U.S. patent application number 14/305918 was filed with the patent office on 2018-08-09 for composition including silane-grafted polyolefin.
The applicant listed for this patent is COOPER-STANDARD AUTOMOTIVE INC.. Invention is credited to Krishnamachari Gopalan, Gending Ji, Robert J. Lenhart.
Application Number | 20180223025 14/305918 |
Document ID | / |
Family ID | 63013641 |
Filed Date | 2018-08-09 |
United States Patent
Application |
20180223025 |
Kind Code |
A1 |
Gopalan; Krishnamachari ; et
al. |
August 9, 2018 |
COMPOSITION INCLUDING SILANE-GRAFTED POLYOLEFIN
Abstract
A silane-grafted polyolefin composition is disclosed, and
includes a desired reduced specific weight material. The
composition finds application in a wide array of uses, and in
particular automotive and uses such as weatherstrips, where this
composition is used in place of conventional materials such as TPV
and EPDM rubber formulations.
Inventors: |
Gopalan; Krishnamachari;
(Troy, MI) ; Lenhart; Robert J.; (Fort Wayne,
IN) ; Ji; Gending; (Waterloo, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
COOPER-STANDARD AUTOMOTIVE INC. |
Novi |
MI |
US |
|
|
Family ID: |
63013641 |
Appl. No.: |
14/305918 |
Filed: |
June 16, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61835157 |
Jun 14, 2013 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60J 10/17 20160201;
B60J 10/16 20160201; B60J 10/15 20160201; C08F 255/04 20130101;
C08F 255/00 20130101; C08F 255/04 20130101; C08F 230/08
20130101 |
International
Class: |
C08F 255/00 20060101
C08F255/00 |
Claims
1. A weatherstrip consisting essentially of a weatherstrip
composition, the weatherstrip composition consisting of: a
silane-grafted polyolefin having a density of from about 0.86
g/cm.sup.3 to about 0.96 g/cm.sup.3; and optionally one or more
additives selected from the group consisting of antistatic agents,
dyes, pigments, UV light absorbers, nucleating agents, fillers,
slip agents, plasticizers, fire retardants, lubricants, processing
aides, smoke inhibitors, anti-blocking agents, and viscosity
control agents; wherein the polyolefin is selected from the group
consisting of a propylene/.alpha.-olefin copolymer and a blend of
propylene/.alpha.-olefin copolymer with an ethylene/.alpha.-olefin
copolymer.
2. A method for manufacturing a weatherstrip comprising: grafting
silanes to a polyolefin to form a silane-grafted polyolefin;
extruding a composition comprising the silane-grafted polyolefin
having a density of from about 0.86 g/cm.sup.3 to about 0.96
g/cm.sup.3, a condensation catalyst, and optionally one or more
additives selected from the group consisting of antistatic agents,
dyes, pigments, UV light absorbers, nucleating agents, fillers,
slip agents, plasticizers, fire retardants, lubricants, processing
aides, smoke inhibitors, anti-blocking agents, and viscosity
control agents; and molding the extruded composition into the shape
of the weatherstrip; wherein the polyolefin is a
propylene/.alpha.-olefin copolymer.
3.-10. (canceled)
11. The method of claim 2, wherein the grafting is performed in a
melt.
12. The method of claim 2, wherein the grafting is performed in
solution.
13. The method of claim 2, wherein the grafting is performed in a
solid-state.
14. The method of claim 2, wherein the grafting is performed in a
swollen-state.
15-20. (canceled)
21. A weatherstrip comprising: a weatherstrip composition that
comprises: a silane-grafted polyolefin having a density of from
about 0.86 g/cm.sup.3 to about 0.96 g/cm.sup.3, wherein the
polyolefin is a propylene/.alpha.-olefin copolymer.
22.-30. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This utility application claims the priority benefit of U.S.
provisional application Ser. No. 61/835,157, filed Jun. 14, 2013,
the disclosure of which is expressly incorporated by reference
herein in its entirety.
BACKGROUND
[0002] The present disclosure relates to compositions such as
weatherstrip compositions, weatherstrips that may be used in
vehicles, and methods for forming the compositions and/or
weatherstrips.
[0003] It is common in the motor vehicle industry to fashion
decorative abrasion resistant sections for various parts of an
automobile by extruding such sections from certain polymeric
materials. Examples of typical abrasion resistant sections
manufactured by such a process include weatherstrips. These
weatherstrips are mounted on an automobile door surface and along
the perimeter of automobile doors to provide a seal between the
door and the automobile body as well as to protect both the door
and exterior objects when they come in contact with each other. The
weatherstrips may prevent wind noise, water leaks, and dust from
entering the automobile.
[0004] Automotive glass run weatherstrip formulations typically
utilize either thermoplastic vulcanizates (TPV) or ethylene
propylene diene monomer (EPDM) rubber to achieve desired
performance. TPVs are relatively easy to process but performance
can be limited and material costs tend to be high. EPDM rubber
formulations can require many ingredients (e.g., carbon black,
petroleum-based oil, zinc oxide, miscellaneous fillers such as
calcium carbonate or talc, processing aids, curatives, blowing
agents, and many other materials to meet performance requirements).
These ingredients are typically mixed together in a one or two step
process prior to shipping to an extrusion facility. At the
extrusion facility, the ingredients and rubber compound(s) are
extruded into automotive glass run weatherstrips.
[0005] The extrusion process can include many stages depending on
the type of EPDM weatherstrip being manufactured. For example,
extrusion lines of up to 80 yards in length that are powered by
natural gas and/or electricity may be required. Much of the natural
gas and/or electricity is used to fuel hot air ovens, microwaves,
infrared ovens, or other types of equipment used to vulcanize the
EPDM rubber compounds. The vulcanization process also produces
fumes that must be vented and monitored to comply with
environmental requirements. This process can be very time
consuming, costly, and environmentally unfriendly.
[0006] It would be desirable to develop new compositions and
methods for manufacturing weatherstrips which are simpler, lighter
in weight, have superior long-term load loss (LLS) (i.e., ability
to seal the glass and window for a long term), and more
environmentally friendly.
