U.S. patent application number 16/309007 was filed with the patent office on 2019-10-10 for artificial turf wtih improved tuft-lock.
This patent application is currently assigned to Dow Global Technologies LLC. The applicant listed for this patent is Dow Global Technologies LLC. Invention is credited to Barbara Bonavoglia, David Lopez, Ronald Wevers.
Application Number | 20190309487 16/309007 |
Document ID | / |
Family ID | 56372866 |
Filed Date | 2019-10-10 |
United States Patent
Application |
20190309487 |
Kind Code |
A1 |
Bonavoglia; Barbara ; et
al. |
October 10, 2019 |
ARTIFICIAL TURF WTIH IMPROVED TUFT-LOCK
Abstract
Embodiments of the present disclosure are directed to stretched
filaments comprising a non-functionalized polyolefin and at least
one functionalized polymer. The functionalized polymer is a
propylene-based plastomer or elastomer having one or more
functional groups grafted on the propylene-based plastomer or
elastomer. The one or more functional groups is selected from the
group consisting of amine groups and imide groups. The at least one
functionalized polymer has a DSC melting point from 100.degree. C.
to 130.degree. C. When the stretched filament is stretched to a
stretch ratio of 5, the stretched filament has a tenacity greater
than 0.90 cN/dtex
Inventors: |
Bonavoglia; Barbara;
(Zuerich, CH) ; Lopez; David; (Tarragona, ES)
; Wevers; Ronald; (s'Gravenpolder, NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dow Global Technologies LLC |
Midland |
MI |
US |
|
|
Assignee: |
Dow Global Technologies LLC
Midland
MI
|
Family ID: |
56372866 |
Appl. No.: |
16/309007 |
Filed: |
October 27, 2016 |
PCT Filed: |
October 27, 2016 |
PCT NO: |
PCT/US2016/059092 |
371 Date: |
December 11, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D06M 2101/32 20130101;
D01F 6/46 20130101; D06M 2101/20 20130101; D06M 11/09 20130101;
D06M 2101/34 20130101; E01C 13/08 20130101 |
International
Class: |
E01C 13/08 20060101
E01C013/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 30, 2016 |
EP |
16382313.1 |
Claims
1. A stretched filament formed from a blend comprising: at least
one functionalized polymer, wherein the functionalized polymer is a
propylene-based plastomer or elastomer having one or more
functional groups grafted on the propylene-based plastomer or
elastomer, wherein the one or more functional groups is selected
from the group consisting of amine groups and imide groups, wherein
the at least one functionalized polymer has a differential scanning
calorimetry (DSC) melting point of from 100.degree. C. to
130.degree. C.; and a non-functionalized polyolefin; wherein when
the stretched filament is stretched to a stretch ratio of 5, the
stretched filament has a tenacity greater than 0.90 cN/dtex.
2. The stretched filament of claim 1, wherein the
non-functionalized polyolefin comprises a polyethylene having a
density (measured according to ASTM D792) of from 0.900 g/cc to
0.950 g/cc and a melt index, I.sub.2, measured according to ASTM D
1238 (190.degree. C. and 2.16 kg), of from 0.1 g/10 min to 10 g/10
min.
3. The stretched filament of claim 1, wherein the
non-functionalized polyolefin comprises a polyethylene having a
density (measured according to ASTM D792) of from 0.915 g/cc to
0.940 g/cc and a melt index, I.sub.2, measured according to ASTM D
1238 (190.degree. C. and 2.16 kg), of from 0.7 g/10 min to 5 g/10
min.
4. The stretched filament of claim 2, wherein the polyethylene has
a melt flow ratio, I.sub.10/I.sub.2, of from 5 to 14, wherein
I.sub.10 is measured according to ASTM D1238 (190.degree. C. and 10
kg).
5. The stretched filament of claim 1, wherein the
non-functionalized polyolefin comprises a polypropylene
homopolymer.
6. The stretched filament of claim 5, wherein the
non-functionalized polyolefin has a melt flow rate (MFR.sub.2) of
0.5 g/10 min to 25 g/10 min.
7. The stretched filament of claim 5, wherein the polypropylene
homopolymer has a MFR.sub.2 of 0.5 g/10 min to 10 g/10 min.
8. The stretched filament of claim 1, wherein the functionalized
polymer has a graft level of from 0.1 wt. % to 3.0 wt. %.
9. The stretched filament of claim 1, wherein the propylene-based
plastomer or elastomer is a propylene/ethylene copolymer or a
propylene/alpha-olefin copolymer wherein the alpha-olefin is a
C.sub.4-C.sub.20 alpha-olefin.
10. The stretched filament of claim 1, wherein the at least one
functionalized polymer has a melt flow rate (MFR.sub.2) measured
according to ASTM D 1238 (230.degree. C. and 2.16 kg), of from 1
g/10 min to 20 g/10 min.
11. An artificial turf system comprising: a primary backing; a
secondary backing; and the stretched filament of claim 1.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to European Patent
Application No. 16382313.1, filed Jun. 30, 2016, which is
incorporated by reference herein in its entirety.
FIELD
[0002] Embodiments of the present disclosure generally relate to
stretched filaments, articles incorporating stretched filaments,
and their manufacture.
BACKGROUND
[0003] Synthetic or artificial turfs are increasingly being used as
an alternative to natural grass turf for use on sport athletic
fields, playgrounds, landscaping, and in other leisure
applications. To produce an artificial turf, turf yarns may be
extruded, and then tufted through a primary backing. A secondary
backing may be applied to "glue" the turf yarn to the primary
backing.
[0004] During the lifetime of the artificial turf, the yarn and
backing are subjected to continuous stresses. The durability of the
artificial turf depends in large part on the adhesion between the
yarn and the backing. For example, if the adhesion between the yarn
and the backing are poor, the yarn filaments are pulled off the
backing as a result of the stresses, which may leave areas of the
artificial turf without yarn.
[0005] Accordingly, alternative artificial turf yarns and/or
artificial turfs having improved adhesion between the yarn and the
backing are desired.
SUMMARY
[0006] Disclosed in embodiments herein are stretched filaments. The
stretched filaments comprise a blend of at least one functionalized
polymer and a non-functionalized polyolefin. The functionalized
polymer is a propylene-based plastomer or elastomer having one or
more functional groups grafted thereon and having a Differential
Scanning calorimetry (DSC) melting point from 100.degree. C. to
130.degree. C. The one or more functional groups are selected from
the group consisting of amine groups and imide groups. When the
stretched filament is stretched to a stretch ratio of 5, the
stretched filament has a tenacity greater than 0.90 cN/dtex.
Various embodiments described herein exhibit improved adhesion
between the stretched filament and the polyurethane backing, as
will be described in greater detail hereinbelow. Without being
bound by theory, it is believed that the functionalized polymer
enhances the polarity, thus increasing the adhesion of the filament
to the polyurethane backing.
[0007] Even further disclosed in embodiments herein are artificial
turfs. The artificial turfs comprise a primary backing, a secondary
backing, and at least one stretched filament. The stretched
filaments comprise a blend of at least one functionalized polymer
and a non-functionalized polyolefin. The functionalized polymer is
a propylene-based plastomer or elastomer having one or more
functional groups grafted thereon and having a DSC melting point
from 100.degree. C. to 130.degree. C. The one or more functional
groups are selected from the group consisting of amine groups and
imide groups. When the stretched filament is stretched to a stretch
ratio of 5, the stretched filament has a tenacity greater than 0.90
cN/dtex.
[0008] Additional features and advantages of the embodiments will
be set forth in the detailed description which follows, and in part
will be readily apparent to those skilled in the art from that
description or recognized by practicing the embodiments described
herein, including the detailed description which follows, the
claims, as well as the appended drawings.
[0009] It is to be understood that both the foregoing and the
following description describe various embodiments and are intended
to provide an overview or framework for understanding the nature
and character of the claimed subject matter. The accompanying
drawings are included to provide a further understanding of the
various embodiments, and are incorporated into and constitute a
part of this specification. The drawings illustrate the various
embodiments described herein, and together with the description
serve to explain the principles and operations of the claimed
subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1A pictorially depicts an exemplary monofilament
extrusion line that may be used to produce the stretched filaments
according to one or more embodiments shown and described
herein;
[0011] FIG. 1B pictorially depicts an exemplary Collins fiber
spinning line that may be used to produce the stretched filaments
according to one or more embodiments shown and described herein;
and
[0012] FIG. 2 pictorially depicts a cutaway view of an artificial
turf according to one or more embodiments shown and described
herein.
