 140.degree. C. under vigorous stirring. A
white dispersion is formed. The mixture is kept at 140.degree. C.
for one hour under a nitrogen stream. The mixture became clear
after approx. 20 minutes. The mixture is then cooled down and dry
ice is added to neutralize the KOH. A clear liquid having a
viscosity of 109 mPas at 40.degree. C. was obtained.
[0070] d.) 303.02 g a trimethylsilyl terminated
polymethylphenylsiloxane having a viscosity of 500 cst (500
mm.sup.2s.sup.-1), 332.29 g trimethylsilyl terminated
methyltrifluoropropylsiloxane having a viscosity of 1000 cst (1000
mm.sup.2s.sup.-1) and 3.05 g KOH (1N) were added to a flask. The
mixture was heated to 140.degree. C. under vigorous stirring. A
white dispersion is formed. The mixture is kept at 140.degree. C.
for one hour under a nitrogen stream. The mixture became clear
after approx. 20 minutes. The mixture is then cooled down and dry
ice is added to neutralize the KOH. A clear liquid having a
viscosity of 90 mPas at 40.degree. C. was obtained.
[0071] e.) The preparation utilized in example 1b above was
repeated. However in this case once the crude product was obtained,
volatiles were removed by using a wiped film evaporator (Pope
Scientific Inc of Saukville, Wis.) at 200.degree. C./66.66 Pa (0.5
mmHg). A clear liquid was obtained that had a viscosity of 298 mPas
at 40.degree. C.
[0072] f.) The preparation utilized in example 1a above was
repeated. However in this case once the crude product was obtained,
volatiles were removed by using a wiped film evaporator (Pope
Scientific Inc of Saukville, Wis.) at 200.degree. C./66.66 Pa (0.5
mmHg). A clear liquid was obtained that had a viscosity of 308 mPas
at 40.degree. C.
[0073] g.) The preparation utilized in example 1c above was
repeated. However, in this case once the crude product was
obtained, volatiles were removed by using a wiped film evaporator
(Pope Scientific Inc of Saukville, Wis.) at 200.degree. C./66.66 Pa
(0.5 mmHg). A clear liquid was obtained that had a viscosity of 391
mPas at 40.degree. C.
EXAMPLE 2
[0074] The Oxidation stability of the copolymers produced via
methods 1 b, 1c and 1d in Example 1 were tested. The test were
undertaken using differential scanning calorimetry (DSC) with the
oxidative onset temperature at a heating rate of 10.degree. C./min
under an air flow of 60 ml/min. Load carrying capacity (LCC) was
also tested on the samples of the same copolymers using ASTM
D5706-05 with a cylinder on plate geometry at a reduced oscillating
frequency of 10 Hz. The LCC is expressed in OK load presenting the
step (increased in 50N increments every 2 min) load where friction
was stable.
[0075] The following table shows a comparison between the
copolymeric products produced in example 1 from methods 1 b, 1c and
1d, trimethylsilyl terminated polydimethylsiloxane having a
viscosity of 50 cSt (500 mm.sup.2s.sup.-1), and the starting
materials from Example 1a, 1 b and 1c, trimethylsilyl terminated
polymethylphenylsiloxane having a viscosity of 500 cSt (500
mm.sup.2s.sup.-1) and trimethylsilyl terminated
methyltrifluoropropylsiloxane having a viscosity of 300 cSt (500
mm.sup.2s.sup.-1).
TABLE-US-00001 TABLE 1 Oxidation onset (.degree. C.) (differential
scanning Ok load Material calorimetry (DSC)) (N) (LCC) Example 1b
299 1650 Example 1c 339 1800 Example 1d 266 800 trimethylsilyl
terminated 246 550 methyltrifluoropropylsiloxane trimethylsilyl
terminated 300 300 polydimethylsiloxane trimethylsilyl terminated
376 150 polymethylphenylsiloxane
[0076] The table shows that the copolymer has improved load
carrying versus the homopolymers and a better oxidation stability
than the trimethylsilyl terminated methyltrifluoropropylsiloxane
and even polydimethylsiloxane.
