Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J31/00—Ink ribbons; Renovating or testing ink ribbons
  • B41J31/05—Ink ribbons having coatings other than impression-material coatings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/382—Contact thermal transfer or sublimation processes
  • B41M5/38207—Contact thermal transfer or sublimation processes characterised by aspects not provided for in groups B41M5/385 - B41M5/395
  • B41M5/38214—Structural details, e.g. multilayer systems
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/382—Contact thermal transfer or sublimation processes
  • B41M5/392—Additives, other than colour forming substances, dyes or pigments, e.g. sensitisers, transfer promoting agents

Definitions

• the present invention relates to a multi-usable heat transfer ink ribbon used in a heat transfer type hard copy printer. More particularly, the invention relates to a heat transfer ink ribbon wherein the same portion of the ink layer can be used repeatedly for printing.
• Multi-usable heat transfer ink ribbons of this type which have been proposed heretofore include an ink ribbon wherein a nontransferable sponge-like resinous layer is impregnated with a heat transfer ink, an ink ribbon wherein a pigment having strong cohesive force is dispersed in a heat transfer ink to form a barrier like a stone wall against the migration of the ink by agglomeration of the pigment and the ink is flowed out in increments through the barrier, and an ink ribbon wherein porous particles are bonded to each other with a binder to form a porous layer and a heat transfer ink contained in the pores of the porous particles and the voids between the particles is flowed out in increments.
• the amount of the heat transfer ink which can be effectively used for printing is small as compared tc the thickness of the layer containing the heat transfer ink which has a strong dependence with the clearness of printed images, so that clear printed images cannot be obtained at every repeated use.
• the materials which must not be transferred are transferred by accident, which results in formation of printed images having unevenness in their optical density and formation of incomplete printed images involving defects such as voids and dropout portions at repeated use.
• the present invention provides a multi-usable heat transfer ink ribbon comprising a foundation, and a heat transfer ink layer provided on one surface of the foundation, said heat transfer ink layer having a melt index of 4 X 102 to 2.5 X 103 g/10 min. at 190°C and containing a vehicle and 3 X 10 to 6 X 10 % by volume of a nonthermoplastic powder dispersed in a nonagglomerative state, wherein said heat transfer ink layer is capable of being melted or softened to be transferred to a receiving medium in increments relative tc the thickness direction of the ink layer upon heating by means of a heating head.
• the melt index is measured according to the provision of ASTM ⁇ D1238.
• the ink layer is transferred in increments relative to the thickness direction thereof, thereby reducing the thickness of the ink layer little by little, at every time when the ink layer is heated by means of a heating head such as thermal head, and finally the whole ink layer of the ribbon is transferred and only the foundation remains in the ribbon.
• the mechanism of the transfer of the ink layer is presumed as follows: When the ink layer is heated by means of a heating head, there occur portions at which stress is centered, in the vicinity of the particles constituting the powder dispersed in a nonagglomerative state and, on the other hand, the ink layer is firmly bonded to the foundation due to the presence of the vehicle maintaining a high viscosity in a molten state. As a result, the part of the ink layer which is adjacent to a receiving medium is peeled at the intermediate of the ink layer thickness and transferred to the receiving medium. However, the reason why the thickness of a part of the ink layer transferred at every repeated use is stably almost constant is not unsolved.
• the melt index of the ink layer is 4 X 102 to 2.5 X 103 g/10 min. at 190°C and the content of the nonthermoplastic powder in the ink layer is 3 X 10 to 6 X 10 % by volume.
• melt index of the ink layer is increased, i.e. the ink layer is more softened, with increasing content of the powder.
• thermoplastic resin examples include rubber-­like resins including copolymers such as ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 40 % by weight and a melt index of 4 X 102 to 2 X 103 g/10 min at 190°C, ethylene-ethyl acrylate copolymer having an ethyl acrylate content of 10 to 40 % by weight having a melt index of 4 X 102 to 2 X 103 g/10 min.
• copolymers such as ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 40 % by weight and a melt index of 4 X 102 to 2 X 103 g/10 min at 190°C, ethylene-ethyl acrylate copolymer having an ethyl acrylate content of 10 to 40 % by weight having a melt index of 4 X 102 to 2 X 103 g/10 min.