DETAILED DESCRIPTION
[0013] Reference will now be made in detail to embodiments of
stretched filaments and artificial turfs incorporating stretched
filaments, characteristics of which are illustrated in the
accompanying drawings. As used herein, "filament" refers to
monofilaments, multifilaments, extruded films, fibers, yarns, such
as, for example, tape yarns, fibrillated tape yarn, slit-film yarn,
continuous ribbon, and/or other fibrous materials used to form
synthetic grass blades or strands of an artificial turf field.
Stretched Filaments
[0014] The stretched filaments described herein are formed from a
blend comprising at least one functionalized polymer and a
non-functionalized polyolefin. The term "blend" means an intimate
physical mixture (that is, without reaction) of two or more
polymers. A blend may or may not be miscible (not phase separated
at molecular level). A blend may or may not be phase separated. A
blend may or may not contain one or more domain configurations, as
determined from transmission electron spectroscopy, light
scattering, x-ray scattering, and other methods known in the art.
The blend may be effected by physically mixing the two or more
polymers on the macro level (for example, melt blending resins or
compounding) or the micro level (for example, simultaneous forming
within the same reactor). As used herein, the term
"non-functionalized polyolefin" refers to a polyolefin that is free
of grafted moieties. Specifically, a "non-functionalized" ethylene
based polymer in this case is a resin only having ethylene and one
other comonomer (e.g., propylene, octene, hexene, butene, etc.) and
a polymer that does not go through a second step of
functionalization with another component. In various embodiments,
the functionalized polymer is a propylene-based plastomer or
elastomer having one or more functional groups grafted thereon. The
functional groups may be, for example, an amine group or an imide
group. The functionalized polymer has a DSC melting point from
100.degree. C. to 130.degree. C. When the stretched filament is
stretched to a stretch ratio of 5, the stretched filament has a
tenacity of greater than 0.9 cN/dtex.
Non Functionalized Polyolefin
[0015] The non-functionalized polyolefin may include, by way of
example and not limitation, non-functionalized polyethylene or
non-functionalized polypropylene. The term "polyethylene" refers to
a polymer that contains more than 50 weight percent polymerized
ethylene monomer (based on the total amount of polymerizable
monomers) and, optionally, may contain at least one comonomer. The
comonomer content may be measured using any suitable technique,
such as techniques based on nuclear magnetic resonance ("NMR")
spectroscopy, and, for example, by .sup.13C NMR analysis as
described in U.S. Pat. No. 7,498,282, which is incorporated herein
by reference.
[0016] Suitable polyethylenes may include ethylene homopolymers,
copolymers of ethylene and at least one comonomer, and blends
thereof. As used herein, the term "copolymer" includes polymers
made up of two or more different monomers, including trimers,
tetramers, and the like. In various embodiments, the polyethylene
comprises greater than or equal to 70 wt. % of the units derived
from ethylene and less than or equal to 30 wt. % of the units
derived from one or more alpha-olefin comonomers. In some
embodiments, the polyethylene comprises (a) greater than or equal
to 70%, greater than or equal to 75%, greater than or equal to 80%,
greater than or equal to 85%, greater than or equal to 90%, greater
than or equal to 92%, greater than or equal to 95%, greater than or
equal to 97%, greater than or equal to 98%, greater than or equal
to 99%, greater than or equal to 99.5%, from 70% to 99.5%, from 70%
to 99%, from 70% to 97% from 70% to 94%, from 80% to 99.5%, from
80% to 99%, from 80% to 97%, from 80% to 94%, from 80% to 90%, from
85% to 99.5%, from 85% to 99%, from 85% to 97%, from 88% to 99.9%,
88% to 99.7%, from 88% to 99.5%, from 88% to 99%, from 88% to 98%,
from 88% to 97%, from 88% to 95%, from 88% to 94%, from 90% to
99.9%, from 90% to 99.5% from 90% to 99%, from 90% to 97%, from 90%
to 95%, from 93% to 99.9%, from 93% to 99.5% from 93% to 99%, or
from 93% to 97%, by weight, of the units derived from the ethylene
monomer; and (b) optionally, less than or equal to 30%, for
example, less than 25%, or less than 20%, less than 18%, less than
15%, less than 12%, less than 10%, less than 8%, less than 5%, less
than 4%, less than 3%, less than 2%, less than 1%, from 0.1 to 20%,
from 0.1 to 15%, 0.1 to 12%, 0.1 to 10%, 0.1 to 8%, 0.1 to 5%, 0.1
to 3%, 0.1 to 2%, 0.5 to 12%, 0.5 to 10%, 0.5 to 8%, 0.5 to 5%, 0.5
to 3%, 0.5 to 2.5%, 1 to 10%, 1 to 8%, 1 to 5%, 1 to 3%, 2 to 10%,
2 to 8%, 2 to 5%, 3.5 to 12%, 3.5 to 10%, 3.5 to 8%, 3.5% to 7%, or
4 to 12%, 4 to 10%, 4 to 8%, or 4 to 7%, by weight, of units
derived from one or more alpha-olefin comonomers.
[0017] Suitable comonomers may include alpha-olefin comonomers,
typically having no more than 20 carbon atoms. The one or more
alpha-olefins may be selected from the group consisting of
C.sub.3-C.sub.20 acetylenically unsaturated monomers and
C.sub.4-C.sub.18 diolefins. Those skilled in the art will
understand that the selected monomers are desirably those that do
not destroy conventional Ziegler-Natta catalysts. For example, the
alpha-olefin comonomers may have 3 to 10 carbon atoms, or 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-1-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-butene, 1-hexene and 1-octene. In some embodiments,
the polyethylene comprises greater than 0 wt. % and less than 30
wt. % of units derived from one or more of octene, hexene, or
butene comonomers.
[0018] The polyethylene may be made according to any suitable
polymerization process, including but not limited to solution,
slurry, or gas phase polymerization processes in the presence of a
metallocene, constrained geometry catalyst systems, Ziegler-Natta
catalysts, or bisphenyl phenol catalyst systems. The solution,
slurry, or gas phase polymerization may occur in a single reactor,
or alternatively, in a dual reactor system wherein the same product
is produced in each of the dual reactors. Information on
preparation and use of the multi-metallic catalysts are found in
U.S. Pat. No. 9,255,160, the disclosure of which is incorporated
herein by reference in its entirety.
[0019] In embodiments herein, the polyethylene may be further
characterized by one or more of the following properties: melt
index (I.sub.2), melt flow ratio (I.sub.10/I.sub.2), or density, as
previously described herein. Without being bound by theory,
polyethylenes characterized by melt index (I.sub.2), melt flow
ratio (I.sub.10/I.sub.2), or density may be particularly well
suited for blending with other filament components and/or
extruding. For example, polymers with a melt index outside of a
particular range may present difficulties in obtaining a
homogeneous blend for extrusion.
[0020] Suitable polymers may include, for example, high density
polyethylene (HDPE), linear low density polyethylene (LLDPE),
ultra-low density polyethylene (ULDPE), homogeneously branched
linear ethylene polymers, and homogeneously branched substantially
linear ethylene polymers (that is, homogeneously branched long
chain branched ethylene polymers). In some embodiments, the
polyethylene is an LLDPE. The LLDPE may include, in polymerized
form, a majority weight percent of ethylene based on the total
weight of the LLDPE. In an embodiment, the LLDPE is a copolymer of
ethylene and at least one ethylenically unsaturated comonomer. In
one embodiment, the comonomer is a C.sub.3-C.sub.20 .alpha.-olefin.
In another embodiment, the comonomer is a C.sub.3-C.sub.8
.alpha.-olefin. In another embodiment, the C.sub.3-C.sub.8
.alpha.-olefin is selected from propylene, 1-butene, 1-hexene, or
1-octene. In an embodiment, the LLDPE is selected from the
following copolymers: ethylene/propylene copolymer, ethylene/butene
copolymer, ethylene/hexene copolymer, and ethylene/octene
copolymer. In a further embodiment, the LLDPE is an ethylene/octene
copolymer. Commercial examples of suitable ethylene-based
copolymers include those sold under the trade names ATTANE.TM.,
AFFINITY.TM., DOWLEX.TM., ELITE.TM., ELITE AT.TM., and INNATE.TM.
all available from The Dow Chemical Company (Midland, Mich.);
LUMICENE.RTM. available from Total SA; and EXCEED.TM. and EXACT.TM.
available from Exxon Chemical Company.
