EP0663301A1 - Matériau d'enregistrement pour un procédé direct de formation d'images thermiques - Google Patents

Matériau d'enregistrement pour un procédé direct de formation d'images thermiques Download PDF

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Publication number
EP0663301A1
EP0663301A1 EP94203655A EP94203655A EP0663301A1 EP 0663301 A1 EP0663301 A1 EP 0663301A1 EP 94203655 A EP94203655 A EP 94203655A EP 94203655 A EP94203655 A EP 94203655A EP 0663301 A1 EP0663301 A1 EP 0663301A1
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EP
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Prior art keywords
recording material
heat
material according
layer
spacer layer
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EP94203655A
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German (de)
English (en)
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EP0663301B1 (fr
Inventor
Carlo Agfa-Gevaert N.V. Die 3800 Uyttendaele
Roland Agfa-Gevaert N.V. Die 3800 Beels
Luc Agfa-Gevaert N.V. Die 3800 Leenders
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Agfa Gevaert NV
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Agfa Gevaert NV
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
    • G03C1/00—Photosensitive materials
    • G03C1/494—Silver salt compositions other than silver halide emulsions; Photothermographic systems ; Thermographic systems using noble metal compounds
    • G03C1/498—Photothermographic systems, e.g. dry silver
    • G03C1/4989—Photothermographic systems, e.g. dry silver characterised by a thermal imaging step, with or without exposure to light, e.g. with a thermal head, using a laser
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
    • G03C1/00—Photosensitive materials
    • G03C1/494—Silver salt compositions other than silver halide emulsions; Photothermographic systems ; Thermographic systems using noble metal compounds
    • G03C1/498—Photothermographic systems, e.g. dry silver
    • G03C1/49872—Aspects relating to non-photosensitive layers, e.g. intermediate protective layers

Definitions

  • the present invention relates to a recording material suited for use in direct thermal imaging.
  • Thermal imaging or thermography is a recording process wherein images are generated by the use of imagewise modulated thermal energy.
  • thermography two approaches are known:
  • Thermal dye transfer printing is a recording method wherein a dye-donor element is used that is provided with a dye layer wherefrom dyed portions or incorporated dye is transferred onto a contacting receiver element by the application of heat in a pattern normally controlled by electronic information signals.
  • Thermography is concerned with materials which are substantially not photosensitive, but are sensitive to heat or thermosensitive. Imagewise applied heat is sufficient to bring about a visible change in a thermosensitive imaging material.
  • thermographic recording materials are of the chemical type. On heating to a certain conversion temperature, an irreversible chemical reaction takes place and a coloured image is produced.
  • a typical heat-sensitive copy paper includes in the heat-sensitive layer a thermoplastic binder, e.g ethyl cellulose, a water-insoluble silver salt, e.g. silver stearate and an appropriate organic reducing agent, of which 4-methoxy-1-hydroxy-dihydronaphthalene is a representative.
  • a thermoplastic binder e.g ethyl cellulose
  • a water-insoluble silver salt e.g. silver stearate
  • an appropriate organic reducing agent of which 4-methoxy-1-hydroxy-dihydronaphthalene is a representative.
  • a heterocyclic organic toning agent such as phthalazinone is added to the composition of the heat-sensitive layer.
  • Thermo-sensitive copying paper is used in "front-printing” or “back-printing” using infra-red radiation absorbed and transformed into heat in contacting infra-red light absorbing image areas of an original as illustrated in Figures 1 and 2 of US-P 3,074,809.
  • thermal printing image signals are converted into electric pulses and then through a driver circuit selectively transferred to a thermal printhead.
  • the thermal printhead consists of microscopic heat resistor elements, which convert the electrical energy into heat via Joule effect.
  • the electric pulses thus converted into thermal signals manifest themselves as heat transferred to the surface of the thermal paper wherein the chemical reaction resulting in colour development takes place.
