U.S. patent application number 15/458564 was filed with the patent office on 2017-09-21 for foam compositions and uses thereof.
The applicant listed for this patent is NIKE, Inc.. Invention is credited to Hossein A. Baghdadi.
Application Number | 20170267846 15/458564 |
Document ID | / |
Family ID | 59848241 |
Filed Date | 2017-09-21 |
United States Patent
Application |
20170267846 |
Kind Code |
A1 |
Baghdadi; Hossein A. |
September 21, 2017 |
FOAM COMPOSITIONS AND USES THEREOF
Abstract
Components for articles of footwear and athletic equipment are
provided including a foam. A variety of foams and foam components
and compositions for forming the foams are provided. In some
aspects, the foams and components including the foams can have
exceptionally high energy return while also having improved
durability and softness. In particular, midsoles including the
foams are provided for use in an article of footwear. Methods of
making the compositions and foams are provided, as well as methods
of making an article of footwear including one of the foam
components. In some aspects, the foams and foam components can be
made by injection molding or injection molding followed by
compression molding.
Inventors: |
Baghdadi; Hossein A.;
(Portland, OR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NIKE, Inc. |
Beaverton |
OR |
US |
|
|
Family ID: |
59848241 |
Appl. No.: |
15/458564 |
Filed: |
March 14, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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62308694 |
Mar 15, 2016 |
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62329625 |
Apr 29, 2016 |
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62429912 |
Dec 5, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A43B 13/188 20130101;
C08J 2353/02 20130101; A43B 13/223 20130101; C08L 23/0815 20130101;
A43B 7/14 20130101; C08L 23/14 20130101; C08J 2423/08 20130101;
C08L 2205/03 20130101; A43B 7/144 20130101; A43B 1/10 20130101;
A43B 13/125 20130101; C08J 2323/08 20130101; C08J 2423/10 20130101;
A43B 13/04 20130101; A43B 13/16 20130101; C08J 2423/02 20130101;
C08L 23/0853 20130101; C08J 2201/026 20130101; A43B 5/06 20130101;
C08J 2207/00 20130101; C08J 2453/00 20130101; C08J 9/0061 20130101;
C08J 9/06 20130101; B29D 35/122 20130101; A43B 13/186 20130101;
C08J 2353/00 20130101; C08L 53/025 20130101; C08J 2331/04 20130101;
A43B 13/141 20130101; C08L 2205/035 20130101; C08L 23/0853
20130101; C08L 23/0815 20130101; C08L 53/00 20130101; C08L 53/025
20130101; C08L 23/14 20130101; C08L 23/14 20130101 |
International
Class: |
C08L 23/08 20060101
C08L023/08; A43B 13/18 20060101 A43B013/18; A43B 13/04 20060101
A43B013/04 |
Claims
1. A composition made by a process comprising crosslinking and
foaming a first composition, wherein the first composition
comprises: an A-B-A block copolymer, wherein each of the A blocks
comprise styrenic repeat units, the B block is a random copolymer
of ethylene and a first alpha-olefin having 3 to 8 carbon atoms,
and wherein the A-B-A-block copolymer comprises about 10% to about
40% of the A blocks by weight based upon an entire weight of the
A-B-A block copolymer; an olefinic block copolymer, wherein the
olefinic block copolymer is a copolymer of ethylene and a second
alpha-olefin having about 6 to 12 carbon atoms, and wherein the
olefinic block copolymer has one or more blocks rich in the
ethylene and one or more blocks rich in the second alpha-olefin;
and an alpha-olefin linking polymer, wherein the alpha-olefin
linking polymer is a copolymer of ethylene and a third alpha-olefin
having about 3 to 18 carbon atoms, and wherein the alpha-olefin
linking polymer has an alpha-olefin monomer content of about 15% to
about 40% by weight based upon an entire weight of the alpha-olefin
linking polymer.
2. The composition according to claim 1, wherein the alpha-olefin
linking polymer has an alpha-olefin monomer content of about 15% to
about 40% by weight based upon an entire weight of the alpha-olefin
linking polymer.
3. The composition according to claim 1, wherein each of the A
blocks consists essentially of polystyrene.
4. The composition according to claim 3, wherein the B block
consists essentially of a copolymer of ethylene and octene.
5. The composition according to claim 3, wherein the B block
consists essentially of a copolymer of ethylene and butadiene.
6. The composition according to claim 1, wherein the first
composition comprises about 5 parts by weight to about 15 parts by
weight of the A-B-A block copolymer, about 10 parts by weight to
about 20 parts by weight of the olefinic block copolymer, and about
25 parts by weight to about 35 parts by weight of the alpha-olefin
linking polymers based upon an entire weight of the
composition.
7. The composition according to claim 1, wherein a ratio II of a
total parts by weight of the A-B-A block copolymer present in the
composition to a total parts by weight of the linking alpha-olefin
polymers present in the composition is from about 1.00 to about
5.00.
8. The composition according to claim 7, wherein the ratio II is
from about 1.50 to about 4.00.
9. The composition according to claim 1, wherein the process
comprises injection molding the pre-foam composition into an
injection mold and crosslinking the pre-foam composition in the
injection mold, and wherein the injection mold is at a temperature
from about 150.degree. C. to about 190.degree. C. during the
crosslinking.
10. The composition according to claim 1, wherein the composition
comprises a degree of crosslinking from about 50% to about 99%.
11. The composition according to claim 1, wherein the foam
composition has a specific density of about 0.08 to about 0.15.
12. The composition according to claim 1, wherein the composition
has an energy return from about 60% to about 85%.
13. The composition according to claim 1, wherein the composition
has a split tear of about 2.5 kg/cm to about 3.5 kg/cm.
14. The composition according to claim 1, wherein the composition
has an Asker C hardness of about 40 to 60 C.
15. A composition made by a process comprising crosslinking and
foaming a first composition, wherein the first composition
comprises: a partially hydrogenated thermoplastic elastomeric block
copolymer, the partially hydrogenated thermoplastic elastomeric
block copolymer comprising: one or more A blocks comprising
aromatic repeat units, one or more B blocks comprising aliphatic
repeat units, and one or more first ethylenically unsaturated
groups present on one or both of the aromatic repeat units and the
aliphatic repeat units; an olefinic block copolymer, wherein the
olefinic block copolymer is a copolymer of a first alpha-olefin and
a second alpha-olefin different from the first alpha-olefin, and
wherein the olefinic block copolymer comprising one or more second
ethylenically unsaturated groups; and an alpha-olefin linking
polymer, wherein the alpha-olefin linking polymer comprises one or
more aliphatic sidechains.
16. The composition according to claim 15, wherein the partially
hydrogenated thermoplastic elastomeric block copolymer comprises an
A-B block structure or an A-B-A block structure, wherein each of
the A blocks comprise one or more aromatic repeat units, and
wherein the B block is an aliphatic polymer block comprising the
one or more first ethylenically unsaturated units.
17. The composition according to claim 15, wherein the partially
hydrogenated thermoplastic elastomeric block copolymer comprises
about 10% to about 40% of the A block by weight based upon an
entire weight of the partially hydrogenated thermoplastic
elastomeric block copolymer.
18. The composition according to claim 15, wherein a ratio II of a
total parts by weight of the partially hydrogenated thermoplastic
elastomeric block copolymer present in the composition to a total
parts by weight of the linking alpha-olefin polymers present in the
composition is from about 1.00 to about 5.00.
19. The composition according to claim 18, wherein the ratio II is
from about 1.50 to about 4.00.
20. The composition according to claim 15, further comprising an
ethylene-vinyl acetate copolymer having a vinyl acetate content of
about 10% to about 45% by weight based upon the weight of the
ethylene-vinyl acetate copolymer.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to, and the benefit of,
co-pending U.S. provisional application entitled "FOAM COMPOSITIONS
AND USES THEREOF" having Ser. No. 62/308,694 filed Mar. 15, 2016,
co-pending U.S. provisional application entitled "FOAM COMPOSITIONS
AND USES THEREOF" having Ser. No. 62/329,625 filed Apr. 29, 2016,
and co-pending U.S. provisional application entitled "FOAM
COMPOSITIONS AND USES THEREOF" having Ser. No. 62/429,912 filed
Dec. 5, 2016, the contents of which are each incorporated by
reference in their entirety.
TECHNICAL FIELD
[0002] The present disclosure generally relates to materials, and
in particular to materials for the footwear and related industries
and uses thereof.
BACKGROUND
[0003] Footwear design involves a variety of factors from the
aesthetic aspects, to the comfort and feel, to the performance and
durability. While footwear design and fashion may be rapidly
changing, the demand for increasing performance in the athletic
footwear market is unchanging. To balance these demands, footwear
designers employ a variety of materials and designs for the various
components that make up an article of footwear.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Further aspects of the present disclosure will be readily
appreciated upon review of the detailed description, described
below, when taken in conjunction with the accompanying
drawings.
[0005] FIG. 1 is an elevation view of an article of footwear with a
sole component according to an aspect of the invention.
[0006] FIG. 2 is an exploded view of the sole component of the
article of footwear of FIG. 1.
[0007] FIG. 3 is a plan view of the bottom of the sole component of
the article of footwear of FIG. 1.
[0008] FIG. 4 is a bottom view of an insert for use in a sole
component of an article of footwear.
[0009] FIG. 5 is a top view of the insert of FIG. 4 inserted in a
first portion to form a sole component.
DETAILED DESCRIPTION
[0010] New designs and materials for the footwear industry are
needed. In particular, there remains a need for improved foam
compositions, for example that can be used in the footwear industry
to provide improved cushion and energy return when used in a
midsole or other component for an article of footwear.
[0011] In various aspects, compositions are provided that can be
foamed, i.e. can be used to produce a foam composition. For
clarity, compositions that have not been foamed will, in some
instances be referred to as "pre-foam" compositions. Foam
compositions are also provided, e.g. compositions that have been
prepared by foaming a "pre-foam" composition described herein.
Articles of footwear, such as athletic shoes, and components
thereof are also provided including one or more of the foam
compositions. In particular, various aspects of the present
disclosure describe sole components for an article of footwear
having exceptionally high energy return. The sole components having
exceptionally high energy return can be made from foaming a
pre-foam composition described herein. Methods of making the
compositions and components made therefrom are also provided.
[0012] Before the present disclosure is described in greater
detail, it is to be understood that this disclosure is not limited
to particular aspects described, and as such may, of course, vary.
Other systems, methods, features, and advantages of foam
compositions and components thereof will be or become apparent to
one with skill in the art upon examination of the following
drawings and detailed description. It is intended that all such
additional systems, methods, features, and advantages be included
within this description, be within the scope of the present
disclosure, and be protected by the accompanying claims. It is also
to be understood that the terminology used herein is for the
purpose of describing particular aspects only, and is not intended
to be limiting. The skilled artisan will recognize many variants
and adaptations of the aspects described herein. These variants and
adaptations are intended to be included in the teachings of this
disclosure and to be encompassed by the claims herein.
[0013] Articles of Footwear
[0014] In various aspects, articles of footwear are provided. In
particular, articles of footwear are provided including one or more
components made entirely or partially from a foam mentioned above
and described in more detail below. The foams and components made
therefrom can have a range of desirable properties for footwear,
including softness, durability, and an exceptionally high energy
return. The articles of footwear can, in principal, include any
article of footwear. In various aspects, the article of footwear
can include a shoe, a boot, or a sandal.
[0015] The most common articles of footwear are shoes. Shoes can
include athletic shoes such as baseball shoes, basketball shoes,
soccer shoes, football shoes, running shoes, cross-trainer shoes,
cheerleading shoes, golf shoes, and the like. The shoes can, in
some aspects, be cleated. An exemplary article of footwear 10 is
shown in FIG. 1. While an athletic shoe is exemplified in FIG. 1,
it will be readily understood that some of the terminology employed
will also apply to other articles of footwear or to other styles of
shoe. Footwear 10 includes an upper 12 and a sole component 14
secured to upper 12. Sole component 14 can be be secured to upper
12 by adhesive or any other suitable means. As used herein, the
sole component 14 can be a monolithic component formed entirely of
the foam material as described herein, or a multi-component
assembly formed of a plurality of monolithic components, where at
least one of the monolithic components is formed entirely of the
foam material as described herein. Footwear 10 has a medial, or
inner, side 16 and a lateral, or outer, side 18.
[0016] The upper, in some aspects, is unformed until the point that
it is attached to the sole component. In some aspects, the upper is
a lasted upper. A "lasted upper," as used herein, refers to an
upper that is formed into the shoe shape prior to attachment to the
sole by one or more mechanical means. The lasted upper can include
a heel counter formed to shape the heel of the upper. The lasted
upper can include a strobel sock or a strobel board attached to the
upper, typically via a strobel stitch.
[0017] Sole component 14, which is generally disposed between the
foot of the wearer and the ground, provides attenuation of ground
reaction forces (i.e., imparting cushioning), traction, and may
control foot motions, such as pronation. As with conventional
articles of footwear, sole component 14 can include an insole (not
shown) located within upper 12. In some aspects, the sole component
is an insole or sockliner or is a multi-component assembly
including an insole or sockliner, can further include an insole or
sockliner located within the upper, where the insole or sockliner
is formed entirely or partially of a foam material described
herein. Articles of footwear described herein can include an insole
or sockliner formed entirely or partially of a foam material
described herein.
[0018] The most common components of shoes and other footwear can
be classified into one of three types of components: upper
components, lower components, and grindery components. Upper
components refer collectively to all of the components that are
stitched or otherwise joined together to form the upper. The
materials in the upper generally contribute to characteristics such
as breathability, conformability, weight, and suppleness or
softness. The lower components refer collectively to all of the
components that collectively form the lower. The lower can include,
for example, the outsole and midsole. The choice of outsole
materials and design will contribute, for instance, to the
durability, traction, as well as to the pressure distribution
during use. The midsole materials and design contribute to factors
such as the cushioning and support. Grindery components include all
of the additional components that can be attached to the upper,
lower, or both. Grindery components can include, for example,
eyelets, toe puffs, shanks, nails, laces, velcro, catches, backers,
linings, padding, heel backings, heel foxings, toe caps, etc.
[0019] For purposes of general reference, footwear 10 can be
divided into three general portions: a forefoot portion 20, a
midfoot portion 22, and a heel portion 24. Portions 20, 22, and 24
are not intended to demarcate precise areas of footwear 10. Rather,
portions 20, 22, and 24 are intended to represent general areas of
footwear 10 that provide a frame of reference during the following
discussion.
[0020] Unless otherwise stated, or otherwise clear from the context
below, directional terms used herein, such as rearwardly,
forwardly, top, bottom, inwardly, downwardly, upwardly, etc., refer
to directions relative to footwear 10 itself. Footwear is shown in
FIG. 1 to be disposed substantially horizontally, as it would be
positioned on a horizontal surface when worn by a wearer. However,
it is to be appreciated that footwear 10 need not be limited to
such an orientation. Thus, in FIG. 1, rearwardly is toward heel
portion 24, that is, to the right as seen in FIG. 1. Naturally,
forwardly is toward forefoot portion 20, that is, to the left as
seen in FIG. 1, and downwardly is toward the bottom of the page as
seen in FIG. 1. Top refers to elements toward the top of the page
as seen in FIG. 1, while bottom refers to elements toward the
bottom of the page as seen in FIG. 1. Inwardly is toward the center
of footwear 10, and outwardly is toward the outer peripheral edge
of footwear 10.
[0021] Unless otherwise stated, or otherwise clear from the context
below, directional terms used herein, such as rearwardly,
forwardly, top, bottom, inwardly, downwardly, upwardly, etc., refer
to directions relative to footwear 10 itself. Footwear is shown in
FIG. 1 to be disposed substantially horizontally, as it would be
positioned on a horizontal surface when worn by a wearer. However,
it is to be appreciated that footwear 10 need not be limited to
such an orientation. Thus, in FIG. 1, rearwardly is toward heel
portion 24, that is, to the right as seen in FIG. 1. Naturally,
forwardly is toward forefoot portion 20, that is, to the left as
seen in FIG. 1, and downwardly is toward the bottom of the page as
seen in FIG. 1. Top refers to elements toward the top of the page
as seen in FIG. 1, while bottom refers to elements toward the
bottom of the page as seen in FIG. 1. Inwardly is toward the center
of footwear 10, and outwardly is toward the outer peripheral edge
of footwear 10.
[0022] As can be seen in FIG. 2, sole component 14 consists of a
first portion 26 having an upper surface 27 with a recess 28 formed
therein. Upper surface 27 is secured to upper 12 with adhesive or
other suitable fastening means. A plurality of substantially
horizontal ribs 30 is formed on the exterior of first portion 26.
In certain aspects, ribs 30 extend from a central portion of
forefoot portion 20 on medial side 16 rearwardly along first
portion 26, around heel portion 24 and forwardly on lateral side 18
of first portion 26 to a central portion of forefoot portion
20.
[0023] First portion 26 provides the external traction surface of
sole component 14. In certain aspects it is to be appreciated that
a separate outsole component could be secured to the lower surface
of first portion 26.
[0024] Recess 28 extends from heel portion 24 to forefoot portion
20. In certain aspects, the rear surface 32 of recess 28 is curved
to substantially follow the contour of the rear of heel portion 24
and the front surface 34 of recess 28 extends transversely across
first portion 26.
[0025] An insert 36 is received in recess 28. Insert 36 has a
curved rear surface 38 to mate with curved rear surface 32 of
recess 28 and a transverse front surface 40 to mate with transverse
front surface 34 of recess 28. An upper surface 42 of insert 36 is
in contact with and secured to upper 12 with adhesive or other
suitable fastening means.
[0026] As seen best in FIG. 3, a ground engaging lower surface 44
of first portion 26 includes a plurality of projections 46. Each
projection 46 is surrounded by a groove 48. A plurality of
transverse slots 50 are formed in lower surface 44, extending
between adjacent projections 46. A longitudinal slot 52 extends
along lower surface 44 from heel portion 26 to forefoot portion
20.
[0027] As illustrated in FIG. 2, insert 36 can provide cushioning
or resiliency in the sole component. First portion 26 can provide
structure and support for insert 36. In such aspects, first portion
26 can be formed of a material of higher density and/or hardness as
compared to insert 36 such as, for example, non-foam materials
including rubber and thermoplastic polyurethane, as well as foam
materials. In certain aspects, insert 36 can be formed of a foam
material as disclosed herein.
[0028] FIGS. 4 and 5 show bottom and top views of an insert 60
which can be used in a sole component as described herein. Insert
60 is similar to insert 36, but as illustrated in FIGS. 4 and 5,
insert 60 is formed of two types of materials 62 and 64, where at
least one of the materials is a foam as disclosed herein. FIG. 4
shows a bottom view of insert 60, while FIG. 5 shows a top view of
insert 60 formed of two types of materials 62 and 64, with the
insert placed inside a first portion 66 to form a sole component
14. Inserts with more than two types of materials, at least one of
which is a foam as disclosed herein, can also be used. In the
example illustrated in FIGS. 4 and 5, a portion of a first material
62 can be used in the heel region of the insert, and a portion of a
second material 64 can be used in the toe region of the insert. A
higher density material can be used to support the heel region,
while a lower density material can be used to support the toe
region. For example, the density of the first material can be at
least 0.02 g/cm.sup.3 greater than the density of the second
material. The shape of the portions of the two materials 62 and 64
of the insert can be any suitable shape. For example, the heel
region can be in the shape of a wedge. Inserts formed of two types
of materials can be useful in running shoes, as well as in
basketball shoes.
[0029] While the compositions and foams described herein can be
used for making any of a variety of components for an article of
footwear, in particular aspects the components include a midsole,
an outsole, an insole, a tongue padding, a collar padding, and a
combination thereof. In some aspects, the component is a sole
component, such as a sole component 14 depicted in FIGS. 1-5, that
includes a foam described herein. In some aspects, the component is
an insert such as insert 36 or insert 60 depicted in FIGS. 4-5 that
includes a foam described herein. The sole components and inserts
for sole components can be made partially or entirely of a foam
described herein. Any portion of a sole component or an insert for
a sole component can be made of a foam described herein. For
example, first portion 26 of the sole component (optionally
including the ground engaging lower surface 44, such as the
plurality of projections 46 and/or the groove 48 surrounding the
projections), the entire insert 36, portions 62 or 64 of insert 60,
a separate outsole component, or any combination thereof, can
include a foam as described herein. The sole components and inserts
can be made by foaming a composition provided herein, for example
by injection molding or by injection molding followed by
compression molding as described herein. The foams and components
can demonstrate improved physical properties including one or more
of an enhanced energy return, and enhanced split tear, a decreased
specific density, or a combination thereof.
