U.S. patent application number 09/965274 was filed with the patent office on 2002-10-31 for compatibilized blends of alkenyl aromatic polymers, alpha-olefin/vinyl or vinylidene aromatic and/or sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene interpolymers and styrenic block copolymers.
Invention is credited to Chang, Dane, Chaudhary, Bharat I., Cheung, Yunwa Wilson, Diehl, Charles F., Guest, Martin J., Uzee, Andre J..
Application Number | 20020161125 09/965274 |
Document ID | / |
Family ID | 26930001 |
Filed Date | 2002-10-31 |
United States Patent
Application |
20020161125 |
Kind Code |
A1 |
Chang, Dane ; et
al. |
October 31, 2002 |
Compatibilized blends of alkenyl aromatic polymers,
alpha-olefin/vinyl or vinylidene aromatic and/or sterically
hindered aliphatic or cycloaliphatic vinyl or vinylidene
interpolymers and styrenic block copolymers
Abstract
A blend composition (and fabricated articles therefrom)
comprising; (A) one or more alkenyl aromatic polymers; (B) one or
more substantially random interpolymers comprising (1) polymer
units derived from; (a) at least one vinyl or vinylidene aromatic
monomer, or (b) at least one hindered aliphatic or cycloaliphatic
vinyl or vinylidene monomer, or (c) a combination of at least one
aromatic vinyl or vinylidene monomer and at least one hindered
aliphatic or cycloaliphatic vinyl or vinylidene monomer, and (2)
polymer units derived from at least one of ethylene and/or a
C.sub.3-20.alpha.-olefin; and (3) polymer units derived from one or
more of ethylenically unsaturated polymerizable monomers other than
those derived from (1) and (2); and, (C) one or more
compatibilizers; and wherein said blend has; a) a tensile strength
greater than 1500 psi; b) a pull force test (1/8" diameter) greater
than 15 lb; c) a Shore A Hardness greater than 79; d) a cycle time
in injection molding of less than 30 sec.
Inventors: |
Chang, Dane; (Sugarland,
TX) ; Cheung, Yunwa Wilson; (Lake Jackson, TX)
; Diehl, Charles F.; (Lake Jackson, TX) ; Guest,
Martin J.; (Lake Jackson, TX) ; Chaudhary, Bharat
I.; (Pearland, TX) ; Uzee, Andre J.; (Baton
Rouge, LA) |
Correspondence
Address: |
THE DOW CHEMICAL COMPANY
INTELLECTUAL PROPERTY SECTION
2301 N BRAZOSPORT BLVD
FREEPORT
TX
77541-3257
US
|
Family ID: |
26930001 |
Appl. No.: |
09/965274 |
Filed: |
September 27, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60236670 |
Sep 29, 2000 |
|
|
|
60266272 |
Feb 2, 2001 |
|
|
|
Current U.S.
Class: |
525/191 ;
525/232; 525/240; 525/241 |
Current CPC
Class: |
C08L 25/08 20130101;
C08L 53/02 20130101; C08L 25/08 20130101; C08L 2205/02 20130101;
C08L 2666/02 20130101; C08L 2666/02 20130101; C08L 25/06 20130101;
C08L 25/06 20130101; C08L 2666/06 20130101; C08L 23/0838 20130101;
C08L 23/0838 20130101 |
Class at
Publication: |
525/191 ;
525/232; 525/240; 525/241 |
International
Class: |
C08L 009/00; C08L
023/00; C08L 023/04; C08L 025/02 |
Claims
What is claimed is:
1. A blend composition comprising; (A) one or more alkenyl aromatic
polymers; (B) one or more substantially random interpolymers
comprising (1) from about 0.5 to about 15 mol percent of polymer
units derived from; (a) at least one vinyl or vinylidene aromatic
monomer, or (b) at least one hindered aliphatic or cycloaliphatic
vinyl or vinylidene monomer, or (c) a combination of at least one
aromatic vinyl or vinylidene monomer and at least one hindered
aliphatic or cycloaliphatic vinyl or vinylidene monomer, and (2)
from about 85 to about 99.5 mol percent polymer units derived from
at least one of ethylene and/or a C.sub.3-20 .alpha.- olefin; and
(3) from 0 to about 20 mol percent of polymer units derived from
one or more of ethylenically unsaturated polymerizable monomers
other than those derived from (1) and (2); and, (C) one or more
compatibilizers; and wherein said blend has; a) a tensile strength
greater than 1500 psi; b) a pull force test (1/8" diameter) greater
than 15 lb; c) a Shore A Hardness greater than 79; d) a cycle time
in injection molding of less than 30 sec.
2. The blend composition of claim 1 wherein; A) Component A is
present in an amount of from about 20 to about 70 percent by weight
(based on the combined weights of Components A, B and C; B)
Component B is present in an amount of from about 20 to about 70
percent by weight (based on the combined weights of Components A, B
and C; C) Component C is present in an amount of from about 1 to
about 30 percent by weight (based on the combined weights of
Components A, B and C) and wherein said blend has; a) a tensile
strength greater than 1700 psi; b) a pull force test (1/8"
diameter) greater than 17 lb; c) a Shore A Hardness greater than
82; and d) a cycle time in injection molding of less than 28
sec.
3. The blend composition of claim 1 wherein; A) Component A is
selected from the group consisting of GPPS (general purpose
polystyrene) and HIPS (high impact polystyrene); B) Component B is
selected from the group consisting of substantially random
ethylene/styrene and ethylene/propylene/styrene interpolymers; and;
C) Component C is selected from the group consisting of SBS
(styrene-butadiene-styrene) or SIS (styrene-isoprene-styrene) or
SEBS (styrene-ethylene-butylene-styrene) or SEPS
(styrene-ethylene-propylene-styrene) block copolymers or a
substantially random interpolymer other than that of Component B;
and wherein said blend has; a) a tensile strength greater than 1900
psi; b) a pull force test (1/8" diameter) greater than 21 lb; c) a
Shore A Hardness greater than 84; and d) a cycle time in injection
molding of less than 26 sec.
4. The blend of claim 3 wherein said pull force test is greater
than 40 lb.
5. An injection molded article having a paintability score of 5
(according to ASTM Method D-3359), prepared from a blend
composition comprising; (A) one or more alkenyl aromatic polymers;
(B) one or more substantially random interpolymers comprising (1)
from about 0.5 to about 15 mol percent of polymer units derived
from; (a) at least one vinyl or vinylidene aromatic monomer, or (b)
at least one hindered aliphatic or cycloaliphatic vinyl or
vinylidene monomer, or (c) a combination of at least one aromatic
vinyl or vinylidene monomer and at least one hindered aliphatic or
cycloaliphatic vinyl or vinylidene monomer, and (2)) from about 85
to about 99.5 mol percent of polymer units derived from at least
one of ethylene and/or a C.sub.3-20 .alpha.-olefin; and (3)) from 0
to about 20 mol percent of polymer units derived from one or more
of ethylenically unsaturated polymerizable monomers other than
those derived from (1) and (2); and, (C) one or more
compatibilizers; and wherein said blend has; a) a tensile strength
greater than 1500 psi; b) a pull force test (1/8" diameter) greater
than 15 lb; c) a Shore A Hardness greater than 79; d) a cycle times
in injection molding of less than 30 sec.
6. The injection molded article of claim 5 wherein; A) said
Component A is present in an amount of from about 20 to about 70
percent by weight (based on the combined weights of Components A, B
and C; B) said Component B is present in an amount of from about 20
to about 70 percent by weight (based on the combined weights of
Components A, B and C; and C) said Component C is present in an
amount of from about 1 to about 30 percent by weight (based on the
combined weights of Components A, B and C) and wherein said blend
has; a) a tensile strength greater than 1700 psi; b) a pull force
test (1/8" diameter) greater than 17 lb; c) a Shore A Hardness
greater than 82; and d) a cycle time in injection molding of less
than 28 sec.
