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Description  |
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Since their development in the late 1930's, silicones have become widely
known and utilized. Silicones feature valuable properties which make them
useful in some special applications. All of the silicones exhibit the
properties of not being wet by water and of resistance to relatively high
temperatures. The oils also have the unique property of remaining fluid at
low temperatures. These features of silicone oils have made them useful in
a variety of applications including use as dielectrics, solvents,
mechanical working media, dampening agents, lubricant base oils and
processing aids. However, in addition to their favorable features,
silicone oils are marked by some rather serious deficiencies which tend to
restrict their usefulness.
Silicone oils, without supporting additives, are not oxidatively stable at
high temperatures and break down to form gels. Further, they are
characterized by poor steel-on-steel lubricity properties. To compensate
for these deficiencies, various known materials can be employed as
additives. Unfortunately, silicone oils are poor solvents for many of the
commonly used functional fluid additives; and, the silicones demonstrate
poor response to many of the few additives that do dissolve in them.
It has now been discovered, according to the present invention, that novel
compositions comprising silicone oils and silicate cluster compounds
exhibit several significant improvements over conventional silicone oil
fluids. The addition of these silicate cluster compounds to the silicone
oil effects a distinct improvement in steel-on-steel lubricity, and also
lowers the pour point of the resulting fluid. As perhaps the most critical
improvement factor, the presence of the silicate cluster compounds in the
silicone oil composition accomodates the ready solubilizing of various
useful additive materials which otherwise are not sufficiently soluble in
silicone oil for practical utility. The compositions of the present
invention exhibit enhanced response to various additives as well.
The silicone oils which form the base of the present invented composition
can be any such silicone material. Conventional silicone oils include
alkyl silicones, polydimethyl silicones, polyphenylmethyl silicones,
polychlorophenylmethyl silicones, polytrifluoropropyl silicones, and the
like. Such oils are prepared from organo-silicon compounds by methods well
known in the art. Polydimethyl silicones, for example, which are
preferred. commonly are formulated by hydrolysis of dimethyl silicon
dichloride to form a controlled molecular weight water-insoluble oily
polymer.
Silicate cluster compounds form an essential element of the invented
compositions. These compounds include alkoxysilane cluster compounds,
alkoxysilanol cluster compounds, halogenated alkoxysilane cluster
compounds, alkoxysilane multiple cluster compounds, and silicone bridged
alkoxysilane double cluster compounds. Such compounds and their
preparation are more fully described in commonly assigned U.S. Pat. Nos.
3,960,913; 3,965,135; 3,965,136; 3,992,429; 4,058,546; and 4,086,260. The
disclosures of all of these respective patents hereby are incorporated by
reference in their entireties.
The use of alkoxysilane cluster compounds, alkoxysilane multiple cluster
compounds, and silicone bridged alkoxysilane double cluster compounds
(more fully described in U.S. Pat. Nos. 3,965,136, 3,992,429, and
4,058,546 respectively) is preferred. Alkoxysilane cluster compounds are
particularly preferred. These alkoxysilane clusters have the general
formula:
##STR1##
wherein R is hydrogen, alkyl, alkenyl, aryl or aralkyl and each R' is
independently selected from the same group as R with the proviso that at
least a majority of R' radicals on each Si are sterically hindered alkyl
groups having at least 3 carbon atoms.