[0030] Split tear is an important physical property for a foam for
a component of an article of footwear or athletic equipment. In
some aspects, the foam or component can have a split tear value of
about 1.0 kg/cm to 4.5 kg/cm, about 1.6 kg/cm to 4.0 kg/cm, about
2.0 kg/cm to 4.0 kg/cm, about 2.0 kg/cm to 3.5 kg/cm, or about 2.5
kg/cm to 3.5 kg/cm. The split tear can be measured as described in
the examples below. In some aspects, the foam or component is
compression molded, and the compression molded foam or component
can have a split tear of about 0.08 kg/cm to 4.0 kg/cm, about 0.9
kg/cm to 3.0 kg/cm, about 1.0 to 2.0 kg/cm, about 1.0 kg/cm to 1.5
kg/cm, or about 2 kg/cm. In some aspects, the foam or component is
injection molded, and the foam or component can have a split tear
of about 0.07 kg/cm to 2.0 kg/cm, or about 0.8 kg/cm to 1.5 kg/cm,
or about 0.9 to 1.2 kg/cm, about 1.5 kg/cm to 2.2 kg/cm.
[0031] The energy return, a measure of the percentage of energy the
foam or component returns when compressed, is an important physical
property. This is especially true for running and other athletic
shoes. In some aspects, the foams and components provided herein
have an energy return of about 60% to 90%, about 60% to 85%, about
65% to 85%, or about 70% to 85%. In some aspects, the foam or
component is compression molded and can have an energy return of
about 60% to 95% (e.g., about 60% to 85%; about 65% to 80%; about
65% to 75%; about 70% to 80%; or about 75% to 80%; about 75% to
85%; about 80% to 95%; or about 85% to 95%). The energy return can
be measured as described in the examples below.
[0032] The foams and components can be lightweight. In some
aspects, the foams and components can have a specific density of
about 0.05 to 0.25, about 0.05 to 0.2, about 0.05 to 0.15, about
0.08 to 0.15, about 0.08 to 0.20, about 0.08 to 0.25, or about 0.1
to 0.15. In some aspects the foam or component is compression
molded and can have a specific density of about 0.15 to 0.3, about
0.2 to 0.3, or about 0.15 to 0.25.
[0033] In some examples, the process for making the foams and
components of the various examples described herein further
includes compression molding the foam to give a compression molded
foam or a compression molded component. In some aspects,
compression molding foamed preforms formed from the foam
compositions of the present disclosure can produce compression
molded foam components having physical properties which make these
components particularly advantageous for use in articles of
footwear and athletic equipment. For example, the physical
properties of these compression molded foam components make them
particularly useful for use as cushioning elements, such as
midsoles.
[0034] In some aspects, the resiliency and/or energy return of the
compression molded foam or compression molded component can be
significantly greater than the resiliency and/or energy return of
the otherwise same foam preform used to make the compression molded
foam component. While compression molded foam components formed
from preforms foamed using other blowing methods sometimes have
greater resiliency and/or energy return than their preforms, an
even greater increase in resiliency and/or energy return can be
achieved when compression molding foam preforms that were foamed
using an impregnation process utilizing a physical blowing agent,
as described herein. The resiliency and/or energy return of the
compression molded foam component can be at least at least 6
percentage points, or at least 7 percentage points, or at least 8
percentage points, or at least 9 percentage points, or at least 10
percentage points, or at least 12 percentage points greater than
the resiliency and/or energy return of the foam preform used to
make the compression molded foam component. In particular examples,
the resiliency and/or energy return of the compression molded foam
component is at least 9 percentage points greater than the
resiliency and/or energy return of the foam preform used for make
the compression molded foam component.
[0035] This greater increase in the resiliency and/or energy return
of the compression molded foam component can thus result in
components having higher resiliency and/or energy return than would
be possible using foam preforms made using other blowing methods.
Using the blowing methods described herein, it has been found that
it is possible to produce compression molded foam components having
higher than usual resiliencies while using materials and methods
which are cost-effective for use in consumer goods such as articles
of footwear and athletic equipment. The resiliency and/or energy
return of the compression molded foam component can be greater than
45%, or greater than 50%, or greater than 55%, or greater than 60%,
or greater than 65%. For example, the resiliency and/or energy
return of the compression molded foam component can be from 45% to
95%, or from 50% to 90%, or from 55% to 90%, or from 60% to 80%, or
from 50% to 85%, or from 55% to 75%, or from 60% to 75%.
Compression molded foam components having resiliencies greater than
45%, or 50%, or 55%, or 60%, or 65%, can be particularly
advantageous for use in articles of footwear. Additionally or in
combination, the resiliency and/or energy return of the foam
preform can be less than 75%, or less than 70%, or less than 65%,
or less than 60%. For example, the resiliency and/or energy return
of the foam preform can be from 40% to 80%, or from 55% to 75%, or
from 50% to 70% or from 65% to 80%.
[0036] In particular examples, the resiliency and/or energy return
of the compression molded foam component can be at least at least 6
percentage points, or at least 7 percentage points, or at least 8
percentage points, or at least 9 percentage points, or at least 10
percentage points, or at least 12 percentage points greater than
the resiliency and/or energy return of the foam preform used to
make the compression molded foam component when the compression
molded foam component has a resiliency and/or energy return greater
than 45%, or greater than 50%, or greater than 55%, or greater than
60%, or greater than 65%.
[0037] Several methods of measuring resiliency and/or energy return
of foams (e.g., foam preforms and foam components) exist in the
art. One method of measuring resiliency of foams is based on ASTM D
2632-92, which is a test for solid rubber materials. For use with
foams, the test sample is prepared as described in ASTM D2632-92,
but uses a sample of foam in place of the sample of solid rubber.
This test uses a plunger which is dropped from a height onto a test
sample while being guided by a vertical rod. The drop height is
divided into 100 equal parts, and the height to which the plunger
rebounds is measured using this 100 part scale, to determine the
resiliency of the sample. Alternative methods which use a ball of
standard weight dropped onto a sample, and which measure the
rebound height of the ball to determine the resiliency of the
sample can also be used.
[0038] The specific gravity of a foam is also an important physical
property to consider when using a foam for a component of an
article of footwear or athletic equipment. The foams and components
of the present disclosure can have a specific gravity of from 0.02
g/cm.sup.3 to 0.22 g/cm.sup.3, or of from 0.03 g/cm.sup.3 to 0.12
g/cm.sup.3, or of from 0.04 g/cm.sup.3 to 0.10 g/cm.sup.3, or from
0.11 g/cm.sup.3 to 0.12 g/cm.sup.3, or from 0.10 g/cm.sup.3 to 0.12
g/cm.sup.3, from 0.15 g/cm.sup.3 to 0.2 g/cm.sup.3; 0.15 g/cm.sup.3
to 0.30 g/cm.sup.3. Alternatively or in addition, the foam preform
can have a specific gravity of from 0.01 g/cm.sup.3 to 0.10
g/cm.sup.3, or of from 0.02 g/cm.sup.3 to 0.08 g/cm.sup.3, or of
from 0.03 g/cm.sup.3 to 0.06 g/cm.sup.3; 0.08 g/cm.sup.3 to 0.15
g/cm.sup.3; or from 0.10 g/cm.sup.3 to 0.12 g/cm.sup.3. For
example, the specific gravity of the compression molded foam
component can be from or from 0.15 g/cm.sup.3 to 0.2 g/cm.sup.3,
and the specific gravity of the foam preform can be from 0.10
g/cm.sup.3 to 0.12 g/cm.sup.3. The foam or component can be
compression molded.
[0039] In particular examples, the resiliency and/or energy return
of the compression molded foam component can be at least at least 6
percentage points, or at least 7 percentage points, or at least 8
percentage points, or at least 9 percentage points, or at least 10
percentage points, or at least 12 percentage points greater than
the resiliency and/or energy return of the foam preform used to
make the compression molded foam component when the compression
molded foam component has a resiliency and/or energy return greater
than 45%, or greater than 50%, or greater than 55%, or greater than
60%, or greater than 65%, and the compression molded foam can have
a specific gravity of from 0.02 g/cm.sup.3 to 0.15 g/cm.sup.3, or
of from 0.03 g/cm.sup.3 to 0.12 g/cm.sup.3, or of from 0.04
g/cm.sup.3 to 0.10 g/cm.sup.3 or from 0.11 g/cm.sup.3 to 0.12
g/cm.sup.3, from 0.15 g/cm.sup.3 to 0.2 g/cm.sup.3; or 0.15
g/cm.sup.3 to 0.30 g/cm.sup.3.
[0040] The specific gravity of the foam or component can be
determined by testing at least 3 representative samples taken from
a foam preform or compression molded foam component (e.g., a 2
inch.times.2 inch sample or a 1 inch.times.1 inch sample), or at
least 3 entire foam preforms or compression molded foam components.
Using a balance with appropriate accuracy for the weight of the
sample, the weight of each sample is determined both in air and
when the sample is completely submerged in distilled water at a
temperature of 22.degree. C..+-.2.degree. C., after removing any
air bubbles adhered to the surface of the foam sample weighing. The
specific gravity (S.G.) is then calculated by taking the weight of
the sample in water and subtracting that from the weight of the
sample in air, and this value is then divided into the weight of
the sample in air, where all the weights are weights in grams.
[0041] Compression set of a foam is another important physical
property for a foam used as a component of an article of footwear
or athletic equipment. In accordance with the present disclosure,
the compression molded foam or compression molded component can
have a compression set of from 40% to 100%. For example, the
compression set can be from 45% to 90%, or from 40% to 80%, or from
50% to 75%.
[0042] Compression set can be measured by preparing a sample of a
standard thickness (e.g., 10 mm) of a foam preform. Components
having a thickness less than the standard can be stacked to make a
sample having the standard thickness. The sample is loaded into a
metal compression plate and compressed to a height of 50% of the
original thickness (e.g., 5 mm). The sample is placed in a
50.degree. C. oven on its side for 6 hours. At the end of the 6
hours, the sample is removed from the oven and from the metal
compression plate, and allowed to cool for 30 minutes. Once cooled,
the thickness of the sample is measured. The percent compression
set (C.S.) is calculated by (a) subtracting the final sample
thickness from the original sample thickness, and (b) subtracting
the 50% compressed thickness from the original sample thickness,
(c) dividing (a) by (b), and (d) multiplying the result by 100 to
obtain the percent compression set (where all thicknesses are
measured in millimeters).
[0043] Durometer is another important physical property of a foam
or component that is to be used in an article of footwear or
athletic equipment. In accordance with the present disclosure, the
compression molded foam or component can have a durometer of at
least 20 Asker C, or at least 30 Asker C, or at least 40 Asker C,
or at least 50 Asker C. For example, the durometer of the
compression molded foam or compression molded component can have a
durometer of from 20 Asker C to 70 Asker C, or of from 20 Asker C
to 40 Asker C, or from 30 Asker C to 35 Asker C, or of from 25
Asker C to 65 Asker C, or of from 30 Asker C to 50 Asker C, or of
from 40 Asker C to 70 Asker C, or of from 35 Asker C to 55 Asker C,
or from 50 Asker C to 65 Asker C. The foam preform can have a
durometer of less than 40 Asker C, or less than 30 Asker C, or less
than 20 Asker C. For example, the durometer of the foam preform can
be from 15 Asker C to 50 Asker C, or from 20 Asker C to 50 Asker C,
or from 20 Asker C to 40 Asker C, or from 20 Asker C to 30 Asker C.
The durometer can be measured on a flat area of foam, e.g., at
least 6 mm thick using an Asker C durometer.
[0044] In particular examples, the resiliency and/or energy return
of the compression molded foam component can be at least at least 6
percentage points, or at least 7 percentage points, or at least 8
percentage points, or at least 9 percentage points, or at least 10
percentage points, or at least 12 percentage points greater than
the resiliency and/or energy return of the foam preform used to
make the compression molded foam component when the compression
molded foam component has a resiliency and/or energy return greater
than 45%, or greater than 50%, or greater than 55%, or greater than
60%, or greater than 65%, and the compression molded foam component
can have a of at least 20 Asker C, or at least 30 Asker C, or at
least 40 Asker C, or at least 50 Asker C. In addition, the
compression molded foam can have a specific gravity of from 0.02
g/cm.sup.3 to 0.15 g/cm.sup.3, or of from 0.03 g/cm.sup.3 to 0.12
g/cm.sup.3, or of from 0.04 g/cm.sup.3 to 0.10 g/cm.sup.3, or from
0.11 g/cm.sup.3 to 0.12 g/cm.sup.3 from 0.15 g/cm.sup.3 to 0.2
g/cm.sup.3; or 0.15 g/cm.sup.3 to 0.30 g/cm.sup.3.
[0045] Split tear is another important physical property for a foam
or a component used in an article of footwear or athletic
equipment. In accordance with the present disclosure, the
compression molded foam or component can have a split tear of from
0.08 kg/cm to 4.0 kg/cm, or of from 0.9 kg/cm to 3.0 kg/cm, or of
from 1.0 to 2.0 kg/cm, or of from 1.0 kg/cm to 1.5 kg/cm, or of
about 2 kg/cm. Alternatively or in addition, the foam preform can
have a split tear of from 0.07 kg/cm to 2.0 kg/cm, or of from 0.8
kg/cm to 1.5 kg/cm, or of from 0.9 to 1.2 kg/cm, or from about 1.5
kg/cm to about 2.2 kg/cm.
[0046] Split tear for foam preforms and compression molded foam
components can be measured using ASTM D3574-95. Although this
method is directed to bonded and molded urethane foams, it can be
used on any foam material in accordance with the present
disclosure. A sample of foam having a thickness of 10 mm.+-.1 mm.
If the foam preform or compression molded foam component has an
outer skin, the outer skin should not be present on the test
sample. A 3 cm long cut is placed in the center of one end of the
specimen, and marked in five successive 2 cm portions along the
edge of the sample. The sample is tested as described in ASTM
D3574-95.
[0047] The tear strength of the compression molded foam component
can range from 4 kg/cm to 10 kg/cm.
[0048] The tensile strength of the foam is another important
physical characteristic. The foam or component can have a tensile
strength of from 5 kg/cm.sup.2 to 25 kg/cm.sup.2, or of from 10
kg/cm.sup.2 to 23 kg/cm.sup.2, or of from 15 kg/cm.sup.2 to 22
kg/cm.sup.2. The tensile strength can be measured on a die cut
sample of the foam in the shape of a dumbbell of a standard size
such as a 2.5 cm in width by 11.5 cm in length, with a minimum
thickness of 3 to 4 mm. The dumbbell follows the shape described in
ASTM D412, die C. The sample is loaded symmetrically into and
tested using a long travel extensometer such as the Instron
2603-080 which allows for a minimum of 1000% strain with a gauge
length of 25 mm and a resolution of at least 0.1 mm. The tensile
value at the failure point of the sample (the point during testing
when the load value initially drops) is recorded. The foam or
component can be compression molded.
[0049] Another physical property to consider when determining
whether or not a foam is suitable for use as a component of an
article of footwear or athletic equipment is its 300% elongation.
The compression molded foam or component can have an elongation of
at least 125 kg/cm.sup.2, or at least 150 kg/cm.sup.2.
[0050] Some examples described herein are directed to a foam
article (e.g., articles used to make at least portions of footwear
or athletic equipment) made by a process/method comprising: forming
a pre-foam composition comprising a polymer comprising styrene
repeating units and non-styrenic repeating units; and a
C.sub.4-C.sub.100 unsaturated olefin; crosslinking the polymer
comprising styrene repeating units and non-styrenic repeating units
and the C.sub.4-C.sub.100 unsaturated olefin olefin block copolymer
of the pre-foam composition, forming a crosslinked pre-foam
composition; and blowing the pre-foam composition, the crosslinked
pre-foam composition, or blowing both the pre-foam composition and
the crosslinked pre-foam composition, to give a foam article. In
some examples, the cross-linking and the blowing can occur
substantially simultaneously. In some examples, the process for
forming foam articles further comprises injection molding the
pre-foam composition, and the crosslinking occurs during the
injection molding. In some examples, the crosslinked composition,
or both the pre-foam composition and the crosslinked composition
are blown in a mold. In some examples, the crosslinking occurs
during the injection molding (e.g., the crosslinking occurs
substantially in the mold).
[0051] In some examples, the foam articles of the various examples
described herein can further comprise at least one ethylene vinyl
acetate copolymer and/or at least one olefin block copolymer, as
each of the terms is defined herein. The component, such as the
midsole, can have a variety of beneficial properties.
[0052] It has been found that, for many examples, the resiliency
and/or energy return (also referred to as energy return) of the
compression molded foam article can be significantly greater than
the resiliency and/or energy return of the foam article used to
make the compression molded foam article. While compression molded
foam articles formed using other blowing methods sometimes have
greater resiliency and/or energy return than the corresponding foam
article, an even greater increase in resiliency and/or energy
return can be achieved when compression molding foam articles that
were foamed using an impregnation process utilizing a physical
blowing agent, as described herein. The resiliency and/or energy
return of the compression molded foam article can be at least at
least 6 percentage points, or at least 7 percentage points, or at
least 8 percentage points, or at least 9 percentage points, or at
least 10 percentage points, or at least 12 percentage points
greater than the resiliency and/or energy return of the foam
article used to make the compression molded foam article. In
particular examples, the resiliency and/or energy return of the
compression molded foam article is at least 9 percentage points
greater than the resiliency and/or energy return of the foam
article used for make the compression molded foam article.
[0053] This greater increase in the resiliency and/or energy return
of the compression molded foam article can thus result in
components having higher resiliency and/or energy return than would
be possible using foam articles made using other blowing methods.
Using the blowing methods described herein, it has been found that
it is possible to produce compression molded foam articles having
higher than usual resiliencies while using materials and methods
which are cost-effective for use in consumer goods such as articles
of footwear and athletic equipment. The resiliency and/or energy
return of the compression molded foam article can be greater than
45%, or greater than 50%, or greater than 55%, or greater than 60%,
or greater than 65%. For example, the resiliency and/or energy
return of the compression molded foam article can be from 45% to
95%, or from 50% to 90%, or from 55% to 90%, or from 60% to 80%, or
from 50% to 85%, or from 55% to 75%, or from 60% to 75%.
Compression molded foam articles having resiliencies greater than
45%, or 50%, or 55%, or 60%, or 65%, can be particularly
advantageous for use in articles of footwear. Additionally or in
combination, the resiliency and/or energy return of the foam
article can be less than 75%, or less than 70%, or less than 65%,
or less than 60%. For example, the resiliency and/or energy return
of the foam article can be from 40% to 80%, or from 55% to 75%, or
from 50% to 70% or from 65% to 80%.
[0054] In particular examples, the resiliency and/or energy return
of the compression molded foam article can be at least at least 6
percentage points, or at least 7 percentage points, or at least 8
percentage points, or at least 9 percentage points, or at least 10
percentage points, or at least 12 percentage points greater than
the resiliency and/or energy return of the foam article used to
make the compression molded foam article when the compression
molded foam article has a resiliency and/or energy return greater
than 45%, or greater than 50%, or greater than 55%, or greater than
60%, or greater than 65%.
[0055] The specific gravity of a foam article is also an important
physical property to consider when using a foam for a component of
an article of footwear or athletic equipment. The compression
molded foam articles of the present disclosure can have a specific
gravity of from 0.02 g/cm.sup.3 to 0.22 g/cm.sup.3, or of from 0.03
g/cm.sup.3 to 0.12 g/cm.sup.3, or of from 0.04 g/cm.sup.3 to 0.10
g/cm.sup.3, or from 0.11 g/cm.sup.3 to 0.12 g/cm.sup.3, or from
0.10 g/cm.sup.3 to 0.12 g/cm.sup.3, from 0.15 g/cm.sup.3 to 0.2
g/cm.sup.3; 0.15 g/cm.sup.3 to 0.30 g/cm.sup.3. Alternatively or in
addition, the foam article can have a specific gravity of from 0.01
g/cm.sup.3 to 0.10 g/cm.sup.3, or of from 0.02 g/cm.sup.3 to 0.08
g/cm.sup.3, or of from 0.03 g/cm.sup.3 to 0.06 g/cm.sup.3; 0.08
g/cm.sup.3 to 0.15 g/cm.sup.3; or from 0.10 g/cm.sup.3 to 0.12
g/cm.sup.3. For example, the specific gravity of the compression
molded foam article can be from or from 0.15 g/cm.sup.3 to 0.2
g/cm.sup.3, and the specific gravity of the foam article can be
from 0.10 g/cm.sup.3 to 0.12 g/cm.sup.3.
[0056] In particular examples, the resiliency and/or energy return
of the compression molded foam article can be at least at least 6
percentage points, or at least 7 percentage points, or at least 8
percentage points, or at least 9 percentage points, or at least 10
percentage points, or at least 12 percentage points greater than
the resiliency and/or energy return of the foam article used to
make the compression molded foam article when the compression
molded foam article has a resiliency and/or energy return greater
than 45%, or greater than 50%, or greater than 55%, or greater than
60%, or greater than 65%, and the compression molded foam article
can have a specific gravity of from 0.02 g/cm.sup.3 to 0.15
g/cm.sup.3, or of from 0.03 g/cm.sup.3 to 0.12 g/cm.sup.3, or of
from 0.04 g/cm.sup.3 to 0.10 g/cm.sup.3, or from 0.11 g/cm.sup.3 to
0.12 g/cm.sup.3 from 0.15 g/cm.sup.3 to 0.2 g/cm.sup.3; or 0.15
g/cm.sup.3 to 0.30 g/cm.sup.3.
