| 摘要 |
968,049. Coated films. E. I. DU PONT DE NEMOURS & CO. Nov. 26, 1962 [Nov. 28, 1961], No. 44683/62. Heading B2E. Coated non-fibrous films are produced by drying a film of gel hydrophilic material, applying to it a liquid coating composition containing an organic polymeric material in a liquid medium which swells the hydrophilic film, and subsequently drying the coated film, wherein the uncoated gel film 11 is dried to a mositure content of 75-15% based on the dry weight of the hydrophilic material by contacting it with a heated supporting surface, e.g. heated dryer rolls 17 in compartment 15, after which the drying is continued, e.g. by means of infra-red heaters 23, 24 in compartment 16, to a moisture content of 1-10%, by passing the film through at least one span in which it is heated while out of contact with a heated surface. The hydrophilic material may be regenerated cellulose, hydroxyethyl or hydroxypropyl cellulose, polyvinyl alcohol or partially hydrolysed ethylene-vinyl acetate copolymer. The organic polymeric material may be a cellulose derivative, polyamides, polyesters, polyolefins, and copolymers of vinyl chloride and vinylidene chloride, examples of which are given. The coating composition may be an aqueous dispersion or a solution in an organic solvent. The aqueous dispersion of the vinylidene chloride copolymer may also contain a polyhydric alcohol, examples of which are given. The wet gel film may be impregnated in tank 12 with a softener and an anchoring agent, examples of which are given, before it is dried and coated.
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