GB690623A - Improvements relating to transfers - Google Patents

Abstract

690,623. Transfers; transferring designs. BRITTAINS, Ltd. April 26, 1951 [May 8, 1950], No..11419/50. Class 100(ii) An improved transfer paper for use in printing with ceramic colours and fluxes for the decoration of heat-resisting bases, such as pottery, glass or vitreous enamels, comprises a decalcomania paper, such as a Duplex or Simplex paper, the gummed side of which is united by a water-soluble adhesive bond to a coating of a thermoplastic material which will accept a decoration printed with ceramic colours and fluxes and which becomes soft and adhesive at a tremperature of 50-100‹C and is volatilized or decomposed without residue below the maturing temperature of the decoration. The transfer paper is produced by coating the gummed side of Duplex or Simplex decalcomania paper with a solution of the thermoplastic material in an organic solvent such as toluene, acetone, methyl ethyl ketone, ethyl or butyl acetate. The coating should be at least as thick as the design printed on it, and should become adhesive at 50-100‹C. The thermoplastic material is preferably a polymeric synthetic resin such as polymethyl methaerylate, n-polybutyl methacrylate and polystyrene and their co-polymers, which depolymerize to the volatile monomer at temperatures below the maturing temperature of the decoration, and is compounded with volatile plasticizers, such as the chlorinated diphenyls and polyphenols known as Aroclors (the word " Aroclor " being a Registered Trade Mark), which evaporate at the same temperatures with little or no carbonization leaving no stain, or the phthalates, for example dibutyl phthalate. Alternatively, the material may be ethyl cellulose or nitrocellulose plasticized with "Aroclors " methyl abietate or phthalates and modified by the addition of suitable resins such as hydrogenated rosin, polyvinyl acetate, or, in the case of nitrocellulose, ester gum. Examples for use when dissolved in toluene for applying to Duplex paper are (a) 10 gms. polymethyl methacrylate, 15 gms. " Aroclor " 1254; (b) n-polybutyl methacrylate without a plasticizer; (c) 40 gms. polymethyl methacrylate, 20 c.c. dibutyl phthalate; (d) 20 gms. ethyl cellulose, 15 c.c. " Aroclor " 1254. Transferring designs.-The desired decoration is printed with ceramic colours and fluxes on to the thermoplastic coating previously applied to the paper, and the printed decoration cut out from the sheet leaving a suitable margin around the decoration. The decoration is applied to the surface to be decorated and heat-sealed to it, the paper is removed by the application of water, and the surface is heated to the maturing temperature of the colours and fluxes. The thermoplastic coating decomposes or volatilizes without residue during firing. If Duplex paper is used, the backing can be stripped from the tissue paper before applying the design, and the tissue paper and design applied to a surface pre-heated to a temperature at which the coating will adhere, or applied to a cold surface and moderate heat and pressure applied.