[0057] Compression set of a foam article is another important
physical property for a foam used as a component of an article of
footwear or athletic equipment. In accordance with the present
disclosure, the compression molded foam article can have a
compression set of from 40% to 100%. For example, the compression
set can be from 45% to 90%, or from 40% to 80%, or from 50% to
75%.
[0058] Durometer is another important physical property of a foam
article used as an article of footwear or athletic equipment. In
accordance with the present disclosure, the compression molded foam
article can have a durometer of at least 20 Asker C, or at least 30
Asker C, or at least 40 Asker C, or at least 50 Asker C. For
example, the durometer of the compression molded foam article can
have a durometer of from 20 Asker C to 70 Asker C, or of from 20
Asker C to 40 Asker C, or from 30 Asker C to 35 Asker C, or of from
25 Asker C to 65 Asker C, or of from 30 Asker C to 50 Asker C, or
of from 40 Asker C to 70 Asker C, or of from 35 Asker C to 55 Asker
C, or from 50 Asker C to 65 Asker C. The foam article can have a
durometer of less than 40 Asker C, or less than 30 Asker C, or less
than 20 Asker C. For example, the durometer of the foam preform can
be from 15 Asker C to 50 Asker C, or from 20 Asker C to 50 Asker C,
or from 20 Asker C to 40 Asker C, or from 20 Asker C to 30 Asker C.
The durometer can be measured on a flat area of foam, e.g., at
least 6 mm thick using an Asker C durometer.
[0059] In particular examples, the resiliency and/or energy return
of the compression molded foam article can be at least at least 6
percentage points, or at least 7 percentage points, or at least 8
percentage points, or at least 9 percentage points, or at least 10
percentage points, or at least 12 percentage points greater than
the resiliency and/or energy return of the foam article used to
make the compression molded foam article when the compression
molded foam article has a resiliency and/or energy return greater
than 45%, or greater than 50%, or greater than 55%, or greater than
60%, or greater than 65%, and the compression molded foam article
can have a of at least 20 Asker C, or at least 30 Asker C, or at
least 40 Asker C, or at least 50 Asker C. In addition, the
compression molded foam article can have a specific gravity of from
0.02 g/cm.sup.3 to 0.15 g/cm.sup.3, or of from 0.03 g/cm.sup.3 to
0.12 g/cm.sup.3, or of from 0.04 g/cm.sup.3 to 0.10 g/cm.sup.3, or
from 0.11 g/cm.sup.3 to 0.12 g/cm.sup.3 from 0.15 g/cm.sup.3 to 0.2
g/cm.sup.3; or 0.15 g/cm.sup.3 to 0.30 g/cm.sup.3.
[0060] The tear strength of the compression molded foam or article
can range from 4 kg/cm to 10 kg/cm. The tensile strength of the
foam or article is another important physical characteristic. The
compression molded foam article can have a tensile strength of from
5 kg/cm.sup.2 to 25 kg/cm.sup.2, or of from 10 kg/cm.sup.2 to 23
kg/cm.sup.2, or of from 15 kg/cm.sup.2 to 22 kg/cm.sup.2.
[0061] Another physical property to consider when determining
whether or not a foam article is suitable for use as a component of
an article of footwear or athletic equipment is its 300%
elongation. The compression molded foam article can have an
elongation of at least 125 kg/cm.sup.2, or at least 150
kg/cm.sup.2.
[0062] Various examples include methods of manufacturing an article
of footwear or components for an article of footwear. In some
examples, the methods of manufacturing an article of footwear
include blowing a composition described herein to give a foam
article; compression molding the foam article to make a compression
molded component for an article of footwear. The component can be a
midsole, and the method can include providing an upper and an
outsole for an article of footwear; and combining the compression
molded midsole, the upper, and the outsole to make an article of
footwear. In some examples, the method of manufacturing the article
of footwear includes combining a compression molded foam article,
an upper, and an outsole to make an article of footwear.
[0063] In some aspects, the present disclosure is directed to a
compression molded foam, and to a method of forming compression
molded foam for, among other applications, articles of footwear or
athletic equipment. In some examples, the method can be a process
comprising providing (e.g., preparing) a foam preform and then
compression molding the foam preform to form a compression molded
foam.
[0064] The present inventors have recognized, among other things,
that the compression molded foam of the various examples described
herein has improved physical characteristics, such as, for example,
improved resiliency and/or energy return.
[0065] In some examples, one step of the method comprises providing
(e.g., preparing or obtaining) a pre-foam composition as disclosed
herein. For example, the pre-foam composition can be prepared using
any method known in the art, including using a suitable kneader, a
suitable single-screw or a suitable twin-screw extruder. An
extruder (e.g., single or twin screw) can be used to provide a
pre-foam composition. The extruder can have a motor to turn a screw
inside the extruder. Screw may be a single screw or twin screws
made of individual elements of various sizes and pitches
appropriate for mixing or kneading the specific materials used. In
some examples, the extruder has a twin screw.
[0066] The various components that make up the pre-foam
compositions of the various examples described herein (e.g., a
polymer comprising styrene repeating units and non-styrenic
repeating units; a C.sub.4-C.sub.100 unsaturated olefin; and
optionally one or more additional components selected from an
ethylene vinyl acetate copolymer; an olefin block copolymer;
blowing agent; a crosslinking agent, and any combination thereof)
are added into the extruder through a port. In some examples, the
pre-foam compositions of the various examples described herein can
be at least partially crosslinked at a first crosslinking
temperature in, e.g., section of extruder to form a crosslinked
pre-foam composition (e.g., at least partially crosslinked pre-foam
composition), which, in some examples, may be a thermoplastic
crosslinked pre-foam composition. Various other components (e.g.,
pigments, fillers, and blowing agents) can be added via a port into
the extruder and mixed or kneaded with the pre-foam compositions
and/or the crosslinked pre-foam composition (e.g., at least
partially crosslinked pre-foam composition).
[0067] The various components that make up the pre-foam
compositions of the various examples described herein may be added
as a melt or as appropriately-sized solid particles, for example
chips or pellets, that are melted in section as they are mixed or
kneaded with, e.g., the crosslinked pre-foam composition (e.g., at
least partially crosslinked pre-foam composition).
[0068] The contents of the extruder or mixer may be heated to,
achieve, among other things, crosslinking of the pre-foam
compositions to give a crosslinked pre-foam composition (e.g., at
least partially crosslinked pre-foam composition). In other
examples, the heating may trigger foaming (i.e., blowing) (e.g.,
via triggering a chemical blowing agent), thereby converting the
crosslinked pre-foam composition (e.g., at least partially
crosslinked pre-foam composition) to a foam composition that is
sufficiently thermoplastic to be extruded or injected into a mold
from the extruder 10. Alternatively, the crosslinked pre-foam
composition (e.g., at least partially crosslinked pre-foam
composition) can be foamed in the extruder using a physical blowing
agent. And, in some examples, a chemical blowing agent can also be
present, such that, when there is heating, the heating can trigger
the chemical blowing agent.
[0069] In some examples, the pre-foam compositions may be added as
a melt at a temperature close to or at the crosslinking temperature
such that crosslinking can occur, but at a temperature that is
sufficiently below the temperature that would trigger blowing. The
temperature of the extruder can then be increased to a temperature
close to or at the triggering temperature of a chemical blowing
agent, thereby giving a foam composition.
[0070] The extent to which the pre-foam compositions is crosslinked
to give a crosslinked pre-foam composition (e.g., at least
partially crosslinked pre-foam composition) can be controlled so
that the crosslinked pre-foam composition (e.g., at least partially
crosslinked pre-foam composition) remains thermoplastic and can be
mixed with various other components (e.g., pigments, fillers, and
blowing agents) if necessary. This can be accomplished in various
ways, for instance by controlling the amount of time for
crosslinking; by controlling the crosslinking temperature; by
causing a temperature reduction at a desired point of crosslinking
to stop or slow further crosslinking; or by a combination of these.
For example, the amount of time for crosslinking can be controlled
by controlling screw speed, by locating port 8 closer to or further
from port 6, or by a combination of these.
[0071] In some examples, as the crosslinking density increases, the
crosslinked pre-foam composition (e.g., at least partially
crosslinked pre-foam composition) can form phase separated domains,
wherein, for example, the styrenic segments of the crosslinked
polymer comprising styrene repeating units and non-styrenic
repeating units phase separate into predominately styrene-rich
domains.
[0072] A crosslinked pre-foam composition (e.g., at least partially
crosslinked pre-foam composition) or a foam composition, each of
which is sufficiently thermoplastic to be extruded or injected into
a mold from the extruder, is extruded at an end of the extruded
opposite the motor. In some examples, a vacuum port may be used to
remove volatiles, for example water, volatile organic liquids that
may have been introduced as solvents with some materials,
crosslinking reaction by-products or blowing agent by-products. The
extrudate may be shaped by being extruded through a die (not
shown). For example, the extrudate (e.g., crosslinked pre-foam
composition or foam composition) may be extruded in the form of
strands that are then pelletized, in the form of a tube, or in the
form of a sheet. The pelletization can be conducted using a cooled
die. Additionally or alternatively, the pelletization can be
performed under water, thus cooling the resulting pellets as they
exited the pelletization die.
[0073] In some examples, the foam preforms of the various examples
described herein are obtained by blowing the pre-foam composition,
the crosslinked composition, or both the pre-foam composition and
the crosslinked composition by about 150% to about 240% (e.g., from
about 150% to about 220%; about 150% to about 200%, about 175% to
about 225%, about 180% to about 230% or about 160% to about 240%)
in at least one dimension (e.g., the vertical dimension) using a
blowing agent.
[0074] In some examples, the foam preforms of the various examples
described herein are made using a process that involves
impregnating a pre-foam composition, a crosslinked pre-foam
composition or combinations thereof (e.g., at or above a softening
temperature of the pre-foam composition, crosslinked pre-foam
composition or combinations thereof) with a physical blowing agent
at a first concentration or first pressure.
[0075] As used herein, the term "impregnating" generally means
dissolving or suspending a physical blowing agent in a pre-foam
composition, a crosslinked pre-foam composition or combinations
thereof. The impregnated pre-foam composition, crosslinked pre-foam
composition or combinations thereof can then be foamed, or can be
cooled (when applicable) and re-softened (when applicable) for
blowing at a later time.
[0076] In some instances, the impregnated pre-foam composition,
crosslinked pre-foam composition or combinations thereof is foamed
by reducing the concentration or pressure of the physical blowing
agent. The reduction in concentration of the physical blowing agent
can release additional amounts (e.g., to create a secondary
expansion of an originally-formed microcell in the pre-foam
composition, crosslinked pre-foam composition or combinations
thereof) of the impregnated physical blowing agent from the
pre-foam composition, crosslinked pre-foam composition or
combinations thereof, to further blow the pre-foam composition,
crosslinked pre-foam composition or combinations thereof, forming a
foam composition (e.g., a foam composition having a closed-cell
structure).
[0077] In addition to injection molding, the pre-foam compositions
of the present disclosure can be foamed and optionally molded using
various processes known in the art. For example, the pre-foam
compositions can be used to form slab foam, particulate (e.g.,
bead) foams of various shapes and sizes, etc. These various forms
of foam can then be used in different ways. For example, slab foam
can be used directly as a finished foam article, can be shaped
(e.g., cut or trimmed) to form a finished foam article, or can be
compression molded to form a finished foam article. The foams can
be subjected to annealing processes as part of forming the finished
foam article. Pellets of the pre-foam compositions can be used to
form individual particulate foams, or can be foamed and molded to
form unitary molded foam articles composed of individual portions
of foam affixed to each other.
[0078] The foam compositions of the various examples described
herein (e.g., foam preforms) may be further shaped or molded by any
of the methods known for forming articles from thermoplastic
materials.
[0079] Another step of the method for forming compression molded
foam includes providing a foam preform that has been foamed using
any suitable blowing process (e.g., blowing using a physical and/or
chemical blowing agent), and then compression molding the foam
preform to form a compression molded foam.
[0080] In some examples, the foam preform is prepared by a process
comprising (i) softening a pre-foam composition, a crosslinked
pre-foam composition or combinations thereof (e.g., by heating at a
first temperature at or above a softening temperature of the
pre-foam composition, crosslinked pre-foam composition or
combinations thereof); (ii) simultaneously or sequentially with the
softening (when applicable), contacting the pre-foam composition,
crosslinked pre-foam composition or combinations thereof with a
first concentration or first pressure of a physical blowing agent
sufficient to drive an amount of the physical blowing agent into
the pre-foam composition, crosslinked pre-foam composition or
combinations thereof; (iii) changing the concentration or pressure
(e.g., decreasing the pressure or concentration) of the physical
blowing agent to a second concentration or second pressure that is
effective to foam the pre-foam composition, crosslinked pre-foam
composition or combinations thereof, thereby forming a foam
composition (e.g., a foam composition having a closed-cell
structure); and, (iv) following the changing, cooling (when
applicable) the foam composition to (e.g., cooling to a temperature
below the softening temperature of the foam composition), to form a
foam preform having an initial height. In some examples, this
process is conducted with a composition comprising, consisting
essentially of or consisting of a crosslinked pre-foam
composition.
[0081] In other examples, the foam preform is prepared by (i)
contacting (e.g., dissolving or suspending) the pre-foam
composition, crosslinked pre-foam composition or combinations
thereof with a first concentration of a chemical blowing agent, in
some examples, at or above a softening temperature of the pre-foam
composition, crosslinked pre-foam composition or combinations
thereof; (ii) triggering the chemical blowing agent to foam the
pre-foam composition, crosslinked pre-foam composition or
combinations thereof, thereby forming a foam composition (e.g., a
foam composition having a closed-cell structure); and, (iii)
following the triggering, in some examples, cooling the foam
composition to, e.g., a temperature below its softening
temperature, to form a foam preform having an initial height. In
some examples, this process is conducted with a composition
comprising, consisting essentially of or consisting of a
crosslinked pre-foam composition. In some examples, the
"triggering" of the chemical blowing agent is performed by any
suitable method, including heating the pre-foam composition,
crosslinked pre-foam composition or combinations thereof comprising
a concentration of the chemical blowing agent to a temperature
sufficient to "trigger" the chemical blowing agent, wherein the
concentration of the chemical blowing agent is effective to foam
the pre-foam composition, crosslinked pre-foam composition or
combinations thereof, thereby forming a foam composition (e.g., a
foam composition having a closed-cell structure).
[0082] In some examples, the contacting comprises contacting at a
pressure of from about 10 MPa to about 100 MPa (e.g., from about 30
MPa to about 100 MPa, about 20 MPa to about 80 MPa, about 30 MPa to
about 60 MPa or about 40 MPa to about 70 MPa).
[0083] In some examples, whether the foam preform is prepared using
a physical or chemical blowing agent, a foamed composition (e.g, in
the form of a foam preform) can be compression molded. For example,
the foamed composition can be compression molded by placing the
foam preform in a compression mold having a height less than the
initial height of the foam preform and closing the mold, thereby
compressing the foam preform to the height of the mold.
Simultaneously or sequentially with the compressing, the foam
preform can be heated in the closed compression mold. During the
compression molding, the temperature of at least a portion of the
foam preform in the closed mold can be raised to a temperature
within .+-.30.degree. C. of the softening temperature of the foam
composition. The temperature can be raised by heating the closed
mold. Following the raising of the temperature, while the foam
preform remains closed in the compression mold, the temperature of
at least a portion of the foam preform can be lowered. The
temperature can be lowered by cooling the closed mold. The lowering
can lower the temperature of at least a portion of the foam preform
to a temperature at least 35.degree. C. below the softening
temperature of the foamed composition, thereby forming the
compression molded foam. Following the cooling, the compression
mold can be opened, and the compression molded foam can be removed
from the compression mold.
[0084] Some examples contemplated herein are directed to
compression molded components of articles of footwear or athletic
equipment made in accordance with the compositions and processes
described herein.
[0085] Other examples contemplated herein are directed to methods
of manufacturing articles of footwear or athletic equipment. For
example, the method can comprise providing a compression molded
foam component of an article of footwear in accordance with the
present disclosure, and combining the component with a footwear
upper and an outsole to form the article of footwear. Similarly,
the method can comprise providing a compression molded foam
component of an article of athletic equipment in accordance with
the present disclosure, and combining the compression molded foam
component with other components to form a finished article of
athletic equipment.
[0086] One method of making a compression molded foam (and
compression molded foam articles) described herein comprises
forming a foam preform and compression molding the foam preform to
make a compression molded foam. In some examples, the foam preforms
of the various examples described herein are obtained by blowing
the pre-foam composition, the crosslinked composition, or both the
pre-foam composition and the crosslinked composition by about 150%
to about 240% (e.g., from about 150% to about 220%; about 150% to
about 200%, about 175% to about 225%, about 180% to about 230% or
about 160% to about 240%) in at least one dimension (e.g., the
vertical dimension) using a blowing agent. In some examples, the
blown pre-foam composition, the crosslinked composition, or both
the pre-foam composition and the crosslinked composition can be
compression molded to about 120% to about 200% (e.g., from about
120% to about 180%; about 130% to about 190%; about 150% to about
200%; or about 160% to about 190%) in at least one dimension.
[0087] Thus for example, if the foaming of the pre-foam
composition, the crosslinked composition, or both the pre-foam
composition and the crosslinked composition is about 200%, the
blown pre-foam composition, the crosslinked composition, or both
the pre-foam composition and the crosslinked composition can be
compression molded by a net 20% by compression molding to about
180%. In another example, if the pre-foam composition, the
crosslinked composition, or both the pre-foam composition and the
crosslinked composition is blown into a 20 mm (height).times.10 cm
(width).times.5 cm (depth) slab, and the slab is compression molded
in the height direction by 20%, the compression molded slab would
have the dimensions 18 mm (height).times.10 cm (width).times.5 cm
(depth). In some examples, the compression molding is substantially
maintained.
[0088] In some examples, the foam preform is made using a process
that involves impregnating a pre-foam composition, a crosslinked
pre-foam composition or combinations thereof (e.g., at or above a
softening temperature of the pre-foam composition, crosslinked
pre-foam composition or combinations thereof) with a physical
blowing agent at a first concentration or first pressure. The
impregnated pre-foam composition, crosslinked pre-foam composition
or combinations thereof can then be foamed, or can be cooled (when
applicable) and re-softened (when applicable) for blowing at a
later time. In some instances, the impregnated pre-foam
composition, crosslinked pre-foam composition or combinations
thereof is foamed by reducing the concentration or pressure of the
physical blowing agent. The reduction in concentration of the
physical blowing agent can release additional amounts of the
impregnated physical blowing agent from the pre-foam composition,
crosslinked pre-foam composition or combinations thereof, to
further blow the pre-foam composition, crosslinked pre-foam
composition or combinations thereof, forming a foam composition
(e.g., a foam composition having a closed-cell structure).
[0089] In some examples, the compression molding process is
conducted by heating the foam preform in a closed compression mold.
The foam preform is heated to a temperature close to its softening
temperature, to allow the foam to retain the shape of the
compression mold. For example, the foam preform can be heated to a
temperature within .+-.30.degree. C. of its softening temperature,
or within .+-.20.degree. C. of its softening temperature, or within
.+-.10.degree. C. of its softening temperature, or within
.+-.5.degree. C. of its softening temperature. For example, the
foam preform can be heated to a temperature of from about
100.degree. C. to about 250.degree. C., or of from about
140.degree. C. to about 220.degree. C., or of from about
100.degree. C. to about 150.degree. C., or of from about
130.degree. C. to about 150.degree. C.
[0090] The material used to form the compression mold can be any
material which can withstand the temperatures used during the
process, such as machined metals, including aluminum. The
compression mold can be made using two pieces, such as a top and a
bottom mold. Depending on the shape of the foam component to be
molded, a multiple-piece mold may be used in order to more easily
release the compression molded foam from the mold.
[0091] The compression molding of the foam preform in the
compression mold can result in a closed skin forming on the final
compression molded foam component. However, care should be taken
during the compression molding not to subject the foam preform to
conditions such that more than a desired amount of the closed cell
structures of the foam collapse. One way to avoid collapsing more
than a desired amount of the closed cell structures is to control
the temperature of the polymeric composition, for example, by
controlling the temperature of the mold. For example, during the
compression molding step, the heating of the foam preform in the
compression mold can be conducted for time of from 100 seconds to
1,000 seconds, or of from 150 seconds to 700 seconds.
[0092] Once the foam preform has been heated in the compression
mold at the appropriate temperature for the desired length of time
to soften the preform to the desired level, the softened preform is
cooled, for example, to a temperature at least 35.degree. C. below
its softening temperature, or at least 50.degree. C. below its
softening temperature, or at least 80.degree. C. below its
softening temperature, to re-solidify the softened foam, thereby
forming the compression molded foam. Once cooled, the compression
molded foam component is removed from the compression mold.
Following the heating, the cooling of the foam preform in the
compression mold can be conducted for a time of from 50 to 1,000
seconds, or for a time of from 100 to 400 seconds.
[0093] Compositions
[0094] In various aspects, compositions are provided that can be
foamed, i.e. can be used to form a foam composition. In some
aspects, these compositions are referred to as a "pre-foam
composition." In some aspects, the compositions can be used to
generate foam compositions that are soft and have a high energy
return making them useful for footwear. The compositions can be
used to generate foams using any of a variety of methods known in
the art. In some aspects, the foams are generated using injection
molding or injection molding followed by compression molding
techniques. The foamed compositions can include components of
articles of footwear as described above, for example a midsole 146
as depicted in FIGS. 1A-1B.
