Thermographic agglomerate of dyestuff precursor, developer, etc. - for use in thermographic material, allowing use of wide range of components

摘要

Thermographic compsn. consists of an agglomerate of a (nearly) colourless dyestuff precursor (I), a colour developer (II), which develops (I) on heating, and a sensitiser (III). It has an average dia. of 2-30 microns. The agglomerate is produced using a cationic dispersant (IV) and/or an alkali metal or ammonium salt (V) of a copolymer of maleic anhydride and a comonomer and/or by microencapsulation. A polymer pref. is incorporated in the microcapsules, pref. in the form of a microemulsion with an average emulsion dia. of 0.2 micron or less. This polymer pref. is water-soluble. USE/ADVANTAGE - The compsn. is useful in thermographic materials used in registering instruments, facsimile equipment, printers, computer terminals, labellers and automatic ticket machines. It has high sensitivity and allows the use of a wider range of (I), (II) and (III) than usual. (23pp Dwg.No.0/0)