U.S. patent application number 11/579617 was filed with the patent office on 2008-05-08 for silicone grease with high cold cohesion.
Invention is credited to Pierre Belot, Michel Feder, Sebastien Lanau.
Application Number | 20080108530 11/579617 |
Document ID | / |
Family ID | 34944693 |
Filed Date | 2008-05-08 |
United States Patent
Application |
20080108530 |
Kind Code |
A1 |
Feder; Michel ; et
al. |
May 8, 2008 |
Silicone Grease with High Cold Cohesion
Abstract
Silicone grease with high cold cohesion, characterized in that
it comprises at least one oily diorganopolysiloxane polymer, 10% to
30% by weight of organometallic soap(s) and 5% to 20% by weight of
chloroparaffin(s). Use of said grease as a treating and/or
protecting and/or lubricating agent in the field of moving metallic
mobile components, with good cohesion, especially when cold, thus
making it possible to avoid, inter alia, skating phenomena,
especially when cold, between components involved in a drive
device.
Inventors: |
Feder; Michel;
(Villeurbanne, FR) ; Lanau; Sebastien; (Saronno,
IT) ; Belot; Pierre; (Eugies, BE) |
Correspondence
Address: |
BUCHANAN, INGERSOLL & ROONEY PC
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Family ID: |
34944693 |
Appl. No.: |
11/579617 |
Filed: |
April 19, 2005 |
PCT Filed: |
April 19, 2005 |
PCT NO: |
PCT/FR05/00943 |
371 Date: |
November 14, 2007 |
Current U.S.
Class: |
508/208 |
Current CPC
Class: |
C10M 2211/022 20130101;
C10N 2010/04 20130101; C10M 169/02 20130101; C10M 2207/1265
20130101; C10M 2229/0425 20130101; C10N 2010/14 20130101; C10N
2050/10 20130101; C10N 2010/08 20130101; C10M 2229/0415 20130101;
C10N 2040/08 20130101; C10M 169/00 20130101; C10M 2207/1285
20130101; C10N 2040/04 20130101; C10N 2010/02 20130101; C10M
2211/0225 20130101 |
Class at
Publication: |
508/208 |
International
Class: |
C10M 169/04 20060101
C10M169/04 |
Foreign Application Data
Date |
Code |
Application Number |
May 5, 2004 |
FR |
0404793 |
Claims
1.-10. (canceled)
11. A high cold cohesion silicone grease comprising at least one
oily diorganopolysiloxane polymer, 10% to 30% (weight percentage
expressed relative to the weight of the grease) of organometallic
soap(s) and 5% to 20% by weight of halogenated paraffin(s), said
grease comprising chloroparaffins consisting essentially of
petroleum distillation-based linear hydrocarbons that have been
chlorinated, belonging to one and/or other of the following three
categories: C10-C13 short chain chloroparaffins, C14-C17
medium-chain chloroparaffins and C18-C30 long-chain
chloroparaffins, each of the abovementioned categories optionally
having a weight percentage of chlorine in the range from 30% to
70%.
12. The grease as claimed in claim 11, wherein the C14-C17
medium-chain and C18-C30 long-chain chloroparaffins have a weight
percentage of chlorine in the range from 40% to 60%.
13. The grease as claimed in claim 11, further comprising a high
flow threshold, of greater than 600 Pa at -40.degree. C.
14. The grease as claimed in claim 11, further comprising 1% to 8%
by weight of auxiliary additive(s).
15. The grease as claimed in claim 11, wherein the oily
diorganopolysiloxane polymers correspond to the general formula:
(R).sub.3SiO[Si(R).sub.2O].sub.nSi(R).sub.3 in which the symbols R,
which may be identical or different, represent hydrocarbon-based
radicals free of aliphatic unsaturations and containing up to 13
carbon atoms, and the symbol n represents any number from 30 to
1500.
16. The grease as claimed in claim 11, wherein the organometallic
soaps are derived from higher fatty acids containing from 10 to 32
carbon atoms and from metallic Li, Na, K, Cs, Mg, Ca, Sr, Cd, Zn,
Pb and Co compounds.
