Note: Descriptions are shown in the official language in which they were submitted.
1~ 45~9 8SI-1594
This invention relates to organopolysiloxane polymers
and more particularly to phenyl-contaïning organopolysiloxane
fluid polymers.
In the past, the:re were three major types of silicone
polymers which comprise nearly all of the phenyl-containing
organopolysiloxanes. These included ~1) those siloxanes with
phenyl and methyl groups on the same si.licon atom, (:2) those
: siloxanes with two phenyls on one silicon and two methyls on the
next or subsequent silicon atom, and (3~ those. siloxanes
containing phenyl trimethylsilyl units stopped with trimethylsilyl
units.
An example of the first type includes polymers of
the structure
. CH3 ~ CH3 ~ ~ CH3 ~ C,H3
CH3 - Si - t si a ) -t si o ~ si CH
CH3 ~ Ph / ~CH3 J CH3 .
X Y
wherein Ph is phenyl and wherein, in general, x = 0.05 y to
y= O.
The second major type includes those polymers having
the structure,
CIH3 /'C,H3 ~ ~ Ph ~ ,CH3
CH3 - Si _ o ~ Si - O - ~ Si- O ~- - Si - CH3
CH3 ~CH3 ~ ~ Ph J CH3 ;~
where Ph is phenyl and wherein, in general, x = 0.05 y to x = y. :
The third group of polymers has the structure -
,CH3 , 3
,CH3 3, 3 CH3Si CH3 CH -
CH3 - Si _ o Si - O Si - O --- Si - CH
CH3 Ph Ph CH3
wherein the polymer length varies up to about 25 phenyl
containing units.
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For varicus reasons, these prior art silicone fluids
are characterized with both technical and commercial problems.
For example, the first of the above-identified silicone fluidæ
are necessarily made from a ~tarting material, i.e., methyl-
phenyldichlorosilane, which comes from an expen~ive Grignard
process while the polymers associated with the other above-
identified classic structure6 are characterized with processing
problems. For example, those polymers containing both diphenyl
and dimethyl units have been found to be excessively volatile
and moreover are difficult to manufacture in low vooai~ form
which i8 oftentimes desirable.
The uses for these hereinabove described silicone
polymers are of course widespread, depending upon molecular
weisht and structure, and are well known. Included among these
uses are, for example, lubricity additives for plastics, high
temperature grease components and general mechanical fluids.
; More specifically, one recently significant use of
phenyl-containing organopolysiloxane fluids ha~ been a~ internal
mold release agents in polycarbonates. See, for example, U.S.
Patent No. 3,751,519 isffued August 7, 1973. However, prior art
phenyl organopolysiloxane fluids have not been totally ~ati~-
factory for polycarbonates as a result of their low solubility
in the polycarbonate. Moreover, transparency ueually desired in
polycarbonate products is usually lost when these prior art
phenyl-containing organopoly~iloxane fluids are added thereto.
Accordingly, it i~ one object of this invention to
provide a novel class of phenyl-containing organopolysiloxane
fluids.
Another object of this invention is to provide novel
phenyl-containing organopolysiloxanes which are easily prepared
in an economic manner.
8SI-1594
10~34519
Still another object of this invantion i~ to provide
novel phenyl-containing organopolysiloxane fluids having a
high phenyl content, whicht if desired, may be prepared in low
viscosity form and which are charac~erized witn low volatility.
Still another object of this invention i8 to provide
phenyl-containing organopolysiloxane fluids, u~eful as internal
mold release additives and having high solubility in
polycarbonates.
A still further object of this invention is to provide
novel phenyl-containing fluids of varied utilities, including
additives for plastics, high temperature grease components,
mechanical fluids and the like.
A still further object of this invention is to provide
polycarbonate co~positions comprising the novel phenyl organo-
polysiloxane fluid~ of this invention, said polycarbonate
compositions being characterized with transparency and internal
mold release properties.
These zlnd other ob~ects are accomplished herein by
providing phenyl--containing organopolysiloxane fluids char-
acterized by the following basic structure,
CH3 ,Ph ~ CH3 ~ ~ ,Ph
(I) CH3 - Si - OSi _ o ~ Si - 0 ~ Si - 0 ~ R
J y\~ ~ :
wherein x and y are values ~ufficient to provide a phenyl
content of from about 7 weight percnnt to about 80 weight per-
cent, and where Ph is phenyl, and wherein R is selected from the
group consisting of hydrogen and trimethylsilyl, i.e.,
,H3
Bi - CH3 and mixtures thereof.