[0021] In embodiments herein, the polyethylene may have a density
of 0.900 g/cc to 0.950 g/cc. All individual values and subranges of
at least 0.900 g/cc to 0.950 g/cc are included and disclosed
herein. For example, in some embodiments, the polyethylene has a
density of 0.900 to 0.945 g/cc, 0.900 to 0.940 g/cc, 0.900 to 0.935
g/cc, 0.910 g/cc to 0.945 g/cc, 0.910 to 0.940 g/cc, 0.910 to 0.935
g/cc, 0.910 to 0.930 g/cc, 0.915 to 0.940 g/cc, 0.915 to 0.923
g/cc, or 0.920 g/cc to 0.935 g/cc. Density may be measured in
accordance with ASTM D792.
[0022] In embodiments herein, the polyethylene may have a melt
index, I.sub.2, measured in accordance with ASTM D1238 at
190.degree. C. and 2.16 kg of 0.1 g/10 min to 10 g/10 min. All
individual values and subranges of at least 0.1 g/10 min to 10 g/10
min are included and disclosed herein. For example, in some
embodiments, the polyethylene may have a melt index, I.sub.2, of
0.1 g/10 min to 9.5 g/10 min, 0.1 g/10 min to 9.0 g/10 min, 0.1
g/10 min to 5 g/10 min, 0.5 g/10 min to 6 g/10 min, 1 g/10 min to 5
g/10 min, 1.5 g/10 min to 4.5 g/10 min, or 2 g/10 min to 4 g/10
min. In other embodiments, the polyethylene may have a melt index,
I.sub.2, of 0.7 g/10 min to 9.5 g/10 min, 0.7 g/10 min to 8 g/10
min, or 0.7 g/10 min to 5 g/10 min. Melt index, I.sub.2, may be
measured in accordance with ASTM D1238 (190.degree. C. and 2.16
kg).
[0023] In embodiments herein, the polyethylene may have a melt flow
ratio, I.sub.10/I.sub.2, of less than 14. All individual values and
subranges of less than 14 are included and disclosed herein. For
example, in some embodiments, the polyethylene may have a melt flow
ratio, I.sub.10/I.sub.2, of less than 13.5, 13, 12.5, 10, or even
7.5. In other embodiments, the polyethylene may have a melt flow
ratio, I.sub.10/I.sub.2, of from 1.0 to 14, 2 to 14, 4 to 14, 5 to
14, 5.5 to 14, 6 to 14, 5 to 13.5, 5 to 13, 5 to 12.5, 5 to 12, 5
to 11.5, 5 to 11, 5.5 to 13.5, 5.5 to 13, 5.5 to 12.5, 5.5 to 12,
5.5 to 11.5, 5.5 to 11, 6 to 13.5, 6 to 13, 6 to 12.5, 6 to 12, 6
to 11.5, or 6 to 11. Melt index, I.sub.10, may be measured in
accordance with ASTM D1238 (190.degree. C. and 10.0 kg).
[0024] In other embodiments, the non-functionalized polyolefin
includes polypropylene. The term "polypropylene" refers to a
polymer that contains more than 50 weight percent polymerized
propylene monomer (based on the total amount of polymerizable
monomers) and, optionally, may contain at least one comonomer.
Suitable polypropylenes may include propylene homopolymers,
copolymers of propylene and at least one comonomer, and blends
thereof. In embodiments herein, the polypropylene may be a
propylene homopolymer, a propylene copolymer, or a combination
thereof. The polypropylene homopolymer may be isotactic, atactic,
or syndiotactic. In some embodiments, the polypropylene is an
isotactic polypropylene homopolymer. In other embodiments, the
polypropylene is a propylene/alpha-olefin copolymer. The
propylene/alpha-olefin copolymer may be random or block, or an
impact polypropylene copolymer. Impact polypropylene copolymers may
also include heterophasic polypropylene copolymers, where
polypropylene is the continuous phase and an elastomeric phase is
uniformly dispersed therein.
[0025] In various embodiments, the polypropylene comprises greater
than 50 wt. % of the units derived from propylene and less than 30
wt. % of the units derived from one or more C.sub.2 or C.sub.4-20
alpha-olefin comonomers. In some embodiments, the polypropylene
comprises (a) greater than or equal to 55%, for example, greater
than or equal to 60%, greater than or equal to 65%, greater than or
equal to 70%, greater than or equal to 75%, greater than or equal
to 80%, greater than or equal to 85%, greater than or equal to 90%,
greater than or equal to 92%, greater than or equal to 95%, greater
than or equal to 97%, greater than or equal to 98%, greater than or
equal to 99%, greater than or equal to 99.5%, from greater than 50%
to 99%, from greater than 50% to 97%, from greater than 50% to 94%,
from greater than 50% to 90%, from 70% to 99.5%, from 70% to 99%,
from 70% to 97% from 70% to 94%, from 80% to 99.5%, from 80% to
99%, from 80% to 97%, from 80% to 94%, from 80% to 90%, from 85% to
99.5%, from 85% to 99%, from 85% to 97%, from 88% to 99.9%, 88% to
99.7%, from 88% to 99.5%, from 88% to 99%, from 88% to 98%, from
88% to 97%, from 88% to 95%, from 88% to 94%, from 90% to 99.9%,
from 90% to 99.5% from 90% to 99%, from 90% to 97%, from 90% to
95%, from 93% to 99.9%, from 93% to 99.5% from 93% to 99%, or from
93% to 97%, by weight, of the units derived from propylene; and (b)
optionally, less than 30 percent, for example, less than 25
percent, or less than 20 percent, less than 18%, less than 15%,
less than 12%, less than 10%, less than 8%, less than 5%, less than
4%, less than 3%, less than 2%, less than 1%, from 0.1 to 20%, from
0.1 to 15%, 0.1 to 12%, 0.1 to 10%, 0.1 to 8%, 0.1 to 5%, 0.1 to
3%, 0.1 to 2%, 0.5 to 12%, 0.5 to 10%, 0.5 to 8%, 0.5 to 5%, 0.5 to
3%, 0.5 to 2.5%, 1 to 10%, 1 to 8%, 1 to 5%, 1 to 3%, 2 to 10%, 2
to 8%, 2 to 5%, 3.5 to 12%, 3.5 to 10%, 3.5 to 8%, 3.5% to 7%, or 4
to 12%, 4 to 10%, 4 to 8%, or 4 to 7%, by weight, of units derived
from one or more C.sub.2 or C.sub.4-20 alpha-olefin comonomers.
[0026] Suitable comonomers may include C.sub.2 or C.sub.4-20
alpha-olefin comonomers. The one or more alpha-olefin comonomers
may have 2 carbon atoms or 4 to 20 carbon atoms, C.sub.2 or
C.sub.4-18, C.sub.2 or C.sub.4-10, or C.sub.2 or 4 to 8 carbon
atoms. Exemplary alpha-olefin comonomers include, but are not
limited to, ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene,
1-octene, 1-nonene, 1-decene, and 4-methyl-1-pentene. The one or
more alpha-olefin comonomers may, for example, be selected from the
group consisting of ethylene, 1-butene, 1-hexene, and 1-octene. In
some embodiments, the polypropylene comprises greater than 0 wt. %
and less than 30 wt. % of units derived from one or more of octene,
hexene, butene, or ethylene comonomers.
[0027] The polypropylene can be made using any method for
polymerizing propylene and, optionally, one comonomer. For example,
gas phase, bulk or slurry phase, solution polymerization or any
combination thereof can be used. Polymerization can be a one stage
or a two or multistage polymerization process, carried out in at
least one polymerization reactor. For two or multistage processes
different combinations can be used, e.g. gas-gas phase,
slurry-slurry phase, slurry-gas phase processes. Suitable catalysts
can include Ziegler-Natta catalysts, a single-site catalyst
(metallocene or constrained geometry), or non-metallocene,
metal-centered, heteroaryl ligand catalysts, or combinations
thereof. Exemplary polypropylene polymers may include metallocene
polypropylenes, such as, ACHIEVE.TM. 3584, available from the
ExxonMobil Chemical Company, and LUMICENE.TM. MR 2001, available
from Total Research & Technology Feluy; and Ziegler-Natta
polypropylenes, such as, HG475FB, available from Borealis AG,
MOPLEN.TM. HP2814, available from Lyondell Basell Industries
Holdings, B.V., Sabic 518A, available from Saudi Basic Industries
Corporation.