7. The injection molded article of claim 5 wherein A) said
Component A is selected from the group consisting of GPPS (general
purpose polystyrene) and HIPS (high impact polystyrene); B) said
Component B is selected from the group consisting of substantially
random ethylene/styrene and ethylene/propylene/styrene
interpolymers; and; C) said Component C is selected from the group
consisting of SBS (styrene-butadiene-styrene) or SIS
(styrene-isoprene-styrene) or SEBS
(styrene-ethylene-butylene-styrene- ) or SEPS
(styrene-ethylene-propylene-styrene) block copolymers or a
substantially random interpolymer other than that of Component B;
and wherein said blend has; a) a tensile strength greater than 1900
psi; b) a pull force test (1/8" diameter) greater than 21 lb; c) a
Shore A Hardness greater than 84; and d) a cycle time in injection
molding of less than 26 sec.
8. The injection molded article of claim 7 wherein said pull force
test is greater than 40 lb.
9. The injection molded article of claim 5 in the form of a toy,
sports article, food container, household article, footware,
automotive article, or an assembly adhesive.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Application claims priority from U.S. Provisional
Application No. 60/236,670 filed on Sep. 29, 2000, in the name of
Dane Chang et al., and U.S. Provisional Application No. 60/266,272
filed on Feb. 2, 2001 also in the name of Dane Chang et al., the
entire contents of both of which are herein incorporated by
reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
FIELD OF THE INVENTION
[0003] This invention relates to thermoplastic blends comprising
one or more alkenyl aromatic polymers (Component A), one or more
substantially random interpolymers (Component B) and one or more
compatibilizers (Component C). Examples of such blends include
blends of ethylene styrene interpolymers (ESI) and/or ethylene
propylene styrene (EPS) interpolymers with polystyrene (PS) and/or
high impact polystyrene (HIPS) compatibilzed with SBS
(styrene-butadiene-styrene) or SIS (styrene-isoprene-styrene) or
SEBS (styrene-ethylene-butylene-styrene) or SEPS
(styrene-ethylene-propyl- ene-styrene) block copolymers.
[0004] This technology enables the production of novel materials
with a balance of flexibility, degree of hardness, modulus, short
cycle times (injection molding), tensile strength, pull force
strength and paintability.
BRIEF SUMMARY OF THE INVENTION
[0005] A blend composition (and fabricated articles therefrom)
comprising;
[0006] (A) one or more alkenyl aromatic polymers;
[0007] (B) one or more substantially random interpolymers
comprising
[0008] (1) polymer units derived from;
[0009] (a) at least one vinyl or vinylidene aromatic monomer,
or
[0010] (b) at least one hindered aliphatic or cycloaliphatic vinyl
or vinylidene monomer, or
[0011] (c) a combination of at least one aromatic vinyl or
vinylidene monomer and at least one hindered aliphatic or
cycloaliphatic vinyl or vinylidene monomer, and
[0012] (2) polymer units derived from at least one of ethylene
and/or a C.sub.3-20 .alpha.-olefin; and
[0013] (3) polymer units derived from one or more of ethylenically
unsaturated polymerizable monomers other than those derived from
(1) and (2); and,
[0014] (C) one or more compatibilizers;
[0015] and wherein said blend has;
[0016] a) a tensile strength greater than 1500 psi;
[0017] b) a pull force test (1/8" diameter) greater than 15 lb;
[0018] c) a Shore A Hardness greater than 79;
[0019] d) a cycle times in injection molding less than 30 sec.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Definitions
[0021] All references herein to elements or metals belonging to a
certain Group refer to the Periodic Table of the Elements published
and copyrighted by CRC Press, Inc., 1989. Also any reference to the
Group or Groups shall be to the Group or Groups as reflected in
this Periodic Table of the Elements using the IUPAC system for
numbering groups.
[0022] Any numerical values recited herein include all values from
the lower value to the upper value in increments of one unit
provided that there is a separation of at least 2 units between any
lower value and any higher value. As an example, if it is stated
that the amount of a component or a value of a process variable
such as, for example, temperature, pressure, time and the like is,
for example, from 1 to 90, preferably from 20 to 80, more
preferably from 30 to 70, it is intended that values such as 15 to
85, 22 to 68, 43 to 51, 30 to 32 etc. are expressly enumerated in
this specification. For values which are less than one, one unit is
considered to be 0.0001, 0.001, 0.01 or 0.1 as appropriate. These
are only examples of what is specifically intended and all possible
combinations of numerical values between the lowest value and the
highest value enumerated are to be considered to be expressly
stated in this application in a similar manner.
[0023] The term "hydrocarbyl" as employed herein means any
aliphatic, cycloaliphatic, aromatic, aryl substituted aliphatic,
aryl substituted cycloaliphatic, aliphatic substituted aromatic, or
aliphatic substituted cycloaliphatic groups.
[0024] The term "hydrocarbyloxy" means a hydrocarbyl group having
an oxygen linkage between it and the carbon atom to which it is
attached.
[0025] The term "interpolymer" is used herein to indicate a polymer
wherein at least two different monomers are polymerized to make the
interpolymer. This includes copolymers, terpolymers, etc.
[0026] The term "block copolymer" is used herein to mean elastomers
having at least one block segment of a hard polymer unit and at
least one block segment of a rubber monomer unit. However, the term
is not intended to include thermoelastic ethylene interpolymers
which are, in general, random polymers. Preferred block copolymers
contain hard segments of styrenic-type polymers in combination with
saturated or unsaturated rubber monomer segments. The structure of
the block copolymers useful in the present invention is not
critical and can be of the linear or radial type, either diblock or
triblock, or any combination of thereof.
[0027] Component A
[0028] For purposes of this invention, Component A is an alkenyl
aromatic polymer which is a melt-processable polymer or melt
processable impact-modified polymer in the form of polymerized
vinyl aromatic monomers as represented by the structure:
H.sub.2C.dbd.CRAr
[0029] wherein R is hydrogen or an alkyl radical that preferably
has no more than three carbon atoms and Ar is an aromatic group. R
is preferably hydrogen or methyl, most preferably hydrogen.
Aromatic groups Ar include phenyl and naphthyl groups. The aromatic
group Ar may be substituted. Halogen (such as Cl, F, Br), alkyl
(especially C.sub.1-C.sub.4 alkyl such as methyl, ethyl, propyl and
t-butyl), C.sub.1-C.sub.4 haloalkyl (such as chloromethyl or
chloroethyl) and alkoxyl (such as methoxyl or ethoxyl) substituents
are all useful. Styrene, para-vinyl toluene, .alpha.-methyl
styrene, 4-methoxy styrene, t-butyl styrene, chlorostyrene, vinyl
naphthalene and the like are all useful vinyl aromatic monomers.
Styrene is especially preferred.
[0030] The alkenyl aromatic polymer may be a homopolymer of a vinyl
aromatic monomer as described above. Polystyrene homopolymers are
the most preferred alkenyl aromatic polymers. Interpolymers of two
or more vinyl aromatic monomers are also useful.
[0031] Although not critical, the alkenyl aromatic polymer may have
a high degree of syndiotactic configuration; i.e., the aromatic
groups are located alternately at opposite directions relative to
the main chain that consists of carbon-carbon bonds. Homopolymers
of vinyl aromatic polymers that have syndiotacticity of 75% r diad
or greater or even 90% r diad or greater as measured by .sup.13C
NMR are useful herein.
[0032] The alkenyl aromatic polymer may also contain repeating
units derived from one or more other monomers that are
copolymerizable with the vinyl aromatic monomer. Suitable such
monomers include N-phenyl maleimide; acrylamide; ethylenically
unsaturated nitriles such as acrylonitrile and methacrylonitrile;
ethylenically unsaturated carboxylic acids and anhydrides such as
acrylic acid, methacrylic acid, fumaric anhydride and maleic
anhydride; esters of ethylenically unsaturated acids such as
C.sub.1-C.sub.8 alkyl acrylates and methacrylates, for example
n-butyl acrylate and methyl methacrylate; and conjugated dienes
such as butadiene or isoprene. The interpolymers of these types may
be random, block or graft interpolymers. Blends of interpolymers of
this type with homopolymers of a vinyl aromatic monomer can be
used. For example, styrene/C.sub.4-C.sub.8 alkyl acrylate
interpolymers and styrene-butadiene interpolymers are particularly
suitable as impact modifiers when blended into polystyrene. Such
impact-modified polystyrenes are useful herein.