17. The grease as claimed in claim 11, further comprising
nonhydrolated organometallic soaps derived from nonhydroxylated
fatty acids.
18. A process for preparing a high cold cohesion silicone grease,
wherein the grease comprises at least one oily diorganopolysiloxane
polymer, 10% to 30% (weight percentage expressed relative to the
weight of the grease) of organometallic soap(s) and 5% to 20% by
weight of halogenated paraffin(s), said grease comprising
chloroparaffins consisting essentially of petroleum
distillation-based linear hydrocarbons that have been chlorinated,
belonging to one and/or other of the following three categories:
C10-C13 short chain chloroparaffins, C14-C17 medium-chain
chloroparaffins and C18-C30 long-chain chloroparaffins, each of the
abovementioned categories optionally having a weight percentage of
chlorine in the range from 30% to 70%, the process comprising
melting/recrystallizing the soap in the oily diorganopolysiloxane
polymer(s); and incorporating the halogenated paraffin(s) either
before or after the melting/recrystallization step.
19. A method of treating and/or protecting or lubricating a
metallic component, the method comprising applying an amount of a
high cold cohesion silicone grease to the metallic component,
wherein the high cold cohesion silicone grease comprises at least
one oily diorganopolysiloxane polymer, 10% to 30% (weight
percentage expressed relative to the weight of the grease) of
organometallic soap(s) and 5% to 20% by weight of halogenated
paraffin(s), said grease comprising chloroparaffins consisting
essentially of petroleum distillation-based linear hydrocarbons
that have been chlorinated, belonging to one and/or other of the
following three categories: C10-C13 short chain chloroparaffins,
C14-C17 medium-chain chloroparaffins and C18-C30 long-chain
chloroparaffins, each of the abovementioned categories optionally
having a weight percentage of chlorine in the range from 30% to 70%
and wherein the grease exhibits a high flow threshold, of greater
than 600 Pa at -40.degree. C.
20. The method of claim 19, wherein the metallic component is a
component used in the motor vehicle field.
21. The method of claim 20, wherein the component is used in a
drive device comprising a vehicle clutch cable, a gearbox or a
starter.
Description
[0001] The present invention relates to organometallic-soap-based
silicone greases with high cohesion, in particular when cold. The
invention also relates to the process for preparing said greases
and to their use especially in the motor vehicle industry.
[0002] It is known that certain applications in the motor vehicle
industry require the application of greases that are highly
cohesive, in particular when cold, in order to avoid: [0003]
firstly, skating phenomena between mobile metallic components that
are involved in a drive device, and [0004] secondly, possible
losses of grease by flow thereof from its housing in the case of an
application in which the grease is in an unconfined chamber.
[0005] Examples of drive devices that will be mentioned include: a
motor vehicle clutch cable, gearbox or starter.
[0006] It has been possible to establish in this field of the art a
correlation between the behavior in mechanical tests reproducing
skating phenomena between components involved in a drive device,
and the flow threshold value of grease (or critical stress), such
that avoidance of the abovementioned phenomena proceeds via
improving the value of the cold threshold; in a manner that is
known per se, the flow threshold may be measured, for example,
using a controlled-stress rheometer capable of conditioning the
grease at the temperature chosen for the test (in this case
-40.degree. C.).
[0007] The essential objective of the present invention is to
propose a silicone grease that can have a high flow threshold, of
greater than 600 Pa at -40.degree. C.
[0008] Another objective is that of proposing a silicone grease
that can have such a high cold flow threshold, without impairing
the standard properties of the grease, in particular its
consistency at an ambient temperature of 23.degree. C., its low
content of volatiles and good resistance to exudation (or bleeding)
when hot, i.e. at a temperature in the range from 100.degree. C. to
170.degree. C.
[0009] Yet another objective is that of proposing such silicone
greases that can be prepared via a process known to those skilled
in the art and under economical cost price conditions.