BRIEF DESCRIPTION
[0007] The present disclosure relates to compositions including
silane-grafted polyolefins.
[0008] The compositions are useful in the production of
weatherstrips, for example glass run weatherstrips for use in
vehicles. The weatherstrips may be components of glass sealing
systems with good surface appearance, good weathering, and good
sealing capability against wind, noise, and water leaks.
[0009] Disclosed in embodiments is a weatherstrip comprising a
silane-grafted polyolefin.
[0010] Disclosed in other embodiments is a method for manufacturing
a composition that finds use as a weatherstrip. The method includes
extruding a composition that contains a silane-grafted polyolefin.
The extruded composition is molded into the shape of the
weatherstrip. The method may further include grafting silanes to a
polyolefin to form the silane-grafted polyolefin.
[0011] Disclosed in further embodiments is a composition comprising
a silane-grafted polyolefin.
[0012] These and other non-limiting characteristics of the
disclosure are more particularly disclosed below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The following is a brief description of the drawings, which
are presented for the purposes of illustrating the exemplary
embodiments disclosed herein and not for the purposes of limiting
the same.
[0014] FIG. 1 is a side perspective view of a portion of an
automotive vehicle.
[0015] FIG. 2 is a cross-sectional view of a beltline weatherstrip
portion.
[0016] FIG. 3 is a cross-sectional view of a below belt
weatherstrip portion.
[0017] FIG. 4 is a graph illustrating the stress/strain behavior of
a composition of the present disclosure compared to two EPDM
compounds.
DETAILED DESCRIPTION
[0018] A more complete understanding of the components, processes
and apparatuses disclosed herein can be obtained by reference to
the accompanying drawings. These figures are merely schematic
representations based on convenience and the ease of demonstrating
the present disclosure, and are, therefore, not intended to
indicate relative size and dimensions of the devices or components
thereof and/or to define or limit the scope of the exemplary
embodiments.
[0019] Although specific terms are used in the following
description for the sake of clarity, these terms are intended to
refer only to the particular structure of the embodiments selected
for illustration in the drawings, and are not intended to define or
limit the scope of the disclosure. In the drawings and the
following description below, it is to be understood that like
numeric designations refer to components of like function.
[0020] The singular forms "a," "an," and "the" include plural
referents unless the context clearly dictates otherwise.
[0021] Numerical values in the specification and claims of this
application should be understood to include numerical values which
are the same when reduced to the same number of significant figures
and numerical values which differ from the stated value by less
than the experimental error of conventional measurement technique
of the type described in the present application to determine the
value.
[0022] All ranges disclosed herein are inclusive of the recited
endpoint and independently combinable (for example, the range of
"from 2 to 10" is inclusive of the endpoints, 2 and 10, and all the
intermediate values). The endpoints of the ranges and any values
disclosed herein are not limited to the precise range or value;
they are sufficiently imprecise to include values approximating
these ranges and/or values.
[0023] A value modified by a term or terms, such as "about" and
"substantially," may not be limited to the precise value specified.
The approximating language may correspond to the precision of an
instrument for measuring the value. The modifier "about" should
also be considered as disclosing the range defined by the absolute
values of the two endpoints. For example, the expression "from
about 2 to about 4" also discloses the range "from 2 to 4."
[0024] FIG. 1 shows a portion of an automotive vehicle 100
including a front door 102. The front door 102 includes a window
opening 104 and a window 106 that can be selectively raised and
lowered relative to the door. A weatherstrip 110 surrounds
selective perimeter portions of the window (e.g., side and upper
portions when the window is closed). This weatherstrip 110 may be a
glass run weatherstrip. The weatherstrip 110 may be formed as
separate weatherstrip portions that engage different perimeter
portions of the window. In some embodiments, the weatherstrip
portions are integrally joined together as a module or a single
weatherstrip assembly.
[0025] A lower edge of the window opening, as defined by the door,
may be referred to as a beltline 120. Extending along the beltline
120 is a beltline weatherstrip portion or beltline portion of the
weatherstrip module identified as 122.
[0026] A cross-sectional view of the beltline weatherstrip 122 is
shown in FIG. 2. The beltline weatherstrip includes a body 124
formed as an inverted, generally U-shaped component in
cross-section having first and second legs 126, 128 having inwardly
extending gripping portions 130 that engage a door panel 132. The
beltline weatherstrip 122 further includes a seal lip 134 that is
flexible relative to the body, and is oftentimes formed of a
different material (e.g., a lower durometer rubber or plastic) than
the rubber or EPDM polymer composition of the body 124. A low
friction material 136 is typically provided along that portion of
the seal lip 134 that is configured for sliding engagement with the
movable glass on the vehicle door window 106. It is not uncommon
for the beltline weatherstrip 122 to be formed as a co-extruded
structure where the different regions or portions of the integrated
beltline weatherstrip are formed from different materials in order
to serve different functions. For example, the body 124 may be a
higher durometer material while the seal lip 134 requires
flexibility and thus is preferably a lower durometer material that
may also incorporate a low friction material.
[0027] Illustrated in FIG. 3 is a cross-sectional view of another
or below belt weatherstrip portion 140 of the glassrun
weatherstrip. For example, below belt portions 142, 144 located in
an interior cavity of the door 102 may have a configuration as
generally illustrated in FIG. 3. Specifically, the below belt
weatherstrip portion has an outer rigid support member 146 shown
here as a generally U-shaped component that receives or supports
the below belt weatherstrip portion 140. Upstanding legs 148, 150
form a channel with base 152 that receives the weatherstrip portion
140. The weatherstrip portion 140 is unsupported, i.e., it does not
have a rigid support member encased within the rubber or EPDM
polymer of which the weatherstrip portion is made. First and second
legs 160, 162 extend generally upwardly and outwardly from a base
portion 164 so that this below belt weatherstrip portion 140
likewise has a generally U-shaped conformation adapted to receive a
perimeter edge of the window 106. Retaining flanges 166, 168 are
provided along outer edges of the base portion 164 while flexible
seal lips 170, 172 are flexibly joined at outer ends of the
respective legs 160, 162. Again, the flexible seal lips 170, 172,
and even the retaining flanges 166, 168 may be formed of a
different material than the remaining rubber of the weatherstrip
portion 140. Further, those portions of the body (comprised of legs
160, 162 and base 164) that are adapted to engage the window 106
preferably have a hardened surface, while the seal lips 170, 172
may have a low friction surface where the seal lips engage the
window edge.
