Processes for improving the properties of foils, films, fibres or the like made from alginic acid or water-insoluble alginates

摘要

Foils, films, fibres or the like made from alginic acid or water-insoluble alginates are stabilised by treating them with a solution containing a partly condensed formaldehyde synthetic resin which is then hardened to form the finished resin therein. Urea-formaldehyde resin is preferably used in aqueous solution of low molecular weight and in proportion to introduce less than 10 per cent by weight of resin into the alginic material. Resins from cyanamide, dicyandiamide, melamine, acetoneformaldehyde and phenol-formaldehyde condensation products may also be employed. The treated products are resistant to atmospheric humidity and patterned effects may be produced in them by embossing the treated foils or fabrics prior to the final hardening. Crimping may similarly be produced in fibres. Opalescent and matt effects may also be produced, and shrinkage reduced by the process. Uncondensed reagents as described in Specification 467,480 may be employed in place of the lightly-condensed resin solutions.