ITPD20100286A1 - BREATHABLE FOOTWEAR WITH WATERPROOF AND BREATHABLE SOLE - Google Patents

Description

BREATHABLE FOOTWEAR WITH WATERPROOF AND BREATHABLE SOLE

DESCRIPTION

The present invention relates to a breathable shoe with a waterproof and breathable sole. As is known, the part of the foot that has the greatest sweating effect is that of the sole.

Therefore, the area of the shoe where moisture from sweating can accumulate most is the interface between the sole of the foot and the sole. Here, the developed sweat saturates the air with moisture and mostly condenses by stagnating on the footbed.

Only a marginal portion of the humidity produced by perspiration spreads to the sides of the upper, and from these it comes out if they are transpiring.

This effect of sweat stagnation in the plantar area is particularly accentuated in footwear with rubber soles; in fact, in these cases the transpiration through the sole is prevented by its total impermeability.

As is well known, the stagnation of sweat in the plantar area generates a feeling of discomfort in the user of the shoe, as well as being a preferential site for the development of bacterial cultures, notoriously at the origin of bad smells.

It is therefore a commonly felt need to remedy the stagnation of humidity from perspiration in correspondence with the plantar area of the footwear.

A first attempt to satisfy this need consists in the solution proposed in the Italian patent n ° 1232798.

The teaching contained in this patent document consists in dividing the rubber sole into two layers, of which the lower one has through micro-holes, and in interposing a semipermeable membrane perimetrically joined to the two layers, to avoid infiltration of water and thus obtaining a sole impermeable to water in the liquid state and permeable to water vapor. For simplicity, below an element with the property of being impermeable to water in the liquid state and permeable to water vapor is indicated as waterproof and breathable.

The semipermeable membranes that the inventor of the Italian patent n ° 1232798 teaches to use, are for example of the type described in patents US4,187,390 and US4,194,041 in the name of W.L.Gore or US6,228,477 in the name of BHA Technologies.

These are made with thin films in expanded polytetrafluoroethylene, in short e-PTFE, with thicknesses that generally vary from 19 to 70 microns, waterproof and breathable.

Their microstructure is characterized by the presence of dense areas, called nodes, interconnected by elongated threads, called fibrils.

These semipermeable membranes, initially created for the military sector, have been developed and used in the clothing and footwear sector, to avoid the accumulation of steam from perspiration in the garments and provide footwear with uppers with waterproof and breathable linings.

Since the market in the clothing and footwear sectors has always required soft and comfortable garments, in the applications described there is a strong need to ensure that the membrane, intended as a functional layer, does not compromise these characteristics.

This need was expressed in a real technical prejudice that involved the use of membranes made in thin thicknesses to be laminated with support materials and / or aesthetic finishing, such as fabric or leather, so as to to obtain finished laminates that have accentuated characteristics of flexibility, ease of folding, softness, surface slipperiness, compressibility and extensibility and low weight per unit of surface.

On the other hand, the films that make up these membranes show poor mechanical resistance characteristics, precisely because of their thin thickness.

In fact, it should be noted that the resistance value of the laminate derives mainly from the characteristics of the fabric or support layer to which the membrane is coupled.

In particular, the films in polymeric material available, which are used to make such membranes as mentioned, have thicknesses generally from 19 to 70 microns, which give them poor resistance to penetration, i.e. less than 5 N.

Penetration resistance means the characteristic defined by measurement performed according to the methodology set out in the ISO 20344-2004 standard, in chapter 5.8.2 "Determination of the penetration resistance of the sole", relating to safety footwear.

This poor mechanical resistance to penetration led the inventor of the aforementioned Italian patent No. 1232798 to prevent contact of the membrane with foreign bodies, by limiting the diameter of the holes in the sole to which the membrane faces.

This solution, however, has proved to limit the area of the sole used for transpiration and furthermore the holes can become obstructed.

The teaching contained in the European patent n ° 858.270, in the name of the same applicant, proposes a solution aimed at overcoming these drawbacks, but still not entirely devoid of perfectibility.

This patent document illustrates a shoe with a perforated elastomer sole and comprising a midsole comprising a waterproof and breathable membrane superimposed on a lower protective layer, preferably in felt, treated to be water-repellent.