  • a recording material is used in the form of an electrically resistive ribbon having e.g. a multilayered structure in which a carbon-loaded polycarbonate is coated with a thin aluminium film (ref. Progress in Basic Principles of Imaging Systems - Proceedings of the International Congress of Photographic Science GmbH (Cologne), 1986 ed. by Friedrich Granzer and Erik Moisar - Friedr. Vieweg & Sohn - Braunschweig/Wiesbaden, Figure 6. p. 622).
  • Current is injected into the resistive ribbon by electrically addressing a print head electrode contacting the carbon-loaded substrate, thus resulting in highly localized heating of the ribbon beneath the energized electrode.
  • the aluminium film makes direct contact with the heat-sensitive recording layer or its protective outermost layer.
  • the image signals for modulating the electrode current are obtained directly e.g. from opto-electronic scanning devices or from an intermediary storage means, e.g. magnetic disc or tape or optical disc storage medium, optionally linked to a digital image work station wherein the image information can be processed to satisfy particular needs.
  • an intermediary storage means e.g. magnetic disc or tape or optical disc storage medium
  • Heat-sensitive copying papers including a recording layer having a substantially light-insensitive organic silver salt and a hydroxylamine type reductor in a thermoplastic binder such as ethyl cellulose and after-chlorinated polyvinyl chloride are described in US-P 4,082,901. When used in thermographic recording operating with thermal printheads said copying papers will not be suited for reproducing images with fairly large number of grey levels as is required for continuous tone reproduction.
  • the operating temperature of common thermal printheads is in the range of 300 to 400 °C as can be learned from the above mentioned "Handbook of Imaging Materials", p. 502) and the heating time per heating element (picture element) may be less than 1.0 ms, the pressure contact of the thermal printhead with the recording material being e.g. 200-500 g/cm2 to ensure a good transfer of heat.
  • a non-photosensitive heat-sensitive recording material suited for use in direct thermal imaging by means of information-wise energized heating elements, wherein said recording material comprises :
  • the present invention includes likewise the use of said recording material in direct thermal imaging.
  • thermographic recording method wherein said heat-sensitive recording material is image-wise heated by means of a thermal head containing a plurality of image-wise electrically energized heating elements, and said heat-attenuating layer results in a reduction of gradation, i.e. an increase of the number of gray levels, of images obtained by said heating.
  • thermo working relationship means here that said substantially light-insensitive metal salt and said reducing agent by means of heat can react to form the metal itself.
  • said ingredients (1) and (2) may be present in a same layer or different layers wherefrom by heat they can come into reactive contact with each other, e.g. by diffusion or mixing in the melt.
  • grade refers to the slope of a characteristic curve representing the relationship of optical density (D) plotted in the ordinate versus linearly increasing amounts of heat plotted in the abscissa, said different amounts of heat being applied to the thermographic material in neighbouring area analogously to the production of a stepwedge.
  • D optical density
  • the linear increase of heat is obtained e.g. by linearly increasing the heating time at different areas of the recording material while keeping the heat input (J) per time unit (s) constant; alternatively the heating time can be kept constant and the amount of input-heat is increased linearly.
  • ⁇ is the maximum gradient of said characteristic curve, which is normally the gradient between the end of the toe and the beginning of the shoulder of the characteristic curve.
  • ⁇ is the most important gradient determining the gray scale or the range of image tone reproduction.
  • At least one spacer layer acting to some extent as a heat-insulating layer between neighbouring heat-sensitive imaging layers makes that the imaging layer more remote from the heating element(s) receive(s) less heat whereby the optical density in correspondence with the total heating range will be better differentiated giving rise to a larger amount of visually recognizable "gray-levels" in the final print.
  • the spacer layer(s) functioning as heat-attenuating layer(s) are preferably made of a film-forming transparent hydrophobic resin or polymer.
  • Particularly suitable polymers for that purpose are polyesters and polycarbonates.
  • the thickness of the spacer layer(s) depends on their heat-insulating power which corresponds with a poor thermal conductivity, but for preventing a too strong reduction in sensitivity the thickness of one spacer layer or a group of spacer layers is preferably in the range of 5 to 30 ⁇ m.