[0095] The compositions described herein, when used to form foams,
in some aspects produced foams having surprisingly high energy
return/resiliency values. These compositions also, when used to
form foams, in some aspects produce foams having high split-tear
values. The compositions can, in some aspects, be used to produce
foams having other beneficial properties, including additional
properties beneficial for use in footwear including as cushioning
components. The compositions of the present disclosure can be
foamed and/or molded using various methods. In one example, the
polymeric compositions can be foamed as part of an injection
molding process. Optionally, the injection molded foam can
subsequently be compression molded. Compression molding of the
injection molded foam can modify the properties of the polymeric
foam, such as reducing the compression set of the foam, which can
be beneficial for foams used in footwear-related applications.
Foams formed from the polymeric compositions of the present
disclosure can be used in footwear-related applications without
being compression molded.
[0096] In some aspects, a composition is provided including an
A-B-A block copolymer, wherein each of the A blocks have styrenic
repeat units, the B block is a random copolymer of ethylene and a
first alpha-olefin having 3 to 8 carbon atoms (e.g. 3, 4, 5, 6, 7,
or 8 carbon atoms), and wherein the A-B-A-block copolymer includes
about 10% to 50%, about 10% to 40%, about 15% to 40%, or about 15%
to 30% of the A blocks by weight based upon an entire weight of the
A-B-A block copolymer; an olefinic block copolymer, wherein the
olefinic block copolymer is a copolymer of ethylene and a second
alpha-olefin having about 4 to 14, about 6 to 12, or about 6 to 10
carbon atoms, and wherein the olefinic block copolymer has one or
more blocks rich in the ethylene and one or more blocks rich in the
second alpha-olefin; and an alpha-olefin linking polymer, wherein
the alpha-olefin linking polymer is a copolymer of ethylene and a
third alpha-olefin having about 2 to 24, about 3 to 24, about 3 to
18, or about 6 to 18 carbon atoms, and wherein the alpha-olefin
linking polymer has an alpha-olefin monomer content of about 10% to
50%, about 10% to 40%, about 15% to 40%, or about 15% to 30% by
weight based upon an entire weight of the alpha-olefin linking
polymer.
[0097] In some aspects, a composition is provided including an
A-B-A block copolymer, wherein each of the A blocks include repeat
units according to the following formula
##STR00001##
where each occurrence of R.sup.1 is independently a hydrogen,
halogen, hydroxyl, or a substituted or unsubstituted alkyl group
having from 1 to 18, 1 to 15, 1 to 12, 3 to 18, 3 to 15, or 3 to 12
carbon atoms; where each occurrence of R.sup.2 is independently
none or a substituted or unsubstituted alkyl group having from 1 to
15, 1 to 12, 1 to 8, 3 to 8, 3 to 12, or 3 to 15 carbon atoms;
wherein the B block is a random copolymer of ethylene and a first
alpha-olefin having about 3 to 12, 3 to 10, or 3 to 8 carbon atoms;
and wherein the A-B-A-block copolymer includes about 10% to 50%,
about 10% to 40%, about 15% to 40%, or about 15% to 30% of the A
blocks by weight based upon an entire weight of the A-B-A block
copolymer; an olefinic block copolymer, wherein the olefinic block
copolymer is a copolymer of ethylene and a second alpha-olefin
having about 4 to 14, about 6 to 12, or about 6 to 10 carbon atoms,
and wherein the olefinic block copolymer has one or more blocks
rich in the ethylene and one or more blocks rich in the second
alpha-olefin; and an alpha-olefin linking polymer, wherein the
alpha-olefin linking polymer is a copolymer of ethylene and a third
alpha-olefin having bout 2 to 24, about 3 to 24, about 3 to 18, or
about 6 to 18 carbon atoms; wherein a ratio II of a total parts by
weight of the A-B-A block copolymer present in the composition to a
total parts by weight of the linking polymer present in the is from
about 1.00 to 5.00, about 1.00 to 4.00, about 1.50 to 4.00, about
1.50 to 3.50, about 1.00 to 3.00, or about 2.00 to 4.00.
[0098] In some aspects, a composition is provided including an
A-B-A block copolymer, wherein each of the A blocks include repeat
units according to the following formula
##STR00002##
where each occurrence of R.sup.1 is independently a hydrogen,
halogen, hydroxyl, or a substituted or unsubstituted alkyl group
having from 1 to 18, 1 to 15, 1 to 12, 3 to 18, 3 to 15, 3 to 12, 1
to 8, 3 to 8, 1 to 5, or 3 to 5 carbon atoms; where each occurrence
of R.sup.2 is independently none or a substituted or unsubstituted
alkyl group having from 1 to 15, 1 to 12, 1 to 8, 3 to 8, 3 to 12,
3 to 15, 1 to 8, 1 to 5, or 1 to 3 carbon atoms; wherein the B
block is a random copolymer of ethylene and a first alpha-olefin
having about 3 to 12, 3 to 10, or 3 to 8 carbon atoms; and wherein
the A-B-A-block copolymer includes about 10% to 50%, about 10% to
40%, about 15% to 40%, or about 15% to 30% of the A blocks by
weight based upon an entire weight of the A-B-A block copolymer; an
olefinic block copolymer, wherein the olefinic block copolymer is a
copolymer of ethylene and a second alpha-olefin having about 4 to
14, about 6 to 12, or about 6 to 10 carbon atoms, and wherein the
olefinic block copolymer has one or more blocks rich in the
ethylene and one or more blocks rich in the second alpha-olefin;
and an alpha-olefin linking polymer, wherein the alpha-olefin
linking polymer is a copolymer of ethylene and a third alpha-olefin
having bout 2 to 24, about 3 to 24, about 3 to 18, or about 6 to 18
carbon atoms.
[0099] In some aspects, the alpha-olefin linking polymer has an
alpha-olefin monomer content of about 10% to 50%, about 10% to 45%,
about 15% to 45%, about 15% to 40%, or about 20% to 40% by weight
based upon an entire weight of the alpha-olefin linking
polymer.
[0100] In some aspects, each of the A blocks include a large amount
of polystyrene. For example, each of the A blocks can include at
least 80%, 90% or more styrene repeat units based upon the number
of repeat units in the A block. In some aspects, each of the A
blocks consists essentially of polystyrene.
[0101] In some aspects, each of the B blocks includes a random
copolymer of ethylene and a first alpha-olefin having 4, 5, 6, 7,
or 8 carbon atoms. In some aspects, the B block is essentially a
random copolymer of ethylene and octene, or is random copolymer of
ethylene and butadiene.
[0102] In some aspects there can be more than one alpha-olefin
linking polymer present in the composition. For example, in some
aspects, the composition includes a first alpha-olefin linking
polymer and a second alpha-olefin linking polymer, wherein the
first alpha-olefin linking polymer and the second alpha-olefin
linking polymer are copolymers of ethylene and 1-butene, each
having a different ratio of ethylene to 1-butene monomer content in
the copolymer.
[0103] In some aspects, the composition includes about 5 parts by
weight to about 15 parts by weight of the A-B-A block copolymer,
about 10 parts by weight to about 20 parts by weight of the
olefinic block copolymer, and about 25 parts by weight to about 35
parts by weight of the alpha-olefin linking polymers based upon an
entire weight of the composition.
[0104] In some aspects, the composition includes an ethylene-vinyl
acetate copolymer having a vinyl acetate content of about 10% to
about 45% by weight based upon the weight of the ethylene-vinyl
acetate copolymer.
[0105] In various aspects, the composition also includes comprising
an ethylene-vinyl acetate copolymer having a vinyl acetate content
of about 5% to 55%, about 5% to 50%, about 10% to 50%, about 10% to
45%, or about 15% to 40% by weight based upon the weight of the
ethylene-vinyl acetate copolymer. The
[0106] The A-B-A block copolymer can be at least partially or fully
hydrogenated. In some aspects, the A-B-A block copolymer has a
degree of hydrogenation of about 40% to 99%, about 50% to 99%,
about 50% to 95%, about 50% to 90%, about 50% to 80%, or about 60%
to 80%.
[0107] In some aspects, a composition is provided including
partially hydrogenated thermoplastic elastomeric block copolymer,
an olefinic block copolymer, and an alpha-olefin linking polymer.
The partially hydrogenated thermoplastic elastomeric block
copolymer can include one or more A blocks with aromatic repeat
units, one or more B blocks with aliphatic repeat units, and one or
more first ethylenically unsaturated groups present on one or both
of the aromatic repeat units and the aliphatic repeat units. In
some aspects, the aromatic repeat units are styrenic repeat units.
The olefinic block copolymer can be a copolymer of a first
alpha-olefin and a second alpha-olefin different from the first
alpha-olefin, and wherein the olefinic block copolymer includes one
or more second ethylenically unsaturated groups. The alpha-olefin
linking polymer can include one or more aliphatic sidechains.
[0108] In some aspects, the partially hydrogenated thermoplastic
elastomeric block copolymer can have an A-B block structure or an
A-B-A block structure, wherein the A blocks and B blocks are as
described herein. For example, each of the A blocks can
independently include one or more aromatic repeat units such as
styrene. Each of the B blocks can be an aliphatic polymer block
comprising the one or more first ethylenically unsaturated
units.
[0109] The aromatic repeat units can include any of a variety of
aromatic units. The aromatic repeat units can include aliphatic
backbones having a plurality of aromatic side chains.
[0110] In some aspects, a composition is provided including at
least one polymer containing styrenic repeating units and
non-styrenic repeating units; and at least one C.sub.4-C.sub.100
unsaturated olefin. The styrenic repeat units can include blocks of
polystyrene. The polymer containing styrenic repeating units and
non-styrenic repeating units can be a block copolymer including
blocks of polystyrene and non-styrenic polymeric blocks. In some
examples, the polymer can include non-styrenic repeating units
selected from the group polyester, poly-C.sub.2-C.sub.8-alkylene
units, polyether units, polycarbonate units, polyamide units,
polyketone units, polysiloxane units, and any combination thereof.
The styrene repeating units and non-styrenic repeating units (e.g.,
polyester, poly-C.sub.2-C.sub.8-alkylene units, polyether units,
polycarbonate units, polyamide units, polyketone units,
polysiloxane units, and any combination thereof), can be in any
order. Mixtures of two or more polymers including styrenic repeat
units and non-styrenic repeat units are also contemplated
herein.
[0111] As used herein, unless otherwise dictated by context, when
two of the same type of components are said to be "different" this
means that one has a different chemical composition from the other.
For example, the second alpha-olefin being different from the first
alpha-olefin means the second alpha-olefin has a chemical formula
that is different from the chemical formula of the first
alpha-olefin.
[0112] In some specific examples, the compositions include a
polymer including styrene repeating units and non-styrenic
repeating units, wherein the polymer includes block units of
polyester. In some examples, the polymer including styrenic
repeating units and non-styrenic repeating units includes
poly-C.sub.2-C.sub.8-alkylene units. In some examples, the polymer
including styrenic repeating units and non-styrenic repeating units
of the various examples described herein includes units of
polyethylene. In some examples, the polymer including styrenic
repeating units and non-styrenic repeating units of the various
examples described herein includes units of polypropylene. In other
examples, the polymer including styrenic repeating units and
non-styrenic repeating units of the various examples described
herein includes units of polybutylene. In still other examples, the
polymer including styrene repeating units and non-styrenic
repeating units of the various examples described herein includes
units of polybutadiene. In yet other examples, the polymer
including styrenic repeating units and non-styrenic repeating units
of the various examples described herein includes units of
polyisoprene. The non-styrenic repeating units of the polymer can
include polyethylene, polypropylene, polybutylene, polybutadiene,
polyisoprene, or any combination thereof, and can be present in the
polymer in any order.
[0113] In some examples, when the polymer comprising styrene
repeating units and non-styrenic repeating units described herein
comprise polyethylene, the polyethylene content of the polymer
comprising styrene repeating units and non-styrenic repeating units
is from about 50 mol % to about 80 mol % (e.g., from about 50 mol %
to about 75 mol %; about 60 mol % to about 80 mol %; about 55 mol %
to about 70 mol %; about 65 mol % to about 80 mol %; or about 70
mol % to about 80 mol %).
[0114] In some examples the polymer comprising styrene repeating
units and non-styrenic repeating units is a
PS.sub.q--X.sup.1.sub.n--X.sup.2.sub.n--X.sup.3.sub.p block
copolymer wherein: PS represents polystyrene; X.sup.1 is a
poly-C.sub.2-C.sub.8-alkylene; X.sup.2 is a
poly-C.sub.2-C.sub.8-alkylene; X.sup.3 is polyether, polyester,
polycarbonate, polyamide, polyketone or polysiloxane; the
subscripts q, n, m, and p represent mole fractions; 1>q>0, n
is 0 to 1, m is 0 to 1, and p is 0 to 1, provided that q+n+m+p=1;
and the order of the PS, X.sup.1, X.sup.2, and X.sup.3 blocks can
be random or in the order shown. In some examples, X.sup.1 is
polyethylene, polypropylene, polybutylene, polybutadiene, or
polyisoprene. In other examples, X.sup.2 is polyethylene,
polypropylene, polybutylene, polybutadiene, or polyisoprene.
[0115] Some examples of polymers comprising styrene repeating units
and non-styrenic repeating units contemplated herein include
styrene-butadiene-styrene block copolymers;
styrene-polybutylene-styrene block copolymers;
styrene-ethylene-butadiene-styrene block copolymers;
styrene-ethylene-polybutylene-styrene block copolymers;
styrene-isoprene-butadiene-styrene block copolymers; and
combinations thereof.
[0116] Generally speaking, the block copolymers, such as the A-B-A
block copolymer or the polymer comprising styrene repeating units
and non-styrenic repeating units described herein, can be at least
partially unsaturated (e.g., comprising ethylenic unsaturation).
Thus, for example, at least one of the repeating units can comprise
ethylenic unsaturation. As used herein, the term "partially
unsaturated" (e.g., comprising ethylenic unsaturation) generally
means that the polymer can have from about 20 mol % to about 60 mol
% unsaturation (e.g., from about 20 mol % to about 50 mol %, about
20 mol % to about 30 mol %; about 25 mol % to about 45 mol %; about
30 mol % to about 50 mol %; about 20 mol % to about 40 mol %; or
about 25 mol % to about 40 mol % unsaturation, such as ethylenic
unsaturation). But it should be understood that, by virtue of the
fact that polymers comprising styrene repeating units comprise
phenyl rings, they will be "partially unsaturated."
[0117] Generally speaking, partial unsaturation makes it possible
to form covalent crosslinking between, for example, the polymer
comprising styrene repeating units and non-styrenic repeating units
(intermolecular and intramolecular); the C.sub.4-C.sub.100
unsaturated olefin (intermolecular and intramolecular); and between
the polymer comprising styrene repeating units and non-styrenic
repeating units and the C.sub.4-C.sub.100 unsaturated olefin.
[0118] Generally speaking, the block copolymers, such as the A-B-A
block copolymer or the polymer comprising styrene repeating units
and non-styrenic repeating units described herein, have a weight
average molecular weight (Mw) from about 25,000 g/mol to about
1.5.times.10.sup.6 g/mol (e.g., from about 250,000 g/mol to about
1.5.times.10.sup.6 g/mol, about 25,000 g/mol to about 100,000
g/mol; about 50,000 g/mol to about 200,000 g/mol, 75,000 g/mol to
about 150,000 g/mol; about 100,000 g/mol to about 300,000 g/mol;
about 250,000 g/mol to about 750,000 g/mol; about 300,000 g/mol to
about 800,000 g/mol; about 250,000 g/mol to about 650,000 g/mol;
about 500,000 g/mol to about 1.5.times.10.sup.6 g/mol; about
750,000 g/mol to about 1.5.times.10.sup.6 g/mol; or about 650,000
g/mol to about 1.3.times.10.sup.6 g/mol).
[0119] Some examples of polymers comprising styrene repeating units
and non-styrenic repeating units include those available from
Kraton Performance Polymers Inc., Houston, Tex., such as
KRATON.RTM. D styrene-butadiene-styrene (SBS) polymer comprising
styrene repeating units and non-styrenic repeating units;
KRATON.RTM. D
styrene-isoprene-styrene/styrene-isoprene-butadiene-styrene polymer
comprising styrene repeating units and non-styrenic repeating units
(SIS)/(SIBS); KRATON.RTM. G
styrene-ethyelen-butadiene-styrene/styrene-ethylene-propylene-styrene
(SEBS/SEPS) polymer comprising styrene repeating units and
non-styrenic repeating units; and KRATON.RTM. FG maleic
anhydride-grafted styrene-ethyelen-butadiene-styrene (SEBS) polymer
comprising styrene repeating units and non-styrenic repeating
units. Some examples of polymer comprising styrene repeating units
and non-styrenic repeating units also include SEPTON.RTM.
hydrogenated polymer comprising styrene repeating units and
non-styrenic repeating units (e.g., SEPTON.RTM. 4055; SEPTON.RTM.
8006; SEPTON.RTM. 4077; and SEPTON.RTM. 4099) available from
Kuraray Co., Ltd., Tokyo, Japan. Other examples of polymer
comprising styrene repeating units and non-styrenic repeating units
include hydrogenated SEBS block copolymers available from Asahi
Kasei Chemicals Corporation (e.g., the various grades of
TUFTEC.RTM. hydrogenated SEBS block copolymers, including
TUFTEC.RTM. P1083). While not being bound by any specific theory,
it is believed that the level of hydrogenation of the polymer
comprising styrene repeating units and non-styrenic repeating
units, which in some examples influences (e.g., reduces) the level
of ethylenic unsaturation of the polymer comprising styrene
repeating units and non-styrenic repeating units, can influence the
crystallinity and/or rigidity of the polymer comprising styrene
repeating units and non-styrenic repeating units. Thus, for
example, partially hydrogenated polymer comprising styrene
repeating units and non-styrenic repeating units (e.g., those that
are about 50 to about 80% hydrogenated) can be less crystalline and
more rigid than their non-hydrogenated counterparts (e.g., those
that are less than about 50% hydrogenated).
[0120] In one aspect, the pre-foam compositions of the various
examples described herein can comprise any suitable amount of a
polymer comprising styrene repeating units and non-styrenic
repeating units. In some examples, the pre-foam compositions
comprise from about 5 wt. % to about 50 wt. % (e.g., from about 5
wt. % to about 20 wt. %; about 15 wt. % to about 40 wt. %; about 10
wt. % to about 45 wt. %; about 25 wt. % to about 50 wt. %; or about
20 wt. % to about 45 wt. %) of the polymer comprising styrene
repeating units and non-styrenic repeating units. In addition, or
alternatively, the polymer comprising styrene repeating units and
non-styrenic repeating units comprises a content of styrene
repeating units from about 5 mol % to about 50 mol % (e.g., from
about 5 mol % to about 20 mol %; about 15 mol % to about 40 mol %;
about 10 mol % to about 45 mol %; about 25 mol % to about 50 mol %;
or about 20 mol % to about 45 mol %). In addition, or
alternatively, the polymer comprising styrene repeating units and
non-styrenic repeating units comprises a content of non-styrenic
repeating units from about 50 mol % to about 95 mol % (e.g., from
about 50 mol % to about 80 mol %, about 60 mol % to about 90 mol %,
about 70 mol % to about 95 mol % or about 75 mol % to about 95 mol
%). In some instances, the sum of the content of styrene repeating
units and the content of non-styrenic repeating units is 100 mol
%.
[0121] In particular examples, the pre-foam compositions described
herein comprise from about 5 parts per hundred of resin (phr) to
about 45 phr of the polymer comprising styrene repeating units and
non-styrenic repeating units component (i.e., the styrenic
copolymer component). The pre-foam compositions can comprise from
about 10 phr to about 40 phr of the styrenic copolymer component.
The pre-foam compositions can comprise from about 12 phr to about
35 phr of the styrenic copolymer component. The pre-foam
compositions can comprise from about 15 phr to about 35 phr of the
styrenic copolymer component. The pre-foam compositions can
comprise from about 10 phr to about 30 phr of the styrenic
copolymer component. The pre-foam compositions can comprise from
about 10 phr to about 25 phr of the styrenic copolymer component.
The pre-foam compositions can comprise from about 10 phr to about
22 phr of the styrenic copolymer component.
[0122] As used herein, the stryrenic copolymer component is
understood to refer to all the polymers present in the pre-foam
composition which individually have both styrene repeating units
and non-styrenic repeating units. Thus, the concentration of the
styrenic copolymer component in a pre-foam composition refers to
the total concentration of each polymer comprising styrene
repeating units and non-styrenic repeating units present in the
composition. In some pre-foam compositions, the styrenic copolymer
component can be formed of only a single polymer comprising styrene
repeating units and non-styrenic repeating units. In other pre-foam
compositions, the styrenic copolymer component can be by formed of
a plurality of polymers each of which has both styrene repeating
units and non-styrenic repeating units.
