- EVA in the range of 20% to 60%;
- rubber in the range of 25% to 70%;
- bulking agent in the range of 6% to 12%;
- foaming agent in the range of 0.5% to 12%;
- bridging agent in the range of 1% to 5%; and
- color master agent in the range of 0% to 2%.

In some embodiments of the footwear sole and/or the footwear item, and/or the method aspects of the invention, the composition comprises:

- EVA in the range of 42% to 46%;
- rubber in the range of 38% to 42%;
- bulking agent in the range of 6% to 8%;
- foaming agent in the range of 6% to 10%;
- color master agent in the range of 0.5% to 1.5%; and
- bridging agent in the range of 1% to 3%.

- 44% EVA;
- 40% rubber;
- 6% bulking agent;
- 8% foaming agent;
- 1% color master agent; and
- 1% bridging agent.

In some embodiments of the footwear sole and/or footwear item, and/or the method aspects of the invention, the composition comprises:

- ethyl vinyl acetate (EVA) in the range of 57% to 60%;
- rubber in the range of 28% to 32%;
- bulking agent in the range of 6% to 8%;
- foaming agent in the range of 1% to 5%;
- color master agent in the range of 0.5% to 2%; and
- bridging agent in the range of 1% to 2.5%.

- 59% EVA;
- 30% rubber;
- 6% bulking agent;
- 3% foaming agent;
- 1% color master agent; and
- 1% bridging agent.

- EVA in the range of 20% to 22%;
- rubber in the range of 66% to 70%;
- bulking agent in the range of 6% to 8%;
- foaming agent in the range of 0.5% to 3%;
- color master agent in the range of 0.5% to 2%; and
- bridging agent in the range of 1% to 2.5%.

- 20% ethyl vinyl acetate (EVA);
- 70% rubber;
- 6.2% bulking agent;
- 0.8% foaming agent;
- 1.5% color master agent; and
- 1.5% bridging agent.

In some embodiments of the footwear sole and/or the footwear item, product and/or the method aspects of the invention, the composition consisting essentially of:

- EVA in the range of 20% to 60%;
- rubber in the range of 25% to 70%;
- bulking agent in the range of 6% to 12%;
- foaming agent in the range of 0.5% to 12%;
- color master agent in the range of 0% to 2%; and
- bridging agent in the range of 1% to 5%.

The footwear soles and/or the footwear items, composed of a single layer of the composition described herein, are characterized by unique and improved properties. For example, footwear sole and footwear item of the invention has a stable cushioning property measured as compression set. According to some embodiments of the invention, the compression set value is not more than 30%, thus, bubbles (foamed cells) in the footwear sole are restored to original state every time they are subject to impact compression due to weight imposed by the wearer (for example, during walking, running and/or the like), and a stable cushioning property of the sole is maintained.

Some embodiments of some aspects of the invention, provide a footwear sole and/or a footwear item characterized by having at least one property selected from:

Skid resistance of dry in the range of u 0.30 to u 0.80, and wet in the range of u 0.35 to u 0.60 (e.g., when worn on a wet surface and dry surface), determined according to F2913-2011;

Shore A hardness in the range of 20H to 35H, determined according to ASTM D2240, in some embodiments 23H to 30H, or 25H to 30H, or 25H to 28H;

Shore C hardness in the range of 35H to 48H, determined according to ASTM D2240, in some embodiments 35H to 45H, or 40H to 43H;

Compression set of not more than 30%, determined according to SATRA TM156:2002,620n. In some embodiments, the compression set is not more than 20%. In some embodiments, the compression set is in the range of 4 to 25%, or 6 to 20%, or 8 to 18%, or 4 to 18% or at most 15%, or at most 12%.

Density in the range of 0.2 to 0.7 mg per cubic meter (mg/m³), determined according to ASTM D297. In some embodiments, the density is in the range of 0.24 to 0.6 mg/m³, or 0.25 to 0.52 mg/m³, or 0.272 to 0.489 mg/m³, or 0.3 to 0.45 mg/m³, or 0.25 to 0.35 mg/m³, or 0.25 to 0.30 mg/m³.