Desirably, R is hydrogen, an alkyl or alkenyl having about 1 to about 18
carbon atoms or an aryl or aralkyl having about 6 to about 24 carbon
atoms. Preferably, R is hydrogen, an alkyl having about 1 to about 8
carbon atoms or an aryl or aralkyl having about 6 to about 14 carbon
atoms. In Formula (I), each R' is independently selected from the same
group as R, with the proviso that at least a majority of the R' radicals
are sterically hindered alkyl groups having at least 3 carbon atoms. The
desired and preferred groups for R' are the same as for R subject to the
preceding proviso. Desirably, at least a majority of the R' radicals are
sterically hindered alkyl groups having about 3 to about 24 carbon atoms
and preferably are sterically hindred alkyl groups having about 4 to about
12 carbon atoms. By sterically hindered alkyl groups is meant alkyl
radicals which contribute to the hydrolytic stability of the molecule,
i.e., which inhibit the reaction of water with the silicon-oxygen or the
carbon-oxygen bonds in the molecule. Exemplary of sterically hindered
alkyl radicals are non-linear primary alkyl radicals having a beta
position side chain of at least 2 carbon atoms, secondary alkyl radicals
and tertiary alkyl radicals. Particularly useful sterically hindered alkyl
groups include sec. butyl, isobutyl, 2-ethyl butyl, 2-ethyl pentyl,
3-ethyl pentyl, 2-ethyl hexyl, 3-ethyl hexyl, 2,4-dimethyl-3-pentyl, etc.
The alkoxysilane multiple cluster compounds feature the general formulae:
##STR2##
wherein a=2, 3 or 4; M is a substituent branched or straight chain
hydrocarbon radical; R is hydrogen, alkyl, alkenyl, aryl or aralkyl and
each R' is independently selected from the same group as R with the
proviso that at least a majority of R' radicals on each Si are sterically
hindered alkyl groups having at least 3 carbon atoms.
The compounds used in the present invention are those represented by the
above formulas wherein a=2, 3 or 4, as mentioned. Desirably, a=2 or 3 and
preferably a=2. The substituent M is defined as a substituted or
unsubstituted hydrocarbon radical, either branched or straight chained and
branched radicals are preferred. By hydrocarbon radical is meant both
oxylated radicals and radicals which have not been oxylated. Thus, M may
be a straight or branched chain hydrocarbon diradical, triradical or
tetraradical containing carbon and hydrogen atoms, with or without inert
substituents. Alternatively, M may be a straight or branched chain
hydrocarbon diradical, triradical or tetraradical having one or more ether
and/or ester units, with or without inert substituents. The radical M is a
hydrocarbon radical, as defined, having up to about 25 carbon atoms,
desirably having about 2 to about 18 carbon atoms, and preferably having
about 4 to about 12 carbon atoms. The hydrocarbon radical may, as
mentioned, be unsubstituted or it may be substituted and these
substituents include, e.g., hydroxy groups, phenyl groups and any
substituents which do not interfere with the hydrolytic stability of the
molecule to an undesirable degree.
R is defined as hydrogen, an alkyl, alkenyl, or aryl or aralkyl radical.
Desirably, R is hydrogen, an alkyl or alkenyl having about 1 to about 18
carbon atoms or an aryl or aralkyl having about 6 to about 24 carbon
atoms. Preferably, R is hydrogen, an alkyl having about 1 to about 8
carbon atoms or an aryl or aralkyl having about 6 to about 14 carbon
atoms. In the above formulas, each R' is independently selected from the
same group as R, with the proviso that at least a majority of the R'
radicals are sterically hindered alkyl groups having at least 3 carbon
atoms. The desired and preferred groups for R' are the same as for R
subject to the preceding proviso. Desirably, at least a majority of the R'
radicals are sterically hindered alkyl groups having about 3 to about 24
carbon atoms and preferably are sterically hindered alkyl groups having
about 4 to about 12 carbon atoms. By sterically hindered alkyl groups is
meant alkyl radicals which contribute to the hydrolytic stability of the
molecule. Exemplary of sterically hindered alkyl radicals are non-linear
primary alkyl radicals having a beta position side chain of at least 2
carbon atoms, secondary alkyl radicals and tertiary alkyl radicals.
Particularly useful sterically hindered alkyl groups include sec. butyl,
isobutyl, 2-ethyl butyl, 2-ethyl pentyl, 3-ethyl pentyl, 2-ethyl hexyl,
3-ethyl hexyl, and 2,4-dimethyl-3-pentyl, etc.