[0028] In embodiments herein, the polypropylene may be further
characterized by one or more of the following properties: melt flow
rate (MFR.sub.2), melt flow ratio (MFR.sub.10/MFR.sub.2), or
density, as described herein.
[0029] In embodiments herein, the propylene based polymer may have
a density of from about 0.890 g/cc to about 0.910 g/cc. All
individual values and subranges of at least 0.890 g/cc to 0.910
g/cc are included and disclosed herein. For example, in some
embodiments, the polyethylene has a density of 0.890 to 0.905 g/cc,
0.890 to 0.900 g/cc, 0.890 to 0.895 g/cc, 0.895 g/cc to 0.910 g/cc,
0.900 to 0.910 g/cc, or 0.905 to 0.910 g/cc. Density may be
measured in accordance with ASTM D792.
[0030] In embodiments herein, the polypropylene may have a melt
flow rate, MFR.sub.2, of 0.5 g/10 min to 25 g/10 min when measured
according to ASTM D1238 at 230.degree. C. and 2.16 kg. All
individual values and subranges of at least 0.5 g/10 min to 25 g/10
min are included and disclosed herein. For example, in some
embodiments, the polypropylene may have a melt flow rate,
MFR.sub.2, of 0.5 g/10 min to 22.5 g/10 min, 0.5 g/10 min to 20
g/10 min, 0.5 g/10 min to 15 g/10 min, 0.5 g/10 min to 10 g/10 min,
1 g/10 min to 10 g/10 min, 1.5 g/10 min to 10 g/10 min, or 3 g/10
min to 10 g/10 min. In one embodiment, the polypropylene may have a
melt flow rate, MFR.sub.2, of 2.0 g/10 min to 4.0 g/10 min when
measured at 230.degree. C. and 2.16 kg. Melt flow rate, MFR.sub.2,
may be measured in accordance with ASTM D 1238 (230.degree. C. and
2.16 kg).
[0031] In embodiments herein, the polypropylene may have a melt
flow ratio, MFR.sub.10/MFR.sub.2, of less than 10. All individual
values and subranges of less than 10 are included and disclosed
herein. For example, in some embodiments, the polypropylene may
have a melt flow ratio, MFR.sub.10/MFR.sub.2, of less than 10, 9,
or even 7. In other embodiments, the polypropylene may have a melt
flow ratio, MFR.sub.10/MFR.sub.2, of from 1.0 to 10, 2 to 9, or 3
to 7. Melt flow rate, MFR.sub.10, may be measured in accordance
with ASTM D 1238 (230.degree. C. and 10.0 kg).
Functionalized Polymer
[0032] As stated above, the stretched filaments described herein
further include at least one functionalized polymer. In various
embodiments, the functionalized polymer has a propylene-based
plastomer or elastomer as its base polymer, and is herein referred
to as a propylene-based plastomer or elastomer, and has one or more
functional groups grafted thereon. In one embodiment, the at least
one functionalized polymer is a polymer formed from a
propylene-based plastomer or elastomer having at least one organic
compound selected from an "amine-containing compound" or an
"imide-containing compound" grafted thereon. As used herein, the
term "amine-containing compound" refers to a chemical compound
comprising at least one amine group. As used herein, the term
"imide-containing compound" refers to a chemical compound
comprising at least one imide group.
[0033] In embodiments described herein, the propylene-based
plastomer or elastomer is a propylene/ethylene copolymer or a
propylene/C.sub.4-C.sub.20 alpha-olefin copolymer. In one
embodiment, the propylene-based plastomer or elastomer is a
propylene/ethylene copolymer. In another embodiment, the
propylene-based plastomer or elastomer is a
propylene/C.sub.4-C.sub.20 alpha-olefin copolymer, or a
C.sub.4-C.sub.10 alpha-olefin, or a C.sub.4-C.sub.8 alpha-olefin.
In another embodiment, the alpha-olefin is selected from the group
consisting of ethylene, 1-butene, 1-hexene, and 1-octene. The
propylene-based plastomer or elastomer comprises at least 60 wt. %
of the units derived from propylene and between 1 and 40 wt. % of
the units derived from ethylene (based on the total amount of
polymerizable monomers). All individual values and subranges of at
least 60 wt. % of the units derived from propylene and between 1
and 40 wt. % of the units derived from ethylene are included and
disclosed herein. For example, the propylene-based plastomer or
elastomer based polymer can include greater than or equal to 60%,
greater than or equal to 65%, greater than or equal to 70%, greater
than or equal to 75%, greater than or equal to 80%, greater than or
equal to 85%, greater than or equal to 90%, greater than or equal
to 92%, greater than or equal to 95%, greater than or equal to 97%,
greater than or equal to 98%, greater than or equal to 99%, greater
than or equal to 99.5%, from greater than 60% to 99%, from greater
than 60% to 97%, from greater than 60% to 94%, from greater than
60% to 90%, from 70% to 99.5%, from 70% to 99%, from 70% to 97%
from 70% to 94%, from 80% to 99.5%, from 80% to 99%, from 80% to
97%, from 80% to 94%, from 80% to 90%, from 85% to 99.5%, from 85%
to 99%, from 85% to 97%, from 88% to 99.9%, 88% to 99.7%, from 88%
to 99.5%, from 88% to 99%, from 88% to 98%, from 88% to 97%, from
88% to 95%, from 88% to 94%, from 90% to 99%, from 90% to 99% from
90% to 99%, from 90% to 97%, from 90% to 95%, from 93% to 99%, from
93% to 99% from 93% to 99%, or from 93% to 97%, by weight, of the
units derived from propylene; and (b) optionally, less than 40
percent, for example, less than 40%, less than 35%, less than 30%,
less than 25%, or less than 20%, less than 18%, less than 15%, less
than 12%, less than 10%, less than 8%, less than 5%, less than 4%,
less than 3%, less than 2%, from 1 to 20%, from 1 to 15%, 1 to 12%,
1 to 10%, 1 to 8%, 1 to 5%, 1 to 3%, 1 to 2%, 2 to 10%, 2 to 8%, 2
to 5%, 3.5 to 12%, 3.5 to 10%, 3.5 to 8%, 3.5% to 7%, or 4 to 12%,
4 to 10%, 4 to 8%, or 4 to 7%, by weight, of units derived from
ethylene.
[0034] The functionalized propylene-based elastomer or plastomer
has a density from 0.850 g/cc to 0.930 g/cc. In another embodiment,
the propylene/alpha-olefin copolymer has a density from 0.870 g/cc
to 0.930 g/cc. In another embodiment, the propylene/alpha-olefin
copolymer has a melt flow rate, MFR.sub.2, measured at 230.degree.
C. and 2.16 kg, from 1 g/10 min to 20 g/10 min.
[0035] In another embodiment, the functionalized propylene-based
elastomer or plastomer is a propylene/ethylene copolymer. In a
further embodiment, the propylene/ethylene copolymer has a density
from 0.850 g/cc to 0.930 g/cc, or from 0.870 g/cc to 0.930 g/cc. In
another embodiment, the propylene/ethylene copolymer has a melt
flow rate (MFR.sub.2), measured in accordance with ASTM D1238 at
230.degree. C. and 2.16 kg, from 1 g/10 min to 20 g/10 min. In
embodiments herein, the propylene/ethylene copolymer has an
ethylene content of less than about 5 wt. %. In another embodiment,
the propylene/ethylene copolymer has an ethylene content of less
than about 4 wt. %. For example, the propylene/ethylene copolymer
may have an ethylene content of greater than about 0 wt. % to about
5 wt. %, including all individual values and subranges from greater
than about 0 wt. % to about 5 wt. %. In embodiments, the
propylene/ethylene compolymer has an ethylene content of from 0.001
wt. % to 5 wt. %, from 0.01 wt. % to 5 wt. %, from 0.1 wt. % to 5
wt. %, from 0.001 wt. % to 4 wt. %, from 0.01 wt. % to 4 wt. %,
from 0.1 wt. % to 4 wt. %, from 0.1 wt. % to 3.5 wt. %, from 0.1
wt. % to 3 wt. %, from 0.1 wt. % to 2.5 wt. %, or the like, Various
methodologies may be used to determine ethylene content, including
but not limited to, mass balance calculations and FTIR.
[0036] In various embodiments, the at least one functionalized
propylene-based plastomer or elastomer has a differential scanning
calorimetry (DSC) melting point from about 100.degree. C. to about
130.degree. C. or from about 110.degree. C. to about 120.degree. C.