[0028] The weatherstrips are formed from a composition including a
silane-grafted polyolefin. The silane-grafted polyolefin may be a
silane-grafted polyolefin elastomer. The silane-grafted polyolefin
may be cross-linked upon exposure to moisture and/or heat to form
an elastomeric material. The cross-linked polyolefin can be used in
place of existing TPV and EPDM rubber formulations to manufacture,
for example, automotive weatherstrips.
[0029] Advantageously, the compositions may require a limited
number of ingredients (e.g., 10, 9, 8, 7, 6, 5, 4, or 3
ingredients). The ingredients may be combined at an extruder during
extrusion (e.g., a single-step Monosil process or a two-step
Sioplas process), thereby eliminating the need for additional steps
of mixing and shipping rubber compounds prior to extrusion.
[0030] FIG. 4 illustrates the superior stress/strain behavior of an
exemplary material of the present disclosure relative to two
existing EPDM materials. In particular, FIG. 4 displays a smaller
area between the stress/strain curves for the silane-grafted and
cross-linked polyolefin, versus the areas between the stress/strain
curves for EPDM compound A and EPDM compound B. This can be
desirable for most automotive glass run weatherstrip applications.
Elastomeric materials typically have non-linear stress-strain
curves with a significant loss of energy when repeatedly stressed.
The compositions of the present disclosure may exhibit greater
elasticity (e.g., have linear curves and exhibit very low energy
loss).
[0031] The compositions of the present disclosure also reduce the
carbon footprint of extrusion plants used to make the weatherstrips
or other articles because large natural gas and/or electrical ovens
may not be required for vulcanization. Instead, more efficient low
pressure steam chambers can be utilized to vulcanize the
silane-grafted polyolefin with minimal fume evolution. In some
embodiments, the compositions of the present disclosure are curable
at room temperature (e.g., at a humidity of at least 55%). Cure
times may be reduced at higher temperatures and/or higher
pressures.
[0032] The specific gravity of the silane-grafted and cross-linked
polyolefins of the present disclosure may be lower than the
specific gravities of existing TPV and EPDM formulations. The
reduced specific gravity of the materials leads to lower weight
parts, thereby helping automakers meet increasing demands for
improved fuel economy. For example, the specific gravity of a
representative material of the present disclosure may be from about
0.86 g/cm.sup.3 to about 0.96 g/cm.sup.3 as compared to presently
used materials such as TPV which may have a specific gravity of
from 0.95 to 1.2 g/cm.sup.3 and EPDM which may gave a specific
gravity of from 1.0 to 1.35 g/cm.sup.3.
[0033] The polyolefin elastomer may be a block copolymer, an
ethylene/.alpha.-olefin copolymer, a propylene/.alpha.-olefin
copolymer, EPDM, or a mixture of two or more of any of these
materials. Exemplary block copolymers include those sold under the
trade names INFUSE.TM. (the Dow Chemical Company) and SEPTON.TM.
V-SERIES (Kuraray Co., LTD.). Exemplary ethylene/.alpha.-olefin
copolymers include those sold under the trade names VISTAMAXX.TM.
(e.g., VISTAMAXX 6102) (Exxon Mobil Chemical Company), TAFMER.TM.
(e.g., TAFMER DF710) (Mitsui Chemicals, Inc.), and ENGAGE.TM.
(e.g., ENGAGE 8150) (the Dow Chemical Company). Exemplary
propylene/.alpha.-olefin copolymers TAFMER.TM. XM grades (Exxon
Mobil Chemical Company). The EPDM may have a diene content of from
about 0.5 to about 10 weight percent
[0034] In some embodiments, the polyolefin is selected from the
group consisting of: homopolymers of an olefin or a blend of
homopolymers, copolymers of two or more olefins or a blend of
copolymers, and a blend of homopolymers with copolymers
[0035] The olefin may be selected from ethylene, propylene,
1-butene, 1-propene, 1-hexene, and 1-octene. The polyolefin may be
produced by any process (e.g., using gas phase and solution based
using metallocene catalysis and Ziegler-Natta catalysis) and
optionally using any catalyst suitable for polymerizing ethylene
and .alpha.-olefins. A metallocene catalyst may be used to produce
low density ethylene/.alpha.-olefin polymers.
[0036] Suitable polyethylenes include but are not limited to
polyethylene obtained by homopolymerization of ethylene or
copolymerization of ethylene and a higher 1-olefin comonomer.
[0037] Suitable polypropylenes include but are not limited to
polypropylene obtained by homopolymerization of propylene or
copolymerization of propylene and an olefin comonomer.
[0038] The term "comonomer" refers to olefin comonomers which are
suitable for being polymerized with olefin monomers, such as
ethylene or propylene monomers. Comonomers may comprise but are not
limited to aliphatic C.sub.2-C.sub.20 .alpha.-olefins. Examples of
suitable aliphatic C.sub.2-C.sub.20 .alpha.-olefins include
ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene,
1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene,
1-octadecene and 1-eicosene. In an embodiment, the comonomer is
vinyl acetate. The term "copolymer" refers to a polymer, which is
made by linking more than one type of monomer in the same polymer
chain. The term "homopolymer" refers to a polymer which is made by
linking olefin monomers, in the absence of comonomers. The amount
of comonomer can, in some embodiments, be from greater than 0 to
about 12 weight percent based on the weight of the polyolefin,
including from greater than 0 to about 9 weight percent and from
greater than 0 to about 7 weight percent. In some embodiments, the
comonomer content is greater than about 2 mole percent of the final
polymer, including greater than about 3 mole percent and greater
than about 6 mole percent. The comonomer content may be less than
or equal to about 30 mole percent. A copolymer can be a random or
block (heterophasic) copolymer. In some embodiments, the polyolefin
is a random copolymer of propylene and ethylene.
