U.S. patent application number 14/350170 was filed with the patent office on 2014-08-28 for artificial turf yarn.
The applicant listed for this patent is Selim Bensason, Peter Sandkuehler. Invention is credited to Selim Bensason, Peter Sandkuehler.
Application Number | 20140242304 14/350170 |
Document ID | / |
Family ID | 45470586 |
Filed Date | 2014-08-28 |
United States Patent
Application |
20140242304 |
Kind Code |
A1 |
Sandkuehler; Peter ; et
al. |
August 28, 2014 |
ARTIFICIAL TURF YARN
Abstract
An artificial turf comprising a turf yarn prepared from an
ethylene-based polymer composition comprising less than or equal to
100 percent by weight of the units derived from ethylene; and less
than 30 percent by weight of units derived from one or more
.alpha.-olefin comonomers; wherein said ethylene-based polymer
composition is characterized by having a Comonomer Distribution
Constant of equal to or greater than 40, a vinyl unsaturation of
less than 100 vinyls per one million carbon atoms present in the
backbone of the ethylene-based polymer composition; a zero shear
viscosity ratio (ZSVR) equal to or greater than 1.75; a density in
the range of 0.915 to 0.930 g/cm.sup.3, a melt index (1.sub.2) in
the range of from 0.8 to 5 g/10 minutes, a molecular weight
distribution (M.sub.w/M.sub.n) in the range of from 2 to 3.6, and a
molecular weight distribution (M.sub.z/M.sub.w) equal to or less
than 3; and wherein the turf yarn exhibits one or more of the
following properties (a) shrink of less than 4.8%, and (b) curl of
less than 0.5 is provided.
Inventors: |
Sandkuehler; Peter;
(Tarragona, ES) ; Bensason; Selim; (Baech,
CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sandkuehler; Peter
Bensason; Selim |
Tarragona
Baech |
|
ES
CH |
|
|
Family ID: |
45470586 |
Appl. No.: |
14/350170 |
Filed: |
October 24, 2011 |
PCT Filed: |
October 24, 2011 |
PCT NO: |
PCT/ES2011/070733 |
371 Date: |
April 7, 2014 |
Current U.S.
Class: |
428/17 ;
526/352 |
Current CPC
Class: |
D01F 6/30 20130101; C08F
110/02 20130101; C08L 23/0815 20130101; C08F 210/16 20130101; E01C
13/08 20130101; C08F 210/14 20130101; C08F 2500/10 20130101; C08F
2500/10 20130101; C08F 2500/03 20130101; C08F 2500/18 20130101;
C08F 2500/17 20130101; C08F 2500/18 20130101; C08F 210/16 20130101;
C08F 2500/03 20130101; C08F 2500/12 20130101; C08F 2500/17
20130101; C08F 2500/12 20130101 |
Class at
Publication: |
428/17 ;
526/352 |
International
Class: |
E01C 13/08 20060101
E01C013/08 |
Claims
1. An artificial turf comprising: a turf yarn prepared from an
ethylene-based polymer composition comprising: less than or equal
to 100 percent by weight of the units derived from ethylene; and
less than 30 percent by weight of units derived from one or more
.alpha.-olefin comonomers; wherein said ethylene-based polymer
composition is characterized by having a Comonomer Distribution
Constant of equal to or greater than 40, a vinyl unsaturation of
less than 100 vinyls per one million carbon atoms present in the
backbone of the ethylene-based polymer composition; a zero shear
viscosity ratio (ZSVR) equal to or greater than 1.75; a density in
the range of 0.915 to 0.930 g/cm.sup.3, a melt index (1.sub.2) in
the range of from 0.8 to 5 g/10 minutes, a molecular weight
distribution (M.sub.w/M.sub.n) in the range of from 2 to 3.6, and a
molecular weight distribution (M.sub.z/M.sub.w) equal to or less
than 3; and wherein the turf yarn exhibits one or more of the
following properties (a) shrink of less than 4.8%, and (b) curl of
less than 0.5.
2. The artificial turf according to claim 1, wherein the turf yarn
exhibits a shrink of less than 4.5%.
3. The artificial turf according to claim 1, wherein the turf yarn
exhibits a curl of less than 0.4.
4. The artificial turf according to claim 1, wherein the
ethylene-based polymer composition has an I.sub.2 from 2 to 4.
5. The artificial turf according to claim 1, wherein the turf yarn
exhibits an elongation at break of at least 65%.
6. The artificial turf according to claim 1, wherein the turf yarn
exhibits a stability of 0.9 cN/dtex.
7. A method of preparing an artificial turf comprising: selecting
an ethylene-based polymer composition comprising: less than or
equal to 100 percent by weight of the units derived from ethylene;
and less than 30 percent by weight of units derived from one or
more .alpha.-olefin comonomers; wherein said ethylene-based polymer
composition is characterized by having a Comonomer Distribution
Constant of equal to or greater than 40, a vinyl unsaturation of
less than 100 vinyls per one million carbon atoms present in the
backbone of the ethylene-based polymer composition; a zero shear
viscosity ratio (ZSVR) equal to or greater than 1.75; a density in
the range of 0.915 to 0.930 g/cm.sup.3, a melt index (I.sub.2) in
the range of from 0.8 to 5 g/10 minutes, a molecular weight
distribution (M.sub.w/M.sub.n) in the range of from 2 to 3.6, and a
molecular weight distribution (M.sub.z/M.sub.w) equal to or less
than 3; and preparing a turf yarn from the ethylene-based polymer
composition.
8. The method according to claim 7, wherein the turf yarn exhibits
one or more of the following properties (a) shrink of less than
4.8%, and (b) curl of less than 0.5.
9. The method according to claim 7, wherein the turf yarn exhibits
a shrink of less than 4.5%.
10. The method according to claim 7, wherein the turf yarn exhibits
a curl of less than 0.4.
11. The method according to claim 7, wherein the ethylene-based
polymer composition has an I.sub.2 from 2 to 4.
12. The method according to claim 7, wherein the turf yarn exhibits
an elongation at break of at least 65%.
13. The method according to claim 7, wherein the turf yarn exhibits
a stability of 0.9 cN/dtex.
Description
FIELD OF INVENTION
[0001] The instant invention relates artificial turf.
BACKGROUND OF THE INVENTION
[0002] Artificial turf yarn prepared from polyethylene at densities
of about 0.900 g/cm.sup.3 typically exhibit higher shrink values
than those prepared from polyethylene having densities of about
0.935g/cm.sup.3. Lower density polyethylene provides the turf yarn
with higher durability, softness, and resiliency. Turf yarns
prepared from lower density polyethylene also exhibit higher
shrink. Turf yarns with high shrink shorten when the tufted carpet
is coated with a polyurethane or latex backing, thereby reducing
the pile height. In order to compensate for shrink, longer yarns
are tufted to account for the length reduction caused by high
shrink. Residual shrink in the yarn reflects potential energy and
stresses in the material which can be released by heat or time in
the installed artificial turf, which can cause yarn breaks or
curling.
SUMMARY OF THE INVENTION
[0003] The instant invention is an artificial turf and method of
preparing same. In one embodiment, the instant invention provides
an artificial turf comprising a turf yarn prepared from an
ethylene-based polymer composition comprising: less than or equal
to 100 percent by weight of the units derived from ethylene; and
less than 30 percent by weight of units derived from one or more
.alpha.-olefin comonomers; wherein said ethylene-based polymer
composition is characterized by having a Comonomer Distribution
Constant of equal to or greater than 40, a vinyl unsaturation of
less than 100 vinyls per one million carbon atoms present in the
backbone of the ethylene-based polymer composition; a zero shear
viscosity ratio (ZSVR) equal to or greater than 1.75; a density in
the range of 0.915 to 0.930 g/cm.sup.3, a melt index (I.sub.2) in
the range of from 0.8 to 5 g/10 minutes, a molecular weight
distribution (M.sub.w/M.sub.n) in the range of from 2 to 3.6, and a
molecular weight distribution (M.sub.z/M.sub.w) equal to or less
than 3; and wherein the turf yarn exhibits one or more of the
following properties (a) shrink of less than 4.8%, and (b) curl of
less than 0.5.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] For the purpose of illustrating the invention, there is
shown in the drawings a form that is exemplary; it being
understood, however, that this invention is not limited to the
precise arrangements and instrumentalities shown.
