Note: Descriptions are shown in the official language in which they were submitted.
~3~3~
Mo-2456
PC~ 6
OLYCARBONATE BLENDS HAVING LOW GLOSS
FIELD OF THE INVENTION
The present invention is directed to a thermo-
plastic molding composition and, more par~icularly, to
a composition comprising a polycarbonate resin and a
gra:ft eopolymer.
SUMelARY OF THE INVENTION
The thermoplastic molding compositions of the
invention comprising an aromatic polycarbonate resin, a
graft copolymer of acrylonitrile-butadiene-styrene and
an elastomeric impact modifier are characterized by
their properties including the combination of low
gloss, high ultimate strength and high impact strength
at low temperatures.
_ KGROUND OF THE INVENTION
Compositions containing a blend of polycar-
bonate and ABS were disclosed in U S. Patents 3,130,177
and 3,852,393. Similar compositions were disclosed in
~ U.S. Patents 3,954,905 and 3,988,389 to possess
; 20 improved weld line strength.
Improved impact strength of polycarbonates by
the incorporation of a graft elastomer has been the
subject of numerous U.S. Patents, for instance,
4,299,928, 4,245,058, Re. 28,723, 4,263,4167 4,263,415,
4,260,693 and 4,G82,895 among others.
In some applications, notably power tool
housing, business machine enclosures and automotive
parts, the design requirements limit the permissible
degree of gloss while at the same time specify a high
degree of resistance to impact, especially as expressed
in a relatively low sensitivity to notch effects.
~o-2456
~ ' ~
~3~;~3~
--2--
The present invention discloses thermoplastic
compositions eminently suitable for these applications.
Gloss, as a material property, is determined
in accordance with ASTM D~528, Standard Method of Test
for Specular G]oss.
DETAII,ED DESCRIPTION OF THE INVENTION
.
The Polycarbonate Resin
The polycarbonate resins useful in the
practice of the invention are homopolycarbonates, co-
polycarbonates and terpolycarbonates or mixtures there-
of. The polycarbonates generally have molecular
weights of 10,000-203,000 (average molecular weight),
preferably 20,000-80,0Q0 and may have a melt flow rate
per ASTM D-1238 at 300C of about 1 to about 24 gm/10
min., preferably about 2-6 gm/10 min. They may be
prepared, for example, by the known diphasic interface
process from a carbonic acid derivative such as phos-
gene and from dihydroxy compounds by polycondensation
see German Offenlegungsschriften 2,063,050; 2,0~3,052;
1,570,703; 2,211,956; 2,211,957 and 2,248,817; French
Patent 1,561,518; and the monograph H. Schnell, "Chemis-
try and Physics of Polycarbonates", Interscience
Publishers, New York, 1964.
In the present context, dihydroxy compounds
suitable for the preparation o~ the copolycarbonates of
the invention conform to the structural formulae (1) or
(2)
Mo-2456
=:
,~'g <~o~ (1)
: (Z)d (z)d e H~ OH (2)
( )f (z)f
wherein
A denotes an alkylene group with 1 to ~ carbon atoms,
an alkylidene group with 2 to 8 carbon atoms, a cyclo-
5 . alkylene group with 5 to 15 carbon atoms, a cycloalkyli-
dene group with 5 to 15 carbon atoms, a carbonyl group,
an oxygen atom, a sulfur atom, an -SO- or -S02~
radical; or a radical conforming to
~H3
C H 3 ~C or C ~ CH 3
CH3 CH3 CH3
e and g both denote the number 0 to 1;
Z denotes F, Cl, Br or Cl-C4-alkyl and if several Z
radicals are substituents in one aryl radical, ~hey may
be identical 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, bis-
(hydroxyphenyl~-alkanes, bis-~hydroxyphenyl)-ethers,
bis-(hydroxyphenyl)-ketones, bis-(hydroxyphenyl)-
sulfoxides, bis-(hydroxyphenyl)-sulfones and ~, ~-bis-
(hydroxyphenyl~-diisopropyl-benzenes, as well as their
Mo-2456
:
--4--
nuclear-alkylated compounds. These and further
suitable aromatic dihydroY~y compounds are described,
for example, in U.S. Patents 3,028,365; 2,999,835;
3,1~8,172; 2,991,273; 3,271,367; and 2,999,846.
