Note: Descriptions are shown in the official language in which they were submitted.
8CH-2143
~087791 -:
This invention relates to thermoplastic molding com-
positions of a polyphenylene ether resin, a styrene resin
and a radial teleblock copolymer of a vinyl aromatic compound
and a conjugated diene. The compositions of this invention
provide molded articles having good mechanical properties,
including improved impact resistance.
Background of the Invention.- Polyphenylene ether resins
comprise a class of thermoplastics which are characterized
by outstanding physical properties, including hydrolytic
11 8C~-2143
_ :l.Q~'7791
1 stability, e~cellent diele~tic properties, broad temperature
2 use range and dim~nsional stability at elevated temperatures.
3 They can be made by a variety of catalytic and non-catalytic
4 processes from the corr~spondin~ phenols or reactive derivatives
thereof. In general, they are prepared by the oxidative
6 coupling of a phenolic compound with a complex copper catalyst.
7 By way of illustration, descriptions of the preparation of
8 polyphenylene ether resins are contained in Hay, U.S. 3,306,874
9 and 3,306,875 dated February 28, 1976, and in Stamatoff,
u.s. Patents 3,257,357 and 3,257,358 dated June 21, 1966.
11
12 In the Hay patents, the polypheny ene ether resins
13 are prepared by oxidative couplin~ comprising passing an oxygen-
14 containing ~as throuGh a reaction solution of a phenol and a
metal-amine complex catalyst. In the Stamatoff patents, the
16 polyphenylene ethers are prepared by reacting the corresponding
17 phenolate ion wi~h an initiator, e.g.~ an acid peroxide, in
18 the presence of a complexi~ agent.
19
Disclosures relating to the preparation of polypheny-
21 lene ether resins using metal catalysts whic~ do not inclu~e
22 amines are found in ~ieden et al, U.S~ 3,442,~85 (co~per-
23 amidines)~ Makashio et al, ~.SO 3,~73,257 (metal-alcoholates
24 or m~tal phenGlates), and K~ayashi e~ al,U.S. 3,455,880 1 ;
(cobalt chelates). The preparation of polyphenylene ethers
26 by a non-ca~alytic process, e ~., o:idation r~i.h lead dioY.ide,
27 silver oxide, and ~he lilie, is descri~ed in r~ice et al,
8CH-2143
~087791
U. S. Patent No. 3,382,212 dated May 7, 1968.
The processing of polyphenylene ether resins on in-
jection molding and extrusion equipment is enhanced when the
polyphenylene ethers are combined with styrene resins, e.g.,
crystal homopolystyrene or rubber-modified high-impact poly-
styrenes. These polymers are combinable in a wide range of
proportions, e.g., from 1 to 99 parts of polyphenylene ether
and from 99 to 1 parts of styrene resin. Compositions com-
prising from 10 to 60 parts of polyphenylene ether and 90 to
40 parts of styrene resin offer an especially wide range of
desirable design properties. Such combinations are disclosed
in Cizek, U.S. Pat. No. 3,383,435 dated May 14, 1968. The
thermoplastic compositions disclosed in Cizek can include
a rubber-modified high-impact styrene resin, as well as
a homopolystyrene. High-impact styrene resings are
especially useful in providing polyphenylene ether compositions
which posses good resistance to impact.
; It has now been surprisingly discovered that when
compositions of a polyphenylene ether resin and a styrene
resin are blended with a radial teleblock copolymer of a vinyl
aromatic compound and a conjugated diene, e.g., a styrene-
butadiene radial teleblock copolymer, the resulting compositions
provide molded articles of greater impact strength. The radial
: - ¦ - 8CH-2143
~ 3779~
1 teleblock copolymers o~ the present invention have been found2 to be compatible withg and effecti~e for, compositions o~
3 relatively high polyphenylene ether resin content, e.g~, 50
4 parts by weight or ~ore, and low molecular weight crystal
polystyrene3 as well as compositions of relatively low po~y-
6 phenylene ether resin co~tent, e.gO, 35 parts by weight or
7 less, and high-impact polystyrene.
