Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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FAB~IC-BACKED TELEBLOCK COPOLYMER COMPOSITION
ITH DULLED SURF~CE USEFUL I~ FOOTWE~R UPPERS
Background of the Invention
This invention relates to footwear. In one of its aspects
this inyention relates to material useful in preparing uppers for
footwear, In another of its aspects this invention relates to
laminated material. In yet another of its aspects this invention
relates to laminates of radial teleblock copolymer and fabric
backing~ In still another aspect of the invention it relates to
polymeric compositions with surfaces dulled to a suede-like finish.
PolyCvinylchloride~ compositions and other polymer-base
compositions are well-known in the art for use in footwear uppers.
Such compositions generally exhibit glossy surfaces and low air `
permeability or breathability. The present invention provides a
laminate composed of a polymeric composition having a dulled,
suede-like surface adhered to a fabric backing that is suitable,
because of its suede-like surface, not only for such leather-
subst~tute uses as ou~terwear and handbags; but~ because of the high
air permeability o~ ~reathability? is also useful, when bounded
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to an approp~iate soling material~ for use as uppers for shoes or
boots~
; 20 ~t :is therefo~e an ~b~ect of this invention to provide a
CO~positiQn suitable for coating a fabric backing to provide a
su~de~like su~f~ce ~or tbe 6acking~ It ~s anot~er ob~ect of tbe
invention to l~rovide a~laminate that is useful as a leather~
substitute, It is stlll another obJect of the invention to provide~
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a fabric~backed polymeric laminate suitable because of its high
air permeability fo~ use in footwear uppers.
Other aspects, ob~ects, and the various advantages of
this invention ~ill become apparent upon reading this specification
and the appended claim~,
State~ent of the Invention
In accordance with this invention~ a composition is pro-
vided suitable for coating of fabric backing to provide a suede-
like surface. In the composition a radial teleblock copolymer
is combined with a surface dulling agent
In an embodiment of the invention a laminate is provided
by adhering the surface dulled, radial teleblock copolymer composi-
tion described above to a fabric backing. In further embodiments
of the invention leather-substitute fabrlc and uppers for shoes
prepared from a laminate as described above are provided.
The radial teleblock copolymers useful in preparing the
inventive upper materials are of the formula (AB) Y wherein A
represents a block of poly(monovinylaromatic), B represents a
block of poly(conjugated diene), Y represents a residue of a
polyfunctional coupling agent or polyfunctional initiator and n
ls an integer having a value of 3 or more. A and B generally
represent pure homopolymer blocks~ but it is also within the
scope of this invention to include those block copolymers containing
the well known "tapered'l blocks.
Monovinyl-substituted aromatic monomers useful in the
prepar~tion of the A blocks of the above-described copolymers
generally contain from 8 to 12 carbon atoms per molecule. Examples
of such monomers include styrene~ 3-~ethyl-styrene, 4~n-propyl-
styrena, l~vinylnaphthalene, 2~vinylnaphthalene and the like.
Styrene is p~eferred,
Useful con~ugated dienes for the preparation of the B
blocks of the above-desc~lbed copolymers include thQse generally
containing fr~om 4 to 8 carhon ato~s per molecule. ExamRles of such
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monomers include 1?3-~utadiene, isoprene ? 1, 3~pentadieneg 2~4-
hexadiene? 3~ethyl~1~3-pentadiene, and the like~ 1l3-Butadlene
and isoprene are preferred.
The radial teleblock copolymers useful in this invention
are prepared using poly~unctional organolithium initiators or
polyfunctional coupling agents by well known methods described in
U~S. Patents 3~030,346? issued April 17~ 1962 to Richard N. Cooper,
Jr.; 3,351,905, issued November 7, 1967 to D. Kramer; 3,281,383,
issued October 25, 1966 to Robert P. Zelinski and Henry L. Hsieh;
and 3,639,521, issued February 1, 1972 to Henry L. Hsieh.
When Y is a residue of a polyfunctional coupling agent,
it is derived fro~ treating agents containing 3 or more, preferably
3 or 4, functional groups per molecule. Useful coupling agents
include multiepoxides, multiimines, multiisocyanates, multialdehydes,
multiketones, multiesters, multianhydrides and multihalides. SpeciEic
- examples of such agents include naphthalene-1?2,5,7-tetraiso-
cyanate, tri~l-aziridinyl) phosphine oxide, epoxidized soybean oil,
epoxidized linseed oil, 1,4,7-naphthalene tricarboxaldehyde, 1,4,9,10-
anthracenetetrone, pyromellitic dianhydride3 trimethyl tricarballylate,
and silicon tetrachloride.
When Y is a residue of a polyfunctional initiator it is
derived from compounds of g~neral formula R(Li) wherein x is an
integer of 3 or more, preferably 3 or 4 ? and R is an aliphatic,
cycloaliphatic or aromatic radical containing from 1 to 20 carbon
atoms.