Abrasion resistance in the range of about 0.1 to about 0.5 g after 10,000 cycles, determined according to ASTM D3886-99. In some embodiments, the abrasion resistance in the range of about 0.2 to about 0.5 g after 10,000 cycles, or about 0.2 to about 0.4 g, or about 0.1 to about 0.5 g.

Some embodiments of some aspects of the invention provide a method of preparing a footwear sole composed of a single unitary layer. In some embodiments, the method comprises a step of forming, by mixing while heating, a molten composition comprising: ethyl vinyl acetate (EVA), rubber, and at least one agent selected from a bulking agent and a foaming agent. In some embodiments, the constituent components of the desired compositions (e.g., EVA, rubber, foaming agent, bridging agent, and color) are blended together to create a mixture of homogenous pellets, granules, or both, e.g., the components are mixed and melted to form a uniform blend of the various components.

The forming of a molten composition may be carried out at a temperature in the range of 70 to 110° C., or 75 to 100° C., or 80 to 110° C., or 90 to 100° C., or 90 to 95° C., or 85 to 95° C., to provide a homogeneous composition.

Foaming agent and/or a bulking agent may be utilized to decrease the weight of a sole component. Foaming may be utilized to introduce gas into the sole composition during the process of the invention. In some embodiments, foaming may be used to decrease the weight of the composition while allowing for filling of the mold with a required volume of molten composition with less dense solid matter.

Thus, the footwear sole and/or the footwear item may be manufactured in a single-step process (e.g., single-shot molding). A single step process is advantageous since it allows a more efficient manufacturing process as the composition is subjected to a single heating process, thus enabling shrinkage management. Multiple reheating may cause the composition to become unstable and thus managing shrinkage on the end product sole may be more challenging.

In some embodiments, the method comprises one or more of: injection molding, compression molding and single-step molding.

After the molten composition forming step, the molten composition is inserted in to a mold (e.g., by injecting the molten composition into a two part mold at the temperature range) and heated to a temperature in the range of 130 to 190° C.; to form and optionally cure the footwear sole and/or the footwear item. In some embodiments of the method of the invention, the molding step is carried out at a temperature in the range of 140 to 190° C., or 150 to 190° C., or 160 to 185° C., or 170 to 180° C.

After the molding step, the mold is cooled to a temperature in the range of 130 to 160° C., or 135 to 150° C., or 140 to 145° C., to form a footwear sole and/or footwear item.

The formed footwear sole and/or footwear item is then removed from the mold, e.g., after cooling the mold to about 25 to 40° C., or 25 to 30° C., e.g., for a duration of time in the range of 5 to 30 minutes, or 5 to 15 minutes.

Molding and/or curing cycle times of the invention can exceed 10 minutes, or 15 minutes, or 20 minutes, which is advantageous in comparison to typical footwear sole and/or footwear sole manufacturing process cycle times of under 2 minutes, since the exceeded time duration allows for obtaining advantageous thicknesses in a continuous and single step process. In some embodiments, the sole forming step comprises forming a cross-linked foamed sole, by foaming while curing the molten composition in the mold.

In some embodiments of the method of the invention, the molding step is carried out simultaneously during the curing and/or the foaming process steps to allow the molten composition to expand and/or cure simultaneously during the molding and then be removed from the mold, e.g., by utilizing a suitable curing agent and/or foaming agent, heating temperature range, time duration, pressure, cooling temperature range, etc. This is advantageous since the composition and/or method of the invention, provide a single sole (and/or outsole and/or footwear item) that provides a combination of unique features described herein.

In some embodiments, the method further comprising a two-step cooling step after the molding step, wherein the first cooling is to a temperature in the range of 130 to 160° C. for a duration of time in the range of 5 to 20 minutes, and the second cooling is to about room temperature for a duration of time in the range of 5 to 30 minutes.