[0010] One subject of the present invention is thus a high cohesion
silicone grease comprising at least one oily diorganopolysiloxane
polymer, 10% to 30% (weight percentage expressed relative to the
weight of the grease) of organometallic soap(s) and 5% to 20% by
weight of halogenated paraffin(s), said grease being characterized
in that chloroparaffins are used consisting essentially of
petroleum distillation-based linear hydrocarbons that have been
chlorinated, belonging to one and/or other of the following three
categories: C10-C13 short-chain chloroparaffins, C14-C17
medium-chain chloroparaffins and C18-C30 long-chain
chloroparaffins, each of the abovementioned categories possibly
having a weight percentage of chlorine in the range from 30% to
70%.
[0011] The oily diorganopolysiloxane polymers, which are the basic
constituents of the greases, correspond to the general formula:
(R).sub.3SiO[Si(R).sub.2O].sub.nSi(R).sub.3
in which the symbols R, which may be identical or different,
represent hydrocarbon-based radicals free of aliphatic
unsaturations and containing up to 13 carbon atoms, and the symbol
n represents any number ranging from 30 to 1500.
[0012] These linear polymers thus consist essentially, besides the
end units, of a succession of units of formula (R).sub.2SiO;
however, the presence of a small amount of other units, such as
those of formulae SiO.sub.2 and (R)SiO.sub.1.5, is not excluded in
a proportion of up to 1% relative to the number of (R).sub.2SiO
units.
[0013] The hydrocarbon-based radicals represented by the symbols R
are chosen from: [0014] alkyl radicals containing from 1 to 13
carbon atoms, especially such as methyl, ethyl, propyl, butyl,
pentyl, hexyl, 2-ethylhexyl, octyl, decyl and dodecyl radicals;
[0015] aromatic radicals with only one benzene nucleus containing
from 6 to 10 carbon atoms, especially such as phenyl, tolyl, xylyl,
ethylphenyl, cumenyl and butylphenyl radicals, these radicals
possibly bearing one or more substituents comprising chlorine.
[0016] However, for each molecule of the polymers, at least 45% in
numerical terms of all of the hydrocarbon-based radicals R are
alkyl radicals. These diorganopolysiloxane polymers are oily
liquids whose viscosities range (according to the nature of the
radicals R and the values of n) substantially from 100 mPa.s to 500
000 mPa.s at 25.degree. C. They are mostly industrially
manufactured by silicone manufacturers; moreover, their preparation
is given in the chemical literature, for example in French patents
978 058,1 025 150 and 1 108 964.
[0017] As a guide for the polymers that may be used, mention may be
made of those represented by the following formulae:
(CH.sub.3).sub.3SiO [Si(CH.sub.3).sub.2O].sub.n1 Si(CH.sub.3).sub.3
(I) [0018] n1=50 to 1500
[0018] (CH.sub.3).sub.3SiO [Si(CH.sub.3).sub.2O].sub.n2
[Si(C.sub.2H.sub.5)(CH.sub.3)O].sub.n'2 Si(CH.sub.3).sub.3 (II)
[0019] n2=30 to 1000 [0020] n'2=10 to 200
[0020] (CH.sub.3).sub.3SiO [Si(CH.sub.3).sub.2O].sub.n3
[Si(nC.sub.8H.sub.17)(CH.sub.3)O].sub.n'3 Si(CH.sub.3).sub.3 (III)
[0021] n3=25 to 800 [0022] n'3=10 to 150
[0022] (CH.sub.3).sub.3SiO [Si(CH.sub.3).sub.2O].sub.n4
[Si(nC.sub.12H.sub.25)(CH.sub.3)O].sub.n'4 Si(CH.sub.3).sub.3 (IV)
[0023] n4=25 to 800 [0024] n'4=10 to 150
[0024] (CH.sub.3).sub.3SiO [Si(CH.sub.3).sub.2O].sub.n5
[Si(C.sub.6H.sub.5)(CH.sub.3)O].sub.n'5 Si(CH.sub.3).sub.3 (V)
[0025] n5=25 to 600 [0026] n'5=5 to 130
[0026] (CH.sub.3).sub.3SiO [Si(CH.sub.3).sub.2O].sub.n6
[Si(C.sub.6H.sub.5).sub.2O].sub.n'6 Si(CH.sub.3).sub.3 (VI) [0027]
n6=25 to 600 [0028] n'6=5 to 100
[0028] (CH.sub.3).sub.3SiO [Si(CH.sub.3).sub.2O].sub.n7
[Si(C.sub.6H.sub.2Cl.sub.3)(CH.sub.3)O].sub.n'7 Si(CH.sub.3).sub.3
(VII) [0029] n7=25 to 600 [0030] n'7=5 to 100
[0031] The values of ni and of n'i (i=1 to 7) vary, respectively,
within the given ranges, such that the number of methyl radicals in
each polymer molecule represents, as already indicated, at least
45% in numerical terms of all of the radicals attached to the
silicon atoms of these polymers.