[0039] The polyethylene for use in the present disclosure can be
classified into several types including, but not limited to, LDPE
(Low Density Polyethylene), LLDPE (Linear Low Density
Polyethylene), and HDPE (High Density Polyethylene). In another
classification, the polyethylene can be classified as Ultra High
Molecular Weight (UHMW), High Molecular Weight (HMW), Medium
Molecular Weight (MMW) and Low Molecular Weight (LMW). The
polyethylene may be an ultra low density ethylene elastomer. The
ultra low density ethylene elastomer may have a density of 0.85
g/cm.sup.3 or greater, including from about 0.88 to about 0.92
g/cm.sup.3.
[0040] The polyolefin may include a LDPE/silane copolymer or
blend.
[0041] The polyolefin, such as polyethylene, can be produced using
any catalyst known in the art including, but not limited to,
chromium catalysts, Ziegler-Natta catalysts, metallocene catalysts
or post-metallocene catalysts.
[0042] In some embodiments, the polyolefin has a molecular weight
distribution M.sub.w/M.sub.n of less than or equal to about 5,
including less than or equal to about 4, from about 1 to about 3.5,
and from about 1 to about 3.
[0043] The polyolefin may have a melt viscosity in the range of
from about 2,000 cP to about 50,000 cP as measured using a
Brookfield viscometer at a temperature of about 177.degree. C. In
some embodiments, the melt viscosity is from about 4,000 cP to
about 40,000 cP, including from about 5,000 cP to about 30,000 cP
and from about 6,000 cP to about 18,000 cP.
[0044] The polyolefin may have a melt index (T2), measured at
190.degree. C. under a 2.16 kg load, of from about 20.0 g/10 min to
about 3,500 g/10 min, including from about 250 g/10 min to about
1,900 g/10 min and from about 300 g/10 min to about 1,500 g/10 min.
In some embodiments, the polyolefin has a fractional melt index of
from 0.5 g/10 min to about 3,500 g/10 min.
[0045] The polyolefin may be polymerized in two reactors, wherein a
first polymer is polymerized in the first reactor and a second
polymer is polymerized in the second reactor. The second polymer
may be of a higher molecular weight, a different density, and/or be
heterogeneous. The reactors may be connected in series or in
parallel.
[0046] In some embodiments, a blend of two or more polyolefins is
silanated and/or cured. The blend may include an
ethylene/.alpha.-olefin polymer and a propylene/.alpha.-olefin
polymer.
[0047] The polymers and resins of the present disclosure may be
treated with one or more stabilizers (e.g., antioxidants). The
polymers may be treated before grafting, after grafting, before
crosslinking, and/or after crosslinking. Other additives may also
be included. Non-limiting examples of additives include antistatic
agents, dyes, pigments, UV light absorbers, nucleating agents,
fillers, slip agents, plasticizers, fire retardants, lubricants,
processing aides, smoke inhibitors, anti-blocking agents, and
viscosity control agents. The antioxidant(s) may be present in an
amount of less than 0.5 weight percent, including less than 0.2
weight percent of the composition.
[0048] In some embodiments, the density of the polyolefin elastomer
is less than 1.0 g/cm.sup.3, including less than about 0.92
g/cm.sup.3. The density may be from about 0.85 g/cm.sup.3 to about
0.96 g/cm.sup.3. In some embodiments, the density is at least 0.84
g/cm.sup.3, including at least about 0.862 g/cm.sup.3.
[0049] The polyolefin elastomer may be present in an amount of from
greater than 0 to about 100 weight percent of the composition. In
some embodiments, the amount of polyolefin elastomer is from about
30 to about 70 weight percent.
[0050] The percent crystallinity of the polyolefin elastomer may be
less than about 40%, less than about 35%, less than about 30%, less
than about 25%, or less than about 20%. The percent crystallinity
may be at least about 10%. In some embodiments, the crystallinity
is in the range of from about 2% to about 60%.
[0051] The silane grafted to the polyolefin may be selected from
alkoxysilanes, silazanes and siloxanes.
[0052] Non-limiting examples of silazanes include
hexamethyldisilazane (HMDS or Bis(trimethylsilyl)amine).
Non-limiting examples of siloxane compounds include
polydimethylsiloxane (PDMS) and octamethylcyclotetrasiloxane.
