Waterproof footwear and method for its production

Abstract

Footwear, having an upper (13), which is constructed with an outer material (17) having an outer-material end region (27) on the sole side and with a waterproof functional layer (19) which is arranged on the inner side of the outer material (17) and has a functional-layer end region (23) on the sole side; an inner sole (15) and a joining device (25) which joins the outer-material end region (27) to the inner sole (15), around at least part of the periphery of the upper and allows for a space (33; 33a; 33b) to be left between the outer-material end region (27) and the inner sole (15), in such a manner, that the joining device (25) can be flowed through by sealing material (37; 39) that is liquid during application; the functional-layer end region (23) extending at least into the region of the joining device (25) and being sealed in a waterproof manner by sealing material (37; 39) which has passed through the joining device (25) to the functional layer (19) during production of the footwear.

Description

BACKGROUND OF THE INVENTION [0001] The invention relates to footwear with an upper, which is constructed with an outer material and a waterproof functional layer arranged on the inner side of the outer material, an outer-material end region on the sole side being joined to an inner sole and a functional-layer end region on the sole side being sealed by a sealing material leading to waterproofness. An example of footwear of this type is known from the applicant's EP 0 298 360 B1. [0002] The invention also relates to a method for producing footwear of this type. [0003] In the case of the footwear according to EP 0 298 360 B1, the outer-material end region ends at a predetermined distance from an inner sole serving as an insole, this distance being bridged by a gauze strip through which liquid material can flow, one longitudinal side of which is sewn to the outer-material end region and the other longitudinal side of which is sewn to the insole. One end of the functional layer on the s...

AI Technical Summary

Benefits of technology

[0006] The present invention provides footwear with which such problems can be overcome, which is inexpensive, can be handled more easily during production, including at points with small radius of curvature, and leads to good waterproofness.

[0008] Footwear according to the invention comprises an upper, which is constructed with an outer material having an outer-material end region on the sole side and with a waterproof functional layer which is arranged on the inner side of the outer material and has a functional-layer end region on the sole side. What is more, such footwear has an inner sole and a joining device which joins the outer-material end region to the inner sole, which runs around at least part of the periphery of the upper, and which allows for a space to be left between the outer-material end region and the inner sole in such a manner, that it can be flowed through by sealing material that is liquid during application. The functional-layer end region extends at least into the region of the joining device and is sealed in a waterproof manner by sealing material which has passed through the joining device during production of the footwear.

[0017] In the case of footwear with a joining device according to the invention, in the form of a seam, only a single joining seam is required in the region of the connection between the outer material and the inner sole, said joining seam also being entirely unproblematical even at those points at which the inner sole has a small radius of curvature. All that is required in comparison with footwear with a conventional seam, as shown for example in FIG. 1 of the already cited EP 0 298 360 B1, is to design the seam in such a way that it can be flowed through by liquid material, i.e. has or allows (for example by extending) a distance between the outer material and the inner sole through which liquid sealing material can flow against a zone of the functional layer located in the region of the joining device and, as a result, the said zone can be sealed by the sealing material.

[0025] Reactive hot-melt adhesive has, on the one hand, particularly great creepability in the liquid state before fully reacting and, on the other hand, brings about particularly high and permanent waterproofness in the fully reacted state. The reactive hot-melt adhesive can be applied with very simple means, for example be brushed on, sprayed on or applied in the form of a strip of adhesive or a bead of adhesive, the reactive hot-melt adhesive being made tacky by heating and, as a result, allowing itself to be attached to the region to be sealed before the full reacting process and accompanying permanent adhesive bonding to the functional layer begins.

[0035] In one embodiment of the invention, a functional layer which is not only water-impermeable but also water-vapour-permeable is used. This makes it possible to produce waterproof shoes which remain breathable in spite of the waterproofness.

[0041] If ePTFE is used as the functional layer, the reactive hot-melt adhesive can penetrate into the pores of this functional layer during the cementing operation, which leads to a mechanical anchoring of the reactive hot-melt adhesive in this functional layer. The functional layer consisting of ePTFE may be provided with a thin polyurethane layer on the side with which it comes into contact with the reactive hot-melt adhesive during the cementing operation. If PU reactive hot-melt adhesive is used in conjunction with such a functional layer, there occurs not only the mechanical bond but also a chemical bond between the PU reactive hot-melt adhesive and the PU layer on the functional layer. This leads to a particularly intimate adhesive bonding between the functional layer and the reactive hot-melt adhesive, so that particularly durable waterproofness is ensured.

Problems solved by technology

The sewing of the gauze strip on its two longitudinal sides requires a certain effort, with corresponding consequent costs.

What is more, at points at which the insole has a small radius of curvature, in particular in the case of children's shoes, it is not always that easy to sew the gauze strip without any folds.

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