The silicone-bridged alkoxysilane double cluster compounds have the general
formula:
##STR3##
wherein n is an integer from 0 to 300; R is hydrogen, alkyl, alkenyl,
aryl, aralkyl or --OSi(OR').sub.3 ; each R' is independently selected from
alkyl, alkenyl, aryl or aralkyl with the proviso that at least a majority
of R' radicals are sterically hindered alkyl groups having at least 3
carbon atoms; and R" and R'" are independently selected from hydrogen,
alkyl, alkenyl, aryl, aralkyl, hydroalkyl, and halo or cyano substituted
alkyl, alkenyl, aryl, aralkyl, and hydroalkyl.
As defined above, the group R of the Formula IV reactant is hydrogen,
alkyl, alkenyl, aryl, aralkyl or --OSi(OR').sub.3. Preferably, R is
hydrogen, alkyl or alkenyl having about 1 to about 18 carbon atoms or aryl
or aralkyl having about 6 to about 24 carbon atoms. Most preferably, R is
hydrogen, alkyl or alkenyl having about 1 to about 8 carbon atoms or aryl
or aralkyl having about 6 to about 14 carbon atoms.
Also as defined above, R' groups of Formula IV are independently selected
from alkyl, alkenyl, aryl or aralkyl, with the proviso that at least a
majority of the R' radicals are sterically hindered alkyl groups having at
least 3 carbon atoms. Preferably, at least a majority of the R' radicals
are sterically hindered alkyl groups having about 3 to about 24 carbon
atoms and, most preferably, are all sterically hindered alkyl groups
having about 4 to about 12 carbon atoms. By sterically hindered is meant
alkyl radicals which contribute to the hydrolytic stability of the
molecule, i.e., which inhibit the reaction of water with the
silicon-oxygen or the carbon-oxygen bonds in the molecule. Exemplary of
sterically hindered alkyl radicals are non-linear primary alkyl radicals
having a beta position side chain of at least 2 carbon atoms, secondary
alkyl radicals and tertiary alkyl radicals. Particularly useful sterically
hindered groups include sec. butyl, isobutyl, 2-ethyl butyl, 2-ethyl
pentyl, 3-ethyl pentyl, 2-ethyl hexyl, 3-ethyl hexyl,
2,4-dimethyl-3-pentyl, etc.
The silicate cluster fluids are miscible with silicone oils in all
proportions. Accordingly, in the present composition, any effective
proportion of silicate cluster compounds may be used. As illustrated
below, the addition of silicate cluster compounds results in increased
lubricity properties of silicone oil compositions. Also, because of the
hereinbelow described solubility effect of the silicate cluster,
increasing amounts of these compounds permit accommodation of increasing
amounts of property-enhancing additive ingredients. Generally, the cluster
compounds are added in a proportion ranging from about 5 to about 95
percent by weight. Preferably, however, due to an unexplained inverse
lubricity response found at near 50/50 blend ratios, the silicate cluster
compounds are included in the silicone oil composition in a proportion
ranging from about 20 to about 45 percent by weight, most preferably about
25 to about 40 percent; and in a proportion ranging from about 60 to about
95 percent of the cluster compounds by weight, most preferably about 65 to
about 90 percent.
There are various inhibitors and other additives that are commonly known in
the functional fluid art that can be employed in the presently described
silicone oil composition to control or modify various chemical and
physical properties of the fluids. The general term "inhibitor" is used
for those additives which increase resistance to chemical changes. The
ultimate function of an inhibitor is to maintain both the mechanical parts
of the system and the fluid as close to their original conditions as
possible.
Among the various types of additives which can be added to the silicone
fluids of this invention are included: inhibitors for pH and corrosion
control, anti-oxidants, rust inhibitors, viscosity-index improvers,
pour-point depressants, wear additives, lubricating additives,
anti-foamants, stabilizers, demulsifiers, dyes and odor suppressants.
