GB1014392A - Improvements in or relating to copy paper - Google Patents

Abstract

A composition, used to make an acceptor layer for copy sheets (see Division D2), comprises rosin, titanium dioxide, dioctyl sebacate and alcohol.ALSO:A donor layer for a copy sheet (see Division D2] comprises a binding agent, an internal or external plasticizer therefor, an inorganic filler and an organic fixative which is an aromatic carboxylic acid, an aromatic hydroxy compound, a substituted aromatic hydroxy compound or a derivative thereof, and may be applied in solution or dispersion. In the examples, compositions comprise: (1) polyvinyl acetate, gallic acid, alcohol and a paste of carbon black, dibutyl phthalate, castor oil, calcium sulphate, zinc oxide, ethylene glycol monomethyl ether, and butyl alcohol; (2) copolymer of vinyl chloride and methyl acrylate, tannin, ethyl acetate, alcohol, and a paste of carbon black, titanium dioxide, dioctyl sebacate, calcium sulphate, ethylene glycol monomethyl ether and butyl alcohol; (3) phenol-coumarone resin, 5-chloro-2-hydroxy-benzophenone, alcohol and a paste of Berlin blue, kaolin, dioctyl sebacate and castor oil; (4) polychloroprene, phenyl salicylate, trichlorethylene, and a paste of carbon black, castor oil, ricinoleic acid, calcium sulphate, tricalcium phosphate and ethylene glycol monomethyl ether; (5) polycarbonate, 2:4-dibenzoylresorcinol, methylene chloride, and the same paste as in Example (4); (6) copolymer of styrene and butadiene, salicylic acid, trichlorethylene and the same paste as in Example (2); (7) polyvinyl acetate, benzoic acid, trichlorethylene and the same paste as in Example (3); (8) copolymer of vinyl acetate and vinyl chloride, phenol, methyl ethyl ketone and the same paste as in Example (1); and (16)-(24) a solution as described below for each example separately and a paste of carbon black, kaolin, titanium dioxide, ethylene glycol monomethyl ether, castor oil and dibutyl phthalate. The solutions of Examples (16)-(24) comprise: (16) ethylcellulose, tannic acid, trichlorethylene and ethyl alcohol; (17) nitrocellulose, tannic acid and ethyl acetate; (18) cellulose acetate, phthalic acid and ethyl acetate; (19) cellulose propionate, phthalic acid and methylene chloride; (20) cellulose butyrate, phthalic acid and methylene chloride; (21) cellulose acetopropionate, phthalic acid and methylene chloride; (22) cellulose acetobutyrate, phthalic acid and methylene chloride; (23) benzylcellulose, phthalic acid and methylene chloride; and (24) methylcellulose, tannic acid, water and ethyl alcohol. A composition for a protective layer comprises (Example 28) a vinyl acetate polymer, alcohol, tannic acid and a paste of titanium dioxide, ethylene glycol monomethyl ether, castor oil and dioctyl phthalate.ALSO:A copy paper comprises a carrier sheet having on one face a donor layer comprising a binding agent, internal or external plasticizer therefor, an inorganic filler and an organic fixative which is an aromatic carboxylic acid, an aromatic hydroxy compound, a substituted aromatic hydroxy compound or a derivative thereof. This fixative enables the donor layer to have a microscopically discrete character so that when substantial local pressure is applied to the other face of the sheet, the donor layer will transfer locally in bodily form to an acceptor layer comprising a binding agent and a plasticizer therefor, but not to untreated paper. A carrier sheet may have a donor coating on one face, and no coating on the other; such a sheet can be used only as an original or top sheet in a set of copy papers. A sheet may have an acceptor layer on one face, and no coating on the other; such a sheet can be used only as a bottom sheet in a set. A sheet may have an acceptor layer on one face and a donor layer on the other; such a sheet can be used as an original, as a bottom sheet, or as an intermediate sheet in a set. The acceptor layer can be written upon with a pen, pencil or typewriter. A sheet can also have both donor and acceptor layers on the same side, and be used as a normal carbon paper. The donor layer may have superimposed on it a protective layer of composition similar to that of the donor layer but containing a white pigment and no coloured pigment. The preferred fixative is tannic acid, but the Specification lists many others. The acceptor layer may also contain a white pigment, e.g. titanium dioxide, zinc oxide or lithopone. The binder in the donor and acceptor layers may be polyvinyl acetate, a copolymer of vinyl chloride, a copolymer of vinyl chloride and methyl acrylate, polymethyl acrylate or methacrylate, a polycarbonate, polystyrene, polychloroprene, a copolymer of styrene and butadiene, polyethylene, a polydiolefine, a cellulose ester or ether, a cellulose ester containing carboxyl groups, resin, coumarone resin, a coumarone-phenol resin, or a maleic acid-modified abietic acid. The placticizer may be any of the usual esters of which a list is given and may be used with a material that softens the donor layer without dissolving the binder, e.g. castor oil or ricinoleic acid. When polyethylene is used for the acceptor layer, it may be plasticized with paraffin wax, stearic acid, a long-chain fatty alcohol or an ester or amide of an oil or wax. The pigment in the donor layer may be carbon black or milori blue. The inorganic filler, which must be used in addition to the pigment may be bentonite, calcium carbonate calcium sulphate, kaolin or titanium dioxide. The carrier sheet may be a paper made opaque by loading with titanium white, zinc white or barytes, or may be a foil of polyethylene or polyester.