U.S. patent application number 10/209285 was filed with the patent office on 2003-09-25 for elastomeric articles prepared from controlled distribution block copolymers.
This patent application is currently assigned to Kraton Polymers U.S. LLC. Invention is credited to Clawson, Margaret Ann Burns, Eiden, Keith Edward, Groot, Hendrik De, Handlin,, Dale Lee JR., Willis, Carl Lesley.
Application Number | 20030181584 10/209285 |
Document ID | / |
Family ID | 27737076 |
Filed Date | 2003-09-25 |
United States Patent
Application |
20030181584 |
Kind Code |
A1 |
Handlin,, Dale Lee JR. ; et
al. |
September 25, 2003 |
Elastomeric articles prepared from controlled distribution block
copolymers
Abstract
The present invention relates to elastomeric articles prepared
from novel anionic block copolymers of mono alkenyl arenes and
conjugated dienes, and to blends of such block copolymers with
other polymers. The block copolymers are selectively hydrogenated
and have mono alkenyl arene end blocks and controlled distribution
blocks of mono alkenyl arenes and conjugated dienes. The block
copolymer may be blended with at least one other polymer selected
from the group consisting of olefin polymers, styrene polymers,
amorphous resins, and engineering thermoplastic resins.
Inventors: |
Handlin,, Dale Lee JR.;
(Houston, TX) ; Willis, Carl Lesley; (Houston,
TX) ; Clawson, Margaret Ann Burns; (Houston, TX)
; Groot, Hendrik De; (Amsterdam, NL) ; Eiden,
Keith Edward; (Houston, TX) |
Correspondence
Address: |
PAUL S MADAN
MADAN, MOSSMAN & SRIRAM, PC
2603 AUGUSTA, SUITE 700
HOUSTON
TX
77057-1130
US
|
Assignee: |
Kraton Polymers U.S. LLC
Houston
TX
|
Family ID: |
27737076 |
Appl. No.: |
10/209285 |
Filed: |
July 31, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60355210 |
Feb 7, 2002 |
|
|
|
Current U.S.
Class: |
525/88 |
Current CPC
Class: |
C08L 53/025 20130101;
C08L 2666/02 20130101; C08L 53/025 20130101; C08L 91/00 20130101;
C09J 153/025 20130101; C08L 53/02 20130101; C08L 53/02 20130101;
C08L 95/00 20130101; C08L 2666/24 20130101; C08L 2666/02 20130101;
C08L 2666/24 20130101; C08L 53/00 20130101; C08L 2666/02 20130101;
C08L 2666/02 20130101; C08L 2666/24 20130101; C08L 2666/24
20130101; C08L 2666/02 20130101; C08L 2666/04 20130101; C08L
2666/04 20130101; C08L 2666/24 20130101; C08L 2666/24 20130101;
C08L 2666/24 20130101; C08L 2666/04 20130101; C08L 2666/02
20130101; C08L 2666/04 20130101; C08L 53/00 20130101; C08L 2666/02
20130101; C08F 297/04 20130101; C08L 77/00 20130101; C08L 23/10
20130101; C08L 25/06 20130101; C08L 53/025 20130101; C09D 153/02
20130101; Y10T 428/13 20150115; C08L 53/02 20130101; C09D 153/02
20130101; C09J 153/02 20130101; C08L 53/025 20130101; C08L 101/00
20130101; C09J 153/02 20130101; C08L 23/12 20130101; C09J 153/02
20130101; C08L 95/00 20130101; C09J 153/025 20130101; C09D 153/02
20130101; C09J 153/025 20130101; Y10T 428/31931 20150401; C08F
287/00 20130101; C08L 101/00 20130101; C08L 77/00 20130101; C08L
53/02 20130101; C09D 153/025 20130101; C09D 153/025 20130101; C08L
23/10 20130101; C09D 153/025 20130101; Y10T 428/249921
20150401 |
Class at
Publication: |
525/88 |
International
Class: |
C08L 053/00 |
Claims
What is claimed is:
1. An elastomeric article comprising at least one hydrogenated
block copolymer and, optionally, at least one other polymer
selected from the group consisting of olefin polymers, styrene
polymers, tackifying resins and engineering thermoplastic resins,
wherein said hydrogenated block copolymer has the general
configuration: A-B, A-B-A, or (A-B).sub.nX, where n is an integer
from 2 to about 30, and X is coupling agent residue and wherein: a.
prior to hydrogenation each A block is a mono alkenyl arene
homopolymer block and each B block is a controlled distribution
copolymer block of at least one conjugated diene and at least one
mono alkenyl arene; b. subsequent to hydrogenation about 0-10% of
the arene double bonds have been reduced, and at least about 90% of
the conjugated diene double bonds have been reduced; c. each A
block having an average molecular weight between about 3,000 and
about 60,000 and each B block having an average molecular weight
between about 30,000 and about 300,000; d. each B block comprises
one or more terminal regions adjacent to the A blocks that are rich
in conjugated diene units and a region not adjacent to the A blocks
that is rich in mono alkenyl arene units; e. the total amount of
mono alkenyl arene in the hydrogenated block copolymer is about 15
percent weight to about 75 percent weight; and f. the weight ratio
of conjugated diene to mono alkenyl arene in the B block is between
about 5:1 and about 1:2.
2. The elastomeric article according to claim 1 wherein said mono
alkenyl arene is styrene and said conjugated diene is selected from
the group consisting of isoprene and butadiene.
3. The elastomeric article according to claim 2 wherein said
conjugated diene is butadiene, and wherein about 20 to about 80 mol
percent of the condensed butadiene units in block B have
1,2-configuration.
4. The elastomeric article according to claim 3 wherein in block B
there are fewer than 20 consecutive units of any one monomer
between that of each different monomer.
5. The elastomeric article according to claim 4 wherein the polymer
is an ABA polymer and each block B has a center region with a
minimum ratio of butadiene units to styrene units.
6. The elastomeric article according to claim 2 wherein the styrene
blockiness index of the block B is less than about 10 percent, said
styrene blockiness index being defined to be the proportion of
styrene units in the block B having two styrene neighbors on the
polymer chain.
7. The elastomeric article according to claim 1 wherein said
hydrogenated block copolymer is an (A-B).sub.nX block copolymer
where each A block has an average molecular weight of about 5,000
to about 20,000, each B block has an average molecular weight of
about 30,000 to about 100,000, and the total molecular weight is
about 80,000 to about 140,000.
8. The elastomeric article according to claim 7 comprising 100
parts by weight of said hydrogenated block copolymer and about 5 to
about 50 parts by weight of a polymer extending oil.
9. The elastomeric article according to claim 7 comprising 100
parts by weight of said hydrogenated block copolymer and about 5 to
about 50 parts by weight of an olefin polymer selected from the
group consisting of ethylene homopolymers, ethylene/alpha olefin
copolymers, propylene homopolymers, propylene/alpha olefin
copolymers, high impact polypropylene, and ethylene/vinyl acetate
copolymers.
10. The elastomeric article according to claim 9 also comprising
about 5 to about 50 parts by weight of a tackifying resin.
11. The elastomeric article according to claim 8 also comprising
about 5 to about 40 parts by weight of a styrene polymer selected
from the group consisting of crystalline polystyrene, high impact
polystyrene, syndiotactic polystyrene and
acrylonitrile/butadiene/styrene terpolymer.
12. The elastomeric article according to claim 7 comprising 100
parts by weight of said hydrogenated block copolymer and about 5 to
about 20 parts by weight of an ethylene/vinyl aromatic
interpolymer.
13. The elastomeric article according to claim 12 wherein said
ethylene/vinyl aromatic interpolymer is a substantially random
ethylene/styrene interpolymer.
14. The elastomeric article according to claim 1 wherein said
hydrogenated block copolymer is an (A-B).sub.nX block copolymer
where each A block has an average molecular weight of about 10,000
to about 40,000, each B block has an average molecular weight of
about 60,000 to about 140,000, and the total molecular weight is
about 140,000 to about 220,000.
15. The elastomeric article according to claim 14 comprising 100
parts by weight of said hydrogenated block copolymer and about 10
to about 50 parts by weight of an olefin polymer selected from the
group consisting of ethylene homopolymers, ethylene/alpha olefin
copolymers, propylene homopolymers, propylene/alpha olefin
copolymers, high impact polypropylene, and ethylene/vinyl acetate
copolymers.
16. The elastomeric article according to claim 15 also comprising
about 20 to about 150 parts by weight of a polymer extending
oil.
17. The elastomeric article according to claim 14 comprising 100
parts by weight of said hydrogenated block copolymer and about 10
to about 80 parts by weight of at least one polymer selected from
the group consisting of poly(phenylene oxides), syndiotactic
polystyrene, cyclic olefin copolymers and
acrylonitrile/butadiene/styrene terpolymers.
