Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
I
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PC-158
MOLDING COMPOSITIONS CONTAINING
POLYCARBONATE AND A PERTAIN ABS RESIN
FIELD OF THE INVENTION
-
The invention concerns thermoplastic molding
5 compositions and more particularly compositions contain-
in a polycarbonate resin and a conjugated dine graft
polymer.
SUMMARY OF THE INVENTION
The thermoplastic molding composition of the
10 invention comprises a blend of an aromatic polycarbonate
resin, an impact modifier which is characterized in that
it contains at least 45% of an elastomers phase having a
glass transition temperature below 20~C, and a
conjugated dine graft polymer having a 1 to 40~ by
15 weight content of a rubbery backbone wherein the grafted
phase comprises a polymerized mixture of a monovinyl
aromatic monomer and alkali substituted monovinyl
aromatic monomer at a ratio there between from about 30:1
to about 'L:30. The composition of the invention
20 combines improved impact strength and good HUT value.
BACKGROUND OF THE INVENTION
Compositions containing a blend of po'lycarbon-
ate and ABS were disclosed in U.S. Patents 3,130,177 and
3,852~393. Similar compositions were disclosed in
25 U.S. Patents 3,954,905 and 3,988,389 to possess improved
weld line strength.
Improved impact strength of polycarbonates by
the incorporation of a graft elastomers has been the
subject of numerous U.S. patents for instance,
30 4,299,928, 4,245,058, Rev 28,723, 4~263,416, 4,263,415,
4,260,693 and 4,082,895 among others.
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DETAILED DESCRIPTION OF THE INVENTION
The Pot carbonate Resin
y
The polycarbonate resins useful in the practice
of the invention are homopolycarbonates, copolycar-
5 donates and terpolycarbonates or mixtures thereof. Thepolycarbonates generally have molecular weights of
10,000-200,000 (average molecular weight), preferably
20,000-80,000 and may have a melt flow rate per ASTM
D-1238 at 300C of about 1 to about 24 gm/10
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min., preferably about 2-:15 gm/10 min. They may be
prepared, for example, by the known diphasic interface
process from a carbonic acid derivative such as phase
gene and from dihydroxy compounds by polycondensation
(see German Offenlegungsschriften 2,063,050; 2,063,052;
1,570,703; 2,2117956; 2,211,957 and 2,248,817; French
Patent 1,561,518; and the monograph, H. Chenille,
"Chemistry and Physics of Polycarbonates", Intrusions
Publishers, slew York, 1964.
In the present context, dihydroxy compounds
suitable for the preparation of the copolycarbonates of
the invention conform to the structural formulae (1) or
do l (1)
Ho (2)
( Ed ( of
wherein
A denotes an alkaline group with 1 to 8 carbon atoms,
an alkyLidene group with 2 to 8 carbon atoms, a cycle-
alkaline group with 5 to 15 carbon atom, a cycle-
25 alkylidene group wow 5 to 15 carbon atoms, a car-
bony group, an oxygen atom, a sulfur atom, an -SO
or SO2-radical; or a radical conforming to
clue
I c or Clue C
C~13 C113 ._,
e and g both denote the number 0 or 1;
owe
, I. .,
--3--
Z denotes F, Of, By or Cl-Cll-alkyl end if several
Z radicals are substituents in one aureole radical, they
may be iden~lcal or different;
d denotes 0 or an integer of from 1 to 4; and
f denotes 0 or an integer of -from 1 to 3.
Among the useful bisphenols in the practice of
the invention are hydroquinone, resorcinol, Boyce-
droxyphenyl)-alkanes, bis-(hydroxyphenyl)-ethers, bus-
(hydroxyphenyl)-ketones, bis-(hydroxyphenyl)-
sulfoxides, bis-(hydroxyphenyl)-sulfones and Boyce-
(hydroxyphenyl)-diisopropyl-benzenes, as well as their
nuclear-alkylated compounds. These and further
suitable aromatic dihydroxy compounds are described,
for example, in U.S. Patents 3,028,365; 2,999,835;
3,148,172; 2,991,273; 3,271,367; and 2,999,846.