• nonthermoplastic powder used herein means a powder which is not plasticized under the heating conditions for heat transfer. Any nonthermoplastic powder having such a particle size that it is not agglomerated when it is dispersed in the above-mentioned vehicle can be used.
• a powder having a particle size of not more than 1 X 102 ⁇ m is preferably used from the point of view of preventing the printed image from roughening of the surface thereof.
• nonthermoplastic powder examples include inorganic pigments having a particle size of 1 X 10 to 1 X 102 ⁇ m such as carbon black for use in coloring agent; body pigments such as diatomaceous earth, silica powder and calcium carbonate, and organic pigments.
• the nonthermoplastic powder also serves as a coloring agent.
• usual coloring agents such as pigments and dyes may be used together with the nonthermoplastic powder.
• additives such as dispersing agent for uniformly dispersing the powder into the ink vehicle, viscosity adjusting agent and surface property modifying agent may be added.
• Additives used for usual heat melt trasfer ink can be used as such additives.
• the viscosity adjusting agent are waxes such as paraffin wax, carnauba wax, montan wax, candelilla wax and ester wax.
• the surface property modifying agent for reducing the tackiness of the surface of the ink layer are amide waxes such as oleic amide, isostearic amide and N,N′-ethylenebis[oleic amide].
• examples of the dispersing agent are nonionic surface active agents.
• the ink layer is formed by solvent-coating the ink composition composed of the above-mentioned components on a foundation, followed by drying.
• the thickness of the ink layer is 5 to 30 ⁇ m.
• plastic films having a thickness of 1 to 20 um such as polyester film, polycarbonate film, polysulfone film, fluorine-containing resin film and polyimide film, papers having thickness of 5 to 50 ⁇ m, such as condenser paper, india paper and glassine paper, and cellophane having a thickness of 5 to 50 ⁇ m.
• M.I. melt index at 190°C.
• ethylene-vinyl acetate copolymer (M.I.: 1,200 g/10 min) as a main component of the vehicle, 14 parts of paraffin wax (mp: 65°C) as viscosity adjusting agent, 1 part of N,N′-ethylenebis[oleic amide] as a surface modifying agent, and 24 parts of carbon black (average particle size: 18 ⁇ m) and 14 parts of carbon black (average particle size: 56 ⁇ m) as a nonthermoplastic powder (which served also as a coloring agent) were dissolved or dispersed into a volatile solvent to give an ink coating liquid.
• paraffin wax mp: 65°C
• N,N′-ethylenebis[oleic amide] as a surface modifying agent
• carbon black average particle size: 18 ⁇ m
• 14 parts of carbon black average particle size: 56 ⁇ m
• the ink which was obtained by vaporizing the volatile solvent from the ink coating liquid had a M.I. of 1,200 g/10 min and a softening temperature (which means the temperature corresponding to the maximum peak in the differential scanning calorimetry curve) of 65°C.
• the ink coating liquid was applied to a polyethylene terephthalate film having a thickness of 4.5 ⁇ m so that the thickness of the resulting coating after being dried became 7 ⁇ m, and after evaporation of the solvent, cooled to an ordinary temperature to give a multi-usable heat transfer ink ribbon having a heat transfer ink layer.
• Example 2 The same procedures as in Example 1 except that the main component of the vehicle, the viscosity adjusting agent, the surface property modifier and the nonthermoplastic powder (serving also as a coloring agent) shown in Table 1 were used, were repeated to give heat transfer ink ribbons.
• the multi-usable heat transfer ink ribbon of the present invention though the whole of the ink layer is transferable by incorporating intc the ink layer no nontransferable material which hinders the transfer of the ink, can give printed images having the same clearness as that of the printed image obtained by the initial printing even after the ribbon is repeatedly used multiple times for printing.

Landscapes

• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Thermal Transfer Or Thermal Recording In General (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=16457228

Family Applications (1)

Country Status (4)

Cited By (5)

Citations (7)

Family Cites Families (4)

• 1988
  • 1988-08-12 JP JP63202421A patent/JPH0250887A/ja active Pending
• 1989
  • 1989-01-07 EP EP89100223A patent/EP0354293B1/fr not_active Expired - Lifetime
  • 1989-01-07 DE DE68924457T patent/DE68924457D1/de not_active Expired - Lifetime
  • 1989-01-10 KR KR1019890000198A patent/KR900002951A/ko not_active Application Discontinuation

Patent Citations (7)

Non-Patent Citations (5)

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