| 摘要 |
1311862 Coated products WALLPAPER MFGS Ltd 24 Aug 1970 [19 Sept 1969] 46373/ 69 Addition to 1023468 Heading B2E [Also in Division D2] A dry-strippable wall covering comprises two laminae or lies of paper bonded together, the plies being produced on a long-wire or a twowire machine, the bottom ply being provided on the side for application to the wall with a wateractivatable adhesive coating and the tensile and cohesive strengths of the top ply not being less than those of the bottom ply so that the top ply is dry-strippable from the bottom ply. The plies may comprise only paper fibres or a blend of these with nylon, rayon or acrylic fibres. The top ply may consist of fully- or semi-bleached kraft pulp sized to Cobb value of 15-25 and the bottom ply may consist of 70% by weight ground wood pulp and 30% bleached sulphite pulp similarly sized. Both plies may be loaded with up to 15% china clay. The bonded plies may be produced as "twin furnished" paper preferably between the first and second suction boxes. The water-activatable adhesive may be methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, gum arabic, gum tragacanth, a soluble starch or starch ether, dextrin, alginate, animal glue, gelatin or a polymer such as polyvinyl alcohol, polyvinylmethyl ether, polyvinylpyrrolidone and vinyl acetate homopolymers and copolymers. It may be applied as an aqueous solution, dispersion or emulsion by roller coater or knife coater or as a powder after wetting of the surface with water or aqueous alginate or cellulosic solution. The top ply may be coated with a wear layer of plasticised PVC, vinyl acetate homopolymer or copolymer or a homo- or co-polymer of an acrylic or methacrylic monomer (e.g. vinyl acteate-butyl acrylate copolymer). A pattern may be printed or embossed either on the top ply or. on the wear layer. |
