Note: Descriptions are shown in the official language in which they were submitted.
132280~
~ -17,873
BLENDS OF SILICONE COPOLYMER AND POLYETHERIMIDE
.
BACKGROUND OF T~E I~E~l'ION
-
The present inven~ion relates to injection
moldable blends of ~ilicone copolymer and polyetherimide.
The silicone copolymer has been found to enhance the
properties of the polyetherimide in the resulting blend
without significantly reducing ~he upper-use temperature of
the polyetherimide.
Prior to the present invention, polyetherimide,
such as shown by Heath et al., United States Patent No.
10 3,847,867, assigned to the same assignee as the presant - -
invention and issued November 12, 1974, have been
used in a variety of applications reguiring a high
performance injection moldable material and a Tg of at least
200DC. Although polyetherimides have exhibited superior
solvent resistance, strength, and flame resista~ce, methods
; for improving such properties as greater oxygen plasma, and
a~omic oxygen resistance, lower dielec~ric constant, lower
: moisture absorption and improved a~hesion are constantly
being ~ought.
On~ method of lowering ~he moi~ure absorption
characteristics of polyetherimide requir~d n c rcui~ board
applications, is by inco~pora~ing silicoQe~, pr ferably in
the form of a silico~e copolymer. It has been ~ound,
however, that althouqh the re~ulting blend often has
superior moisture absorption resistance, a signi~icant
decrease in heat distortion ~empera~ure (~DT) of the
polyetherimide can be experienced, compared to th~ HDT of
the polyetherimide free of silicone copolymer. In additionr
.. ..
,
,
~ 3228~
RD-17,873
if the silicone copolymer is not compatible or miscible with
the polyetherimide, it will be hazy instead of clear, the
blend alao can show a low Tg for the silicone copolymer and
higher Tg for the polyetherimide. It would be desirable,
the~efore, to be able to incorpora~e silicone copolymers
into polyetherimide without ~xperiencin~ a substantial
reduction in the Tg of the r~sulting blend compared to the
initial polyetherimide T~ .
The present invention is based on our discovery
that certain silicone copolymers resulting from the
intercondensation of aromatic bis(etheranhydride), phthalic
a~hydride termina~ed polydiorganosiloxane and aryldiamine,
as defined hereinafker, can be blended wi~h polyetherimides,
as defined hereinafter, to produce a blend of silicone
copolymer and polyetherimide having a Tg of at least 190C.
STATEMENT 0~ THE INVENTION
There is provided by the present invention
silicone copolymer-polyetherimide bl~nds having a Tg of at
least 190C comprising by weight,
(A) about 1-99% of polyetherimide, and
(B) about 99%-1% of silicone copolymer comprising from
about lO to 70 mole percent, and preferably from 2S to
50 mole p~rcent of disilox~ne units of ~he formula,
O o
.. n "
O O
,
:
,
~ 3~2832 RD-17,873
interconden~ed with from about 90 to 30 moLe % and
preferably from 75 to S0 mole percent of etherimide
unlts of the formula,
O O
\C ~ R2 ~ C\ (2)
ll ll
O O
where R i~ a member selected from the class consisting of
the same or different C(l 14) monovalent hydrocarbon
radiçals and C(1_14) monovalent hydrocarbon radicals
substituted with radicals inert during intercondensation,
is a member selected from the class consisting of divale~t
C~2 20) or~anic radical~ and halogenated derivatives
thereof, R2 is a divalent C(6 30) aromatic organic radical,
and n is an integer having a value of 1 to 5 inclusive.
Radicals which are included within R of formula
(1) are, for example, C(l ~) alkyl radicals, such as methyl,
ethyl, propyl, butyl, pentyl; alkaryl radicals such as
d~methylenephenyl, trime~hylen~phenyl; C(6_14) aryl radicals
su~h as phenyl, tolyl, xylyl, naphthyl, anthryl; and
haloge~ated derivatives thereo, such a~ tri~luoropropyl,
chlorophenyl, chloro~aphthyl; cyanoethyl, phthalimido.
