GB497335A - Improvements in or relating to the preparation of coated materials - Google Patents

Abstract

Resins prepared by condensing a non-aromatic amine, a phenol and an aldehyde, in any order, are used as an anchoring layer between a water-sensitive cellulosic base material and a coating material. The resins must be substantially insoluble in water and 5 per cent aqueous ammonia but must be soluble in 2 per cent acetic acid. The resins may be used in the form of aqueous solutions of their salts with acids such as acetic, formic citric, glycollic, malic, maleic, succinic, adipic, phthalic, tartaric, benzoic or hydrochloric acids. Glycerine may be added as a plasticizer. On drying the coating it becomes hard and insoluble. The cellulosic base materials include sheets of regenerated cellulose (which may be derived from viscose or cuprammonium cellulose), cellulose ethers (ethylcellulose, methylcellulose, glycolcellulose or cellulose glycollic acid) or cellulose esters (cellulose phthalate) tubes, sausage casings, bottle caps, bands or moulded articles or various cellulosic materials, rayon fabrics, paper or cotton cloth. The coating material to be anchored may be discontinuous such as printing on regenerated cellulose sheets, tubes, caps and sausage casings. The surface coating may be any coating composition containing a cellulose derivative base such as cellulose nitrate, cellulose acetate, ethyl cellulose, or benzyl cellulose or, preferably, a moisture proofing coating comprising a cellulose derivative, a wax or wax-like material, a blending agent and a plasticizer. In an example, regenerated cellulose sheet in the gel state prepared from viscose is coated with a composition prepared by dissolving a resin prepared from phenol or m-cresol, formaldehyde, dimethylamine and ammonia in a mixture of aqueous acetic acid and glycerine with or without the addition of de-acetylated chitin, the sheet is then dried and coated with a moisture-proofing composition comprising pyroxylin, gum dammar, dibutyl phthalate, paraffin wax, zinc stearate, ethyl stearate, toluene, alcohol and acetone. Specifications 282,435, [Class 2 (iii)], 283,109, [Class 95], 317,452, [Class 2 (ii)], and 458,814, are referred to.ALSO:Resins prepared by condensing a non-aromatic amine, a phenol and an aldehyde, in any order, are used as an anchoring layer between a water - sensitive cellulosic base material and a coating material. The resins must be substantially insoluble in water and 5 per cent aqueous ammonia but must be soluble in 2 per cent acetic acid. The resins may be used in the form of aqueous solutions of their salts with acids such as acetic, formic, citric, glycollic, malic, maleic, succinic, adipic, phthalic, tartaric, benzoic or hydrochloric acids. Glycerine may be added as a plasticizer. On drying the coating it becomes hard and insoluble. Preferably the phenolic body has at least two free reactive positions and only organic groups as ring constituents and the amine contains not more than six carbon atoms and at least one amino-nitrogen atom joined to a carbon atom which is not part of an aromatic ring and also to at least one hydrogen atom. The cellulosic base materials include sheets of regenerated cellulose (which may be derived from viscose or cuprammonium cellulose), cellulose ethers (ethylcellulose, methylcellulose, glycolcellulose or cellulose glycollic acid) or cellulose esters (cellulose phthalate) tubes, sausage casings, bottle caps, bands or moulded articles of various cellulosic materials, rayon fabrics, paper or cotton cloth. The coating material to be anchored may be discontinuous such as printing on regenerated cellulose sheets, tubes, caps and sausage casings. The surface coating may be any coating-composition containing a cellulose derivative base such as cellulose nitrate, cellulose acetate, ethyl cellulose, or benzyl cellulose or, preferably, a moistureproofing coating comprising a cellulose derivative, a wax or wax-like material, a blending agent and a plasticizer. In examples suitable resins are prepared from (a) phenol formaldehyde, dimethylamine and ammonia, (b) phenol, lignin, formaldehyde and dimethylamine, (c) phenol, formaldehyde and dimethylamine, (d) phenol, formaldehyde and dimethylaminoethanol, and (e) phenol, formaldehyde and cyclohexylamine. Other resins include those prepared from phenol, formaldehyde, and (2) lignin and methylamine, (3) cyclohexanolamine, (4) p-toluene sulphonamide and methylamine, (6) dimethylamine, and (9) ammonia and diethanolamine, from (1) xylenol, formaldehyde and methylamine, from (7) m-cresol, formaldehyde and dimethylamine, and from (8) xylenol, or (5) diphenylolcyclohexanone, formaldehyde and dimethylaminomethanol. In examples: (1) regenerated cellulose sheet in the gel state prepared from viscose is coated with a composition prepared by dissolving the resin from example (a) or a corresponding resin prepared from m-cresol instead of phenol in a mixture of aqueous acetic acid and glycerine, with or without the addition of de-acetylated chitin, the sheet is then dried and coated with a moistureproofing composition comprising pyroxylin, gum dammar, dibutyl phthalate, paraffin wax, zinc stearate, ethyl stearate, toluene, alcohol and acetone. Specifications 282,435, [Class 2 (iii)], 283,109, [Class 95], 317,452, [Class 2 (ii)], and 458,814 are referred to. A phenol-lignin condensate is prepared by heating phenol and spruce wood flour in the presence of hydrochloric acid.