[0005] FIG. 1 is a schematic illustrating measurements used in
calculating curl.
DETAILED DESCRIPTION OF THE INVENTION
[0006] The instant invention is an artificial turf. The term
"artificial turf," as used herein, is a carpet-like cover having
substantially upright, or upright, polymer strands of artificial
turf yarn projecting upwardly from a substrate. The term
"artificial turf yarn" or "turf yarn" or "yarn" as used herein,
includes fibrillated tape yarn, co-extruded tape yarns, monotape
and monofilament yarn. A "fibrillated tape" or "fibrillated tape
yarn," is a cast extruded film cut into tape (typically about 1 cm
width), the film stretched and long slits cut (fibrillated) into
the tape giving the tape the dimensions of grass blades. A
"monofilament yarn" is extruded into individual yarn or strands
with a desired cross-sectional shape and thickness followed by yarn
orientation and relaxation in hot ovens. The artificial turf yarn
forms the polymer strands for the artificial turf.
[0007] The artificial turf comprises a turf yarn prepared from an
ethylene-based polymer composition comprising: less than or equal
to 100 percent by weight of the units derived from ethylene; and
less than 30 percent by weight of units derived from one or more
.alpha.-olefin comonomers; wherein said ethylene-based polymer
composition is characterized by having a Comonomer Distribution
Constant of equal to or greater than 40, a vinyl unsaturation of
less than 100 vinyls per one million carbon atoms present in the
backbone of the ethylene-based polymer composition; a zero shear
viscosity ratio (ZSVR) equal to or greater than 1.75; a density in
the range of 0.915 to 0.930 g/cm.sup.3, a melt index (I.sub.2) in
the range of from 0.8 to 5 g/10 minutes, a molecular weight
distribution (M.sub.w/M.sub.n) in the range of from 2 to 3.6, and a
molecular weight distribution (M.sub.z/M.sub.w) equal to or less
than 3; and wherein the turf yarn exhibits one or more of the
following properties (a) shrink of less than 4.8%, and (b) curl of
less than 0.5.
[0008] The ethylene-based polymer composition comprises (a) less
than or equal to 100 percent, for example, at least 70 percent, or
at least 80 percent, or at least 90 percent, by weight of the units
derived from ethylene; and (b) less than 30 percent, for example,
less than 25 percent, or less than 20 percent, or less than 10
percent, by weight of units derived from one or more .alpha.-olefin
comonomers. The term "ethylene-based polymer composition" refers to
a polymer that contains more than 50 mole percent polymerized
ethylene monomer (based on the total amount of polymerizable
monomers) and, optionally, may contain at least one comonomer.
[0009] The .alpha.-olefin comonomers typically have no more than 20
carbon atoms. For example, the .alpha.-olefin comonomers may
preferably have 3 to 10 carbon atoms, and more preferably 3 to 8
carbon atoms. Exemplary .alpha.-olefin comonomers include, but are
not limited to, propylene, 1-butene, 1-pentene, 1-hexene,
1-heptene, 1-octene, 1-nonene, 1-decene, and 4-methyl-l-pentene.
The one or more .alpha.-olefin comonomers may, for example, be
selected from the group consisting of propylene, 1-butene,
1-hexene, and 1-octene; or in the alternative, from the group
consisting of 1-hexene and 1-octene.
[0010] In one embodiment, ethylene-based polymer composition has a
comonomer distribution profile comprising a monomodal distribution
or a bimodal distribution in the temperature range of from
35.degree. C. to 120.degree. C., excluding purge.
[0011] Any conventional ethylene (co)polymerization reaction
processes may be employed to produce the ethylene-based polymer
composition. Such conventional ethylene (co)polymerization reaction
processes include, but are not limited to, slurry phase
polymerization process, solution phase polymerization process, and
combinations thereof using one or more conventional reactors, e.g.
loop reactors, stirred tank reactors, batch reactors in parallel,
series, and/or any combinations thereof.
[0012] In one embodiment, the ethylene-based polymer is prepared
via a process comprising the steps of: (a) polymerizing ethylene
and optionally one or more .alpha.-olefins in the presence of a
first catalyst to form a semi-crystalline ethylene-based polymer in
a first reactor or a first part of a multi-part reactor; and (b)
reacting freshly supplied ethylene and optionally one or more
.alpha.-olefins in the presence of a second catalyst comprising an
organometallic catalyst thereby forming an ethylene-based polymer
composition in at least one other reactor or a later part of a
multi-part reactor, wherein at least one of the catalyst systems in
step (a) or (b) comprises a metal complex of a polyvalent
aryloxyether corresponding to the formula:
##STR00001##
[0013] wherein M.sup.3 is Ti, Hf or Zr, preferably Zr;
[0014] Ar.sup.4 is independently in each occurrence a substituted
C.sub.9-20 aryl group, wherein the substituents, independently in
each occurrence, are selected from the group consisting of alkyl;
cycloalkyl; and aryl groups; and halo-, trihydrocarbylsilyl- and
halohydrocarbyl-substituted derivatives thereof, with the proviso
that at least one substituent lacks co-planarity with the aryl
group to which it is attached;
[0015] T.sup.4 is independently in each occurrence a C.sub.2-20
alkylene, cycloalkylene or cycloalkenylene group, or an inertly
substituted derivative thereof;
[0016] R.sup.21 is independently in each occurrence hydrogen, halo,
hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl,
alkoxy or di(hydrocarbyl)amino group of up to 50 atoms not counting
hydrogen;
[0017] R.sup.3 is independently in each occurrence hydrogen, halo,
hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl,
alkoxy or amino of up to 50 atoms not counting hydrogen, or two
R.sup.3 groups on the same arylene ring together or an R.sup.3 and
an R.sup.21 group on the same or different arylene ring together
form a divalent ligand group attached to the arylene group in two
positions or join two different arylene rings together; and
[0018] R.sup.D is independently in each occurrence halo or a
hydrocarbyl or trihydrocarbylsilyl group of up to 20 atoms not
counting hydrogen, or 2 R.sup.D groups together are a
hydrocarbylene, hydrocarbadiyl, diene, or poly(hydrocarbyl)silylene
group.
[0019] In general, the ethylene-based polymer composition may be
produced via a solution polymerization according to the following
exemplary process. All raw materials (ethylene, 1-octene) and the
process solvent (a narrow boiling range high-purity isoparaffinic
solvent commercially available under the tradename Isopar E from
ExxonMobil Corporation) are purified with molecular sieves before
introduction into the reaction environment. Hydrogen is supplied in
pressurized cylinders as a high purity grade and is not further
purified. The reactor monomer feed (ethylene) stream is pressurized
via mechanical compressor to a pressure that is above the reaction
pressure, approximate to 750 psig. The solvent and comonomer
(1-octene) feed is pressurized via mechanical positive displacement
pump to a pressure that is above the reaction pressure,
approximately 750 psig. The individual catalyst components are
manually batch diluted to specified component concentrations with
purified solvent (Isopar E) and pressurized to a pressure that is
above the reaction pressure, approximately 750 psig. All reaction
feed flows are measured with mass flow meters, independently
controlled with computer automated valve control systems.