Since the protective layer is not made of waterproof material, it is not possible to directly seal the midsole with the sole, but a waterproof perimeter element is used that creates a sealing bridge between the waterproof and breathable membrane and the sole . As said, this invention, while allowing effective protection of the membrane from the penetration of external bodies, has some perfectibility.

In particular, the protective element gradually loses its water-repellent characteristics and therefore tends to become soaked in water and / or mud or other types of dirt, absorbed through the holes in the tread, compromising the breathability of the sole and also creating a favorable environment for the proliferation of microorganisms, such as mold and bacteria, which can cause the shoe to smell bad.

Another drawback consists in the fact that, in use, the cyclic flexion and traction to which the midsole is subjected during walking tends to cause progressive wear and tear of the membrane, thus causing loss of impermeability to the sole.

A further solution is proposed in US patent no. US6508015 in the name of Rauch Max, in which a sole structure with two superimposed layers is proposed, of which the upper, intended to be turned towards the upper part of the shoe, is elastic and permeable to water vapor.

The lower layer, which covers less than 70% of the upper layer, acts as a support and creates the tread.

The upper layer is made for example of sintered plastic material or with non-woven fabrics so as to present a microporous structure which is not waterproof.

A drawback of this solution consists in the fact that during the use of the shoe, the microporous upper layer, left largely exposed by the lower layer, tends to soak up water when it comes into contact with it, absorbing it, retaining it and partly releasing it over time, soiling trampled surfaces.

Furthermore, the upper layer tends to degrade in contact with the absorbed water.

In order to obtain the impermeability of the sole, in this patent text the teaching is presented to treat the upper layer in order to make it water-repellent or to cover it with a waterproof and breathable membrane, placed above it.

However, the hydrophobic treatment is of poor durability, causing the sole to lose its impermeability, while the application of a breathable and waterproof membrane above the upper layer actually reproduces a structure similar to the one already described presented the membrane supported by one or more protective layers, thus proposing the same drawbacks and limits in quantitative terms of breathability.

The object of the present invention is to provide a breathable shoe with a waterproof and breathable sole, which allows to overcome the limits presented by known footwear and soles, in particular by allowing to prevent the retention and release of water with which in use came into contact, presenting at the same time an efficient and durable breathability and impermeability.

Within this aim, an object of the invention is to propose a breathable shoe with a waterproof and breathable sole which, compared to the products known today, has a greater resistance to damage by foreign bodies which, during its use, they tend to penetrate the sole, such as small stones, particularly if sharp, or the like.

Another object of the invention is to provide a breathable shoe with a waterproof and breathable sole which is more durable waterproof and breathable than known products.

This task, as well as these and other purposes which will appear better later, are achieved by a breathable shoe with a waterproof and breathable sole, comprising

- an assembly of the upper,

- a sole, joined to said upper assembly and comprising a body made of waterproof material having a tread and having at least one region permeable to water vapor,

- at least one waterproof and breathable membrane covering said at least one region, towards the inside of said shoe,

- at least one protective element covering, at least partially, a lower face of said at least one membrane,

said shoe being characterized in that it further comprises at least one waterproof and breathable protective screen covering said at least one region and substantially interposed between this and said at least one protective element, said protective screen being sealed impermeable to said body in correspondence with at least one area of said peripheral body to said at least one region.

Further characteristics and advantages of the invention will become clearer from the description of preferred but not exclusive embodiments of the waterproof and breathable sole according to the invention, illustrated, by way of non-limiting example, in the accompanying drawings, in which:

Figure 1 shows a transpiring shoe according to the invention, in a first embodiment, in cross section;

Figure 2 shows a transpiring shoe according to the invention, in a second embodiment, in cross section;

Figure 3 shows a transpiring shoe according to the invention, in a variant of said second embodiment, in cross section;

Figure 4 shows a transpiring shoe according to the invention, in a third embodiment, in cross section.