9 As used hexein, the term "radial teleblock copolymer"
refers to branched pol~rs having segments, or blocks, which
11 are comprised o~ a conjugated diene polymer, blocks of a vinyl
12 aromatic polymer, and a coupling a&ent. Mo e particularly, in
13 the copolymer struçture, several chains of the diene pol~mer,
14 usually three o~ more, exten~ from a coupling agent, with
each chain t~erminating at its other end with a block of the
16 vinyl aromatic polymerO It is generally believed that in-
17 compatibility of the block segments in the radial teleblock
18 copolym2r promotes the formation o a two-phase system with
19 blocks o~ tlle vinyl aromatic polymer coalescing to form dis-
crete re~ions, or "domains". These domains simula~e the effect
21 of cross-links be~een the chains o~ elastomer, and a branched
22 elastomeric network is thus formed comprising blocks of a ccr.-
23 jugated diene polymer, blocks o~ vinyl aroma~ic polymer, and
24 a coupling a~ent.
26 Radial Lelebloc~ copoly~ers are Icnown in the art.
27 For instance, detailed descriptions o~ these materials are
- ¦ 108~91 8CH-2143
1 ¦ given by Marrs et al in ADH~SIV~S AGE, December, 1971, pp.
2 ¦ 15-20 and by Haws et al in RUBBER WORLD, January, 1973, pp.
3 1 27-32
- 4 l
S ¦ Summary of the Invention. - According to the present
6 ¦ invention, there are provided thermoplastic molding compos~tions
7 ¦ which comprise an intimate admixture of:
8 I
9 ¦ (i) a polyphenylene ether resin;
l (ii) a styrene resin; and
11 l (iii) a radial teleblock copolymer of
12 1 a vinyl aromatic compound~ a conjugated diene
13 ¦ and a coupling agent.
14 1
Within the invention broadly described above, the
16 styrene resin component (ii) can be either homopolystyrene or
a rubber-modified high-impact polystyrene. The radial tele-
18 block copolymer (iii) is preferably a branched copoly~er o~
19 styrene and butadiene con~aining a relatively small~ effective
amount of a coupli~g a~ent selected from among epoxidiZ
21 polybutadiene (e g., Oxiron 2000 or Oxiron 2001), SiC14 or
22 mLxtures ~hereof.
` 23 _-
24 Detailed DescriPt~on of ~h2 Invention. - The pol~-
.- 25 phenylene ether resin (i) is preferably one of a family having
26 repeating units represented by the formula:
27
__.... . . .... _.............. ... .. _ .
~: ` l ~ -
¦ 8CH-2143
1 ~08779~
3 (I) ~ =
7 wherein the oxygen ether atom of one unit is connected to the
8 benzene nucleus of the next ad~oining unit, n is a positive
9 in'eger and ~s at least 5~, and each Q is a monovalent sub-
stituent selected from the group consisting of hydrogen,
11 halogen, hydrocarbon radicals free of a tertiary alpha-
12 carbon atom, halohydrocarbon radicals having at least ~o
13 carbon atoms between the halogen atom and the phenyl nucleus,
14 hydrocarbonoxy radicals and halohydrocarbonoxy radicals having
a~ least two carbon atoms between the halogen atom and the
16 phenol nucleus.
17
18 Examples of polyphenylene ethers corresponding to
the above formula can be found in the above-referenced patents
of Hay and Stamatoff.
21
22 For purposes o~ the present invention an es~ecially
23 preferred family of polyphenylene ethers includ~s those havi~g --~
24 al~yl substitution in the two positions ortho ~o t~le oxygen
ethcr atom, i.e., those of th2 above formula W;l~ ein e~ch Q
26 is alkyl, most preferably having from 1 to 4 carbon atoms.
27 Illustrati~e members of this class are: poly(2,6-di~cthyl-
. - . 8CH-2143
I iO87791
¦ 1,4-phenylene)ether; poly(2,6-diethyl-1,4-phenylene)ether; poly
2 1 (2~methyl-6-ethyl-1,4-phenylene)ether; poly(2~methyl-6-propyl-
3 ¦ 1,4-phenylene)ether; poly(2,6-dipropyl-1,4-phenylene)ether; poly
4 ¦ (2-çthyl-6-propyl-1~4-phenylene)ether; and the like. The most
S preferred polyphenylene ether resin is poly(2~6-dimethyl-1,4-
6 phenylene)ether, pre~erably having an ~ntrinsic visco~ity of
7 about 0.5 deciliters per gram as measured in chlorofonm at 30C.