The functionalized propylene-based plastomer or elastomer of
various embodiments has a percent crystallinity of less than or
equal to 30%, or less than or equal to 25%, or less than or equal
to 22.5%, as measured by DSC. In some embodiments, the
functionalized propylene-based plastomer or elastomer has a percent
crystallinity of from about 10% to about 30%, as measured by DSC,
including all individual values and subranges from 10% to 30%.
Suitable propylene-based plastomer or elastomers that may be
functionalized may include, by way of example and not limitation,
VERSIFY.TM. 3000, commercially available from The Dow Chemical
Company (Midland, Mich.).
Methods of Making Functionalized Polymers
[0037] In various embodiments, the at least one functionalized
polymer is formed by grafting an "amine-reactive" group onto a
propylene-based plastomer or elastomer to form a grafted
propylene-based plastomer or elastomer and then reacting the
grafted propylene-based plastomer or elastomer with an
"amine-containing compound" or "imide-containing compound."
[0038] For example, in an embodiment, the at least one
functionalized polymer is formed from a process comprising the
following steps: 1) grafting onto the backbone of a propylene-based
plastomer or elastomer at least one compound comprising at least
one "amine-reactive" group to form a grafted propylene-based
plastomer or elastomer; 2) reacting a primary-secondary diamine
with the grafted propylene-based plastomer or elastomer; and 3)
wherein step 2) takes place subsequent to step 1), without the
isolation of the grafted propylene-based plastomer or elastomer
(i.e., removal of the grafted propylene-based plastomer or
elastomer from the solution containing the compound containing the
amine-reactive group and the propylene-based plastomer or
elastomer), and wherein both steps take place in a melt reaction.
The term "amine-reactive group," as used, refers to a chemical
group or chemical moiety that can react with an amine group.
Amine-reactive groups include, but are not limited to, maleic
anhydride, acrylic acid, methacrylic acid, glycidyl acrylate,
glycidyl methacrylate.
[0039] As used herein, the term "primary-secondary diamine" refers
to a diamine made up of a primary amine and a secondary amine.
Suitable primary-secondary diamines include compounds of structure
(I):
H.sub.2N--R.sub.1--NH--R.sub.2 (I).
[0040] In structure (I), R.sub.1 is a divalent hydrocarbon radical,
and preferably a linear hydrocarbon of the formula
--(CH.sub.2).sub.n--, where n is greater than, or equal to, 2, n is
from 2 to 10, from 2 to 8, or even from 2 to 6. R.sub.2 is a
monovalent hydrocarbon radical containing at least 2 carbon atoms,
and optionally may be substituted with a heteroatom containing
group, such as OH or SH. In embodiments, R.sub.2 a linear
hydrocarbon of the formula --(CH.sub.2).sub.nCH.sub.3, where n is
from 1 to 10, from 1 to 9, from 1 to 7, or even from 1 to 5. In
embodiments, the primary-secondary diamine is selected from the
group consisting N-ethylethylenediamine, N-phenylethylenediamine,
N-phenyl-1,2-phenylene-diamine, N-phenyl-1,4-phenylenediamine, and
N-(2-hydroxyethyl)-ethylenediamine.
[0041] In another embodiment, the at least one functionalized
propylene-based plastomer or elastomer comprises the following
functional group covalently bonded to the propylene-based plastomer
or elastomer backbone:
##STR00001##
wherein "NR.sub.1NHR.sub.2" may be derived from a primary-secondary
diamine selected from the group of compounds of structure (I)
below:
H.sub.2N--R.sub.1--NH--R.sub.2 (I),
wherein R.sub.1 is a divalent hydrocarbon radical selected from the
group consisting of alkylene or phenylene, such as, by way of
example and not limitation, --CH.sub.2CH.sub.2--, -para-phenylene-,
or ortho-phenylene-, and R.sub.2 is a monovalent hydrocarbon
radical containing at least 2 carbon atoms, and optionally may be
substituted with a heteroatom containing group, such as an alkyl or
aryl group. In embodiments, the alkyl or aryl group is an ethyl or
a phenyl group.
[0042] In another embodiment, the at least one functionalized
polymer is formed from a process comprising the following steps: 1)
functionalizing the propylene-based plastomer or elastomer with at
least one compound comprising at least one "amine-reactive" group
to form a grafted propylene-based plastomer or elastomer; 2)
blending the grafted propylene-based plastomer or elastomer, in a
solid, non-molten form, with at least one primary-secondary
diamine; 3) imbibing the primary-secondary diamine into the grafted
propylene-based plastomer or elastomer; 4) reacting the
primary-secondary diamine with the grafted propylene-based
plastomer or elastomer to form an imide functionalized
propylene-based plastomer or elastomer. The term "imbibing," and
similar terms, as used, refers to the process in which a compound
is absorbed into a polymer solid, particle, pellet, or article.
More particularly, a polyolefin is first functionalized with a
group reactive with amine functionality, such as an anhydride
group. At least one diamine is mixed with the functionalized
polyolefin at a temperature below the melting point of the
polyolefin. In some embodiments, the temperature is room
temperature, although other temperatures are contemplated. The
diamine is allowed to absorb or imbibe into the polyolefin, and
reacts with diamine reactive group to form a succinamic acid. The
reaction of the diamine with the diamine reactive functional group
to form the imide ring can then be completed by subjecting the
mixture to a thermal treatment, such as in a melt extrusion
process. The imbibing process helps to ensure that the diamine is
thoroughly mixed with the polyolefin for an efficient
functionalization reaction.
[0043] In another embodiment, the at least one functionalized
polymer is formed from a process comprising the following steps: 1)
grafting onto the backbone of a propylene-based plastomer or
elastomer at least one compound comprising at least one
"amine-reactive" group to form a grafted propylene-based plastomer
or elastomer; 2) reacting a alkanolamine with the grafted
propylene-based plastomer or elastomer; and wherein step 2) takes
place subsequent to step 1), without the isolation of the grafted
propylene-based plastomer or elastomer, and wherein both steps 1)
and 2) take place in a melt reaction.
[0044] In further embodiments, the alkanolamine is selected from
the group consisting of 2-aminoethanol, 2-amino-1-propanol,
3-amino-1-propanol, 2-amino-1-butanol, 2-(2-aminoethoxy)-ethanol
and 2-aminobenzyl alcohol.
[0045] Without being bound by theory, increased grafting on the
polypropylene increases the melt flow rate, I.sub.2, measured at
230.degree. C. and 2.16 kg, of the polymer. Accordingly, in order
to maintain a viscosity that is compatible with the viscosity of
the non-functionalized polyolefin, in various embodiments, the
propylene-based plastomer or elastomer has a graft level of from
about 0.1 wt. % to about 3.0 wt. %, depending on the particular
polypropylene-based elastomer or plastomer employed. The graft
level may be determined by Fourier Transform Infrared Spectroscopy
(FTIR). Without being bound by theory, compatibility of the melt
indices of the propylene-based plastomer or elastomer and the
non-functionalized polyolefin enables the components of the
stretched filaments to be suitably blended for extrusion.
[0046] In various embodiments, the stretched filaments include from
about 1 wt. % to about 30 wt. % of the functionalized polymer,
including all individual values and subranges from 1 wt. % to 30
wt. %. Such individual values and subranges are disclosed herein.
In another embodiment, the stretched filaments include from about 1
wt. % to about 20 wt. % of the functionalized polymer. In yet
another embodiment, the stretched filaments include from about 5
wt. % to about 20 wt. % of the functionalized polymer. In
embodiments described herein, the stretched filaments include from
about 68 wt. % to about 99 wt. % of the non-functionalized
polyolefin, including all individual values and subranges from 68
wt. % to 99 wt. %. In other embodiments, the stretched filaments
include from about 75 wt. % to about 99 wt. % of the
non-functionalized polyolefin, from about 80 wt. % to about 99 wt.
% of the non-functionalized polyolefin, or even from about 85 wt. %
to about 99 wt. % of the non-functionalized polyolefin.
[0047] In embodiments herein, the stretched filaments may further
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. In an embodiment,
colorant, such as SICOLEN.TM. green 85-125345 (available from
BASF), may be added in an amount of less than about 10 wt. %, less
than about 8 wt. %, less than about 6 wt. %, or even less than
about 4 wt. %. In another embodiment, a processing aid, such as
ARX-741 (available from Argus), may be added in an amount of less
than about 2 wt. %, less than about 1.5 wt. %, or even less than
about 1 wt. %. Additives can be used in amounts ranging from about
0.001 wt. % to more than about 10 wt. % based on the weight of the
composition.