18. A formulated elastomeric composition comprising at least one
hydrogenated block copolymer and at least one component selected
from the group consisting of fillers, reinforcements, polymer
extending oils and polyolefins, wherein said hydrogenated block
copolymer has the general configuration A-B, A-B-A, or
(A-B).sub.nX, where n is an integer from 2 to about 30, and X is
coupling agent residue and wherein: a. prior to hydrogenation each
A block is a mono alkenyl arene homopolymer block and each B block
is a controlled distribution copolymer block of at least one
conjugated diene and at least one mono alkenyl arene; b. subsequent
to hydrogenation about 0-10% of the arene double bonds have been
reduced, and at least about 90% of the conjugated diene double
bonds have been reduced; c. each A block having an average
molecular weight between about 3,000 and about 60,000 and each B
block having an average molecular weight between about 30,000 and
about 300,000; d. each B block comprises one or more terminal
regions adjacent to the A blocks that are rich in conjugated diene
units and a region not adjacent to the A blocks that is rich in
mono alkenyl arene units; e. the total amount of mono alkenyl arene
in the hydrogenated block copolymer is about 15 percent weight to
about 75 percent weight; and f. the weight ratio of conjugated
diene to mono alkenyl arene in the B block is between about 5:1 and
about 1:2.
19. A cap seal formed from the formulated elastomeric composition
of claim 18.
20. The cap seal of claim 19 wherein said formulated elastomeric
composition comprises 100 parts by weight of said hydrogenated
block copolymer and about 50 to about 125 parts by weight of a
process extender oil, to 50 parts by weight of polypropylene and
optionally 10 to 60 parts by weight silica.
21. The elastomeric article according to claim 1 wherein the
article is in the form of a film, sheet, coating, band, strip,
profile, molding, foam, tape, fabric, thread, filament, ribbon,
fiber, plurality of fibers or, fibrous web.
22. The elastomeric article according to claim 1 wherein said
article is formed in a process selected from the group consisting
of injection molding, over molding, dipping, extrusion, roto
molding, slush molding, fiber spinning, film making or foaming.
23. The elastomeric article according to claim 1 comprising about 5
to 20 percent weight of said hydrogenated block copolymer and about
80 to about 95 percent weight of an engineering thermoplastic
resin.
24. The elastomeric article according to claim 23 wherein said
engineering thermoplastic resin is selected from the group
consisting of thermoplastic polyester, thermoplastic polyurethane,
poly(arylether), poly(aryl sulfone), polycarbonate, acrylic resins,
acetal resin, polyamide, halogenated thermoplastic and nitrile
barrier resin.
25. The elastomeric article according to claim 1 wherein said
hydrogenated block copolymer is a functionalized block
copolymer.
26. The elastomeric article according to claim 25 wherein said
hydrogenated block copolymer has been grafted with an acid compound
or its derivative.
27. The elastomeric article according to claim 26 wherein said acid
compound or its derivative is selected from the group consisting of
maleic anhydride, maleic acid, fumaric acid, and its
derivatives.
28. The elastomeric article according to claim 26 wherein said acid
compound or its derivative is maleic anhydride or maleic acid.
29. The elastomeric article according to claim 28 containing 75 to
95 weight percent of an engineering thermoplastic selected from the
group consisting of polyamides and polyurethanes and 5 to 25 weight
percent of the functionalized block polymer.
30. The elastomeric article according to claim 1 comprising about 5
to 40 percent weight of said hydrogenated block copolymer and about
60 to about 95 percent weight of a polystyrene homopolymer or
copolymer.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority from copending,
commonly assigned U.S. patent application Serial No. 60/355,210,
filed Feb. 7, 2002, entitled Novel Block Copolymers and Method for
Making Same.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to elastomeric articles prepared from
novel anionic block copolymers of mono alkenyl arenes and
conjugated dienes, and to blends of such block copolymers with
other polymers. The invention also relates to formed articles and
methods for forming articles from such novel block copolymers.
[0004] 2. Background of the Art
[0005] The preparation of block copolymers of monoalkenyl arenes
and conjugated dienes is well known. One of the first patents on
linear ABA block copolymers made with styrene and butadiene is U.S.
Pat. No. 3,149,182. These polymers in turn could be hydrogenated to
form more stable block copolymers, such as those described in U.S.
Pat. No. 3,595,942 and Re. No. 27,145. Since then, a large number
of new styrene diene polymers have been developed. Now a novel
anionic block copolymer based on monoalkenyl arene end blocks and
controlled distribution mid blocks of mono alkenyl arenes and
conjugated dienes has been discovered and is described in
copending, commonly assigned U.S. patent application Serial No.
60/355,210, entitled "NOVEL BLOCK COPOLYMERS AND METHOD FOR MAKING
SAME". Methods for making such polymers are described in detail in
the above-mentioned patent application. What has now been found is
that blends or compounds of these novel block copolymers with
processing oils and other polymers have surprising property
advantages, and show promising utility in a variety of end-use
applications, including injection molding, extruded goods and
polymer modification.
SUMMARY OF THE INVENTION
[0006] In one aspect of the present invention we have discovered
that a novel composition comprising at least one hydrogenated block
copolymer having a controlled distribution block of a monoalkenyl
arene and conjugated diene, and optionally including another
polymer, has superior properties for many applications. We have
also discovered that these compositions can be used in various
forming processes, and that they also have a number of advantages
in processing.
[0007] Accordingly, the broad aspect of the present invention is an
elastomeric article comprising at least one hydrogenated block
copolymer and, optionally, at least one other polymer selected from
the group consisting of olefin polymers, styrene polymers,
tackifying resins and engineering thermoplastic resins, wherein
said hydrogenated block copolymer has the general configuration:
A-B, A-B-A, or (A-B).sub.nX; where n is an integer from 2 to about
30, and X is coupling agent residue and wherein (a.) prior to
hydrogenation each A block is a mono alkenyl arene homopolymer
block and each B block is a controlled distribution copolymer block
of at least one conjugated diene and at least one mono alkenyl
arene; (b.) subsequent to hydrogenation about 0-10% of the arene
double bonds have been reduced, and at least about 90% of the
conjugated diene double bonds have been reduced; (c.) each A block
having an average molecular weight between about 3,000 and about
60,000 and each B block having an average molecular weight between
about 30,000 and about 300,000; (d.) each B block comprises one or
more terminal regions adjacent to the A blocks that are rich in
conjugated diene units and a region not adjacent to the A blocks
that is rich in mono alkenyl arene units; (e.) the total amount of
mono alkenyl arene in the hydrogenated block copolymer is about 20
percent weight to about 80 percent weight; and (f.) the weight
ratio of conjugated diene to mono alkenyl arene in the B block is
between about 5:1 and about 1:2.
[0008] In another aspect of the present invention we have shown
that the elastomeric article can be formed in a wide variety of
processes, including injection molding, compression molding, over
molding, dipping, extrusion, roto molding, slush molding, fiber
spinning, blow molding, polymer modification, cast film making,
blown film making and foaming.
[0009] In still another aspect of the present invention, the
hydrogenated controlled distribution polymer of the present
invention may be functionalized in a variety of ways, including
reaction with maleic acid or anhydride. Such functionalized
polymers have additional polarity that makes them particularly
useful where adhesion to other polar polymers is important, such as
in over molding applications.
[0010] The elastomeric articles of the present invention have a
number of surprising properties. These properties include, for
example, the unusual stress-strain response, which shows that a
composition of the present invention exhibits a stiffer rubbery
response to strain, therefore requiring more stress to extend the
same length. This is an extremely useful property that allows the
use of less material to achieve the same force in a given product.
Elastic properties are also modified, exhibiting increasing modulus
with increasing elongation, and there is a reduced occurrence of
the rubbery plateau region where large increases in elongation are
required to procure an increase in stress. Another surprising
property is reduced coefficient of friction while retaining
elastomeric properties. This is important for applications where a
soft material is desired without a high friction surface. Still
another surprising property is increased tear strength.
[0011] The controlled distribution copolymers of the present
invention offer additional advantages in their ability to be easily
processed using equipment generally designed for processing
thermoplastic polystyrene, which is one of the most widely known
and used alkenyl arene polymers. Melt processing can be
accomplished via extrusion or injection molding using either single
screw or twin screw techniques that are common to the
thermoplastics industry. Solution or spin casting techniques can
also be used as appropriate. A particularly interesting application
is in over molding where a composition containing the controlled
distribution block copolymer and optionally other thermoplastic
polymers and process aides are injection molded onto a substrate of
a more rigid polymer to impart a softer feel or different
frictional characteristics. The polymers of the present invention
provide improved adhesion to polar polymers. Adhesion to very polar
materials such as polyamides or polyurethanes may be further
improved by functionalizing the polymer of the present invention,
for example with maleic anhydride.
[0012] In yet another aspect of the present invention, the
elastomeric article can be processed into the form of a film,
sheet, multi layer laminate, coating, band, strip, profile,
molding, foam, tape, fabric, thread, filament, ribbon, fiber,
plurality of fibers, or fibrous web. Another particularly
interesting application is thermoplastic films which retain the
processability of styrenic block copolymers but exhibit a higher
"elastic power" similar to spandex polyurethanes. As compounded
with polyethylene or with a combination of tackifying resin and
polyethylene, the controlled distribution copolymers of the present
invention can meet these performance expectations. The resultant
films show significant improvements in puncture resistance and
strength, and reduced viscosity, when compared with common
styrene/ethylene-butylene block copolymers. The same controlled
distribution styrene/butadiene (25/75 wt/wt) copolymer can also be
formulated in a film compound with oil and polystyrene, wherein it
exhibits higher strength and improved energy recovery and
transparency in comparison with a control formulation based on a
styrene/ethylene-butylene/styrene block copolymer. Molding
applications formulated using oil and polypropylene have a reduced
viscosity and coefficient of friction, and may be used in
applications such as cap seals. It should also be possible to
produce such cap seals without using undesirable slip agents.