9 The prefesred styrene resins (ii) will be those
havin~ a~ least 25Z by weight of repeatin~ units derived
11 from a vinyl aromatic compound of the formula:
17
18 wherein R is hydrogen, (l~wer) all~l or halogen; Z is ~inyl,
19 halogen or (lower) alkyl; and p is 0 or an integer of frDm
21 1 to the number o~ replaceable hydrogen atoms on the benzene
22 nucleus. Herein, ~he term "(lower) alkyl" is intended to mean
alkyl of from 1 to 6 carbon atoms.
24
Merely by way of iilus~ration, such s~yrene resins
225 will include homopolymers such as polystyrenc and monochloro-
27 polystyrene, the modified polystyrenes, such as rubber-modified,
hi&h-impact polystyrene and the styrene cont~ining copolymers,
8CH-2143
1087'79~
1 such as the styrene-acrylonitrile copolymers, styrene-butadiene
2 copolymers, styrene-acrylonitrile- Ç-alkyl styrene copolymers,
3 styre~e-acrylonitrile-butadiene copolymers, poly- ~-methyl-
4 styrene, copolymers of ethylvinylbenzene, and divinylbenzeDe,
styrene-maleic anhydride copolymers, styrene-butadiene-styrene
6 block copolymers and styrene-butadiene block copolymers~ and
7 styrene-butadiene-styrene maleic anhydride block copolymers.
9 Especially preferred styrene resins are homopolystyrene
and rubber-modified high~impact polystyrene resins, i.e., those
11 which have been modified by natural or synthetic polymeric
12 materials which are elastomers at room temperature, e.g., 20
13 to 25C., such as polystyrene resins containing polybutadiene
14 or rubbery styrene-butadiene copolymers. .
16 A preerred hi&h impact polystyrene is FG 834,
17 a~ailable from Foster-Grant Co., which is a rubber-modified
high-impact polystyrene containin~ about 8% polybutadiene
19 rubber. A preferred low molecular wei~ht homopolystyrene
is XPTL-5, commercially a~ailable from Sinclair-Koppers Co.,
21 having a number avera~e molecular weight of about 40,000.
22 A prererred homopolystyrene of relatively hi&h molecular weight
23 is DYL8G, with a number average molecular weicht of about
: - 150,000, also available ~rom Sinclair-Koppers.
26 The radial teleblock copolymers (iii) are availa~le
27 commercially or can be prepared`by following the teachings of
- 8 -
~ : ¦ 8CH-2143
1(:~8779~
1 the prior art. As an illustration, they can be m2de by poly-
2 merizing conjugated dienes, e.g., butadiene, and ~inyl aromatic
3 compounds, e.g., styrene in the prese~ce of an organometallic
4 initiator, e.g., n-butyllithium, to produce copolymers which
contain an active metal atom, such as lith~um, on one end of
6 each of the polymer chains. These metal atom-terminated polymers
7 are then reacted with a coupling agent which has at least three
8 active sites capable of reacting with the carbon-metal atom
9 bonds on the polymer chains and replacing the metal atoms on
the chains. This resultæ in polymers which have relativel~
11 long branches which radiate from a nucleus formed by the poly-
12 functional coupling agent.
13
14 Such a ~ethod of preparation is described in detail
16 in Zelinski et a~, U.S. 3,281,383 dated October 25, 1966.
17
18 The couplin~ agents for the radial teleblock copoly-
19 mers can be chosen from amon& polyepoxides,~polyisocyanates,
polyimines, polyaldehydes, polyketones, polyanhydrides, poly-
21 esters, polyhalides and the like. These materials can con~ain
22 ~wo or more types of functional grou~s~ such as the combinati~n
23 of epoxy and aldehyde ~roups or ~socyanate and halide groups.