[0048] In various embodiments, when the stretched filament is
stretched to a stretch ratio of 5, the stretched filament has a
tenacity greater than 0.90 cN/dtex or from about 0.9 cN/dtex to
about 1.5 cN/dtex. The filament is stretched after the filament has
been formed using an extrusion process, but may be stretched using
an inline process where a stretching unit is connected with an
extrusion unit used to make the filament that forms the stretched
filament. However, the filament may also be stretched in a process
unconnected with the extrusion process. Tenacity is defined as the
tensile force at break divided by the linear weight (dtex). The
linear weight (in dtex) of a monofilament is equal to the weight of
weighing 50 meters of the monofilament. In embodiments, the
stretched filament may exhibit an elongation of at least 55% or at
least 60%. In embodiments, the stretched filament may exhibit an
elongation of from about 30% to about 150%, from about 90% to about
110%, or from about 95% to about 105%. Elongation, which is the
strain at break, is measured according to ISO 188/ASTM E145 on a
Zwick tensile tester on a filament length of 250 mm and extension
rate of 250 mm/minute until the filament breaks. In embodiments,
the tenacity and elongation values may impact the durability of the
filaments and, thus, the artificial turf made therefrom.
[0049] In some embodiments herein, the stretched filaments may
exhibit a shrinkage of less than 20%. Because the stretched
filaments exhibit low shrinkage, shorter filaments may be used to
maintain the final desired yarn length of the stretched. All
individual values and subranges of less than 20% are included and
disclosed herein. For example, in some embodiments, the stretched
filaments may exhibit a shrinkage lower than 19%, lower than 18%,
lower than 15% or lower than 14%. The shrinkage may be determined
by submerging 1 meter of yarn in a heated oil bath at 90.degree. C.
for 20 seconds.
Process for Making Stretched Filaments
[0050] The stretched filaments described herein may be made using
any appropriate process for the production of stretched filament
from polymer compositions as the stretched filaments described
herein are process independent. In some embodiments, a method of
manufacturing a stretched filament comprises providing a blend of a
non-functionalized polyolefin and a functionalized propylene-based
plastomer or elastomer as previously described herein, and
extruding the blend of the non-functionalized polyolefin and the
functionalized propylene-based plastomer or elastomer into a
stretched filament. The stretched filament may be extruded to a
specified width, thickness, and/or cross-sectional shape depending
on the physical dimensions of the extruder. As mentioned above, the
stretched filament can include a monofilament, a multifilament, a
film, a fiber, a yarn, such as, for example, tape yarn, fibrillated
tape yarn, or slit-film yarn, a continuous ribbon, and/or other
fibrous materials used to form synthetic grass blades or strands of
an artificial turf field.
[0051] Referring to FIGS. 1A and 1B, the following describes one
such exemplary process 100 that may be used to make stretched
filaments. In process 100, stretched filaments are made by
extrusion. For example, the non-functionalized polyolefin and the
functionalized propylene-based plastomer or elastomer may be
blended together along with any additives to form an extrusion
mixture. Suitable stretched filament extruders may be equipped with
a single polyethylene/polypropylene general purpose screw and a
melt pump ("gear pump" or "melt pump") to precisely control the
consistency of polymer volume flow into the die 105, as shown in
FIGS. 1A and 1B. Stretched filament dies 105 may have multiple
single holes for the individual filaments distributed over a
circular or rectangular spinplate. The shape of the holes
corresponds to the desired filament cross-section profile,
including for example, rectangular, dog-bone, and v-shaped. A
standard spinplate has 50 to 160 die holes of specific dimensions.
Lines can have output rates from 150 kg/h to 350 kg/h.
[0052] The stretched filaments 110 may be extruded into a water
bath 115 with a die-to-water bath distance of from 16 to 40 mm.
Coated guiding bars in the water redirect the filaments 110 towards
the first takeoff set of rollers 120. The linear speed of this
first takeoff set of rollers 120 may vary from 15 to 70 m/min. The
first takeoff set of rollers 120 can be heated and used to preheat
the filaments 110 after the waterbath 115 and before entering the
stretching oven 125. The stretching oven 125 may be a heated air or
water bath oven. The filaments 110 may be stretched in the
stretching oven 125 to a predetermined stretched ratio. In some
equipment configurations, the stretching oven 125 is replaced by
one or more heated godets 300-310, as shown in FIG. 1B. In some
embodiments, the stretch ratio is at least 4. In other embodiments,
the stretch ratio is at least 4.5, 4.8, 5.0, 5.2, or 5.5. The
stretching ratio is the ratio between the speed of the second
takeoff set of rollers 130 after the stretching oven and the speed
of the first takeoff set of rollers 120 before the stretching oven
(V2/V1 as shown in FIG. 1A). The second takeoff set of rollers 120
may be run at a different (higher or lower) speed than the first
set of rollers 130. In embodiments in which stretching is performed
over heated godets, the stretching ratio is the ratio between the
speed of the godet 310 and the speed of the godet 300.
[0053] After the filaments 110 are passed over the second takeoff
set of rollers 130, they are then drawn through a set of three
annealing ovens 135, 140, and 145. The three annealing ovens 135,
140, and 145 may be either a hot air oven with co- or
countercurrent hot air flow, which can be operated from 50.degree.
C. to 150.degree. C. or a hot water-oven, wherein the filaments 110
are oriented at temperatures from 50.degree. C. to 98.degree. C. At
the exit of the first annealing oven 135, the filaments 110 are
passed onto a third set of rollers 150 that may be run at a
different (higher or lower) speed than the second set of rollers
130. The linear velocity ratio of the third set of rollers 150
located after the oven to the second set of rollers 130 located in
front of the oven may be referred to as either a stretching or
relaxation ratio. At the exit of the second annealing oven 140, the
filaments 110 are passed onto a fourth set of rollers 155 that may
be run at a different (higher or lower) speed than the third set of
rollers 150. At the exit of the third annealing oven 145, the
filaments 110 are passed onto a fifth set of rollers 160 that may
be run at a different (higher or lower) speed than the fourth set
of rollers 155. In some embodiments, the annealing ovens 135, 140,
and 145 may be replaced with heated godets 320 and 330, as depicted
in FIG. 1B.
[0054] The stretched filament may optionally undergo further
post-extrusion processing (e.g., annealing, cutting, etc.).
Artificial Turf
[0055] One or more embodiments of the stretched filaments described
herein may be used to form an artificial turf field. Referring to
FIG. 2, depicted is a cutaway view of an artificial turf field 200
according to one or more embodiments shown and/or described herein.
The artificial turf field 200 comprises a primary backing 205
having a top side 210 and a bottom side 215; and at least one
stretched filament 220 as previously described herein. The at least
one stretched filament 220 is affixed to the primary backing 205
such that the at least one stretched filament 220 provides a tufted
face 225 extending outwardly from the top side 210 of the primary
backing 205. As used herein, "affix," "affixed," or "affixing"
includes, but is not limited to, coupling, attaching, connecting,
fastening, joining, linking or securing one object to another
object through a direct or indirect relationship. The tufted face
225 extends from the top side 210 of the primary backing 205, and
can have a cut pile design, where the stretched filament loops may
be cut, either during tufting or after, to produce a pile of single
stretched filament ends instead of loops.
[0056] The primary backing 205 can include, but is not limited to,
woven, knitted, or non-woven fibrous webs or fabrics made of one or
more natural or synthetic fibers or yarns, such as polypropylene,
polyethylene, polyamides, polyesters, and rayon. The artificial
turf field 200 may further comprise a secondary backing 230 bonded
to at least a portion of the bottom side 215 of the primary backing
205 such that the at least one stretched filament 220 is affixed in
place to the bottom side 215 of the primary backing 205. The
secondary backing 230 may comprise polyurethane (including, for
example, polyurethane supplied under the name ENFORCER.TM. or
ENHANCER.TM. available from The Dow Chemical Company (Midland,
Mich.)) or latex-based materials, such as, styrene-butadiene latex,
or acrylates.
[0057] The primary backing 205 and/or secondary backing 230 may
have apertures through which moisture can pass. The apertures may
be generally annular in configuration and are spread throughout the
primary backing 205 and/or secondary backing 230. Of course, it
should be understood that there may be any number of apertures, and
the size, shape and location of the apertures may vary depending on
the desired features of the artificial turf field 200.