[0013] Finally, the copolymers of the present invention can be
compounded with other components not adversely affecting the
copolymer properties. Exemplary materials that could be used as
additional components would include, without limitation, pigments,
antioxidants, stabilizers, surfactants, waxes, and flow promoters.
The polymers of the present invention are useful in a wide variety
of applications including, for example, molded and extruded goods
such as toys, grips, handles, shoe soles, tubing, sporting goods,
sealants, gaskets, and oil gels. The compositions also find use as
rubber toughening agents for polyolefins, polyvinyl chloride,
polystyrene, polyamide, polyurethane, polyester, polycarbonate and
epoxy resins. The polymers of the present invention are also useful
in alloys and blends, and as compatibilizers for a variety of
polymers and other materials. Improved elasticity when compared
with conventional styrenic block copolymers makes these copolymers
particularly useful for adhesives, including both
pressure-sensitive and hot-melt adhesives.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] The key component of the present invention is the novel
block copolymer containing monoalkenyl arene end blocks and a
unique midblock of a monoalkenyl arene and a conjugated diene.
Surprisingly, the combination of (1) a unique order for the monomer
addition and (2) the use of diethyl ether or other ethers as a
component of the solvent (which will be referred to as "randomizing
agents", in keeping with the common usage of the term) results in a
certain marked uniformity of the distribution of the two monomers
(herein termed a "controlled distribution" polymerization, i.e., a
polymerization resulting in a "controlled distribution" structure),
and also results in the presence of certain mono alkenyl arene rich
regions and certain conjugated diene rich regions in the polymer
block. For purposes hereof, "controlled distribution" is defined as
referring to a molecular structure lacking well-defined blocks of
either monomer, with "runs" of any given single monomer attaining a
preferred maximum number average of about 20 units, as shown by
either the presence of only a single Tg, intermediate between the
Tg's of either monomer alone, when analyzed using differential
scanning calorimetry ("DSC") (thermal) methods or via mechanical
methods, or as shown via proton nuclear magnetic resonance
("H-NMR") methods. This controlled distribution structure is very
important in maintaining the rubbery properties of the polymer with
a single, narrow Tg, because the controlled distribution structure
ensures that there is virtually no phase separation of the two
monomers, i.e., in contrast with block copolymers in which the
monomers actually remain as separate "microphases", with distinct
Tg's, but are actually chemically bonded together which produces
much more plastic physical properties. The presence of the arene
monomer in the rubber segment allows preferential interactions that
improve tensile and tear strength as well as adhesion to styrene
containing polymers. The controlled distribution structure assures
that only one Tg is present and that, therefore, the thermal
performance of the resulting copolymer is predictable and, in fact,
predeterminable. Furthermore, when a copolymer having such a
controlled distribution structure is then used as one block in a
di-block, tri-block or multi-block copolymer, it provides the
properties of a rubbery block with the adhesion characteristics of
a more polar block. Modification of certain other properties is
also achievable.
[0015] It is also an important aspect of the present invention that
the subject copolymer block also has three distinct
regions--conjugated diene rich regions on the end of the block and
adjacent to the A blocks and a mono alkenyl arene rich region not
adjacent to the A block and near the middle or center of the block.
What is desired is a mono alkenyl arene/conjugated diene controlled
distribution copolymer block, wherein the proportion of mono
alkenyl arene units increases gradually to a maximum near the
middle or center of the block and then decreases gradually until
the polymer block is fully polymerized. For sequentially prepared
block copolymers A-B-A, the B block will have terminal regions rich
in conjugated diene units, and a center region that is rich in mono
alkenyl arene units. When the block copolymer is prepared via a
coupling route, it will have a structure (A-B).sub.nX. In that case
each B block will have at least one region adjacent to the A block
that is rich in conjugated diene units. The other end not adjacent
to the A block may or may not be rich in conjugated diene units.
The remainder of the block will be therefore rich in mono alkenyl
arene units.
[0016] Another important aspect of the present invention is to
control the microstructure or vinyl content of the conjugated diene
in the controlled distribution copolymer block. The term "vinyl
content" refers to the fact that a conjugated diene is polymerized
via 1,2-addition (in the case of butadiene--it would be
3,4-addition in the case of isoprene). Although a pure "vinyl"
group is formed only in the case of 1,2-addition polymerization of
1,3-butadiene, the effects of 3,4-addition polymerization of
isoprene (and similar addition for other conjugated dienes) on the
final properties of the block copolymer will be similar. The term
"vinyl" refers to the presence of a pendant vinyl group on the
polymer chain. When referring to the use of butadiene as the
conjugated diene, it is preferred that about 20 to about 80 mol
percent of the condensed butadiene units in the copolymer block
have 1,2 vinyl configuration. Preferably about 30 to about 70 mol
percent of the condensed butadiene units should have 1,2
configuration. This is effectively controlled by varying the
relative amount of the randomization agent. As will be appreciated,
the randomization agent serves two purposes--it creates the
controlled distribution of the mono alkenyl arene and conjugated
diene, and also controls the microstructure of the conjugated
diene. Suitable ratios of randomization agent to lithium are
disclosed and taught in U.S. Pat. Re No. 27,145.
[0017] Regarding the monomers used in preparing the novel
controlled distribution copolymers of the present invention, the
alkenyl arene can be selected from styrene, alpha-methylstyrene,
para-methylstyrene, vinylnaphthalene, and para-butyl styrene,
including mixtures thereof. Of these, styrene is most preferred and
is commercially available, and relatively inexpensive, from a
variety of manufacturers. The conjugated dienes for use herein are
1,3-butadiene and substituted butadienes such as isoprene,
piperylene, 2,3-dimethyl-1,3-butadiene, and 1-phenyl-1,3-butadiene,
or mixtures thereof. Of these, 1,3-butadiene is most preferred.
[0018] As discussed above, the controlled distribution polymer
block has diene rich region(s) adjacent to the A block and an arene
rich region not adjacent to the A block, and typically near the
center of the block. Typically the region adjacent to the A block
comprises the first 15 to 25% of the block and comprises the diene
rich region(s), with the remainder considered to be arene rich. The
term "diene rich" means that the region has a measurably higher
ratio of diene to arene than the arene rich region. Another way to
express this is the proportion of mono alkenyl arene units
increases gradually along the polymer chain to a maximum near the
middle or center of the block (if we are describing an ABA
structure) and then decreases gradually until the polymer block is
fully polymerized. For the controlled distribution block the weight
ratio of conjugated diene to mono alkenyl arene is between about
5:1 and about 1:2, preferably between about 3:1 and about 1:1.
[0019] A particular feature of the present invention is that the
resultant copolymer is relatively uniform in its distribution of
the two monomers within a polymer chain, thus offering the
improvements in Tg and property modification suggested by the
identity of the starting monomers. A proton (hydrogen) nuclear
magnetic resonance (H-NMR) procedure may preferably be used to
assay for this advantageous controlled distribution, using
techniques known to those skilled in the art. Alternatively, a DSC
method may be used as an assay, determining the controlled
structure of the polymerization by confirming the presence of a
desired single Tg as is characteristic of a controlled distribution
copolymer.
[0020] The potential for blockiness can also be inferred from
measurement of the UV-visible absorbance in a wavelength range
suitable for the detection of polystyrillithium end groups during
the polymerization of the B block. A sharp and substantial increase
in this value is indicative of a substantial increase in
polystyrillithium chain ends. In this process, this will only occur
if the conjugated diene concentration drops below the critical
level to maintain controlled distribution polymerization. Any
styrene monomer that is present at this point will add in a blocky
fashion. The term "styrene blockiness" is defined to be the
proportion of S units in the polymer having two S nearest neighbors
on the polymer chain. Expressed thus,
Polymer-Bd-S-(S).sub.n-S-Bd-Polymer- , where n greater than zero is
defined to be blocky styrene. For example, if n equals 8 in the
example above, then the blockiness index would be 80%.
[0021] As used herein, "thermoplastic block copolymer" is defined
as a block copolymer having at least a first block of a mono
alkenyl arene, such as styrene and a second block of a controlled
distribution copolymer of diene and mono alkenyl arene. The method
to prepare this thermoplastic block copolymer is via any of the
methods generally known for block polymerizations. The present
invention includes as an embodiment a thermoplastic copolymer
composition, which may be either a di-block, tri-block copolymer or
multi-block composition. In the case of the di-block copolymer
composition, one block is the alkenyl arene-based homopolymer block
and polymerized therewith is a second block of a controlled
distribution copolymer of diene and alkenyl arene. In the case of
the tri-block composition, it comprises, as end-blocks the glassy
alkenyl arene-based homopolymer and as a mid-block the controlled
distribution copolymer of diene and alkenyl arene. Where a
tri-block copolymer composition is prepared, the controlled
distribution diene/alkenyl arene copolymer can be herein designated
as "B" and the alkenyl arene-based homopolymer designated as
"A".
[0022] The A-B-A, tri-block compositions can be made by either
sequential polymerization or coupling. In the sequential solution
polymerization technique, the mono alkenyl arene is first
introduced to produce the relatively hard aromatic block, followed
by introduction of the controlled distribution diene/alkenyl arene
mixture to form the mid block, and then followed by introduction of
the mono alkenyl arene to form the terminal block. In addition to
the linear, A-B-A configuration, the blocks can be structured to
form a radial (branched) polymer, (A-B).sub.nX, or both types of
structures can be combined in a mixture. Some A-B diblock polymer
can be present but preferably at least about 70 weight percent of
the block copolymer is A-B-A or radial (or otherwise branched so as
to have 2 or more terminal resinous blocks per molecule) so as to
impart strength.