[0020] The continuous solution polymerization reactor system
according to the present invention consist of two liquid full,
non-adiabatic, isothermal, circulating, and independently
controlled loops operating in a series configuration. Each reactor
has independent control of all fresh solvent, monomer, comonomer,
hydrogen, and catalyst component feeds. The combined solvent,
monomer, comonomer and hydrogen feed to each reactor is
independently temperature controlled to anywhere between 5.degree.
C. to 50.degree. C. and typically 40.degree. C. by passing the feed
stream through a heat exchanger. The fresh comonomer feed to the
polymerization reactors can be manually aligned to add comonomer to
one of three choices: the first reactor, the second reactor, or the
common solvent and then split between both reactors proportionate
to the solvent feed split. The total fresh feed to each
polymerization reactor is injected into the reactor at two
locations per reactor roughly with equal reactor volumes between
each injection location. The fresh feed is controlled typically
with each injector receiving half of the total fresh feed mass
flow. The catalyst components are injected into the polymerization
reactor through specially designed injection stingers and are each
separately injected into the same relative location in the reactor
with no contact time prior to the reactor. The primary catalyst
component feed is computer controlled to maintain the reactor
monomer concentration at a specified target. The two cocatalyst
components are fed based on calculated specified molar ratios to
the primary catalyst component. Immediately following each fresh
injection location (either feed or catalyst), the feed streams are
mixed with the circulating polymerization reactor contents with
static mixing elements. The contents of each reactor are
continuously circulated through heat exchangers responsible for
removing much of the heat of reaction and with the temperature of
the coolant side responsible for maintaining isothermal reaction
environment at the specified temperature. Circulation around each
reactor loop is provided by a screw pump. The effluent from the
first polymerization reactor (containing solvent, monomer,
comonomer, hydrogen, catalyst components, and molten polymer) exits
the first reactor loop and passes through a control valve
(responsible for maintaining the pressure of the first reactor at a
specified target) and is injected into the second polymerization
reactor of similar design. As the stream exits the reactor, it is
contacted with a deactivating agent, e.g. water, to stop the
reaction. In addition, various additives such as anti-oxidants, can
be added at this point. The stream then goes through another set of
static mixing elements to evenly disperse the catalyst deactivating
agent and additives. Following additive addition, the effluent
(containing solvent, monomer, comonomer, hydrogen, catalyst
components, and molten polymer) passes through a heat exchanger to
raise the stream temperature in preparation for separation of the
polymer from the other lower boiling reaction components. The
stream then enters a two stage separation and devolatilization
system where the polymer is removed from the solvent, hydrogen, and
unreacted monomer and comonomer. The recycled stream is purified
before entering the reactor again. The separated and devolatized
polymer melt is pumped through a die specially designed for
underwater pelletization, cut into uniform solid pellets, dried,
and transferred into a hopper.
[0021] The ethylene-based polymer composition useful in embodiments
of the inventive artificial turf is characterized by having a
Comonomer Distribution Constant (CDC) of equal to or greater than
40. All individual values and subranges of equal to or greater than
40 are included herein and disclosed herein; for example, the CDC
can be from a lower limit of 40, 80, 100, 150, 200, 250, 300, or
350. For example, the CDC of the ethylene-based polymer composition
may be from 40 to 400, or from 100 to 300, or from 100 to 200, or
from 40 to 80, or from 80 to 200 or from 80 to 400.
[0022] The ethylene-based polymer composition useful in embodiments
of the inventive artificial turf is characterized by having a vinyl
unsaturation of less than 100 vinyls per one million carbon atoms
present in the backbone of the ethylene-based polymer composition
(vinyls/1,000,000 C). All individual values and subranges from less
than 100 vinyls/1,000,000 C are included herein and disclosed
herein; for example, the amount of vinyl unsaturation can be from a
upper limit of 50, 60, 70, 80, 90 or 100 vinyls/1,000,000 C.
[0023] The ethylene-based polymer composition useful in embodiments
of the inventive artificial turf is characterized by having a total
unsaturation of less than or equal to 150 total unsaturations per
one million carbon atoms present in the backbone of the
ethylene-based polymer composition (total unsaturations/1,000,000
C). All individual values and subranges from less than or equal to
150 total unsaturations/1,000,000 C are included herein and
disclosed herein. For example, the amount of total unsaturation can
be less than or equal to 150, or less than or equal to 125, or less
than or equal to 100, or less than or equal to 70, or less than or
equal to 50/1,000,000 C.
[0024] The ethylene-based polymer composition useful in embodiments
of the inventive artificial turf is characterized by having a zero
shear viscosity ratio (ZSVR) equal to or greater than 1.75. All
individual values and subranges of equal to or greater than 1.75
are included herein and disclosed herein; for example, the ZSVR of
the ethylene-based polymer can be from a lower limit of 1.75, 2,
2.2, 2.4, 2.6, 2.8 or 2.9.
[0025] The ethylene-based polymer composition useful in embodiments
of the inventive artificial turf is further characterized by having
a density in the range of 0.915 to 0.930 g/cm.sup.3. All individual
values and subranges from 0.915 to 0.930 g/cm.sup.3 are included
herein and disclosed herein; for example, the density can be from a
lower limit of 0.915, 0.918, 0.920, 0.925, or 0.928 g/cm.sup.3 to
an upper limit of 0.918, 0.920, 0.925, 0.928, or 0.930 g/cm.sup.3.
For example, the density may be in the range of from 0.915 to 0.930
g/cm.sup.3, or from 0.902 to 0.928 g/cm.sup.3, or from 0.918 to
0.930 g/cm.sup.3.
[0026] The ethylene-based polymer composition useful in embodiments
of the inventive artificial turf is further characterized by having
a melt index (I.sub.2) in the range of from 0.8 to 5 g/10 minutes.
All individual values and subranges from 0.8 to 5 g/10 minutes are
included herein and disclosed herein; for example, the I.sub.2 can
be from a lower limit of 0.8, 1, 1.5, 2, 2.5, 3, 3.5, 4, or 4.5
g/10 minutes to an upper limit of 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5
g/10 minutes. For example, the I.sub.2 may be in the range of from
0.8 to 5, or from 1.5 to 5, or from 1 to 3.5, or from 2 to 4 g/10
minutes, or from 3 to 4 g/10 minutes.
[0027] The ethylene-based polymer composition useful in embodiments
of the inventive artificial turf is further characterized by having
a molecular weight distribution (M.sub.w/M.sub.n) in the range of
from 2 to 3.6. All individual values and subranges from 2 to 3.6
are included herein and disclosed herein; for example, the
M.sub.w/M.sub.n can be from a lower limit of 2, 2.2, 2.4, 2.6, 2.8,
3, 3.2, 3.4 or 3.5 to an upper limit of 2.1, 2.3, 2.5, 2.7, 2.9,
3.1, 3.3, 3.5, or 3.6. For example, the M.sub.w/M.sub.n may be in
the range of from 2 to 3.6, or in the alternative, the
M.sub.w/M.sub.n may be in the range of from 2 to 3, or in the
alternative, the M.sub.w/M.sub.n may be in the range of from 2.4 to
3.6, or in the alternative, the M.sub.w/M.sub.n may be in the range
of from 2.4 to 3.4,
[0028] The ethylene-based polymer composition useful in embodiments
of the inventive artificial turf is further characterized by having
a molecular weight distribution (M.sub.z/M.sub.w) in the range of
from less than 3. All individual values and subranges from less
than 3 are included herein and disclosed herein; for example, the
M.sub.z/M.sub.w can be from an upper limit of 2.4, 2.6, 2.8 or
3.
[0029] A turf yarn prepared from the ethylene-based polymer
exhibits one or more of the following properties: (a) shrink of
less than 4.8%, and (b) curl of less than 0.5.