Further examples of suitable bisphenols are Boyce-
hydroxyphenyl)-propane (bisphenol-A), Boyce-
droxyphenyl)-2-methyl-butane, 1,1-bis-(4-hydroxy-
phenyl)-cyclohexane, ~,~-bis-(4~hydroxyphenyl)-p-diiso-
propyl-`~enzene, 2,2-bis-(3-methyl-4-hydroxyphenyl)-
propane, 2,2-bis-~3-chloro-4-hydroxyphenyl)-propane~
bis-(3,5-dimethyl-4-hydroxyphenyl)-methane, Boyce-
(3,5-dimethyl-4-hydroxyph~nyl~-propane~ buzzed-
methyl-4-hydroxyphenyl)-sulfoxide, bis-~3,5-dimethyl~4-
hydroxyphenyl)-sulfone, hydroxybenzophenone, Boyce-
(3,5-dimethyl-4 hydroxyphenyl)-2-methylbutane, l,l-bis-
(3,5-dimethyl-4-hydroxyphenyl)-cyclohexalle, Boyce-
(3,5-dimethyl-4-hydroxyphenyl)-p-diisopropyl Bunsen
and 4l4'-sulfonyl diphenyl.
Examples of particularly preferred aromatic
bisphenols are 2,2-bis-(4-hydroxyphenyl)-propane, 2,2-
bis-(3,15-dimethyl-4-hydroxyphenyl)-propane and 1,1
bi.s-(4-hydroxyphenyl)-cyclohexane.
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The most preferred is 2,2-bis-(4-hydroxy-
phenyl)~propane (bisphenol-A).
The polycarbonates of the invention may entail
in their structure units derived from one or more of
the suitable bisphenols.
Among -the resins suitable in the practice of
the invention are included phenolphthalic-based polycar-
borate, copo]ycarbonates and terpolycarbonates such as
are described in U.S. Patents 3,036,036 and 4,210,741.
The polycarbonates of the invention may also
be branched by condensing therein small quantities,
e.g., 0005-2.0 mow % (based on the quantity of bus-
phenols used) of polyhydroxyl compounds. Polycar-
donates of this type have been described, for example,
15 in German Offenlegungsschriften 1,570,533; 2,116,974
and 2,113,374; British Patents 885,442 and 1,079,821
and U.S. Patent 3,544,514. The following are some
examples of polyhydroxyl compounds which may be used
for this purpose: phloroglucinol; 4,6-dimethyl-2,4,6-
20 tri-(4-hydroxyphenyl)-heptane; 1,3,5-tri-~4-hydroxy-
phenyl)-benzene; 1,3,5-tri-(4-hydroxyphenyl)-benzene;
1,1,1-tri-(4-hydroxyphenyl)-ethane; tri~4-hydroxy-
phenyl)-phenylmethane; 2,2-bis~[4,ll-(4,4'-dihydroxydi-
phenyl)-cyclohexyl~-propane; 2,4-bis-(4-hydroxy-l-iso-
propylidine)-phenol; 2,6-bis-(2'-dihydroxy methyl
benzyl)-4-methylphenol; 2,4-dihydroxy-~enzoic acid;
2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl)-propanno and
1,4-bis-(4',4"-dihydroxytriphenylmethyl)-benzene. Some
of the other polyfunctional compounds are 2,4-dihydroxy--
benzoic acid, trimesic acid, cyan uric chlorideand3,3-bis-(4-hydroxyphenyl)-2-oxo-2,3-dihydroindoowe.
In addition to the polycondensation process
mentioned above and which essentials are described
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--5--
below, other processes for the preparation of the polyp
carbonates of the invention are polycondensatlon in a
homogeneous phase and transesterification. The
suitable processes are disclosed it U.S. Pa-tents
3,028,365; 2,999,846; 3,153,008; and 2,991,273.
The preferred process for the preparation of
polycarbonates is the interracial polycondensation
process.
Other methods of synthesis in forming the
polycarbonates of the invention such as disclosed in
U.S. Patent 3,912,688 may be used.
