| 摘要 |
1,214,778. Polyurethane adhesive for textiles. FARBENFABRIKEN BAYER A.G. 28 May, 1969 [30 May, 1968; 11 April, 1969], No. 26888/69. Heading B5N. [Also in Division C3] Textile materials are heat sealed using a polyurethane adhesive which has a softening point of e.g. 80-200‹ C. and is prepared by reacting (a) one or more aliphatic diisocyanates, (b) one or more glycols which have aliphatically bound hydroxyl groups and a molecular weight of up to 400, (c) 0À1-10% wt. of either (i) one or more alcohols containing at least three OH groups and having M.W. of up to 400, or (ii) a polyisocyanate having at least 3 aliphatically bound NCO groups and a M.W. of up to 700. A wide range of reagents (a), (b) and (c) are specified. The polyurethane may be prepared either in solution from which it may be extracted by precipitation or spray drying or in a melt. The product may be granulated and applied to the textile as a powder. The polyurethane may also be applied in the form of sheets, threads, fabrics, fleeces or pastes or sprayed on as a dispersion or solution. The heat sealing is suitably effected by subjecting the applied polyurethane to I.R. radiation to raise the temperature to 80-200‹ C., placing the second textile sheet over the softened adhesive and bonding in an ironing press at 130‹ C. and 0À04 kg./cm.<SP>2</SP>. Woven or knitted fabrics, felts or fleeces of cotton, rayon, wool or of polyacrylonitrile, polyamide or polyester fibres may be heat sealed by this method. |