[0023] It is also important to control the molecular weight of the
various blocks. For an AB diblock, desired block weights are 3,000
to about 60,000 for the mono alkenyl arene A block, and 30,000 to
about 300,000 for the controlled distribution conjugated diene/mono
alkenyl arene B block. Preferred ranges are 5000 to 45,000 for the
A block and 50,000 to about 250,000 for the B block. For the
triblock, which may be a sequential ABA or coupled (AB).sub.2X
block copolymer, the A blocks should be 3,000 to about 60,000,
preferably 5000 to about 45,000, while the B block for the
sequential block should be about 30,000 to about 300,000, and the B
blocks (two) for the coupled polymer half that amount. The total
average molecular weight for the triblock copolymer should be from
about 40,000 to about 400,000, and for the radial copolymer from
about 60,000 to about 600,000. These molecular weights are most
accurately determined by light scattering measurements.
[0024] An important feature of the thermoplastic elastomeric
di-block and tri-block polymers of the present invention, including
one or more controlled distribution diene/alkenyl arene copolymer
blocks and one or more mono alkenyl arene blocks, is that they have
at least two Tg's, the lower being the combined Tg of the
controlled distribution copolymer block which is an intermediate of
its constituent monomers' Tg's. Such Tg is preferably at least
about -60 degrees C., more preferably from about -40 degrees C. to
about zero degrees C., and most preferably from about -40 degrees
C. to about -10 degrees C. The second Tg, that of the mono alkenyl
arene "glassy" block, is preferably more than about 80 degrees C. ,
more preferably from about 80 degrees C. to about 105 degrees C.
The presence of the two Tg's, illustrative of the microphase
separation of the blocks, contributes to the notable elasticity and
strength of the material in a wide variety of applications, and its
ease of processing and desirable melt-flow characteristics.
[0025] The block copolymer is selectively hydrogenated.
Hydrogenation can be carried out via any of the several
hydrogenation or selective hydrogenation processes known in the
prior art. For example, such hydrogenation has been accomplished
using methods such as those taught in, for example, U.S. Pat. Nos.
3,494,942; 3,634,594; 3,670,054; 3,700,633; and Re. No. 27,145.
Hydrogenation can be carried out under such conditions that at
least about 90 percent of the conjugated diene double bonds have
been reduced, and between zero and 10 percent of the arene double
bonds have been reduced. Preferred ranges are at least about 95
percent of the conjugated diene double bonds reduced, and more
preferably about 98 percent of the conjugated diene double bonds
are reduced. Alternatively, it is possible to hydrogenate the
polymer such that aromatic unsaturation is also reduced beyond the
10 percent level mentioned above. In that case, the double bonds of
both the conjugated diene and arene may be reduced by 90 percent or
more.
[0026] In an alternative, the block copolymer of the present
invention may be functionalized in a number of ways. One way is by
treatment with an unsaturated monomer having one or more functional
groups or their derivatives, such as carboxylic acid groups and
their salts, anhydrides, esters, imide groups, amide groups, and
acid chlorides. The preferred monomers to be grafted onto the block
copolymers are maleic anhydride, maleic acid, fumaric acid, and
their derivatives. A further description of functionalizing such
block copolymers can be found in Gergen et al, U.S. Pat. No.
4,578,429 and in U.S. Pat. No. 5,506,299. In another manner the
selectively hydrogenated block copolymer of the present invention
may be functionalized by grafting silicon or boron containing
compounds to the polymer as taught in U.S. Pat. No. 4,882,384. In
still another manner, the block copolymer of the present invention
may be contacted with an alkoxy-silane compound to form
silane-modified block copolymer. In yet another manner, the block
copolymer of the present invention may be functionalized by
grafting at least one ethylene oxide molecule to the polymer as
taught in U.S. Pat. No. 4,898,914, or by reacting the polymer with
carbon dioxide as taught in U.S. pat. No. 4,970,265. Still further,
the block copolymers of the present invention may be metallated as
taught in U.S. Pat. Nos. 5,206,300 and 5,276,101, wherein the
polymer is contacted with an alkali metal alkyl, such as a lithium
alkyl. And still further, the block copolymers of the present
invention may be functionalized by grafting sulfonic groups to the
polymer as taught in U.S. Pat. No. 5,516,831.
[0027] One of the surprising compositions of the present invention
is the combination of the hydrogenated block copolymer and a
polymer extending oil. While in the absence of oil, these polymers
exhibit a stiffer elastomeric behavior than a traditional triblock
polymer, in the presence of oil, they exhibit a softer elastomeric
behavior. Especially preferred are the types of oil that are
compatible with the elastomeric segment of the block copolymer.
While oils of higher aromatics content are satisfactory, those
petroleum-based white oils having low volatility and less than 50%
aromatic content are preferred. The oils should additionally have
low volatility, preferable having an initial boiling point above
about 500.degree. F. The amount of oil employed varies from about 0
to about 300 parts by weight per hundred parts by weight rubber, or
block copolymer, preferably about 20 to about 150 parts by
weight.
[0028] The block copolymers of the present invention may be blended
with a large variety of other polymers, including olefin polymers,
styrene polymers, tackifying resins, and engineering thermoplastic
resins.
[0029] Olefin polymers include, for example, ethylene homopolymers,
ethylene/alpha-olefin copolymers, propylene homopolymers,
propylene/alpha-olefin copolymers, high impact polypropylene,
butylene homopolymers, butylene/alpha olefin copolymers, and other
alpha olefin copolymers or interpolymers. Representative
polyolefins include, for example, but are not limited to,
substantially linear ethylene polymers, homogeneously branched
linear ethylene polymers, heterogeneously branched linear ethylene
polymers, including linear low density polyethylene (LLDPE), ultra
or very low density polyethylene (ULDPE or VLDPE), medium density
polyethylene (MDPE), high density polyethylene (HDPE) and high
pressure low density polyethylene (LDPE). Other polymers included
hereunder are ethylene/acrylic acid (EEA) copolymers,
ethylene/methacrylic acid (EMAA) ionomers, ethylene/vinyl acetate
(EVA) copolymers, ethylene/vinyl alcohol (EVOH) copolymers,
ethylene/cyclic olefin copolymers, polypropylene homopolymers and
copolymers, propylene/styrene copolymers, ethylene/propylene
copolymers, polybutylene, ethylene carbon monoxide interpolymers
(for example, ethylene/carbon monoxide (ECO) copolymer,
ethylene/acrylic acid/carbon monoxide terpolymer and the like.
Still other polymers included hereunder are polyvinyl chloride
(PVC) and blends of PVC with other materials.
[0030] Styrene polymers include, for example, crystal polystyrene,
high impact polystyrene, medium impact polystyrene,
styrene/acrylonitrile copolymers, styrene/acrylonitrile/butadiene
(ABS) polymers, syndiotactic polystyrene and styrene/olefin
interpolymers. Representative styrene/olefin interpolymers are
substantially random ethylene/styrene interpolymers, preferably
containing at least 20, more preferably equal to or greater than 25
weight percent interpolymerized styrene monomer.
[0031] For the purposes of the specification and claims, the term
"engineering thermoplastic resin" encompasses the various polymers
found in the classes listed in Table A below, and further defined
in U.S. Pat. No. 4,107,131, the disclosure of which is hereby
incorporated by reference.
1 TABLE A 1. Thermoplastic Polyester 2. Thermoplastic Polyurethane
3. Poly(aryl ether) and Poly(aryl sulfone) 4. Polycarbonate 5.
Acetal resin 6. Polyamide 7. Halogenated thermoplastic 8. Nitrile
barrier resin 9. Poly(methyl methacrylate)
[0032] Tackifying resins include polystyrene block compatible
resins and midblock compatible resins. The polystyrene block
compatible resin may be selected from the group of coumarone-indene
resin, polyindene resin, poly(methyl indene) resin, polystyrene
resin, vinyltoluene-alphamethylsty- rene resin, alphamethylstyrene
resin and polyphenylene ether, in particular
poly(2,6-dimethyl-1,4-phenylene ether). Such resins are e.g. sold
under the trademarks "HERCURES", "ENDEX", "KRISTALEX", "NEVCHEM"
and "PICCOTEX". Resins compatible with the hydrogenated (mid) block
may be selected from the group consisting of compatible Cs
hydrocarbon resins, hydrogenated C.sub.5 hydrocarbon resins,
styrenated C.sub.5 resins, C.sub.5/C.sub.9 resins, styrenated
terpene resins, fully hydrogenated or partially hydrogenated Cg
hydrocarbon resins, rosins esters, rosins derivatives and mixtures
thereof. These resins are e.g. sold under the trademarks
"REGALITE", "REGALREZ", "ESCOREZ" and "ARKON". The resin employed
will typically have a viscosity at 350.degree. F., of no more than
300 centipoise.
[0033] The polymer blends of the present invention may be
compounded further with other polymers, oils, fillers,
reinforcements, antioxidants, stabilizers, fire retardants,
antiblocking agents, lubricants and other rubber and plastic
compounding ingredients without departing from the scope of this
invention.