Suitable polycarbonate resin are available in
commerce, for instance, under the trade names Morton*
M-39, Morton* M-40 and Morton* M-50, all of which are
bisphenol-A based polycarbonate resins differing in
their respective molecular weights and characterized in
that their melt indices per ASTM D-1238 are 12-~4
6-11.9 and 3.0-5.9 gm~l0 min., respectively, all
available from Moray Chemical Corporation of Pills-
burgh, Pennsylvania Conjugated Dine craft Polymer
In the present context conjugated dine graft
polymers are ABS ~acrylonitrile-butadiene-styrene)
types of resins characterized in that their rubbery
backbone (essentially based on polybutadiene~ content
is about 1 to 40% by weight, preferably 3 to 30~ by
weight and in that its grafted phase comprises the
polymerized mixture ox monovinyl aromatic monomers and
alkali substituted monovinyl aromatic monomers
preferably in a weight ratio there between of about 3011
to 1/30.
*Trademark
~10-2497
:, <.~
3 ire
Essentially, the molecules of ABS resins
consist of two or more polymeric parts of different
compositions chemically united. The graft polymers may
be prepared by polymerizing at least one conjugated
dine, such as butadiene or a conjugated dine with a
monomer polymerizable therewith, such as styrenes to
provide a backbone, with subsequent polymerization of
at least one grafting monomer, and preferably two, in
the presence of the prepolymerized backbone to complete
the graft polymer.
The backbone, as mentioned, is preferably a
Con ugated dine polymer or copolymer such as polybuta-
dine, butadiene-styrene, butadiene acrylonitrile or
the like.
A specific conjugated dine monomer which may
be utilized in preparing the backbone of the graft
polymer is generically described by the formula:
x x x x
C = C - C = C
wherein X may be selected from the group consisting of
hydrogen, halogen, alkyd groups containing from one to
live carbon atoms, sheller and broom. Examples of
dines that may be used are butadiene; isoprene;
1,2-heptadiene; methyl-1,3-pentadiene; 2,3-dimethyl-
1,3-butadiene; 1,3-pentadiene; 2-methyl-3-ethyl-1,3-
US butadiene; 2-ethyl-1,3-pen~adiene; 1,3- and 2,4-hexa-
dines; sheller- and bromo-substituted butadienes such
as dichlorobutadiene, bromobutadiene, chloroprene,
dibromobutadiene, mixtures thereof and the like. The
preferred conjugated dine utilized herein is
butadiene.
The grafted phase, polarized in the presence
of the prepolymerized backbone is characterized in that
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it comprises a mixture of monomers containing at least
one member of each of groups I) and (ii) and option-
ally one or more members from group (iii):
(it monovinyl aromatic monomers conforming to
the formula if x / Ye
wherein Yule independently denote I. hydrogen,
chlorine or bromide atom or a Cluck alkyd group and
X denotes a hydrogen, chlorine or bromide atom.
Examples of this compound include styrenes as well as
alkyd, cycloalkyl aureole, alkaryl, aralkyl, alkoxy and
airlocks substituted vinyl aromatic compounds. Prefer-
ably, the suitable compounds are styrenes 3-methyl-
styrenes 3,5-diethylstyrene and 4-n-propylstyrene,
~-chloros~yrene, vinyltoluene, ~bromostyrene, sheller-
phenol ethylene, dibromophenyl ethylene, tetrachloro-
phenol ethylene l-vinylnaphthalene, 2-vinylnaphthalene
and mixtures thereof. The most preferred compound in
this group is styrenes
(ii) alkali substituted monovinyl aromatic
monomers conforming to Ye
ye lo at yule
lay YO-YO
wherein Yule, independently are a hydrogen,
chlorine or bromide atom or a Cluck alkyd group and
Al is a Cluck alkyd group, for instance a methyl
group;
(iii) acrylonitrile, substituted acrylonitrile
and/or acrylic acid esters exemplified by acrylonitrile
~10-~497
I
and alkyd acrylates such as methylmethacryla~e. The
acrylonitrlle, substituted acrylonitrile or acrylic
acid esters are described generically by the Formula
Y Yo-yo
15-C = C - Z
Yo-yo
wherein YO-YO independently may be selected from
the group consisting of hydrogen, alkyd groups con-
twining from 1 to 5 carbon atoms, sheller and broom and
Z is selected from the group consisting of cyan and
carbalkoxy wherein the alkyd group of the carbalkoxy
group contains from 1 to about 12 carbon atoms.