  • heat-attenuating spacer layers are applied by coating a resin solution or dispersion, the latter being called a latex, and removing its liquid carrier by drying.
  • Said liquid carrier is selected preferably in such a way that it is not a solvent for the binder in the underlying heat-sensitive imaging layer. Operating that way it is the intention not to disturb the image-forming characteristics of the heat-sensitive layer.
  • the ingredients of the heat-sensitive layer containing polyvinyl butyral as binder are coated from a solution in which methyl ethyl ketone is the solvent and the resin of the heat-attenuating layer is coated from a rubber latex wherein water is the liquid medium being not a solvent for polyvinyl butyral.
  • heat-attenuating spacer layers are applied by lamination either or not using a glue or adhesive sticking layer.
  • Suitable heat-attenuating spacer layers that can be applied by lamination are polyethylene terephthalate or Bisphenol A-polycarbonate strata that are laminated by means of a pressure-sensitive adhesive layer to an underlying heat-sensitive layer, e.g. using a pressure-sensitive adhesive as described in US-P 5,147,490.
  • a gradation-lowering effect is also obtained by including in the spacer layer(s) finely divided (colloidal) optically transparent inert pigments having heat-insulating power, such as transparent colloidal silica not masking the formed metal pattern.
  • the metal salt used in the recording material of the present invention is a substantially light-insensitive organic silver salt.
  • Substantially light-insensitive organic silver salts particularly suited for use in recording materials according to the present invention are silver salts of aliphatic carboxylic acids known as fatty acids, wherein the aliphatic carbon chain has preferably at least 12 C-atoms, e.g. silver laurate, silver palmitate, silver stearate, silver hydroxystearate, silver oleate and silver behenate, and likewise silver dodecyl sulphonate described in US-P 4,504,575 and silver di-(2-ethylhexyl)-sulfosuccinate described in published European patent application 227 141.
  • Useful modified aliphatic carboxylic acids with thioether group are described e.g.
  • Suitable organic reducing agents for the reduction of metal salts are organic compounds containing at least one active hydrogen atom linked to O, N or C, such as is the case in aromatic di- and tri-hydroxy compounds, e.g. hydroquinone and substituted hydroquinones, catechol, pyrogallol, gallic acid and gallates; aminophenols, METOL (tradename), p-phenylenediamines, alkoxynaphthols, e.g. 4-methoxy-1-naphthol described in US-P 3,094,417, pyrazolidin-3-one type reducing agents, e.g.
  • PHENIDONE (tradename), pyrazolin-5-ones, indanedione-1,3 derivatives, hydroxytetrone acids, hydroxytetronimides, hydroxylamine derivatives (ref. e.g. US-P 4,082,901), hydrazine derivatives, reductones, and ascorbic acid; see also US-P 3,074,809, 3,080,254, 3,094,417 and 3,887,378.
  • catechol and polyhydroxy spiro-bis-indane compounds corresponding to the following general formula: wherein R10 represents hydrogen or alkyl, e.g. methyl or ethyl, each of R11 and R12 (same or different) represents H, an alkyl group, e.g. methyl, ethyl or propyl, an alkenyl group or a cycloalkyl group, e.g. cyclohexyl group, or R11 and R12 together represent the atoms necessary to close a homocyclic non-aromatic ring, e.g.
  • each of R13 and R14 represents H, an alkyl group, e.g. methyl, ethyl or propyl, an alkenyl group or a cycloalkyl group, e.g. cyclohexyl group, or R13 and R14 together represent the atoms necessary to close a homocyclic non-aromatic ring, e.g. cyclohexyl, each of Z1 and Z2 (same or different) represents the atoms necessary to close an aromatic ring or ring system, e.g. benzene ring, substituted with at least two hydroxyl groups in ortho- or para-position and optionally further substituted with at least one hydrocarbon group, e.g an alkyl or aryl group.