The footwear sole and/or footwear item is characterized by having a thickness in the range of 15 to 40 mm, or 17 to 35 mm, or 20 to 30 mm, or 18 to 28 mm, which is provided due to the composition and/or the method of the invention.

Next, the footwear sole is further shaped with a shoe last to form the sole. In some embodiments, a cover mold is used for application of flock. A primer, and then optionally glue are sprayed on a bottom of the sole using the cover mold. Flock is then dusted onto the glue. Finally, the excess flock is removed from the glued surfaces.

The method steps may be performed in a different order. In some embodiments, some steps are excluded, and/or some steps are performed multiple times.

The sole formed from this unique and inventive method has properties not found in other footwear soles. Specifically, a sole100 formed from this unique and inventive rubber compound, that includes a combination of EVA and rubber can provide a softness and rebound (e.g., retention of original shape of the sole after repeated compression). In addition increased flexibility, compression resistance, light weight and durability are provided.

In some embodiments, the sole obtained from the above method is generally homogeneous, e.g., the sole is formed from a uniform blend of the various components in the composition.

In some embodiments of the footwear sole and/or footwear item and/or method aspects of the invention, the thickness of the layer obtained is in the range of 10 to 50 mm, or 15 to 35 mm, or 18 to 35 mm, or 18 to 29 mm.

Reference is now made toFIGS. 1-4, which depict various views of afootwear sole100, according to some embodiments of the invention.

FIG. 1 shows a top view of afootwear sole100, in accordance with embodiments of the invention. As used herein, the term “footwear” means a device or item worn on a user's foot, for example, a shoe. Non-limiting examples of footwear may include a slipper, a sock, a ballet slipper, a sport shoe, a sandal, a boot, a dress shoe, and the like. Other examples of footwear, as are known to those of skill in the art, can also be included.

As used herein, the term “sole” can be a unitary sole, an insole, outsole, or any combination thereof, with or without additional components added.

Sole

100 is formed of a sole compound that is described in further detail below. In some embodiments,Sole100 includes atop surface8 including afront portion10, amiddle portion12, and arear portion14. Thefront portion10 is proximate the area where a wearer's toes would be located, therear portion14 is proximate the area where a wearer's heel would be located, and themiddle portion12 is located between thefront portion10 andrear portion14. In some embodiments,grooves20 are disposed intop surface8 of thefront portion10 of sole100. In some embodiments,grooves20 can be arranged in a substantially parallel arrangement, extending away from one side of the sole100, towards the other side. In some embodiments, sole100 can include fourgrooves20. In some embodiments, other arrangements ofgrooves20 can be used. In some embodiments, sole100 does not include anygrooves20.

Apertures

30 are also defined intop surface8 of sole100.Apertures30 can allow for sole100 to be lighter, while also providing some cushioning benefits.Apertures30 can be arranged in rows. In some embodiments, sole100 includes rows ofapertures30. Each row can include three or fourapertures30. Additionally or alternatively, in some embodiments, different configurations ofapertures30 can be used. In some embodiments, noapertures30 are defined in sole100.

In some embodiments, the footwear sole comprises a top surface, the top surface including a plurality of apertures defined in a rear portion of the top surface. In some embodiments, the plurality of apertures are defined in a tapered shape, and a first aperture of the plurality of apertures has a depth that is less than a second aperture of the plurality of apertures.

FIG. 2 shows a bottom view of afootwear sole100. In some embodiments, recessedgrooves42 are defined in abottom surface40 of sole100. Recessedgrooves42 can provide traction while walking on smooth or wet surfaces. Recessedgrooves42 can be formed in a chevron or zig-zag pattern. Alternatively, other patterns can also be used. Thegrooves42 can end with the recess raising to thebottom surface40.Sole100 can include a sidewall that extends beyond a walking surface ofbottom surface40. Additionally or alternatively, in some embodiments, different configurations ofgrooves42 can be used. Additionally or alternatively, in some embodiments, nogrooves42 are defined inbottom surface40 sole100.

Additionally or alternatively, in some embodiments, thetop surface8 of the sole100 further including a plurality of grooves defined in afront portion10 of thetop surface8.