[0033] In addition, the alkenyl aromatic polymers include those
modified with rubbers to improve their impact properties. The
modification can be, for example, through blending, grafting or
polymerization of a vinyl aromatic monomer (optionally with other
monomers) in the presence of a rubber compound. Examples of such
rubbers are homopolymers of C.sub.4-C.sub.6 conjugated dienes such
as butadiene or isoprene; ethylene/propylene interpolymers;
interpolymers of ethylene, propylene and a nonconjugated diene such
as 1,6-hexadiene or ethylidene norbornene; C.sub.4-C.sub.6 alkyl
acrylate homopolymers or interpolymers, including interpolymers
thereof with a C.sub.1-C.sub.4 alkyl acrylate. The rubbers are
conveniently prepared by anionic solution polymerization techniques
or by free radical initiated solution, mass or suspension
polymerization processes. Rubber polymers that are prepared by
emulsion polymerization may be agglomerated to produce larger
particles having a multimodal particle size distribution.
[0034] Preferred impact modified alkenyl aromatic polymers are
prepared by dissolving the rubber into the vinyl aromatic monomer
and any comonomers and polymerizing the resulting solution,
preferably while agitating the solution so as to prepare a
dispersed, grafted, impact modified polymer having rubber domains
containing occlusions of the matrix polymer dispersed throughout
the resulting polymerized mass. In such products, polymerized vinyl
aromatic monomer forms a continuous polymeric matrix. Additional
quantities of rubber polymer may be blended into the impact
modified polymer if desired.
[0035] Commercial PS (polystyrene), General purpose polystyrene
(GPPS), HIPS (high impact polystyrene), ABS
(acrylonitrile-butadiene-styrene) and SAN (styrene-acrylonitrile)
resins that are melt processable are particularly useful in this
invention.
[0036] Component B
[0037] The term "substantially random" (in the substantially random
interpolymer comprising polymer units derived from ethylene and one
or more .alpha.-olefin monomers with one or more vinyl or
vinylidene aromatic monomers and/or aliphatic or cycloaliphatic
vinyl or vinylidene monomers) as used herein means that the
distribution of the monomers of said interpolymer can be described
by the Bernoulli statistical model or by a first or second order
Markovian statistical model, as described by J. C. Randall in
POLYMER SEQUENCE DETERMINATION, Carbon-13 NMR Method, Academic
Press New York, 1977, pp. 71-78. Preferably substantially random
interpolymers do not contain more than 15 percent of the total
amount of vinyl aromatic monomer in blocks of vinyl aromatic
monomer of more than 3 units. More preferably, the interpolymer is
not characterized by a high degree of either isotacticity or
syndiotacticity. This means that in the carbon.sup.-13 NMR spectrum
of the substantially random interpolymer the peak areas
corresponding to the main chain methylene and methine carbons
representing either meso diad sequences or racemic diad sequences
should not exceed 75 percent of the total peak area of the main
chain methylene and methine carbons.
[0038] The interpolymers used to prepare the injection molded
articles of the present invention include the substantially random
interpolymers prepared by polymerizing i) ethylene and/or one or
more .alpha.-olefin monomers and ii) one or more vinyl or
vinylidene aromatic monomers and/or one or more sterically hindered
aliphatic or cycloaliphatic vinyl or vinylidene monomers, and
optionally iii) other polymerizable ethylenically unsaturated
monomer(s). Suitable .alpha.-olefins include for example,
.alpha.-olefins containing from 3 to about 20, preferably from 3 to
about 12, more preferably from 3 to about 8 carbon atoms.
Particularly suitable are ethylene, propylene,
butene-1,4-methyl-1-penten- e, hexene-1 or octene-1 or ethylene in
combination with one or more of propylene, butene-1,
4-methyl-1-pentene, hexene-1 or octene-1. These .alpha.-olefins do
not contain an aromatic moiety.
[0039] Other optional polymerizable ethylenically unsaturated
monomer(s) include norbornene and C.sub.1-10 alkyl or C.sub.6-10
aryl substituted norbornenes, with an exemplary interpolymer being
ethylene/styrene/norbor- nene.
[0040] Suitable vinyl or vinylidene aromatic monomers which can be
employed to prepare the interpolymers include, for example, those
represented by the following formula: 1
[0041] wherein R.sup.1 is selected from the group of radicals
consisting of hydrogen and alkyl radicals containing from 1 to
about 4 carbon atoms, preferably hydrogen or methyl; each R.sup.2
is independently selected from the group of radicals consisting of
hydrogen and alkyl radicals containing from 1 to about 4 carbon
atoms, preferably hydrogen or methyl; Ar is a phenyl group or a
phenyl group substituted with from 1 to 5 substituents selected
from the group consisting of halo, C.sub.1-4-alkyl, and
C.sub.1-4-haloalkyl; and n has a value from zero to about 4,
preferably from zero to 2, most preferably zero. Exemplary vinyl
aromatic monomers include styrene, vinyl toluene,
.alpha.-methylstyrene, t-butyl styrene, chlorostyrene, including
all isomers of these compounds, and the like. Particularly suitable
such monomers include styrene and lower alkyl- or
halogen-substituted derivatives thereof. Preferred monomers include
styrene, .alpha.-methyl styrene, the lower alkyl-(C.sub.1-C.sub.4)
or phenyl-ring substituted derivatives of styrene, such as for
example, ortho-, meta-, and para-methylstyrene, the ring
halogenated styrenes, para-vinyl toluene or mixtures thereof, and
the like. A more preferred aromatic vinyl monomer is styrene.
[0042] By the term "sterically hindered aliphatic or cycloaliphatic
vinyl or vinylidene compounds", it is meant addition polymerizable
vinyl or vinylidene monomers corresponding to the formula: 2
[0043] wherein A.sup.1 is a sterically bulky, aliphatic or
cycloaliphatic substituent of up to 20 carbons, R.sup.1 is selected
from the group of radicals consisting of hydrogen and alkyl
radicals containing from 1 to about 4 carbon atoms, preferably
hydrogen or methyl; each R.sup.2 is independently selected from the
group of radicals consisting of hydrogen and alkyl radicals
containing from 1 to about 4 carbon atoms, preferably hydrogen or
methyl; or alternatively R.sup.1 and A.sup.1 together form a ring
system. Preferred aliphatic or cycloaliphatic vinyl or vinylidene
compounds are monomers in which one of the carbon atoms bearing
ethylenic unsaturation is tertiary or quaternary substituted.
Examples of such substituents include cyclic aliphatic groups such
as cyclohexyl, cyclohexenyl, cyclooctenyl, or ring alkyl or aryl
substituted derivatives thereof, tert-butyl, norbornyl, and the
like. Most preferred aliphatic or cycloaliphatic vinyl or
vinylidene compounds are the various isomeric vinyl-ring
substituted derivatives of cyclohexene and substituted
cyclohexenes, and 5-ethylidene-2-norbornene. Especially suitable
are 1-, 3-, and 4-vinylcyclohexene. Simple linear non-branched
.alpha.-olefins including for example, .alpha.-olefins containing
from 3 to about 20 carbon atoms such as propylene, butene-1,
4-methyl-1-pentene, hexene-1 or octene-1 are not examples of
sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene
compounds.
[0044] One method of preparation of the substantially random
interpolymers includes polymerizing a mixture of polymerizable
monomers in the presence of one or more metallocene or constrained
geometry catalysts in combination with various cocatalysts, as
described in EP-A-0,416,815 by James C. Stevens et al. and U.S.