24 The couplin~ agents are described in detail in the ab~ve-
~ntioned U~SO 3,281,383
26
27 The conjuga~ed dienes of the radial teleblock copolymer
Il _g_
~ ~ 8CH-2143
10~7791
1 include compounds such as 1,3-butadiene, isoprene, 2,3-dimæthyl-
2 1,3-butadiene, 1,3-pentadiene, 3-buty1-1,3-octadiene, and ~he
- like. The vinyl aromatic polymers may be prepared from vinyl
4 aromatic compounds of Formula II. They include styrene, 1-
vinylnaphthalene, 2-vinylnaphthalene and the alkyl, cycloalkyl,
6 aryl, alkaryl and aralkyl deri~Tatives thereof. Examples include
7 3-methylstyrene, 4-n-propylstyrene, 4-cyclohexylstyrene, 4-
8 dodecylstyrene, 2-ethyl-4-benzylstyrene, 4-p-tolylstyrene,
4-(4-phenyl-n-butyl) styrene, and the like.
In preferred compositions, the radial teleblock copoly-
11 mer will be a radial teleblock copolymer of styrene and butadiene
, 12 with terminal blocks derived from styrene, and a coupling agent
13 selected from epoxidized polybutadiene, SiC14 or mixtures thereof
14 Especially preferred epoxidized polybutadiene coupling agents are
availa~le commercially under the trade names oxiron 2000 and
16 Oxiron 2001.
17 The molecular weight of the radial teleblock copoly-
18 mer and the ratios of the co-monomers thereof can vary broadly.
19 In preferred em~odim2nts the molecular weight of the radial
teleblock copolymer will be from about 100,000 to about 350,000,
21 and will comprise from 1 to 45 parts by weight of the vinyl
22 aroma~c compound and from 99 to 55 parts by weight of the
23 conju~ated diene, based on t~e wei~ht or the radial telebloc~ -'
24 copolymer. The amount of coupling agent in the copoly~er ~Jill
~cpend on the particular a,~nt and thc ~.oun~ of or~anometallic
26 initiator used. Generally, relatively small amoun~s or coupling
27 a~ent, e.g., from about 0.1 to 1 part by weight per 100 parts of
.. ~ ~ r~
.- 1087791 8c~-2l43
1 resin are employed.
2 Preferred radial teleblock copolymers are Solprene 406
3 (containing about 60 parts by weight of butadiene units and about
4 40 parts bg weight of styrene units), Solprene 411 (containing
about 70 parts by weight of butadiene units and about 30 parts by
6 weight of styrene units), Solprene 414 (containing about 60 parts
7 by weight of ~utadiene units and about 40 parts by weight of
8 styrene units), Solprene 417 (containing about 20 parts by weight
9 of butadiene units and about 80 parts by weight of styrene units),
and S411P (containing about 70 parts by wei~ht of butadiene units
11 and about 30 parts by weight of styrene units). These materials
12 also include a relatively minor amount of coupling agent, e.g.,
13 less than 1 part by weight of coupling agent per 100 parts of
14 polymer.
Components (i), (ii) and (iii) are combinable in a
16 fairly wide range of proportions. Preferably, the compositions
17 of this invention will comprise from about 10 to about 65 parts
18 by weight of polyphenylene ether resin (i), from about 90 to
19 ` about 35 parts by weight of styrene resin (ii), and from about
1 to about 25 parts by weight of radial teleblock copolymer
21 (iii), ~ased on the total weight of the composition.
22 The compositions of the invention can also include
23 other ingredients, such as flame retardants, e~tenders, process--
24 in& aids, pi~ments, stabilizers and ~he like, for their con-
ventionally employed purposes, P~einrorcing ~illers, in amoun~s
26 sufficient to impar~ reinforcement, can be used, such as
27 aluminum, iron or nicl;el, and the like, and non-metals, such
~ lt~
1~ 11- I
~ 108~1 ~CH-2143
.1
- as carbon filaments, silicates, such as acicular calcium silicate
2 asbestos, titanium dioxide, potassium titanate and titanate
3 whiskers, glass flakes and fibers.
4 - The preferred reinforcing fillers are of glass. In
general, best properties will be obtained if glass filaments
6 are employed in amounts of from about 10 ~o about 407O by weight,
i based on the combined weight of glass and resin. H~7ever,
s 8 higher amounts can be used.
; g The compositions of this invention can be prepared by
blending the components to form a premix, passing the latter
11 through an extruder at an elevated temperature, e.g., 425 to
j~; 12 640F., cooling and chopping the extrudate into pellets, and
f,'`~ 13 molding them into the desired shape.