Generally, the total amount of additives which may be incorporated into
the fluid composition will vary depending on the particular composition
and the desired properties. More particularly, the total amount of
additives will comprise from 0 to 20 percent and preferably from 0.1 to
8.0 percent by weight based on the total weight of the fluid composition.
A wide range of materials have found utility as antioxidants and any of
these can be used in the compositions of the present invention. Generally
the amount of antioxidant used will vary from 0 to 3 percent and
preferably will be from 0.001 to 2.0 percent by weight based on the total
weight of the fluid composition. Typical antioxidants include phenolic
compounds, such as 2,2-di-(4-hydroxyphenyl)-propane, phenothiazine,
phenothiazine-carboxylic acid esters, N-alkyl or N-arylphenothiazines such
as N-ethyl-phenothiazine, N-phenyl-phenothiazine; polymerized
trimethyldihydroquinoline; amines, such as phenyl-alphanaphthylamine,
dioctyl diphenylamine, p-isopropoxy-diphenylamine, N,N-dibutyl-p-phenylene
diamine, diphenyl-p-phenylene-diamine,
N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine,
N,N'-diisopropyl-p-phenylene-diamine, p-hydroxydiphenylamine; hindered
phenols such as dibutyl cresol, 2,6-dimethyl-p-cresol, butylated
2,2-di-(4-hydroxyphenyl)-propane, n-butylated aminophenol, butylated
hydroxyanisoles, such as 2,6-dibutyl-p-hydroxyanisole; anthraquinone,
dihydroxy-anthraquinone, hydroquinone, 2,5-di-tertiary butylhydroquinone,
2-tertiary butylhydroquinone, quinoline, p-hydroxydiphenylamine, phenyl
benzoate, p-hydroxy-anisole, pyrocathechol, styrenated phenol, and
polyalkylpolyphenols. Mixtures of the above-mentioned antioxidants can be
employed, if desired.
Inhibitors for corrosion control can be employed. These inhibitors are
generally added in an amount of from 0.01 to 8.0 percent by weight based
on the total weight of the fluid composition and preferably from 0.2 to
6.0 percent by weight on the same basis. Useful inhibitors include
salicylyl-monoethanolamine, di-.beta.-naphthyl-p-phenylene-diamine,
N,N'-disalicylidene-1,2-propanediamine, N,N'-disalicylyl-ethylene-diamine,
phosphites, such as triphenyl phosphite, tri(tertamylphenyl) phosphite,
diisopropyl phosphite; mercaptobenzotriazole; triazoles including
benzotriazole, 1,2-naphthotriazole, 4-nitrobenzotriazole, tolutriazole,
aminobenzotriazoles such as 5-acylaminobenzotriazole, and alkyl-triazoles
having 1 to 10 carbon atoms in the alkyl group as exemplified by
methyl-triazole, ethyl-triazole, n-propyl-triazole,
tertiary-butyl-triazole, hexyl-triazole, isodecyl-triazole. Other useful
corrosion inhibitors include adenine, 4-methylimidazole,
3,5-dimethyl-pyrazole, 6-nitroimidazole, imidazole, benzimidazole,
indazole, ammonium dinonylnaphthalene-sulfonate, diolyl thiodipropionate,
ethyl benzoate, ethyl p-aminobenzoate,
4,4'-methylene-bis(2,6-di-tert.-butylphenol),
4-hydroxymethyl-2,6-di-tert.-butylphenol,
4,4'-methylene-bis(4-methyl-6-tert.-butylphenol), salicylyl-o-aminophenol,
2,6-di-tert.-butyl-2-dimethylamino-p-cresol,
4,4'-thiobis-(6-tert.-butyl-o-cresol). Mixtures of the above inhibitors
can be employed if desired.
An important class of inhibitors used in functional fluids are rust
inhibitors. Rust preventative additives consist of polar compounds capable
of being absorbed at the metal-fluid interface. These additives generally
include: esters such as sorbitan monooleate, barium petroleum sulfonate,
butyl stearates, butyl naphthenates; nitrogen compounds such as amines and
amides; phosphorus compounds, such as phosphorus acid esters; and metal
soaps, such as aluminum stearate. These rust inhibitors generally are used
in an amount ranging from about 0.01 to about 10 percent; preferably from
about 0.1 to about 2 percent.