Specific examples of useful polyfunctional initiators
include 1~3,5-trilithiopentane, 1,2,5-trilithlonaphthalene,
1,3,5~8~tetrallthiodecane, and 1,2,3,5-tetralithiocyclohexane.
The ~/B weight ratio in the above~described polymers will
generally be in the range of 5Q~5Q to 5~5 and preferably in the ~`
range of 40/60 to 15/85~ The block copolymers will generally
be in the range of w~ight average molecular weight from 10,000
to 750,000 and preferably from 50,000 to 350,000~
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In accordance with this invention, surface-dulling agents or
gloss-reducing agents are employed in the radial teleblock
copolymer-based compositions. Finely divided cellulosic materials,
finely divided textile fibers, finely divided hydrocarbon polymers, or
blowing agents can be employed as surface-dulling additives. These
additives can be incorporated into the polymeric compositions as
described in Serial Number 621,100 filed October 9, 1975;
U.S. 2,638,457; U.S. 3,268,636; and U.S. 3,77~,9~9 which disclose
methods suitable for incorporating various additives.
Suitable finely divided cellulosic materials include well
known materials such as cotton floc, linen fibers or wood flour.
Finely divided textile fibers useful in this invention
include, in addition to the above-mentioned cotton floc and linen
fibers, synthetic fibers, such as nylon, poly(ethylene terephthalate),
polyacrylonitrile, rayon, and the like. Textile fibers of length of
up to about 3 mm can be used.
Suitable hydrocarbon polymers that can be employed as
surface-dulling agents are those that possess a maximum melting point
of about 200C. Examples include high density polyethylene, low
density polyethylene, crystalline polypropylene and ethylenepropylene
copolymers, among others. Suitable size for the finely divided
polymers is in the range of about 5 microns to about 5 mm.
The amount of finely divide~ materials including the
cellulosic materials, textile fibers or hydrocarbon polymers employed
will generally be any amount which provides the desired degree of
surface-dulling. However, for practical application the amount of
such material added will usually fall within the range of about 2 to
about 75 parts by weight per 100 parts by weight rubber (phr).
Blowing agents, QS the term is herein employed, are
compounds which thermally decompose in the temperature range of about
120 to 230C, preferably 175 to 200C without causing loss of the
desirable properties of the radial teleblock copolymer with
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which they are being employed. These blowing agents can be
employed in quantities ranging from 0.05 to 1.0, preferably 0.05
to 0.5 phr. Examples of such compounds include 2,2'-azobis(2-
methylpropionitrile), N,N'-dinitrosopentamethyltetraamine, p,p'-
oxybis(benzenesulfonyl hydrazide), urea, azodicarbonamide and thelike. If the blowing agent is incorporated into the copolymer by
a mixing operation incolving an internal mixer or a 2-roll mill,
the blowing agent selected must be one possessing a decomposition
temperature above that of the mixing operation. The blowing agent
should also decompose at or below application temperature of the
rubber composition to the fabric. It is essential that the
blowing agent decompose during the application process or in a
subsequent heat treatment in order to provide the desired surface
roughness required for a reduction in gloss.
It is within the scope of this invention to include in
the radial teleblock copolymer-based composition any other additives
which are well known in the rubber art to provide desired pro-
perties. Such additives include the well known plasticizers,
extender oils, pigments, reinforcing agents, stabilizers, processing
aids, and, if desired, curing agents.
As the plasticizer component of the inventive footwear
upper materials any of the nonvolatile plasticizers which are well
known in the rubber art and which are compatible with the other
components of the composition can-be employed. Exemplary plasticizers
include dialkyl phthalates, rosin esters, mineral oils, as well
as the well known aromatic, naphthenic, or paraffinic extender oils.
The footwear upper materials of this invention can be
pigmented to any desired color using any appropriate pigmenting
material. Titanium dioxide and carbon black are well known pigments, -
though many other pigments are commercially available which cover
the entire spectrum of desired colors.
Fillers or reinforcing agents can be employed as desired
in the inventive compositions. Many materials which are well
known in the rubber art can be employed in these compositions. Such
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additives include the well known carbon black, clays, talc,
alkaline earth carbonates, silica, metallic oxides, and the like.
It is usually desirable to include stabilizers in the
inventive formulations. Such stabilizers include the well known
antioxidants and antiozonants, as well as ultraviolet and thermal
stabili~ers. Hindered phenols, substituted phosphites, phenolic
phosphites, dialkyl thiodipropionates, nickel dialkyldithio-
carbamates, and the like and mixtures thereof are examples of types
of stabilizers which are particularly beneficial in the present
invention.
If it is desired to include a release agent or processing
aid in the footwear upper composition, any of the well known waxes,
silicones, metal stearates, and the like can be employed to produce
the desired result.