[0053] In some embodiments, the silane is an alkoxysilane. As used
herein, the term "alkoxysilane" refers to a compound that comprises
a silicon atom, at least one alkoxy group and at least one other
organic group, wherein the silicon atom is bonded with the organic
group by a covalent bond. Preferably, the alkoxysilane is selected
from alkylsilanes; acryl-based silanes; vinyl-based silanes;
aromatic silanes; epoxy-based silanes; amino-based silanes and
amines that possess --NH.sub.2, --NHCH.sub.3 or
--N(CH.sub.3).sub.2; ureide-based silanes; mercapto-based silanes;
and alkoxysilanes which have a hydroxyl group (i.e., --OH). An
acryl-based silane may be selected from the group comprising
beta-acryloxyethyl trimethoxysilane; beta-acryloxy propyl
trimethoxysilane; gamma-acryloxyethyl trimethoxysilane;
gamma-acryloxypropyl trimethoxysilane; beta-acryloxyethyl
triethoxysilane; beta-acryloxypropyl triethoxysilane;
gamma-acryloxyethyl triethoxysilane; gamma-acryloxypropyl
triethoxysilane; beta-methacryloxyethyl trimethoxysilane;
beta-methacryloxypropyl trimethoxysilane; gamma-methacryloxyethyl
trimethoxysilane; gamma-methacryloxypropyl trimethoxysilane;
beta-methacryloxyethyl triethoxysilane; beta-methacryloxypropyl
triethoxysilane; gamma-methacryloxyethyl triethoxysilane;
gamma-methacryloxypropyl triethoxysilane;
3-methacryloxypropylmethyl diethoxysilane. A vinyl-based silane may
be selected from the group comprising vinyl trimethoxysilane; vinyl
triethoxysilane; p-styryl trimethoxysilane,
methylvinyldimethoxysilane, vinyldimethylmethoxysilane,
divinyldimethoxysilane, vinyltris(2-methoxyethoxy)silane, and
vinylbenzylethylenediaminopropyltrimethoxysilane. An aromatic
silane may be selected from phenyltrimethoxysilane and
phenyltriethoxysilane. An epoxy-based silane may be selected from
the group comprising 3-glycydoxypropyl trimethoxysilane;
3-glycydoxypropylmethyl diethoxysilane; 3-glycydoxypropyl
triethoxysilane; 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, and
glycidyloxypropylmethyldimethoxysilane. An amino-based silane may
be selected from the group comprising 3-aminopropyl
triethoxysilane; 3-aminopropyl trimethoxysilane;
3-aminopropyldimethyl ethoxysilane;
3-aminopropylmethyldiethoxysilane; 4-aminobutyltriethoxysilane;
3-aminopropyldiisopropylethoxysilane;
1-amino-2-(dimethylethoxysilyl)propane,
(aminoethylamino)-3-isobutyldimethyl methoxysilane;
N-(2-aminoethyl)-3-aminoisobutylmethyl dimethoxysilane;
(aminoethylaminomethyl)phenetyl trimethoxysilane;
N-(2-aminoethyl)-3-aminopropylmethyl dimethoxysilane;
N-(2-aminoethyl)-3-aminopropyl trimethoxysilane;
N-(2-aminoethyl)-3-aminopropyl triethoxysilane;
N-(6-aminohexyl)aminomethyl trimethoxysilane;
N-(6-aminohexyl)aminomethyl trimethoxysilane;
N-(6-aminohexyl)aminopropyl trimethoxysilane;
N-(2-aminoethyl)-1,1-aminoundecyl trimethoxysilane;
1,1-aminoundecyl triethoxysilane; 3-(m-aminophenoxy)propyl
trimethoxysilane; m-aminophenyl trimethoxysilane; p-aminophenyl
trimethoxysilane; (3-trimethoxysilylpropyl)diethylenetriamine;
N-methylaminopropylmethyl dimethoxysilane; N-methylaminopropyl
trimethoxysilane; dimethylaminomethyl ethoxysilane;
(N,N-dimethylaminopropyl)trimethoxysilane;
(N-acetylglycysil)-3-aminopropyl trimethoxysilane,
N-phenyl-3-aminopropyltrimethoxysilane,
N-phenyl-3-aminopropyltriethoxysilane,
phenylaminopropyltrimethoxysilane,
aminoethylaminopropyltrimethoxysilane, and
aminoethylaminopropylmethyldimethoxysilane. An ureide-based silane
may be 3-ureidepropyl triethoxysilane. A mercapto-based silane may
be selected from the group comprising 3-mercaptopropylmethyl
dimethoxysilane, 3-mercaptopropyl trimethoxysilane, and
3-mercaptopropyl triethoxysilane. An alkoxysilane having a hydroxyl
group may be selected from the group comprising hydroxymethyl
triethoxysilane; N-(hydroxyethyl)-N-methylaminopropyl
trimethoxysilane; bis(2-hydroxyethyl)-3-aminopropyl
triethoxysilane; N-(3-triethoxysilylpropyl)-4-hydroxy butylamide;
1,1-(triethoxysilyl)undecanol; triethoxysilyl undecanol; ethylene
glycol acetal; and N-(3-ethoxysilylpropyl)gluconamide.
[0054] The alkylsilane may be expressed with a general formula:
R.sub.nSi(OR').sub.4-n wherein: n is 1, 2 or 3; R is a C.sub.1-20
alkyl; and R' is an C.sub.1-20 alkyl.
[0055] The term "alkyl" by itself or as part of another
substituent, refers to a straight or branched or cyclic saturated
hydrocarbon group joined by single carbon-carbon bonds having 1 to
20 carbon atoms, for example 1 to 10 carbon atoms, for example 1 to
8 carbon atoms, preferably 1 to 6 carbon atoms. When a subscript is
used herein following a carbon atom, the subscript refers to the
number of carbon atoms that the named group may contain. Thus, for
example, C.sub.1-6 alkyl means an alkyl of one to six carbon atoms.
Examples of alkyl groups are methyl, ethyl, propyl, isopropyl,
butyl, isobutyl, sec-butyl, f-butyl, 2-methylbutyl, pentyl,
iso-amyl and its isomers, hexyl and its isomers, heptyl and its
isomers, octyl and its isomer, decyl and its isomer, dodecyl and
its isomers.
[0056] The term "C.sub.2-20 alkenyl" by itself or as part of
another substituent, refers to an unsaturated hydrocarbyl group,
which may be linear, or branched, comprising one or more
carbon-carbon double bonds having 2 to 20 carbon atoms. Examples of
C.sub.2-6 alkenyl groups are ethenyl, 2-propenyl, 2-butenyl,
3-butenyl, 2-pentenyl and its isomers, 2-hexenyl and its isomers,
2,4-pentadienyl and the like.