[0058] The artificial turf field 200 may be manufactured by
providing at least one stretched filament 220 as described herein
and affixing the at least one stretched filament 220 to a primary
backing 205 such that that at least one stretched filament 220
provides a tufted face 225 extending outwardly from a top side 210
of the primary backing 205. The artificial turf field 200 may
further be manufactured by bonding a secondary backing 230 to at
least a portion of the bottom side 215 of the primary backing 205
such that the at least one stretched filament 220 is affixed in
place to the bottom side 215 of the primary backing 205.
[0059] The artificial turf field 200 may optionally comprise a
shock absorption layer underneath the secondary backing 230 of the
artificial turf field. The shock absorption layer (not shown) can
be made from polyurethane, PVC foam plastic or polyurethane foam
plastic, a rubber, a closed-cell crosslinked polyethylene foam, a
polyurethane underpad having voids, elastomer foams of polyvinyl
chloride, polyethylene, polyurethane, and polypropylene.
Non-limiting examples of a shock absorption layer are DOW.RTM.
ENFORCER.TM. Sport Polyurethane Systems, and DOW.RTM. ENHANCER.TM.
Sport Polyurethane Systems, both available from The Dow Chemical
Company (Midland, Mich.).
[0060] The artificial turf field 200 may optionally comprise an
infill material. Suitable infill materials include, but are not
limited to, mixtures of granulated rubber particles like SBR
(styrene butadiene rubber) recycled from car tires, EPDM
(ethylene-propylene-diene monomer), other vulcanized rubbers or
rubber recycled from belts, thermoplastic elastomers (TPEs) and
thermoplastic vulcanizates (TPVs).
[0061] The artificial turf field 200 may optionally comprise a
drainage system. The drainage system allows water to be removed
from the artificial turf field and prevents the field from becoming
saturated with water. Nonlimiting examples of drainage systems
include stone-based drainage systems, EXCELDRAIN.TM. Sheet 100,
EXCELDRAIN.TM. Sheet 200, AND EXCELDRAIN.TM. EX-T STRIP (available
from American Wick Drain Corp., Monroe, N.C.).
[0062] The embodiments described herein may be further illustrated
by the following non-limiting examples.
Test Methods
Density
[0063] Density is measured according to ASTM D792, and is reported
in grams per cubic centimeter (g/cm.sup.3 or g/cc).
Melt Index
[0064] Melt index, or I.sub.2, is measured according to ASTM D1238
at 190.degree. C. and 2.16 kg, and is reported in grams eluted per
10 minutes. Melt index, or I.sub.10, is measured in accordance with
ASTM D1238 at 190.degree. C. and 10 kg.
Melt Flow Rate
[0065] Melt flow rate, MFR.sub.2, for propylene-based polymers is
measured in accordance with ASTM D1238 at 230.degree. C. and 2.16
kg, and is reported in grams eluted per 10 minutes. Melt flow rate,
or MFR.sub.10, for propylene-based polymers is measured in
accordance with ASTM D1238 at 230.degree. C. and 10 kg, and is
reported in grams eluted per 10 minutes.
Differential Scanning Calorimetry (DSC)
[0066] Baseline calibration of the TA Instrument's DSC Q1000 is
performed by using the calibration wizard in the software. First, a
baseline is obtained by heating the cell from -90.degree. C. to
300.degree. C. without any sample in the aluminum DSC pan. After
that, sapphire standards are used according to the instructions in
the wizard. Then about 3-4 mg of a fresh indium sample is analyzed
by heating the sample to 100.degree. C. to equilibrate and followed
by heating the sample from 100.degree. C. to 180.degree. C. at a
heating rate of 10.degree. C./min. The heat of fusion and the onset
of melting of the indium sample are determined and checked to be
within 1.3.degree. C. from 156.6.degree. C. for the onset of
melting and within 0.8 J/g from 28.71 J/g for the heat of
fusion.
[0067] Samples of polymer are pressed into a thin film at a
temperature of 160.degree. C. About 5 to 8 mg of sample is weighed
out and placed in a DSC pan. A lid is crimped on the pan to ensure
a closed atmosphere. The sample pan is placed in the DSC cell and
then heated at a high rate of 10.degree. C./min to 230.degree. C.
The sample is kept at this temperature for about 3 minutes. Then
the sample is cooled at a rate of 10.degree. C./min to -40.degree.
C., and kept isothermally at that temperature for 3 minutes. The
sample is then heated at a rate of 10.degree. C./min until melting
is complete or 230.degree. C. The resulting enthalpy curves from
the second scan analyzed for DSC melting point and heat of fusion.
The DSC % crystallinity is calculated for propylene-based polymers
as follows:
DSC % Crystallinity = .DELTA. H f obs 165 J g .times. 100 %
##EQU00001##
where .DELTA.H.sub.f.sup.obs is the observed heat of fusion taken
from the "second melting curve."
Fourier Transform Infrared Spectroscopy (FTIR)
[0068] The amount of grafting was determined by Fourier Transform
Infrared Spectroscopy (FTIR). In particular, 2 g of the grafted
polymer was dissolved in 150 mL toluene. The mixture was heated and
stirred until all of the grafted polymer was in solution. The
solution was cooled for 10 minutes, and 100 mL of cold methane was
added to form a precipitate. The solution was suctioned through #2
qualitative filter paper to collect the precipitate. The
precipitate was dried in a forced air oven for 1 hour at
100.degree. C., then pressed into a film. The film was then
processed using an FTIR spectrometer.
Basis Weight
[0069] The basis weight of filaments is typically reported in the
industry by the dtex value. The dtex of a monofilament is equal to
the weight in grams of 10 km of the monofilament.
Tensile Strength
[0070] The tensile strength of filaments is measured on according
to ISO 527.
Elongation
[0071] Elongation was measured according to ISO 527.
Shrinkage
[0072] The shrinkage 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. Shrinkage is then
calculated as: (length before-length after)/length before
*100%.
Tenacity
[0073] Tenacity is determined using a Zwick tensile tester,
operating on a 260 mm length of the monofilament, and using an
extension speed of 250 mm/minute until the filament breaks. The
tenacity (in cN/dtex) is the tensile stress (in cN) at break
divided by the linear weight (in dtex). The linear weight (in dtex)
of a monofilament is equal to the weight of weighing 50 meters of
the monofilament.
Adhesion
[0074] Samples were prepared by applying a polyurethane (PU)
reaction mixture to polyethylene terephthalate (PET) film at a
thickness of 0.76 mm using a wet-film applicator. One filament was
carefully married to the coating, making an effort to minimize the
inclusion of air pockets. The PET/PU/filament sample was placed
between two plates of preheated safety glass to maintain sample
flatness, then placed in an 85.degree. C. oven for five (5) minutes
to cure the PU. Samples were conditioned for seven (7) days to
allow the PU to fully cure. For each filament composition, the
measurement was repeated six (6) times. The delamination of the
filament from the PU was initiated by hand and continued on an
Instron tensile tester. The adhesion force was recorded.
Examples
[0075] The following conducted examples illustrate one or more of
the features of the stretched filaments of the present disclosure.
A functionalized polymer was prepared and used to prepare a blend
including the functionalized polymer and a non-functionalized
polyolefin. The blend was also used to prepare stretched filaments.
Testing was carried out on the stretched filaments.
Functionalized Polymer Preparation
[0076] An imidized propylene-based elastomer or plastomer resin was
produced by a two-step process. First, a propylene-based elastomer
or plastomer was grafted with maleic anhydride (MAH). The
MAH-grafted polymer was then further reacted with a diamine. A
schematic of the reaction using N-ethylethylendiamine is shown
below:
##STR00002##
[0077] The grafting experiments were completed on a Coperion 25 mm
twin-screw reactive extrusion line. The reactive extrusion line had
12 barrel sections and 9 temperature zones. Maleic anhydride was
dissolved in methyl ethyl ketone (MEK) solvent, at 50 wt. % maleic
anhydride, based on the weight of the solution. The maleic
anhydride was added to the MEK in a flask and stirred overnight
with a magnetic stirrer bar. The MEK solvent, maleic anydride, and
peroxide were injected in Barrel #4 (temperature zone 3) of the
extruder. The liquid pump system was an ISCO D1000 positive
displacement pump, commercially available as Alltech HPLC pump,
model 627.