Additionally or alternatively, in some embodiments, thefootwear sole100 comprising abottom surface40, including a plurality of recessed grooves defined therein.

In some embodiments, the sole100 integrally comprises one or more of an arrangement of grooves, recessed grooves apertures and protrusions within thesole layer100.

FIG. 3 shows a side view of afootwear sole100. In some embodiments,grooves42 can extend to an outer edge of sole100. Thegrooves42 can end with the recess, raising to the surface of the edge of sole100.

FIG. 4 shows a cross-sectional view of sole100 taken along line X-X ofFIG. 1.Apertures30 can include a tapered shape, withdifferent apertures30 having different depths. In some embodiments, theapertures30 can all have the same depth. Additionally or alternatively, in some embodiments, different arrangements ofapertures30, or noapertures30, can be used.

While the sole100 has been described herein as including certain features, such as, by way of non-limiting example,grooves20,apertures30 and/or recessedgrooves42, embodiments of the invention can be directed to a sole100 that does not include one or more of these and other described features, or other combinations of these features. Further, some embodiments, sole100 can include other features, not described herein.

FIG. 5 shows a view of afootwear item300, including a sole100 and an upper200. Withfootwear item300, sole100 is attached to upper200 in a manner known to those of skill in the art. By way of certain embodiments,footwear item300 can take various forms, such as that of a slipper, a sandal, a boot, as well as other forms.FIG. 6 shows a view of afootwear item400, including a sole100.Footwear item400 can be, for example, a boot. In some embodiments, a boot, such as a waterproof rain boot (or other type of boot) can be formed substantially entirely from the above-described sole compound. Additionally or alternatively, in some embodiments, a rain boot sole and upper could be formed with other portions of the boot, such as a boot shaft or zipper being added to the portions formed with the sole compound. The other portions may be made from materials other than the sole compound.FIG. 7 shows a view of afootwear item500, including a sole100. An upper can be attached to sole100.Footwear item500 can be, for example, a ballet slipper.

Further, by forming the sole100 as a single layer, sole100 can deliver cushioning and support similar to that delivered by the use of multiple layers/densities of various cushioning materials, as is typical in current footwear soles and/or products. The present inventive sole100 also eliminates the need for a separate outsole as well. This feature contributes to reduced costs and complexities in the manufacturing process. In addition, a sole formed with the above-discussed compound is lightweight, which is beneficial to the wearer. The sole100 can also be waterproof.

In some embodiments, a separate top member is disposed on thetop surface10 of the sole100. Some examples of such materials having elastic and/or rebounding properties include: silicon, polyester, neoprene, natural rubber foams, synthetic rubber foams, polyurethane, polyether and polyester foams, styrene-butadiene rubber (SBR), polyethylene (PE), EVA, as well as other cushioning materials known or used by one skilled in the art, such as memory foam. Additionally or alternatively, the top element may comprise a layer of natural materials, such as leather, cotton, felt, linen, and other such materials known to one skilled in the art.

Additionally or alternatively, in some embodiments, a separate cover layer can cover all or a portion of the sole100. In some embodiments, the cover layer can be formed of a fabric.

In some embodiments, a footwear item, including sole and upper portions, can be formed from the sole compound in, for example, a single-shot molding process. For example, a waterproof rain boot (or any other type of boot) could be formed substantially entirely from the sole compound. Additionally or alternatively, in some embodiments, a rain boot sole and upper could be formed with other portions of the boot, such as a boot shaft or zipper being added to the portions formed with the sole compound.

In some embodiments, the footwear item can be a slipper, ballet slipper, or other form of footwear item.

In addition, due, in part, to the combination of EVA and blowing agent in the above-discussed rubber compound provides for alight weight sole100, while still allowing for forming the sole in a mold. The sole100 is durable, in part, due to the characteristics of the rubber contribute to cushioning and durability. Thus, a sole100 as described herein is light comfortable and durable.

Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting. In addition, any priority document(s) of this application is/are hereby incorporated herein by reference in its/their entirety.