[0032] The oily diorganopolysiloxane polymers preferably used,
alone or as a mixture, are those represented by formulae (III) to
(VII).
[0033] Besides the oily diorganopolysiloxane polymers, the silicone
greases according to the invention contain, as gelling agent,
organometallic soaps.
[0034] The gelling agents used to form the grease may be fatty acid
soaps. The saponifiable matter may be derived from higher fatty
acids containing from 10 to 32 carbon atoms, these acids possibly
being hydroxylated or nonhydroxylated and possibly being saturated
or unsaturated.
[0035] Soaps of nonhydroxylated fatty acids are preferably used,
especially such as: capric acid, lauric acid, myristic acid,
palmitic acid, stearic acid, arachidic acid, behenic acid,
lignoceric acid, myristoleic acid, palmitoleic acid, oleic acid,
linoleic acid and erucic acid; fatty acids from cottonseed oil,
palm oil and hydrogenated fish oil, optionally as a mixture, and/or
glycerides thereof, for instance lard oil, beef oil, rapeseed oil,
palm oil, menhaden oil or herring oil; acids derived from the
oxidation of liquid petroleum and of waxes; resinous acids;
heavy-oil acids; abietic acids; naphthenic acids; sulfonic
acids.
[0036] The saponification agent used to make the soap may be a
metallic Li, Na, K, Cs, Mg, Ca, Sr, Cd, Zn, Pb or Co compound and
preferably an oxide, a hydroxide or a carbonate of one of the
abovementioned alkali metals and alkaline-earth metals. Mixtures of
soaps may also be used, and these soaps may be either prepared in
situ or manufactured beforehand to form the grease.
[0037] Particular examples of soaps used alone or as mixtures are:
the lithium soap of stearic acid; the lithium soaps of hydrogenated
fish oil fatty acids; the sodium soap of stearic acid; the sodium
soap of oleic acid; the potassium soap of oleic acid; the calcium
soap of stearic acid; the barium soap of stearic acid; the barium
soaps of mixed stearic and oleic acids; the composite lithium and
sodium soaps of stearic acid.
[0038] The soaps that are especially suitable, used alone or as a
mixture, are the lithium soap of stearic acid and the composite
lithium and sodium soaps of stearic acid.
[0039] The soap content of the greases according to the present
invention represents 10% to 30% by weight; it is recommended for
this content to represent from 15% to 25% by weight.
[0040] Moreover, auxiliary additives, the aim of which is to
facilitate the preparation of the greases (better dispersion of the
charges, reduction of the blending time) and/or to improve their
internal cohesion and/or to provide a coloration, may be
incorporated with the oily diorganopolysiloxane polymers and the
organometallic soaps. Additives that may be mentioned, as a guide,
include: polyalkylene glycols; boric acid and alkyl borates;
pentaerythritol; hydroxylated diorganopolysiloxane oils with a low
viscosity ranging from 10 to 500 mPa.s at 25.degree. C.; colored
pigments. The total amount of these additives introduced, when they
are used, is in the range generally from 1% to 8% by weight
relative to the weight of the grease.
[0041] The chloroparaffins included in the constitution of the
silicone greases according to the present invention may be chosen
from many described and marketed organic compounds of this
type.
[0042] It is known that such compounds are liquid at atmospheric
pressure and at room temperature (23.degree. C.); they have a
viscosity in the range from 500 to 100 000 mPa.s, preferably
ranging from 1000 to 20 000 mPa.s.