[0034] Examples of various fillers that can be employed are found
in the 1971-1972 Modern Plastics Encyclopedia, pages 240-247. A
reinforcement may be defined simply as the material that is added
to a resinous matrix to improve the strength of the polymer. Most
of these reinforcing materials are inorganic or organic products of
high molecular weight. Various examples include glass fibers,
asbestos, boron fibers, carbon and graphite fibers, whiskers,
quartz and silica fibers, ceramic fibers, metal fibers, natural
organic fibers, and synthetic organic fibers. Especially preferred
are reinforced polymer blends of the instant invention containing
about 2 to about 80 percent by weight glass fibers, based on the
total weight of the resulting reinforced blend. Coupling agents,
such as various silanes, may be employed in the preparation of the
reinforced blends.
[0035] Regarding the relative amounts of the various ingredients,
this will depend in part upon the particular end use and on the
particular block copolymer that is selected for the particular end
use. Table B below shows some notional compositions expressed in
percent weight, which are included in the present invention:
2TABLE B Applications, Compositions and Ranges Application
Ingredients Composition % w. Films, Molding, Alloys Polymer 1-99%
Ethylene copolymers: 99-1% EVA, Ethylene/styrene Personal Hygiene
Films Polymer 0-75% and Fibers PE 0-30% PP 0-30% Tackifying Resin
5-30% End Block Resin 5-20% Personal Hygiene Films Polymer 50-90%
and Fibers PE 5-30% Tackifying Resin 0-40% Personal Hygiene Films
Polymer 45-85% and Fibers PS 10-25% Oil 5-30% Injection Molded
articles Polymer 25-85% Polyolefin 5-50% Oil 10-50% Injection
molded/extrusion Polymer 55-90% PPO 10-50% PS 10-50% Engineering
Plastic 10-50% Oil 0-50% Cap Seals Polymer 25-60% Oil 25-50% PP
10-30% Filler 0-25% Lubricant 0 to 3% Engineering Thermoplastic
Polymer or Maleated 5-30% toughening Polymer Engineering 70-95%
thermoplastic, e.g. Nylon 6,6, TPU Asphalt Modification Polymer
2-15% Asphalt 85-98% Dipped Goods Polymer 60-100% Plasticizer, oil
0-40% Polymer Modification Polymer 5-30% ABS, PS, HIPS 70-95%
[0036] The polymer of the present invention may be used in a large
number of applications, either as a neat polymer or in a compound.
The following various end uses and/or processes are meant to be
illustrative, and not limiting to the present invention:
[0037] Polymer modification applications
[0038] Injection molding of toys, medical devices
[0039] Extruding films, tubing, profiles
[0040] Over molding applications for personal care, grips, soft
touch applications, for automotive parts, such as airbags, steering
wheels, etc
[0041] Dipped goods, such as gloves
[0042] Thermoset applications, such as in sheet molding compounds
or bulk molding compounds for trays
[0043] Roto molding for toys and other articles
[0044] Slush molding of automotive skins
[0045] Thermal spraying for coatings
[0046] Blown film for medical devices
[0047] Blow molding for automotive/industrial parts
[0048] Asphalt modification
[0049] Films and fibers for personal hygiene applications
EXAMPLES
[0050] The following examples are provided to illustrate the
present invention. The examples are not intended to limit the scope
of the present invention and they should not be so interpreted.
Amounts are in weight parts or weight percentages unless otherwise
indicated.
Example 1
[0051] Various controlled distribution block copolymers of the
present invention were prepared according to the process disclosed
in copending patent application Serial No. 60/355,210 referenced
above. All polymers were selectively hydrogenated linear ABA block
copolymers where the A blocks were polystyrene blocks and the B
block prior to hydrogenation was a styrene butadiene controlled
distribution block having terminal regions that are rich in
butadiene units and a center region that was rich in styrene units.
The various polymers are shown in Table 1 below. These polymers
were then used in the various applications described in the other
Examples. Step I MW is the molecular weight of the first A block,
Step II MW is the molecular weight of the AB blocks and Step III MW
is the molecular weight of the ABA blocks. The polymers were
hydrogenated such that greater than about 95% of the diene double
bonds have been reduced.
3TABLE 1 Controlled Distribution Polymers % Sty- 1,2- Polymer Step
I Step II Step III rene in Styrene BD PSC Number MW(k) MW(k) MW(k)
Step II Blockiness (%) (%) 1 10.5 106.3 118.6 12.6 65.6 34.5 29.75
2 10.5 98.6 110.8 12.5 65 38 29.53 3 9.2 90.6 99.9 24.9 50 35.8
40.12 4 9.7 92.3 102.8 37.6 43 35.3 48.3 5 13.9 140.8 158.2 37.6 43
35 50.15 6 10.6 101.4 112.6 25.1 49 36.2 40 7 10.3 99.3 111.9 25.2
51 37.1 40.31 8 8.2 91.2 98.9 25.1 43.9 37 37 9 32 162 194.8 37.8
58 34.3 58.1 10 29.4 159.4 189.2 50 49 33.6 65.8 11 24 120.9 145.8
40 59 33.6 58.9 12 30.3 164.3 196.8 24 65 35.4 48.2 13 29.9 163.3
195.9 38 57 34.5 58.2 14 8.4 88.5 95.8 25 46 36.1 38.3 15 9 86.8
95.5 25 48 35.9 39.3 where "MW(k)" = molecular weight in thousands,
"Styrene Blockiness" = the blockiness of all of the styrene units
where "MW(k)" = molecular weight in thousands, "Styrene Blockiness"
= the blockiness of all of the styrene units polymer and "PSC(%)" =
wt % of styrene in the final polymer
Example 2
[0052] In this example three different block copolymers were
compounded with varying amounts of an ethylene vinyl acetate
copolymer (EVA) and the compounds were extruded into films. One of
the block copolymers was a selectively hydrogenated SBS block
copolymer (KRATON G 1652) and the other two block copolymers were
controlled distribution block copolymers #14 and #15. The relative
amounts and test results are shown in Table 2 below. As shown in
Table 2, adding 20% KRATON polymer to EVA increases impact
resistance, decreases hysteresis set and increases recoverable
energy in films. The improved impact resistance is important to
reduce failure of a film from an external force, such as dropping.
The increased recoverable energy and decreased hysteresis set is
desirable for improved elasticity of a film. The advantage of
polymers 14 and 15 over G11652 shows in the increased isotropic
behavior seen in the Elmendorf Tear data. Isotropic tear is
advantageous in film applications where straight tear along a seam
is necessary, such as food wrap or wrapping for sterile surgical
kits.
4TABLE 2 Compound Unit Direction EVA 2-1 2-2 2-3 2-4 2-5 Block
Copolymer Type # 14 # 15 G-1652 # 15 G-1652 Block Copolymer Amount
%/wt 0% 20% 20% 20% 80% 80% EVA Copolymer Amount %/wt 100% 80% 80%
80% 20% 20% Property Tensile Properties Tensile psi MD 4727 3855
3846 4072 3344 6392 TD 4979 3752 3933 4023 3102 6889 Ultimate
elongation % MD 655 601 603 630 698 839 TD 885 782 781 758 812 765
100% modulus psi MD 737 570 663 574 404 385 TD 532 416 484 509 299
535 300% modulus psi MD 1423 1055 1202 1044 683 638 TD 797 622 724
763 439 1003 Elmendorf Tear g/mil MD 81.9 24.9 26.9 31.7 16.1 80.6
TD 128.3 22.2 25.8 51.4 47.2 130.8 Impact resistance in-lbf/mls 4.7
no failure no failure no failure no failure No failure Cyclic
hysteresis to 100% extension Stress at 100% psi MD 475 466 492 511
338 444 extension TD 358 387 379 399 254 277 Recoverable energy %
MD 33.4 41.6 42.8 43.3 64.1 48.1 after 1 cycle TD 32.6 44.3 42.3
41.6 68.3 63 Hysteresis set @ 1 % MD 29.3 18.5 17 15 11 11 cycle TD
36.1 16.4 18.5 19.1 11.7 9.9 Cyclic hysteresis to 300% extension
Stress at 300% psi MD 958 941 818 987 504 667 extension TD 539 554
458 568 384 462 Recoverable energy % MD 13.5 19.3 18.3 18.6 50.7
40.1 after 1 cycle TD 16 23.5 21.8 22.3 57.8 51.5 Hysteresis set @
1 % MD 190 133 141 141 37 32.7 cycle TD 186 125 139 134 34.6
27.4
Example 3
[0053] In this example three different block copolymers were
compounded with varying amounts of a propylene homopolymer (Valtec
HH442H PP), a low-density polyethylene (Petrothene NA601-04) and
two different resins (Regalite R-1125 and Kristalex F-100).
Regalite R-1125 is a midblock-compatible resin, and Kristalex F-100
is a styrene containing end block resin. The block copolymers were
controlled distribution block copolymers #14 and #15, and a
selectively hydrogenated SBS block copolymer (KRATON G 1657).
[0054] The compounds were formed into fibers and tested. Table 3
below shows the compounds used and the test results. As shown in
Table 3 Polymers 14 and 15 exhibit lower permanent set and retain
their properties better under stress, as shown by the stress-decay
values, than normal SEBS triblock copolymers. This is true for
simple blends with LDPE and PP (examples 3-1 to 3-6) and in more
complex formulations with resins (examples 3-7 and 3-8).