[0123] The pre-foam composition described herein also comprises at
least one C.sub.4-C.sub.100 unsaturated olefin. The
C.sub.4-C.sub.100 unsaturated olefin can be a
C.sub.8-C.sub.50-unsaturated olefin. The C.sub.4-C.sub.100
unsaturated olefin can be a C.sub.12-C.sub.30-unsaturated olefin.
The C.sub.4-C.sub.100 unsaturated olefin can be a
C.sub.16-C.sub.100-unsaturated olefin. The C.sub.4-C.sub.100
unsaturated olefin can be a C.sub.50-C.sub.100-unsaturated olefin.
As used herein, the C.sub.x-C.sub.y nomenclature is understood to
specify the carbon length of the unsaturated olefin, not the
location of unsaturation. Mixtures of two or more C.sub.4-C.sub.100
unsaturated olefins are also contemplated herein. In some examples,
a C.sub.4-C.sub.100 unsaturated olefin can be pre-polymer (e.g., a
monomer); a linear oligomer; a polymer.
[0124] As used herein, the term "unsaturated olefin" is understood
to encompass any C.sub.4-C.sub.100 olefin comprising at least one
terminal C--C double bond and a total of about 4 to about 100
(e.g., 8 to 50; 12 to 30; 4 to 20; 10 to 50; 30 to 90; 20 to 100;
50 to 75; or 20 to 80) total carbon atoms. Additional carbon-carbon
double bonds can be present in the unsaturated olefin. Examples of
C.sub.4-C.sub.100 unsaturated olefins include propene, 1-butene,
4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene,
1-tetradecene, 1-hexadecene, and 1-octadecene. In other examples,
C.sub.4-C.sub.100 unsaturated olefins can be alkyl- or
cycloalkyl-substituted unsaturated olefins. As used herein, the
term "unsaturated olefin" is also understood to encompass any
C.sub.4-C.sub.100 olefin comprising a plurality of polymerized
units, wherein at least a portion of the polymerized units include
at least one terminal C--C double bond and a total of about 4 to
about 100 (e.g., 8 to 50; 12 to 30; 4 to 20; 10 to 50; 30 to 90; 20
to 100; 50 to 75; or 20 to 80) total carbon atoms. In other words,
the unsaturated olefin can be an unsaturated olefin polymer or
copolymer, including unsaturated olefin block copolymers.
Additional carbon-carbon double bonds can be present in the
unsaturated olefin polymer or copolymer. Examples of unsaturated
olefinic copolymers include the TAFMER.RTM. unsaturated olefin
copolymers available from Mitsui Chemicals America, Inc., Rye
Brook, N.Y. (e.g., TAFMER.RTM. DF110 and TAFMER.RTM. DF605
ethylene/unsaturated olefin copolymers); and ENGAGE.RTM. and
INFUSE.RTM. olefin block copolymers, both available from The Dow
Chemical Company, Midland, Mich. (e.g., INFUSE.RTM. 9107 olefin
block copolymer).
[0125] In some examples, the pre-foam compositions of the various
examples described herein can comprise one or more polymers
comprising styrene repeating units and non-styrenic repeating
units, one or more C.sub.4-C.sub.100 unsaturated olefins, and one
or more olefin block copolymers.
[0126] In some examples, C.sub.4-C.sub.100 unsaturated olefins can
comprise one or more heteroatoms (e.g., --O--, NR.sup.1--,
--S(O).sub.q-- (wherein q is an integer from 0 to 2) and
combinations thereof). An example of such heteroatom-interrupted
C.sub.4-C.sub.100 unsaturated olefins include allyl ether and
allyl-terminated polyethylene glycol.
[0127] In particular examples, the pre-foam compositions described
herein comprise from about 30 phr to about 90 phr of the
C.sub.4-C.sub.100 unsaturated olefin component (i.e., the
unsaturated olefin component). The pre-foam compositions can
comprise from about 35 phr to about 85 phr of the unsaturated
olefin component. The pre-foam compositions can comprise from about
40 phr to about 80 phr of the unsaturated olefin component. The
pre-foam compositions can comprise from about 45 phr to about 75
phr of the unsaturated olefin component. The pre-foam compositions
can comprise from about 40 phr to about 85 phr of the unsaturated
olefin component. The pre-foam compositions can comprise from about
45 phr to about 85 phr of the unsaturated olefin component. The
pre-foam compositions can comprise from about 43 phr to about 82
phr of the unsaturated olefin component.
[0128] As used herein, the unsaturated olefin component is
understood to refer to all the C.sub.4-C.sub.100 unsaturated
olefins present in the pre-foam composition. Thus, the
concentration of the unsaturated olefin component in a pre-foam
composition refers to the total concentration of each
C.sub.4-C.sub.100 unsaturated olefin present in the composition,
including all C.sub.4-C.sub.100 unsaturated olefin monomers,
C.sub.4-C.sub.100 unsaturated olefin oligomers, C.sub.4-C.sub.100
unsaturated olefin polymers, and C.sub.4-C.sub.100 unsaturated
olefin copolymers. In some pre-foam compositions, the unsaturated
olefin component can be formed of only a single C.sub.4-C.sub.100
unsaturated olefin, such as, for example, a single
C.sub.4-C.sub.100 unsaturated olefin copolymer. In other pre-foam
compositions, the unsaturated olefin component can be formed of a
plurality of C.sub.4-C.sub.100 unsaturated olefin, such as, for
example, a plurality of C.sub.4-C.sub.100 unsaturated olefin
copolymers.
[0129] The compositions of the various examples described herein
can also comprise at least one ethylene vinyl acetate copolymer, in
addition to the polymer comprising styrene repeating units and
non-styrenic repeating units; and the C.sub.4-C.sub.100 unsaturated
olefin. And, in some instances, the at least one ethylene vinyl
acetate copolymer comprises two different ethylene vinyl acetate
copolymers.
[0130] In some examples, the at least one ethylene vinyl acetate
copolymer is a random copolymer. In other examples, the at least
one ethylene vinyl acetate copolymer comprises an ethylene content.
In still other examples, the at least one ethylene vinyl acetate
copolymer is at least partially unsaturated (e.g., comprises
ethylenic unsaturation). In some examples, the pre-foam composition
comprises about 20 wt. % to about 60 wt. % (e.g., from about 25 wt.
% to about 50 wt. %; about 30 wt. % to about 50 wt. %; about 40 wt.
% to about 60 wt. %; about 30 wt. % to about 60 wt. %; or about 45
wt. % to about 60 wt. %) of the at least one ethylene vinyl acetate
copolymer. A suitable ethylene vinyl acetate copolymer includes
EVLAX.RTM. 40L-03 ethylene vinyl acetate resin available from E.I.
DuPont de Nemours Co., Wilmington, Del. Other suitable ethylene
vinyl acetate copolymers include EVATHENE.RTM. UE659 and
EVATHENE.RTM. UE3300 ethylene vinyl acetate copolymers available
from USI Corporation, Taiwan, ROC.
[0131] In some examples, the pre-foam compositions comprise about 1
to about 10 wt. % of a first ethylene vinyl acetate copolymer and
about 5 to about 50 wt. % of a second ethylene vinyl acetate
copolymer, wherein the wt. % amounts are relative to the weight of
the pre-foam composition.
[0132] In one example, when the at least one ethylene vinyl acetate
copolymer comprises two different ethylene vinyl acetate
copolymers, the at least two different ethylene vinyl acetate
copolymers can differ in at least vinyl acetate content. Thus, for
example, a first ethylene vinyl acetate copolymer can comprise
about 15 to about 40 mol % vinyl acetate (e.g., from about 15 to
about 30 mol %; about 25 to about 35 mol %; or about 20 mol % to
about 40 mol %) and a second ethylene vinyl acetate copolymer
comprises about 15 to about 30 mol % (e.g., from about 15 to about
25 mol %; about 20 mol % to about 30 mol %; or about 15 mol % to
about 30 mol %) vinyl acetate.
[0133] In particular examples, the pre-foam compositions described
herein do not include an ethylene vinyl acetate copolymer (EVA). In
other words, the pre-foam compositions described herein can be free
of an EVA component.
[0134] Alternatively, the pre-foam compositions described herein
can comprise from about 5 phr to about 50 phr of the EVA component.
The pre-foam compositions can comprise from about 10 phr to about
45 phr of the EVA component. The pre-foam compositions can comprise
from about 20 phr to about 45 phr of the EVAcomponent. The pre-foam
compositions can comprise from about 25 phr to about 40 phr of the
EVA component. The pre-foam compositions can comprise from about 25
phr to about 35 phr of the EVA component. The pre-foam compositions
can comprise from about 30 phr to about 37 phr of the EVA
component. As used herein, the EVA component is understood to refer
to all the ethylene vinyl acetate copolymers present in the
pre-foam composition. Thus, the concentration of the EVA component
in a pre-foam composition refers to the total concentration of each
ethylene vinyl acetate copolymer present in the composition. In
some pre-foam compositions, the EVA component can be formed of only
a single ethylene vinyl acetate copolymer. In other pre-foam
compositions, the EVA component can be formed of a plurality of
different ethylene vinyl acetate copolymers.
[0135] Particular ratios of the components of the pre-foam
compositions have been found to produce foams having beneficial
properties. As used herein and unless otherwise indicated or
dictated by context, the ratio of a first component to a second
component is understood to the parts per hundred of resin (phr) of
the first component divided by the phr of the second component
present in the composition. In some aspects, a sum of ratios is
presented, which is understood to mean the sum of the specific
ratios described.
[0136] The composition can be a composition having a ratio of the
styrenic copolymer component to the unsaturated olefin component of
about 0.1 to about 1.0. The ratio of the styrenic copolymer
component to the unsaturated olefin component can be from about
0.05 to about 0.40. The ratio of the styrenic copolymer component
to the unsaturated olefin component can be from about 0.1 to about
0.3. The ratio of the styrenic copolymer component to the
unsaturated olefin component can be from about 0.15 to about
0.32.
[0137] The composition can be a composition having a ratio of the
styrenic copolymer component to the EVA component of about 0.2 to
about 2.0. The ratio of the styrenic copolymer component to the EVA
component can be from about 0.3 to about 1.0. The ratio of the
styrenic copolymer component to the EVA component can be from about
0.3 to about 0.8. The ratio of the styrenic copolymer component to
the EVA component can be from about 0.35 to about 0.72.
[0138] The composition can be a composition having a ratio of the
unsaturated olefin component to the EVA component of about 2.0 to
about 4.0. The ratio of the unsaturated olefin component to the EVA
component can be from about 1.5 to about 3.0. The ratio of the
unsaturated olefin component to the EVA component can be from about
1.5 to about 2.5. The ratio of the unsaturated olefin component to
the EVA component can be from about 2.0 to about 2.5
[0139] When the composition includes an EVA component, the
composition can have a sum of the ratio of the styrenic copolymer
component to the unsaturated olefin component, of the ratio of the
styrenic copolymer component to the EVA component, and of the ratio
of the unsaturated olefin component to the EVA component of about
1.5 to about 4.5. The sum of the ratios for the composition can be
from about 2.0 to about 4.5. The sum of the ratios for the
composition can be from about 2.2 to about 3.8. The sum of the
ratios for the composition can be from about 2.5 to about 3.5.
[0140] It has been found that, in some aspects, a ratio II of a
total parts by weight of the A-B-A block copolymer present in the
composition to a total parts by weight of the linking polymer
present in the composition has a strong impact on the desired
softness and energy return of the foamed compositions. In some
aspects, foam compositions having an improved softness and energy
return can be formed from compositions having a ratio II from about
1.00 to 5.00, about 1.00 to 4.00, about 1.50 to 4.00, about 1.50 to
3.50, about 1.00 to 3.00, or about 2.00 to 4.00.
[0141] The compositions of the various examples described herein
can also comprise a blowing agent, a free-radical initiator or
combinations thereof.
[0142] The blowing agent can be any appropriate type of physical
blowing agent known in the art including nitrogen, carbon dioxide,
hydrocarbons (e.g., propane, pentane, isopentane, and
cyclopentane), chlorofluorocarbons, noble gases (e.g., helium (He),
neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe)) and/or
mixtures thereof. In one example, the blowing agent comprises
nitrogen. The blowing agent may be supplied in any flowable
physical state such as a gas, a liquid, or a supercritical fluid.
According to one example, a blowing agent source provides a blowing
agent (e.g., carbon dioxide, nitrogen, and methanol) that is in a
supercritical fluid state upon contacting (e.g., injection into)
the pre-foam compositions of the various examples described herein,
e.g., when the pre-foam compositions are formed in an extruder
(e.g., a twin-screw extruder).
[0143] Alternatively, the blowing agent can be any appropriate type
of chemical blowing agent known in the art including carbonates
(e.g., ammonium carbonate and carbonates of alkali metals), azo
compounds, diazo compounds, and combinations thereof. Chemical
blowing agents include 2,2'-azobis(2-cyanobutane),
2,2'-azobis(methylbutyronitrile), azodicarbonamide,
p,p'-oxybis(benzene sulfonyl hydrazide), p-toluene sulfonyl
semicarbazide, p-toluene sulfonyl hydrazide, and combinations
thereof. In the case of chemical blowing agents, gaseous products
(e.g., nitrogen gas) and other by-products are formed by a chemical
reaction(s), promoted by the process or by a reacting polymer's
exothermic heat. Since the blowing reaction occurs forming low
molecular weight compounds acting as the blowing gas, additional
exothermic heat may also be released.
[0144] In some examples, the compositions described herein may
require a temperature (e.g., from heating) of from about
130.degree. C. to about 210.degree. C. (e.g., from about
150.degree. C. to about 190.degree. C. or 165.degree. C. to about
195.degree. C.--such as temperatures to which an extruder and/or a
mold might be heated) to "trigger" the chemical blowing agent to
"decompose" to produce the gas(es) necessary to transform the
pre-foam compositions of the various examples described herein into
the foam compositions of the various examples described herein.
[0145] Examples of blowing agents include UNICELL brand blowing
agents, such as UNICELL-D600 MT, available from Dongjin Semichem
Co., Ltd., Seoul, Korea.
[0146] In some examples, a combination of physical and chemical
blowing agents can be used.
[0147] The pre-foam compositions of the various examples described
herein can also comprise metal oxides, organic acids, fillers,
nucleating agents, and combinations thereof. Examples of metal
oxides include zinc oxide, titanium dioxide, and combinations
thereof. Examples of organic acids include
C.sub.3-C.sub.30-alkanoic acids (e.g., C.sub.14-C.sub.30-alkanoic
acids such as fatty acids) such as stearic acid and combinations of
two or more C.sub.3-C.sub.30-alkanoic acids. Calcium carbonate is
an example of a material which can be used both as a filler and as
a nucleating agent.
[0148] The pre-foam compositions of the various examples described
herein can also comprise one or more crosslinking agents. Examples
of crosslinking agents include aliphatic unsaturated amides, such
as methylenebisacryl- or -methacrylamide or ethylenebisacrylamide;
aliphatic esters of polyols or alkoxylated polyols with
ethylenically unsaturated acids, such as di(meth)acrylates or
tri(meth)acrylates of butanediol or ethylene glycol, polyglycols or
trimethylolpropane; di- and triacrylate esters of
trimethylolpropane; acrylate and methacrylate esters of glycerol
and pentaerythritol; allyl compounds, such as allyl (meth)acrylate,
alkoxylated allyl (meth)acrylate, triallyl cyanurate, triallyl
isocyanurate, maleic acid diallyl ester, poly-allyl esters, vinyl
trimethoxysilane, vinyl triethoxysilane, polysiloxane comprising at
least two vinyl groups, tetraallyloxyethane, tetraallyloxyethane,
triallylamine, and tetraallylethylenediamine. Mixtures of the
crosslinking agents can also be employed.
[0149] The pre-foam compositions of the various examples described
herein can also comprise one or more free-radical initiators, such
as an organic peroxide, a diazo compound (e.g., those described in
U.S. Pat. No. 6,303,723, which is incorporated by reference as if
fully set forth herein) or combinations of two or more free-radical
initiators. Examples of organic peroxides that can be used as
free-radical initiators include dicumyl peroxide;
n-butyl-4,4-di(t-butylperoxy) valerate;
1,1-di(t-butylperoxy)3,3,5-trimethylcyclohexane;
2,5-dimethyl-2,5-di(t-butylperoxy) hexane; di-t-butyl peroxide;
di-t-amyl peroxide; t-butyl peroxide; t-butyl cumyl peroxide;
2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3;
di(2-t-butyl-peroxyisopropyl)benzene; dilauroyl peroxide; dibenzoyl
peroxide; t-butyl hydroperoxide; and combinations thereof.
[0150] The pre-foam compositions of the various examples described
herein can be solids or liquids at a temperature of about
25.degree. C.
[0151] The pre-foam compositions of the various examples described
herein can be crosslinked to form crosslinked pre-foam
compositions. The pre-foam compositions can be crosslinked using
various methods, including chemical crosslinking methods or
crosslinking methods using actinic radiation (e.g., thermal
radiation, UV light, electron beam and gamma radiation). Such
compositions comprise, in some examples, a polymer comprising
styrene repeating units and non-styrenic repeating units, the
polymer crosslinked with a C.sub.4-C.sub.100 unsaturated-olefin
block copolymer comprising blocks of C.sub.4-C.sub.100
unsaturated-olefin olefin. The crosslinking between the polymer
comprising styrene repeating units and non-styrenic repeating units
and the C.sub.4-C.sub.100 unsaturated olefin block copolymer can
occur directly between the molecules of the polymer comprising
styrene repeating units and non-styrenic repeating units and the
C.sub.4-C.sub.100 unsaturated olefin block copolymer, for example,
without an "external" crosslinking agent such as the one or more
crosslinking agents described herein. The crosslinking between the
polymer comprising styrene repeating units and non-styrenic
repeating units and the C.sub.4-C.sub.100 unsaturated olefin block
copolymer can also occur with an "external" crosslinking agent,
such as the one or more crosslinking agents described herein.
[0152] Those of ordinary skill in the art will also recognize that
there can be intramolecular crosslinking occurring between portions
of a polymer comprising styrene repeating units and non-styrenic
repeating units molecule or portions of a C.sub.4-C.sub.100
unsaturated olefin block copolymer. This crosslinking can occur in
the presence or in the absence of an "external" crosslinking agent
such as the one or more crosslinking agents described herein.
[0153] In some examples, the pre-foam compositions of the various
examples described herein can be crosslinked to form crosslinked
pre-foam compositions in the presence of a blowing agent (e.g., a
chemical blowing agent or a physical blowing agent, as described
herein).
[0154] In some examples, the crosslinked pre-foam compositions of
the various examples described herein can be solids or liquids, but
generally are solids (e.g., thermoplastic solids) at a temperature
of about 25.degree. C. or higher (e.g., at a temperature of from
about 25.degree. C. to about 220.degree. C. and a pressure of from
about 500 kPa to about 100 MPa). In some examples, the foam
compositions of the various examples described herein are generally
are solids (e.g., thermoplastic solids) at a temperature of about
25.degree. C. or higher (e.g., at a temperature of from about
25.degree. C. to about 220.degree. C. and a pressure of from about
500 kPa to about 100 MPa).
[0155] In some examples, the crosslinked pre-foam compositions of
the various examples described herein can further comprise at least
one ethylene vinyl acetate copolymer and/or at least one olefin
block copolymer, as each of the terms is defined herein.
[0156] Foam compositions are also contemplated herein and are
interchangeably called "foam preforms." As used herein, the term
"foam compositions" refers to: [0157] a crosslinked pre-foam
composition that is foamed (e.g., foamed using a blowing agent
(physical and/or chemical)) before crosslinking, after crosslinking
or substantially simultaneously with crosslinking; or [0158]
combinations of a pre-foam composition and a crosslinked pre-foam
composition (e.g., a combination of a pre-foam composition and a
crosslinked pre-foam composition, wherein the combination is foamed
(e.g., foamed using a blowing agent (physical and/or chemical))
after the combination is formed either after mixing two such
compositions or after partially crosslinking the pre-foam
composition, such that some crosslinked pre-foam composition is
formed in situ).
[0159] In some examples, the foam compositions of the various
examples described herein can further comprise at least one
ethylene vinyl acetate copolymer and/or at least one olefin block
copolymer, as each of the terms is defined herein.
[0160] Some foam compositions of the various examples described
herein (e.g., foam compositions comprising a polymer comprising
styrene repeating units and non-styrenic repeating units,
crosslinked with a C.sub.4-C.sub.100 unsaturated olefin) can form
solid (e.g., thermoplastic) foam materials. These thermoplastic
foam materials can be used as "foam preforms" and the foam preforms
can subsequently be compression molded. The foam compositions of
the present disclosure can have a density of about 0.08 g/cm.sup.3
to about 0.15 g/cm.sup.3 (e.g., from about 0.10 g/cm.sup.3 to about
0.12 g/cm.sup.3). In some examples, such foam preforms have an
energy return from about 60% to about 85% (e.g., from about 65% to
about 80%; about 65% to about 75%; about 70% to about 80%; or about
75% to about 80%).