Further examples of suitable bisphenols are 2,2-bis-(4-
hydroxyphenyl)-propane (bisphenol-A), ~,4-bis-(4-
hydroxyphenyl)-2-methyl-bu~ane, 1,l~bis-(4-hydroxy-
phenyl)-cyclohexane, ~,~-bis-(4-hydroxyphenyl)-p-diiso-
propyl-benzene, 2,2-bis-~3-methyl-4-hydroxyphenyl)-
propane, 2,2-bis-(3-chloro-4-hydroxyphenyl)-propane,
bis-(3,5-dimethyl-4-hydroxyphenyl)-methane, 2,2-bis-
(3,5-dimethyl-4-hydroxyphenyl)-propane, bis-(3,5-di-
methyl-4-hydroxyphenyl)-sulfoxide, bis-(3,5-dimethyl-4-
hydroxyphenyl)-sulfone, hydroxybenzophenone, 2,~-bis-
(3,5-dimethyl-4-hydroxyphenyl)-2-methylbutane, l,l-bis-
~3,5-dimethyl-4-hydroxyphenyl)-cyclohexane, a~ -bis-
(3,5-dimethyl-4-hydroxyphenyl)-p-diisopropyl-benzene
and 4,4' sulfonyl diphenyl.
Examples of particularly preferred flromatic
bisphenols are 2,2-bis-(4-hydroxyphenyl)-propane, 2,2-
bis-(3,15-dimethyl-4-hydroxyphenyl)-propane and 1,1-
. bis-(4-hydroxyphenyl)-cyclohexane.
The most preferred bisphenol is 2,2-bis-(4-
~ hydroxyphenyl)-propane (bisphenol-A).
: 25 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 poly-
carbonate copolycarbonates and terpolycarbonates such
as are described in U.S. Patents 3,036,036 and
4,210,741.
Mo-245~
~3~3~
The polycarbonates of the invention may also
be branched by incorporating small quantities of poly-
hydroxyl compounds in them by condensation, e.g., 0.05-
2.0 mol % (based on the quantity of bisphenols used).
Polycarbonates of this type have been described, for
example, in German Offenlegungsschriften 1,570,533;
2,116,974 and 27113,374; Bri~ish 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-tri-(4-hydroxyphenyl~-heptane-2; 4,6-dimethyl-
2,4,6-tri-(4-hydroxyphenyl)-heptane; 1,3,5-tri-(4-
hydroxyphenyl)-benzene; l,l,l-tri-(4-hydroxyphenyl)-
benzene; l,l,l-tri-(4-hydroxyphenyl)~benzene; 1,1,1-
tri-(4-hydroxyphenyl)-ethane; tri-(4-hydroxyphenyl)-
phenylmethane; 2,2-bis-[4,4-(4,4'-dihydroxydiphenyl~-
cyclohexyl]-propane; 2,4-bis-(4-hydroxyphenyl-4-iso-
propyl)-phenol; 2,6-bis-(2'-dihydroxy-5'-methylbenzyl-
4-methylphenol; 2,4-dihydroxybenzoic acid; 2-(4-hydroxy-
phenyl)-2-(2,4-dihydroxyphenyl)-propane and 1,4-bis-
(4'4"-dihydroxytriphenylmethyl) benzene. Some of the
other polyfunctional compounds are 2,4-dihydroxybenzoic
acid, trimesic acid, cyanuric chloride and 3,3-bis-(4-
hydroxyphenyl)-2-oxo-2,3-dihydroindole.
In addition to the polycondensation process
mentioned above and which essentials are described
below~ other processes for the preparation of the poly-
carbonates of the invention are polycondensation in a
homogeneous phase and transesterification. The
suitable processes are disclosed in U.S. Patents
3,028,365; 2,999,846; 3,153,008 and 2,991,273.
