Process for the preparing a hot water soluble window film for reclaimed window mail envelope and a reclaimed window mail envelope provided with said film

摘要

PURPOSE: A method for preparing a water-soluble film for a recyclable postal envelope and a recyclable postal envelope adhered with the film are provided, to obtain the film which isn't dissolved or swollen in water of 10-35 deg.C and is dissolved in water together with an envelope when added in a waste paper recycling bath. CONSTITUTION: The method comprises the steps of adding at least one selected from the group consisting of a polyacrylate emulsion synthetic resin selected from poly(methyl methacrylate) emulsion synthetic resin, poly(methyl acrylate) emulsion synthetic resin, poly(ethyl methacrylate) emulsion synthetic resin, poly(ethyl acrylate) emulsion synthetic resin, poly(butyl methacrylate) emulsion synthetic resin, poly(butyl acrylate) emulsion synthetic resin, polyacrylonitrile emulsion synthetic resin and copolymer emulsion synthetic resin, a polystyrene homopolymer or copolymer emulsion synthetic resin, a vinyl acetate-based copolymer emulsion synthetic resin, an ethylene-vinyl acetate-based copolymer emulsion synthetic resin and a polyurethane emulsion synthetic resin to a poly(vinyl alcohol) aqueous solution in the ratio of 100 : 1-200 by weight (solid component) to prepare a homogeneous solution; and applying the obtained solution to a releasing paper with a film applicator and drying it to prepare the film. Preferably the film has a thickness of 10-50 micrometers.