[0078] VERSIFY.TM. 3000 propylene-ethylene copolymer, available
from The Dow Chemical Company (Midland, Mich.), was added into the
extruder using a K-Tron model KCLKT20 twin-screw, loss-in-weight
feeder. The feed rate was 15 lb/h at the fixed 200 rpm screw
speed.
[0079] Once the MAH graft process was completed, the imidization
step was performed using N-ethylethylenediamine (DEDA, CAS
110-72-5). The reaction was run in excess of DEDA to minimize the
risk of cross-linking and push the conversion of the reaction to
completion. Samples were prepared using a 2.5:1 molar ratio of
primary amine to MAH content.
[0080] The amount of grafting was determined by Fourier Transform
Infrared Spectroscopy (FTIR), according to the method described
above.
[0081] Table 1 provides selected properties of the functionalized
propylene-based plastomer or elastomer.
TABLE-US-00001 TABLE 1 DSC Grafted Density MFR.sub.2 Melting DSC
level Polymer (g/cc) (g/10 min) Point Crystallinity (wt %)
Functionalized 0.898 7.2 116.degree. C. 20.8% 0.5 Propylene-Based
Plastomer or Elastomer
[0082] Polymer Blend
[0083] A blend including a functionalized polymer and a
non-functionalized polyolefin was prepared as outlined in Table 2.
Various examples and comparative examples (Examples 1 and 2 and
Comparative Examples 1 and 2) included DOWLEX.TM. SC 2107G,
available from The Dow Chemical Company (Midland, Mich.), as the
non-functionalized polyolefin. DOWLEX.TM. SC 2107G is a linear low
density polyethylene (LLDPE) resin with a density of 0.917 g/cc, as
measured according to ASTM D792, melt index, I.sub.2, of 2.3 g/10
min, measured according to ASTM D1238 at 190.degree. C., 2.16 kg,
and a melt flow ratio, I.sub.10/I.sub.2, of from 6 to 14, measured
according to ASTM D1238 (190.degree. C. and 10 kg). A third example
(Example 3) included Braskem D105.02, available from Braskem (Sao
Paolo, Brazil), as the non-functionalized polyolefin. Braskem
D105.02 is a non-functionalized polypropylene homopolymer with a
MFR.sub.2 of 3 g/10 min measured according to ASTM D1238 at
230.degree. C., 2.16 kg.
[0084] In particular, two examples (Examples 1 and 2) were prepared
by mixing DOWLEX.TM. SC 2107G with 5% of the functionalized
propylene-based plastomer or elastomer in Table 1 and 10% of the
functionalized propylene-based plastomer or elastomer in Table 1,
respectively. A third example (Example 3) was prepared by mixing
Braskem D105.02 with 10% of the functionalized propylene-based
plastomer or elastomer in Table 1.
[0085] Two comparative examples were additionally prepared. One
comparative example (Comparative Example 1) included only
DOWLEX.TM. SC 2107G. The second comparative example (Comparative
Example 2) included DOWLEX.TM. SC 2107G and 5% functionalized
polyethylene in Table 1. Table 2 provides the contents of the
various examples in wt. %.
Stretched Filament
[0086] The stretched filaments were prepared from the examples. The
filament formulations are presented as wt. % of the total filament
formulation in Table 2 below. The additives, color (color
masterbatch BASF Sicolen 85125345) and a processing aid (Argus
ARX-741) were blended with the polymer compositions prior to
extrusion. Each of the filaments was prepared on a Collins fiber
spinning line (See FIG. 1B) as described herein.
TABLE-US-00002 TABLE 2 Comp. Comp. Example 1 Example 2 Example 3
Ex. 1 Ex. 2 DOWLEX .TM. 89.3 84.6 0 94 89.3 SC 2107G (non-
functionalized polyethylene) Braskem 0 0 84.6 0 0 D105.02 (non-
functionalized polypropylene) Functionalized 0 0 0 0 4.7
Polyethylene (functionalized ENGAGE .TM.) Functionalized 4.7 9.4
9.4 0 0 Propylene- based Elastomer or Plastomer (Functionalized
VERSIFY .TM. 3000) color 5.0 5.0 5.0 5.0 5.0 masterbatch BASF
Sicolen 85125345 Argus ARX- 1.0 1.0 1.0 1.0 1.0 741 Total 100 100
100 100 100
[0087] Table 3 provides specific conditions of the equipment used
in preparing the filaments.
TABLE-US-00003 TABLE 3 Parameter Value Die type Mexican Hat (total
4 holes) Extruder Temperature melt T 220.degree. C. Distance
die-to-water bath 40 mm (see FIG. 1) Temperature first godet
97.degree. C. Temperature second, third, and fourth 112.degree. C.
godets Speed of fourth godet 140 m/min
[0088] The filaments shown in Table 4--Example 1, Example 2,
Example 3, Comp. Ex. 1, and Comp. Ex. 2--were produced at stretch
ratio of 5. In this case, the speed of the first godet was 28 m/min
(speed of final godet/5). The filaments shown in Table 5--Example 1
and Comp. Ex. 2--were produced with stretch ratio of 3.66. In this
case, the speed of the first godet was 38.25 m/min (speed of final
godet/3.66). The stretched filaments were tested for shrinkage,
tenacity, elongation, and adhesion to polyurethane, and the results
are shown in Tables 4 and 5. Tenacity and elongation were measured
on a Zwick tensile tester on a filament length of 250 mm and
extension rate of 250 mm/min until the filament breaks. Tenacity is
defined as the tensile force at break divided by the linear weight
(dtex). Elongation is the strain at break. Adhesion to polyurethane
was measured by according to the method provided above. The
adhesion force was recorded and is reported in Tables 4 and 5.
TABLE-US-00004 TABLE 4 Filament Results at Stretch Ratio of 5 Comp.
Comp. Example 1 Example 2 Example 3 Ex. 1 Ex. 2 Shrinkage (%) 13.8
11.7 16 12.6 Broke Tenacity 1.12 1.23 2.05 1.00 during (cN/dtex)
Elongation (%) 60.8 64.2 78.1 51.4 stretching Adhesion to 0.29 0.41
0.20 0.12 Polyurethane (PU) (N)
TABLE-US-00005 TABLE 5 Filament Results at Stretch Ratio of 3.66
Example 1 Comp. Ex. 2 Shrinkage 8.0 10.5 (%) Tenacity 0.73 0.64
(cN/dtex) Elongation 83.8 73.7 (%) Adhesion to 0.26 0.15 PU (N)
[0089] As shown in Table 4, tenacity, elongation, and adhesion to
polyurethane increased with the addition of a functionalized
polymer. Additionally, as shown in Tables 4 and 5, filaments
including a functionalized propylene-based plastomer or elastomer
showed improvement over filaments including a functionalized
polyethylene (Comp. Ex. 2), which broke during stretching.
[0090] Without being bound by theory, it is believed that during
functionalization of the propylene-based plastomer or elastomer,
the polymer chain is cut, making it easier for split chains to
migrate to the surface of the filament and improve adhesion to the
polyurethane. However, it is believed that functionalization of
polyethylene creates longer branches, thereby resulting in the
opposite effect. It is further believed that the longer branches
and crosslinking that occur upon functionalization of polyethylene
adversely impact the orientation of the filament, preventing the
filament from being stretched to a stretch ratio of 5 and achieving
the desired tenacity.
[0091] The dimensions and values disclosed herein are not to be
understood as being strictly limited to the exact numerical values
recited. Instead, unless otherwise specified, each such dimension
is intended to mean both the recited value and a functionally
equivalent range surrounding that value. For example, a dimension
disclosed as "40 mm" is intended to mean "about 40 mm."
[0092] Every document cited herein, if any, including any
cross-referenced or related patent or application and any patent
application or patent to which this application claims priority or
benefit thereof, is hereby incorporated herein by reference in its
entirety unless expressly excluded or otherwise limited. The
citation of any document is not an admission that it is prior art
with respect to any feature disclosed or claimed herein or that it
alone, or in any combination with any other reference or
references, teaches, suggests or discloses any such invention.
Further, to the extent that any meaning or definition of a term in
this document conflicts with any meaning or definition of the same
term in a document incorporated by reference, the meaning or
definition assigned to that term in this document shall govern.
[0093] While particular embodiments of the present disclosure have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
disclosure. It is therefore intended to cover in the appended
claims all such changes and modifications that are within the scope
of this disclosure.
* * * * *