[0043] The Applicant has found that, under the conditions of the
invention, the chloroparaffins used are preferably C14-C17
medium-chain and C18-C30 long-chain chloroparaffins with a weight
percentage of chlorine in the range from 40% to 60%.
[0044] As specific examples of chloroparaffins that are especially
suitable, mention may be made especially of the products sold by
the company Ineos Chlor under the trade names: S54, S56, E56, M50,
42SS and 48.
[0045] The content of chloroparaffin(s) in the greases according to
the present invention represents 5% to 20% by weight; it is
recommended for this content to represent from 10% to 15% by
weight.
[0046] The greases are prepared by melting/recrystallization of the
soap in the oily diorganopolysiloxane polymer(s) and by
incorporating the chloroparaffin(s) either before or after the
melting/recrystallization step, but preferably after the step of
melting/recrystallization and cooling of the grease. This procedure
is performed in devices designed for the blending of viscous
mixtures; thus, for example, blenders and mills are particularly
suitable for this preparation. In a subsequent step, it is
possible, if necessary, to mill the grease, for example working in
a roll mill or in a colloidal mill, to adapt the rheology and/or
the appearance of the grease to the desired applications.
[0047] The greases according to the present invention may have a
high flow threshold, of greater than 600 Pa at -40.degree. C.,
while at the same time affording desirable characteristics in
terms, for example, of penetration, content of volatile compounds
and exudation behavior.
[0048] These greases are successfully used as treating and/or
protecting and/or lubricating agents in the field of moving
metallic mobile components; since they have good cohesion,
especially when cold, they consequently make it possible to avoid,
inter alia, skating phenomena, especially when cold, between
components involved in a drive device, for instance the components
involved, in the motor vehicle field, in: a vehicle clutch cable,
gearbox or starter.
[0049] The examples that follow illustrate the invention.
EXAMPLE 1
1. The Preparation of a Silicone Grease According to the Invention
is Illustrated Below
[0050] The formulation of this grease is given in table 1
below.
TABLE-US-00001 TABLE 1 Ingredients/Procedure Control Example 1
Premix 35/65 (weight %) (1) 64 64 Oil 510V100 (%) (2) 36 24
Chloroparaffin (%) (3) 0 12 Soap content by mass of the grease (%)
22.4 22.4 Chloroparaffin content by mass of the grease (%) 0 12
Blending time in a Speed-mixer 2 min 20 s 2 min 20 s (1) Premix
35/65: mixture consisting of 35% by weight of lithium stearate and
65% by weight of oil 510V100; this mixture is obtained by working
in an arm blender; it has undergone a melting/recrystallization
cycle under the following conditions: melting of the soap at about
200.degree. C. followed by cooling to 23.degree. C.; (2) Oil
510V100: poly(dimethyl)(methylphenyl)siloxane copolymer with a
viscosity of 100 mPa.s at 25.degree. C. and comprising 15% by
weight of Si(C.sub.6H.sub.5)(CH.sub.3)O units; (3) Chloroparaffin:
product sold by the company Ineos Chlor under the trade name E56,
having the following characteristics: C14-C17 chains; viscosity at
25.degree. C.: 11 868 mPa.s; molar mass: 459.6 g; weight % of
Cl.sub.2: 55.75.
[0051] The greases were prepared with a DAC 150FV-K Speed-mixer.TM.
blender (sold by the company Hauschild Engineering), starting with
a grease premix composed of 35% by weight of lithium stearate and
65% by weight of oil H510V100. The chloroparaffin additive is added
and the oil H510V100 completes the formulation so as to give a
final lithium stearate content of 22.4% by weight and a final
chloroparaffin content of 12% by weight.
