WALLPAPER

1,142,875. Coated wallpaper. SCOTT BADER & CO. Ltd. 15 Feb., 1967 [23 June, 1966], No. 28213/66. Heading B2E, A wallpaper having a ground coat (which may have printing thereon) is treated by applying thereto an aqueous emulsion of a copolymer made essentially from (a) 30-80 parts by wt. of vinylidene chloride, and (b) 70-20 parts by wt. of alkyl acrylate and/or methacrylate having an alkyl chain length of 1-8 carbon atoms, which may in part be replaced by acrylonitrile and/or methacrylonitrile, to form a washable and strippable coating. The total amount of acrylonitrile and methacrylonitrile may be from 0-15 parts by wt. per 100 parts by wt. of (a) plus (b). The viscosity of the emulsion (55% solids, shear rate 12.62 secs-1 at 25‹C) may be 200-500 cps. The copolymer may contain, in additionto (a) plus (b), up to 10 parts by wt. acrylamide and/or methacrylamide per 100 parts by wt. of (a) plus (b) and may also contain a small amount of a copolymerisable acid such as acrylic or methacrylic acid. The coating may have a weight of at least 32 grams per sq. metre. The emulsion may be applied in two or more coatings, using the same emulsion at each stage or varying the emulsions. The coated wallpaper may be embossed. The ground coat may have a pigment:binder ratio between 6:1 and 14:1 by weight, and a coating weight higher than 20 grams per sq. metre. The binder of the ground coat may be starch, casein, or synthetic resin emulsion or solution, e.g. styrene-acrylic copolymers, polyvinyl alcohol and polyvinyl acetate. The emulsion may be applied using a roller coater followed by an air knife doctor.