912,064. Laminates. COLODENSE Ltd. June 23, 1961 [July 27, 1960], No. 26133/60. Class 140. A wrapping material comprises a sheet of regenerated cellulose and a sheet of paper secured together by a coating of a vinylidene copolymer composition applied to one or both sheets, both sheets being precoated on their outer surfaces with the same composition. Adhesion is secured by heat and pressure, preferably that of a pair of rollers, one of which is of steel internally heated and preferably coated with a silicone release agent or with P.T.F.E., the other being of silicone rubber. The paper used may be vegetable parchment, glazed imitation parchment, glassine or greaseproof paper. The coating and adhesive composition may comprise at least 80%, preferably 90%, of vinylidene, the remainder being vinyl chloride, acrylonitrile, methyl methacrylate or methyl acrylate, and may be applied in solution in a 65/35 mixture of methyl ethyl ketone and toluene and subsequently dried. To assist adhesion the film and/or the paper may be pretreated with partially condensed urea- or melamine-formaldehyde resin or a mixture thereof, or with a polyethylene- or other -alkylene-imine. The regenerated cellulose film, after coating, may be reverse printed, and/or the paper printed, on the inner surface or surfaces and the reverse printing may be overprinted with a white or coloured background.
展开▼
