GB1412709A - Roller construction - Google Patents

Abstract

1412709 Coated roller CESKOSLOVENSKA AKADEMIE VED 19 Dec 1973 [22 Dec 1972] 58788/73 Heading B2E [Also in Division B6] A roller which is used for printing, dyeing or gilding on glass, or on other materials such as paper or plastics, consists of a cylindrical core of metal, plastics, hard rubber, ceramic or other material which does not swell in water and a jacket of an elastic hydrogel which contains a copolymer of arcylonitrile and a further monomer which may be acrylamide, methacrylamide either of which can be substituted, acrylic acid, methacrylic acid ethylenesulphonic acid or any of their salts, together with a swelling agent. Suitable swelling agents are water, alkylene or polyalkylene glycols or their methoxy or ethoxy derivatives wherein alkylene is C 2 -C 4 , glycerol or an acetyl derivative, phenol, aromatic or hydroaromatic alcohols, aliphatic C 1 -C 14 alcohols their esters or ethers, or fatty acids or their salts or esters. The roller is made by repeatedly applying solutions of the copolymer to the cylindrical core and then coagulating in a bath containing water and aliphatic alcohol (C 1 -C 4 ), acetone, dioxane, benzylalcohol, alkylene or polyalkylene glycols (alkylene C 2 -C 4 ), methoxy or ethoxy derivatives of alkylene glycols, glycerol or an acetyl derivative of glycerol; the swelling agent may be incorporated in the copolymer solution or in the coagulation bath; alternatively, the coated roller may be subsequently treated with the swelling agent. During or after coagulation, the copolymer may be crosslinked with cations Cr(III), Al(III), Fe(III), Cu(I), Ag(I) or with aldehydes or polyisocyanates. These agents may be applied to only part of the roller surface, as may non-cross-linking agents, such as mineral acids, aqueous solutions of alkylene hydroxides, nitrous acid, or trionyl chloride plus hydroazine, to influence various surface characteristics, e.g. hydrophilicity. Dimethylformamide, dimethylsulphonide or acrylic ethylene carbonate may be incorporated in the swelling agent. When not in use the roller is preferably stored in contact with a swelling agent.