  • R13 and R14 represents H, an alkyl group, e.g. methyl, ethyl or propyl, an alkenyl group or a cycloalkyl group, e.g. cyclohe
  • polyhydroxy-spiro-bis-indane compounds described in US-P 3,440,049 as photographic tanning agent more especially 3,3,3',3'-tetramethyl-5,6,5',6'-tetrahydroxy-1,1'-spiro-bis-indane (called indane I) and 3,3,3',3'-tetramethyl-4,6,7,4',6',7'-hexahydroxy-1,1'-spiro-bis-indane (called indane II).
  • Indane is also known under the name hydrindene.
  • the reducing agent is added to the heat-sensitive imaging layer but as already mentioned all or part of the reducing agent may be added to an adjacent layer wherefrom it can diffuse into the layer containing the substantially light-insensitive silver salt.
  • the present heat-sensitive recording material may contain one or more primary reducing agents of the type defined above in combination with one or more auxiliary reducing agents having poor reducing power compared with said main reducing agents.
  • the auxiliary reducing agents are incorporated preferably in the heat-sensitive layer containing the organic silver salt. For that purpose sterically hindered phenols and aromatic sulphonamide compounds are useful.
  • Sterically hindered phenols as described e.g. in US-P 4,001,026 are examples of such auxiliary reducing agents that can be used in admixture with said organic silver salts without premature reduction reaction and fog-formation at room temperature.
  • the silver image density depends on the coverage of the above defined reducing agent(s) and organic silver salt(s) and has to be preferably such that on heating above 100 °C an optical density of at least 1.5 can be obtained.
  • the reducible silver salt(s) and reducing agents are advantageously used in conjunction with a so-called toning agent known from thermography or photo-thermography.
  • Suitable toning agents are the phthalimides and phthalazinones within the scope of the general formulae described in US-P 4,082,901. Further reference is made to the toning agents described in US-P 3,074,809, 3,446,648 and 3,844,797. Particularly useful toning agents are likewise the heterocyclic toner compounds of the benzoxazine dione or naphthoxazine dione type.
  • a toner compound particularly suited for use in combination with said polyhydroxy spiro-bis-indane reducing agents is 3,4-dihydro-2,4-dioxo-1,3,2H-benzoxazine described in US-P 3,951,660.
  • thermoplastic water-insoluble resins are used wherein the ingredients can be dispersed homogeneously or form therewith a solid-state solution.
  • thermoplastic water-insoluble resins are used wherein the ingredients can be dispersed homogeneously or form therewith a solid-state solution.
  • all kinds of natural, modified natural or synthetic resins may be used, e.g.
  • cellulose derivatives such as ethylcellulose, cellulose esters, carboxymethylcellulose, starch ethers, polymers derived from ⁇ , ⁇ -ethylenically unsaturated compounds such as polyvinyl chloride, after-chlorinated polyvinyl chloride, copolymers of vinyl chloride and vinylidene chloride, copolymers of vinyl chloride and vinyl acetate, polyvinyl acetate and partially hydrolyzed polyvinyl acetate, polyvinyl alcohol, polyvinyl acetals, e.g.
  • polyvinyl butyral copolymers of acrylonitrile and acrylamide, polyacrylic acid esters, polymethacrylic acid esters, polystyrene and polyethylene or mixtures thereof.
  • a particularly suitable ecologically interesting (halogen-free) binder is polyvinyl butyral.
  • a polyvinyl butyral containing some vinyl alcohol units is marketed under the trade name BUTVAR B79 of Monsanto USA.
  • the binder to organic silver salt weight ratio is preferably in the range of 0.2 to 6, and the total thickness of all the heat-sensitive imaging layers present in the thermosensitive recording material according to the present invention should preferably be in the range of 5 to 16 ⁇ m.
  • the layer containing the organic silver salt is commonly coated on a support in sheet- or web-form from an organic solvent containing the binder dissolved therein but may be applied from an aqueous medium as a latex, i.e. as aqueous polymer dispersion.
  • aqueous polymer dispersion i.e. as aqueous polymer dispersion.
  • the dispersable polymer has preferably some hydrophilic functionality.