[0161] Some foam compositions of the various examples described
herein (e.g., foam preforms) can be compression molded to form
compression molded foam. Such compression molded foam can have a
density of from about 0.15 g/cm.sup.3 to about 0.30 g/cm.sup.3
(e.g., from about 0.15 g/cm.sup.3 to about 0.2 g/cm.sup.3).
Definitions
[0162] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this disclosure belongs. It will
be further understood that terms, such as those defined in commonly
used dictionaries, should be interpreted as having a meaning that
is consistent with their meaning in the context of the
specification and relevant art and should not be interpreted in an
idealized or overly formal sense unless expressly defined
herein.
[0163] All publications, patents, and patent applications cited in
this specification are cited to disclose and describe the methods
and/or materials in connection with which the publications are
cited. All such publications, patents, and patent applications are
herein incorporated by references as if each individual publication
or patent were specifically and individually indicated to be
incorporated by reference. Such incorporation by reference is
expressly limited to the methods and/or materials described in the
cited publications, patents, and patent applications and does not
extend to any lexicographical definitions from the cited
publications, patents, and patent applications. Any lexicographical
definition in the publications, patents, and patent applications
cited that is not also expressly repeated in the instant
specification should not be treated as such and should not be read
as defining any terms appearing in the accompanying claims.
[0164] Although any methods and materials similar or equivalent to
those described herein can also be used in the practice or testing
of the present disclosure, the preferred methods and materials are
now described. Functions or constructions well-known in the art may
not be described in detail for brevity and/or clarity. Aspects of
the present disclosure will employ, unless otherwise indicated,
techniques of nanotechnology, organic chemistry, material science
and engineering and the like, which are within the skill of the
art. Such techniques are explained fully in the literature.
[0165] It should be noted that ratios, concentrations, amounts, and
other numerical data can be expressed herein in a range format.
Where the stated range includes one or both of the limits, ranges
excluding either or both of those included limits are also included
in the disclosure, e.g. the phrase "x to y" includes the range from
`x` to `y` as well as the range greater than `x` and less than `y`.
The range can also be expressed as an upper limit, e.g. `about x,
y, z, or less` and should be interpreted to include the specific
ranges of `about x`, `about y`, and `about z` as well as the ranges
of `less than x`, less than y', and `less than z`. Likewise, the
phrase `about x, y, z, or greater` should be interpreted to include
the specific ranges of `about x`, `about y`, and `about z` as well
as the ranges of `greater than x`, greater than y', and `greater
than z`. In addition, the phrase "about `x` to `y`", where `x` and
`y` are numerical values, includes "about `x` to about `y`". It is
to be understood that such a range format is used for convenience
and brevity, and thus, should be interpreted in a flexible manner
to include not only the numerical values explicitly recited as the
limits of the range, but also to include all the individual
numerical values or sub-ranges encompassed within that range as if
each numerical value and sub-range is explicitly recited. To
illustrate, a numerical range of "about 0.1% to 5%" should be
interpreted to include not only the explicitly recited values of
about 0.1% to about 5%, but also include individual values (e.g.,
1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.5%, 1.1%, 2.4%,
3.2%, and 4.4%) within the indicated range.
[0166] The term "about," as used herein, can include traditional
rounding according to significant figures of the numerical value.
In some aspects, the term about is used herein to mean a deviation
of 10%, 5%, 2.5%, 1%, 0.5%, 0.1%, 0.01%, or less from the specified
value.
[0167] The articles "a" and "an," as used herein, mean one or more
when applied to any feature in aspects of the present disclosure
described in the specification and claims. The use of "a" and "an"
does not limit the meaning to a single feature unless such a limit
is specifically stated. The article "the" preceding singular or
plural nouns or noun phrases denotes a particular specified feature
or particular specified features and may have a singular or plural
connotation depending upon the context in which it is used.
[0168] As used herein, the term "units" can be used to refer to
individual (co)monomer units such that, for example, styrenic
repeat units refers to individual styrene (co)monomer units in the
polymer. In addition, the term "units" can be used to refer to
polymeric block units such that, for example, "styrene repeating
units" can also refer to polystyrene blocks; "units of
polyethylene" refers to block units of poplyethylene; "units of
polypropylene" refers to block units of polypropylene; "units of
polybutylene" refers to block units of polybutylene, and so on.
Such use will be clear from the context.
Examples
[0169] Now having described the aspects of the present disclosure,
in general, the following Examples describe some additional aspects
of the present disclosure. While aspects of the present disclosure
are described in connection with the following examples and the
corresponding text and figures, there is no intent to limit aspects
of the present disclosure to this description. On the contrary, the
intent is to cover all alternatives, modifications, and equivalents
included within the spirit and scope of the present disclosure.
[0170] Materials
[0171] The materials referred to throughout the examples are,
unless otherwise indicated, described in Table 1 below. The
partially hydrogenated SEBS block copolymers from Asahei Kasei
(marketed under the trade name TUFTEC.RTM.) all have an elongation
at break of greater than 650% when measured using ASTM D638. The
P1083 (and the research grade JT-83) have a styrene content of
about 20%, while the P5051 has a styrene content of about 47%. The
SEBS copolymer from KRATON Polymers (KRATON.RTM. G1651E) has a
styrene content of about 30%-33%. The ENGAGE.RTM. polyolefin
elastomers are copolymers of ethylene and octene, while the
TAFMER.RTM. linking polymers are random copolymers of ethylene and
1-butene. For materials where the supplier is not listed in Table 1
(e.g. stearic acid), these materials are generally available from a
variety of suppliers.
TABLE-US-00001 TABLE 1 Materials Used In Examples Trade Name
Ingredient Description Supplier TUFTEC .RTM. P1083 Partially
hydrogenated Aromatic/aliphatic Asahei Kasei SEBS block copolymer
copolymer TUFTEC .RTM. JT-83 Partially hydrogenated
Aromatic/aliphatic Asahei Kasei (research grade of SEBS block
copolymer copolymer P1083) TUFTEC .RTM. P5051 Partially
hydrogenated Aromatic/aliphatic Asahei Kasei SEBS block copolymer
copolymer KRATON .RTM. G1651E partially hydrogenated
Aromatic/aliphatic KRATON SEBS block copolymer copolymer Polymers
Group INFUSE .TM. 9000 OBC Olefin block copolymer Olefinic
Copolymer Dow Chemical Co. INFUSE .TM. 9107 OBC Olefin block
copolymer Olefinic Copolymer Dow Chemical Co. INFUSE .TM. 9530 OBC
Olefin block copolymer Olefinic Copolymer Dow Chemical Co. ENGAGE
.RTM. 8480 Polyolefin elastomer Olefinic Copolymer Dow Chemical Co.
ENGAGE .RTM. 8540 Polyolefin elastomer Olefinic Copolymer Dow
Chemical Co. ENGAGE .RTM. 8440 Polyolefin elastomer Olefinic
Copolymer Dow Chemical Co. TAFME .RTM. DF-110 Alpha-olefin
copolymer Linking Polymer Mitsui Elastomers TAFMER .RTM. DF-605
Alpha-olefin copolymer Linking Polymer Mitsui Elastomers EVA-659
Ethylene vinyl acetate Ethylene vinyl acetate USI copolymer (EVA)
Corporation EVA-3330 Ethylene vinyl acetate EVA USI copolymer
Corporation ELVAX .RTM. 360 Ethylene vinyl acetate EVA DuPont
copolymer ST/AC Stearic Acid Organic acid ZnO Zinc oxide Metal
oxide TiO.sub.2 Titanium Dioxide Metal oxide CaCO.sub.3 Calcium
Carbonate Filler/Nucleating Agent TAC-50GR Triallyl cyanurate
Crosslinking agent Color base Coloring agent 27020 Blue tint
Coloring agent EVA 1375 Red pigment Coloring agent 8502 Black
pigment Coloring agent R929 Coloring agent UNICELL D600-MT Blowing
agent Tramaco (MB-50%) JTR/TL Blowing agent Kumyang COLINK 101-45GE
2,5-Dimethyl-2,5- Free-radical initiator di(tert-
butylperoxy)hexane DCP Dicumyl peroxide Free-radical initiator
Example 1: Batch Process of Preparing Compositions Capable of being
Foamed
[0172] The pre-foam compositions, compositions prior to being
foamed, described in Tables 3 and 4 were prepared. Some of the
pre-foam compositions were first compounded using the components
shown in Table 2 to form pre-foam base compositions (PFBC) 1 and
PFBC 2, according to Example 1. These PFBCs were then used to
prepare the foam compositions shown in Tables 3, 4. The properties
of the foam compositions are described in Table 5. In some
instances, PFC 1 or PFBC 2 were further modified as shown in Tables
3, 4 and 5 by adding additional materials. Other formulations were
prepared directly, without first forming a pre-foam base
composition.
TABLE-US-00002 TABLE 2 Composition of Pre-Foam Base Compositions
Used For Making Pre-Foam Compositions Pre-Foam Pre-Foam Base Base
Composition 1 Composition 2 Formulations (PFBC 1) (PFBC 2) A, B, C
and D phr in phr in phr in Trade Name PFBC1 PFBC2 formulation
TUFTEC .RTM. P1083 10.0 16.6 ** TUFTEC .RTM. P5051 0.0 0.0 **
TUFTEC .RTM. JT-83 0.0 0.0 ** KEATON .RTM. D G1651E 0.0 0.0 **
INFUSE .TM. OBC9000 0.0 0.0 ** INFUSE .TM. OBC9107 15.0 24.9 **
INFUSE .TM. OBC9507 0.0 0.0 ** INFUSE .TM. OBC9530 0.0 0.0 **
ENGAGE .RTM. 8480 0.0 0.0 ** ENGAGE .RTM. 8540 0.0 0.0 ** ENGAGE
.RTM. 8440 0.0 0.0 ** TAFMER .RTM. DF-110 12.0 19.9 ** TAFMER .RTM.
DF-605 18.0 29.9 ** EVA-659 40.0 0.0 ** EVA-3330 5.0 0.0 ** ELVAX
.RTM. 360 0.0 0.0 ** ELVAX .RTM. 40L-03 0.0 0.0 ** ST/AC 1.0 1.7
0.0 ZnO 0.8 1.4 1.5 TiO.sub.2 0.0 0.0 3.6 CaCO.sub.3 0.0 0.0 5.0
TAC-50GR 0.3 0.5 0.0 Color base 11.0 18.3 0.0 27020 0.0 0.0 0.0 EVA
1375 0.0 0.0 0.0 8502 0.0 0.0 0.0 R929 0.0 0.0 0.1 UNICELL D600-MT
11.5 11.5 0.0 JTR/TL 0.0 0.0 9.8 COLINK 101-45GE 0.0 0.0 0.0 DCP
0.7* 0.7* 0.7 *concentration in formulation **: See Table 2 and
3
[0173] The pre-foam compositions were formed using a batch process
where the partially hydrogenated SEBS block copolymer and the
olefin polymer were combined in a kneader for about 20 minutes.
During this time, the kneader temperature was maintained at a
temperature of from about 100.degree. C. to about 120.degree. C. In
some examples, the ethylene vinyl acetate copolymer (the EVA
component of the composition) and/or pigments was added to the
mixture the partially hydrogenated SEBS block copolymer and the
olefin polymer.
[0174] Next, where present, the one or more metal oxide, one or
more organic acid, and one or more crosslinking agent were added to
the mixture. The combined mixture including the partially
hydrogenated SEBS block copolymer and the olefin polymer, as well
as (if present) the EVA along with the metal oxide, organic acid,
and crosslinking agent were mixed in the kneader for about 20
minutes, while the kneader temperature was held at a temperature of
from about 100.degree. C. to about 120.degree. C.
[0175] Next, the kneader temperature was lowered to about
90.degree. C. or below. The combined mixture in the kneader was
then combined with the blowing agent and a free radical initiator.
The kneaded mixture was then subjected to pelletization using a die
that is cooled to maintain the temperature at about 90.degree. C.
or below.
TABLE-US-00003 TABLE 3 Composition of foams Parts Parts Parts Parts
Parts Material by Wt. by Wt. by Wt. by Wt. by Wt. Composition A B C
D E PFBC 1 (MB1) 0.0 0.0 0.0 0.0 0.0 PFBC 2 (MB2) 0.0 0.0 0.0 0.0
70.0 Kraton G1651E 0.0 0.0 0.0 0.0 0.0 TUFTEC .RTM. P1083 0.0 0.0
0.0 0.0 9.3 TUFTEC .RTM. JT-83 20.0 20.0 20.0 20.0 10.0 TUFTEC
.RTM. P5051 0.0 0.0 0.0 0.0 0.0 INFUSE .TM. 9000 OBC 0.0 0.0 0.0
0.0 0.0 INFUSE .TM. 9107 OBC 0.0 0.0 0.0 0.0 13.9 INFUSE .TM. 9530
OBC 0.0 0.0 0.0 20.0 20.0 ENGAGE .RTM. 8440 0.0 0.0 20.0 0.0 0.0
ENGAGE .RTM. 8480 20.0 0.0 0.0 0.0 0.0 ENGAGE .RTM. 8540 0.0 20.0
0.0 0.0 0.0 TAFMER .RTM. DF-110 0.0 0.0 0.0 0.0 11.1 TAFMER .RTM.
DF-605 0.0 0.0 0.0 0.0 16.7 EVA-659 0.0 0.0 0.0 0.0 0.0 EVA-3330
0.0 0.0 0.0 0.0 0.0 ELVAX .RTM. 360 60.0 60.0 60.0 60.0 0.0 ZnO 1.0
ST/AC 1.0 TAC-GR50 0.3 D600MT 8.9 DCP 0.0 101-45GE 0.9 Total Parts
by Wt. 120.7 120.7 120.7 120.7 112.0 Composition F G H I J PFBC 1
(MB1) 0.0 0.0 0.0 0.0 0.0 PFBC 2 (MB2) 90.0 70.0 100.0 50.0 80.0
Kraton G1651E 0.0 0.0 0.0 0.0 0.0 TUFTEC .RTM. P1083 11.9 9.3 13.2
6.6 10.6 TUFTEC .RTM. JT-83 10.0 10.0 0.0 10.0 0.0 TUFTEC .RTM.
P5051 0.0 0.0 0.0 20.0 0.0 INFUSE .TM. 9000 OBC 0.0 0.0 0.0 0.0 0.0
INFUSE .TM. 9107 OBC 17.9 13.9 19.9 9.9 15.9 INFUSE .TM. 9530 OBC
0.0 20.0 0.0 20.0 20.0 ENGAGE .RTM. 8440 0.0 0.0 0.0 0.0 0.0 ENGAGE
.RTM. 8480 0.0 0.0 0.0 0.0 0.0 ENGAGE .RTM. 8540 0.0 0.0 0.0 0.0
0.0 TAFMER .RTM. DF-110 14.3 11.1 15.9 7.9 12.7 TAFMER .RTM. DF-605
21.5 16.7 23.8 11.9 19.1 EVA-659 0.0 0.0 0.0 0.0 0.0 EVA-3330 0.0
0.0 0.0 0.0 0.0 ELVAX .RTM. 360 0.0 0.0 0.0 0.0 0.0 ZnO 1.0 1.0 1.0
1.0 1.0 ST/AC 1.0 1.0 1.0 1.0 1.0 TAC-GR50 0.2 0.4 0.4 0.3 0.4
D600MT 10.0 8.9 15.2 8.9 4.7 DCP 0.4 0.0 0.0 0.0 0.0 101-45GE 0.9
0.8 0.8 0.9 0.8 Total Parts by Wt. 113.5 112.1 118.4 112.0 107.9
Composition K L M N O PFBC 1 (MB1) 0.0 0.0 0.0 0.0 0.0 PFBC 2 (MB2)
60.0 80.0 100.0 100.0 70.0 Kraton G1651E 0.0 0.0 0.0 0.0 0.0 TUFTEC
.RTM. P1083 7.9 10.6 13.2 13.2 9.3 TUFTEC .RTM. JT-83 0.0 0.0 0.0
0.0 10.0 TUFTEC .RTM. P5051 0.0 0.0 0.0 0.0 0.0 INFUSE .TM. 9000
OBC 0.0 0.0 0.0 0.0 20.0 INFUSE .TM. 9107 OBC 11.9 15.9 19.9 19.9
13.9 INFUSE .TM. 9530 OBC 40.0 20.0 0.0 0.0 0.0 ENGAGE .RTM. 8440
0.0 0.0 0.0 0.0 0.0 ENGAGE .RTM. 8480 0.0 0.0 0.0 0.0 0.0 ENGAGE
.RTM. 8540 0.0 0.0 0.0 0.0 0.0 TAFMER .RTM. DF-110 9.5 12.7 15.9
15.9 11.1 TAFMER .RTM. DF-605 14.3 19.1 23.8 23.8 16.7 EVA-659 0.0
0.0 0.0 0.0 0.0 EVA-3330 0.0 0.0 0.0 0.0 0.0 ELVAX .RTM. 360 0.0
0.0 0.0 0.0 0.0 ZnO 1.0 1.0 1.0 1.0 1.0 ST/AC 1.0 1.0 1.0 1.0 1.0
TAC-GR50 0.4 0.4 0.4 0.4 0.3 D600MT 4.4 8.6 5.0 8.6 8.9 DCP 0.0 0.0
0.0 0.0 0.0 101-45GE 0.8 0.8 0.8 0.8 0.9 Total Parts by Wt. 107.6
111.8 108.2 111.8 112.0 Composition P Q R S T PFBC 1 (MB1) 0.0 0.0
0.0 0.0 0.0 PFBC 2 (MB2) 70.0 100.0 60.0 70.0 100.0 Kraton G1651E
0.0 0.0 0.0 0.0 0.0 TUFTEC .RTM. P1083 9.3 13.2 7.9 9.3 13.2 TUFTEC
.RTM. JT-83 10.0 0.0 0.0 10.0 0.0 TUFTEC .RTM. P5051 0.0 0.0 0.0
0.0 0.0 INFUSE .TM. 9000 OBC 0.0 0.0 0.0 0.0 0.0 INFUSE .TM. 9107
OBC 13.9 19.9 11.9 13.9 19.9 INFUSE .TM. 9530 OBC 20.0 0.0 40.0
20.0 0.0 ENGAGE .RTM. 8440 0.0 0.0 0.0 0.0 0.0 ENGAGE .RTM. 8480
0.0 0.0 0.0 0.0 0.0 ENGAGE .RTM. 8540 0.0 0.0 0.0 0.0 0.0 TAFMER
.RTM. DF-110 11.1 15.9 9.5 11.1 15.9 TAFMER .RTM. DF-605 16.7 23.8
14.3 16.7 23.8 EVA-659 0.0 0.0 0.0 0.0 0.0 EVA-3330 0.0 0.0 0.0 0.0
0.0 ELVAX .RTM. 360 0.0 0.0 0.0 0.0 0.0 ZnO 1.0 1.0 1.0 1.0 1.0
ST/AC 1.0 1.0 1.0 1.0 1.0 TAC-GR50 0.3 0.4 0.4 0.4 0.4 D600MT 8.6
8.8 8.3 8.9 15.2 DCP 0.0 0.0 0.0 0.0 0.0 101-45GE 0.9 0.8 0.8 0.8
0.8 Total Parts by Wt. 111.8 116.5 111.5 112.1 118.4 Composition U
V' W' PFBC 1 (MB1) 100.0 100.0 100.0 PFBC 2 (MB2) 0.0 0.0 0.0
Kraton G1651E 0.0 0.0 0.0 TUFTEC .RTM. P1083 8.0 8.0 8.0 TUFTEC
.RTM. JT-83 0.0 0.0 0.0 TUFTEC .RTM. P5051 0.0 0.0 0.0 INFUSE .TM.
9000 OBC 0.0 0.0 0.0 INFUSE .TM. 9107 OBC 12.0 12.0 12.0 INFUSE
.TM. 9530 OBC 0.0 0.0 0.0 ENGAGE .RTM. 8440 0.0 0.0 0.0 ENGAGE
.RTM. 8480 0.0 0.0 0.0 ENGAGE .RTM. 8540 0.0 0.0 0.0 TAFMER .RTM.
DF-110 9.6 9.6 9.6 TAFMER .RTM. DF-605 14.4 14.4 14.4 EVA-659 31.9
31.9 31.9 EVA-3330 4.0 4.0 4.0 ELVAX .RTM. 360 0.0 0.0 0.0 ZnO 1.0
1.0 1.0 ST/AC 1.0 1.0 1.0 TAC-GR50 0.4 1.0 0.6 D600MT 8.8 8.4 7.9
DCP 0.0 0.0 0.0 101-45GE 0.8 0.2 0.6 Total Parts by Wt. 112.0 111.6
111.1
Example 2: Continuous Process of Preparing Pre-Foam
Compositions
[0176] Pre-foam compositions can be prepared using a continuous
process where the styrenic copolymer component and the unsaturated
olefin component are pre-mixed in a hopper and fed into a
twin-screw extruder. The zone in the twin-screw extruder into which
the styrenic copolymer component and the unsaturated olefin
component are fed (ZONE 1) is held at a temperature of from about
100.degree. C. to about 120.degree. C. When included in the
pre-foam composition, the optional EVA component and/or pigments
are pre-mixed with the styrenic copolymer component and the
unsaturated olefin component.
