Transfer elements and process for making same

Claim 1

A pressure-sensitive transfer element adapted to transfer solid, fluorescing images to a copy sheet under the effect of imaging pressure, comprising a smooth, thin plastic film foundation supporting a volatile solvent-applied, complete-transfer imaging layer comprising a synthetic thermoplastic resin binder material which is soluble in the application solvent, from about 0.25% to about 5.0% by weight, based upon the solids content, of a fluorescing dye in the form of a solid solution within said imaging layer and capable of emitting intense radiation within the range of from about 300 mμ to about 700 mμ when exposed to a light source rich in ultraviolet radiation, and a minor amount by weight of an opaque lamelliform pigment which is present mainly in a surface stratum of said imaging layer and is adapted to mask the color of the surface of said copy sheet to which said images are transferred without preventing said images from fluorescing under the effects of applied radiation.

Claim 10

A method for producing a pressure-sensitive transfer element adapted to transfer solid fluorescing images to a copy sheet under the effect of imaging pressure comprising the steps of: (a) preparing a coating composition by dissolving a synthetic thermoplastic resinous binder material and a fluorescing dye in a volatile organic solvent, said dye being capable of emitting intense radiation within the range of from about 300 mμ to about 700 mμ when exposed to a light source rich in ultraviolet radiation, and mixing therewith from about 0.25% to about 5.0% by weight, based upon the solids content of a lamelliform pigment; (b) applying said coating composition as a uniform thin layer to a smooth plastic film foundation, and (c) evaporating said volatile organic solvent to form a solid, complete-transfer imaging layer containing said fluorescing dye in the form of a solid solution and containing said lamelliform pigment mainly in a surface stratum as a masking agent which at least partially masks the color of the surface of the copy sheet to which said composition is transferred in image form without preventing the dye in said images from fluorescing under the effects of applied radiation.

Claim 11

A method for producing a pressure-sensitive transfer element adapted to transfer solid fluorescing images to a copy sheet under the effect of imaging pressure comprising the steps of: (a) preparing a coating composition by dissolving a synthetic thermoplastic resinous binder material and a fluorescing dye in a volatile organic solvent, said dye being capable of emitting intense radiation within the range of from about 300 mμ to about 700 mμ when exposed to a light source rich in ultraviolet radiation, and mixing therewith from about 0.25% to about 5.0% by weight, based upon the solids content of a lamelliform pigment; (b) applying said coating composition as a uniform thin layer to a smooth plastic film foundation, and (c) evaporating said volatile organic solvent to form a solid, complete-transfer imaging layer containing said fluorescing dye in the form of a solid solution and containing said lamelliform pigment mainly in a surface stratum as a masking agent which at least partially masks the color of the surface of the copy sheet to which said composition is transferred in image form without preventing the dye in said images from fluorescing under the effects of applied radiation.

Claim 17

A method according to any one of claims 9, 10, 13 or 14 in which said applied coating composition is maintained fluid for a sufficient time to permit a substantial portion of said lamelliform pigment to float towards the surface of the applied coating to form a surface stratum of concentrated lamelliform pigment adjacent said surface prior to the evaporation of the volatile organic solvent.