Lubricating additives may also be included in the present compositions.
These additives are often classified into three indistinct overlapping
groups-extreme pressure agents, anti-wear agents, and lubricity agents.
Such additives are represented by sulfur-containing compounds, reactive
halogen-containing compounds, and phosphorus-containing compounds. Typical
representatives include zinc dialkylphosphorodithionates, phosphate
esters, phospho-sulfurized fats and hydrocarbons, chlorinated kerosenes
and waxes, xanthates, sulfides and trithiocarbonates. These lubricity
additives generally are employed in an amount ranging from about 0.1 to
about 10 percent; preferably about 0.2 to about 2.0 percent.
The above noted inhibitors and additives are merely exemplary and are not
intended as an exclusive listing of the many well-known materials which
can be added to functional fluid compositions to obtain various desired
properties. Numerous additives useful in hydraulic fluids are disclosed in
Introduction to Hydraulic Fluids by Roger E. Hatton, Reinhold Publishing
Corp., (1962).
The following examples illustrate various embodiments of the present
invention; the examples, however are intended to be illustrative and not
limiting in nature.
EXAMPLES I-IX
In each of the examples, a mixture was prepared consisting of about 32.5
parts by weight of a silicate cluster compound and about 67.5 parts by
weight of a silicone oil. The resulting blends exhibited the viscosity,
pourability, lubricity, and flash point properties reported on Table A,
below. As shown in the Table, the addition of the silicate cluster
compound served to effect a marked improvement in steel-on-steel
lubricity. Comparative Examples 1-6 represent samples of the silicate
cluster compounds and the silicone oils alone; Examples I-IX use blends of
these silicate clusters and silicone oils, as indicated by Comparative
Example numbers (e.g., "Cluster 1/Silicone 4" represents a blend of the
silicate cluster of Comparative Example 1 with the silicone oil of
Comparative Example 4).
TABLE A
__________________________________________________________________________
Lubricities
Viscosities in cst
Pourability @ -110.degree. F.
4- 4-
Example No.
Fluid Composition
100.degree. F.
210.degree. F.
-65.degree. F.
VI.sub.E
1 hr. Ball.sup.7
Falex.sup.8
Ball.sup.9
Falex.sup.9
__________________________________________________________________________
Comp. Ex. 1
Silicate Cluster.sup.1
39.03
10.52
3385 288
Pours .7 0
Comp. Ex. 2
Silicate Cluster.sup.2
39.75
10.98
6016 298
Pours .63
Comp. Ex. 3
Silicate Cluster.sup.3
48.28
13.62
4292 309
Pours .55
Comp. Ex. 4
Silicone Oil.sup.4
40.1
16.31
523 434
Solid 2.4
466
Comp. Ex. 5
Silicone Oil.sup.5
92.43
35.17
2265 408
Pours 2.44
Comp. Ex. 6
Silicone Oil.sup.6
52.71
18.24
1395 377
Pours 1.28
78
Silicate Cluster/
Silicone Oil Mixes
Ex. I Cluster 1/Silicone 4
37.29
14.07
756 409
Pours 1.75
380 1.17
228
Ex. II Cluster 2/Silicone 4
38.93
14.65
937 407
Pours 1.63
Ex. III
Cluster 3/Silicone 4
39.43
14.78
829.8
405
Pours 1.60
Ex. IV Cluster 1/Silicone 5
74.30
25.84
2357 381
Pours 1.64
Ex. V Cluster 2/Silicone 5
74.43
26.11
2748 383
Pours 1.64
Ex. VI Cluster 3/Silicone 5
75.33
26.67
2517 386
Pours 1.66
Ex. VII
Cluster 1/Silicone 6
45.73
15.05
1914 359
Pours 1.19
126
Ex. VIII
Cluster 2/Silicone 6
48.74
16.04
2319 359
Pours 1.39
Ex. IX Cluster 3/Silicone 6
48.88
16.12
2137 360
Pours 1.15
__________________________________________________________________________
.sup.1 tris(trisec-butoxysiloxy)methylsilane available from Olin
Corporation under the trademark "Silicate Cluster 102".
