| 摘要 |
A reinforcing/stiffening material, e.g. for use in the manufacture of shoe upper components, comprises a fabric layer impregnated with an impregnant. The impregnant comprises a stiffening component and a water-soluble component in quantities such that when the material is immersed in water it is rendered flaccid and hardens to a stiffening consistency when dried. Suitable stiffening components are polyvinyl acetate or one or more copolymers thereof, polyvinyl pyrolidone, one or more acrylates, one or more methacryltes, and styrene-butadiene rubber. Suitable water-soluble components are polyvinyl alcohol, one or more soluble acrylates, one or more soluble methacrylates, starch and dextrin. According to the proportion of water-soluble component used, an adhesive coating may be applied to one or both sides of the material. The impregnant may also comprise a hardening component which undergoes a chemical reaction when immersed in weak acid solution whereby it is rendered flaccid when in a wetted state and dries to a hardened condition. The impregnant may further comprise a filler by which the water absorption rate of the material in enhanced, and an additive or additives for limiting the amount of water taken up by the material. |