[0030] In one embodiment, the ethylene-based polymer composition
comprises less than or equal to 100 parts, for example, less than
10 parts, less than 8 parts, less than 5 parts, less than 4 parts,
less than 1 parts, less than 0.5 parts, or less than 0.1 parts, by
weight of metal complex residues remaining from a catalyst system
comprising a metal complex of a polyvalent aryloxyether, as
described hereinabove, per one million parts of the ethylene-based
polymer composition. The metal complex residues remaining from the
catalyst system comprising a metal complex of a polyvalent
aryloxyether in the ethylene-based polymer composition may be
measured by x-ray fluorescence (XRF), which is calibrated to
reference standards. The polymer resin granules can be compression
molded at elevated temperature into plaques having a thickness of
about 3/8 of an inch for the x-ray measurement in a preferred
method. At very low concentrations of metal complex, such as below
0.1 ppm, ICP-AES (inductively coupled plasma-atomic emission
spectroscopy) would be a suitable method to determine metal complex
residues present in the ethylene-based polymer composition.
[0031] Any of the foregoing artificial turf yarns may include one
or more additives. Nonlimiting examples of suitable additives
include antioxidants, pigments, colorants, UV stabilizers, UV
absorbers, curing agents, cross linking co-agents, boosters and
retardants, processing aids, fillers, coupling agents, ultraviolet
absorbers or stabilizers, antistatic agents, nucleating agents,
slip agents, plasticizers, lubricants, viscosity control agents,
tackifiers, anti-blocking agents, surfactants, extender oils, acid
scavengers, and metal deactivators. Additives can be used in
amounts ranging from less than about 0.01 wt % to 10 wt % based on
the weight of the composition.
[0032] Nonlimiting examples of pigments include inorganic pigments
that are suitably colored to provide an aesthetic appeal including
various shades of green, white (TiO.sub.2, rutile), iron oxide
pigments, and any other color.
[0033] Examples of antioxidants are as follows, but are not limited
to: hindered phenols such as
tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydro-cinnamate)]
methane;
bis[(beta-(3,5-ditert-butyl-4-hydroxybenzyl)-methylcarboxyethyl)]sulphide-
, 4,4'-thiobis(2-methyl-6-tert-butylphenol),
4,4'-thiobis(2-tert-butyl-5-methylphenol),
2,2'-thiobis(4-methyl-6-tert-butylphenol), and thiodiethylene
bis(3,5-di-tert-butyl-4-hydroxy)hydrocinnamate; phosphites and
phosphonites such as tris(2,4-di-tert-butylphenyl)phosphite and
di-tert-butylphenyl-phosphonite; thio compounds such as
dilaurylthiodipropionate, dimyristylthiodipropionate, and
distearylthiodipropionate; various siloxanes; polymerized
2,2,4-trimethyl-1,2-dihydroquinoline,
n,n'-bis(1,4-dimethylpentyl-p-phenylenediamine), alkylated
diphenylamines, 4,4'-bis(alpha, alpha-demthylbenzyl)diphenylamine,
diphenyl-p-phenylenediamine, mixed di-aryl-p-phenylenediamines, and
other hindered amine antidegradants or stabilizers. Antioxidants
can be used in amounts of about 0.1 to about 5 wt % based on the
weight of the composition
[0034] Examples of processing aids include but are not limited to
metal salts of carboxylic acids such as zinc stearate or calcium
stearate; fatty acids such as stearic acid, oleic acid, or erucic
acid; fatty amides such as stearamide, oleamide, erucamide, or
n,n'-ethylenebisstearamide; polyethylene wax; oxidized polyethylene
wax; polymers of ethylene oxide; copolymers of ethylene oxide and
propylene oxide; vegetable waxes; petroleum waxes; non ionic
surfactants; and polysiloxanes. Processing aids can be used in
amounts of about 0.05 to about 5 wt % based on the weight of the
composition.
[0035] Examples of UV stabilizers and UV absorbers include but are
not limited to hindered amine light stabilizers, benzophenone,
benzotriazole, hydroxyphenyl triazine,
2-(2'-hydroxyphenyl)benzotriazoles, UVINOL 3000, TINUVIN P, IRGANOX
1098, UVINOL 3008, LAVINIX BHT, TINUVIN 320, IRGANOX 1010, IRGANOX
1076, and IRGAFOS 168. UVINOL, TINUVIN, IRGANOX AND IRGAFOS
products are available from BASF.
[0036] A turf yarn prepared from the ethylene-based polymer may
exhibit either or both of the defined shrink and curl
characteristics. For those embodiments in which the turf yarn
exhibits the specified shrink characteristic, all individual values
and subranges of less than 4.8% are included herein and disclosed
herein; for example, the shrink can be from an upper limit of 3.6%,
3.8%, 4%, 4.2%, 4.4%, 4.6% or 4.8%. For those embodiments in which
the turf yarn exhibits the specified curl characteristic, all
individual values and subranges of less than 0.5 are included
herein and disclosed herein; for example, the shrink can be from an
upper limit of 0.3, 0.34, 0.38, 0.4, 0.44, 0.48 or 0.5.
[0037] A turf yarn made from the ethylene-based polymer may
optionally exhibit several other characteristics. In some
embodiments, a turf yarn made from the ethylene-based polymer may
exhibit one or both of the following properties: (a) elongation at
break of at least 70%; and (b) stability of at least 0.9 cN/dtex.
All individual values and subranges from at least 70% are included
herein and disclosed herein; for example, the elongation at break
can be from a lower limit of 70%, 74, 78, 81, or 83%. Likewise, all
individual values and subranges from at least 0.9 cN/dtex are
included herein and disclosed herein; for example, the stability
can be from a lower limit of 0.9, 1.0, 1.02, 1.05, 1.08, 1.1, 1.12,
1.14, or 1.16.
[0038] In an alternative embodiment, the instant invention further
provides a method of preparing an artificial turf comprising
selecting an ethylene-based polymer composition comprising less
than or equal to 100 percent by weight of the units derived from
ethylene; and less than 30 percent by weight of units derived from
one or more .alpha.-olefin comonomers; wherein said ethylene-based
polymer composition is characterized by having a Comonomer
Distribution Constant of equal to or greater than 40, a vinyl
unsaturation of less than 100 vinyls per one million carbon atoms
present in the backbone of the ethylene-based polymer composition;
a zero shear viscosity ratio (ZSVR) equal to or greater than 1.75;
a density in the range of 0.915 to 0.930 g/cm.sup.3, a melt index
(1.sub.2) in the range of from 0.8 to 5 g/10 minutes, a molecular
weight distribution (M.sub.w/M.sub.n) in the range of from 2 to
3.6, and a molecular weight distribution (M.sub.z/M.sub.w) equal to
or less than 3; and preparing a turf yarn from the ethylene-based
polymer composition.
[0039] In an alternative embodiment, the instant invention provides
an artificial turf, and method of producing the same, in accordance
with any of the preceding embodiments, except that the turf yarn
exhibits one or more of the following properties (a) shrink of less
than 4.8%, and (b) curl of less than 0.5.
[0040] In an alternative embodiment, the instant invention provides
an artificial turf, and method of producing the same, in accordance
with any of the preceding embodiments, except that the turf yarn
exhibits a shrink of less than 4.5% (e.g., from 3.5% to 4.5%)
[0041] In an alternative embodiment, the instant invention provides
an artificial turf, and method of producing the same, in accordance
with any of the preceding embodiments, except that the turf yarn
exhibits a curl of less than 0.4 (e.g., from 0.25 to 0.4).
[0042] In an alternative embodiment, the instant invention provides
an artificial turf, and method of producing the same, in accordance
with any of the preceding embodiments, except that the
ethylene-based polymer composition has an I.sub.2 from 3 to 4.