Pat. No. 5,703,187 by Francis J. Timmers, both of which are
incorporated herein by reference in their entirety. Preferred
operating conditions for such polymerization reactions are
pressures from atmospheric up to 3000 atmospheres and temperatures
from -30.degree. C. to 200.degree. C. Polymerizations and unreacted
monomer removal at temperatures above the autopolymerization
temperature of the respective monomers may result in formation of
some amounts of homopolymer polymerization products resulting from
free radical polymerization.
[0045] Examples of suitable catalysts, co catalysts, and methods
for preparing the substantially random interpolymers are disclosed
in U.S. application Ser. No. 702,475, filed May 20, 1991
(EP-A-514,828); as well as U.S. Pat. Nos. 5,055,438; 5,057,475;
5,096,867; 5,064,802; 5,132,380; 5,189,192; 5,321,106; 5,347,024;
5,350,723; 5,374,696; 5,399,635; 5,470,993; 5,703,187; 5,721,185,
5,919,983 and 6,150,297, all of which patents and applications are
incorporated herein by reference.
[0046] The substantially random .alpha.-olefin/vinyl aromatic
interpolymers can also be prepared by the methods described in JP
07/278230 employing compounds shown by the general formula 3
[0047] where Cp.sup.1 and Cp.sup.2 are cyclopentadienyl groups,
indenyl groups, fluorenyl groups, or substituents of these,
independently of each other; R.sup.1 and R.sup.2 are hydrogen
atoms, halogen atoms, hydrocarbon groups with carbon numbers of
1-12, alkoxyl groups, or aryloxyl groups, independently of each
other; M is a group IV metal, preferably Zr or Hf, most preferably
Zr; and R.sup.3 is an alkylene group or silanediyl group used to
cross-link Cp.sup.1 and Cp.sup.2).
[0048] The substantially random .alpha.-olefin/vinyl aromatic
interpolymers can also be prepared by the methods described by John
G. Bradfute et al. (W. R. Grace & Co.) in WO 95/32095; by R. B.
Pannell (Exxon Chemical Patents, Inc.) in WO 94/00500; and in
Plastics Technology, p. 25 (September 1992), all of which are
incorporated herein by reference in their entirety.
[0049] Also suitable are the substantially random interpolymers
which comprise at least one .alpha.-olefin/vinyl aromatic/vinyl
aromatic/.alpha.-olefin tetrad disclosed in U.S. application Ser.
No. 08/708,869 filed Sep. 4, 1996 and WO 98/09999 both by Francis
J. Timmers et al. These interpolymers contain additional signals in
their carbon-13 NMR spectra with intensities greater than three
times the peak to peak noise. These signals appear in the chemical
shift range 43.70-44.25 ppm and 38.0-38.5 ppm. Specifically, major
peaks are observed at 44.1, 43.9, and 38.2 ppm. A proton test NMR
experiment indicates that the signals in the chemical shift region
43.70-44.25 ppm are methine carbons and the signals in the region
38.0-38.5 ppm are methylene carbons.
[0050] Further preparative methods for the interpolymers used in
the present invention have been described in the literature. Longo
and Grassi (Makromol. Chem., Volume 191, pages 2387 to 2396 [1990])
and D'Anniello et al. (Journal of Applied Polymer Science, Volume
58, pages 1701-1706 [1995]) reported the use of a catalytic system
based on methylalumoxane (MAO) and cyclopentadienyltitanium
trichloride (CpTiCl.sub.3) to prepare an ethylene-styrene
copolymer. Xu and Lin (Polymer Preprints, Am. Chem. Soc., Div.
Polym. Chem.) Volume 35, pages 686,687 [1994]) have reported
copolymerization using a
MgCl.sub.2/TiCl.sub.4/NdCl.sub.3/Al(iBu).sub.3 catalyst to give
random copolymers of styrene and propylene. Lu et al (Journal of
Applied Polymer Science, Volume 53, pages 1453 to 1460 [1994]) have
described the copolymerization of ethylene and styrene using a
TiCl.sub.4/NdCl.sub.3/MgCl.sub.2/Al(Et).sub.3 catalyst. Sernetz and
Mulhaupt, (Macromol. Chem. Phys., v. 197, pp. 1071-1083, 1997) have
described the influence of polymerization conditions on the
copolymerization of styrene with ethylene using
Me.sub.2Si(Me.sub.4Cp)(N-- tert-butyl)TiCl.sub.2/methylaluminoxane
Ziegler-Natta catalysts. Copolymers of ethylene and styrene
produced by bridged metallocene catalysts have been described by
Arai, Toshiaki and Suzuki (Polymer Preprints, Am. Chem. Soc., Div.
Polym. Chem.) Volume 38, pages 349, 350 [1997]) and in U.S. pat.
No. 5,652,315, issued to Mitsui Toatsu Chemicals, Inc. The
manufacture of .alpha.-olefin/vinyl aromatic monomer interpolymers
such as propylene/styrene and butene/styrene are described in U.S.
Pat. No. 5,244,996, issued to Mitsui Petrochemical Industries Ltd
or U.S. pat. No. 5,652,315 also issued to Mitsui Petrochemical
Industries Ltd or as disclosed in DE 197 11 339 A1 to Denki Kagaku
Kogyo KK. All the above methods disclosed for preparing the
interpolymer component are incorporated herein by reference. The
random copolymers of ethylene and styrene as disclosed in Polymer
Preprints Vol 39, No. 1, March 1998 by Toru Aria et al. can also be
employed as blend components for the injection molded articles of
the present invention.
[0051] While preparing the substantially random interpolymer, an
amount of atactic vinyl aromatic homopolymer may be formed due to
homopolymerization of the vinyl aromatic monomer at elevated
temperatures. The presence of vinyl aromatic homopolymer is in
general not detrimental for the purposes of the present invention
and can be tolerated. The vinyl aromatic homopolymer may be
separated from the interpolymer, if desired, by extraction
techniques such as selective precipitation from solution with a non
solvent for either the interpolymer or the vinyl aromatic
homopolymer. For the purpose of the present invention it is
preferred that no more than 30 weight percent, preferably less than
20 weight percent based on the total weight of the interpolymers of
atactic vinyl aromatic homopolymer is present.
[0052] Component C (Compatibilizer)
[0053] Suitable unsaturated block copolymers include those
represented by the following formulas:
A--B--R(--B--A).sub.n Formula I
[0054] or
A.sub.x--(BA--).sub.y--BA Formula II
[0055] wherein each A is a polymer block comprising a vinyl
aromatic monomer, preferably styrene, and each B is a polymer block
comprising a conjugated diene, preferably isoprene or butadiene,
and optionally a vinyl aromatic monomer, preferably styrene; R is
the remnant of a multifunctional coupling agent; n is an integer
from 1 to 5; x is zero or 1; and y is a real number from zero to
4.
[0056] The preparation of the block copolymers useful herein is not
the subject of the present invention. Methods for the preparation
of such block copolymers are known in the art. Suitable catalysts
for the preparation of useful block copolymers with unsaturated
rubber monomer units include lithium based catalysts and especially
lithium-alkyls. U.S. Pat. No. 3,595,942 describes suitable methods
for hydrogenation of block copolymers with unsaturated rubber
monomer units to from block copolymers with saturated rubber
monomer units. The structure of the polymers is determined by their
methods of polymerization. For example, linear polymers result by
sequential introduction of the desired rubber monomer into the
reaction vessel when using such initiators as lithium-alkyls or
dilithiostilbene and the like, or by coupling a two segment block
copolymer with a difunctional coupling agent. Branched structures,
on the other hand, may be obtained by the use of suitable coupling
agents having a functionality with respect to the block copolymers
with unsaturated rubber monomer units of three or more. Coupling
may be effected with multifunctional coupling agents such as
dihaloalkanes or alkenes and divinyl benzene as well as with
certain polar compounds such as silicon halides, siloxanes or
esters of monohydric alcohols with carboxylic acids. The presence
of any coupling residues in the polymer may be ignored for an
adequate description of the block copolymers forming a part of the
composition of this invention.