  • Polymers with hydrophilic functionality for forming an aqueous polymer dispersion (latex) are described e.g. in US-P 5,006,451, but serve therein for forming a barrier layer preventing unwanted diffusion of vanadium pentoxide present as antistatic agent.
  • the heat-sensitive layer containing the organic substantially light-insensitive silver salt and optionally an adjacent layer containing a reducing agent may contain waxes or "heat solvents” also called “thermal solvents” or “thermosolvents” improving the reaction speed of the redox-reaction at elevated temperature.
  • heat solvent in this invention is meant a non-hydrolyzable organic material which is in solid state in the recording layer at temperatures below 50 °C but becomes a plasticizer for the recording layer in the heated region and/or liquid solvent for the reducing agent combined with the organic silver salt, at a temperature above 60 °C.
  • heat solvent a non-hydrolyzable organic material which is in solid state in the recording layer at temperatures below 50 °C but becomes a plasticizer for the recording layer in the heated region and/or liquid solvent for the reducing agent combined with the organic silver salt, at a temperature above 60 °C.
  • a polyethylene glycol having a mean molecular weight in the range of 1,500 to 20,000 described in US-P 3,347,675.
  • the heat-sensitive layers may contain other additives such as free fatty acids, surface-active agents, antistatic agents, e.g. non-ionic antistatic agents including a fluorocarbon group as e.g. in F3C(CF2)6CONH(CH2CH2O)-H, ultraviolet light absorbing compounds, white light reflecting and/or ultraviolet radiation reflecting pigments, colloidal silica, and/or optical brightening agents.
  • antistatic agents e.g. non-ionic antistatic agents including a fluorocarbon group as e.g. in F3C(CF2)6CONH(CH2CH2O)-H
  • ultraviolet light absorbing compounds e.g. in F3C(CF2)6CONH(CH2CH2O)-H
  • white light reflecting and/or ultraviolet radiation reflecting pigments e.g. in colloidal silica, and/or optical brightening agents.
  • the at least two heat-sensitive layers that are separated from each other by at least one heat-attenuating spacer layer, not necessarily have the same composition.
  • the heat-sensitive layers may have different thickness and coverage of said ingredients.
  • Direct thermal imaging can be used for both the production of transparencies and reflection type prints.
  • the support may be transparent or opaque, e.g. the support has a white light reflecting aspect.
  • a paper base e.g. polyolefine-coated paper base is used which may contain white light reflecting pigments, optionally also applied in an interlayer between the recording layer and said base.
  • said base may be colourless or coloured, e.g. has a blue colour.
  • a transparent support of the heat-sensitive recording material according to the present invention is preferably a thin flexible resin carrier made e.g. from a cellulose ester, e.g. cellulose triacetate, polypropylene, polycarbonate or polyester, e.g. polyethylene terephthalate.
  • the support may be in sheet, ribbon or web form and may be subbed if need be to improve the adherence to the thereon coated heat-sensitive recording layer.
  • the coating of the heat-sensitive layers may proceed by any coating technique e.g. as described in Modern Coating and Drying Technology, edited by Edward D. Cohen and Edgar B. Gutoff, (1992) VCH Publishers Inc. 220 East 23rd Street, Suite 909 New York, NY 10010, U.S.A.
  • the recording materials of the present invention are particularly suited for use in thermographic recording techniques operating with thermal printheads.
  • Suitable thermal printheads are e.g. a Fujitsu Thermal Head (FTP-040 MCS001), a TDK Thermal Head F415 HH7-1089, and a Rohm Thermal Head KE 2008-F3.
  • an image can be obtained by image-wise heating the above defined recording materials while moving the recording material with its imaging side in contact with a stationary thermal head.
  • the recording material locally reach a temperature of up to 400°C by varying the number of heat pulses given off by the thermal head. By varying the number of heat pulses the density of the corresponding image pixel is varied correspondingly.
  • the imagewise heating of an imaging layer proceeds through a contacting but removable resin sheet or web wherefrom during said heating no transfer of imaging material to the printhead can take place.
  • a protective coating is applied thereto.