5 TABLE 3A Compound Number Formulation, % weight 3-1 3-2 3-3 3-4
3-5 3-6 Kraton G-1657 75 75 Polymer #14 75 75 Polymer #15 75 75
Valtec HH442H PP 25 25 25 Petrothene NA601-04 LDPE 25 25 25 MFR
(230.degree. C./2.16 kg) 29 10.2 9.5 22 7.6 7.3 Fiber Data 50%
modulus, MPa 1.5 1.70 1.77 3.5 2.32 4.10 100% modulus, MPa 1.8 2.08
2.14 3.8 3.19 5.10 50% modulus at 1.33 1.43 1.49 2 2.16 3.66
40.degree. C., MPa 50% modulus at 40.degree. C. after 0.72 0.83
0.92 0.51 1.10 1.69 2 hrs Mpa Stress-decay, (%) 46 42 38 75 49 54
Permanent set (%) 12 10 11 16 11.5 21
[0055]
6 TABLE 3B Compound Number Formulation, % weight 3-7 3-8 Kraton
G-1657 Polymer #14 65 Polymer #15 65 Valtec HH442H PP 15 15
Petrothene NA601-04 LDPE Regalite R-1125 resin 10 10 Kristalex
F-100 resin 10 10 MFR (230.degree. C./2.16 kg) 12.4 11.5 Fiber Data
50% modulus, Mpa 1.39 1.68 100% modulus, Mpa 1.85 2.23 50% modulus
at 40.degree. C., MPa 1.30 1.43 50% modulus at 40.degree. C. after
2 hours, 0.79 0.89 Mpa Stress-decay (%) 39 38 Permanent set (%) 7.5
8.5
Example 4
[0056] In this example three different block copolymers were
compounded with mineral oil (Drakeol 34 mineral oil) and crystal
polystyrene (EA3000). The block copolymers were controlled
distribution block copolymers #3 and #4, and a selectively
hydrogenated SBS block copolymer (GRP 6926). All three of the block
copolymers had approximately the same molecular weights for the end
blocks and mid block. The various components were compounded and
then formed into films, and tested. The amounts are expressed in
percent weight. The various formulations and test results are shown
below in Table 4. As shown in Table 4 the modulus and hysteresis
values for the comparison example 4-1 vary by almost a factor of
two between the machine direction, MD, and transverse direction,
TD. This indicates a high degree of orientation during film casting
resulting in film with highly anistropic properties and dimensional
instability. By comparison examples 4-2 and 4-3 show a much smaller
difference in Modulus, recoverable energy and permanent set at all
elongations between the MD and TD directions. The values of
recoverable energy and permanent set in the MD for examples 4-2 and
4-3 are surprisingly low, indicating a much more elastic film than
a traditional SEBS triblock copolymer.
7 TABLE 4A Compound Number 4-1 4-2 4-3 Formulation % % % GRP 6926
SEBS 58.4 Polymer #3 58.83 Polymer #4 58.83 G1650 Drakeol 34
mineral oil 23.66 23.81 23.81 EA3000 Polystyrene 17.94 17.35 17.35
Tensile Max. Stress, psi TD 3716 3503 3580 Max. Stress, psi MD 3151
3831 3196 Ultimate Elongation, % TD 931 790 708 Ultimate
Elongation, % MD 829 756 656 50% Modulus, psi TD 118 103 96 50%
Modulus, psi MD 271 119 104 100% Modulus, psi TD 148 138 129 100%
Modulus, psi MD 341 165 148 200% Modulus, psi TD 210 210 200 200%
Modulus, psi MD 480 271 257 300% Modulus, psi TD 291 327 324 300%
Modulus, psi MD 630 447 458 500% Modulus, psi TD 593 913 1030 500%
Modulus, psi MD 1080 1270 1393 100% TD Hysteresis (75 F) (10
in/min) Stress @ 100% extension, psi 136.4 212.5 144.8 Recoverable
energy @ cycle 1, % 79.4 89.1 88.6 Hysteresis set @ cycle 1, % 4.9
4.7 4.9 100% MD Hysteresis (75 F) (10 in/min) Stress @ 100%
extension, psi 379.5 144.7 175.5 Recoverable energy @ cycle 1, %
46.3 86.4 85.5 Hysteresis set @ cycle 1, % 8.7 4.9 4.8
[0057]
8 TABLE 4B Compound Number 4-1 4-2 4-3 % % % 200% TD Hysteresis (75
F) (10 in/min) Stress @ 200% extension, psi 231.7 225.2 166.9
Recoverable energy @ cycle 1, % 73.3 88.9 87.3 Hysteresis set @
cycle 1, % 8.6 7.4 8.9 200% MD Hysteresis (75 F) (10 in/min) Stress
@ 200% extension, psi 610.8 301.5 223.7 Recoverable energy @ cycle
1, % 40.3 82.8 81 .3 Hysteresis set @ cycle 1, % 16.4 7.5 8.7 300%
TD Hysteresis (75 F) (10 in/min) Stress @ 200% extension, psi 278.6
298.3 347.2 Recoverable energy @ cycle 1, % 68.2 87.3 85 Hysteresis
set @ cycle 1, % 13.2 9.1 11.1 300% MD Hysteresis (75 F) (10
in/min) Stress @ 200% extension, psi 609.6 436.7 541.7 Recoverable
energy @ cycle 1, % 36.5 78 75.2 Hysteresis set @ cycle 1, % 25.4
9.6 11.3 Stress Relaxation @ 150%, TD (20 in/min) @ 100 F for 60
min Max Stress, psi 196.4 152.8 140.62 Stress @ 1 hr, psi 152.7 128
115.2 % Relaxation, % 22 16.2 18.1 Stress Relaxation @ 150%, MD (20
in/min) @ 100 F for 60 min. Max Stress, psi 395 175 183 Stress @ 1
hr, psi 269 142 122 % Relaxation, % 32 18.9 33.44
Example 5
[0058] In this example two different controlled distribution block
copolymers (#13 and #3) were compounded with two different ethylene
styrene interpolymers, which interpolymers were made with a
metallocene catalyst and had a random structure. These
interpolymers were Dow 2900TE having a styrene content of 34.2% w
and Dow 2901 TE, having a styrene content of 72.7% w. The various
components were mixed in a Brabender mixer and then formed into
compression-molded films. The various formulations and results are
shown below in Table 5. As shown in Table 5 the addition of 2900TE
to Polymer #3 increases strength across the complete composition
range from 90/10 to 10/90 while retaining high elongation.
Surprisingly, Examples 5-2 through 5-4 are transparent with
excellent hysteresis recovery and low permanent set. The higher
styrene content of 2901 TE produces opaque compounds (examples 5-8
through 5-13) that still retain high strength and elongation across
the range. The addition of polymer #13 to 2900TE, examples 5-15 to
5-17, decreases permanent set and improves hysteresis recovery and
elongation without loss of tensile strength. Examples 5-2 through
5-6 have the unexpected benefit of having higher tensile strength
than the two polymers of which they are composed.
9 TABLE 5A Molded Films FORMULATION(% weight): 5-1 5-2 5-3 5-4 5-5
5-6 5-7 Polymer #13 Polymer #3 100 90 80 50 30 20 10 2900 TE 10 20
50 70 80 90 2901 TE AO 330 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Properties:
Stress-Strain Max. Stress, psi 4106.0 6118 6088 8014 6494 6647 5901
Ultimate Elongation, % 789 840 829 794 739 741 695 50% Modulus, psi
236 285 395 314 454 485 466 100% Modulus, psi 308 346 464 408 566
604 599 200% Modulus, psi 459 480 624 599 785 849 862 300% Modulus,
psi 680 672 848 891 1159 1254 1302 500% Modulus, psi 1402 1501 1898
2192 2816 2793 3071 100% Hysteresis: Max. stress, psi 372.9 271.3
346.2 363.9 452 491.9 515.7 Perm. Set, % 7.5 7.4 8.6 9.7 10.3 10.3
10.4 1st Cycle Recovery, % 67.7 74 67.7 66.4 63.1 62.5 60.7 Load
Stress 50% ext., psi 297 228 284 286 356 387 408 Unload Stress 50%
ext., psi 197 168 187 177 204 218 221 Stress @ 50% Ext.2nd load,
psi 214 186 215 222 265 287 298 Stress @ 50% Ext.2nd Unload, psi
190 163 180 170 195 208 210 2nd Cycle Recovery, % 90.5 89.7 87.2
82.3 80.4 79.8 78.6 300% Hysteresis: Max. stress, psi 500.4 533.6
537.6 711.8 864.3 914.4 968.2 Perm. Set, % 15.4 20.1 26.6 53.8 79.1
89.4 102 1st Cycle Recovery, % 69.4 65.1 58.8 43.7 34.8 32.7 29.9
Load Stress 50% ext., psi 215.4 234.3 240.4 290.7 379.7 404.6 429.8
Unload Stress 50% ext., psi 97.4 81.7 60.2 n/a n/a n/a n/a 100%
Cyc-1 Load Stress, psi 267.7 282.7 289.5 366.1 473.9 506.3 533.4
100% Stress Cyc-1 Unload, psi 161.6 152.6 129.9 78.8 39.8 22.2
n/a
[0059]
10 TABLE 5B Molded Films FORMULATION(% weight): 5-8 5-9 5-10 5-11
5-12 5-13 Polymer #13 Polymer #3 90 80 50 30 20 10 2900 TE 2901 TE
10 20 50 70 80 90 AO 330 0.2 0.2 0.2 0.2 0.2 0.2 Properties:
Stress-Strain Max. Stress, psi 4721 5450 4089 4121 4581 4820
Ultimate Elongation, % 749 689 443 398 396 376 50% Modulus, psi 328
282 252 329 364 371 100% Modulus, psi 392 350 357 458 531 592 200%
Modulus, psi 550 534 719 968 1218 1534 300% Modulus, psi 790 862
1748 2569 3056 3349 500% Modulus, psi 1842 2584 n/a N/A N/A N/A
100% Hysteresis: Max. stress, psi 317.3 292.6 355.5 359 426.6 555.6
Perm. Set, % 11.4 15.2 24.7 31.8 33.3 40 1st Cycle Recovery, % 66.6
62.1 50.4 42.7 37.9 30 Load Stress 50% ext., psi 256 240 254 243
289 371 Unload Stress 50% ext., psi 168 144 115 83 81 60 Stress
@50% Ext.2nd load, psi 196 186 223 222 247 281 Stress @50% Ext.2nd
Unload, psi 160 135 100 59 54 31 2nd Cycle Recovery, % 85.5 79 57.8
46.1 43.1 38.5 300% Hysteresis: Max. stress, psi 648.4 788.3 2073.7
2315.6 2849.1 2735.3 Perm. Set, % 26.4 32.9 53 69.2 78.2 95.2 1st
Cycle Recovery, % 60.1 55.7 35.5 30.4 26.8 22.7 Load Stress 50%
ext., psi 260.5 274 269.8 281.7 337.7 360.2 Unload Stress 50% ext.,
psi 71.1 53.4 n/a n/a n/a n/a 100% Cyc-1 Load Stress, psi 321.6
330.7 366.7 398 487.2 528.5 100% Stress Cyc-1 Unload, psi 154.9 144
112.7 73.8 59.9 14.2
[0060]