With reference to the aforementioned figures, the numeral 10 generally indicates a breathable shoe with a waterproof and breathable sole, in a first embodiment, comprising

- an assembly of the upper 11,

- a sole 12, joined to the upper assembly 11 and comprising a body 13 made of waterproof material having a tread 14 and presenting a region 15 permeable to water vapor,

- a waterproof and breathable membrane 16 covering the region 15, towards the inside of the shoe 10,

- a protective element 17 covering a lower face 16a of the membrane 16.

According to the invention, the shoe 10 has a particular peculiarity in the fact that it further comprises a waterproof and breathable protective screen 18 covering the region 15 and substantially interposed between this and the protective element 17, the protective screen 18 being sealed waterproof to the body. 13 in correspondence with the region 13a of the body 13 peripheral to the region 15, preferably as described below.

The tread 14 is conveniently the lower surface of the body 13, which in use comes into contact with the ground, but, in an equivalent way in alternative embodiments of the invention, it can be an element distinct from said body 13, associated with it at the bottom.

Conveniently, the region 15 is defined by a plurality of holes 15a passing through the body 13.

In alternative embodiments of the invention, in a substantially equivalent way, said region can be defined by at least a wide opening, in which structural reinforcing and supporting elements for said protective screen can possibly be provided, for example to form a lattice.

According to the contingent requirements, in alternative embodiments of a breathable shoe according to the invention, this comprises a sole which generally has at least one region permeable to water vapor covered by at least one waterproof and breathable membrane, under which at least one a protective element, at least one of said protective screen being further provided in correspondence with said at least one region.

Advantageously, the protective screen 18 is microporous and has pores with an average opening of less than 1 µm, preferably such pores have an average opening of less than 0.5 µm, and in particular suitably at least 50% of said pores have an opening average less than 0.5 µm.

The protective screen 18 advantageously consists of a sheet of material obtained from a substantially homogeneous mixture consisting of - a high molecular weight polyolefin, in a percentage concentration of the volume of said mixture between 8% and 98%,

- a filler able to promote the formation of micropores, in a percentage concentration of the volume of said mixture between 1% and 92%, - a plasticizer, in a percentage concentration of the volume of said mixture between 1% and 40%.

Where said polyolefin is preferably a UHMW polyethylene, acronym for the English word Ultra High Molecular Weight, and conveniently said filler is chosen between silicic anhydride and silicic acid, the plasticizer being an oil insoluble in water, preferably petroleum oil.

Alternatively, the protective screen 18 is conveniently made of a material chosen from expanded polytetrafluoroethylene, in the code ePTFE, polyurethane, in the code PU, polyester, in the code PES, polypropylene, in the code PP, polyethylene, in the code PE, and the like.

Preferably, the protective screen 18 has a structure chosen from among

- a structure consisting of a single integral layer, preferably extruded, with a thickness substantially comprised between 0.1 mm and 5 mm,

- a structure consisting of a plurality of layers joined by lamination to form a multilayer element with a thickness substantially between 0.1 mm and 5 mm,

- a structure consisting of a plurality of laminated layers, a permeable material cohesive with them being provided between them.

The protective element 17 is conveniently made of a material resistant to hydrolysis and transpiring, chosen from felt, non-woven fabric and the like, treated in such a way as to be water-repellent, and conveniently with a thickness substantially between 0.5 mm and 5 mm.

The membrane 16 is conveniently of the type of the breathable and waterproof membranes commonly available on the market, for example in expanded polytetrafluoroethylene, also known as e-PTFE, polyurethane, also known as PU, or similar, and it is conveniently associated with at least one jersey that reinforces it.

Furthermore, a sealing element 19 of the periphery 16b of the membrane 16 to the body 13 is advantageously provided, which conveniently bridges the side-by-side edges, sealing them reciprocally.

By way of non-limiting example, Figure 1 represents the portion in which the sealing element 19 makes the waterproof seal of the periphery 16b of the membrane 16 to the body 13 by a segment of a line-point line indicated by the reference A. .

The sealing element 19 is advantageously made of waterproof polymeric material, and is adhered as a seal to the periphery 16b of the membrane 16 and to the body 13 with a layer of glue resistant to hydrolysis and capable of ensuring a ̃Effective sealing, preferably polyurethane type.

The waterproof polymeric material with which the sealing element 19 is made is suitably polyvinyl chloride, PVC, or thermoplastic polyurethane, TPU, or the like.