Examples of monomers of this description, i.e., acrylo-
nitrite, substituted acrylonitrile, or acrylic acid
esters of the above formula are acrylonitrile, ethacryl-
onitrile, methacrylonitrile, ~-chloroacrylonitrile,
~-chloroacrylonitrile, ~-bromoacrylonitrile and Brigham-
acrylonitrile, methacrylate, methylmethacrylate, ethyl-
acrylate, butylacrylate, propylacrylate, isopropyl-
acrylate, iso`butylacrylate, mixtures thereof and the like. The preferred acrylic monomer used herein is
acrylonitrile and the preferred acrylic acid esters are
ethylacrylate and ~ethylmethacrylate.
The butadiene graft polymer used in the course
of demonstrating the invention in the working examples
below, hereinafter "M-ABS" is characterized by its
"approximate" chemical composition as follows: Polyp
butacliene, about 15%; acrylonitrile, about 23%;
styrenes about 487D; and methyl styrenes about 14%.
It
The impact modifier suitable in the practice
of the invention are compounds characterized in that
they contain at least 45 percent, preferably about 45
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to about 98 percent of an elastomeric phase, said
percent being relative to the weight of the modifier
and further in that the glass transition temperature of
the elastomeric phase is below 20C, preferably below
10C. In principle, any rubber may be used as the
elastomeric component of the impact modifier so long as
its properties correspond to the criteria set out
above. Cross-linking of the rubber elastic phase is an
optional feature of the impact modifier. Among the
suitable rubbers are homopolyacrylates and copolyacrv-
fates as well as polymers of conjugated dines and
copolymers of conjugated dines.
Particularly suitable rubbers are polybuta-
dine, butadiene copolymers having up to 30~ by weight
of copolymerized styrenes or acrylonitrile and
copolymers of butadiene with up to 20~ by weight of a
lower alkyd ester of an acrylic or a methacrylic acid
for example, methacrylate, methylmethacrylate and ethyl-
methacrylate as well as bottle or ethyl acrylate; also
suitable are any of the acrylate based rubbers such as
Cl-C~-alkyl acrylate, preferably a butylacrylate.
The rubbers in the context of the invention
may have grafted thereto a "shell" - or a grafted phase
- comprising the polymerized product of one or more
monomers. The weight ratio between the rubber to the
graft polymerized monomers of such embodiments it
generally within the range of from 85:15 to about
45:55.
Grafted impact modifiers of this type are
known. They may be obtained, for example, by pullers-
in the monomers on a rubber late in the presence of a
radical catalyst and are available in commerce, for
instance, from Bayer A of Leverkusen, West Germany.
Lowe
-10 -
Other suitable grafts are available under the
trademark Kane Ace B56, an MOBS (methacrylate-
butadiene-styrene) from Kingfish of Osaka 9 Japan and
various other ABS resins.
Among the acrylate based grafts are the multi-
phase acrylic rubber inter polymer composites described
in U.S. Patents 3,808,180 and ~,096,202. Briefly, the
technology described therein is that of the preparation
of a specific class of multi phase compounds. Among
these, the compositions suitable in the present context
are the ones comprising about 45 to 95~ by weight of a
first elastomeric phase and about 55 to 5% by weight of
a second, rigid, thermoplastic phase. The first phase
is polymerized from about 75 to 99.8~ by weight Of-
C6 acrylate resulting in an acrylic rubber core
having a glass transition temperature below about 10C,
which is cross-linked with 0.1 to 5% by weight of a
cross-linking monomer and to which is added 0.1 to 5
by weight of a graft-linking monomer.
The preferred alkyd acrylate is bottle
acrylate. The cross-linking monomer is a polyp
ethylenically unsaturated monomer having a plurality of
addition polymerizable reactive groups all of which
polymerize at substantially the same rate of reaction.
Suitable cross-linking monomers include polyacrylic and
polymethacrylic esters of polyols such as battalion
diacrylate and dimethacrylate, trimethylol propane
trimethacryLate and the like; dip and trivinyl Bunsen,
vinyl acrylate and methacrylate, and the like. The
preferred cross-linking monomer is battalion dip
acrylate. The graft-linking monomer is a polyp
ethylenically unsaturated monomer having a plurality of
addition polymerizable groups, at least one of which
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- 11 -
polymerizing at a substantially different rate of polyp
merization from at least one other of said reactive
groups. The function of the graft-linking monomer is
to provide a residual level of unsaturation in the
elastomeric phase, particularly in the latter stage of
polymerization and, consequently, at or near the
surface of the elastomers particles. The preferred
graft-linking monomer is ally methacrylate and Delilah
Malta.
