Patent DE-19938139-A1 (DE)
Title: Waterproof footwear has reactive hot-melt adhesive to bond sole to extended length of function layer at upper material to give watertight sealing around sole
Inventor: HAIMERL FRANZ XAVER
IPC: A43B9/12
Filed: 1999-08-16
Abstract: The footwear has a sole (19) which is bonded to the end (61) of the upper by an adhesive at least at the sealing for the end (23) of the waterproof function layer, using a reactive hot-melt adhesive (33) which is watertight when activated.  The end (23) of the function layer is extended into a projection (24), to bear against the sole adhesive (33) over the whole width of the extended length (24). The end (61) of the upper is generally parallel or at right angles to the surface of the sole (19), and the end (23) of the function layer projects over the end (21) of the upper material. The end (23) of the function layer is bonded to an insole by a seam or a pinched adhesion bond (25). The function layer can be held by one or two draw cords parallel to the sole (19) surface. The end (21) of the upper material is bonded by an adhesive to the end (23) of the function layer. The projecting end (24) is bridged by a netting strip, secured on one side to the end (21) of the upper material and to the insole (17) or the draw cord at the other side. The sole adhesive uses a reactive hot-melt adhesive (33) at least in a closed part-zone round the sole. The upper material (13), at least in the adhesion part-zone, can be penetrated by the adhesive (33) which also gives an adhesive seal for the function layer (15). The end (61) of the upper has an end edge with an inner zone free of the upper material, to take in the adhesive (33) between the under side (27) of the insole (17) and the end (21) of the function layer, forming a closed adhesive bonding round the sole, taken into the pinch adhesion bonding (25). The function layer is part of a multi-layer laminate. The end (61) of the upper can be held by a draw cord parallel to the surface of the sole (19). The sole (19) is flat, or in a shell structure with vertically upright side walls. The sole (19) is bonded to the sealing zones of the function layer (15) by a reactive hot-melt adhesive (33) and it has a conventional sole adhesive for other zones. The upper surface (31) is coated with the reactive hot-melt adhesive (33) over the whole surface area in contact with the upper (11). The reactive adhesive can be foamed. A netting strip can be between the insole (17) and the end (61) of the upper, with one side edge bonded to the insole, and the other side edge bonded to the end (21) of the upper material and also with the end (23) of the function layer. The netting strip is stitched to the insole (17), the end (21) of the upper material and the end (23) of the function layer. The sole adhesive is a reactive hot-melt adhesive (33) round the sole, working with the netting strip, in a closed zone, and the adhesive can be foamed. A filler is between the under side (27) insole (17) and the upper side (31) of the sole (19). A bonding adhesive glues the end (21) of the upper material and the end (23) of the function layer together. An Independent claim is included for a footwear manufacturing process where, at least round the sole, a reactive hot-melt adhesive (33) is applied against the extended length of the upper structure after the sole is adhesive bonded.  Preferred Features: The upper material (13) has a porosity, at least at the bonding zone, to allow the reactive hot-melt adhesive (33) to penetrate through it while it is in a fluid state, to give a sealed bonding with the function layer (15). The end (61) of the upper has an edge zone, with a zone free of upper material, to take up the reactive hot-melt adhesive (33) and be pressed in place. The reactive hot-melt adhesive (33) is applied over the whole surface of the sole (19), or at part-zones round the outer side of the upper and the zones to be sealed. The adhesive can be activated by wetting and heat, as a thermoplastic. The position of the end (21) of the upper material is fixed before bonding to the sole (19) at the end (23) of the function layer. An open-pore adhesion grip material covers the whole or part of the footwear and the sides. The reactive hot-melt adhesive, in a width of 1 cm, gives an overlap between the insole and the pinched upper.