In alternative and substantially equivalent embodiments, the sealing element is advantageously a thermoplastic hot-melt adhesive film, in polyurethane or polyester, in polyamide or in polyolefin, which can be activated by heat and pressure.

A film particularly suitable for the realization of said sealing element is proposed on the market by the company Bemis Associates Inc with the product code 3218, or by the company Collano AG, XIRO Adhesive Films with the product code XAF 36.004 (Pure).

Still, in a further and alternative way of implementing the seal element in a substantially equivalent way, it is made of the material constituting the body of the sole, joined with an impermeable seal at the periphery of the membrane.

Advantageously, the protective screen 18 and the body 13 are connected with a waterproof seal, suitably in correspondence with the region 13a peripheral to the region 15.

Said waterproof seal connection is preferably made by gluing or by high frequency welding.

Alternatively, according to the contingent requirements for implementing the invention, said seal connection is conveniently made by gripping the protective screen 18 of the construction material of the body 13 injected into the mold during the forming phase.

In particular, in this case, said seal connection is obtained by co-molding on the protective screen 18 of the material that forms the body 13, or of a component thereof such as, for example, in the case in which it is formed by a portion bottom and a midsole.

In this way, in fact, the forming material of the body 13, or of its component, clings as an impermeable seal to the protective screen 18, suitably in correspondence with the area 13a of the body 13, peripheral to the region 15 permeable to water vapor.

In the attached figures, by way of non-limiting example, said seal connection is indicated by a dotted line segment marked with the reference B.

Advantageously, the upper assembly 11, the outline of which is schematized in broken line in Figures 1, 2 and 3, according to the requirements of implementation of the invention, comprises at least

- a breathable, external upper,

- a breathable, internal, ed

- a breathable insole to which the lower flaps of the upper and of the lining are joined in a per se known manner, for example according to a mounted construction or by stitching, for example of the Strobel type.

In figures 1, 2 and 3, the upper assembly 11 is schematized in a broken line and the upper, the lining and the insole are not shown, as they are known elements per se, the structure of which is advantageously chosen among those known in a manner consistent with the contingent requirements of execution of the invention.

Preferably, a spacer element 20 is provided which covers the upper face 16c of the membrane 16.

Said spacer element 20 has the main task of protecting the membrane 16 from the possible abrasive action of the insole, being interposed between them.

Conveniently, the spacer element 20 is made of transpiring or perforated material, for example of felt, or of fabric, or of polymeric material or of cellulosic material.

In a second embodiment of a shoe according to the invention, illustrated by way of non-limiting example in Figure 2, where the reference 100 is indicated and the elements corresponding to those described up to now are also indicated with the same references , the body 13 advantageously comprises a lower part 21 and an upper part 22, the protective screen 18 being sealed to the lower part 21 which has the region 13a peripheral to the region 15.

Conveniently, the upper part 22 is joined with a waterproof seal to the periphery 16b of the membrane 16.

Said waterproof seal union, identified by way of non-limiting example in Figures 2 and 3 by a segment of a line-point line indicated with the reference C, is preferably implemented by gluing or, alternatively, according to the contingent requirements of implementation of the invention, is conveniently carried out by clinging to the periphery 16b of the membrane 16 of the material for making the upper part 22 injected into the mold during the formation of the sole 13.

In particular, in this case, said seal connection is obtained by co-molding on the periphery 16b of the material that forms the upper part 22.

In particular, the sole 100 preferably comprises a spacer element 20 permeable to water vapor and superimposed on the membrane 16 to cover it to protect it from any abrasive action that the insole could exert on it during the use of the shoe 10.

Advantageously, the spacer element 20 is made of transpiring or perforated material, for example of felt or fabric or plastic material or cellulosic material.

If the upper part 22 is made by co-molding, advantageously the spacer element 20 also acts as a barrier to the passage, towards the membrane 16, of the material used to make the upper part 22 during injection into the mold.

In an alternative executive variant, not shown in the attached figures, said spacer element is replaced by a central portion of said upper part, having through holes or openings so as to be permeable to water vapor, to define part of said region, of said sole body, permeable to water vapor.

