GB1063876A - Improvements in or relating to the stiffening of shoes - Google Patents

Abstract

A stiffener suitable for incorporation in the toe or heel end portion of a shoe upper is made from an elastomeric copolymer of ethylene and an alkyl acrylate, preferably ethyl acrylate. The copolymer may be used as follows: (a) it may be applied directly, as a molten mass, to the inner surface of the outer integument of the upper, (b) it may be injection or compression moulded to the required shape, or (c) it may be extruded into a sheet from which stiffener blanks may be cut, the edges of the blanks then being skived. In cases (b) and (c) an adhesive may be applied to one or both surfaces of the stiffener, depending on whether the shoe is lined or not, and the surfaces to which adhesive is applied may be oxidized, for example by the action of chromium trioxide and sulphuric acid, by an oxidizing flame or by corona discharge. In case (c) a copolymer may contain a filler such as wood flour, cotton, viscose or other short fibres, which are exposed along the skived margin of the stiffener. The adhesive composition may be a heat or solvent activatable cement such as neoprene, a polyacrylate or polyvinyl acetate or a pressure sensitive adhesive such as polyisobutylene or an aqueous emulsion of natural rubber and a resin ester in which case the coated surfaces are covered with a strippable protective paper. When making an unlined shoe the inside surface of the stiffener may be laminated to a sheet of decorative materal e.g. flocked fabric.