Mo-2456
j,
. .'~,
-6-
The preferred process for the preparation of
polyrarbonates is the in~erfacial 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 resins are available in
commerce, for instance, under the tradename Merlon*
M-39, Merlon* M-40 and Merlon* M-50, all of which are
bisphenol-A based pulycarbonate resins differing in
their respective molecular weights and characterized in
that their melt indices per ASTM D-1238 are 12-24,
6-11.9 and 3.0-5.9 gm/10 min., respectively, all availa-
ble from Mobay Chemical Corporation of Pittsburgh,
Pennsylvanla.
Graft Copolymers
In the context of the present practice, graft
copolymers are ABS (acrylonitrile-butadiene-styrene~
resins prepared by either bulk or bulk (~ass) sus
pension polymerization (as distinguished from similar
resins prepared by emulsion polymerization) charac-
terized in that their polybutadiene content is about 1
to 25% by weight, preferably 3 to 20% by weight, and in
that its average particle size is greater than 0.75,
preferably bet~leen 0.8 to 15 microns.
Essentially, the molecules of ABS graft poly-
mers consist of two or more polymeric parts of dif-
ferent compositions chemically united. The graft poly-
mers may be prepared by polymerizing at least one con-
jugated diene, such as butadiene or a conjugated diene~ith a monomer polymerizable therewith, such as
* Trademark
Mo-2456
~ '
~'~ L3..
~2~
-- 7
styrene, to provide a backbone, with subsequent polymer-
iza~ion of at least one grafting monomer, and prefer-
ably two, in the presence of the prepolymerized
backbone to complete the graft polymer.
The backbone9 as mentioned, is preferably a
conjugated diene polymer or copolymer such as polybuta-
diene, butadiene-styrene, butadiene-acrylonitrile or
the like.
A specific conjugated diene 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, alkyl groups containing from one to five
carbon atoms, chloro and bromo. Examples of dienes
that may be used are butadiene; isoprene; 1,2-hepta-
diene; methyl-1,3-pentadiene; 2,3-dimethyl-1,3-buta-
diene; 1,3-pentadiene; 2-methyl-3-ethyl-1,3-butadiene;
2-ethyl-1,3-pentadiene; 1,3- and 2,4-hexadienes,
chloro- and bromo-substituted butadienes such as
dichlorobutadiene, bromobutadiene, chloroprene, dibromo-
butadiene, mixtures thereof and the like. The
preferred conjuga~ed diene utilized herein is buta-
diene.
The first monomer or group of monomers
polymerized in the presence of the prepolymerized
backbone are preferably monovinyl aromatic hydro-
carbons. The preferred monovinyl aromatic monomers
utilized are generically described by the formula:
Mo-2456
:,
Y y - 8
Y~l--C\Y
wherein Y may be selected from the group consisting of
hydrogen 9 alkyl groups containing from 1 to 5 carbon
atoms, chloro and bromo. Examples of the monovinyl
aromatic compounds and substituted monovinyl aromatic
compounds that may be used are styrene and other vinyl-
substituted aromatic compounds inclucling alkyl-,
cyclo-, alkyl-, aryl-, alkaryl-, aralkyl-, alkoxy-,
aryloxy-, and other substituted vinyl aromatic
compounds. Examples of such compounds are 3-methyl-
styrene; 3,5-diethylstyrene and 4-n-propylstyrene,
~methylstyrene, ~-methylvinyltoluene, ~-chlorostyrene,
vinyltoluene, ~-bromostyrene, chlorophenyl ethylenes,
dibromophenyl ethylenes, tetrachlorophenyl ethylenes,
l-vinylnaphthalene, 2-vinylnaphthalene, mixtures
; thereof and the like. The preferred monovinyl aromatic
hydrocarbon used herein is styrene and/or ~-methyl-
styrene.