##STR4##
.sup.3 silicone-bridged double cluster
3,7di[tri-sec-butoxysilyloxy]-3,5,5,7-tetramethyl-1,1,1,9,9,9-hexa-sec-bu
oxy pentasiloxane.
.sup.4 dimethyl polysiloxane available from Dow Corning under the
trademark "DC561".
.sup.5 phenylmethyl polysiloxane available from General Electric under th
trademark "SF 1153".
.sup.6 chlorophenyl polysiloxane available from General Electric under th
trademark "Versilube F50".
.sup.7 40 kg, 1200 RPM, 167.degree. F., 1 hr.
.sup.8 100 # gauge load, 15 min.
.sup.9 includes 1% dialkyl diarylamine antioxidant available from
CibaGeigy under the trademark "Irganox LO6", .1% p,p'-dioctyl
diphenylamine antioxidant available from R. T. Vanderbilt under the
trademark "Van Lube 81", and 2% P,S,Zn wear additive available from
Lubrizol under the trademark "Lubrizol 1395".
EXAMPLES X-XVIII
To demonstrate the ability of the silicate cluster compounds to enhance the
additive solubility of silicone oil fluids, 50/50 blends were prepared of
selected cluster compounds and silicone to which were added various common
fluid additives. The solubility of these additives in the respective
blends is reported in Table B, below. Comparative Examples 7-9 illustrate
the solubility of the additives in silicone oil alone.
TABLE B
__________________________________________________________________________
Solubilization of Additives in Silicones and Silicone/Silicate Cluster
Blends
__________________________________________________________________________
Ex. X Ex. XI Ex. XII
Comp. Ex. 7
Silicone.sup.1 /
Silicone.sup.1 /
Silicone.sup.1 /
Additive @1%
Fluid Composition
Silicone Oil.sup.1
Cluster.sup.4
Cluster.sup.5
Cluster.sup.6
__________________________________________________________________________
Antioxidant.sup.7
RT/-40.degree.
soluble/insoluble
soluble/insoluble
soluble/soluble
soluble/soluble
Wear Additive.sup.8 soluble/insoluble
soluble/soluble
soluble/soluble
--/--
Lubricity Promoter.sup.9
insoluble/insoluble
soluble/soluble
soluble/soluble
soluble/soluble
Corrosion Inhibitor.sup.10
insoluble/insoluble
soluble/soluble
soluble/insoluble
--/--
Rust Inhibitor.sup.11 insoluble/insoluble
soluble/soluble
soluble/insoluble
soluble/slightly
soluble
__________________________________________________________________________
Ex. XIII Ex. XIV Ex. XV
Comp. Ex. 8
Silicone.sup.2 /
Silicone.sup.2 /
Silicone.sup.2 /
Fluid Composition
Silicone Oil.sup.2
Cluster.sup.4
Cluster.sup.5
Cluster.sup.6
__________________________________________________________________________
Antioxidant.sup.7
RT/-40.degree.
soluble/soluble
--/-- --/-- soluble/soluble
Lubricity Promoter.sup.9
insoluble/insoluble
soluble/soluble
soluble/soluble
soluble/soluble
Rust Inhibitor.sup.11 insoluble/insoluble
soluble/soluble
soluble/soluble
soluble/soluble
__________________________________________________________________________
Ex. XVI Ex. XVII Ex. XVIII
Comp. Ex. 9
Silicone.sup.3 /
Silicone.sup.3 /
Silicone.sup.3 /
Fluid Composition
Silicone Oil.sup.3
Cluster.sup.4
Cluster.sup.5
Cluster.sup.6
__________________________________________________________________________
RT/-40.degree.