[0057] Suitable block copolymers having unsaturated rubber monomer
units includes, but is not limited to, styrene-butadiene (SB),
styrene-isoprene(SI), styrene-butadiene-styrene (SBS),
styrene-isoprene-styrene (SIS),
.alpha.-methylstyrene-butadiene-.alpha.-m- ethylstyrene and
.alpha.-methylstyrene-isoprene-.alpha.-methylstyrene.
[0058] The styrenic portion of the block copolymer is preferably a
polymer or interpolymer of styrene and its analogs and homologs
including .alpha.-methylstyrene and ring-substituted styrenes,
particularly ring-methylated styrenes. The preferred styrenics are
styrene and .alpha.-methylstyrene, and styrene is particularly
preferred.
[0059] Block copolymers with unsaturated rubber monomer units may
comprise homopolymers of butadiene or isoprene or they may comprise
copolymers of one or both of these two dienes with a minor amount
of styrenic monomer.
[0060] Preferred block copolymers with saturated rubber monomer
units comprise at least one segment of a styrenic unit and at least
one segment of an ethylene-butene or ethylene-propylene copolymer.
Preferred examples of such block copolymers with saturated rubber
monomer units include styrene/ethylene-butene copolymers,
styrene/ethylene-propylene copolymers,
styrene/ethylene-butene/styrene (SEBS) copolymers,
styrene/ethylene-propylene/styrene (SEPS) copolymers.
[0061] Hydrogenation of block copolymers with unsaturated rubber
monomer units is preferably effected by use of a catalyst
comprising the reaction products of an aluminum alkyl compound with
nickel or cobalt carboxylates or alkoxides under such conditions as
to substantially completely hydrogenate at least 80 percent of the
aliphatic double bonds while hydrogenating no more than 25 percent
of the styrenic aromatic double bonds. Preferred block copolymers
are those where at least 99 percent of the aliphatic double bonds
are hydrogenated while less than 5 percent of the aromatic double
bonds are hydrogenated.
[0062] The proportion of the styrenic blocks is generally between 8
and 65 percent by weight of the total weight of the block
copolymer. Preferably, the block copolymers contain from 10 to 35
weight percent of styrenic block segments and from 90 to 65 weight
percent of rubber monomer block segments, based on the total weight
of the block copolymer.
[0063] The average molecular weights of the individual blocks may
vary within certain limits. In most instances, the styrenic block
segments will have number average molecular weights in the range of
5,000 to 125,000, preferably from 7,000 to 60,000 while the rubber
monomer block segments will have average molecular weights in the
range of 10,000 to 300,000, preferably from 30,000 to 150,000. The
total average molecular weight of the block copolymer is typically
in the range of 25,000 to 250,000, preferably from 35,000 to
200,000.
[0064] Further, the various block copolymers suitable for use in
the present invention may be modified by graft incorporation of
minor amounts of functional groups, such as, for example, maleic
anhydride by any of the methods well known in the art.
[0065] Block copolymers useful in the present invention are
commercially available, such as, for example, supplied by Shell
Chemical Company under the designation of KRATON.TM. and supplied
by Dexco Polymers under the designation of VECTOR.TM..
[0066] Also suitable as compatibilizers are high styrene content
substantially ramdom interpolymers having
[0067] Additives such as antioxidants (e.g., hindered phenolics
(e.g., Irganox.RTM. 1010), phosphites (e.g., Irgafos.RTM. 168)),
cling additives (e.g., PIB), antiblock additives, colourants,
pigments, fillers, and the like can also be included in the present
compositions, to the extent that they do not interfere with the
enhanced properties discovered by Applicants.
[0068] The compositions of the present invention are compounded by
any convenient method, including dry blending the individual
components and subsequently melt mixing, either directly in the
extruder or mill used to make the finished article (e.g., the
automotive part), or by pre-melt mixing in a separate extruder or
mill (e.g., a Banbury mixer).
[0069] There are many types of molding operations which can be used
to form useful fabricated articles or parts from the present
compositions, including various injection molding processes (e.g.,
that described in Modem Plastics Encyclopedia/89, Mid October 1988
Issue, Volume 65, Number 11, pp. 264-268, "Introduction to
Injection Molding" and on pp. 270-271, "Injection Molding
Thermoplastics", the disclosures of which are incorporated herein
by reference) and blow molding processes (e.g., that described in
Modern Plastics Encyclopedia/89, Mid October 1988 Issue, Volume 65,
Number 11, pp. 217-218,"Extrusion-Blow Molding", the disclosure of
which is incorporated herein by reference) and profile
extrusion.
[0070] Some of the fabricated articles include toys, sports
articles, containers such as for food or other household articles,
footware, automotive articles, such as soft facia, sealants and
assembly adhesives.
[0071] Properties of the Interpolymers and Blend Compositions of
the Present Invention
[0072] The blends comprise:
[0073] 1) greater than about 20, preferably of from about 20 to
about 70, most preferably of from about 25 to about 55 weight %,
(based on the combined weights of substantially random
interpolymer, the alkenyl aromatic homopolymers or copolymer and
the compatibilizer) of one or more alkenyl aromatic polymers
(Component A);
[0074] 2) of from about 20 to about 70, preferably of from about 25
to about 65, most preferably of from about 30 to about 60 weight %
(based on the combined weights of substantially random
interpolymer, the alkenyl aromatic homopolymers or copolymer and
the compatibilizer) of one or more substantially random
interpolymers (Component B); and
[0075] 3) of from about 1 to about 30, preferably of from about 5
to about 25, most preferably of from about 10 to about 20 weight %
(based on the combined weights of substantially random
interpolymer, the alkenyl aromatic homopolymers or copolymer and
the compatibilizer) of one or more compatibilizers (Component
C).
[0076] The molecular weight (Mw) of the alkenyl aromatic
homopolymers or copolymers used to prepare the blends of the
present invention is from about 100,000 to about 500,000,
preferably from about 120,000 to about 350,000, more preferably
130,000 to 325,000.
[0077] The alkenyl aromatic polymer material used to prepare the
blends of the present invention comprises greater than 50 and
preferably greater than 70 weight percent alkenyl aromatic
monomeric units. More preferably, the alkenyl aromatic polymer
material is comprised entirely of alkenyl aromatic monomeric units.
Most preferably the alkenyl aromatic polymer material is General
Purpose Polystyrene (GPPS) or High Impact Polystyrene (HIPS).
[0078] Component B comprises substantially random interpolymers of
.alpha.-olefin monomers, vinyl aromatic monomers and, optionally,
additional comonomers including ethylene/styrene copolymers and
terpolymers with .alpha.-olefins (especially propylene). The
substantially random interpolymers contain from about 0.5 to 15,
preferably from about 3 to about 10, more preferably from about 5
to about 8 mole percent of at least one vinyl or vinylidene
aromatic monomer and/or aliphatic or cycloaliphatic vinyl or
vinylidene monomer and from about 85 to about 99.5, preferably from
about 90 to about 97, more preferably from about 92 to about 95
mole percent of ethylene and/or at least one aliphatic
.alpha.-olefin having from 3 to about 20 carbon atoms.
[0079] Component C comprises styrene block copolymers with greater
than 20, preferably 25-60 and most preferably 30-50 weight percent
styrene; and/or substantially random interpolymers with 10-39,
preferably 15-33, most preferably 17-31 mole percent vinyl aromatic
monomer, with the proviso that the substantially random
interpolymer compatibilizer is other than that used as Component
B.
[0080] The blends of this invention may be processed by any known
fabrication techniques (including, but not limited to, injection
molding, compression molding, extrusion, calendering, thermoforming
and foaming) to produce articles of suitable morphology that
exhibit the following properties:
[0081] Tensile strength greater than 1500, preferably >1700,
most preferably >1900 psi
[0082] Pull force test (1/8" diameter): >15, preferably >17,
more preferably >21, even more preferably >30, most
preferably >40 lb
[0083] Shore A Hardness greater than 79, preferably >82 and most
preferably >84
[0084] Cycle times in injection molding: <30, preferably <28,
most preferably <26 sec
[0085] Paintable score of 5 according to ASTM Method D-3359.