Radicals which are includ~d within Rl are, for
example, C(6 2~) aromatic hydrocarbon radical , halogenated
derivative~ of ~uch C(~ 20) hydrocarbon radicals, C(2 ~)
alkylene radicals, and divalent radical~ included within the
formula,
(Q)m
-3-
'
~ 3 2 2 ~ 73
where Q is a member selected from the class consisting of
~ O
-O-, - ~-J ~ -S-, -Cxd2x,
x is a whole number equal to 1 to 5 inclusive, and m is O or
1.
R~dicals included within R2 are, more
particularly,
CH3 CH3 ~I3 ~H~ CH3
~,~, ~ ,~rr~ ~
3 3
CH3 Br Br CH Br Br
and ~ (~33)2
CH3 Br Br 3 Br Br
and divalent organic`radicals included within the formula,
~ (X)m~
where X iæ a member sel2cted from the clas~ consisting of
divalent radicals of the formula~,
~Cy~2y~ R -- ~ S- ::
~32~,8~2 RD-17,873
;
and -S-, where m is O or 1, y is a whole number from 1 to 5.
The preferred polyetherimides which are blended
with the silicone copolymer in the practice of the present
invention can be made by intercondensing aromatic
S bisetheranhydride of the formula,
O o
.. ..
0/ ~ \0 , (3)
.. ..
O O
with aryldiamine of the formula,
NH2RlNH2 , (4)
either under melt conditions or in the presenee of an
organic solvent, where R1 and R2 are as previously defined.
Silicone copolymer used in the praçtice of the
prescnt invention can be made by intercondensing aryldiamine
of formula (4) with a mixture of the aromatic
bis(etheranhydride) of formula ~3) and a bisphthalic
. 15 anhydride polysiloxane, or "PADS", of the formula,
O O
~ r ~ ~
O\ ~ ~ ~i ~ /0 , (5)
.. n ..
O O
where R and n are as previously defined to provide
substantially equal molar amounts of anhydride unctional
~roups and amine functional ~roups of the aryldiamine of
-5~
. ~322~
formula (4). A method for making bisphthalicanhydride
disiloxane within formula (5) is ~hown by J.R. Pratt et al.,
Journal of Organic Chemistry, Vol.38, No.25, (1973) pp.
4272-75.
S Some of the aryldiamines included within formula
(4) which can be used in the practice of the present
invention to make the polyetherimide and the silicone
copolymer are, for example,
m-phenylenediamine,
p-phenylenediamine,
4,4'-diaminodiphenylpropane,
4,4'-diaminodiphenylmethane,
benzidine,
4,4'-diaminodiphenyl ulfide,
4,4'-diaminodiphenyl sulfone,
4,4'-diaminodiphenyl ether;
1,5-diaminonaphthalene,
3,3'-dimethylbenzidine,
3,3'-dimethoxybenzidine,
2,4-diaminotoluene,
2,6-diaminotoluene,
2,4-bis(~-amino-t~butyl)toluene,
bis(p-~-methyl-o-aminopentyl)benzene, and
1,3-diamino~4-isopropylbenzene.
The polyetherimide-silicone copolymer blend can be
made by dissolving the polystheri~ide and ~ilicone copolymer
in an appropriate i~ert organic ~olvent such as chloroform
tD produce a solution havinq about 10 to 40% by weight
solids. The solution blend then can be cast onto
appropriate substrate, ~uch as a glass plate, to a desired
thickness and allow~d to sta~d overnight. The cast film
will be either tran~parent or hazy ~epending upon the
~6-
R~-l 7, ~?3
~22~2
proportions of chemically combined etherimide units and
disiloxane units in the silicone copol~mer. Blends also can
be obtained by combining materials in the melt, with
a~itation, for example in an extruder reactor or heated
mixing bowl.