2. The General Properties of the Grease Prepared According to
Paragraph 1 are Given Below
TABLE-US-00002 [0052] TABLE 2 Properties Control Example Flow
threshold at -40.degree. C. in Pa (4) 300 850 Worked penetration
(1/10 mm) (5) 260-300 263 % volatiles (6) <3 1.79 Exudation (7)
<4 0.91 (4) Flow threshold: Apparatus used: Rheometric
scientific SR5 controlled-stress rheometer; Julabo F25 thermostatic
bath; 25 mm cone/plate, angle of 0.0984 rad.: + Gap: 0.0559 mm, +
Serial number 4144. Procedure: 1) The plate is cooled to
-40.degree. C. by means of circulation of an ethanol-based fluid
maintained at -40.degree. C. by means of the combined use of a
cooling bath and cardice; 2) The apparatus is zeroed and, once the
gap has been adjusted, the inertia of the empty spindle is checked
until it is a constant value; 3) The condensation that appears on
the plate is removed with acetone; 4) The product is inserted and
the gap is then adjusted; 5) The analysis is chosen: scanning in
dynamic stress mode from 1 to 5000 Pa at a set frequency of 6.28
rad/s; 6) Once the plate has stabilized at -40.degree. C., the
analysis is started; 7) Each sample is analyzed twice in order to
check the repeatability of the measurement. It may be pointed out
that the analysis is performed at -40.degree. C. at a frequency of
1 Hz. This appears to be correlated to a frequency of about 3000
rpm at ambient temperature. (5) Worked penetration: the consistency
of the grease, sheared in a specific tool, is evaluated by
measuring the penetration of a cone into the grease under the
conditions defined in standard NF T 60132 (equivalent to ASTM
standard D 217); (6) % volatiles: by working on 10 g of grease, the
weight loss of the grease placed in an oven at 150.degree. C. for
24 hours is measured; (7) exudation: by working according to the
conditions of standard FTMS 791321, the amount of oil exuded
through a metal grille, onto which have been placed 10 g of grease
maintained at 150.degree. C. for 24 hours, is measured.
3. The Performance of the Grease Prepared According to Paragraph 1
in the Motor Vehicle Field is Presented Below
[0053] The mechanical tests, performed with the grease prepared
according to paragraph 1, on several drive configurations and on
several starters, are positive: absence of skating at -40.degree.
C. and correct functioning of the starters when hot, on test
benches.
[0054] It should be pointed out that, in this application, the
grease is introduced into the coupling and uncoupling device
connecting the starter itself to the combustion engine of a motor
vehicle.
EXAMPLES 2 TO 5
[0055] The preparation of other silicone greases according to the
invention is illustrated below:
[0056] These greases: [0057] were prepared according to the same
protocol as that described in example 1, part 1, but with other
chloroparaffins used in proportions of which some have been
modified (cf. table 3 below), and [0058] give the following
properties (cf. table 3 below):
TABLE-US-00003 [0058] TABLE 3 Control EX 2 EX 3 EX 4 EX 5
Compositions Chloroparaffin -- S54 (8) S56 (9) M50 (10) 42SS (11)
weight % in the -- 10 10 15 15 grease Properties Flow threshold (4)
300 850 850 1000 1000 Penetration (5) 260-300 283 275 269 260 %
volatiles (6) <3 1.52 1.43 1.64 1.76 Exudation (7) <4 1.06
0.94 0.48 0.89 (8): product sold by the company Ineos Chlor under
the name S54, having the following characteristics: C14-C17 chains;
viscosity at 25.degree. C.: 4400 mPa s; molar mass: 443.2 g; weight
% of Cl.sub.2: 54; (9): product sold by the company Ineos Chlor
under the name S56, having the following characteristics: C14-C17
chains; viscosity at 25.degree. C.: 11 868 mPa s; molar mass: 459.6
g; weight % of Cl.sub.2: 55.75; (10): product sold by the company
Ineos Chlor under the name M50, having the following
characteristics: C18-C20 chains; viscosity at 25.degree. C.: 17 700
mPa s; molar mass: 520.3 g; weight % of Cl.sub.2: 52.2; (11):
product sold by the company Ineos Chlor under the name 42SS, having
the following characteristics: waxy chains; viscosity at 25.degree.
C.: 2160 mPa s; molar mass: 625.1 g; weight % of Cl.sub.2:
41.5.
[0059] It is clearly seen from the above table that the addition of
the chloroparaffin-based additives allows the flow threshold of the
control silicone grease to be substantially increased.
* * * * *