[0086] The melt index (I.sub.2) of the substantially random
interpolymers used to prepare the blends of the present invention
is from about 0.01 to about 1000, preferably of from about 0.3 to
about 30, more preferably of from about 0.5 to about 10 g/10
min.
[0087] The molecular weight distribution (M.sub.w/M.sub.n) of the
substantially random interpolymer used to prepare the blends of the
present invention is from about 1.5 to about 20, preferably of from
about 1.8 to about 10, more preferably of from about 2 to about
5.
[0088] In addition, minor amounts of alkenyl aromatic homopolymers
or copolymers having a molecular weight of about 2,000 to about
50,000, preferably from about 4,000 to about 25,000 can be added in
an amount not exceeding about 20 wt % (based on the combined
weights of substantially random interpolymer and the various
alkenyl aromatic homopolymers or copolymers).
[0089] The following examples are illustrative of the invention,
but are not to be construed as to limiting the scope thereof in any
manner.
EXAMPLES
[0090] Test Methods
[0091] a) Melt Flow Measurements
[0092] The molecular weight of the substantially random
interpolymers used in the present invention is conveniently
indicated using a melt index measurement according to ASTM D-1238,
Condition 190.degree. C./2.16 kg (formally known as "Condition (E)"
and also known as I.sub.2) was determined. Melt index is inversely
proportional to the molecular weight of the polymer. Thus, the
higher the molecular weight, the lower the melt index, although the
relationship is not linear.
[0093] b) Styrene Analyses
[0094] Interpolymer styrene content and atactic polystyrene
concentration can be determined using proton nuclear magnetic
resonance (.sup.1H NMR) or by .sup.13C nuclear magnetic
resonance.
[0095] All proton NMR samples were prepared in
1,1,2,2-tetrachloroethane-d- .sub.2 (TCE-d.sub.2). The resulting
solutions were 1.6-3.2 percent polymer by weight. Melt index
(I.sub.2) was used as a guide for determining sample concentration.
Thus when the I.sub.2 was greater than 2 g/10 min, 40 mg of
interpolymer was used; with an I.sub.2 between 1.5 and 2 g/10 min,
30 mg of interpolymer was used; and when the I.sub.2 was less than
1.5 g/10 min, 20 mg of interpolymer was used. The interpolymers
were weighed directly into 5 mm sample tubes. A 0.75 mL aliquot of
TCE-d.sub.2 was added by syringe and the tube was capped with a
tight-fitting polyethylene cap. The samples were heated in a water
bath at 85.degree. C. to soften the interpolymer. To provide
mixing, the capped samples were occasionally brought to reflux
using a heat gun.
[0096] Proton NMR spectra were accumulated on a Varian VXR 300 with
the sample probe at 80.degree. C., and referenced to the residual
protons of TCE-d.sub.2 at 5.99 ppm. The delay times were varied
between 1 second, and data was collected in triplicate on each
sample. The following instrumental conditions were used for
analysis of the interpolymer samples:
[0097] Varian VXR-300, standard .sup.1H:
[0098] Sweep Width, 5000 Hz
[0099] Acquisition Time, 3.002 sec
[0100] Pulse Width, 8 .mu.sec
[0101] Frequency, 300 MHz
[0102] Delay, 1 sec
[0103] Transients, 16
[0104] The total analysis time per sample was about 10 minutes.
[0105] Initially, a .sup.1H NMR spectrum for a sample of the
polystyrene, STYRON.TM. 680 (available from the Dow Chemical
Company, Midland, Mich.) was acquired with a delay time of one
second. The protons were "labeled": b, branch; a, alpha; o, ortho;
m, meta; p, para, as shown in FIG. 1. 4
[0106] Integrals were measured around the protons labeled in FIG.
1; the `A` designates aPS. Integral A.sub.7.1(aromatic, around 7.1
ppm) is believed to be the three ortho/para protons; and integral
A.sub.6.6 (aromatic, around 6.6 ppm) the two meta protons. The two
aliphatic protons labeled .alpha. resonate at 1.5 ppm; and the
single proton labeled b is at 1.9 ppm. The aliphatic region was
integrated from about 0.8 to 2.5 ppm and is referred to as
A.sub.al. The theoretical ratio for A.sub.7.1: A.sub.6.6: A.sub.al
is 3:2:3, or 1.5:1:1.5, and correlated very well with the observed
ratios for the Styron.TM. 680 sample for several delay times of 1
second. The ratio calculations used to check the integration and
verify peak assignments were performed by dividing the appropriate
integral by the integral A.sub.6.6 Ratio A.sub.r is
A.sub.7.1/A.sub.6.6.
[0107] Region A.sub.6.6 was assigned the value of 1. Ratio Al is
integral A.sub.al/A.sub.6.6. All spectra collected have the
expected 1.5:1:1.5 integration ratio of (o+p):m:(.alpha.+b). The
ratio of aromatic to aliphatic protons is 5 to 3. An aliphatic
ratio of 2 to 1 is predicted based on the protons labeled .alpha.
and b respectively in FIG. 1. This ratio was also observed when the
two aliphatic peaks were integrated separately.
[0108] For the ethylene/styrene interpolymers, the .sup.1H NMR
spectra using a delay time of one second, had integrals C.sub.7.1,
C.sub.6.6, and C.sub.al defined, such that the integration of the
peak at 7.1 ppm included all the aromatic protons of the copolymer
as well as the o & p protons of aPS. Likewise, integration of
the aliphatic region C.sub.al in the spectrum of the interpolymers
included aliphatic protons from both the aPS and the interpolymer
with no clear baseline resolved signal from either polymer. The
integral of the peak at 6.6 ppm C.sub.6.6 is resolved from the
other aromatic signals and it is believed to be due solely to the
aPS homopolymer (probably the meta protons). (The peak assignment
for atactic polystyrene at 6.6 ppm (integral A.sub.6.6) was made
based upon comparison to the authentic sample STYRON.TM. 680.) This
is a reasonable assumption since, at very low levels of atactic
polystyrene, only a very weak signal is observed here. Therefore,
the phenyl protons of the copolymer must not contribute to this
signal. With this assumption, integral A.sub.6.6 becomes the basis
for quantitatively determining the aPS content.
[0109] The following equations were then used to determine the
degree of styrene incorporation in the ethylene/styrene
interpolymer samples:
(C Phenyl)=C.sub.7.1+A.sub.7.1-(1.5.times.A.sub.6.6)
(C Aliphatic)=C.sub.al-(15.times.A.sub.6.6)
s.sub.c=(C Phenyl)/5
e.sub.c=(C Aliphatic-(3.times.s.sub.c))/4
E=e.sub.c/(e.sub.c+s.sub.c)
S.sub.c=s.sub.c/(e.sub.c+s.sub.c)
[0110] and the following equations were used to calculate the mol %
ethylene and styrene in the interpolymers. 1 W t % E = E * 28 ( E *
28 ) + ( S c * 104 ) ( 100 ) and W t % S = S c * 104 ( E * 28 ) + (
S c * 104 ) ( 100 )
[0111] where: s.sub.c and e.sub.c are styrene and ethylene proton
fractions in the interpolymer, respectively, and S.sub.c and E are
mole fractions of styrene monomer and ethylene monomer in the
interpolymer, respectively.
[0112] The weight percent of aPS in the interpolymers was then
determined by the following equation: 2 Wt % a P S = ( W t % S ) *
( A 6.6 2 S c ) 100 + [ ( W t % S ) * ( A 6.6 2 S c ) ] * 100
[0113] The total styrene content was also determined by
quantitative Fourier Transform Infrared spectroscopy (FTIR).
[0114] Preparation of Ethylene/Styrene Interpolymers Used in
Examples and Comparative Experiments of Present Invention
[0115] ESI 1 and EPS-1 are substantially random interpolymers
prepared using the following polymerization procedure.