[0057] An alkylsilane may be selected from the group comprising
methyltrimethoxysilane; methyltriethoxysilane;
ethyltrimethoxysilane; ethyltriethoxysilane;
propyltrimethoxysilane; propyltriethoxysilane;
hexyltrimethoxysilane; hexyltriethoxysilane; octyltrimethoxysilane;
octyltriethoxysilane; decyltrimethoxysilane; decyltriethoxysilane;
dodecyltrimethoxysilane; dodecyltriethoxysilane;
tridecyltrimethoxysilane; dodecyltriethoxysilane;
hexadecyltrimethoxysilane; hexadecyltriethoxysilane;
octadecyltrimethoxysilane; octadecyltriethoxysilane,
trimethylmethoxysilane, methylhydrodimethoxysilane,
dimethyldimethoxysilane, diisopropyldimethoxysilane,
diisobutyldimethoxysilane, isobutyltrimethoxysilane,
n-butyltrimethoxysilane, n-butylmethyldimethoxysilane,
phenyltrimethoxysilane, phenyltrimethoxysilane,
phenylmethyldimethoxysilane, triphenylsilanol,
n-hexyltrimethoxysilane, n-octyltrimethoxysilane,
isooctyltrimethoxysilane, decyltrimethoxysilane,
hexadecyltrimethoxysilane, cyclohexylmethyldimethoxysilane,
cyclohexylethyldimethoxysilane, dicyclopentyldimethoxysilane,
tert-butylethyldimethoxysilane, tert-butylpropyldimethoxysilane,
dicyclohexyldimethoxysilane.
[0058] The silane compound may be selected from
triethoxyoctylsilane, trimethoxyoctylsilane, and a combination
thereof.
[0059] Examples of silanes include, but are not limited to, those
of the general formula
CH.sub.2.dbd.CR--(COO).sub.x(C.sub.nH.sub.2n).sub.ySiR'.sub.3,
wherein R is a hydrogen atom or methyl group; x is 0 or 1; y is 0
or 1; n is an integer from 1 to 12; each R' can be an organic group
and may be independently selected from an alkoxy group having from
1 to 12 carbon atoms (e.g., methoxy, ethoxy, butoxy), aryloxy group
(e.g., phenoxy), araloxy group (e.g., benzyloxy), aliphatic acyloxy
group having from 1 to 12 carbon atoms (e.g., formyloxy, acetyloxy,
propanoyloxy), amino or substituted amino groups (e.g., alkylamino,
arylamino), or a lower alkyl group having 1 to 6 carbon atoms. x
and y may both equal 1. In some embodiments, no more than one of
the three R' groups is an alkyl. In other embodiments, not more
than two of the three R' groups is an alkyl.
[0060] Any silane or mixture of silanes that can effectively graft
to and crosslink an olefin polymer can be used in the practice of
the present disclosure. Suitable silanes include, but are not
limited to, unsaturated silanes which include an ethylenically
unsaturated hydrocarbyl group (e.g., a vinyl, allyl, isopropenyl,
butenyl, cyclohexenyl or a gamma-(meth)acryloxy allyl group) and a
hydrolyzable group (e.g., a hydrocarbyloxy, hydrocarbonyloxy, or
hydrocarbylamino group). Non-limiting examples of hydrolyzable
groups include, but are not limited to, methoxy, ethoxy, formyloxy,
acetoxy, proprionyloxy, and alkyl, or arylamino groups. In some
embodiments, the silanes are unsaturated alkoxy silanes which can
be grafted onto the polymer. Other exemplary silanes include
vinyltrimethoxysilane, vinyltriethoxysilane,
3-(trimethoxysilyl)propyl methacrylate gamma-(meth)acryloxypropyl
trimethoxysilane), and mixtures thereof.
[0061] The silane may be present in the silane-grafted polyolefin
in an amount of from greater than 0 to about 10 weight percent,
including from about 0.5 to about 5 weight percent. The amount of
silane may be varied based on the nature of the olefin polymer, the
silane, the processing conditions, the grafting efficiency, the
application, and other factors. The amount of silane may be at
least 2 weight percent, including at least 4 weight percent or at
least 5 weight percent, based on the weight of the reactive
composition. In other embodiments, the amount of silane may be at
least 10 weight percent, based on the weight of the reactive
composition. In some embodiments, the silane content is at least 1%
based on the weight of the reactive composition.
[0062] Optionally, the crosslinking is initiated by a catalyst or
electron beam radiation. Non limiting examples of catalysts include
organic bases, carboxylic acids, and organometallic compounds
(e.g., organic titanates and complexes or carboxylates of lead,
cobalt, iron, nickel, zinc, and tin). The catalyst may be selected
from fatty acids and metal complex compounds such as metal
carboxylates; aluminum triacetyl acetonate, iron triacetyl
acetonate, manganese tetraacetyl acetonate, nickel tetraacetyl
acetonate, chromium hexaacetyl acetonate, titanium tetraacetyl
acetonate and cobalt tetraacetyl acetonate; metal alkoxides such as
aluminum ethoxide, aluminum propoxide, aluminum butoxide, titanium
ethoxide, titanium propoxide and titanium butoxide; metal salt
compounds such as sodium acetate, tin octylate, lead octylate,
cobalt octylate, zinc octylate, calcium octylate, lead naphthenate,
cobalt naphthenate, dibutyltin dioctoate, dibutyltin dilaurate,
dibutyltin maleate and dibutyltin di(2-ethylhexanoate); acidic
compounds such as formic acid, acetic acid, propionic acid,
p-toluenesulfonic acid, trichloroacetic acid, phosphoric acid,
monoalkylphosphoric acid, dialkylphosphoric acid, phosphate ester
of p-hydroxyethyl (meth)acrylate, monoalkylphosphorous acid and
dialkylphosphorous acid; acids such as p-toluenesulfonic acid,
phthalic anhydride, benzoic acid, benzenesulfonic acid,
dodecylbenzenesulfonic acid, formic acid, acetic acid, itaconic
acid, oxalic acid and maleic acid, ammonium salts, lower amine
salts or polyvalent metal salts of these acids, sodium hydroxide,
lithium chloride; organometal compounds such as diethyl zinc and
tetra(n-butoxy)titanium; and amines such as dicyclohexylamine,
triethylamine, N,N-dimethylbenzylamine,
N,N,N',N'-tetramethyl-1,3-butanediamine, diethanolamine,
triethanolamine and cyclohexylethylamine. In some embodiments, the
catalyst is selected from ibutyltindilaurate, dioctyltinmaleate,
dibutyltindiacetate, dibutyltindioctoate, stannous acetate,
stannous octoate, lead naphthenate, zinc caprylate, and cobalt
naphthenate. A single catalyst or a mixture of catalysts may be
utilized. The catalyst(s) may be present in an amount of from about
0.01 weight percent to about 1.0 weight percent, including from
about 0.25 to about 8 weight percent, based on the total weight of
the composition.
