| 摘要 |
<p>Method comprises mixing a finely powdered ferromagnetic material (I) with a colour paste such as ink or paint, and applying the resulting colour paste to a substrate. (I) is e.g. Fe powder. The ferromagnetic-treated colour paste is applied, e.g. by screen printing and may be overcoated with a layer of colour paste which is free of (I). The compsn. contg. the (I) may also be applied to the reverse side of a thin plastic film such as a PET film, or it may be applied to a previously-formed layer of a coherent material such as plastisol which after drying or hardening can be removed from the substrate. In a further embodiment, the magnetic compsn. is applied to a self-adhesive substrate. The prods. are esp.useful as temporary notice boards, sales display signs, advertisements, labels, etc. and are easy and economical to make. They may be pre-magnetised in a magnetic field and are e.g. in the form of sheets, plaques, cards or boards which may be pre-printed with certain information, and to which magnetic letters, numbers and symbols can be adhered and removed as necessary, e.g. for indicating changes in selling price on a pre-printed sales card. Alternatively the magnetic compsn. may be printed onto a substrate in the form of letters or other symbols which will adhere to a magnetic substrate or which may be pre-magnetised.</p> |