The final stage monomer system can be
comprised of Cluck methacrylate, styrenes acryloni-
trite, alkyd acrylates, alkyd methacrylate, dialkyl
methacrylate end the like, so long as the Tug is over at
least 20C. Preferably, the final stage monomer system
is at least 50% by weight Cluck alkyd mutt-
acrylate. It is further preferred that the final stage
polymer be free of units which tend to degrade polyp
(alkaline terephthalate); for example, acid, hydroxyl
amino and aside groups.
A curtain such acrylic rubber inter polymer
composite characterized in that acrylic rubber core is
comprised of n-butyl-acrylate and in that its cross-
linking agent is battalion diary late and in which
the graft-linking agent is dlallyl Molly and the
second phase monomeric system of which is methylmeth-
acrylate is noted to be particularly suitable in the
present context.
The compositional makeup of the preferred
inter polymer compound ix described by the weigh ratios
of its constituent monomers as follows: n-butyl
acrylatell,3-butylene diacrylate/diallyl ulaleate/methyl-
methacrylate - 79.2/0.4/0.4/20Ø Such preferred
acrylic rubber interpol~ner composite is available
under the trade name Acryloid~KM-330 from Room & Haag
Company of Philadelphia, Pennsylvania.
oily
- 12 -
Included among the suitable impact modifiers
are JIBS (methacrylate-butadiene-s~yrene grafts) and ABS
(acryloni~rile-butadiene-styrene grafts) resins.
The thermoplastic molding compositions of the
invention comprise a blend containing 20 to 95 phi of
polycarbonate resin, 3 to 78 phi of the graft polymer
and 2 to 20 phi of the impact modifier; a corresponding
preferred set of ranges is 30 to 80 phi of polycarbon-
ate, 10 to 60 phi of the graft polymer and 5 to 15 phi
of the impact modifier.
Among the advantages offered by the compost-
lions of the invention are thermal stability in combine-
lion with good impact resistance and heat deflection
under load. For instance, the degree of thermal
stability may by appreciated upon considering the HUT
value (under ~64 psi) of greater than 110C and a
notched Issued impact strength (1/4" specimens, per ASTM
D-256) of higher than 5.0 ft. lb./in. associated with
specimens molded at about 525F.
In addition to the components of the compost-
lion of the invention, US noted above, the composition
may contain mold release agents pigments, dyes, flame
retardants, stabilizers to heat and moisture as well as
fillers and reinforcing agents of the types known in
the art.
The preparation of the composi~icn of the
invention follows a procedure comprising dry blending
of the ingredients followed by extrusion and pullets-
in by means well established in the art and example-
fled below.
The invention will be illustrated but is not intended to be limited by the Examples below.
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EXAMPLES
Examples 1-5
Compositions in accordance with the present
invention were prepared and a summary of their
properties is presented below. In preparing these
compositions, the polycarbonate resin was a homopoly-
carbonate based on bisphenol-A, characterized in that
its melt index was between 3.0 to 5.9 gm/10 min. The
impact modifiers used were Acryloid KM 330 - a product
of Room and Hays Corporation - which is an acrylate
rubber graft characterized in that its rubber content
is about 80 percent and Acryloid~M 653 - also a
product of Room and Hays Corporation - which is a graft
polymer of methylmethacrylate-butadiene-styrene kirk-
terraced in that its polybutadiene content is about pursuant, and in that its styrenes content is about 13
percent and its methylmethacrylate content is about 14
percent; the indicated polybutadiene based impact
modifiers are characterized both in their polybutadiene
content and their SAN graft wherein the ratio between
styrenes and acrylonitrile was 72/28. The graft polymer
used was "MISS'. After a thorough mixing, the blend,
consisting of the indicated components, was extruded on
a twin screw SKYE 53) at a screw speed of Lowe rum
at a temperature profile of (r Jo I
270/250/235/240/235/240C at a rate of 90~100 lbs/hr.
The amounts of the components are indicated in percent
by weight.