The second group of monomers that are polymer-
ized in the presence of the prepolymerized backbone are
acrylonitrile, substituted acrylonitrile and/or acrylic
acid esters exemplified by acrylonitrile and alkyl
acrylates such as methylmethacrylate. The acrylo~
nitrile, substituted acrylonitrile or acrylic acid
esters are described generically by the formula:
S~
~, ~C - C - z
Mo-2456
, '
~3~3~
~9--
wherein S may be selected from the group consisting of
hydrogen, alkyl groups containing from 1 to 5 carbon
atoms, chloro and bromo and Z is selected from the
group consisting of cyano and carbalkogy wherein the
alkyl group of the carbalkoxy group contains from 1 to
about 12 carbon atoms. Examples of monomers of this
description, i.e., acrylonitrile, substituted acrylo-
nitrile, or acrylic acid esters of the above formula
are acrylonitrile, ethacrylonitrile, methacrylonitrile,
a-chloroacrylonitrile, ~-chloroacrylonitrile, ~-bromo-
acrylonitrile and ~bromoacrylonitrile, methacrylate,
methylmethacrylate, ethylacrylate, butylacrylate 3
propylacrylate, isopropylacrylate, isobutylacrylate,
mixtures thereof and the like. The preferred acrylic
monomer used herein is acrylonitrile and the preferred
acrylic acid esters are ethylacrylate and methylmeth-
acrylate.
In the preparation of the graft polymer, the
conjugated diolefin polymer or copolymer exemplified by
1,3-butadiene polymer or copolymer comprises 1 to 25%
by weight, preferably 3% to 20% by weight, of the total
graft polymer composition and the monomers polymerized
in the presence of ~he backbone e~emplified by styrene
and acrylonitrile comprise about 75 to 99%, preferably
80 to 97% by weight~ of the total graf~ polymer compo-
sition.
Essentially, the ABS resins of the invention,
described more fully in U.S. Patent 3,852,393, are
obtained by dissolving a butadiene type rubber, such as
polybutadiene or a butadiene-styrene copolymer, in a
mixture of a vinyl cyano compound represented, for
Mo-2456
1()-
example, by acrylonitrile and a vinyl aromatic hydro-
carbon (including a halogenated compound~ represented
by styrene, polymerizing the mixture substantially
under bulk polymerization conditions, although a small
amount of ~ater can be present in some cases t under
sufficiently high agitation so as to shear the rubber
being precipitated as polymerization advances until 1
to 40~ by weight of vinyl cyano compound and vinyl
aromatic compound are polymerized.
In the case of bulk suspension, water and a
suspension stabilizer are then added to the polymer-
iza~ion system whereas in the case of the bulk process,
the polymerization continues to a predetermined degree.
Among the grafts suitable in the present
context is an ABS resin available as Dow ABS Resin* 213
from Dow Chemical Company, of Midland, Michigan - see
below a table summarlzing its characteristlc proper-
ties.
*Trademark
Mo-2456
~f,~
;23~3
Property ASTMInjection
MethodMolded
Yield ~ensile Strength
lbf/in D-6384,300
Ultima~e Tensile Strength
lbf/in D-6385,000
Yield Elongation, ~ D-638 2
Ultimate Elongation, % D-638 50
Tensil~ Modulus
lbf/in D-638360,000
Izod Impa~t Strength,
ft lbf/in of Notch
@ i30F D-256 1.8
@ 0F 1.2
@ -40F 1.0
Vicat Softening Point F D-1525 216
Deflection Temperature 2
Annealed F @ 264 lbf/in D 648 200
Flexur~l Strength,
lbf/in D-7909,500
Flexur~l Modulus,
lbf/in D-790380,000
Hardness, Rockwell R D-785 1705
L
Specific Gravity D-792 1.05
Linear Coefficient of Ther- 5
mal Expansion, In/In/F D-6965 x 10
Melt Flow Rate, Cond. I
g/10 min. D-1238 5.5
Particle size range, microns 0.5-10
average microns ~3
Mo-2456
~3~23~
- 12 -
The Impact Modifyin~ Graft
In the context of the present invention, the
impact modifying graft is a rubber elastic based graft
copolymer characterized in that its glass transition
temperature is below 10C, preferably below O~C, and in
that elastomeric content is about 15 to 98%, preferably
from about 20 to about 95~ by weight and in that its
average particle size is less than 0.75 micron.
