| 摘要 |
904,424. Coated regenerated cellulose film. BRITISH CELLOPHANE Ltd. May 8, 1961 [May 26, 1960], No. 18687/60. Class 140. A mould-growth inhibiting wrapping material comprises a regenerated cellulose film incorporating a water-soluble salt of sorbic acid, coated on one surface only with a coating of a moisture-proofing and/or heat-sealable coating composition. The amount of the salt of sorbic acid incorporated in the film may be less than the amount at which the salt crystallizes out of the film. The salt may be sodium, ammonium or potassium sorbate and may be present in amount not exceeding 22 parts by weight based upon 100 parts by weight of the film. The coating composition may contain a vinylidene chloride copolymer, e.g. vinylidene chlorideacrylonitrile, vinylidene chloride-methyl methacrylate, polyethylene, polypropylene, or a filmforming nitrocellulose composition with or without a moisture-proofing wax component. The regenerated cellulose film may be treated with an anchoring agent, e.g. the reaction product of a water-soluble polyamide with epichlorhydrin, partially condensed urea-formaldehyde or melamine-formaldehyde or mixtures of both, or polyalkylene imines, to enhance the adhesion of the coating composition. The wrapping material may be produced by impregnating a freshly-formed regenerated cellulose film in the gel state with an aqueous solution of a water-soluble salt of sorbic acid, drying the film, and applying a moisture-proofing and/or heat-sealable coating composition to one side of the film. Two freshly formed regenerated cellulose films in the gel state may be brought into continuous intimate contact to form a composite film, impregnated with an aqueous solution of a water-soluble salt of sorbic acid, dried, and a moisture-proofing and/or heatsealable coating composition applied to both sides of the composite film prior to separating the two films. The water-soluble salt of sorbic acid may be incorporated in a conventional softener and/or anchoring-agent treatment bath. Specification 771,400 is referred to. |