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I lo
--14--
N ¦ O O O 00 Cry O I O
Lo _ I I I I OWE O _
N O O O it aye O
Jo Cal JO O I I I I O OX O
O O O O _ I
_ I O _ _
O O to O to U`\ Us O O CO to
O O O It Us O
to Id C
^ V
C C `_
W W C
O I Jo Ed--
,., p, c , a Q o us Jo
V
2 h I N --' O
My -2497
` to to
Al _ O O _
us I urea
Us Us _ Jo
O
I
o o o o `* ?
_ . . . -
Us
o
JO O
J
o
Jo r_ It o o JO
I It U
I: D rl
O ox o ox o us I q)
CJ Jo o so Kiwi
Us Us _
Us
^ a
'd
us ox o o I
- ox I-
` JO I 0
Lo O Q
o no S to O I
h
:~~ O ::) ¢ ^
o o Us
h o o oh
d v O
a I
ox Jo o
v I I two
ox I
o Jo
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-16-
It is perhaps instructive -to note that the
heat deflection temperature of a composition differing
from Example 1, above, only in that its graft copolymer
contains no methyl styrenes is about 106C.
S Examples 6-13
Further compositions in accordance with the
invention were prepared and a summary of -their
properties is presented below. The components used in
this series of examples were the same as the ones used
in the source of the preparation of the composition of
Examples 1-5, The added impact modifying agent was
Acryloid~ KM653. Extrusion of the dry blended come
pennants was carried out (2" MUM - extrude, compression
ratio 2.75:1, screen pack 20-40-60-40-20) at a temper-
azure profile of (rear to front)
270/280/270/255/245/265/265C.
My 2497
Jo !,',
--1 I
o o o ox CO Jo o Cal
, . . .... ...
O O O o ox D O
_
-
o o o o Us _ _
I o o o o _ ox
.
..
o o o o Us Us Cal o o ,
_ o o o C`J Cry o I o
I ED
I
Al Us
o o o co o cry I) 3
o o o co Ox It I) co a
_ ED it I --I -- I t)
_ ED
o
o O O I I I`-- . o
ox Cal co O o It on us us
Us _ _
o a
Cal O O J o l_ us O
ox I --I v
Us
o o o I It .
O
us _ _ Ed
to I)
.,~ o
I t~l00 1 0 ox I
us I - - o u
a us ¢
U 5 0
o cay
I
_ _
do U C C
V P- w no
o - Hi
æ 5 aye V O C
a Jo a 8
a ) ox o v o o
;'( R I
N O U I.
C Jo Us I
O I O O O ~1 0 0
h a O o U I I I QJ U a
v v o us I O
I) En u U
l. N O (IS o
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The advantages offered by the compositions of the
invention over their prior art counterparts may be
better appreciated upon the consideration O F the follow-
in table.
~10-2497
-- 19 --
P W N I-- Ox I 3 0
Q 9 9 3 V ' Jo -O WOVE N --- n n
3 9 5 I O if)
Pi I- I- W 3 0
3 3 I) Q I> Us S Us 0 ,-- O
3 0 O -h 3
3 3 D -- I 9 to) S
O O W N I Q -
Q Q O 1-- D N
rod Us 3 V- Q
-5 -5 _, _,
Q ox
O O t ' C -- 5 3 __~
to 3 I 3 0
--3' I' -; CO O O g
aye n , I O O
to O I! O 3 -- --O
O _ Jo _.
9 DO to D
O o I U ) 5
~C~C 'C I
Jo Al US 5 C
I Al- to -5 to t Clue
S O I ¦ W ¦ D
Jo S I Al _. I
rut Al n O Jo Q W
O O O O O g
I o --h I r
N Jo mu O
on o --I o I C o
3 US O rut
I I) 3 I
D D So --
Z Z
_. C -- in
D O O O
D D I I O O 3
If 11 0 0 I-- _ O
Jo DO O
N N _, 3 _,
N N O --'I
So 3 I_,
0 0 0 ox
on o o
;:~
; -
- I)
0 0 0 ox
or, I I I
p N
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The compositions Control A, B and C were
prepared using a ASK 53, lo lo rum, Lowe lbs./hr.,
at a temperature profile: 270/250/235/240/235/240C
(rear -to front).