Though the radial teleblock copolymer-based compositions
of this invention are moldable and remoldable, thus not requiring
vùlcanization, it can be desirable in some circumstances to include
curing agents in the formulation. If such is the case, the well ;
known sulfur or peroxide curing agents with the associated
accelerators and other additives, can be employed in the inventive
formulations.
The present invention contemplates a wide variety of
materials as the fibrous backing material upon which the radial -~
teleblock copolymer-based cQmposition is applied to give the
resultant footwear upper material. The fibrous organic material
can be in the form of woven or non-woven fabrics. Exemplary
materials include those cellulosic materials such as cotton or
rayon, synthetic textile materials such as polyamides, polyesters,
polyolefins, and the like as well as mixtures thereof.
The inventive radial teleblock copolymer-based compositions
can be prepared by any means well known in the art such as blending
the ingredients in an internal mixer and applying sufficient mixing
intensity to melt and subsequently homogeni~e the ingredients.
Care should be exercised in the initial mixing operation to insure
that any blowing agent present in the formulation is not decomposed
at the mixing temperature.
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The copolymer-based compo.sition is applied to the ~acking
material employing anyof the means which are well known in the art.
It is generally desirable to heat the composition to a temperature
above the softening point and to apply it as a layer to the fibrous
backing material. The temperature of the application process can
be sufficiently high to decompose the blowing agent or it can be
below the blowing agent decomposition temperature in which case a
subsequent heat treating step in which the temperature is raised to
the point at or above the decomposition temperature of the blowing
agent is applied for a period of time sufficient to provide the
desired degree of surface-dulling.
It is also within the scope of this invention to bond the
copolymer-based composition to the backing material by means of a
suitable adhesive or cement, such as a polyurethane-based cement,
an ethylene/vinyl acetate copolymer-based cement or a styrene/buta-
diene copolymer-based cement. Heat-treatment of a blowing agent-
containing composition can be applied before or after bonding to
the fabric backing.
The copolymer-based composition is generally applied to
the organic backing material in a coating generally from 0.1 mm to
5 mm thick, though it is generally preferred to apply a coating
from 0.5 to 3 mm thick.
The various components of the copolymer-based composition
are generally employed, when used, in the broad and preferred
ranges given in parts by weight in the following summary table:
Ingredient BroadPreferred :~
Copolymer 100 100
Plasticizer 20-150 50-100
Blowing Agent -10 2-6
Dulling Agent a-8o 20-70
Filler a-150 -50
Pigment a_10 1-7
Stabilizer a-5 0.5-2
Processing Aid a-5 0.5-2
Curatives a 5 a 2
a) Finite amount, proyiding that either a blowing agent
or dulling agent is present.
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Example
The following illustrates the preparation of a film of a
composition suitable for use in footwear upper material based upon
a butadiene/styrene radial teleblock copolymer.
The ingredients of the copolymer-based composition were
combined in proportions given in the following recipe.
RECIPE
Ingredient Parts by Weight
Copolymer/Extender Oil 150
Oil 25
Wood Flour 60
Titanium dioxide 3
StabilizerC 0.5
Dilauryl thiodipropionate 0.5
Stearic Acid
Azodicarbonamide S
Yellow Pigment 2 `
Red Pigment 0.3
Carbon Black 0.1
0 a) 60/40 Butadiene/styrene radial teleblock copolymer coupled
using silicon tetrachloride - m.w. (weight average) of 273,000,
extended with 50 phr naphthenic oil.
b) Naphthenic oil.
c) Hindered phenol - Irganox 1035 from Ciba-Geigy.
The above ingredients were combined and blended in an
internal mixer by heating with mixing to a temperature above the
melting point of the poly~er.
A portion of the resultant copolymer-based composition
was compression molded at 143C for two minutes. In Table I are
recorded some phy6ical propertie~ of the thus-molded comp~itioD.
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Table I
Property Value
300% modulus, psi 350
Tensile Strength, psi 470
Elongation, ~ 680
Shore A Hardness 65
Melt Index 2
In Table II are recorded data on air permeability or
breathability of the above composit:ion in films of varying thickness.
A control run employing a film of polytvinylchloride) was provided
for a comparison of breathability of the inventive composition with
a prior art footwear upper material.
Table II
Run No. Thickness, mmAir Permeabilitya
1 0.64 1311
2 0.76 1154
3 1.14 1227
4 (PVC) 0.84 224
a) ASTM D1434-75
The data in Table II show approximately a 5-fold improve-
ment in air permeability for the inventive footwear upper formulation
compared to the prior art, poly(vinylchloride) compositions. The
inventive film also exhibited a desirable suede-like surface. The
thermoplastic nature of the inventive elastomer-based compositions
(moldability and green strength without vulconization) and the
above-demonstrated air permeability and suede-like surface are
desirable characteristics for materials suitable for use in
footwear uppers.
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