In the preferred grafts, a monomer mixture
phase of from 95 to 50% by weight of styrene, methyl-
methacrylate or mixtures thereof and from 5 to 50% by
weight of acrylonitrile is graft polymerized onto a
rubber. In principle, any rubber may be used as the
graft backbone so long as its properties meet the
criteria set out above. Cross-linking of the rubber
elastic phase is an optional feature of the impact
modifier graft.
Particularly suitable rubbers are polybuta-
diene, butadiene/styrene copolymers having up to 30% by
weight of copolymerized styrene, copolymers of buta-
diene and acrylonitrile with up to 20% by weight of a
lower alkyl ester of an acrylic or a methacrylic acid
for example, methylacrylate, ethylacrylate, methylmeth-
acrylate and ethylmethacrylate or an acrylate based
rubber such as Cl-C6-alkyl acrylate, preferably a
butylacrylate.
The weight ratio of rubber to graft
polymerized monomers is generally within the range of
from 85:15 to 40:60 and the impact modifier graft must
be present in the molding composition in the form of
particles which diameters may range from about 0.01 to
Mo 2456
-13-
about 5 microns provided, however, that the average
value is less than 0.75 microns.
Graft polymers of this kind are known. They
are obtained, for example, by polymeriging the monomers
on a rubber latex in the presence of a radical
catalyst, and are available in commerce from for in-
stance, Bayer AG of Leverkusen, West Germany.
~ mong the acrylate based grafts are the multi-
phase acrylic rubber interpolymer composites described
in U.S. Patents 3,808,180 and 4,096,202. Briefly, the
technology described therein is that of the preparation
of a specific class of multiphase compounds. These are
compositions comprising about 25 to 95% by weight o-f a
first elastomeric phase and about 75 to 5~ by ~eight of
a second, rigid, thermoplastic phase. The first phase
is polymerized from about 75 to 99.8~ by weight Cl-
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 ~leight of a
cross-linking monomer and to which is added 0.1 to 5
by weight of a graft-linking monomer.
The preferred alkyl acrylate is butyl-
acrylate. The cross-linking monomer is a polyethyleni-
cally unsaturated monomer having a plurality of ad-
dition polymerizable reactive groups all of whichpolymerize at substantially the same rate of reaction.
Suitable cross-linking ~onomers include polyacrylic and
polymethacrylic esters of polyols such as butylene
diacrylate and dimethacrylate, trimethylol propane
trimethacrylate and the like; di- and trivinyl benzene,
vinyl acrylate and methacrylate, and the like. The
Mo-2456
~,.....
- 14 -
preferred cross-linking monomer is butylene
diacrylate. The graft-linking monomer i5 a polyethylen-
ically unsaturated monomer having a plurality of
addition polymerizable reactive groups, at least one of
which polymeri~ing at a substantially different rate of
polymerization 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
lo polymerization and, consequently, at or near the
surface of the elastomer particles. The preferred
graft-linking monomer is allyl methacrylate and diallyl
maleate.
The final stage monomer system can be
comprisecl of Cl-C6-methacrylate, styrene, acrylo-
nitrile, alkyl acrylates, alkyl methacrylate, dialkyl
methacrylate and the like, as long as the over Tg is at
least 20C. Preferably, the final stage monomer system
is at least 50% by weight Cl-C4-alkyl meth-
acrylate. It is ~urther preferred that the final statepolymer be free of units which tend to degrade
poly(alkylene terephthalate); for example, acid,
hydroxyl amino and amide groups.
A certaln such acrylic rubber interpolymer
composite characterized in that acrylic rubber core is
comprised of n-butyl-acrylate and in that its cross-
linking agent is 1,3-butylene diarylate and in which
; the graft-linking agent is diallyl maleate and the
second phase monomeric system of which is methyl meth-
acrylate is noted to be particularly suitable in the
present context.