[0043] In an alternative embodiment, the instant invention provides
an artificial turf, and method of producing the same, in accordance
with any of the preceding embodiments, except that the turf yarn
exhibits an elongation at break of at least 65%.
[0044] In an alternative embodiment, the instant invention provides
an artificial turf, and method of producing the same, in accordance
with any of the preceding embodiments, except that the turf yarn
exhibits a stability of 0.9 cN/dtex.
Artificial Turf Yarn Production
[0045] The turf yarn may be made using any appropriate process for
the production of artificial turf yarn from polymer compositions.
The following describes one such process.
[0046] Turf yarns may be made by extrusion. Typical turf yarn
extruders are equipped with a single PE/PP general purpose screw
and a melt pump ("gear pump" or "melt pump") to precisely control
the consistency of polymer volume flow into the die. Turf yarn dies
have multiple single holes for the individual filaments distributed
over a circular or rectangular spinplate. The shape of the holes
corresponds to the desired yarn crossection profile, including for
example, rectangular, dog-bone, and v-shaped. A standard spinplate
has 50 to 160 die holes of specific dimensions. Lines typically
have output rates from 150 kg/h to 350 kg/h.
[0047] The turf yarns are typically extruded into a water-bath with
typical die-water-bath distance of from 16 to 40 mm. Coated guiding
bars in the water redirect the yarn filaments towards the first
take off set of rollers. The linear speed of this set of rollers
typically vary from 15 to 70 m/min. The takeoff set of rollers can
be heated and used to preheat the yarn after the waterbath before
entering the oven.
[0048] A yarn is passed over this first set of rollers, and then
drawn through a heated air or water bath oven. The first oven is
either a hot air oven with co- or countercurrent hot air flow which
can be operated from 50 to 150.degree. C. or a hot water-oven
wherein the yarn is oriented at temperatures from 50 to 98.degree.
C. At the exit of the oven, the yarn is passed onto a second set of
rollers that are run at a different (higher or lower) speed than
the first set of rollers. The linear velocity ratio of the rollers
after the oven to the rollers in front of the oven is referred to
as either a stretching or relaxation ratio. In a three oven
process, there are a total of four sets of rollers; a first set of
rollers before the first oven, a second set of rollers between the
first and second oven, a third set of roller between the second and
third ovens, and a fourth set of rollers following the third
oven.
EXAMPLES
[0049] The following examples illustrate the present invention but
are not intended to limit the scope of the invention.
[0050] Each of Inventive Composition Examples (Inv. Comp. Ex.) 1-3
contained 100 wt % of an ethylene-based polymer composition.
Comparative Composition Example (Comp. Composition Ex.) 1 contained
100% ELITE 5230G (a polyethylene commercially available from The
Dow Chemical Company). Comparative Composition Example 2 contained
100% DOWLEX 2108G (a Linear Low Density Polyethylene commercially
available from The Dow Chemical Company). Comparative Composition
Example 3 contained 90 wt % ELITE 5230G and 10 wt % DOWLEX 2108G.
Tables 1-5 provide various properties for Inventive Composition
Examples 1-3 and Comparative Composition Examples 1-3.
TABLE-US-00001 TABLE 1 Mn Mp Mw Mz (g/mol) (g/mol) (g/mol) (g/mol)
Mw/Mn Mz/Mw Inv. Comp. 31799 56763 70176 129086 2.21 1.84 Ex. 1
Inv. Comp. 20900 34778 71948 167252 3.44 2.32 Ex. 2 Inv. Comp.
30203 54350 73442 144152 2.43 1.96 Ex. 3 Comp. 25592 62374 75116
152617 2.94 2.03 Composition Ex. 1 Comp. 27562 57635 88966 232743
3.23 2.62 Composition Ex. 2
TABLE-US-00002 TABLE 2 Density, g/cm.sup.3 I.sub.2 (g/10 min)
I.sub.10/I.sub.2 Inv. Comp. Ex. 1 0.920 4.0 7.2 Inv. Comp. Ex. 2
0.919 3.4 8.5 Inv. Comp. Ex. 3 0.918 3.4 7.0 Comp. Composition Ex.
1 0.916 4.0 6.9 Comp. Composition Ex. 2 0.935 2.6 7.2 Comp.
Composition Ex. 3* 0.918 3.7 Not available *Values for Comp.
Composition Ex. 3 were calculated based upon component polymer
values.
TABLE-US-00003 TABLE 3 Unsaturation unit/1,000,000 carbon Vinylene
Trisubstituted Vinyl Vinylidene Total Inv. Comp. 3 None 18 3 25 Ex.
1 detected (ND) Inv. Comp. 6 ND 39 3 49 Ex. 2 Inv. Comp. 4 ND 41 4
49 Ex. 3 Comp. 56 23 162 39 280 Composition Ex. 1 Comp. 24 7 286 24
342 Composition Ex. 2
TABLE-US-00004 TABLE 4 Half Half CDI Stdev (.degree. C.) Width
(.degree. C.) Width/Stdev CDC Inv. Comp. 0.766 11.518 5.553 0.482
158.9 Ex. 1 Inv. Comp. 0.830 8.846 15.936 1.801 46.0 Ex. 2 Inv.
Comp. 0.790 9.594 4.742 0.494 159.7 Ex. 3 Comp. 0.704 12.441 6.550
0.526 133.7 Composition Ex. 1 Comp. 0.950 9.655 5.018 0.520 182.8
Composition Ex. 2 Comp. 0.653 13.085 6.186 0.473 138.2 Composition
Ex. 3
TABLE-US-00005 TABLE 5 Mw(g/mol) ZSV (Pas) ZSVR Inv. Comp. Ex. 1
70176 2420 2.16 Inv. Comp. Ex. 2 71948 3485 2.85 Inv. Comp. Ex. 3
73442 2737 2.07 Comp. Composition Ex. 1 75116 2241 1.56 Comp.
Composition Ex. 2 88966 3374 1.27
Turf Yarn Production
[0051] Inventive Turf Yarn Examples (Inv. TY Ex.) 1-3 were prepared
from Inventive Composition Examples 1-3, respectively. Each of the
Inventive Turf Yarn Examples contained 93.5 percent by weight of
the Inventive Composition Example, 6 percent by weight of ARGUS
GREEN G16-130UV and 0.5 percent by weight of ARGUS ARX/41 PA01 LD
process aid (each of which are commercially available from Argus
Additive Plastics GbmH, Buren, Germany). The conditions of
monofilament formation and resulting monofilament properties are
shown in Table 6 below. Comparative Turf Yarn Example (Comp. TY
Ex.) 1 was prepared from 93.5 weight percent Comp. Composition Ex.
3, 6 weight percent ARGUS GREEN G16-130UV and 0.5 percent by weight
of ARGUS ARX/41 PA01 LD process aid. The additives were blended
with the polymer compositions prior to extrusion. Each of the Turf
Yarn Examples was prepared on a compact three oven extrusion line
from Oerlikon Barmag (Remscheid, Germany) as described hereinabove.
The specific conditions of the equipment used in preparing the Turf
Yarn Examples is provided in Table 6 below. Table 6 further
provides physical properties for each of the Turf Yarn
Examples.