14 scription of the Preferred Embodiments. - The
following examples illustrate the compositions of the invention.
~; `
16 They are set forth merely as a further illustrat~on and are not
to be construed as limiting the invention in any manner.
18
19 EXA~LES 1-4
21 Blends of 50 parts by weight or poly(2,6-dimethyl-
22 1,4-phenylene)ether resin, having an intrinsic viscosity of
23 ¦ about 0.5 deciliters per gram as measured in chloroform at
24 ¦ 30C~, 35 parts by weight of a 10~7 molecular ~eight homo-
rolys~yrene (læTL-5, S~nclair-.~o~pers Co.), 15 narts
26 ¦ by wei~ht of a radial teleblock styrene-butadiene
27
~ ~CH-2143
~08779~
1 copolymer (Solprene resins, Phillips Petroleum, See Table 1),
2 1.5 parts by weight of polyethylene processing aid, and 0.5
3 parts by weight of tridecylphosphite, were prepared by blending
4 the components in a Henschel mixer.
The blends contained Solprene 406, Solprene 411,
6 and Solprene 414, respectively. The blends were compounded
on a twin-screw 28 mm Werner-Pfleiderer extruder at a temperature
8 of about 570F. Thereafter the extrudate was chopped into
9 pellets and molded into test bars on a Newbury injection
molding machine.
11 For purposes of comparison, a blend was msde of 50
; 12 parts by weight of poly(2,6-dimethyl-1,4-phenylene)ether resin
13 25 parts by weight of a low molecular weight homopolystyrene
14 (KP~L-5, Sinclair-Koppers Co.), 25 parts by weight of a rubber-
modified high-impact polystyrene ~FG 834, Foster-Grant), 1.5
16 parts by weight of polyethylene and 0.5 parts by wei~ht of
17 tridecylphosphite were prepared as above.
18 Test bars of the compositions were evaluated for phy-
19 sical properties according to AST~I procedures. Heat Deflection
Temperature was measured using 2 1/2 inch x 1/2 inch x 1/8 inch
21 test bars under 264 psi riber stress, Izod I~pact Strength using
22 2 1/2 i~ch x lJ2 inch x 118 inch test bars, Gardner Impact
23 Strength using 3 3/4 inch x 2 112 inch x lJ8 inch test bars, -~
24 Tensile properties CElongation, Tensile Strength at Yield, Ten-
sile Strength at ~reak) using 2 112 inch x 1/8 inch L^type
26
27
8CH-2143
`1~)8779~
tensile bars, and Flexural properties (Flexural Stren~th at
2 yield and Flexural Modulus) using 2 1/2 inch x 1/2 inch x 1/8
3 inch test bars.
4 The results are reported in Table 1.
` 5
6 TABIE 1
~;, 7 Compositial
` 8 ProPerties la 2b 3C 4*
'. 9
Heat Deflection (F) 268 270 268 270
Izod Impact
~,, 11 (ft.lbs-O/in.n.) 2.6 2.9 3.1 1.8
~i 12 Gardner Impact
t,,~ 13 (ill.lbs.) 138 132 183 90
Tensile Elongation
"l 14 (%) 57 ~8 67 85
Tensile Yield
16 (psi x 10-2) 101 94 100 109
Tensile Break
17 (psi x 10-2) 87 79 84 91
- 18 Flexural Yield
19 (psi x 1o-2) 51 142 148 165
~lexural 2~odulus
(psi x 10-3~ 351 336 356 403
21
22
23
24 a Solprene 406,a~Tera~,e mol. ~7t. about200,000 - 3009000
b Solprenc 411,a~,~e~a~,e r,lol. w~. about300,C00
26 c Solprene 414,~vera~e mol. wt. abc~ut150,000
27 ¦ * comparison
h -
8CH-2143
~o~79~
1 It is demonstrated from the above that the compositions
2 o~ Examples 1-3, which are in accordance with the invention,
possess superior impact resistance, as meastlred by the Gardner
4 and Izod impact ~ests, ~Jhen compared with the composition of
Example 4.