Mo-2456
:
-15-
The compositional makeup of the preferred
interpolymer compound is described by the weight ratios
of its constituent monomers as follows: n butyl-
acrylate/1,3-butylene diacrylate/diallyl maleate/methyl-
methacrylate - 79.2/0.4/0.4/20Ø
A suitable acrylic rubber interpolymer com-
posite is available under the tradename Acryloid* KM-
330 from Rohm ~ Haas Company of Philadelphia, Pennsyl-
vania.
The thermoplastic molding compositions of ~he
invention comprise a blend containing 20 to 95 phr of
polycarbonate resin, 3 to 78 phr of the graft copolymer
and a 2 to 40 phr of the impact modifying graft; a
corresponding preferred set of ranges is 30 to 80 phr
of polycarbonate, 10 to 60 of the graft copolymer and 5
to 30 of the impact modifying graft.
:[n addition to the components of the compo-
sition of the invention, as noted above, the compo-
sition may contain mold release agents, pigments, dies,
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 composition of the
invention follows a procedure comprising dry blending
of the ingredients followed by extrusion and pel-
letizing by means well established in the art and ex-
emplified below.
The invention will be illustrated but is not
intended to be limited by the Examples below. In all
the examples described below, except where noted other
wise, the graft polymer was Dow ~BS resin 213 and the
polycarbonate resin was a bisphenol-A homopolycarbonate
*Trademark
Mo 2456
F~,7
~;~3~
- 16 -
having a melt flow index of about 6 to 11.9 gm/10 min.
Also, the polybutadiene based impact modifiers
iden~ified as A, C, D and G used in the examples below
were characterized in that their glass transition
temperature is -85C and in that their average particle
size is below 0.4 microns.
EXAMPLES
Examples 1-7
Compositions in accordance wlth the invention
were prepared and their properties determined as is
summarized below in Table 1. The blended components
were extruded (2" MPM-Extruder, Compression ratio
2.75:1, screen pack 20-40-60-20~ at a temperature
profile (rear to front): 270/280/270/255/245/265/
265C. The compositions were injection molded into
test specimens at 450F. In addition to the components
noted in the Table, a thermal stabilizer described
generally in DOS 2,929,229 was incorporated in the
composition at a level of 0.2~. No criticality in the
context o~ the present invention is assigned to the
addition of said stabilizer.
Mo-2456
~,,
3~
TA~3LE 1
Control
1 2 3 4 S 6 7
Polycarbonate, pbw60.060.060.060.060.060.0 60.0
Graft polymer, pbw40.035.030.025.035.030.0 25.0
Impact modifier, pbw
c~ 5.010.015.0 -- ~
D!2) __ __ __ -- 5.0 10.0 15.0
Melt index, gm/
10 min. 13.2 10.7 9.39.5 11.3 10.6 8.4
Gloss( ) low low low low low low some
Impact strength, Izod-
Notched 1/8" r.t. 11.414.013.2 12.1 13.5 13.3 11.9
-20C 2.6 3.4 4.97.6 6.8 7.3 8.q
~30C 1.9 2.9 3.73.8 3.1 7.1 6.5
-40C 2.1 2.3 2.92.~3 3.4 3.5 4.7
Heat deflection
temperature at
26q psi, C 109.4 111.1109.6104.510~.8111 103.9
(1)
C denotes a graft consisting of 20~
polybutadiene and 80~ SAN (So~N ratio 72/28)
(2)
D denotes a graft ccnsisting of 50% poly-
butadiene grafted with 50~ S~N (S/~N ratio 72/28)
(3)
determined by observation.