TABLE-US-00006 TABLE 6 Comp. TY Inv. TY Inv. TY Inv. TY Ex. 1 Ex. 1
Ex. 2 Ex 3 Die - water mm 45 45 45 45 Temp. rollers 80 80 80 80
before oven #1, .degree. C. Stretching ratio 5.42 5.00 5.00 5.00
Temp oven 1, .degree. C. 95 95 95 95 Temp. rollers 110 110 110 110
before oven #2, .degree. C. Relaxation ratio 0.74 0.79 0.78 0.80
Temp. oven 2, .degree. C. 118 118 118 118 Temp rollers 100 100 100
100 before oven #3, .degree. C. Relaxation ratio 1.02 1.03 1.03
1.01 Temp. oven #3, .degree. C. 115 115 115 115 Temp rollers after
30 30 30 30 oven #3, .degree. C. Final speed m/min 130 130 130.5
130 Melt pump rpm 36.2 36.2 35 36.2 Tool pressure, bar 100.0 94.7
99.2 91.5 Melt Temperature 234.6 233.7 234.2 230.5 .degree. C.
Linear weight 1990 1992 2022 2002 (Titer)/dtex Stability, cN/dtex
1.06 1.15 1.13 1.02 Residual 79.2 86.7 82.1 70.6 Elongation, %
Shrink, % 4.9 3.6 3.8 4.2 Curl ratio 0.56 0.39 0.32 0.27
[0052] Each of the Inventive and Comparative Turf Yarn Examples.
Methods of forming artificial turf are known and disclosed, for
example, in PCT Publication 20110330, the disclosure of which is
incorporated herein by reference. The Turf Yarn Examples were
tested using the curl method for twist and curl. Inventive Turf
Yarn Example 3 showed the lowest twist and curl, corresponding to
the lowest residual stress in the yarn. Inventive Turf Yarn
Examples 1 and 2 also showed very low twist and curl in comparison
to Comparative Turf Yarn Example 1.
Composition Test Methods
[0053] Polymer composition test methods include the following:
Density
[0054] Samples for density measurement are prepared according to
ASTM D 1928. Measurements are made within one hour of sample
pressing using ASTM D792, Method B.
Melt Index
[0055] Melt index, or I.sub.2, is measured in accordance with ASTM
D 1238, Condition 190.degree. C./2.16 kg. I.sub.10 is measured in
accordance with ASTM D 1238, Condition 190.degree. C./10 kg.
Gel Permeation Chromatography (GPC)
[0056] The GPC system consists of a Waters (Milford, Mass.)
150.degree. C. high temperature chromatograph (other suitable high
temperatures GPC instruments include Polymer Laboratories
(Shropshire, UK) Model 210 and Model 220) equipped with an on-board
differential refractometer (RI). Additional detectors can include
an IR4 infra-red detector from Polymer ChAR (Valencia, Spain),
Precision Detectors (Amherst, Mass.) 2-angle laser light scattering
detector Model 2040, and a Viscotek (Houston, Tex.) 150R
4-capillary solution viscometer. A GPC with the last two
independent detectors and at least one of the first detectors is
sometimes referred to as "3D-GPC", while the term "GPC" alone
generally refers to conventional GPC. Depending on the sample,
either the 15-degree angle or the 90-degree angle of the light
scattering detector is used for calculation purposes. Data
collection is performed using Viscotek TriSEC software, Version 3,
and a 4-channel Viscotek Data Manager DM400. The system is also
equipped with an on-line solvent degassing device from Polymer
Laboratories (Shropshire, UK). Suitable high temperature GPC
columns can be used such as four 30 cm long Shodex HT803 13 micron
columns or four 30 cm Polymer Labs columns of 20-micron
mixed-pore-size packing (MixA LS, Polymer Labs). The sample
carousel compartment is operated at 140 .degree. C. and the column
compartment is operated at 150 .degree. C. The samples are prepared
at a concentration of 0.1 grams of polymer in 50 milliliters of
solvent. The chromatographic solvent and the sample preparation
solvent contain 200 ppm of butylated hydroxytoluene (BHT). Both
solvents are sparged with nitrogen. The polyethylene samples are
gently stirred at 160 .degree. C. for four hours. The injection
volume is 200 microliters. The flow rate through the GPC is set at
1 ml/minute.
[0057] The GPC column set is calibrated before running the Examples
by running twenty-one narrow molecular weight distribution
polystyrene standards. The molecular weight (MW) of the standards
ranges from 580 to 8,400,000 grams per mole, and the standards are
contained in 6 "cocktail" mixtures. Each standard mixture has at
least a decade of separation between individual molecular weights.
The standard mixtures are purchased from Polymer Laboratories
(Shropshire, UK). The polystyrene standards are prepared at 0.025 g
in 50 mL of solvent for molecular weights equal to or greater than
1,000,000 grams per mole and 0.05 g in 50 ml of solvent for
molecular weights less than 1,000,000 grams per mole. The
polystyrene standards were dissolved at 80 .degree. C. with gentle
agitation for 30 minutes. The narrow standards mixtures are run
first and in order of decreasing highest molecular weight component
to minimize degradation. The polystyrene standard peak molecular
weights are converted to polyethylene M.sub.w using the
Mark-Houwink K and a (sometimes referred to as .alpha.) values
mentioned later for polystyrene and polyethylene. See the Examples
section for a demonstration of this procedure.
[0058] With 3D-GPC, absolute weight average molecular weight
("M.sub.w,Abs") and intrinsic viscosity are also obtained
independently from suitable narrow polyethylene standards using the
same conditions mentioned previously. These narrow linear
polyethylene standards may be obtained from Polymer Laboratories
(Shropshire, UK; Part No.'s PL2650-0101 and PL2650-0102). The
systematic approach for the determination of multi-detector offsets
is performed in a manner consistent with that published by Balke,
Mourey, et al. (Mourey and Balke, Chromatography Polym., Chapter
12, (1992)) (Balke, Thitiratsakul, Lew, Cheung, Mourey,
Chromatography Polym., Chapter 13, (1992)), optimizing triple
detector log (M.sub.w and intrinsic viscosity) results from Dow
1683 broad polystyrene (American Polymer Standards Corp.; Mentor,
Ohio) or its equivalent to the narrow standard column calibration
results from the narrow polystyrene standards calibration curve.
The molecular weight data, accounting for detector volume off-set
determination, are obtained in a manner consistent with that
published by Zimm (Zimm, B. H., J. Chem. Phys., 16, 1099 (1948))
and Kratochvil (Kratochvil, P., Classical Light Scattering from
Polymer Solutions, Elsevier, Oxford, N.Y. (1987)). The overall
injected concentration used in the determination of the molecular
weight is obtained from the mass detector area and the mass
detector constant derived from a suitable linear polyethylene
homopolymer, or one of the polyethylene standards. The calculated
molecular weights are obtained using a light scattering constant
derived from one or more of the polyethylene standards mentioned
and a refractive index concentration coefficient, dn/dc, of 0.104.
Generally, the mass detector response and the light scattering
constant should be determined from a linear standard with a
molecular weight in excess of about 50,000 daltons. The viscometer
calibration can be accomplished using the methods described by the
manufacturer or alternatively by using the published values of
suitable linear standards such as Standard Reference Materials
(SRM) 1475a, 1482a, 1483, or 1484a. The chromatographic
concentrations are assumed low enough to eliminate addressing
2.sup.nd viral coefficient effects (concentration effects on
molecular weight).
Crystallization Elution Fractionation (CEF) Method
[0059] Comonomer distribution analysis is performed with
Crystallization Elution Fractionation (CEF) (PolymerChar in Spain)
(B Monrabal et al, Macromol. Symp. 257, 71-79 (2007)).
Ortho-dichlorobenzene (ODCB) with 600 ppm antioxidant butylated
hydroxytoluene (BHT) is used as solvent. Sample preparation is done
with autosampler at 160.degree. C. for 2 hours under shaking at 4
mg/ml (unless otherwise specified). The injection volume is 300
.mu.l. The temperature profile of CEF is: crystallization at
3.degree. C./min from 110.degree. C. to 30.degree. C., the thermal
equilibrium at 30.degree. C. for 5 minutes, elution at 3.degree.