[0177] Next, one or more metal oxide, one or more organic acid, and
one or more crosslinking agent are added to the mixture of polymer
and unsaturated olefin The particle size of the metal oxide used
was less than 1 micron. The combined mixture of the styrenic
copolymer component, the unsaturated olefin component, the optional
EVA component, and the metal oxide, organic acid, and crosslinking
agent are mixed in ZONE 1 of the twin-screw extruder at a
temperature of from about 100.degree. C. to about 120.degree. C.
until thoroughly mixed.
[0178] The combined mixture of the styrenic copolymer component,
the, unsaturated olefin component, the optional EVA component, and
the metal oxide, organic acid, and crosslinking agent move to ZONE
2 of the twin-screw extruder, where the temperature is about
90.degree. C. or below. The combined mixture of the styrenic
copolymer component, the unsaturated olefin component, the EVA
component, and the metal oxide, organic acid, and crosslinking
agent are then combined in ZONE 2 with a blowing agent and a free
radical initiator.
[0179] Next, the mixture of the styrenic copolymer component, the
unsaturated olefin component, the optional EVA component, and the
metal oxide, organic acid, crosslinking agent, blowing agent, and
free radical initiator is then subjected to pelletization using a
die that is cooled to maintain the temperature at about 90.degree.
C. or below. The pelletization can performed under water, thus
cooling the resulting pellets as they exit the pelletization
die.
Example 3: Forming Foam Articles from Pre-Foam Compositions
[0180] Pellets made according to the batch process described in
Examples 1 using the pre-foam composition formulations described in
Tables 1-4 were injection molded (IM) into a pre-heated mold where
the mold temperature was, from about 170.degree. C. to about
180.degree. C. The mold temperature was above the decomposition
temperature of the chemical blowing agent, which decomposed
producing gas in the softened composition and foaming it. The mold
temperature was also above the initiation temperature of the
free-radical initiator, producing a polymerization reaction which
crosslinked the unsaturated styrenic copolymer component with the
unsaturated olefin component of the composition.
[0181] As indicated in Table 5, some of the pre-foam compositions
were foamed and injection molded in a single-step process (IM) to
produce the finished molded foam article without a compression
molding step, while other pre-foam compositions were foamed and
molded using a process in which the pre-foam composition was first
injection molded to form a molded foam pre-foam, then the molded
foam pre-form was annealed, and then the annealed molded foam
pre-form was compression molded to produce the finished molded foam
article (IM+CM).
[0182] For the pre-foam compositions which were injection molded
and subsequently compression molded to produce the finished molded
foam articles (IM+CM), the injection molded foam preform was taken
through an annealing process in which the foam preform was heated
to a temperature of about 70.degree. C. to about 80.degree. C. for
about 10 to about 15 minutes; then cooled to a temperature of about
60.degree. C. to about 70.degree. C. and held at that temperature
for about 10 to about 15 minutes; next the preform was cooled to a
temperature of about 50.degree. C. to about 60.degree. C. and held
at that temperature for about 10 to about 15 minutes; then cooled
to a temperature of about 45.degree. C. to about 55.degree. C. and
held at that temperature for about 10 to about 15 minutes. The
annealed molded foam preform was then washed with water (about
35.degree. C. to about 40.degree. C.) for about 10 to about 15
minutes and subsequently dried for 24 hours.
[0183] The annealed molded foam preform was then placed in a
compression mold which is at least 10% smaller at least one
dimension relative to its initial foamed, molded and annealed state
prior to the compression molding. During the compression molding
process, the foam preform is heated to a surface temperature of
from about 130.degree. C. to about 150.degree. C. Then the foam
preform is cooled to a surface temperature of about 30.degree. C.
in about 15 minutes or less (e.g., in about 12 minutes or less) to
give a finished compression molded foam article.
[0184] While this experiment used the pre-foam compositions only to
produce injection molded foam articles (IM) and injection molded
and compression molded foam articles (IM+CM) using the processes
described above, the pre-foam compositions described herein can be
foamed and/or molded using other types of processes known in the
art. For example, these pre-foam compositions can be used to form
slab foam, particulate (e.g., bead) foams, etc. These forms of foam
can then be used in various ways. For example, slab foam can be
formed, and then can be used as formed as a final component, or can
be compression molded to form a final component. Pellets of the
pre-foam compositions can be used to form individual particulate
foams, or can be foamed and molded to form molded foam
articles.
TABLE-US-00004 TABLE 4 Compositions and Component Ratios for Foams
Composition A B C D E Aromatic/Aliphatic Block 20.0 20.0 20.0 20.0
19.3 Copolymer (Parts by Wt.) Olefinic Copolymer (Parts 20.0 20.0
20.0 20.0 33.9 by Wt.) Linking Polymer (Parts by 0.0 0.0 0.0 0.0
27.8 Wt.) EVA Copolymer (Parts by 0.0 0.0 0.0 0.0 0.0 Wt.) Resin
Component (Parts 40.0 40.0 40.0 40.0 81.0 by Wt.) Component Ratios
I: Olefinic Copolymer 1.00 1.00 1.00 1.00 1.76 (Parts by Wt.) to
Aromatic/Aliphatic Block Copolymer (Parts by Wt.) II: Linking
Polymer (Parts 0.00 0.00 0.00 0.00 1.44 by Wt.) to
Aromatic/Aliphatic Block Copolymer (Parts by Wt.) III: EVA
Copolymer (Parts 0.00 0.00 0.00 0.00 0.00 by Wt.) to
Aromatic/Aliphatic Block Copolymer (Parts by Wt.) IV: Linking
Polymer (Parts 0.00 0.00 0.00 0.00 0.82 by Wt.) to Olefinic
Copolymer (Parts by Wt.) V: EVA Copolymer (Parts 0.00 0.00 0.00
0.00 0.00 by Wt.) to Olefinic Copolymer (Parts by Wt.) VI: EVA
Copolymer (Part N/A N/A N/A N/A 0.00 by Wt.) to Linking Polymer
(Parts by Wt.) Sum of Ratios I-V 1.00 1.00 1.00 1.00 3.20 Sum of
Ratios I-VI* N/A N/A N/A N/A 4.02 Composition F G H I J
Aromatic/Aliphatic Block 21.9 19.3 13.2 36.6 10.6 Copolymer (Parts
by Wt.) Olefinic Copolymer (Parts 17.9 33.9 19.9 29.9 35.9 by Wt.)
Linking Polymer (Parts by 35.7 27.8 39.7 19.9 31.8 Wt.) EVA
Copolymer (Parts by 0.0 0.0 0.0 0.0 0.0 Wt.) Resin Component (Parts
75.5 81.0 72.8 86.4 78.2 by Wt.) Component Ratios I: Olefinic
Copolymer 0.82 1.76 1.50 0.82 3.39 (Parts by Wt.) to
Aromatic/Aliphatic Block Copolymer (Parts by Wt.) II: Linking
Polymer (Parts 1.63 1.44 3.00 0.54 3.00 by Wt.) to
Aromatic/Aliphatic Block Copolymer (Parts by Wt.) III: EVA
Copolymer (Parts 0.00 0.00 0.00 0.00 0.00 by Wt.) to
Aromatic/Aliphatic Block Copolymer (Parts by Wt.) IV: Linking
Polymer (Parts 2.00 0.82 2.00 0.66 0.89 by Wt.) to Olefinic
Copolymer (Parts by Wt.) V: EVA Copolymer (Parts 0.00 0.00 0.00
0.00 0.00 by Wt.) to Olefinic Copolymer (Parts by Wt.) VI: EVA
Copolymer (Part 0.00 0.00 0.00 0.00 0.00 by Wt.) to Linking Polymer
(Parts by Wt.) Sum of Ratios I-V 2.45 3.20 4.50 1.36 6.39 Sum of
Ratios I-VI* 4.45 4.02 6.50 2.02 7.28 Composition K L M N O
Aromatic/Aliphatic Block 7.9 10.6 13.2 13.2 19.3 Copolymer (Parts
by Wt.) Olefinic Copolymer (Parts 51.9 35.9 19.9 19.9 13.9 by Wt.)
Linking Polymer (Parts by 23.8 31.8 39.7 39.7 27.8 Wt.) EVA
Copolymer (Parts by 0.0 0.0 0.0 0.0 0.0 Wt.) Resin Component (Parts
83.7 78.2 72.8 72.8 61.0 by Wt.) Component Ratios I: Olefinic
Copolymer 6.54 3.39 1.50 1.50 0.72 (Parts by Wt.) to
Aromatic/Aliphatic Block Copolymer (Parts by Wt.) II: Linking
Polymer (Parts 3.00 3.00 3.00 3.00 1.44 by Wt.) to
Aromatic/Aliphatic Block Copolymer (Parts by Wt.) III: EVA
Copolymer (Parts 0.00 0.00 0.00 0.00 0.00 by Wt.) to
Aromatic/Aliphatic Block Copolymer (Parts by Wt.) IV: Linking
Polymer (Parts 0.46 0.89 2.00 2.00 2.00 by Wt.) to Olefinic
Copolymer (Parts by Wt.) V: EVA Copolymer (Parts 0.00 0.00 0.00
0.00 0.00 by Wt.) to Olefinic Copolymer (Parts by Wt.) VI: EVA
Copolymer (Part 0.00 0.00 0.00 0.00 0.00 by Wt.) to Linking Polymer
(Parts by Wt.) Sum of Ratios I-V 9.54 6.39 4.50 4.50 2.16 Sum of
Ratios I-VI* 10.00 7.28 6.50 6.50 4.16 Composition P Q R S T
Aromatic/Aliphatic Block 19.3 13.2 7.9 19.3 13.2 Copolymer (Parts
by Wt.) Olefinic Copolymer (Parts 33.9 19.9 51.9 33.9 19.9 by Wt.)
Linking Polymer (Parts by 27.8 39.7 23.8 27.8 39.7 Wt.) EVA
Copolymer (Parts by 0.0 0.0 0.0 0.0 0.0 Wt.) Resin Component (Parts
81.0 72.8 83.7 81.0 72.8 by Wt.) Component Ratios I: Olefinic
Copolymer 1.76 1.50 6.54 1.76 1.50 (Parts by Wt.) to
Aromatic/Aliphatic Block Copolymer (Parts by Wt.) II: Linking
Polymer (Parts 1.44 3.00 3.00 1.44 3.00 by Wt.) to
Aromatic/Aliphatic Block Copolymer (Parts by Wt.) III: EVA
Copolymer (Parts 0.00 0.00 0.00 0.00 0.00 by Wt.) to
Aromatic/Aliphatic Block Copolymer (Parts by Wt.) IV: Linking
Polymer (Parts 0.82 2.00 0.46 0.82 2.00 by Wt.) to Olefinic
Copolymer (Parts by Wt.) V: EVA Copolymer (Parts 0.00 0.00 0.00
0.00 0.00 by Wt.) to Olefinic Copolymer (Parts by Wt.) VI: EVA
Copolymer (Part 0.00 0.00 0.00 0.00 0.00 by Wt.) to Linking Polymer
(Parts by Wt.) Sum of Ratios I-V 3.20 4.50 9.54 3.20 4.50 Sum of
Ratios I-VI* 4.02 6.50 10.00 4.02 6.50 Composition U V' W'
Aromatic/Aliphatic Block 8.0 8.0 8.0 Copolymer (Parts by Wt.)
Olefinic Copolymer (Parts 12.0 12.0 12.0 by Wt.) Linking Polymer
(Parts by 23.9 23.9 23.9 Wt.) EVA Copolymer (Parts by 35.9 35.9
35.9 Wt.) Resin Component (Parts 79.8 79.8 79.8 by Wt.) Component
Ratios I: Olefinic Copolymer 1.50 1.50 1.50 (Parts by Wt.) to
Aromatic/Aliphatic Block Copolymer (Parts by Wt.) II: Linking
Polymer (Parts 3.00 3.00 3.00 by Wt.) to Aromatic/Aliphatic Block
Copolymer (Parts by Wt.) III: EVA Copolymer (Parts 4.50 4.50 4.50
by Wt.) to Aromatic/Aliphatic Block Copolymer (Parts by Wt.) IV:
Linking Polymer (Parts 2.00 2.00 2.00 by Wt.) to Olefinic Copolymer
(Parts by Wt.) V: EVA Copolymer (Parts 3.00 3.00 3.00 by Wt.) to
Olefinic Copolymer (Parts by Wt.) VI: EVA Copolymer (Part 1.50 1.50
1.50 by Wt.) to Linking Polymer (Parts by Wt.) Sum of Ratios I-V
4.50 4.50 4.50 Sum of Ratios I-VI* 15.50 15.50 15.50 NT: not tested
N/A: not applicable
Example 4: Testing of Foam Articles
[0185] Examples of foam articles formed from the formulations
described in Tables 3 and 4 were made and tested to determine their
physical properties (e.g., specific gravity, hardness, split tear,
compression set, and energy return). The results for foam articles
for the various formulations are reported in Table 5.
[0186] The purpose of this experiment was to identify pre-foam
compositions with improved split-tear values as compared to
conventional ethylene vinyl acetate (EVA) foam, but which otherwise
maintained the physical properties of conventional EVA foam which
are beneficial for us as components of articles of footwear. The
experimental pre-foam compositions were based on using a styrenic
copolymer component, an unsaturated olefin component, and
optionally an EVA component. Some of the formulations were used to
produce foams which were first injection molded and then annealed
and compression molded to produce a final foam component (IM+CM),
while other formulations were used to produce foams which were
injection molded to produce a final foam component (IM). The target
range for the split-tear values was from about 2.5 kg/cm to about
3.0 kg/cm or greater. As a comparison, the split tear value for
conventional EVA foam is about 1.7. The target ranges for the other
physical properties of the final foam component were: a specific
gravity of about 0.1 to about 0.2; an Asker C hardness of about 40
to about 50; a compression set of about 20% to about 35%; and a
resilience of at least about 60%. These target ranges were based
primarily on the physical properties of conventional EVA foam used
as components for article of footwear, which has a specific gravity
of from 0.080 to 0.095, an Asker C hardness of 34-38, a compression
set of 75%, and an resiliency of about 59.
[0187] The test method used to obtain the specific gravity values
reported in Table 5 is as follows.
[0188] The specific gravity of the foam was be determined by
testing 3 representative samples taken from a foam preform or
compression molded foam component. Using a balance with appropriate
accuracy for the weight of the sample, the weight of each sample
was determined both in air and when the sample was completely
submerged in distilled water at a temperature of 22.degree.
C..+-.2.degree. C., after removing any air bubbles adhered to the
surface of the foam sample before weighing. The specific gravity
(S.G.) was then calculated by taking the weight of the sample in
water and subtracting that from the weight of the sample in air,
and this value was then divided into the weight of the sample in
air, where all the weights are weights in grams.
[0189] Split Tear Test
[0190] The test method used to obtain the split tear values for
foam articles as shown in Table 5 is as follows.
[0191] Four die-cut, rectangular-shaped samples of slab sheet or
molded foam were prepared, each measuring 2.54 cm.times.15.24
cm.times.10.+-.1 mm (thickness). If the foam material to be tested
had a skin, the material had its skin removed before preparing the
four samples. A 3 cm long cut was made in the center from one end
of the sample. Then five successive 2 cm portions were marked on
the sample.
[0192] The crosshead speed of the tensile test apparatus was set at
50 mm/min. Each separated end of the sample was clamped in an upper
grip and a lower grip of the test apparatus. The separation was
placed in the middle between both grips. Each section of the sample
was held in a clamp in such a manner that the original adjacent cut
edges formed a straight line joining the centers of the clamps.
[0193] As needed, the cut was aided with a sharp knife to keep
separating the foam material in the center of the sample. Readings
caused by cutting with the knife were discarded. The lowest values
for each of the five portions of each sample were recorded in
kg/cm. Five values were recorded for each sample and an average of
the five values was then obtained and reported. If a portion of a
sample included a portion having an air bubble more than 2 mm in
diameter, the value for the portion including the air bubble was
not included in the average. If more than one portion of a sample
was found to include air bubbles having a diameter greater than 2
mm, another sample was then tested.
[0194] Durometer Hardness Test
[0195] The test used to obtain the hardness values for the foam
articles reported in Table 5 is as follows.
[0196] For flat foams, the sample was a minimum of 6 mm thick for
Asker C durometer testing. If necessary, foam samples were stacked
to make up the minimum thickness. Foam samples were large enough to
allow all measurements to be performed at a minimum of 12 mm from
the edge of the sample and at least 12 mm from any other
measurement. Regions tested were flat and parallel with an area at
least 6 mm in diameter. For the samples tested in Table 5, standard
samples having dimensions of approximately 35 cm.times.13
cm.times.1.8 cm, were used, and a minimum of five hardness
measurements were taken and tested using a 1 kg head weight.
[0197] Compression Set
[0198] The test used to obtain the compression set values for foam
articles reported in Table 5 is as follows.
[0199] A foam sample was compressed between two metal plates to 50%
of its original thickness and placed in an oven at 50.degree. C.
for 6 hours. The sample was then cooled and the difference between
its precompression and post-compression thickness was used as the
measure of static compression set.
[0200] For the tests reported in Table 5, molded plaques having
skin on one side and a thickness of 10 mm were used to obtain the
samples. The plaque was then skived to a thickness of 10+/-0.5 mm
to remove the skin before cutting the samples. Compression molded
foam materials having skin on two sides had the skin skived from
one side, so that skin remained on only one side. Five 2.54 cm
diameter circles were then machine drilled from the plaque to
obtain the samples to be tested.
[0201] The compression set testing device consists of two flat
steel plates set between the parallel faces of the compression
device with compression rings and spacer bars for each set of
parallel faces. Four compression rings of the same thickness (4.5
mm or 5.0 mm based on the specimen thickness) were used for each
parallel face of the compression device. The percent compression
set was calculated using the following equation:
% Set=((Original gauge-final gauge)/(50% Original
gauge)).times.100
[0202] The center area of each specimen was marked and used to
measure the specimens with the use of an AMES gage with no load on
top.
[0203] Enemy Return Test
[0204] The test used to obtain the energy return values for foam
articles reported in Table 5 is as follows.
[0205] Energy return of the foam articles was determined using ASTM
D 2632 92, which uses a vertical rebound apparatus.
TABLE-US-00005 TABLE 5 Processing Methods and Properties of Foam
Articles Composition A B C D E Processing Method Physical
Properties 2 2 2 2 2 IM Foam Specific Gravity 0.1185 0.1166 0.1171
0.1153 0.11 Hardness (Asker C) 32-33 33-34 32-33 28-30 41-42 Split
Tear (kg/cm) 1.79-1.75 1.61-1.78 1.58-1.62 1.52-1.56 1.3
Compression Set (%) 72-73 70-71 72-74 70-71 51-53 Energy Return
(slab) (%) NA IM + CM Foam Specific Gravity 0.2048 0.2089 0.2021
0.2042 0.16-0.17 Hardness (Asker C) 49-50 50-51 49-50 56-58 53-54
Split Tear (kg/cm) 2.7-2.8 2.6-2.8 2.8-2.9 2.4-2.5 2 Compression
Set (%) 43-45 39-40 49-50 38-39 21 Energy Return (slab) (%) 50-51
49-50 53-54 47-48 68 Composition F G H I J Processing Method
Physical Properties 2 2 1 2 2 IM Foam Specific Gravity 0.09 0.1
0.15 0.11 0.159 Hardness (Asker C) 32-34 34-35 52-53 43-45 50-51
Split Tear (kg/cm) 1.9 2 2.5-2.6 1.6 2.98-3.06 Compression Set (%)
71-72 74-76 35-55 69 49-51 Energy Return (slab) (%) 60 83-89 71 64
64-65 IM + CM Foam Specific Gravity 0.13-0.14 NT NA 0.18 NT
Hardness (Asker C) 43-48 NT NA 55-59 NT Split Tear (kg/cm) 2.3 NT
NA 2.5-2.6 NT Compression Set (%) 39-41 NT NA 21-22 NT Energy
Return (slab) (%) 68 NT NA 69 NT Composition K L M N O Processing
Method Physical Properties 2 1 2 1 2 IM Foam Specific Gravity 0.15
0.17 0.167 0.17 0.13 Hardness (Asker C) 46-48 54-55 52-54 54-55
42-44 Split Tear (kg/cm) 2.73-3.01 2.6-2.7 3.0-3.1 2.7-2.8 2
Compression Set (%) 59-61 26-32 43-46 28-33 71 Energy Return (slab)
(%) 67-72 69-70 61-63 69-72 65 IM + CM Foam Specific Gravity NT NA
NT NA 0.17-0.18 Hardness (Asker C) NT NA NT NA 54-57 Split Tear
(kg/cm) NT NA NT NA 3.0-3.1 Compression Set (%) NT NA NT NA 28
Energy Return (slab) (%) NT NA NT NA 69 Composition P Q R S T
Processing Method Physical Properties 2 1 1 1 1 IM Foam Specific
Gravity 0.11 0.17 0.16 0.15 0.11 Hardness (Asker C) 42-43 54-55
51-52 49-51 33-36 Split Tear (kg/cm) 2 3.4 2.6 2.8-3.0 1.4-1.7
Compression Set (%) 66-72 38-39 37-43 40-50 63-70 Energy Return
(slab) (%) NA 68 71-73 74-76 84-87 IM + CM Foam Specific Gravity
0.17 NA NA NA NA Hardness (Asker C) 52-55 NA NA NA NA Split Tear
(kg/cm) 3.1 NA NA NA NA Compression Set (%) 31-37 NA NA NA NA
Energy Return (slab) (%) 67-70 NA NA NA NA Composition U V' W'
Processing Method Physical Properties 1 1 1 IM Foam Specific
Gravity 0.18 0.19 0.19 Hardness (Asker C) 42-45 42-44 43-45 Split
Tear (kg/cm) 2.5-2.6 2.6-2.7 2.6 Compression Set (%) 29-33 32-34
31-32 Energy Return (slab) (%) 78-80 80 79-82 IM + CM Foam Specific
Gravity NA NA NA Hardness (Asker C) NA NA NA Split Tear (kg/cm) NA
NA NA Compression Set (%) NA NA NA Energy Return (slab) (%) NA NA
NA NT: not tested NA: not applicable 1: Pre-foam composition was
injection molded to form final foam article and then the foam
preform 2: Pre-foam composition was injection molded to form foam
preform, was compression molded to form final foam article
[0206] Results
[0207] Four of the 13 final molded foam articles produced using
injection molding and compression molding (IM+CM) had split tear
values of greater than 2.5, and 8 of the 11 final molded foam
articles produced using just the injection molding process (IM) had
split tear values of greater than 2.5. Unexpectedly, 12 of the
formulations which produced molded foam articles with the target
split tear values also had resiliency values significantly higher
than expected. Specifically, formulations H, I, L, N, O, P, Q, R,
S, U, V and X had resiliency values ranging from 67% to 82%.
