| 摘要 |
1346847 Bonding moulded shoe treads BRITISH UNITED SHOE MACHINERY CO Ltd 6 May 1971 [7 May 1970] 13456/71 Heading B5A [Also in Division A3] An adhesive-attachable polyurethane tread member for a shoe is made by moulding a mixture comprising an organic compound having at least two active hydrogens per molecule and an organic compound having at least two -NCO groups per molecule for reaction with the first compound to form a polyurethane, and, when the mixture has reacted and solidified, applying an adhesive to a surface of the tread member not more than twentyfour hours after the solidification thereof. This period should be less than four hours unless the mould is formed of resinous material to which the moulded polyurethane will not adhere, such as polytetrafluoroethylene or polytrifluorochloroethylene. A silicone mould release material may also be used. The polyurethane is preferably formed from a mixture of diols having a molecular weight between 1500 and 3500 and low molecular weight diamines with isocyanates, preferred examples being given, and foaming agents such as water or volatile halogenated organic liquids may be included. Suitable catalysts are specified. The adhesive compositions which may be applied, preferably in a layer between 0À005 and 0À05 inch thick, include volatile organic solvent solutions of heat-softenable high polymer materials, e.g. linear polyurethanes or synthetic elastomers such as polychloroprene or acrylonitrile-butadiene copolymers, and a phenol aldehyde resin may be included. Preferably the solvent includes a swelling agent for the moulded polyurethane, e.g. tetrahydrofuran or dimethylformamide, and also swelling agents for the adhesive polymer. In examples a tread member has adhesive applied around the peripheral region of one face ; this is subsequently activated by radiant heat and bonded to a heated shoe upper. A further adhesive may be interposed and may be applied either to the tread member or the upper. |