C./min from 30.degree. C. to 140.degree. C. The flow rate during
crystallization is at 0.052 ml/min. The flow rate during elution is
at 0.50 ml/min. The data is collected at one data point/second. CEF
column is packed by The Dow Chemical Company with glass beads at
125 .mu.m.+-.6% (MO-SCI Specialty Products) with 1/8 inch stainless
tubing. Glass beads are acid washed by MO-SCI Specialty with the
request from The Dow Chemical Company. Column volume is 2.06 ml.
Column temperature calibration is performed by using a mixture of
NIST Standard Reference Material Linear polyethylene 1475a (1.0
mg/ml) and Eicosane (2 mg/ml) in ODCB. Temperature is calibrated by
adjusting elution heating rate so that NIST linear polyethylene
1475a has a peak temperature at 101.0.degree. C., and Eicosane has
a peak temperature of 30.0.degree. C. The CEF column resolution is
calculated with a mixture of NIST linear polyethylene 1475a (1.0
mg/ml) and hexacontane (Fluka, purum, .gtoreq.97.0%, 1 mg/ml). A
baseline separation of hexacontane and NIST polyethylene 1475a is
achieved. The area of hexacontane (from 35.0 to 67.0.degree. C.) to
the area of NIST 1475a from 67.0 to 110.0.degree. C. is 50 to 50,
the amount of soluble fraction below 35.0.degree. C. is <1.8 wt
%. The CEF column resolution is defined in the following
equation:
Resolution = Peak temperature of NIST 1475 a - Peak Temperature of
Hexacontane Half - height Width of NIST 1475 a + Half - height
Width of Hexacontane ##EQU00001##
where the column resolution is 6.0.
Comonomer Distribution Constant (CDC) Method
[0060] Comonomer distribution constant (CDC) is calculated from
comonomer distribution profile by CEF. CDC is defined as Comonomer
Distribution Index divided by Comonomer Distribution Shape Factor
multiplying by 100 as shown in the following equation:
CDC = Comonomer Distribution Index Comonomer Distribution Shape
Factor = Comonmer Distribution Index Half Width / Stdev * 100
##EQU00002##
[0061] Comonomer distribution index stands for the total weight
fraction of polymer chains with the comonomer content ranging from
0.5 of median comonomer content (C.sub.median) and 1.5 of
C.sub.median from 35.0 to 119.0.degree. C. Comonomer Distribution
Shape Factor is defined as a ratio of the half width of comonomer
distribution profile divided by the standard deviation of comonomer
distribution profile from the peak temperature (T.sub.p).
[0062] CDC is calculated from comonomer distribution profile by
CEF, and CDC is defined as Comonomer Distribution Index divided by
Comonomer Distribution Shape Factor multiplying by 100 as shown in
the following Equation:
CDC = Comonomer Distrubution Index Comonomer Distribution Shape
Factor = Comonomer Distribution Index Half Width / Stdev * 100
##EQU00003##
[0063] wherein Comonomer distribution index stands for the total
weight fraction of polymer chains with the comonomer content
ranging from 0.5 of median comonomer content (C.sub.median) and 1.5
of C.sub.median from 35.0 to 119.0.degree. C., and wherein
Comonomer Distribution Shape Factor is defined as a ratio of the
half width of comonomer distribution profile divided by the
standard deviation of comonomer distribution profile from the peak
temperature (Tp).
[0064] CDC is calculated according to the following steps:
[0065] (A) Obtain a weight fraction at each temperature (7)
(w.sub.T(T)) from 35.0.degree. C. to 119.0.degree. C. with a
temperature step increase of 0.200.degree. C. from CEF according to
the following Equation:
.intg. 35 119.0 w T ( T ) T = 1 ##EQU00004##
[0066] (B) Calculate the median temperature (T.sub.median) at
cumulative weight fraction of 0.500, according to the following
Equation:
.intg. 35 T median w T ( T ) T = 0.5 ##EQU00005##
[0067] (C) Calculate the corresponding median comonomer content in
mole % (C.sub.median) at the median temperature (T.sub.median) by
using comonomer content calibration curve according to the
following Equation:
ln ( 1 - comonomerc ontent ) = - 207.26 273.12 + T + 0.5533
##EQU00006## R 2 = 0.997 ##EQU00006.2##
[0068] (D) Construct a comonomer content calibration curve by using
a series of reference materials with known amount of comonomer
content, i.e., eleven reference materials with narrow comonomer
distribution (mono-modal comonomer distribution in CEF from 35.0 to
119.0.degree. C.) with weight average M.sub.w of 35,000 to 115,000
(measured via conventional GPC) at a comonomer content ranging from
0.0 mole % to 7.0 mole % are analyzed with CEF at the same
experimental conditions specified in CEF experimental sections;
[0069] (E) Calculate comonomer content calibration by using the
peak temperature (T.sub.p) of each reference material and its
comonomer content; The calibration is calculated from each
reference material according to the following Equation:
ln ( 1 - comonomerc ontent ) = - 207.26 273.12 + T + 0.5533
##EQU00007## R 2 = 0.997 ##EQU00007.2##
[0070] wherein: R.sup.2 is the correlation constant;
[0071] (F) Calculate Comonomer Distribution Index from the total
weight fraction with a comonomer content ranging from
0.5*C.sub.median to 1.5*C.sub.median, and if T.sub.median is higher
than 98.0.degree. C., Comonomer Distribution Index is defined as
0.95;
[0072] (G) Obtain Maximum peak height from CEF comonomer
distribution profile by searching each data point for the highest
peak from 35.0.degree. C. to 119.0.degree. C. (if the two peaks are
identical, then the lower temperature peak is selected); half width
is defined as the temperature difference between the front
temperature and the rear temperature at the half of the maximum
peak height, the front temperature at the half of the maximum peak
is searched forward from 35.0.degree. C., while the rear
temperature at the half of the maximum peak is searched backward
from 119.0.degree. C., in the case of a well defined bimodal
distribution where the difference in the peak temperatures is equal
to or greater than the 1.1 times of the sum of half width of each
peak, the half width of the inventive ethylene-based polymer
composition is calculated as the arithmetic average of the half
width of each peak; (H) Calculate the standard deviation of
temperature (Stdev) according the following Equation:
Stdev = 35.0 119.0 ( T - T p ) 2 * w T ( T ) ##EQU00008##
Creep Zero Shear Viscosity Measurement Method
[0073] Zero-shear viscosities are obtained via creep tests that
were conducted on an AR-G2 stress controlled rheometer (TA
Instruments; New Castle, Del.) using 25-mm-diameter parallel plates
at 190.degree. C. The rheometer oven is set to test temperature for
at least 30 minutes prior to zeroing fixtures. At the testing
temperature a compression molded sample disk is inserted between
the plates and allowed to come to equilibrium for 5 minutes. The
upper plate is then lowered down to 50 .mu.m above the desired
testing gap (1.5 mm). Any superfluous material is trimmed off and
the upper plate is lowered to the desired gap. Measurements are
done under nitrogen purging at a flow rate of 5 L/min. Default
creep time is set for 2 hours.
[0074] A constant low shear stress of 20 Pa is applied for all of
the samples to ensure that the steady state shear rate is low
enough to be in the Newtonian region. The resulting steady state
shear rates are in the range of 10.sup.-3 to 10.sup.-4 s.sup.-1 for
the samples in this study. Steady state is determined by taking a
linear regression for all the data in the last 10% time window of
the plot of log (J(t)) vs. log(t), where J(t) is creep compliance
and t is creep time. If the slope of the linear regression is
greater than 0.97, steady state is considered to be reached, then
the creep test is stopped. In all cases in this study the slope
meets the criterion within 2 hours. The steady state shear rate is
determined from the slope of the linear regression of all of the
data points in the last 10% time window of the plot of c vs. t,
where .epsilon. is strain. The zero-shear viscosity is determined
from the ratio of the applied stress to the steady state shear
rate.
