U.S. patent application number 10/520513 was filed with the patent office on 2005-11-17 for waterproof and breathable sole for shoes.
This patent application is currently assigned to Geox S.p.A.. Invention is credited to Ferrarese, Antonio, Moretti, Mario Polegato.
Application Number | 20050252035 10/520513 |
Document ID | / |
Family ID | 30012880 |
Filed Date | 2005-11-17 |
United States Patent
Application |
20050252035 |
Kind Code |
A1 |
Moretti, Mario Polegato ; et
al. |
November 17, 2005 |
Waterproof and breathable sole for shoes
Abstract
A waterproof and breathable sole for shoes, having a structure
that includes a mid-sole component with a membrane made of a
material that is impermeable to water and permeable to water vapor
and connected in spots with a lower protective layer made of a
material that is resistant to hydrolysis, water-repellent,
breathable, and/or perforated. A tread made of perforated elastomer
is joined perimetrically and hermetically to the component. The
membrane is associated with the protective layer by a
thermoreactive adhesive.
Inventors: |
Moretti, Mario Polegato;
(Crocetta Del Montello, IT) ; Ferrarese, Antonio;
(Isola Della Scala, IT) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
Geox S.p.A.
Via Feltrina Centro, 16
Montebelluna, Localita Biadene, Treviso
IT
31044
|
Family ID: |
30012880 |
Appl. No.: |
10/520513 |
Filed: |
January 7, 2005 |
PCT Filed: |
July 7, 2003 |
PCT NO: |
PCT/EP03/07273 |
Current U.S.
Class: |
36/3B |
Current CPC
Class: |
A43B 7/125 20130101;
B29D 35/142 20130101; B29D 35/122 20130101 |
Class at
Publication: |
036/003.00B |
International
Class: |
A43B 013/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 9, 2002 |
IT |
PD2002A000187 |
Claims
1-7. (canceled)
8. A waterproof and breathable sole for shoes, comprising: a
mid-sole component comprising: a membrane made of a material that
is impermeable to water and permeable to water vapor; a lower
protective layer made of a material that is resistant to
hydrolysis, water-repellent, breathable, and/or perforated; said
membrane being connected in spots with said lower protective layer;
and a tread made of perforated elastomer that is joined
perimetrically and hermetically to the component; and wherein said
membrane is associated with said protective layer by a
thermoreactive adhesive.
9. The sole of claim 8, wherein said membrane and said protective
layer associated therewith are joined hermetically to said tread,
which is provided by overmolding or in place assembling on said
component.
10. The sole of claim 8, wherein said membrane and said protective
layer are part of a mid-sole with a preassembled insert that
comprises a perimetric element that is overmolded or assembled in
place and surrounds said membrane and said protective layer and is
joined to them hermetically, said insert being coupled to said
tread, which is overmolded or assembled in place thereon.
11. The sole of claim 8, wherein said thermoreactive adhesive is a
thermoplastic polyurethane adhesive.
12. A method for joining a membrane made of a material that is
impermeable to water and permeable to water vapor to a protective
layer made of a material that is resistant to hydrolysis,
water-repellent, breathable and/or perforated, to provide
waterproof and breathable soles for shoes, the method comprising:
applying in spots thermoreactive adhesives between said membrane
and said protective layer.
13. The method of claim 12, wherein said thermoreactive adhesive is
a thermoplastic polyurethane adhesive.
14. A method for making a waterproof and breathable sole for shoes
that has a structure including a mid-sole component with a membrane
made of a material that is impermeable to water and permeable to
water vapor and is connected in spots with a lower protective layer
made of a material that is resistant to hydrolysis,
water-repellent, breathable and/or perforated; and a tread made of
perforated elastomer that is joined perimetrically and hermetically
to the component; the method comprising: connecting said membrane
to said protective layer by a thermoreactive adhesive.
Description
TECHNICAL FIELD
[0001] The present invention relates to an improved waterproof and
breathable sole for shoes.
BACKGROUND ART
[0002] Plastic waterproof and breathable soles for shoes are
already known.
[0003] One of these soles is disclosed in Italian patent no.
1,282,196 by the same Applicant.
[0004] In this case, the sole comprises:
[0005] a mid-sole with a membrane made of a material that is
impermeable to water and permeable to water vapor, associated with
a lower protective layer made of a material that is resistant to
hydrolysis, water-repellent, breathable and/or perforated;
[0006] a tread made of perforated elastomer that is joined
perimetrically and hermetically to the mid-sole.
[0007] A waterproof and breathable sole disclosed in WO 98/51177 by
the same Applicant is also known; it comprises a preassembled
insert in which there is a membrane that is impermeable to water
and permeable to water vapor, associated with a lower protective
layer made of a material that is resistant to hydrolysis,
water-repellent, breathable and/or perforated.