11 TABLE 5C Molded Films FORMULATION(% weight): 5-14 5-15 5-16 5-17
5-18 5-19 Polymer #13 100 30 20 10 Polymer #3 2900 TE 70 80 90 100
2901 TE 100 AO 330 0.2 0.2 0.2 Properties: Stress-Strain Max.
Stress, psi 5260.5 6232 6379 5487 5916 4209 Ultimate Elongation, %
714.5 722.5 703 675 662 302 50% Modulus, psi 497.5 495.5 522 534
438 372 100% Modulus, psi 543 607.5 649 659.5 582 626 200% Modulus,
psi 772.5 851.5 916 927.5 876 1851 300% Modulus, psi 1170 1254 1379
1364 1344 n/a 500% Modulus, psi 2611 2727 3010 2872 2932 n/a 100%
Hysteresis: Max. stress, psi 490.4 468.2 489 532.3 543.6 613.8
Perm. Set, % 20.4 15 14.1 14.5 13 40.9 1st Cycle Recovery, % 39.4
54.6 55.2 53.6 55.3 30.5 Load Stress 50% ext., psi 456 373 389 423
424 366 Unload Stress 50% ext., psi 162 178 187 195 201 54 Stress @
50% Ext.2nd load, psi 263 265 280 298 295 278 Stress @ 50% Ext.2nd
Unload, psi 152 167 178 186 191 29 2nd Cycle Recovery, % 67 73.7
73.8 73 75.1 39.3 300% Hysteresis: Max. stress, psi 921 933.1 943.8
1046.2 1013.2 *samples broke, exceeded limits Perm. Set, % 42.3
93.5 102.2 108.3 113.6 1st Cycle Recovery, % 38.9 30 29.5 28.3 28.3
Load Stress 50% ext., psi 452.1 408 413.5 460.7 409.7 Unload Stress
50% ext., psi 25.2 n/a n/a n/a n/a 100% Cyc-1 Load Stress, psi 487
500.1 511.1 569.1 526.3 100% Stress Cyc-1 Unload, psi 119.5 13.9
6.5 n/a n/a
Example 6
[0061] In this example one controlled distribution block copolymer
(#9) was compared against a selectively hydrogenated SBS block
copolymer (KRATON G 1651) in various compounds with extending oil
and polypropylene homopolymer. The various formulations and results
are shown below in Table 6. As shown in Table 6, compositions made
with polymer #9 have much improved melt flows compared with
compositions made with G-1651. Surprisingly, the tensile strengths
of compositions made with polymer #9 are almost the same in the
machine and transverse directions in the mold when compared to
G-1651 compositions. This means that parts formed by injection
molding or extrusion will fill the mold better, have much less
tendency to warp when exposed to heat, and will have more uniform
properties when Polymer #9 is substituted for G-1651. This
stability means they will have opportunities for use in medical
applications.
12 TABLE 6 Compound # 6-1 6-2 6-3 6-4 6-5 6-6 Polymer Type
Formulation #9 G-1651 #9 G-1651 #9 G-1651 Polymer phr 100 100 100
100 100 100 PP Pm6100 phr 25 25 50 50 75 75 Oil phr 90 90 140 140
90 90 Properties MFR 200.degree. C./5 kg g/10 min 5.6 0.1 120 26 30
7 Hardness Shore A 30 sec 43 55 53 61 82 85 Resilience % 52 55 47
46 46 43 Din Abrasion mm3 285 110 244 95 146 65 Tensile properties
Mod 300% MD MPa 2.5 4 2.5 4 5.9 7 Mod 300% PMD MPa 2.2 3 2.4 3 5.2
5 Tensile Strength MD MPa 6.6 4 3 5 8.5 10 Tensile Strength PMD MPa
8.1 13 2.9 12 9.6 21 Elongation at Break MD % 700 330 450 510 520
500 Elongation at Break PMD % 805 780 470 790 615 805 Trouser tear
MD kN/m 9.6 7 6.9 9 17.5 18 Trouser tear PMD kN/m 8.9 8 7.8 10 23
21
Example 7
[0062] In this example two different controlled distribution block
copolymers (#11 and #9) were compared against two different
selectively hydrogenated SBS block copolymers (KRATON G 1651 and
1654) in oiled compounds. The extending oil used was Primol 352. To
the oil and polymer were added various other components including
polypropylene, poly(phenylene oxide) (Blendex HPP857), polystyrene,
syndiotactic polystyrene (MA405), cyclic olefin copolymer (Topas
6017) and ABS (Terluran 967 K). The various formulations and
results are shown below in Table 7. As shown in Table 7
compositions based on polymers #9 and 11 are more isotropic than
the comparison polymer while maintaining a good balance of
properties. They can also be blended with a variety of engineering
thermoplastics to yield a good balance of isotropic properties.
13 TABLE 7A Compound 7-1 7-2 7-3 7-4 7-5 7-6 7-7 7-8 7-9 Polymer
#11 100 100 100 100 100 100 Polymer #9 100 G1651 100 G1654 100
Primol 352 80 80 80 80 80 110 110 110 110 PP (MFR = 5.5) 45 45 45
45 PPO (Blendex HPP857) 40 PS 144C 40 Syndiotactic PS (MA 405) 40
COC (Topas 6017) 40 ABS (Terluran 967 K) 40 Presence of IPN no no
no yes no yes yes yes yes Hardness, Shore A 74 50 40 52 50 59 61 64
63 30 sec Compression set, % 70.degree. C./24 hrs 65 73 84 82 83
54/56 56/65 42 48/50 100.degree. C./24 hrs 97 100 100 100 100 84 97
62 81
[0063]
14 TABLE 7B Compound 7-1 7-2 7-3 7-4 7-5 7-6 7-7 7-8 7-9 Stress
strain properties MD 300% Modulus, MPa 4.9 5.3 4.7 3 4.8 3.3 3.8
3.9 4.2 Ts at break MPa 5.2 6.5 7.8 7.4 5.5 4.8 5.5 5.7 5.3
Elongation at break 350 400 470 650 550 560 580 570 460
Delamination no no no no yes no no no no PMD 300% Modulus, MPa 5.3
2.9 3.1 2.2 3.2 2.7 2.9 2.7 3 Ts at break MPa 6.5 14.2 11 9.3 6.7
4.5 4.8 13.3 13 Elongation at break 445 740 670 750 750 650 640 900
900 Delamination no no no no yes no no no no Anisotropy 1.2 2.2 1.4
1.3 1.2 0.94 0.9 2.3 2.5 (TSpmd/TSmd) Angle Tear Strength, kN/m Md
nm 27 24 26 28 22 25 30 30 Delamination -- no minor no yes no no no
no Pmd nm 37 32 26 32 22 25 35 35 Delamination -- no minor no yes
no no no no
Example 8
[0064] In this example three different controlled distribution
block copolymers (#3, #4 and #5) were compared against a
selectively hydrogenated SBS block copolymer (KRATON G 1651) in
formulations comprising polymer, polypropylene (PP 5A15H),
extending oil (Drakeol 34) and silica. These formulations are
intended for use as cap seals for screwed containers. The compounds
mentioned in Table 8 were prepared by preblending the raw materials
then mixing under heat and shear until a uniform blend was
achieved. Blending viscosity for compounds with polymers 3, 4 and 5
was lower than for G1651 compound. Each compound was then molded
under heat and pressure to make a plaque of uniform thickness.
Samples from these plaques were tested on a mechanical properties
instrument, the results being found in Table 8.
[0065] Polymers 3, 4 and 5 show isotropic behavior for mechanical
properties, but G 1651 does not. Polymer 5 molecular weight is less
than G 1651 by 50,000, yet exhibits the same tensile and elongation
properties. Modulus for polymers 3,4 and 5 are slightly higher than
that of G 1651, indicating that the compound is slightly stiffer.