slightly
Antioxidant.sup.7 soluble/insoluble
soluble/soluble
soluble/soluble
soluble/soluble
Lubricity Promoter.sup.9
insoluble/insoluble
soluble/soluble
soluble/soluble
soluble/soluble
Rust Inhibitor.sup.11 insoluble/insoluble
soluble/soluble
soluble/soluble
soluble/soluble
__________________________________________________________________________
.sup.1 dimethyl polysiloxane available from Dow Corning under the
trademark "DC 561".
.sup.2 phenylmethyl polysiloxane available from General Electric under th
trademark "SF 1153".
.sup.3 chlorophenyl polysiloxane available from General Electric under th
trademark "Versilube F50".
.sup.4 tris(tri-sec-butoxysiloxy)methylsilane available from Olin
Corporation under the trademark "Silicate Cluster 102".
##STR5##
.sup.6 silicone bridged double cluster
3,7di[tri-sec-butoxysilyloxy]-3,5,5,7-tetramethyl-1,1,1,9,9,9-hexa-sec-bu
oxy pentasiloxane.
.sup.7 phenyl .alpha.-naphthylamine available from Union Carbide under th
name "PANA".
.sup.8 P,S,Zn wear additive available from Lubrizol under the trademark
"Lubrizol 1395".
.sup.9 ashless P,S wear additive available from R. T. Vanderbilt under th
trademark "Van Lube 719".
.sup.10 rust inhibitor available from Lubrizol under the trademark
"Lubrizol 850".
.sup.11 barium sulfonate rust inhibitor available from R. T. Vanderbilt
under the trademark "Nasul BSN".
EXAMPLES XIX-XXX
To illustrate the effect of varying the proportions of silicate cluster
compounds with silicone oil compositions, a series of blends was prepared.
Table C, below, shows the pourability, viscosity, flash point and
lubricity properties accomplished with blends of
tris(tri-sec-butoxysiloxy)methylsilane (available from Olin Corporation
under the trademark "Silicate Cluster 102") and dimethyl polysiloxane
(available from Dow Corning under the trademark "DC 561"). For unexplained
reasons, an inverse lubricity effect was noted with blends approaching
50/50. The table indicates the enhanced lubricity and pour point results
achieved with the addition of the silicate cluster compound to the
silicone oil.
TABLE C
__________________________________________________________________________
Blends of tris(tri-sec-butoxysiloxy)methylsilane and Dimethyl
Polysiloxane
Examples XIX XX XXI XXII
XXIII
XXIV
XXV XXVI
XXVII
XXVIII
XXIX
XXX
% Silicone 0 10 25 37.5
50 56.25
60 62.5
65 75 90 100
__________________________________________________________________________
Pour Point
1 hr., -110 to 120.degree. F.
Pours
Pours
Pours
Pours
Pours
Pours
Pours
Pours
Pours
Pours
Pours
Solid
Viscosity, 100.degree. F.
38.2
36.11
36.0 36.14 39.0 40.4
40.1
210.degree. F.
10.2
10.53
11.43 12.80 14.94
16.22
16.31
VI.sub.E 285 315 346 386 413 429 434
Seta Flash Point .degree.F.
397 397 402 412 450 485 520
4-Ball Wear.sup.1
0.63
0.69
1.71
1.94
2.43
1.65
1.76
1.63
1.68
1.78 2.13
2.39
0.61
0.66
1.64
1.92
2.43
1.77
1.79
1.71
1.68
1.81 2.05
2.42
0.63
0.60
1.32 2.20
1.72
1.79
1.74
1.73
1.80 2.07
0.66
0.60
1.74 2.35 1.74 2.10
0.58 1.70 2.31 1.57
0.57
__________________________________________________________________________
.sup.1 40 kg, 1200 RPM, 167.degree. F., 1 hr.
* * * * *
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