~ 6
,f 7 EXAMæLES 5-8
r
Blends of 25 parts by weight of poly(2,6-dimethyl-
r`; 10 1,4-phenylene) ether resin, having an intrinsic viscosity o
11 about 0.5 deciliters per gram as measured in chloroform at
12 30C., 65 parts by weight of rubber-modified hi&h-impact poly-
13 styrene (FG 834, Foster-Grant Co.), 10 parts of styrene-buta-
14 diene radial teleblock copolym~r (Solprene resins, seq Table),
1.5 parts of polyethylene, 0.5 parts of tridecylphosphite, 3.0
16 parts of titanium dioxide, and 0.05 parts of carbon black ~7ere
17 prepared by the method described in Examples 1-4.
18
As a comp~rison, a blend of 25 parts of poly(2,6-
dimethyl-1,4-phenylene) ether ~esin, I.V. about 0.5 in CHCl3
21 at 30~C., 75 parts by weight of hih-imp~ct polystyrene (FG 834),
22 1.5 parts by ~eioht of polyethylene, 0.5 parts by weioht of tri-
23 decy~phosphite, 3,0 parts by ~Jeight o~ titanium dio~id~ ~d 0.05-;
24 parts by wei~ht of carbon black was prep~red as ab~ve,
26 The composi~ions were teste~ as above, and the results
27 are reported in Table 2.
..
- 15 - I
Il ! 8CH-2143
-I ~o~7~9~.
1 TABLE_2
2 Composition
3 operties 5a 6~ P 8*
S Heat Deflection (F) 227 224 225 223
6 Izod Imp.
7 (ft.lbs./in.n.) 3-9 3!3 3.6 2.5
Gardner Imp.
8 (in.lbs.at 73F.) 147 140 159 78
9 Sub-zero Gardner
Impact (in.lbs.at
-40F.) 107 78 39 11
11 - Tensile Elongation
12 (%) 56 60 50 49
Tens~le Yield
13 (psi x 1o-2) 67 65 66 70
14 Tensile Break
(ps~ x 10-2) 70 70 70 69
Flexural Yield
16 (psi x 10-2) 87 85 87 86
17 Flexural Modulus
18 (psi x 10-3) 30~ 291 291 330
19
21 -
22 a, b and c are as desi~nated above in Table l.
23 ll * omparison
26
27
~`
8CH-2143
-~1 1087791
1 . EX~*~LES 9-10
3 The following compositions were prepared using the
procedure described in Examples 1-4. All parts are by weight.
~` 6
: 7 Components 9 1O
Poly(2,6-dimethyl-1,4-
phenylene) ether 35 35
S411P radial teleblock
11 copolymer -- 10
12 DYL 8G high molecular
13 weight homopolystyrene -- 55
FG 834 rubber-modified
14 high-impact polystyrene65 --
Triphenylphosphate 7 7
16 Polyethylene 1.5 1.5
17 Tridecylphosphite 0.5 0.5
18 Zinc sulfate 0.15 0.15
19 Zinc oxide 0.15 0.15
Pigment 11.5 11.5
21
22 The compositions were tested according to ASTM pro-
23 cedures. Test specimen geo~etries were identical to those
24 described in Examples 1-4. The test results were as follows:
27
8CH-2143
~osml
1 TABLE 3
~; Properties g 10
~ 5
s; 6 Heat Deflect~on (F) 203 207
7 Izod Impact
8 (ft.lbs./in.n.) 3.8 4.8
Gardner Impact
9 (in.lbs.) 180 160
Tensile Elongation
ll (%) 67 39
Tensile Yield
12 (psi x 1o-2) 67 87
13 Tensile Break
14 (psi x 10-2) 67 71
Flexural Yield
(psi x 10-2) 91.7 122.2
16 Flexural ~Iodulus
(psi x 10-3) 353 381
l8
19 It is shown in Examples 9-10 that a radial tele-
block copolymer is effectiva in improving the Izod impact
21 stren~th of a polypllenyIene ether resin-high molecular weight
22 homopolystyrene composition. Improvements in tensile strength
23 and flexural properties are also obtained.
24
~bviously, other modifications and variations of
26 the present invention are possible in the li~ht of the above
27 teachings. It is ~lerefore, to be understood that changes
may be made in the particular em~odiments described above wl;ic'l ¦
I
8CH-2143
11 l08m~.
11 are with the full intended sco,oe of the invention as defined
8 ~ he ~ ded cla_,
.
I7
24
26