CH3
The novel phenyl-containing organopolysiloxane fluids
characterized by Formula I hereinabove are made by the solvent
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hydroly~is of diphenyldichlorosilane and dimethyldichlorosilane.
In general, this solvent hydrolysis process involves preparing
a blend of diphenyldichlorosilane, dimethyldichlorosilane, and
a water-immiscible organic solvent.
` Suitable organic solvent~ are, for example, any water-
immiscible organic solvent which i~ inert to the hydrolysis
reactants during hydrolysis, and in which the hydrolyzate i~
soluble 80 as to provide for its separation. More specifically,
suitable organic solvents include benzene, toluene, xylene, and
the li~e; esters such as butyl acetate, ethyl acetate and the
like; and ethers such as diethyl ether, dioxane and the like.
A preferred organic ~olvent i8 toluene. The amount of or~anic
solvent employed may vary within a wide range and is generally
within the range of ~rom about 10~ to about 50h by weight of the
total weight of the blend of organohalo~ilanes, preferably about
25% by weight. - -~
For purpoces of this invention, the ratio of diphenyl-
~hlorosilane to dimethylchlorosilane in the organohalosilane
blend which is subjected to hydrolysis i~ from about 1.5 to 1
to about 4 to 1 by weight, re~pectively. Preerably, the ratio
of diphenylchlorosilane to dimethylchlorosilane i8 about 3 to 1.
The afore-described mixture of organohalosilanes in
organic solvent is admixed with and agitated in water which ha~
been preheated to from about 20 to about 85 C, preferably from
about 60 to about 65 , the addition being carried out slowly
over a period of, for example, from about 1 to about 2 hours,
while maintaining a temperature of from about 60C to about
85C, preferably from about 75C to about 85 C. The resultant
hydrolysis mixture i8 allowed to ~ettle and the ~ aqueous acid
layer (bottom) is separated and discardea. The remaining organic
layer is generally washed several times with, for example, 15%
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i~845~9 8SI-1594
sodium sulfate sOlution, until the HCl content is below about
10 parts per million. At this point, the water i9 azeotropically
removed from the hydrolysis mixture at a temperature which should
not exceed about 115 C~ The material remaining, hereinafter
referred to as the hydrolyzate, i8 a mixture o linear siloxanes
(chainstopped with diphenyl silanol unit~), cyclic polymers,
and organic solvent.
The hydrolyzats is then saturated with anhydrous
ammonia and trimethylchlorosilane is slowly added thereto. The
trimethylchlorosilane act~ as a chain~topping agent and replaces
the silanol groups with trimethylsiloxy chain-stopping units.
The amount of trimethylchlorosilane which is employed varies
with the amount of hydroxyl group replacement desired. For
purposes of tnis invention, the trimethylchlorosilane is
employed in amounts from about 9.5 to 25.5 weight percsnt of the
weight of the hydrolyzate. More specifically, for polycarbonate
additive purposes, the amount of trimethylchlorsilane chain-
stopping agent w ed ranges from about 11.4% to 19% by woight
of the total weight of the hydrolyzate, providing a trimethyl-
siloxy unit content for the fluid of from about 12 to about 21percent by weight. ~ fter agitating the mixture for about one hour, the
mixture is washed with, for example, 15% sodium sulfate until
essentially neutral and the aqueous bo~Dm layer is ~eparated and
di~carded. The remaining organic layer i8 wa~hed with, for
example, sodium sulfate, and the organic ~olvent and residual
water is stripped under vacuum, e.g., 25 to 30 mm Hg. at about
150 C. The remaining phenyl-containing organopolysiloxane fluid
is characterized by Formula I hereinabove, wherein x and y are
3~ values sufficient to provide a phenyl content of from about 40
to 80 weight percent and i8 especially well suited a~ an internal
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11)845~9 8SI--1594
mold release additive for polycarbonates since the fluid is
highly soluble in polycarbonates and moreover retains the
desired transparency of the polycarbonates. In general, x and
y have a value of from about 3 to 10 for this purpose.
