Patent GB-759102-A (GB)
Title: Improvements in or relating to dry release transfers and method of forming the same
IPC: B44C1/17
Filed: 1954-07-07
Abstract: 759,102. Transfers. MEYERCORD CO. July 7, 1954 [July 29, 1953], No. 19883/54. Drawings to Specification. Class 100 (2). In a dry strip transfer (strippable with or without heat) a temporary carrier with a dry release coating thereon carries an imprint comprising a number of superimposed layers one at least of which is in the form of a design, the layers each containing a resinous filmforming ingredient soluble in a solvent which would have no substantial effect on the resinous film-forming ingredient of the previously applied layer; in forming the transfer the imprint layers are applied as solutions in the appropriate solvents; the invention in particular enables gravure printing to be used for this purpose without the difficulty of one layer being lifted from the dry release coating during application of the next layer. An adhesive layer may be applied over the imprint; for this a heat-activatable adhesive may be used, in conjunction with wax for the dry-release coating, whereby on heating under pressure during the transfer operation, adherence to the surface to be decorated and release from the temporary carrier are simultaneously effected. In a heat-release transfer a glassine or other low-grade paper carrier coated with vegetable wax (m.p. 240‹ F.) carries an imprint comprising layers applied, in order, from the first and at least one other of the following solutions, the quantities being parts by weight: (a) cellulose acetate 16.7, methyl phthalyl ethyl glycollate 5.5, aryl sulphonamide formaldehyde amine resin 2.8, solvent 75; the solvent comprising acetone 81.8 per cent, methyl alcohol 9.1 per cent, methyl acetate 9.1 per cent; (b) nitrocellulose 8, plasticizer (one or more of: blown castor oil, dibutyl phthalate, tricresyl phosphate) 6, carbon black 4, solvent 82; the solvent comprising ethyl alcohol 5, ethyl acetate 30, butyl acetate 7, toluol 40; (c) ethyl cellulose 10, castor oil 5, solvent 85; the solvent comprising toluol 65, ethyl alcohol 20. Over this imprint an adhesive layer may be applied from a solution of (d) maleic modified resin 14, chrome yellow pigment (to form the background when the transfer is applied) 22, plasticizer (as in (b) above) 4, toluol 60. When (c) is omitted, there may be substituted for (d) one of the following: (e) polyvinyl methyl ether 10, chrome yellow pigment 20, ethyl alcohol 70; (f) acrylic ester resin 10, chrome yellow pigment 20, toluol 70. In another example, paper having a release coating of polymerized vinyl resin carries an imprint formed from (b) and (c) above, with an adhesive layer formed from (d), (e) or (f); in this case the adhesive layer may in use be solventactivated. A dry release coating of polyethylene or of dextrine or other gum may also be used. The imprint and adhesive layers may be applied by roll coating, brushing, spraying, knife spreading, screen printing, or gravure printing, apparatus for the latter process being described wherein a wax-coated glassine paper web is led through a number of rotary couples, after each of which it passes over a pair of internally-heated drying cylinders and then through an elongated heating zone.