[0008] The insert is completed by an element that is overmolded or
assembled in place and surrounds the membrane and the protective
layer and is joined hermetically to them.
[0009] The insert is part of a mid-sole and is joined together with
said mid-sole to a tread made of perforated plastic, which is
overmolded or assembled in place.
[0010] In both cases, the protective layer arranged below the
membrane is meant to protect said membrane against piercing due to
foreign objects accidentally passing through the holes.
[0011] The protective layer is normally made of felt and is coupled
to the membrane in a breathable manner (by means of spots of
thermoplastic adhesive which has for example a polyurethane base),
to allow the passage of the vapor from the inside of the shoe
toward the outside through the holes provided in the tread.
[0012] Although the soles described above have been commercially
available for years now and are unanimously acknowledged to be
capable of ensuring a correct exchange of heat and water vapor
between the microclimate inside the shoe and the external
microclimate, they have been found to have drawbacks, including in
particular the tendency for the membrane to tear due to the
different traction elasticity modulus with respect to the tread,
with which it is monolithically assembled peripherally.
[0013] The membrane is in fact normally made of expanded
polytetrafluoroethylene, which is a scarcely elastic material,
while the tread by its very nature and due to its operating
requirements must be very elastic and flexible.
[0014] Accordingly, the membrane is unable to absorb the flexural
stresses that produce an elastic elongation of the polymer, of
which the elastomeric tread is made (PVC, TR, polyurethane, rubber,
et cetera), in movements, during use and accordingly tends to tear
because its elasticity modulus is exceeded, and loses its
waterproofness.
[0015] The protective element below the membrane, which is normally
made of polyester felt, has been found unable, on its own, to
absorb the tensions induced by the deformations of the sole.
[0016] In order to reduce the elongation, the structure disclosed
in WO 02/32246 A1 has been adopted; this patent describes the use
of composite materials with a high ultimate tensile strain and low
elongation, but the insertion of said materials is expensive and
also causes a general stiffening of the shoe.
[0017] Furthermore, the problem of the breakage of the membrane is
not solved permanently, because of the reversibility of the
phenomenon of thermoplasticity of the polyurethane adhesive used to
laminate the membrane with the felt layer: the melting point of
said adhesive (for example 65.degree. C.) is in fact lower than the
temperature (for example 180.degree. C.) at which the polymer that
constitutes the tread and must form a peripheral seal on the
membrane is injected into the mold.
[0018] Temperatures higher than the melting point of the
polyurethane adhesive can be reached both during the normal
production of the shoe and during use of the shoe (for example when
walking on hot tarmac during the summer period).
[0019] By reaching temperatures higher than the melting point, the
thermoplastic adhesive is reactivated and the viscosity is reduced
considerably (it is known that viscosity is a function of
temperature), allowing complete absorption of said adhesive by the
felt.
[0020] This means that once the assembly cools, there is no longer
enough adhesive to allow adequate coupling of the membrane to the
felt layer.
[0021] All the stress to which the sole is subjected during use is
therefore transmitted to the membrane, which tears due to the
problems described above.
[0022] This problem is entirely new in soles with respect to other
uses for which a membrane that is impermeable to water and
permeable to vapor is used.
[0023] This performance at high temperatures is in fact not
required, for example, for producing laminated fabrics to be used
as a lining on an upper, because in such cases temperatures on the
order of the temperatures reached in the molding of soles made of
polymeric materials are never reached.
[0024] In these cases, a maximum temperature of 100.degree. C. can
in fact be reached.
DISCLOSURE OF THE INVENTION
[0025] The aim of the present invention is therefore to provide a
waterproof and breathable sole for shoes having an improved
structure that is capable of eliminating the drawbacks noted above
in known types, which lead to the tearing of the waterproof and
water vapor-permeable membrane.
[0026] Within this aim, an object of the invention is to not reduce
in any case the waterproofness and breathability capabilities of
the sole.
[0027] Another object is to provide a sole that does not entail
particular constructive complications with respect to known
soles.
[0028] Another object is to provide a sole whose costs are
competitive with respect to the costs of known types.
[0029] This aim and these and other objects that will become better
apparent hereinafter are achieved by a waterproof and breathable
sole for shoes, having a structure that comprises:
[0030] a mid-sole with a membrane made of a material that is
impermeable to water and permeable to water vapor and is associated
in spots with a lower protective layer made of a material that is
resistant to hydrolysis, water-repellent, breathable and/or
perforated;
[0031] a tread made of perforated elastomer that is joined
perimetrically and hermetically to the mid-sole;
[0032] said structure being characterized in that said membrane is
associated with said protective layer by means of a thermoreactive
adhesive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Further characteristics and advantages of the invention will
become better apparent from the detailed description of some
embodiments thereof, illustrated by way of non-limitative example
in the accompanying drawings, wherein:
[0034] FIG. 1 is a transverse sectional view of a waterproof and
breathable sole for shoes having the structure according to the
invention, in a first embodiment thereof;
[0035] FIG. 2 is a transverse sectional view of a waterproof and
breathable sole for shoes having the structure according to the
invention, in a second embodiment thereof.