[0063] In some embodiments, the crosslinking system uses a
combination of radiation, heat, moisture, and crosslinking
agent(s). The crosslinking agent(s) may be present in an amount of
from 0.25 to 8 weight percent.
[0064] Optionally, a grafting initiator is utilized in the grafting
process. The grafting initiator may be selected from halogen
molecules, azo compounds (e.g., azobisisobutyl), carboxylic
peroxyacids, peroxyesters, peroxyketals, and peroxides (e.g., alkyl
hydroperoxides, dialkyl peroxides, and diacyl peroxides). In some
embodiments, the grafting initiator is an organic peroxide selected
from di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide,
2,5-dimethyl-2,5-di(t-butyl-peroxy)hexyne-3,
1,3-bis(t-butyl-peroxy-isopropyl)benzene,
n-butyl-4,4-bis(t-butyl-peroxy)valerate, benzoyl peroxide,
t-butylperoxybenzoate, t-butylperoxy isopropyl carbonate, and
t-butylperbenzoate, as well as bis(2-methylbenzoyl)peroxide,
bis(4-methylbenzoyl)peroxide, t-butyl peroctoate, cumene
hydroperoxide, methyl ethyl ketone peroxide, lauryl peroxide,
tert-butyl peracetate, di-t-amyl peroxide, t-amyl peroxybenzoate,
1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane,
.alpha.,.alpha.'-bis(t-butylperoxy)-1,3-diisopropylbenzene,
.alpha.,.alpha.'-bis(t-butylpexoxy)-1,4-diisopropylbenzene,
2,5-bis(t-butylperoxy)-2,5-dimethylhexane, and
2,5-bis(t-butylperoxy)-2,5-dimethyl-3-hexyne and
2,4-dichlorobenzoyl peroxide. Exemplary peroxides include those
sold under the tradename LUPEROX.TM. (available from Arkema,
Inc.).
[0065] In some embodiments, the grafting initiator is present in an
amount of from greater than 0 to about 2 weight percent of the
composition, including from about 0.15 to about 1.2 weight percent
of the composition. The amount of initiator and silane employed may
affect the final structure of the silane grafted polymer (e.g., the
degree of grafting in the grafted polymer and the degree of
crosslinking in the cured polymer). In some embodiments, the
reactive composition contains at least 100 ppm of initiator or at
least 300 ppm of initiator. The initiator may be present in an
amount from 300 ppm to 1500 ppm or 2000 ppm. The silane:initiator
weight ratio may be from about 20:1 to 400:1, including from about
30:1 to about 400:1 and from about 48:1 to about 350:1 and from
about 55:1 to about 333:1.
[0066] The grafting reaction can be performed under conditions that
optimize grafts onto the interpolymer backbone while minimizing
side reactions (e.g., the homopolymerization of the grafting
agent). The grafting reaction may be performed in the melt, in
solution, in the solid-state, and/or in a swollen-state. The
silanation may be performed in a wide-variety of equipment (e.g.,
twin screw extruders, single screw extruders, Brabenders, internal
mixers such as Banbury mixers, and batch reactors). In some
embodiments, the polyolefin, silane, and initiator are mixed in the
first stage of an extruder. The melt temperature (i.e., the
temperature at which the polymer starts melting and starts to flow)
may be from about 120.degree. C. to about 260.degree. C., including
from about 130.degree. C. to about 250.degree. C.
[0067] The composition optionally includes one or more fillers. The
filler(s) may be extruded with the silane-grafted polyolefin. The
filler(s) may be selected from metal oxides, metal hydroxides,
metal carbonates, metal sulfates, metal silicates, clays, talcs,
carbon black, and silicas. These materials may be fumed or
calcined.
[0068] The metal of the metal oxide, metal hydroxide, metal
carbonate, metal sulfate, or metal silicate may be selected from
alkali metals (e.g., lithium, sodium, potassium, rubidium, caesium,
and francium); alkaline earth metals (e.g., beryllium, magnesium,
calcium, strontium, barium, and radium); transition metals (e.g.,
zinc, molybdenum, cadmium, scandium, titanium, vanadium, chromium,
manganese, iron, cobalt, nickel, copper, yttrium, zirconium,
niobium, technetium, ruthernium, rhodium, palladium, silver,
hafnium, taltalum, tungsten, rhenium, osmium, indium, platinum,
gold, mercury, rutherfordium, dubnium, seaborgium, bohrium,
hassium, and copernicium); post-transition metals (e.g., aluminum,
gallium, indium, tin, thallium, lead, bismuth, and polonium);
lanthanides (e.g., lanthanum, Cerium, praseodymium, neodymium,
promethium, samarium, europium, gadolinium, terbium, dysprosium,
holmium, erbium, thulium, ytterbium, and lutetium); actinides
(e.g., actinium, thorium, protactinium, uranium, neptunium,
plutonium, americium, curium, berkelium, californium, einsteinium,
fermium, mendelevium, nobelium, and lawrencium); germanium;
arsenic; antimony; and astatine.
[0069] The filler(s) may be present in an amount of from greater
than 0 to about 50 weight percent, including from about 1 to about
20 weight percent and from about 3 to about 10 weight percent.
[0070] One stage silane crosslinking can involve the extrusion of a
direct mixture of the polymer resin with a silane concentrate that
includes a catalyst. The extrudate can be subsequently crosslinked
in the presence of moisture/heat. In two-stage crosslinking, silane
is first grafted to the polymer molecular chains according to known
reactions to yield a silane grafted copolymer.
##STR00001##
[0071] Subsequently, the silane-grafted copolymer is mixed with a
silanol forming condensation catalyst and then exposed to humidity
and/or heat to effect crosslinking of the copolymer in a two-step
reaction. Alternatively, the composition can be crosslinked via
`Ambicat` where the ambient moisture is sufficient to crosslink
over a longer time period (e.g., about 48 hours). First, the water
hydrolyzes the silane to produce a silanol. The silanol then
condenses to form intermolecular, irreversible Si--O--Si crosslink
sites.