To obtain particularly high phenyl content, low
volatile organopolysiloxane fluids within ths scope of the
present invention, and which are particularly well suited as
a base stock for all mechanical or hydraulic phenyl silicone
fluids, the afore-described phenyl-containing organopoly-
~iloxane fluid is totally chain~toppsd by employing a sufficient
amount of trimethylchlorosilane to do the same. The substantially
all trimethylsiloxy chainstopped fluid is then subjected to an
equilibration process involving admixing the same with potassium
hydroxide and heating toabout 180 C for about 1 to 2 hours.
If desired, additional trimethylsiloxy chainstopping units may
be added during eguilibration. Strippi~g the mixture at about
250-300C under high vacuum (3-5 mm ~g.) results in a high
phenol content, low volatile, organopolysiloxane fluid
characterized by Formula I above wherein x is about 3 to 10 and
y i8 about 3 to 10 and the phenyl content iB from about 40 to 80
weight percent.
To obtain phenyl-containing organopolysiloxane fluids
within the scope of this invention and which are especially
suitable a~ mechanical fluids and high temperature grease
components the afore-described hydrolysis process for preparing
the polycarbonate additive i~ continued by completely chain-
stopping the fluid by the addition of a sufficient ~uantity
of trimethylchlorosilane. The resultant mixture is equilibrated
with potassium hydroxide at a temperature in the range of from
about 180 C to 200C for about one hour. During equilibration
octamethylcyclotetra~iloxane and trimethylsiloxy containing
units provided, for example, by linear decamethyltetrasiloxane,
8SI-1594
1~45~L9
are added in sufficient quantity to reduce the phenyl content
to a desired amount, generally in the range of from about 38
to 48 weight percent, and to a desired viscosity, generally
100 to 200 centistokes at 25C. In the preferred method of
equilibration, the octamethyltetracyclosiloxane and trimethyl-
siloxy unit material are equilibrated first, then the phenyl-
containing stock i~ added and the equilibration co~tinued for
like about 3 hours.
The resultant equilibrate is ~tripped to about 280C
under very high vacuum, e.g., 3-5 mm ~g.
To obtain a fluid especially useful for transparent
greases and controlled den3ity greases, the fluid identified
hereinabove, as being particularly useful às an internal mold
release agent for polycarbonate~, is further modified by the
addition thereto of octamethylcyclotetrasiloxane (sufficient
to lower the phenyl content to about 30 weight percent) and
equilibrating and stripping the resultant mixture as de~cribed
hereinabove.
It is clear to those skilled in the art that the
phenyl-containing organopolysiloxanes of this invention as
particularly characterized by Formula I hereinabove are
particularly di~tinguished over the prior art phenyl-containing
silicone fluids in that the present fluids comprise trimethylsikxy
chainstopping units which are directly attached primarily to
diphenylsilo~y units. This accounts for the advantageous
solubility properties of the present fluids in polycarbonates,
in addition to accounting for the other advantageous properties ~-
herebefore described.
The polycarbonates which are contemplated herein in
admixture with the above-identified internal mold relea~e
phenyl-containing organopolysiloxane additives of this invention
include those aromatic polycarbonates prepared by reacting a
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8SI-1594
845:~L9
dihydric phenol and a carbonate precur~or. The reaction mixture
can also include minor amounts of other additives or other
amounts of other reactive monomeric constituents. It can
also include copolymers of two or more different dihydric
phenols.
Specifically, examples of dihydric phenols that can
be empl~yed to prepare the polycarbonates eontemplated herein
are bis(4-hydroxyphenyl)-methane, 2,2-bis(4-hydroxyphenyl-
propane, 2,2-bis(4-hydroxy-3-methylphenyl)-propane, 4,4-bis-
(4-hydroxyphenyl)-heptane, 2,2-bis(4-hydroxy, 3,5-dichloro-
phenyl)-propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)-propane,
ete.; dihydrie phenol ethers sueh as bis(4-hydroxyphenyl)-ether,
bis(3,5-dichloro-4-hydroxyphenyl)-ether, etc.; dihydroxydiphenyls
such as p,p'-dihydroxy-diphenyl, 3,3'-dichloro-4,4'-dihydroxy-
diphenyl, etc.; dihydroxyaryl sulfones ~uch as bis(4-hydroxy-
phenyl)-sulfone, bis(3,5-dimethyl-4-hydroxyphenyl)-sulfone, etc.;
dihydroxy benzenes, resorcinol, hydroquinones, halo and alkyl-
substituted dihydroxy benzenes ~uch as 1,4-dihydroxy-2-ehloro-
benzene, 1,4-dihydroxy-2,5-diehlorobenzene, 1,4-dihydroxy-3-
methylbenzene, etc.; and dihydroxy diphenyl qulfoxides such as
bis(4-hydroxyphenyl)-sulfoxide, bis(3,5-dibromo-4-hydroxyphenyl)-
sulfoxide, ete. A variety of additional dihydric phenols are
also available to provide earbonate polymers and are disclosed
in U.S. Patents 2,999,835 issued September 12, 1961; 3,028,365
issued April 3, 1962 and 3,153,008 issued October 13, 1964. It
i8, of course, possible to employ two or more different dihydric
phenols or a copolymer of a dihydric phenol with glycol or with
hydroxy or aeid terminated polyester, or with a diboric acid in
the event a carbonate copolymer or interpolymer rather than a
homopolymer is desired for use in the preparation of the aromatic
earbonate polymers of this invention.
