Patent GB-973362-A (GB)
Title: Transfer sheets
Inventor: POPIOLEK WLADISLAS
IPC: B41M5/04
Filed: 1961-05-16
Abstract: A coating composition, for use in making hectographic transfer sheets (see Division D2), comprises a dye or dye-forming compound, a substantially waxless liquid or semi-solid resinous material and a finely divided material which serves to convert the liquid or semi-solid resinous material into a non-tacky state, and may be dissolved in a solvent (trichlorethylene in each of the following examples).  In the examples, compositions comprise: (1, 2 and 4) a copolymer of vinyl ether and isobutylene, a modified ureaformaldehyde resin, methyl violet and carbon black; (5) modified ester gum, modified ureaformaldehyde resin, methyl violet, and carbon black; (6 and 7) cyclized rubber or chlorinated rubber respectively, with dioctyl sebacate, methyl violet, and carbon black; (10) leuco ethyl violet, polyvinyl acetate, dibutyl phthalate, colophony, mineral oil, long-chain fatty amine and mica; (11) copolymer of vinyl ether and isobutylene, methyl violet and carbon black; (12) copolymer of ethylene and vinyl acetate, dibutyl phthalate, burnt shale, carbon black and methyl violet; (13) polyvinyl acetate, methyl violet, dibutyl phthalate and burnt shale; (14) as 13 but with part of the dibutyl phthalate replaced by castor oil; and (15) as 13 but with reduced proportions of dibutyl phthalate and burnt shale, and with the addition of carbon black, aluminium powder and an N-alkyl-trimethylene-diamine. Specification 795,869 is referred to.ALSO:Compositions for coating on to base sheets of paper, plastics film or regenerated cellulose, to make hectographic transfer sheets (see Division D2), may comprise colophony, mineral oil, a dye or dye-forming compound, a finely-divided solid material and trichlorethylene as solvent.  Dyes and dye-formers referred to are Methyl Violet 10 BNS, diazodiethylaniline and nigrosine base. Solid materials are titan white, carbon black and mica. Specification 795,869 is referred to.ALSO:A hectographic transfer sheet comprises (1) a base sheet, (2) a layer of a substantially waxless hectographic transfer composition superposed on the base sheet, which composition comprises a dye or dye-forming compound, a substantially waxless liquid or semi-solid resinous material, and a finely divided material which serves to convert the liquid or semi-solid resinous material into a non-tacky state, and (3) a frangible supercoating.  When a master sheet for a hectographic process is superposed on the coated side of the transfer sheet and pressure is applied to form an image, substantially complete transfer of the transfer composition and super-coating occurs from the area to which pressure is applied. The base sheet may be of paper, plastics film or regenerated cellulose. The resinous materials may be liquid or semi-solid of themselves or may be made so by means of plasticizers.  Examples of resinous materials are resin, modified ester gums, copolymers of vinyl ether and isobutylene, polyvinyl acetate, cyclized rubber, chlorinated rubber, urea-formaldehyde resin, copolymer of ethylene and vinyl acetate phenolic and modified phenolic resins, or maleic resins.  The finely divided material may be china clay, burnt shale, aluminium powder, titanium dioxide or carbon black. It may comprise lamellar particles, e.g. mica.  Dyes and dye-forming substances referred to are: Methyl Violet, diazo-diethyl-aniline, nigrosine base and Leuco Ethyl Violet.  The composition may also include a surface-active agent, or a non-volatile non-plasticizing oil, e.g. mineral oil.  The super-coating may be of wax e.g. beeswax or paraffin wax with or without a resin or chlorinated rubber.  It may also include a finely divided filler or pigment.  The sheet may be made by applying to a base sheet a solution or suspension of the transfer composition in a volatile solvent, evaporating the solvent and applying a coating of wax at a high temperature or in solution to form the frangible super-coating.  Specification 795,869 is referred to.