##STR00002##
[0072] The amount of crosslinked silane groups, and thus the final
polymer properties, can be regulated by controlling the production
process, including the amount of catalyst used. A gel test (ASTM
D2765) can be used to determine the amount of crosslinking.
[0073] Curing may occur over a time period of from greater than 0
to about 20 hours. In some embodiments, curing takes place over a
time period of from about 1 to about 8 hours, including from about
3 to about 6 hours.
[0074] The temperature during curing may be from about 50 to about
150.degree. C., including from about 80 to about 100.degree. C. and
from about 85 to about 95.degree. C.
[0075] The humidity during curing may be from about 30 to about
100% including from about 40 to about 100% and from about 50 to
about 100%.
[0076] The number average molecular weight of the grafted polymers
may be in the range of from about 4,000 g/mol to about 30,000
g/mol, including from about 5,000 g/mol to about 25,000 g/mol and
from about 6,000 g/mol to about 14,000 g/mol. The weight average
molecular weight of the grafted polymers may be from about 8,000
g/mol to about 60,000 g/mol, including from about 10,000 g/mol to
about 30,000 g/mol.
[0077] Optionally, the compositions and/or articles formed
therefrom further include one or more TPVs and/or EPDM with or
without silane graft moieties. In some embodiments, the
compositions and/or articles further include other homopolymers,
copolymers, and/or terpolymers of ethylene (e.g., LDPE, grafted
polymers, maleated polymers, EVA copolymers, ethylene n-butyl
acrylate copolymers, and ethylene methacrylate copolymers);
homopolymers, copolymers, and/or terpolymers of propylene; rubbery
block copolymers (e.g., copolymers having A-B-A configurations,
A-B-A-B-A-B configurations, A-B configurations, and radial block
copolymers); and other olefin-based polymers. In some embodiments,
the additional polymers are present in an amount of up to 20 weight
percent of the composition.
[0078] The compositions and/or articles may also include waxes
(e.g., paraffin waxes, microcrystalline waxes, HDPE waxes, LDPE
waxes, thermally degraded waxes, byproduct polyethylene waxes,
optionally oxidized Fischer-Tropsch waxes, and functionalized
waxes).
[0079] Tackifying resins (e.g., aliphatic hydrocarbons, aromatic
hydrocarbons, modified hydrocarbons, terpens, modified terpenes,
hydrogenated terpenes, rosins, rosin derivatives, hydrogenated
rosins, and mixtures thereof) may also be included. The tackifying
resins may have a ring and ball softening point in the range of
from 70.degree. C. to about 150.degree. C. and a viscosity of less
than about 3,000 cP at 177.degree. C.
[0080] The compositions may include one or more oils. Non-limiting
types of oils include white mineral oils and naphthenic oils.
[0081] The compositions may be extruded into pellets, pillows, or
any other configuration prior to the formation of the final
article.
[0082] Non-limiting examples of articles the compositions may be
used to manufacture include weather seals such as static seals
(e.g., glass run channels) including molded details/corners,
dynamic seals (e.g., primary and secondary body and door seals,
other body closure seals, including hood-to-cowl, lift gate, etc.),
sunroof seals, convertible top seals, mirror seals, body-panel
interface seals, stationary window moldings, glass encapsulations,
cut-line seals, greenhouse moldings, occupation detector system
sensor switches, rocker seals, outer and inner belts, auxiliary and
margin seals, edge protector/gimp seals, and below-belt brackets
and channels; automotive hoses such as coolant hoses, air
conditioning hoses, and vacuum hoses; anti-vibration system (AVS)
components such as mounts (e.g., engine, body, accessory,
component), dampers, bushings, strut mounts, and isolators;
coatings such as coatings for brake lines, fuel lines, transmission
oil cooler lines, brackets, cross members, frame components, body
panels and components, suspension components, wheels, hubs,
springs, and fasteners; air deflectors, spoilers, fascia, and trim;
building, window, and door seals; boots, bellows, and grommets;
gaskets (e.g., pneumatic and/or hydraulic gaskets); wire and cable
sheathing; tires; windshield wipers and squeegees; floor mats;
pedal covers; automotive belts; conveyor belts; shoe components;
marine bumpers; O-rings; valves and seals; and springs (e.g., as
substitutes for mechanical metal springs).
[0083] This written description uses examples to describe the
disclosure, including the best mode, and also to enable any person
skilled in the art to make and use the disclosure. The patentable
scope of the disclosure is defined by the claims, and may include
other examples that occur to those skilled in the art. Such other
examples are intended to be within the scope of the claims if they
have structural elements, components, or materials that do not
differ from the literal language of the claims, or if they include
equivalent structural elements, components, or materials with
insubstantial differences from the literal language of the claims.
The above examples are merely illustrative of various aspects of
the present disclosure, wherein equivalent alterations and/or
modifications will occur to others skilled in the art upon reading
and understanding this specification and the annexed drawings. In
particular regard to the various functions performed by the above
described components (assemblies, devices, systems, and the like),
the terms (including a reference to "means") used to describe such
components are intended to correspond, unless otherwise indicated,
to any component which performs the specified function of the
described component (i.e., that is functionally equivalent), even
though not structurally equivalent to the disclosed structure which
performs the function in the illustrated implementations of the
disclosure. In addition, although a particular feature of the
disclosure may have been illustrated and/or described with respect
to only one of several implementations, such feature may be
combined with one or more other features of the other
implementations as may be desired and advantageous for any given or
particular application. Also, to the extent that the terms
"including", includes", "having", "has", "with", or variants
thereof are used in the detailed description and/or in the claims,
such terms are intended to be inclusive in a manner similar to the
term "comprising. Moreover, this disclosure is intended to seek
protection for a combination of components and/or steps and a
combination of claims as originally presented for examination, as
well as seek potential protection for other combinations of
components and/or steps and combinations of claims during
prosecution.
* * * * *