Mo-2456
~3~3~
- 18 -
EXAMPLES 8-15
Compositions in accordance with the invention
were prepared and their properties determined as is
summarized below in Table 2. The blended components
were extruded (2" MPM-Extruder; compression ratio
2.75:1, screen pack 20-40-60-20) at a temperature
profile of (rear to front) 270/280/270/255/245/265/
265C. The compositions were injection molded into
test specimens at 450F except as noted below. All the
compositions were noted to yield specimens character-
ized by their low gloss.
~10-2456
--19--
T~BLE 2
Control
8 9 10 11 12 13 14 15
Polycarbonate, pbw 60.0 60.060.0 63.1550.0 50.050.050.0
Graft polymer, pbw 30.0 25.030.0 26.3237.5 32.037.532.0
Impact modifier, pbw
A( ) 10.0 15.0 ~ 12.5 18.0 -- --
B( ) -- -- 10.0 10.53 -- -- 12.518.0
Melt index 6.9 5.26.7 5.9 6.9 4.7 6.8 6.2
Impact s-trength,
notched Izod
ft. lb/in.
Specimen~ tested at room temperature
Specimens molded at
450F 1/8" 15.8 16.013.6 12.2 12.3 13.711.710.8
1/4" 10.7 10.710.3 9.7 12.0 9.710.3 8.9
475F 1/8" 12.6 13.612.3 10.8 16.2 13.811.910.2
1~4" 10.0 10.89.9 9.7 10.9 9.8 8.9 8.2
500F 1/8" 13.0 12.612.4 10.9 12.4 12.910.810.4
l/4~ 10.1 10.59.8 9.8 9.7 9.9 9.0 8.6
525F 1/8" 12.1 12.311.6 11.2 13.3 11.910.9 9.5
1/4" 10.3 10.59.5 9.3 9.8 9.9 7.8 7.9
Tested at:
1/8" -20C 7.9 9.68.2 8.4 8.9 8.8 7.2 7.0
-30C 5.8 8.36.0 7.6 6.6 7.6 6.8 5.4
-40C 3.8 7.25.4 6.7 3.4 5.9 4.0 4.8
Mo- ~4 5 6
;;
~'
3~
-- ~o --
TABLE 2-Cont ' d
Control
8 9 10 11 12 13 14 15
Heat deflection
temperature,
C, at 264 psi 115.2 115.1 119.0 116.5 107.0 106.7 109.2 109.8
(1)
A denotes a graft consisting of 80% polybutadiene
grafted with 20% SAN (S/AN ratio being 72/28), the average
particle size is about 0.3 to 0.5 microns.
~2)
B denotes Acryloid KM-653 which is an MBS System (methylmethacrylate
butadiane-styrene copolymer); a product of Rohm & Haas, character-
ized in that the Tg of the rubber phase is below -50C.
Mo-2456
3~31
EXAMPLES 16-19
The compositions noted below were prepared and
tested in much the same way as was described above.
Excep~ for composition 19, a small amount (0.3 pbw) of
a thermal stabilizer of the type described in DOS
2,929,229 was added to the compositions. No
criticality is ascribed to that addition in the present
invention.
Mo-2456
~3~ ,3~
-22-
TABLE 3
Control 16 17 18 19
Polycarbonate, pbw 60.0 60.0 50.0 50.0
Graft polymer, pbw 30.0(a) 40.0( ~ 37.5( ) 37.5( )
Impact modifier
D(2), pbw 10.0 - 12.5 12.5
Melt index,
gm/10 min. 9.2 very high 10.0 9.4
Gloss some high somevery low
Heat deflection
temperature at
26~l psi, C 114.5 113.1 103.2 104.3
Impact strength, Izod
notched, ft.lb/in.
1/8'i r.t.16.3 12.4 15.6 12.4
-20C 9.7 3.8 7.1 9.5
-30C 6.2 1.3 3.6 4.8
-40C 2.9 1.1 2.4 2.7
tl) Novodur* PK - Emulsion ABS, containing 30% poly-
butadiene and 70% SAN (S/AN = 72/28), particle size
average about 0.4 microns, Tg of the rubber phase
is -85C, Commercial Product of Bayer AG.