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1~845~9
Among the carbonate precursors employed in the afore-
described polycarbonate preparation are included phosgene,
dibromo and diiodocarbonyls as well as the bishaloformates of
dihydric phenols (e.g. bischloroformates of hydroquinone,
bisphenol-A, etc.) or glycols (e.g., bischloroformates of
ethylene glycol, neopentyl glycol, polyethylene glycol, etc.)
A preferred aromatic polycarbonate within the scope
of this invention is prepared from the reaction of phosgene and
2,2,bis(4-hydroxyphenyl)propane), commonly referred to as
bisphenol A.
The preparation of the polycarbonate is generally
carried out in the presence of an acid ac¢eptor which may be
either an organic or an inorganic compound. A suitable organic
acid acceptor is a tertiary amine and includes materials such as
pyridine, triethylamine, dimethylaniline, tributylamine, etc.
The inorganic acid acceptor may be one which can ~ither be a
hydroxide, a carbonate, a dicarbonate ox a phosphate of an alkali
or alkaline earth metal.
Molecul,~r weight regulations may ~180 be smployed in
the preparation of the polycarbonate, such as phenol, cyclohexanol,
methanol, para-tertiary-butylphenol, parabromophenol. Para-
tertiary-butylphenol is preferred.
The phenyl-containing organopolysiloxane fluids of this
invention, as identified by Formula I hereinabove, can be readily
mixed in any convenient manner with the aromatic polycarbonate.
Becau~e the phenyl-containing organopolysiloxane fluids of this
invention are compatible with and highly soluble in the poly-
carbonate material, thorough mixing is easily accomplished with
no difficulty of separation. Thus, when preparing injection
molded pellets, the polycarbonate and the siloxane can be either
premixed or fed independently to the feed hopper of an extruder.
.
,: iQ84519 8SI-1594
Small amounts of the present phenyl-containing
organopolysiloxanes achieve excellent results of mold release
during the molding of the composition. The amount of siloxane
U8ed i8 generally from about 0.01 to about 2.0 weight percent
based on the weight of the polycarbonate, and preferably from
about 0.1 to about 1.0 weight percent thereof. The desired
polycarbonate transparency is not lost by the presence of the
present phenyl-containing organopolysiloxane.
In order that those skilled in the art may better
understand how to practice the present invention, the following
examples are given by way of illustration and not by way of
limitation.
_ ~J EXamDle 1 ~
This example illustrates the preparation of a phenyl-
containing organopolysiloxane fluid within the scope of Formula
I of this invention e~pecially well suited as an internal mold
release agent for aromatic polycarbonates.
There are blended in a vessel 57~7 parts by weight
diphenyldichloro~Llane, 19.2 parts by weight di~ethyldichloro-
silane and 23.1 parts by weight toluene. Water in an amountwhich i8 about 1-1/2 timos the total weight of the organo-
halosilane weight is heated to about 60 C to 61 C in a separate
ve~el. The blend of organohalosilane~ and toluene is slowly
added to the water over a period of about 1-1/2 hours with
agitation and maintaining the temperature at about 75-85 C.
The hydrolysis mixture is stirred for an additional 1/2 hour after
the addition is complete. The bottom aqueous acid laysr is
separated and discarded. The organic layer i8 washed two times
with 15% sodium sulfate and checked for HCl acid content which
sho~d be belo~ 10 parts per million water. The water i8
azeotropically removed at a temperature which does not exceed
115C. To the remaining hydrolyzate is added sufficient anhydrous
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1084519 8SI-1594
ammonia to saturate the hydrolyzate and 12.7 partæ by weight
trimethylchlorosilane, in that order. Care is taken not to
lose any ammonia. The mixture i~ stirred for about one hour
at 55 C and then washed with water to remove ammonium chloride.