  • Such coating may have the same composition as an anti-sticking coating or slipping layer which is applied in thermal dye transfer materials at the rear side of the dye donor material.
  • a slipping layer being said outermost layer may comprise a dissolved lubricating material and/or particulate lubricating material, e.g. talc particles, optionally protruding from the outermost layer.
  • suitable lubricating materials are a surface active agent, a liquid lubricant, a solid lubricant or mixtures thereof, with or without a polymeric binder.
  • the surface active agents may be any agents known in the art such as carboxylates, sulfonates, phosphates, aliphatic amine salts, aliphatic quaternary ammonium salts, polyoxyethylene alkyl ethers, polyethylene glycol fatty acid esters, fluoroalkyl C2-C20 aliphatic acids.
  • liquid lubricants examples include silicone oils, e.g. BAYSILONE ⁇ l (tradename of BAYER AG, Germany), synthetic oils, saturated hydrocarbons and glycols.
  • solid lubricants include various higher alcohols such as stearyl alcohol, fatty acids and fatty acid esters.
  • Suitable slipping layer compositions are described in e.g. EP 138483, EP 227090, US-P 4,567,113, 4,572,860 and 4,717,711 and in published European patent application 311841.
  • a suitable slipping layer being here an outermost layer at the recording layer side comprises as binder a styrene-acrylonitrile copolymer or a styrene-acrylonitrile-butadiene copolymer or a mixture hereof and as lubricant in an amount of 0.1 to 10 % by weight of the binder (mixture) a polysiloxane-polyether copolymer or polytetrafluoroethylene or a mixture hereof.
  • Another suitable outermost slipping layer may be obtained by coating a solution of at least one silicon comound and a substance capable of forming during the coating procedure a polymer having an inorganic backbone which is an oxide of a group IVa or IVb element as described in published European patent application 0554576.
  • a subbed polyethylene terephthalate support having a thickness of 100 ⁇ m was doctor blade-coated from a coating composition containing methyl ethyl ketone as a solvent and the following ingredients so as to obtain thereon after drying the following recording layer containing : silver behenate 3.20 g/m2 polyvinyl butyral (BUTVAR B79-tradename) 3.20 g/m2 reducing agent S as defined hereinafter 0.60 g/m 3,4-dihydro-2,4-dioxo-1,3,2H-benzoxazine 0.22 g/m2 BAYSILON ⁇ l (tradename) 12 mg/m2 Reducing agent S is a polyhydroxy spiro-bis-indane, viz. 3,3,3',3'-tetramethyl-5,6,5',6'-tetrahydroxy-spiro-bis-indane.
  • thermosensitive imaging layer containing: silver behenate 1.60 g/m2 polyvinyl butyral (BUTVAR B79-tradename) 1.60 g/m2 reducing agent S as defined hereinafter 0.30 g/m2 3,4-dihydro-2,4-dioxo-1,3,2H-benzoxazine 0.11 g/m2 BAYSILON ⁇ l A (tradename) 6 mg/m2
  • thermosensitive imaging layer Onto said first thermosensitive imaging layer a spacer layer was applied from the following aqueous polymer dispersion: 25 % latex of copoly(ethyl acrylate, methylmethacrylate methacrylic acid) (50/33.5/16.5) 10 g ULTRAVON W (tradename of Ciba Geigy) wetting agent 10 mg
  • the solids coverage after drying was 25 g/m2.
  • thermosensitive imaging layer Onto said dried spacer layer a hydrophilic barrier layer on the basis of gelatin was coated from aqueous medium.
  • the coverage of gelatin after drying was 2 g/m2.
  • thermosensitive imaging layer having the same composition as the first imaging layer was coated and dried.
  • Both said recording materials A and B were exposed to a pattern of linearly increasing amounts of heat in a thermal head printer built for thermosensitometric purposes, using a same separatable polyethylene terephthalate ribbon of 6 ⁇ m thick between the thermal print head and outermost heat-sensitive layer of the recording materials.