[0116] ESI 1 and EPS 1 were prepared in a continuously operating
loop reactor. An Ingersoll-Dresser twin screw pump provided the
mixing. The reactor ran liquid full at 475 psig (3,275 kPa). Raw
materials and catalyst/cocatalyst flows were fed into the reactor
through injectors and Kenics static mixers in the loop reactor
piping. From the discharge of the loop pump, the process flow goes
through two shell and tube heat exchangers before returning to the
suction of the loop pump. Upon exiting the last exchanger, loop
flow returned through the injectors and static mixers to the
suction of the pump. A second monomer/feed injector and mixer was
used if available. Heat transfer oil or tempered water was
circulated through the exchangers' jacket to control the loop
temperature. The exit stream of the loop reactor was taken off
between the two exchangers. The flow and solution density of the
exit stream was measured by a Micro-Motion.TM. mass flow meter.
[0117] Solvent was injected to the reactor primarily as part of the
feed flow to keep the ethylene in solution. A split stream from the
pressurization pumps prior to ethylene injection was taken to
provide a flush flow for the loop reactor pump seals. Additional
solvent is added as a diluent for the catalyst. Feed solvent was
mixed with uninhibited styrene monomer on the suction side of the
pressurization pump. The pressurization pump supplied solvent and
styrene to the reactor at approximately 650 psig (4,583 kPa). Fresh
styrene flow was measured by a Micro-Motion.TM. mass flow meter,
and total solvent/styrene flow was measured by a separate
Micro-Motion.TM. mass flow meter. Ethylene was supplied to the
reactor at approximately 690 psig (4,865 kPa). The ethylene stream
was measured by a Micro-Motion.TM. mass flow meter. A flow meter
/controller was used to deliver hydrogen into the ethylene stream
at the outlet of the ethylene control valve.
[0118] The ethylene/hydrogen mixture is at ambient temperature when
it is combined with the solvent/styrene stream. The temperature of
the entire feed stream as it entered the reactor loop was lowered
to approximately 2.degree. C. by a glycol cooled exchanger.
Preparation of the three catalyst components took place in three
separate tanks. Fresh solvent and concentrated
catalyst/cocatalyst/secondary co-catalyst premix were added and
mixed into their respective run tanks and fed into the reactor via
a variable speed Pulsafeeder.TM. diaphragm pumps. As previously
explained, the three component catalyst system entered the reactor
loop through an injector and static mixer into the suction side of
the twin screw pump. The raw material feed stream was also fed into
the reactor loop through an injector and static mixer upstream of
the catalyst injection point or through a feed injector/mixer
between the two exchangers, if available.
[0119] Polymerization was stopped with the addition of catalyst
kill (water) into the reactor product line after the
Micro-Motion.TM. mass flow meter measuring the solution density. A
static mixer in the line provided dispersion of the catalyst kill
and additives in the reactor effluent stream. This stream next
entered post reactor heaters that provided additional energy for
the solvent removal flash. This flash occurred as the effluent
exited the post reactor heater and the pressure was dropped from
475 psig (3,275 kPa) down to approximately 450 mmHg (60 kPa) of
absolute pressure at the reactor pressure control valve.
[0120] This flashed polymer entered the devolatilization section of
the process. The volatiles flashing from the devolatilization were
condensed with a glycol jacketed exchanger, passed through vacuum
pump, and were discharged to vapor/liquid separation vessel. In the
first stage vacuum system, solvent/styrene were removed from the
bottom of this vessel as recycle solvent while unreacted ethylene
exhausted from the top. The ethylene stream was measured with a
Micro-Motion.TM. mass flow meter. The measurement of vented
ethylene plus a calculation of the dissolved gases in the
solvent/styrene stream were used to calculate the ethylene
conversion. The polymer and remaining solvent was pumped with a
gear pump to a final devolatilizer. The pressure in the second
devolatilizer was operated at approximately 10 mmHg (1.4 kPa)
absolute pressure to flash the remaining solvent. The dry polymer
(<1000 ppm total volatiles) was pumped with a gear pump to an
underwater pelletizer with spin-dried, and collected. The
preparation conditions for each sample are summarized in Table
1.
1TABLE 1 Preparation Conditions for ESI 1 and EPS 1 Reactor Solvent
Ethylene Propylene Hydrogen Styrene Ethylene ESI Temp Flow Flow
Flow Flow Flow Conversion B/Ti MMAO.sup.e/Ti Co- # .degree. C.
lb/hr lb/hr lb/hr lb/hr lb/hr % Ratio Ratio Catalyst Catalyst ESI 1
115 21000 3120 N/A 0.37 1480 94 5.4 8.2 A.sup.a C.sup.c NK02029
33A- EPS 1 130 725 100 6 0.009 46 89 1.2 10 B.sup.b D.sup.d 382600
0529- 1900 .sup.aCatalyst A is (1H-cyclopenta[1]phenanthrene-2-
-yl)dimethyl(t-butylamido)-silanetitanium 1,4-diphenylbutadiene)
prepared as described in Example 3 of U.S. Pat. No. 6,150,297,
incorporated herein by reference. .sup.bCatalyst B is
;(1H-cyclopenta[1]phenanthrene--
2-yl)dimethyl(t-butylamido)-silanetitanium dimethyl) prepared as
described in Example 2 of U.S. Pat. No. 6,150,297, incorporated
herein by reference. .sup.cCocatalyst C is
tris(pentafluorophenyl)borane, (CAS #001109-15-5) .sup.dCocatalyst
D is bis(hydrogenated-tallowa- lkyl)methylammonium
tetrakis(pentafluorophenyl)borate prepared as described in Example
2 of U.S. Pat. No. 5,919,983 incorporated herein by reference.
.sup.ea modified methylaluminoxane commercially available from Akzo
Nobel as MMAO-3A (CAS #146905-79-5)
[0121]
2TABLE 2 Blend Components Melt Flow Copolymer Copolymer Copolymer
Copolymer Rate styrene styrene ethylene propylene Designation
(dg/min) (wt %) (mol %) (wt %) (wt %) ESI-1 10* 30 10 70 --
SBS-VECTOR .TM. 8* 43 -- -- 43 6241 (SBS 1) SBS- 20* 43 -- -- --
SINGAPRENE .TM. (SBS 2) PS-STYRON .TM.* 8** >97 -- -- >97
666D (PS) STYRON .TM.470 3** -- -- -- (HIPS) EPS-1 10* 24 -- 71.4
4.6 *ASTM D1238 (190.degree. C./2 Kg), **ASTM D1238 (200.degree.
C./5 Kg) STYRON is a product and registered trademark of The Dow
Chemical Company. VECTOR is a product and registered trademark of
Dexco Polymers SINGAPRENE is a product and registered trademark of
Singapore Plastics
[0122] Blends of ethylene styrene interpolymers (ESI 1) or ethylene
propylene styrene interpolymers (EPS 1) and polystrene (PS or HIPS)
compatibilized with SBS block copolymer were injection molded.
[0123] Compounding: ESI, or EPS 1, SBS and PS or HIPS were first
dry blended at certain weight ratios the compounded using a typical
single screw (general purpose) extruder (2.5") equipped with a
under-water pelletizer under the following conditions:
[0124] Zone temperature 400.degree. F., Melt temperature
410.degree. F., Die temperature 400.degree. F., Adapter temperature
400.degree. F., Underwater cut water temperature: 70.degree. F.,
Output 250-300 pounds/hr, Residence Time 2 minutes
[0125] Injection Molding: A 150 tons DEMAG injection molding
machine was used. The typical molding conditions include:
[0126] Injection pressure: 1200-1500 psi, Injection time: 1-2
seconds, Hold pressure: 300-500 psi, Hold time: 2-5 seconds,
Cooling time: 3-10 seconds
[0127] Tensile Test: Tensile Bar made according to ASTM Method 638
was used for measurement of ultimate tensile strength, yield
tensile, % elongation.
[0128] Pull Force Test: The 1/8" I.D. arm from a popular injection
molded Disney character Mickey Mouse was used for pull force
evaluation. Mickey Mouse made from various developmental toy resins
as well as competitors were tested on a standard Pull Force Gauge
(Master Carr, 0-50 pounds at 1/2 pound increments).