(2) An impact modifier graft consisting of 50% poly-
butadiene and 50% SAN (S/AN = 72/28).
~a) Dow Chemical ABS resin, 213.
* Trademark
Mo-2456
,~
- 23 -
As may be readily appreciated, the addition of
the impact modifiers of the invention have a most
profound effect on the low temperature impact
performance of the blends of polycarbonate and graft
polymer. This is particularly unexpected in view of
the decline, or at best the marginal improvement, in
room temperature impact strength of these compositions.
The compositions of the invention are further
noted to be of a characteristically low gloss.
E AMPLES 20-24
Further compositions in accordance with the
invention were prepared and their properties determined
as noted below. The blended components were extruded
(ZSK 53, 100-110 rpm, 90~100 lbs/hr) at a temperature
profile (rear to front): 270/250/235/240/235/240C.
The compositions were injection molded at 450F except
as noted.
Mo-2456
~3~;23~
-24-
~ABLE 4
Control 20 2122 23 24
Polycarbonate, pbw 60.0 60.0 60.0 60.0 52 60
Graft polymer, pbw 40.0 30.0 30 0 __ 48(1) 30
Impact modifier, pbw
G (3~ lO.o -_ __ __ __
D ( -- -- 10.024.0 -- --
KM 330 -- -- -- -- -- 10
SAN CN 51 ) -- -- --16.0 -- --
Polybutadiene content
(%) 3.2 9.9 7.412.0 9.0 2.4
Melt Index
~gm/10 min.)12.9 7.5 8.7 6.0 5.2 9.0
HDT a-t 264 psi, C 110.3109.5112.7115.2 113.6 111.2
Gardner impact, in. lb.
room temperature 440 380395354 363 368
a~ -29 292 290 330339344 288
Gloss (60) ~52 45 61.995.6 95.5 68
Ultimate elongation,
% 70.0 120.0120.0100.030.0 110
Notched Izod Impact
(ft.lb./in.) specimens
tested at room temperature
Molded at
450F, 1/8"11.6 13.1 13.211.8 11.3 12.7
1/4" 9.2 10.5 10.410.0 9.2 9.8
475F, 1/8"11.7 12.5 12.811.5 11.3 15.9
1/4" 9.0 10.4 10.5 9.3 8.9 10.4
500F, 1/8"11.3 11.9 12.210.8 9.9 12.3
1/4" 8.8 10.0 10.5 9.4 7.4 11.3
Mo-2456
~3~
-25-
TABLE 4 - Cont.
Control 20 21 22 23 24
525F, 1/8"11.8 11.2 llo9 10~0 8~012~1
1/4"8.7 9.9 g.9 ~.3 3.111.0
Notched Izod
in.lb./ft.
1/8" at ~20C 2.3 12.6 9.9 9.1 7.2 7.5
at -30C1.7 10.8 8.2 7.5 2.7 5.2
at -40C1.3 4.8 5.7 7.9 2.4 3.5
(1) Blendex* 206 - Emulsion ABS, a product of Borg-
Warner - characterized in that its average particle
size is about 0.1 - 0.2 microns and in that its
polybutadienP content is about 18%.
(2) SAN CN Sl - styrene acrylonitrile copolymer - a
product of Monsanto having a S/AN ratio of about
3:1.
(3) denotes an impact modifier graft containing 75%
polybutadiene grafted with 25% SAN (S/AN - 72/28).
The average particle size is about 0.3 ko 0.5
microns.
(4) denotes an impact modifier graft containing 50%
polybutadiene grafted with 50% SAN (S/AN - 72/28).
The average particle size is about 0.3 to 0.5
microns.
*Trademark
Mo-2456
'` L'~
3~3
The results presented in Table 4 clearly
indicate that the compositions in accordance with the
invention, i.e., 20 and 21 feature an attractive
combination of good impact properties, low gloss values
and high ultimate elongation as compared with either
the control or with compositions 22 and 23.
Although the invention has been described in
d~tail in the foregoing for the purpose of illustra-
tion, 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.
Mo-2456