The aqueous acid bottom layer is separated and discarded. The
organic layer i~ washed with 15% sodium sulfate, until
e~sentially neutral and the re~idual water and toluene is stripped
at about 150 C under a vacuum of about 25-30 mm Hg. The remain-
ing phenyl-containing organopolysiloxane is characterized by
the structure of Formula I hereinabove and has a phenyl content
of 68.85% by weight and the trimethylsiloxy content is 16% by
weight. This material i8 extremely well suited as a poly-
carbonate internal mold release agent.
Example 2
Thi~ example illustrates the preparation of a phenyl-
containing organopolysiloxane fluid within the scope of Formula
j I hereinabove which i~ particularly well suited as a component
for high temperature and as a mechanical fluid.
To 56.65 parts by weight of the phenyl-containing
organopoly~iloxane fluid prepared in Example 1 i~ added about
1.6 parts by weight of decamethyltrisiloxane chainstopper and
41.8 parts by weight octatetramethylcyclosiloxane. 600 parts
per million of potassium hydroxide pellets are added to the
reaction vessel and the resultant admixture i8 equilibrated
at 180 C for about three hours. The reaction mixture is
stripped up to about 280 at high vacuum, e.g., 3 to 5 mm ~g.
The remaining phenyl-containing organopolysiloxane fluid is
characterized by Formula I hereinabove and has a phenyl content
of 39 percent by weight and a trimethylsiloxy content of 18
percent by weight.
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8SI-1594
4519
Example 3
This example illustrates the preparation of a phenyl-
containing organopolysiloxane flui~ within the scope of Formula
I hereinabove which is particularly well suited as a transparent
grease component.
To 42.4 parts of the phenyl-containing fluid prepared
in Example 1 i8 added 57.6 parts of octamethylcyclotetra- -
siloxane and 600 parts per million of potassium hydroxide
; pellets. The mixture is eguilibrated by heating to 180C for
two hours and the refractive index is adjusted by increasing
or decreasing the amount of phenyl content by adding octamethyl-
l cyclotetrasiloxane or the phenyl containing fluid. When the
.1 desired refracti,ve index is achieved, the mixture is cooled to
40C, Fuller's earth is added and the resultant mixture is
filtered through Celite~545 (diatomaceous earth sold by Johns-
1 Manville). The mixture is stripped of~ at a temperature of
i~! about 250 C under high vacuum conditions, e.g., 3 mm Hg.,
leaving the desired transparent grease component which is
characterized by Formula I h~reinabove and has a 30 weight per-
cent content.
This example illustrates the preparation of a phenyl-
containing organopolysiloxane within the scope of Formula I
hereinabove which is characterized with low volatility and high
phenyl content.
The same procedure as in Example 1 is followed except
that 9 parts by weight of trimethylchlorsilane is added to the
hydrolyzate in order to completely chain4top and replace
substantlally all the silanol units with trimethylsiloxy units.
The totally chainstopped material i8 then equilibrated with
potassium hydroxide and stripped such as is done in Example 1.
The resultant material has a phenyl content of-65 weight percent
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8SI-1594
11~845~L~
and demonstrates only an 8% weight loss after being heated at
250 for 24 hours.
Example 5
This example illustrates the preparation of a poly-
carbonate composition within the scope of this invention.
To 99 part~ by weight of a polycarbonate prepared
by reacting essentially equimoles of bisphenol A, i.e., (2,2-bis-
(4-hydroxyphenyl)propane) and phosgene in the presence of an
acid acceptor and a cat~lyst, which polycarbonate has an
intrinsic viscosity of about 0.50, iB added 1 part by weight of
the phenyl-containing organopolysiloxane of Example 1. The
mixture is fed to an extruder and pelletized. The pellets are
thon injection molded into discs of about 3 inches in diameter
and about 1/8 inch thick. The molded disc is easily released
from the mold without sticking and the molded piece is
transparent.
Obviously, other modifications and variations of the
present invention are possible in light of the above teachings.
It i8 therefore t~D be understood that changes may be made in the
particular embodiments of this invention which are within the
full intended scope of the invention as defined by the appended
claim~.
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