EXAMPLE 3
[0077] Four ball wear scars were determined for the products of the
methods described in examples 1e, 1f and 1g in combination with a
variety of standard additives in lubricant compositions as
indicated in Table 2 below.
[0078] Wear properties or lubrication performance may be evaluated
by standard test method DIN 51350-3 `Testing of lubricants in the
Shell four-ball tester`. The Shell Four Ball Tester (FBT) is a
testing device used to determine welding and metal loads as well as
different friction and wear characteristics of lubricants. The
standard test consists of a rotating ball bearing being pressed
onto three similar but immobile balls while applying a load of 100
N, 400 N and 800 N for 1 hour test duration. Wear is determined by
optically measuring the formed calotte (the worn depression
area).
[0079] This testing device is especially common in the lubricant
industry where it is used for routine product development and
quality control testing. The friction torque can be recorded
continuously.
[0080] In this instance the testing was done according to DIN
51350-3 and the wear scar is reported as the average of the three
steel balls in mm after applying a load of 400N and 800N for 1 hour
test duration (i.e. no 100N test undertaken). The results can be
seen in Table 2 below:
TABLE-US-00002 TABLE 2 Wear Wear scar (mm) scar (mm) Copolymer
Additive at 400 N at 800 N Example 1 e -- 0.55 1.81 Example 1 e 1%
VL622 0.51 0.71 Example 1 e 2.5% VL 622 0.68 1.00 Example 1 e 2.5%
VL AZ 0.72 1.32 Example 1f -- 1.78 2.5 Example 1f 2.5% VL 622 0.55
1.03 Example 1f 2.5% VL AZ 0.51 1.07 Example 1g -- 1.53 Not
measurable Example 1g 2.5% VL 622 2.20 2.38 Example 1g 4% Anglamol
0.90 1.47 99 trimethylsilyl terminated -- 1.18 1.17
methyltrifluoropropylsiloxane trimethylsilyl terminated -- Not Not
polymethylphenylsiloxane measur- measurable able Comparative PAO 6
4% Anglamol 0.71 1.34 99 Comparative PFPE Y25 -- 1.01 1.58
PAO 6 is a commercial polyalphaolefin named PAO SpectraSyn.TM. 6
from ExxonMobil Chemicals. PFPE Y25 is a commercial
perfluoropolyether named Fomblin.RTM. Y25 from Solvay. VL 622 and
VL AZ are commercial additives named Vanlube 622 and Vanlube AZ
from R.T. Vanderbilt. Anglamol 99 is a commercial additive named
Anglamol.RTM. 99 from Lubrizol.
EXAMPLE 4
[0081] In this Example a cyclic methyltrifluoropropylsiloxane with
n=3 is utilised in combination with two different
polymethylphenylsiloxanes to prepare the copolymer, using the same
method as discussed in Example 1.
[0082] 26.78 g of a trimethylsilyl terminated
polymethylphenylsiloxane having a viscosity of 500 cst, (500
mm.sup.2s.sup.-1), 154.88 g of a hydroxydimethylsilyl terminated
polymethylphenylsiloxane having a viscosity of 500 cst, (500
mm.sup.2s.sup.-1). 68.37 g of a methyltrifluoropropylsiloxane
cyclotrisiloxane and 0.18 g KOH were added to a flask. The mixture
was heated to 140.degree. C. under vigorous stirring. A white
dispersion is formed initially. The mixture is kept at 140.degree.
C. for one hour under a nitrogen sweep. The mixture became clear
after approx. 30 minutes. The mixture is then cooled down and dry
ice is added to neutralize the KOH. Volatiles are removed from the
product by using a wiped film evaporator (Pope Scientific Inc of
Saukville, Wis.) at 200.degree. C./66.66 Pa (0.5 mmHg). A clear
liquid having a viscosity of 20,300 mPas at 20.degree. C. was
obtained. Si-NMR confirmed that a copolymer was formed during the
reaction. The resulting product had a wear scar of 1.5 mm at 400N
and an oxidation onset of 475.degree. C. using the methods
described above in Examples 2 and 3.
* * * * *