However, only 2 pre-foam compositions were found which produced
final foam components having all their physical properties in the
target ranges (formulations U and X). The resiliency values for
these two formulations were found to be over 14 percentage points
greater than for conventional EVA foam.
[0208] In general, the pre-foam compositions which produced final
foam components with unexpectedly high resiliency values included
from about 10 parts per hundred of resin (phr) to about 22 phr of
the styrenic copolymer component, and from about 45 phr to about 80
phr of the unsaturated olefin component. Some of these pre-form
compositions also comprised from about 31 phr to about 36 phr of
the EVA component, while others were free of the EVA component.
Generally, the pre-foam compositions which produced final foam
components with target split tear values and unexpectedly high
resiliency values had ratios of the phr of the styrenic copolymer
component to the phr of the unsaturated olefin component which
ranged from about 0.17 to about 0.30. For the pre-foam compositions
including an EVA component, the ratios of the phr of the styrenic
copolymer component to the phr of the EVA component ranged from
about 0.37 to about 0.70. The ratios of the phr of the unsaturated
olefin component to the phr of the EVA component ranged from about
2.2 to about 2.3. For the pre-foam compositions including an EVA
component, the sum of all three ratios ranged from about 2.7 to
about 3.3.
[0209] It should be emphasized that the above-described aspects of
the present disclosure are merely possible examples of
implementations, and are set forth only for a clear understanding
of the principles of the disclosure. Many variations and
modifications may be made to the above-described aspects of the
disclosure without departing substantially from the spirit and
principles of the disclosure. All such modifications and variations
are intended to be included herein within the scope of this
disclosure.
[0210] The present disclosure will be better understood upon review
of the following clauses, which should not be confused with the
claims.
1. A composition comprising: an A-B-A block copolymer, wherein each
of the A blocks comprise repeat units according to the following
formula
##STR00003##
[0211] where each occurrence of R.sup.1 is independently a
hydrogen, halogen, hydroxyl, or a substituted or unsubstituted
alkyl group having from 1 to 18 carbon atoms,
[0212] where each occurrence of R.sup.2 is independently none or a
substituted or unsubstituted alkyl group having from 1 to 8 carbon
atoms,
[0213] wherein the B block is a random copolymer of ethylene and a
first alpha-olefin, wherein the first alpha olefin has 3 to 8
carbon atoms;
[0214] and wherein the A-B-A-block copolymer comprises about 10% to
about 40% of the A blocks by weight based upon an entire weight of
the A-B-A block copolymer;
[0215] an olefinic block copolymer, wherein the olefinic block
copolymer is a copolymer of ethylene and a second alpha-olefin,
wherein the second alpha-olefin has 6 to 12 carbon atoms, and
wherein the olefinic block copolymer has one or more blocks rich in
the ethylene and one or more blocks rich in the second
alpha-olefin; and
[0216] an alpha-olefin linking polymer, wherein the alpha-olefin
linking polymer is a copolymer of ethylene and a third
alpha-olefin, wherein the third alpha-olefin has 3 to 18 carbon
atoms;
[0217] wherein a ratio II of a total parts by weight of the A-B-A
block copolymer present in the composition to a total parts by
weight of the linking polymer present in the is from about 1.00 to
about 5.00.
2. The composition according to clause 1, wherein the ratio II is
from about 1.50 to about 4.00. 3. A composition comprising: an
A-B-A block copolymer, wherein each of the A blocks comprise repeat
units according to the following formula
##STR00004##
[0218] where each occurrence of R.sup.1 is independently a
hydrogen, halogen, hydroxyl, or a substituted or unsubstituted
alkyl group having from 1 to 18 carbon atoms,
[0219] where each occurrence of R.sup.2 is independently none or a
substituted or unsubstituted alkyl group having from 1 to 8 carbon
atoms,
[0220] wherein the B block is a random copolymer of ethylene and a
first alpha-olefin, wherein the first alpha-olefin has about 3 to 8
carbon atoms;
[0221] and wherein the A-B-A-block copolymer comprises about 10% to
about 40% of the A blocks by weight based upon an entire weight of
the A-B-A block copolymer;
[0222] an olefinic block copolymer, wherein the olefinic block
copolymer is a copolymer of ethylene and a second alpha-olefin,
wherein the second alpha-olefin has 6 to 12 carbon atoms, and
wherein the olefinic block copolymer has one or more blocks rich in
the ethylene and one or more blocks rich in the second
alpha-olefin; and
[0223] an alpha-olefin linking polymer, wherein the alpha-olefin
linking polymer is a copolymer of ethylene and a third
alpha-olefin, wherein the third alpha-olefin has 3 to 18 carbon
atoms.
4. The composition according to any one of clauses 1-3, wherein
each occurrence of R.sup.1 is a hydrogen or a substituted or
unsubstituted alkyl group having from 1 to 5 carbon atoms. 5. The
composition according to any one of clauses 1-3, wherein R.sup.2 is
none. 6. A composition comprising:
[0224] an A-B-A block copolymer, wherein each of the A blocks
comprise styrenic repeat units, the B block is a random copolymer
of ethylene and a first alpha-olefin, wherein the first
alpha-olefin has 3 to 8 carbon atoms, and wherein the A-B-A-block
copolymer comprises about 10% to about 40% of the A blocks by
weight based upon an entire weight of the A-B-A block
copolymer;
[0225] an olefinic block copolymer, wherein the olefinic block
copolymer is a copolymer of ethylene and a second alpha-olefin,
wherein the second alpha-olefin has 6 to 12 carbon atoms, and
wherein the olefinic block copolymer has one or more blocks rich in
the ethylene and one or more blocks rich in the second
alpha-olefin; and
[0226] an alpha-olefin linking polymer, wherein the alpha-olefin
linking polymer is a copolymer of ethylene and a third
alpha-olefin. Wherein the third alpha-olefin has 3 to 18 carbon
atoms, and wherein the alpha-olefin linking polymer has an
alpha-olefin monomer content of about 15% to about 40% by weight
based upon an entire weight of the alpha-olefin linking
polymer.
7. The composition according to any one of clauses 1-3 and 6,
wherein the alpha-olefin linking polymer has an alpha-olefin
monomer content of about 15% to about 40% by weight based upon an
entire weight of the alpha-olefin linking polymer. 8. The
composition according to any one of clauses 1-3 and 6, wherein each
of the A blocks consists essentially of polystyrene. 9. The
composition according to any one of clauses 1-3 and 6, wherein the
B block consists essentially of a copolymer of ethylene and octene.
10. The composition according to any one of clauses 1-3 and 6,
wherein the B block consists essentially of a copolymer of ethylene
and butadiene. 11. The composition according to any one of clauses
1-3 and 6, wherein the composition comprises a first alpha-olefin
linking polymer and a second alpha-olefin linking polymer,
[0227] wherein the first alpha-olefin linking polymer and the
second alpha-olefin linking polymer are copolymers of ethylene and
1-butene, each having a different ratio of ethylene to 1-butene
monomer content in the copolymer.
12. The composition according to any one of clauses 1-3 and 6,
wherein the composition comprises about 5 parts by weight to about
15 parts by weight of the A-B-A block copolymer, about 10 parts by
weight to about 20 parts by weight of the olefinic block copolymer,
and about 25 parts by weight to about 35 parts by weight of the
alpha-olefin linking polymers based upon an entire weight of the
composition. 13. The composition according to any one of clauses
1-3 and 6, further comprising an ethylene-vinyl acetate copolymer
having a vinyl acetate content of about 10% to about 45% by weight
based upon the weight of the ethylene-vinyl acetate copolymer. 14.
The composition according to any one of clauses 1-3 and 6, wherein
the A-B-A block copolymer is at least partially or fully
hydrogenated. 15. The composition according to any one of clauses
1-3 and 6, wherein the A-B-A block copolymer has a degree of
hydrogenation of about 50% to about 80%. 16. The composition
according to any one of clauses 1-3 and 6, wherein the A-B-A block
copolymer has a degree of hydrogenation of at least 60% to about
80%. 17. A composition comprising:
[0228] a partially hydrogenated thermoplastic elastomeric block
copolymer, the partially hydrogenated thermoplastic elastomeric
block copolymer comprising:
[0229] one or more A blocks comprising aromatic repeat units,
[0230] one or more B blocks comprising aliphatic repeat units,
and
[0231] one or more first ethylenically unsaturated groups present
on one or both of the aromatic repeat units and the aliphatic
repeat units;
[0232] an olefinic block copolymer, wherein the olefinic block
copolymer is a copolymer of a first alpha-olefin and a second
alpha-olefin different from the first alpha-olefin, and wherein the
olefinic block copolymer comprising one or more second
ethylenically unsaturated groups; and
[0233] an alpha-olefin linking polymer, wherein the alpha-olefin
linking polymer comprises one or more aliphatic sidechains.
18. A composition comprising:
[0234] one or more partially hydrogenated thermoplastic elastomeric
block copolymers, each of the one or more partially hydrogenated
thermoplastic elastomeric block copolymers independently comprising
one or more aromatic blocks, one or more aliphatic blocks, and one
or more first ethylenically unsaturated units;
[0235] one or more olefinic block copolymers, each of the one or
more olefinic block copolymers comprising second ethylenically
unsaturated units; and
[0236] one or more alpha-olefin linking copolymers.
19. The composition according to clause 17 or clause 18, further
comprising one or more ethylene-vinyl acetate copolymers. 20. The
composition according to clause 17 or clause 18, wherein the
partially hydrogenated thermoplastic elastomeric block copolymer
comprises an A-B block structure or an A-B-A block structure,
[0237] wherein each of the A blocks comprise one or more aromatic
repeat units, and
[0238] wherein the B block is an aliphatic polymer block comprising
the one or more first ethylenically unsaturated units.
21. The composition according to clause 17 or clause 18, wherein
the partially hydrogenated thermoplastic elastomeric block
copolymer comprises about 10% to about 40% of the A block by weight
based upon an entire weight of the partially hydrogenated
thermoplastic elastomeric block copolymer. 22. The composition
according to clause 17 or clause 18, wherein the aromatic repeat
units comprise styrenic repeat units. 23. The composition according
to clause 17 or clause 18, wherein the aromatic repeat units
comprise an aliphatic backbone having a plurality of aromatic side
chains. 24. The composition according to clause 17 or clause 18,
wherein the aliphatic repeat units comprise one or more substituted
or unsubstituted alkyl side chains having about 2 to 10 carbon
atoms. 25. The composition according to any one of clauses 1-3, 6,
17, and 18, wherein the olefinic block copolymer is a copolymer of
ethylene and the second alpha-olefin. 26. The composition according
to clause 17 or clause 18, wherein the second alpha-olefin has
about 6 to 12 carbon atoms. 27. The composition according to clause
17 or clause 18, wherein the olefinic block copolymer has one or
more blocks rich in the first alpha-olefin and one or more blocks
rich in the second alpha-olefin 28. The composition according to
any one of clauses 1-3, 6, 17, and 18, wherein the composition
comprises about 5 parts by weight to about 20 parts by weight of
the A-B-A block copolymer or partially hydrogenated thermoplastic
elastomeric block copolymer based upon an entire weight of the
composition. 29. The composition according to any one of clauses
1-3, 6, 17, and 18, wherein the composition comprises about 5 parts
by weight to about 10 parts by weight of the A-B-A block copolymer
or partially hydrogenated thermoplastic elastomeric block copolymer
based upon an entire weight of the composition. 30. The composition
according to any one of clauses 1-3, 6, 17, and 18, wherein the
composition comprises about 5 parts by weight to about 20 parts by
weight of the olefinic block copolymer by weight based upon an
entire weight of the composition. 31. The composition according to
any one of clauses 1-3, 6, 17, and 18, wherein the composition
comprises about 10 parts by weight to about 15 parts by weight of
the olefinic block copolymer by weight based upon an entire weight
of the composition. 32. The composition according to any one of
clauses 1-3, 6, 17, and 18, wherein the composition comprises about
15 parts by weight to about 35 parts by weight of the alpha-olefin
linking polymer based upon an entire weight of the composition. 33.
The composition according any one of clauses 1-3, 6, 17, and 18,
wherein the composition comprises about 20 parts by weight to about
30 parts by weight of the alpha-olefin linking polymer based upon
an entire weight of the composition. 34. The composition according
to clause 19, wherein the composition comprises about 20 parts by
weight to about 45 parts by weight of the ethylene-vinyl acetate
copolymer based upon an entire weight of the composition. 35. The
composition according to clause 19, wherein the composition
comprises about 30 parts by weight to about 40 parts by weight of
the ethylene-vinyl acetate copolymer based upon an entire weight of
the composition. 36. The composition according to any one of
clauses 1-3, 6, 17, and 18, further comprising one or both of a
free-radical initiator and a chemical blowing agent. 37. The
composition according to clause 36, wherein the free-radical
initiator is selected from the group consisting of dicumyl
peroxide; n-butyl-4,4-di(t-butylperoxy) valerate;
1,1-di(t-butylperoxy)3,3,5-trimethylcyclohexane;
2,5-dimethyl-2,5-di(t-butylperoxy) hexane; di-t-butyl peroxide;
di-t-amyl peroxide; t-butyl peroxide; t-butyl cumyl peroxide;
2,5-dimethyl-2,5-di(tbutylperoxy)hexyne-3;
di(2-t-butyl-peroxyisopropyl)benzene; dilauroyl peroxide; dibenzoyl
peroxide; t-butyl hydroperoxide; and a combination thereof. 38. The
composition according to clause 36, wherein the composition
comprises a free-radical initiator selected from the group
consisting of a peroxide, a diazo compound, and a combination
thereof. 39. The composition according to clause 36, wherein the
composition comprises a chemical blowing agent selected from the
group consisting of a carbonate, bicarbonate, carboxylic acid, azo
compound, isocyanate, persulfate, peroxide, and a combination
thereof. 40. The composition according to any one of clauses 1-3,
6, 17, and 18, wherein the composition comprises about 5 parts by
weight to about 10 parts by weight of the A-B-A block copolymer or
partially hydrogenated thermoplastic elastomeric block copolymer
based upon an entire weight of the composition. 41. The composition
according to any one of clauses 1-3, 6, 17, and 18, wherein the
composition is a pre-foam composition. 42. A composition made by a
process of partially crosslinking the composition according to any
one of clauses 1-41. 43. The composition according to clause 42,
wherein the partially crosslinked composition has a degree of
crosslinking from about 50% to about 99%. 44. A composition
comprising a crosslinked reaction product of a composition
according to any one of clauses 1-41, wherein the composition is a
foamed composition. 45. A composition made by a process comprising
crosslinking and foaming a composition according to any one of
clauses 1-41. 46. The composition according to clause 45, wherein
the crosslinking and foaming steps occur at about the same time.
47. The composition according to clause 45 or clause 46, wherein
the process comprises injection molding the pre-foam composition
into an injection mold and crosslinking the pre-foam composition in
the injection mold. 48. The composition according to clause 47,
wherein the injection mold is at a temperature from about
150.degree. C. to about 190.degree. C. during the crosslinking. 49.
The composition according to any clause 48, wherein the composition
is compression molded to produce the foam composition. 50. The
composition according to clause 49, wherein the process further
comprises annealing the foam article and then compression molding
the foam article, reducing it in size by at least 10% in at least
one dimension relative to its initial foamed and molded state prior
to the compression molding. 51. The composition according to any
one of clauses 44-50, wherein the foam composition comprises a
degree of crosslinking from about 30% to about 90%. 52. The
composition according to any one of clauses 44-50, wherein the foam
composition has a specific density of about 0.08 to about 0.15. 53.
The composition according to any one of clauses 44-50, wherein the
foam composition has an energy return from about 60% to about 85%.
54. The composition according to any one of clauses 44-50, wherein
the foam composition has a split tear of about 1.6 kg/cm to about
4.0 kg/cm. 55. The composition according to any one of clauses
44-50, wherein the foam composition has a split tear of about 2.5
kg/cm to about 3.5 kg/cm. 56. The composition according to any one
of clauses 44-50, wherein the foam composition has an Asker C
hardness of about 40 to 60 C. 57. A method of making a foam
material, the method comprising foaming a composition according to
any one of clauses 1-58 to produce a foamed composition and
crosslinking the foamed composition to form the foam material. 58.
The methods according to clause 57, wherein the crosslinking and
foaming steps occur at about the same time. 59. The method
according to clause 57, comprising injection molding the pre-foam
composition into an injection mold to form the foamed composition
and crosslinking the foamed composition in the injection mold. 60.
The method of clause 59, wherein the injection mold is at a
temperature from about 150.degree. C. to about 190.degree. C.
during the crosslinking. 61. The method according to clause 59,
wherein the foamed composition is compression molded to produce the
foam material. 62. The method according to any clause 59, further
comprising annealing the foam material and then compression molding
the foam material, reducing it in size by at least 10% in at least
one dimension relative to its initial foamed and molded state prior
to compression molding. 63. A sole component for an article of
footwear, the sole component comprising a foam composition
according to any one of clauses 44-56. 64. A sole component for an
article of footwear, the sole component made by a by a process
comprising injection molding and crosslinking a pre-foam
composition according to any one of clauses 1-44 65. The sole
component according to clause 64, wherein the process further
comprises compression molding the crosslinked composition to
produce the sole component. 66. The sole component according to any
one of clauses 63-65, wherein the sole component is a midsole. 67.
The sole component according to any one of clauses 63-65, wherein
the sole component comprises a degree of crosslinking from about
30% to about 90%. 68. The sole component according to any one of
clauses 63-65, wherein the sole component has a specific density of
about 0.08 to about 0.15. 69. The sole component according to any
one of clauses 63-65, wherein the sole component has an energy
return from about 60% to about 85%. 70. The sole component
according to any one of clauses 63-65, wherein the sole component
has a split tear of about 1.6 kg/cm to about 4.0 kg/cm. 71. The
sole component according to any one of clauses 63-65, wherein the
sole component has a split tear of about 2.5 kg/cm to about 3.5
kg/cm. 72. The sole component according to any one of clauses
63-65, wherein the sole component has an Asker C hardness of about
40 to 60 C. 73. The sole component according to any one of clauses
63-65, wherein the article of footwear is a shoe. 74. The sole
component according to clause 73, wherein the shoe is selected from
the group consisting of an athletic shoe, a tennis shoe, a
cross-trainer shoe, a children's shoe, a dress shoe, and a casual
shoe. 75. An article of footwear comprising a sole component
according to any one of clauses 63-74. 76. The article of footwear
according to clause 75, wherein the sole component is a midsole,
and
[0239] wherein the article of footwear further comprises an upper
and an outsole.
77. The article of footwear according to clause 75, wherein the
article of footwear is a shoe. 78. The article of footwear
according to clause 77, wherein the shoe is selected from the group
consisting of an athletic shoe, a tennis shoe, a cross-trainer
shoe, a children's shoe, a dress shoe, and a casual shoe. 79. A
method of making an article of footwear, the method comprising
affixing a sole component according to any one of clauses 63-74 to
one or both of an upper and an outsole. 80. The composition
according to any one of clauses 3, 6, 17, and 18, wherein a ratio
II of a total parts by weight of the A-B-A block copolymer or the
partially hydrogenated thermoplastic elastomeric block copolymer
present in the composition to a total parts by weight of the
linking polymer present in the composition is from about 1.00 to
about 5.00. 81. The composition according to clause 80, wherein the
ratio II is from about 1.50 to about 4.00.
* * * * *