In said alternative variant, the lower part of the sole body is entirely covered by the upper part of the sole body.

With particular reference to Figure 3, in a variant of said second embodiment, in a shoe according to the invention, indicated with reference 100a, the protective screen 18 advantageously has a perimeter band 18a uncovered, from the protective element 17 and from the membrane 16 which it covers below.

In correspondence with said perimeter band 18a the protective screen 18 is associated with a waterproof seal to the upper part 22 of the body 13 of the sole 12.

Said waterproof seal association, illustrated by way of a non-limiting example by means of a dotted segment indicated by the reference D in figure 3, is conveniently implemented by gluing or, in the case of formation by co-molding of the upper part 22, for clinging to the perimeter band 18a of the material for making the upper part 22, injected into the mold.

In a third embodiment of a breathable shoe with waterproof and breathable sole according to the invention, illustrated by way of non-limiting example in Figure 4 where it is globally indicated with the reference 200 and where the elements corresponding to those described up to now, the upper assembly 11, suitably comprising a breathable, external upper 23, and a breathable lining 24, and a breathable insole 25.

In general, according to the contingent requirements, the upper assembly conveniently comprises at least a breathable upper, a lining and an insole.

Advantageously, the membrane 16 constitutes a lower layer of the insole 25, or, in a substantially equivalent way, is suitably associated with a layer of the insole 25.

The lower flaps of the upper 23 and of the lining 24 are conveniently joined to the insole 25, preferably by means of seams.

In this case, the periphery 16b of the membrane 16 and the body 13 of the sole 12 are conveniently connected with a waterproof seal by means of the construction material of the body 13, or of one of its components, which clings in a waterproof seal to the periphery 16b when the body 13 is formed by co-molding on the upper assembly 11.

Alternatively, the periphery 16b of the membrane 16 and the body 13 of the sole 12 are connected with a waterproof seal, suitably by gluing the membrane 16 to the body 13 of the sole 12, or to one of its components such as a midsole.

Furthermore, the protective screen 18 and the body 13 are advantageously connected with a waterproof seal in correspondence with the zone 13a, peripheral to the region 15 permeable to water vapor.

The seal connection between the membrane 16 and the body 13 of the sole 12 is illustrated by way of non-limiting example in figure 4 with a dash-dot line segment indicated with the reference E.

Thus, the seal connection between the protective screen 18 and the body 13 of the sole is illustrated by way of non-limiting example in Figure 4 with a dash-dot line segment indicated with the reference B, in analogy to what described here.

Advantageously, the waterproof seal connection of the body 13 with the protective screen 18 is carried out by gluing or co-molding the material constituting the body 13, as already described with regard to the seal connection of the body 13 with the membrane 16.

In practice it has been found that the invention achieves the intended aim and objects by producing a breathable shoe with a waterproof and breathable sole which allows the limits presented by known footwear and soles to be overcome, in particular by making it possible to prevent retention and release. of water with which the sole in use comes into contact, thanks to the presence of the protective screen which, being impermeable to water and sealed to the body of the sole, prevents water from reaching the protective element of the membrane, while still being breathable.

Furthermore, a breathable shoe with a waterproof and breathable sole according to the invention, compared to known products, has a greater resistance to damage that can be induced by foreign bodies which, during its use, tend to penetrate the sole such as small stones , particularly if sharp, or similar, in fact even in case of penetration of the protective screen, the membrane, protected by the protective element, preserves the waterproofness and breathability of the sole.

A shoe with a waterproof and breathable sole according to the invention also has a more durable waterproofness and breathability than known products, thanks to the collaboration of the membrane and the protective screen which cooperate in preserving the waterproofness of the sole and are also breathable.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept; moreover, all the details can be replaced by other technically equivalent elements.

In practice, the materials employed, so long as compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art.

Where the features and techniques mentioned in any claim are followed by reference marks, such marks have been affixed for the sole purpose of increasing the intelligibility of the claims and consequently such reference marks have no limiting effect on the interpretation of each element. identified by way of example by these reference signs.