  • the optical density was measured in transmission with MacBeth TD 904 densitometer behind ortho-filter having its main transmission in the green part (500 nm to 600 nm) of the visible spectrum.
  • thermosensitive (non-invention) recording material A was the same as described in Example 1.
  • a polyethylene terephthalate support having a thickness of 100 ⁇ m was doctor blade-coated at a wet coating thickness of 27 g/m2 from a coating composition containing 100 g of methyl ethyl ketone as solvent and the following ingredients so as to obtain after drying a coated layer C1 having the following composition: silver behenate 1.60 g/m2 polyvinyl butyral (BUTVAR B79-tradename) 1.60 g/m2 reducing agent S as defined hereinbefore 0.30 g/m2 3,4-dihydro-2,4-dioxo-1,3,2H-benzoxazine 0.11 g/m2 BAYSILON ⁇ l A (tradename) 6.0 mg/m2
  • Material C2 has the same composition as material C1 with the difference that the polyethylene terephthalate support had a thickness of 8 ⁇ m.
  • Recording material C was prepared by laminating material C2 onto material C1 with its 8 ⁇ m thick support into contact with the thermosensitive layer of material C1.
  • the lamination proceeded with a commercial roll laminator with a lamination speed of 50 cm/minute while keeping the laminator rollers at 80 °C
  • Said recording materials A and C were exposed to a pattern of linearly increasing amounts of heat in a thermal head printer built for thermosensitometric purposes, using a same separatable polyethylene terephthalate ribbon of 6 ⁇ m thick between the thermal print head and outermost heat-sensitive layer of the recording materials.
  • the optical density was measured in transmission with a MacBeth TD 904 densitometer behind ortho-filter having its main transmission in the green part (500 nm to 600 nm) of the visible spectrum.
  • the two heat-sensitive layers of invention material C are identical. It is possible however to make them different in composition and/or thickness whereby the steepness of the sensitometric curve can be tailor-make, e.g. the toe can be made less steep while maintaining the steepness of the shoulder part.

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  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Heat Sensitive Colour Forming Recording (AREA)
EP94203655A 1994-01-14 1994-12-16 Matériau d'enregistrement pour un procédé direct de formation d'images thermiques Expired - Lifetime EP0663301B1 (fr)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3080254A (en) * 1959-10-26 1963-03-05 Minnesota Mining & Mfg Heat-sensitive copying-paper
EP0119102A2 (fr) * 1983-03-15 1984-09-19 Minnesota Mining And Manufacturing Company Renforcement de l'image pour éléments photothermographiques
WO1987003541A2 (fr) * 1985-12-16 1987-06-18 Polaroid Corporation Nouveaux composes et nouveau materiau d'enregistrement les utilisant
EP0512476A1 (fr) * 1991-05-06 1992-11-11 Polaroid Corporation Matériau de formation d'images à diffusion de colorant réduite
EP0516163A1 (fr) * 1991-05-31 1992-12-02 Polaroid Corporation Procédés inversibles de formation d'images contrôlés par oxydoréduction
US5264334A (en) * 1993-02-22 1993-11-23 Eastman Kodak Company Thermally processable imaging element comprising a barrier layer

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3080254A (en) * 1959-10-26 1963-03-05 Minnesota Mining & Mfg Heat-sensitive copying-paper
EP0119102A2 (fr) * 1983-03-15 1984-09-19 Minnesota Mining And Manufacturing Company Renforcement de l'image pour éléments photothermographiques
WO1987003541A2 (fr) * 1985-12-16 1987-06-18 Polaroid Corporation Nouveaux composes et nouveau materiau d'enregistrement les utilisant
EP0512476A1 (fr) * 1991-05-06 1992-11-11 Polaroid Corporation Matériau de formation d'images à diffusion de colorant réduite
EP0516163A1 (fr) * 1991-05-31 1992-12-02 Polaroid Corporation Procédés inversibles de formation d'images contrôlés par oxydoréduction
US5264334A (en) * 1993-02-22 1993-11-23 Eastman Kodak Company Thermally processable imaging element comprising a barrier layer

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