[0075] In order to determine if the sample is degraded during the
creep test, a small amplitude oscillatory shear test is conducted
before and after the creep test on the same specimen from 0.1 to
100 rad/s. The complex viscosity values of the two tests are
compared. If the difference of the viscosity values at 0.1 rad/s is
greater than 5%, the sample is considered to have degraded during
the creep test, and the result is discarded.
[0076] Zero-Shear Viscosity Ratio (ZSVR) is defined as the ratio of
the zero-shear viscosity (ZSV) of the branched polyethylene
material to the ZSV of the linear polyethylene material at the
equivalent weight average molecular weight (Mw-gpc) according to
the following Equation:
ZSVR = .eta. 0 B .eta. 0 L = .eta. 0 B 2.29 .times. 10 - 15 M w -
gpc 3.65 ##EQU00009##
[0077] The ZSV value is obtained from creep test at 190.degree. C.
via the method described above. The Mw-gpc value is determined by
the conventional GPC method. The correlation between ZSV of linear
polyethylene and its Mw-gpc was established based on a series of
linear polyethylene reference materials. A description for the
ZSV-Mw relationship can be found in the ANTEC proceeding: Karjala,
Teresa P.; Sammler, Robert L.; Mangnus, Marc A.; Hazlitt, Lonnie
G.; Johnson, Mark S.; Hagen, Charles M., Jr.; Huang, Joe W. L.;
Reichek, Kenneth N. Detection of low levels of long-chain branching
in polyolefins. Annual Technical Conference--Society of Plastics
Engineers (2008), 66th 887-891.
.sup.1H NMR Method
[0078] 3.26 g of stock solution is added to 0.133 g of polyolefin
sample in 10 mm NMR tube. The stock solution is a mixture of
tetrachloroethane-d.sub.2 (TCE) and perchloroethylene (50:50, w:w)
with 0.001M Cr.sup.3+. The solution in the tube is purged with
N.sub.2 for 5 minutes to reduce the amount of oxygen. The capped
sample tube is left at room temperature overnight to swell the
polymer sample. The sample is dissolved at 110.degree. C. with
shaking The samples are free of the additives that may contribute
to unsaturation, e.g. slip agents such as erucamide.
[0079] The .sup.1H NMR are run with a 10 mm cryoprobe at
120.degree. C. on Bruker AVANCE 400 MHz spectrometer.
[0080] Two experiments are run to get the unsaturation: the control
and the double pre-saturation experiments.
[0081] For the control experiment, the data is processed with
exponential window function with LB=1 Hz, baseline was corrected
from 7 to -2 ppm. The signal from residual .sup.1H of TCE is set to
100, the integral I.sub.total from -0.5 to 3 ppm is used as the
signal from whole polymer in the control experiment. The number of
CH.sub.2 group, NCH.sub.2, in the polymer is calculated as
following:
NCH.sub.2=I.sub.total/2
[0082] For the double presaturation experiment, the data is
processed with exponential window function with LB=1 Hz, baseline
was corrected from 6.6 to 4.5 ppm. The signal from residual .sub.1H
of TCE is set to 100, the corresponding integrals for unsaturations
(I.sub.vinylene, I.sub.trisubstituted, I.sub.vinyl and
I.sub.vinylidene) were integrated based on the region shown in the
graph below
[0083] The number of unsaturation unit for vinylene,
trisubstituted, vinyl and vinylidene are calculated:
N.sub.vinylene=I.sub.vinylene/2
N.sub.trisubstituted=I.sub.trisubstitute
N.sub.vinyl=I.sub.vinyl/2
N.sub.vinylidene=I.sub.vinylidene/2
The unsaturation unit/1,000,000 carbons is calculated as
following:
N.sub.vinylene/1,000,000C=(N.sub.vinylene/NCH.sub.2)*1,000,000
N.sub.trisubstituted/1,000,000C=(N.sub.trisubstituted/NCH.sub.2)*1,000,0-
00
N.sub.vinyl/1,000,000C=(N.sub.vinyl/NCH.sub.2)*1,000,000
N.sub.vinylidene/1,000,000C=(N.sub.vinylidene/NCH.sub.2)*1,000,000
[0084] The requirement for unsaturation NMR analysis includes:
level of quantitation is 0.47.+-.0.02/1,000,000 carbons for Vd2
with 200 scans (less than 1 hour data acquisition including time to
run the control experiment) with 3.9 wt % of sample (for Vd2
structure, see Macromolecules, vol. 38, 6988, 2005), 10 mm high
temperature cryoprobe. The level of quantitation is defined as
signal to noise ratio of 10.
[0085] The chemical shift reference is set at 6.0 ppm for the
.sup.1H signal from residual proton from TCT-d2. The control is run
with ZG pulse, TD 32768, NS 4, DS 12, SWH 10,000 Hz, AQ 1.64 s, D1
14 s. The double presaturation experiment is run with a modified
pulse sequence, O1P 1.354 ppm, O2P 0.960 ppm, PL9 57 db, PL21 70
db, TD 32768, NS 200, DS 4, SWH 10,000 Hz, AQ 1.64 s, D1 1 s, D13
13 s. The modified pulse sequences for unsaturation with Bruker
AVANCE 400 MHz spectrometer are shown below:
TABLE-US-00007 ;lc1prf2_zz prosol relations=<lcnmr> #include
<Avance.incl> "d12=20u" "d11=4u" 1 ze d12 pl21:f2 2 30m d13
d12 pl9:f1 d1 cw:f1 ph29 cw:f2 ph29 d11 do:f1 do:f2 d12 pl1:f1 p1
ph1 go=2 ph31 30m mc #0 to 2 F0(zd) exit ph1=0 2 2 0 1 3 3 1 ph29=0
ph31=0 2 2 0 1 3 3 1
Turf Yarn Test Methods
[0086] The following test methods were used to measure various
properties of the turf yarns, prepared as described above on a
three oven process.
[0087] Linear Weight: The linear weight (in dtex) of a monofilament
is equal to the weight in grams of 50 meters of the monofilament
and extrapolating that measurements to obtain the weight of 10 km
of the monofilament.
[0088] Stability and Residual Elongation: Stability and residual
elongation were measured on a Zwick tensile tester on a filament
length of 260 mm and an extension rate of 250 mm/min until the
filament breaks. Stability is defined as the tensile force at break
divided by the linear weight (dtex). Residual elongation is the
strain at break.
[0089] Shrink: The shrink of a monofilament (expressed as the
percentage reduction in length of a 1 meter sample of the
monofilament) is measured by immersing the monofilament for 20
seconds in a bath of silicon oil maintained at 90.degree. C.
[0090] Curl: Curl is measured by taking yarn from the bobbin and
bending 2.times.8 filaments into a brush and fixing them by tape.
The brush is hung on a hook for 5 minutes at 90.degree. C. in a hot
air oven. Thereafter, a photograph is taken of the brush and the
spread of the fibers (10 in FIG. 1) at their tip is divided by the
length of the brush (20 in FIG. 1) to calculate the curl.
[0091] Unless otherwise stated, implicit from the context or
conventional in the art, all parts and percentages are based on
weight. All applications, publications, patents, test procedures,
and other documents cited, including priority documents, are fully
incorporated by reference to the extent such disclosure is not
inconsistent with the disclosed compositions and methods and for
all jurisdictions in which such incorporation is permitted.
[0092] The present invention may be embodied in other forms without
departing from the spirit and the essential attributes thereof,
and, accordingly, reference should be made to the appended claims,
rather than to the foregoing specification, as indicating the scope
of the invention.
* * * * *