WAYS TO CARRYING OUT THE INVENTION
[0036] With reference to FIG. 1, a waterproof and breathable sole
for shoes has, in a first embodiment, a structure that comprises a
mid-sole 10 that is composed of a membrane 11 made of a material
that is impermeable to water and permeable to water vapor (normally
commercially available and made for example of expanded
polytetrafluoroethylene), laminated over a supporting mesh 12 made
of synthetic material and associated, by way of spots of adhesive
13, with a lower protective layer 14 made of a material that is
resistant to hydrolysis, water-repellent, breathable and/or
perforated, preferably a polyester felt.
[0037] The structure further comprises a tread 15 made of
elastomer, with through holes 16, which is overmolded or assembled
in place on the mid-sole 10 and is perimetrically joined
hermetically thereto (see the borders 17 that surround its edges in
FIG. 1).
[0038] According to the invention, the structure is characterized
in that said membrane 11 is associated with said protective layer
14 by way of a thermoreactive adhesive.
[0039] Thermoreactive adhesives are adhesives that are per se known
in another technical field; they are in fact used for example to
produce barrier fabrics for surgical uses, which are formed by two
or more layers of different materials that are laminated
together.
[0040] Said fabrics in fact require repeated sterilizations in an
autoclave at high temperatures in order to allow their reuse, and
it is evident that the high temperature reached during the
sterilization operation must not cause the separation of the two or
more elements that constitute the barrier fabric.
[0041] These adhesives, due to the temperature, produce many
intermolecular bonds (between molecules), thus forming a
three-dimensional structure that is partially rigid and in any case
thermally irreversible.
[0042] The bonds occur between the NCO and OH groups that are
present in the molecular chains that constitute said adhesives.
[0043] Thermoreactive adhesives, usable for the purposes of the
invention are, for example, thermoplastic polyurethane adhesives
which are manufactured by the company SCHAETTI AG, Switzerland, and
marketed under the name PU SCHAETTI FIX 6050.
[0044] Practical tests of the use of these thermoreactive adhesives
to associate in spots the membrane 11 with the protective layer 14
have shown that their molecular bonds do not allow melting and
absorption at high temperatures of the adhesive by the felt of the
protective layer 14, preventing the separation of the membrane 11
and thus allowing the distribution of the stress over a larger
cross-section (membrane 11+felt of the layer 14).
[0045] All this avoids the breakage of the membrane 11 due to its
elasticity modulus being exceeded.
[0046] With reference now to FIG. 2, a waterproof and breathable
sole for shoes, in a second embodiment, has a structure that
comprises a preassembled insert 110, which corresponds to the
mid-sole 10 of the previous embodiment and in which there is a
membrane 111 which is made of a material that is impermeable to
water and permeable to water vapor (normally commercially
available, for example made of expanded polytetrafluoroethylene),
which is laminated over a supporting mesh 112 made of synthetic
material and associated by spots of adhesive 113 with a lower
protective layer 114 made of a material that is resistant to
hydrolysis, water-repellent, breathable and/or perforated,
preferably a polyester felt.
[0047] The insert 110 is completed by a perimetric element 117 that
is overmolded or assembled in place and surrounds the membrane 111
(with the mesh 112) and the protective layer 114 and is joined
hermetically to them.
[0048] The insert 110 is joined to a tread 115 made of elastomer,
with through holes 116, that is overmolded or assembled in place
thereon.
[0049] In this case also, the structure is characterized in that
said membrane 111 is associated with said protective layer 114 by
way of a thermoreactive adhesive 113.
[0050] The method for obtaining the described improved shoe sole is
based on the steps for assemblying the sole parts as disclosed in
relation with the preferred embodiments of the invention.
[0051] In practice it has been found that the intended aim and
objects of the present invention have been achieved.
[0052] A waterproof and breathable sole for shoes having an
improved structure has in fact been devised which eliminates the
drawbacks suffered by known types which lead to the tearing of the
waterproof and vapor-permeable membrane, without reducing the
waterproofness and breathability characteristics of the sole.
[0053] Moreover, the manufacture of the sole does not entail
particular constructive complications with respect to conventional
soles.
[0054] The invention thus conceived is susceptible of numerous
modifications and variations, all of which are within the scope of
the appended claims.
[0055] All the details may further be replaced with other
technically equivalent elements.
[0056] In practice, the dimensions may be any according to
requirements.
[0057] The disclosures in Italian Patent Application No.
PD2002A000187 from which this application claims priority are
incorporated herein by reference.
* * * * *