Patent GB-1111831-A (GB)
Title: Copying paper and a method of making copies using the copying paper
IPC: B41M5/10
Filed: 1965-04-23
Abstract: Compositions for making a covering layer in a pressure-sensitive record sheet (see Division D2) comprise: (Formulation 1) vinyl chloride-vinyl acetate copolymer, acrylic resin, chlorinated rubber, dibutyl phthalate, castor oil, titanium white, calcium carbonate, methyl ethyl ketone, ethyl acetate and toluene; (Formulation 2) vinyl chloride-vinyl acetate copolymer, acrylic resin, dibutyl phthalate, castor oil, titanium white, barium sulphate, methyl ethyl ketone, ethyl acetate and toluene; (Formulation 3) vinyl chloride-vinyl acetate copolymer, ethylcellulose, dibutyl phthalate, polymerized castor oil, prussian blue, titanium white, calcium carbonate, methyl isobutyl ketone, ethyl acetate and toluene; (Formulation 4) cellulose acetate butyrate, chlorinated rubber, dioctyl phthalate, mineral oil, titanium white, calcium carbonate, methyl ethyl ketone and toluene; (Formulation 5) nitrocellulose, polyvinyl butyral castor oil, glycerine, lithol red, titanium white and methanol; (Formulation 6) polyvinyl chloride, dibutyl phthalate, kerosene, stearic acid, titanium white, gypsum, polyoxyethylene alkyl ether and water. Compositions for an adhesive layer in the record sheet comprises: (Formulation 6) vinyl chloride - vinyl acetate copolymer, dioctyl phthalate, methyl ethyl ketone and toluene; (Formulation 7) chlorinated rubber, castor oil, toluene and titanium white.ALSO:A composition for making a covering layer in a pressure-sensitive record sheet (see Division D2) comprises: (Formulation 7) gelatine, kerosene, stearic acid, potassium oleate, titanium white, gypsum and water.  Compositions for an adhesive layer in the record sheet comprise: (Formulation 1) micro-wax and titanium white; (Formulation 2) paraffin wax and calcium stearate; (Formulation 3) paraffin wax, polyethylene and titanium white; and (Formulation 4) paraffin wax and rosin.ALSO:A copying sheet, suitable for use in a composite stack of sheets, comprises a base layer, a dark-coloured layer on one side of the base layer, an exfoliatable covering layer of light colour adjacent to the dark-coloured layer, a layer of synthetic resin, polymer or protein on the opposite side of the base layer, and a layer of pressure-sensitive adhesive adjacent to the layer of synthetic resin, polymer or protein.  Such sheets may be stacked so that the covering layer of each sheet other than the top sheet faces the adhesive layer of the next sheet.  Alternatively the top sheet of the stack may comprise only a base layer, a layer of synthetic resin, polymer or protein, and an adhesive layer, the bottom sheet may comprise only a covering layer, a dark-coloured layer and a base layer, and the intermediate sheets comprise all the layers above. When pressure is exerted on such a stack, as by writing or typing, from the direction towards which the covering layers are facing, the part of each covering layer that is pressed is exfoliated from the adjacent dark-coloured layer, and sticks to the adhesive layer of the next sheet.  Two embodiments are described; in the first (Figs. 1-4, not shown) a dark-coloured paper serves as base layer and as dark-coloured layer; in the second (Figs. 5-8 not shown) the dark-coloured layer is a separate layer, e.g. of printers ink, applied to the base layer.  In both, the covering layer is a film comprising a main film-forming component a secondary film-forming component, pigment and a substance that is immiscible with the main film-forming component and is a fatty oil, a hydrogenated oil, a fat, a wax, polymerized castor oil, a fatty acid, a fatty alcohol, a polyhydric alcohol, a polyethylene glycol, a metallic soap, a mineral oil or petrolatum.  It is coated on the coloured face as a solution or emulsion.  In the Examples:  Compositions for the covering layer comprise: (Formulation 1) vinyl chloride-vinyl acetate copolymer, acrylic resin, chlorinated rubber, dibutyl phthalate, castor oil, titanium white, calcium carbonate, methyl ethyl ketone, ethyl acetate and toluene; (Formulation 2) vinyl chloride-vinyl acetate copolymer, acrylic resin, dibutyl phthalate, castor oil, titanium white, borium sulphate, methyl ethyl ketone, ethyl acetate and toluene; (Formulation 3) vinyl chloride-vinyl acetate copolymer, ethylcellulose, dibutyl phthalate, polymerized castor oil, prussian blue, titanium white, calcium carbonate, methyl isobutyl keytone, ethyl acetate and toluene; (Formulation 4) cellulose acetate butyrate, chlorinated rubber, dioctyl phthalate, mineral oil, titanium white, calcium carbonate, methyl ethyl ketone and toluene; (Formulation 5) nitrocellulose, polyvinyl butyral, caster oil, glycerine, lithol red, titanium white and methanol; (Formulation 6) polyvinyl chloride, dibutyl phthalate, kerosene, stearic acid, titanium white, gypsum, polyoxyethylene alkyl ether and water; (Formulation 7) gelatine, keroxene, stearic acid, potassium oleate, titanium white, gypsum and water.  Compositions for the adhesive layer comprise: (Formulation 1) microwax and titanium white; (Formulation 2) paraffin wax and calcium stearate; (Formulation 3) paraffin wax, polyethylene and titanium white; (Formulation 4) paraffin wax and rosin; and (Formulation 6) vinyl chloride-vinyl acetate copolymer, dioctyl phthalate, methyl ethyl ketone and toluene.  The layer of synthetic resin, polymer or protein may be coated on to the dark-coloured paper as a solution or emulsion, e.g. of carboxymethylcellulose in water, nitrocellulose in methyl ethyl ketone and toluene, polyvinyl chloride in methyl ethyl ketone and toluene or gelatin and casein in an alkaline solution.  The adhesive layer may be a wax with one or more of the following: pigment, calcium stearate, polyethylene or rosin, and applied melted; or nitrocellulose and rosin applied from solution in methanol; or a copolymer of vinyl chloride and vinyl acetate plasticized with dioctyl phthalate and applied from solution in methyl ethyl keytone and toluene; or chlorinated rubber plasticized with castor oil, pigmented with titanium white and applied from solution in toluene. The adhesive layer is preferably of the same colour as the covering layer. p