THERMAL TRANSFER DYESHEETS

• Main Authors: DAVEY, ROGER JAMES, BLACK, SIMON NICHOLAS, MACKERRON, DUNCAN HENRY
• Format: Patent
• Language: English
• Published: 07.11.1990
• Edition: 5
• Subjects: COLOUR PRINTING; LINING MACHINES; PERFORMING OPERATIONS; PRINTING; PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; STAMPS; TRANSPORTING; TYPEWRITERS

A cleaner thermal transfer dyesheet comprises a supportive base material coated with a composition of a thermally transferable dye dispersed throughout a polymer matrix, the dye being composed of organic molecules alignable to form crystals having a major axis, and a molecular structure having at least one carbon atom bonded to a single moiety and positioned in the molecule such that the size of said moiety affects the rate of crystal growth along the major axis; the coating having in addition to the dye molecules, a minor amount of a crystallisation modifier consisting of molecules essentially the same as the dye molecules except that said moiety is replaced by a more bulky substituent. Likewise, where the dye is recognised as having a molecular structure with one or more carbon atoms each bonded to a single moiety positioned to extend from the prime face, a crystallisation modifier consists of molecules essentially the same as the dye molecules except that said moiety is replaced by a more bulky substituent. The effect of adding a minor amount of such crystallisation modifie is to provide a cleaner, more stable dyesheet.