The minor differences between the molecular
weights of the polycarbonates of the control samples
and those of compositions lo 11 and 12, and the differ-
fences between the compounding conditions are not
believed to be critical to the demonstration of the
lo invention.
The data clearly shows that the high tempera-
lure processing of the prior art compositions did not
cause a substantial change in their impact performance
as compared to that of the unmodified blend, i.e. the
blend termed Control A is sufficiently thermally stable
at the processing temperature such that the addition of
an impact modifier thereto has but a minimal effect on
its impact properties. Conversely, the blend of
composition lo is considerably less stable (the cores-
pounding 1j4" impact strength of specimens processed at450QF was By ft.lb./in.) and the improvement attendant
upon the addition of an impact modifier thereto is seen
to be significant and surprising.
Although the invention has been described in
detail in the foregoing for the purpose of illusory-
lion, it is to be understood that such detail is solely
for that purpose and that variations can be made there-
in by those skilled in the art without departing from
the spirit and scope of the invention except as it may
be limited by the claims.
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SUPPLEMENTAL DISCLOSURE
Examples 14-15
An additional unexpected advantage was -found
to be associated with the compositions of the in-
mention. The advantage, in terms of the high level of the mechanical properties of metal plated parts molded
from the composition, is best represented in the table
below. A composition within the scope of the invention
was molded into discs and three thin layers of metals,
(copper, nickel and chromium) deposited therein by
electroless plating. The process for metal plating -
Noviganth 341 by Sphering A of Berlin, FUR, entails
etching, activation, reduction (using an accelerator)
and chemical metal plating (the manner of metal apt
placation and the type of metal being deposited are believed to be immaterial to the invention). A prior
art composition described below as control was likewise
molded and metal plated. m e articles molded from the
composition were evaluated and their properties are
20 reported below
) 15
Control
Polycarbonate(2), 52.Q 52 0
Graft polymer % 38.0 48.0
25 IJnpact Modifier 10.0 --
Gardner Impact, at 73F (in-lbs)
Before plating 370(5) 45~(5)
After plating 27~(5) <~4(6)
~0 Peel strength, 1.0 inch (lobs)
Before thermal suckling 1.45
After thermal. cycling 3.65 2.4
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Notes
(1) The composition contained a small amount of carbon
black having no criticality on the performance of the
composition.
(2) A bisphenol-A based homopolycarbonate hulling a
melt index of about 3-5.9 gm/10 min.
(3) "M-ABS"
(4) An impact modifier containing 75% polybutadiene
grafted with 25% SAN (S/AN = 72/28).
(5) Ductile failure
(6) Brittle failure
(7) In accordance with the -test (GM 4372-M~, the
cycling entailed 10 hours soak at 80C, ho at room
temperature followed by 4 hours at -40C prior to
testing,
As is clearly evident, the composition of the
invention exhibits an improved impact strength no-
tension after plating. Also, the peel adhesion of the
claimed composition was significantly better than that
of the control
Examples 16 -1 ?
Prior art compositions similar in most
respects to the presently claimed invention except for
the absence of the critical -alkyd substitllted moo-
vinyl aromatic monomer from its conjugated dine graft polymer were prepared and evaluated. The table below
summarizes the properties and indicates, by way of a
comparison, the effect of the incorporated impact
modifier in these compositions. As may be apparent
upon a review of the data the addition of an impact
modifier to these compositions does not improve the
impact performance of these compositions. In contrast,
the present invention is predicated in part on the thus
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unexpected improvement in impact performance associated
with the claimed compositions - see compositions 6 and
9 respectively.
16 17
5 Polycarbonate, % 52 52
Graft polymer % 48 38
Impact modifier % -- 10
Issued impact strength, Notched
(ft.lb/in) specimens molded at
10450F 1/8" 14.5 11.4
l/4" 10.1 8.4
525F 1/8" 11.1 9.7
1/4" 8.3 I
Heat Distortion Temperature
await 261 psi, C 105 105
(1) ABS containing no -methyl styrenes
(2) Polybutadiene 75% grafted with SAN (S/AN = 72/28).
Although the invention has been described in
detail in the foregoing for the purpose of thus-
traction, it is to be understood that such detail is solely for that purpose and -that variations can be made
therein by those skilled in the art without departing
from the Sprite and scope of the invention except as it
may be limited by the claims.
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