Claims (15)

CLAIMS 1) Breathable footwear (10, 100, 100a, 200) with waterproof and breathable sole, comprising - an assembly of the upper (11), - a sole (12), joined to said upper assembly (11) and comprising a body (13) made of waterproof material having a tread (14) and having at least one region (15) permeable to water vapor, - at least one waterproof and breathable membrane (16) covering said at least one region (15), towards the inside of said shoe (10, 100, 100a, 200), - at least one protective element (17) covering, at least partially, the lower face (16a) of said at least one membrane (16), being said shoe (10, 100, 100a, 200) characterized in that it further comprises at least one waterproof and breathable protective screen (18) covering said at least one region (15) and substantially interposed between this and said at least one protective element (17) , said protective screen (18) being sealed impermeable to said body (13) in correspondence with at least one area (13a) of said body (13) peripheral to said at least one region (15). 2) Footwear, according to claim 1, characterized in that said at least one protective screen (18) is microporous and has pores with an average opening of less than 1 µm. 3) Footwear, according to one or more of the preceding claims, characterized in that said at least one protective screen (18) comprises a sheet of material obtained from a substantially homogeneous mixture composed of - a high molecular weight polyolefin, in a percentage concentration by volume of said mixture between 8% and 98%, - a filler capable of promoting the formation of micropores, in a percentage concentration of the volume of said mixture between 1% and 92%, - a plasticizer, in a percentage concentration of the volume of said mixture between 1% and 40%. 4) Footwear, according to claim 3, characterized in that said polyolefin is a UHMW polyethylene, acronym of the English term Ultra High Molecular Weight. 5) Footwear, according to one or more of claims 3 and 4, characterized in that said filler is selected from silicic anhydride and silicic acid, an oil insoluble in water being said plasticizer. 6) Footwear, according to claim 1, characterized in that said at least one protective screen (18) is made of a material selected from polytetrafluoroethylene, polyurethane, polyester, polypropylene, polyethylene and the like. 7) Footwear, according to claim 6, characterized in that said at least one protective screen (18) has a structure chosen from - a structure consisting of a single integral layer substantially between 0.1 mm and 5.0 mm thick, - a structure consisting of a plurality of layers joined by lamination to form a multilayer element with a thickness substantially between 0.1 mm and 5.0 mm, - a structure consisting of a plurality of laminated layers, a permeable material cohesive with them being provided between them. 8) Footwear, according to one or more of the preceding claims, characterized in that said periphery (16b) of said at least one membrane (16) is waterproofly sealed to said body (13). 9) Footwear, according to one or more of the preceding claims, characterized in that said at least one protective screen (18) is waterproofly sealed to said body (13), in correspondence with said at least one area (13a) of said body (13) ), peripheral to said at least one region (15), by gluing. 10) Footwear, according to one or more of claims 1 to 8, characterized in that the material forming at least one component of said body (13) is co-molded on said at least one protective screen (18) to cling to it with a waterproof seal in correspondence with said at least one region (13a) of said body (13), peripheral to said at least one region (15). 11) Footwear, according to one or more of the preceding claims, characterized in that it comprises a permeable spacer element (20), superimposed at least partially on said membrane (16) to protect it. 12) Footwear, according to one or more of the preceding claims, characterized in that it comprises a lower part (21) and an upper part (22) of the body (13), being said at least one protective screen (18) sealed to said lower part (21) presenting said at least one region (13a) peripheral to said at least one region (15). 13) Footwear, according to claim 12, characterized in that said protective screen (18) has a perimeter band (18a), uncovered by said protective element (17) and said membrane (16), said protective screen (18) being , in correspondence with said perimeter band (18a), associated with a waterproof seal to said upper part (22). 14) Footwear, according to one or more of claims 12 and 13, characterized in that said upper part (22) has a central portion having through holes or openings defining part of said region (15). 15) Footwear, according to one or more of the preceding claims, characterized in that the upper assembly (11) comprising at least one breathable, external upper (23) and a breathable lining (24), and an insole (25) breathable, comprising said membrane (16), the lower flaps of said at least one upper (23) and said at least one lining (24) being joined to said insole (25), and said body (13) being also connected to a waterproof seal - below said periphery (16b) of said at least one membrane (16), and - to said at least one protective screen (18) in correspondence with said zone (13a), peripheral to said region (15) permeable to water vapor.