Coefficient of friction shows that increasing the amount of styrene
in the midblock lowers the surface friction of the molded part.
[0066] The advantages of compounds made with polymers 3, 4 and 5
include:
[0067] 1. Lower blending viscosity results in easier mold
processing
[0068] 2. Isotropic behavior allows dimensional stability in molded
parts
[0069] 3. Increase in tensile, elongation and modulus allows for
use of less polymer in compounds
[0070] 4. Decrease in coefficient of friction allows for use in
applications where low friction surfaces are desirable, such as
bottle cap seals.
15 TABLE 8 Compound # 8-1 8-2 8-3 8-4 Polymer Type Formulation
(parts by weight) Unit Direction G-1651 #3 #4 #5 Polymer 100 100
100 100 Drakeol 34 100 100 100 100 PP5A15H 34 34 34 34 Silica 41 41
41 41 Property Tensile Properties Tensile psi MD 810 629 673 1378
TD 1343 619 636 1440 Ultimate elongation % MD 616 646 686 858 TD
872 740 599 883 100% modulus psi MD 207 297 232 228 TD 195 230 266
228 300% modulus psi MD 404 453 363 452 TD 384 381 421 456 COF
Static 2.05 1.59 1.05 0.823 Dynamic 2.03 1.15 1.15 0.698
Example 9
[0071] In this example two different controlled distribution block
copolymers (#15 and #16) were compared with KRATON FG-1901 in
blends with Nylon 6,6 (Zytel 101) at 15 and 20% by weight in a twin
screw extruder. Polymer #16 was prepared by maleating Polymer #15
to a level of 1.7% weight bound maleic anhydride in a Bergstroff
twin screw extruder. KRATON FG 1901 is an S-EB-S block copolymer
that was maleated to a similar level of 1.7% weight. The blends
were injection molded and the impact strength was measured using an
Izod impact tester. Samples were taken both from the blind end of
the mold and the gate end of the mold to minimize molding
effects.
[0072] As shown in Table 9, the addition of maleic anhydride
dramatically improves the ability of Polymer #15 to toughen Nylon
6,6. The greater toughness presented by the maleated Polymer #15
might allow less modifier to be used to achieve the same toughness
compared to available materials.
16TABLE 9 Formulation (% weight) 9-1 9-2 9-3 9-4 9-5 Polymer # 15
20 Polymer # 16 15 20 KRATON FG 1901 15 20 Nylon 6,6 80 85 80 85 80
Notched Izod Impact Test _(foot pounds per inch) Gate end 2.05 20.7
25.1 13.2 21.2 Blind end 2.08 23.6 25.9 13.5 23.1
Example 10
[0073] In this example we compared a controlled distribution
copolymers (#14) with KRATON G 1650 in an experiment to prepare
dipped articles. The method employed was as follows: first the
polymer was dissolved in toluene. If needed, plasticizer was added
to control viscosity. The solution was filtered through 100 mesh
metal filter. Then a glass tube (diameter 25 mm, L=25 cm) was
immersed in the solution. The glass tube was removed from the
solution at an appropriate speed to obtain a homogeneous film on
the tube. The solvent was allowed to evaporate. The typical
evaporation time for toluene at 45-50.degree. C. is 5 minutes. Next
the glass tube was cooled to room temperature. The dipping sequence
was repeated as needed. After the last dip, the solvent was allowed
to evaporate completely (1-2 hours at 45-50.degree. C.). The tube
was cooled down and the film removed carefully from the glass tube.
Tensile Testing was conducted according to ISO 4074-9 after cutting
circular test-samples from the samples.
[0074] As shown in Table 10, Polymer #14 exhibits an advantaged
combination of tensile strength and set at break.
17 TABLE 10 Sample ID 10-1 10-2 10-3 10-4 10-5 Polymer 14 14 G1650
G1650 G1650 Concentration % w 13 10 15 15 15 Brookfield viscosity
250 150 375 370 365 Oil content phr 0 25 0 25 50 PS MW k 10 10 10
10 10 PSC eff. % w 20 16 30 24 20 Number of dips 2-3 3 2 2 2
Thickness micro-m 50 50 100 75 80 Stress 100% MPa 1.8 1.0 1.6 1.5
1.3 Stress 300% MPa 3.8 1.9 3.1 2.6 2.2 Elongation % 500 550 450
650 810 Force N 30 25 35 60 65 Tensile strength MPa 24 18 12 30 27
Set after break % 3 5 6 8 15
Example 11
[0075] In this example we compared two different controlled
distribution block copolymers (#2 and #3) with KRATON G-1730, a
selectively hydrogenated S-I-S-I tetra block copolymer in various
compounds useful in personal hygiene articles. Some compounds only
contained the controlled distribution polymer or G-1730 plus
polyethylene (PE NA601), while other compounds also contained a
resin (Regalrez 1126).
[0076] The first set of compounds (numbers 1 to 6) were prepared in
the brabender mixing head on small scale. Following that larger
amounts of the control formulation containing G-1730 and one other
controlled distribution copolymer compound (compound #7 and 8) were
compounded on a twin screw extruder. The pellets were then
transformed into film on a cast film line. The properties of those
films were measured in the machine (MD) and transverse (TD)
directions. The examples shown in Table 11 reveal that the polymers
of the present invention give much higher modulus values while
retaining the other good properties of the control compound. Those
higher modulus values are a result of the stiffer stretch of the
inventive polymers and allow elastic laminate constructions having
higher force or allow the same laminate to be made more efficiently
with less elastomer. The films made form the present invention
surprisingly have much greater tear strength than the control
films.
18 TABLE 11A Compounds: 1 2 3 4 5 6 Polymer G-1730 #2 #3 G-1730 #2
#3 Polymer 68% 68% 68% 84.80% 84.80% 84.80% Regalrez 1126 20% 20%
20% PE NA601 11.80% 11.80% 11.80% 15% 15% 15% AO 330 0.20% 0.20%
0.20% 0.20% 0.20% 0.20% Properties (from plaques): Stress-Strain
Max. Stress at 2090 3169 3255 1620 2859 2683 Break, psi Strain at
1083 1057 895 927 1050 690 Break, % 100% 141 159 165 231 300 314
Modulus, psi 200% 189 201 236 295 361 428 Modulus, psi 300% 250 256
321 382 440 580 Modulus, psi 500% 427 443 605 651 663 1165 Modulus,
psi 100% Hysteresis Perm. Set, % 8.2 8.9 7.4 10.9 13.9 13.7 1st
Cycle 79.4 76.9 83.3 68.8 60.5 61.9 Recovery, %
[0077]
19 TABLE 11B Compounds 7 8 Polymer #3 G-1730 Polymer 68% 68%
Regalrez 1126 20% 20% PE NA601 11.80% 11.80% AO 330 0.20% 0.20
Properties (from films): MD TD MD TD Stress-Strain Max. Stress at
Break, 3635 3124 3213 1924 psi Strain at Break, % 769 773 888 787
100% Modulus, psi 168 137 122 106 200% Modulus, psi 212 175 158 139
300% Modulus, psi 273 243 211 189 500% Modulus, psi 357 336 281 255
689 661 535 498 100% Hysteresis Perm. Set, % 8.7 6.6 6.5 7.2 1st
Cycle Recovery, % 69.4 78.7 78.8 78.8 98 103 84 58 300% Hysteresis:
Perm. Set, % 31.1 16.9 1st Cycle Recovery, % 56.8 71.3 100% Stress
Cyc-1 85.2 80.5 Unload, psi Stress Relaxation @ 150% Strain Max.
Stress, psi 196 153 Stress @ End of Test, 162 116 psi % Relax @
30', % 18 25 Elmendorff tear: Tear strength(g/mils) 105.7 112.4 85
77
Example #12
[0078] This example is similar to Example #6, in that one
controlled distribution block copolymer (#9) was compared against a
selectively hydrogenated SBS block copolymer (KRATON G 1654) in a
compound with extending oil and polypropylene homopolymer. The
results are shown in Table 12. As shown in Table 12, the
composition with Polymer #9 has much improved melt flows compared
to compositions made with G-1654. Surprisingly, the compression set
of the two compounds are nearly the same. This means that the
compound made with Polymer #9 can be much more easily molded than
the compound containing G-1654 while retaining approximately the
same properties.
20TABLE 12 Formulation (parts by weight) 100 pbw Block Copolymer
110 pbw Plasticiser (Primol 352) 45 pbw Polypropylene (MFR = 5.5)
0.2 pbw Irganox 1010 0.8 pbw Irganox PS 800 Extrusion conditions
(W&Pfl ZSK 25) Werner Pfleiderer ZSK 25 Spiral flows
conditions: Temperature of melt = 190.degree. C./mould = 30.degree.
C., Injection time: 3 sec Polymer G1654 #9 Spiral Flow, degrees 500
bars 450 670 750 bars 670 890 900 bars 790 980 MFR, (g/10 min)
230.degree. C./2.16 kg 1 25 200.degree. C./5 kg 4 60 IPN test in
toluene PP content (% w) 25 20 Compression set % 23 C/72 hrs 70
C/24 hrs 54 48 100 C/24 hrs 81 84 Hardness, Shore A 63 59 DIN
Abrasion, mm3 90 325 Oil bleed-out No No Transparency 3 1
* * * * *