[0129] Paint Stripping Test: Two types of paint (ESI and TPE
based--5 colors each) from Rainbow Forest, China are used. Toy
parts are first spray painted, cure overnight, marked with sharp
blade at 3 different locations (25 squares each), and then
subjected to stripping with a adhesive tape. The number of squares
stripped with the tape was used to determine how good the paint
adheres to the toy. A score of 5 means no square was stripped.
[0130] Cycle Time: The cycle time required to injection mold,
without distortion, a popular McDonald toy character HAMBURGLAR.TM.
was used to compare various developmental toy resins and to the
competitors. This mold was chosen due to its relatively thick body,
which requires longer cycle time.
3TABLE 3 Comparative Examples of ESI/HIPS blends (no SBS)* Tensile
Strength Arm pull force* Cycle time** Comp Ex Blend Composition
(psi) (lb) (sec) Paintability #1 100 wt % ESI 1632 20 >40 5 #2
90 wt % ESI/10 wt % HIPS 1507 17 >40 5 #3 80 wt % ESI/20 wt %
HIPS 1190 17 >40 5 #4 70 wt % ESI/30 wt % HIPS 1080 17 >40 5
#5 60 wt % ESI/40 wt % HIPS 1036 18 37-40 5 #6 50 wt % ESI/50 wt %
HIPS 1000 22 33-37 5 *Examples #1-#6, demonstrate the poor
compatibility between ESI and HIPS. As more HIPS were added (e.g.
from 0 to 50%) into the ESI 1, the lower the tensile strength of
the blends (e.g. from 1632 to 1000 psi).
[0131]
4TABLE 4 Comparative Examples of ESI/SBS blend (no PS)* Tensile
Strength Arm pull force* Cycle time** Comp Ex Blend Composition
(psi) (lb) (sec) Paintability #7 50 wt % ESI/50 wt % SBS1 2594 --
22 5 *Example #7 demonstrates the good compatibility between ESI
and SBS. As 50% SBS were added into ESI 1, the tensile strength
increased to 2594 psi.
[0132]
5TABLE 5 Comparative Examples of SBS/HIPS blend (no ESI)* Tensile
Strength Arm pull force* Cycle time** Comp Ex Blend Composition
(psi) (lb) (sec) Paintability #8 50 wt % SBS2/50 wt % HIPS 2603 --
37 4 Example #8 demonstrates the good compatibility between SBS and
HIPS. As 2603 psi tensile strength were achieved with a 50/50 SBS
and HIPS blend. The co-continuous phases observed from TEM
confirmed the good compatibilities between ESI & SBS, as well
as between SBS & HIPS.
[0133]
6TABLE 6 Comparative Examples of ESI/PS blends (no SBS)* Tensile
Strength Arm pull force* Cycle time** Comp Ex Blend Composition
(psi) (lb) (sec) Paintability #9 100 wt % ESI 1632 20 >40 5 #10
90 wt % ESI/10 wt % PS 1607 19 >40 5 #11 80 wt % ESI/20 wt % PS
1301 17 >40 5 #12 70 wt % ESI/30 wt % PS 1205 17 37-40 5 #13 60
wt % ESI/40 wt % PS 907 17 35-38 5 #14 50 wt % ESI/50 wt % PS 808
19 33-36 5 *These data demonstrate the poor compatibility between
ESI and PS. As 10-50% PS were added to ESI 1, the tensile strength
decreased from 1607 (#10) to 808 psi (#14).
[0134]
7TABLE 7 Examples of ESI/SBS/HIPS blends* Tensile Strength Arm pull
force* Cycle time** Ex Blend Composition (psi) (lb) (sec)
Paintability Comp Ex #15 50 wt % ESI/0 wt % SBS1/50 wt % HIPS 1000
22 32-35 5 #1 40 wt % ESI/10 wt % SBS1/50 wt % HIPS 2220 39 20-22 5
#2 35 wt % ESI/15 wt % SBS1/50 wt % HIPS 2300 38 17-18 5 #3 30 wt %
ESI/20 wt % SBS1/50 wt % HIPS 2363 44 17-18 5 Comp Ex #16 60 wt %
ESI/0 wt % SBS1/40 wt % HIPS 1036 18 22-25 5 #4 50 wt % ESI/10 wt %
SBS1/40 wt % HIPS 1641 28 22-25 5 #5 45 wt % ESI/15 wt % SBS1/40 wt
% HIPS 1922 33 17-18 5 #6 40 wt % ESI/20 wt % SBS1/40 wt % HIPS
1929 35 17-18 5 #7 35 wt % ESI/25 wt % SBS1/40 wt % HIPS 2060 38
17-18 5 *Examples 1-3 demonstrate the effectiveness of SBS as
compatibilizer between ESI and HIPS at 50 wt. % HIPS level. As 10%
SBS were added to a ESI/HIPS blend, the tensile strength more than
doubled from 1000 to 2220 psi. As the SBS concentrations continue
increased to 15% & 20%, the tensile strength increased to 2300
& 2363 psi, respectively. Examples #4-7 #demonstrate the
effectiveness of SBS as compatibilizer between ESI and HIPS at 40
wt % HIPS level. As seen, as the SBS increased from 10% to 25%, the
tensile strength increased from 1641 (#4) to 2060 psi (#7),
respectively.
[0135]
8TABLE 8 Examples of ESI/SBS/PS blends* Tensile Strength Arm pull
force* Cycle time** Ex Blend Composition (psi) (lb) (sec)
Paintability Comp Ex #17 50 wt % ESI/0 wt % SBS1/50 wt % PS 808 19
33-36 5 #8 45 wt % ESI/5 wt % SBS1/50 wt % PS 1789 33 22-25 5 #9 40
wt % ESI/10 wt % SBS1/50 wt % PS 2053 52 17-18 5 #10 37.5 wt %
ESI/12.5 wt % SBS1/50 wt % PS 2389 56 17-18 5 #11 30 wt % ESI/20 wt
% SBS1/50 wt % PS 2445 58 17-18 5 Comp Ex #18 60 wt % ESI/0 wt %
SBS1/40 wt % PS 907 17 35-38 5 #12 50 wt % ESI/10 wt % SBS1/40 wt %
PS 2022 42 17-18 5 #13 48 wt % ESI/12 wt % SBS1/40 wt % PS 2213 47
17-18 5 #14 45 wt % ESI/15 wt % SBS1/40 wt % PS 2261 48 17-18 5 #15
40 wt % ESI/20 wt % SBS1/40 wt % PS 2169 46 17-18 5 #16 35 wt %
ESI/25 wt % SBS1/40 wt % PS 2287 48 17-18 5 *Examples #8-#11
demonstrate the effectiveness of SBS as compatibilizer between ESI
and PS at 50 wt. % PS level. With only 5% SBS addition, the tensile
strength more than doubled from 808 (#17) to 1789 psi (#8). The
tensile strength continue increasing to # 2445 psi as the SBS
increased to 20% (#11). Examples #12-#16 demonstrate the
effectiveness of SBS as compatibilizer between ESI and PS at 40 wt.
% PS level. With 10% SBS addition, the tensile strength increased
from 907 (#18) to 2022 psi (#12). The # tensile strength continued
to increase to 2287 psi as 25% PS was added (#16). In regard to the
"Arm Pull Force Test", as the tensile strength increases, the arm
pull force also increases responsively in all cases shown above. In
terms of "Cycle Time", as seen in the examples above, when SBS was
used as compatiblizer, the cycle time of the blends were
significantly reduced.
[0136]
9TABLE 9 Example of EPS/SBS/PS blends Tensile Strength Arm pull
force* Cycle time** Ex Blend Composition (psi) (lb) (sec)
Paintability Comp Ex #19 100 wt % EPS 1432 18 >40 5 #17 40 wt %
EPS/10 wt % SPS1/50 wt % PS 2268 50 17-18 5 #18 48 wt % EPS/12 wt %
SPS1/40 wt % PS 1936 44 17-18 5
* * * * *