Blends of silicone copolymer and polyetherimide
can be used in a variety of application~, ~uch as coatings,
adhesives, composite material~, and molding compounds.
The blends have added benefits over
polyetherimides, ~uoh as improve~ oxygen plasma, atomi~
oxygen re~istance, lower dielectric constant, lower moisture
absorption, and improved adhesion. Fillers such as glas~
fiber, carbon fiber, can be incorporated into the blends in
proportions of from 5 to 100 parts by weight of filler, per
hundred parts of blend.
The following example is given by way of
illustration and not by way of limitation. All parts are by
weight.
EXAMPLE
A eries of ~ilicone copolymers were prepared by
effecting reaction between 1,3 bis~4'-phthalic anhydride)-
tetramethyl~isiloxane (PADS), 2,2-bis[4 (3,4-dicarboxy-
phenoxy)phenyl~propane dianhydride (BP~DA), and meta-
phenylenediamine (MPD). In ~ome i~stances para-
phenylenediamine (PPD) was used in combination with MPD.
Reaction of ~he aforementioned reactant~ was conducted in
ortho-dichlorobenzene in the pre~ence of 0.5 weight % N,N-
dimethylaminopyridine (DM~P) to provide a 30 weight % solids
in the reaction mixture. Water of imidization was removed
by azeotropic distillation of ~he reaotion mixture at
temperature~ in the range of about 170~C. After removal of
-7~
RD-11,873
~322~02
water, the reaction mixture was heated for several hours at
180C, cooled, and the polymeric product precipitated twice
from methanol. The molecular weight of the resulting
silicone copolymer was evaluated by intrinsic viscosity
measurements in chloroform which ranged between 0.55 and
0.70 dl/g.
A ~eries of polyetherimide-silicone copolymer
blends were prepared by di~olving in chloroform, the
commercially available Ultem~ polyetherimide and ilicone
copolymer to produce a solution having 30% by weight of
solids. The blend solutions were ca~t on a glass plate to a
thickness of about lO mil and allowed to 6tand ov rnight.
Th~ cast blend was determined "miscible" if no ha~iness in
the film was evident. The following r~sults were obtained
where Tg is glass transition temperature, "plus" under
miscibility indicates no haziness l'minus" under mi~cibility
indicates haziness in the resulting cast film, and "Wt%
polyetherimide" means the weight of polyeth~rimide, divided
by the weight of the blend x 100%.
Silioone Copolyner Polyetherimide
.
Silioone Copolymer Wt % , T (C)
tle ratio) Polyetherimlde g Miscibility
~ ~~~~ 217
P~D6/~P~MPD (1:1:2) 50 202 +
PA~S/BPAY~MPD " 25 196
PAD6/EpAn~pD " 10 193 +
P~D6/BP~MæD (75:25:100) 50 175,215
P~D6/BPA~D " 2S 175,215
PAD6/~PA~MPD/PPD (1:1:1:1) 50 210
PALS/BPAn~4MPD/P~D (50:50:75:25) 50 203
RD-17,873
13228~2
The above results show that major amounts of
silicone copolymer can be blended with poly~therimide
without substantially affecting the Tg of the
polyetherimide. It was also found that blends having a
range of 5% to 95% by weight of silicone copolymer can
exhibit substantially the same Tg as shown for 50% by weight
of silicone copolymer. In instances where silico~ne
copolymer having a 3 to 1 mole ratio of PADS to BPADA was
blended with polyetherimide, the blend was ound to be hazy.
The hazy blends showed a T~ for the silicone copolymer and a
~eparate Tg for the polyetherimide.
Although the above example is directed to only a
few of the very many variables which can be employed in the
practice of the present invention, it should be understood
that the present invention is directed to a much broader
variety of blends of polyetherimides and ~ilicone polyimides
as shown in the description preceding this example.
