US3811773A - Thermographic copying - Google Patents

Thermographic copying Download PDF

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Publication number
US3811773A
US3811773A US00149039A US14903971A US3811773A US 3811773 A US3811773 A US 3811773A US 00149039 A US00149039 A US 00149039A US 14903971 A US14903971 A US 14903971A US 3811773 A US3811773 A US 3811773A
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US
United States
Prior art keywords
gelatin
information according
recording information
layer
light
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00149039A
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English (en)
Inventor
M Vrancken
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Agfa Gevaert NV
Original Assignee
Agfa Gevaert NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to GB50441/65A priority Critical patent/GB1154568A/en
Priority to NL6608711A priority patent/NL6608711A/xx
Priority to BE683054D priority patent/BE683054A/xx
Priority to CH1701966A priority patent/CH477295A/de
Application filed by Agfa Gevaert NV filed Critical Agfa Gevaert NV
Priority to US00149039A priority patent/US3811773A/en
Application granted granted Critical
Publication of US3811773A publication Critical patent/US3811773A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03D—APPARATUS FOR PROCESSING EXPOSED PHOTOGRAPHIC MATERIALS; ACCESSORIES THEREFOR
    • G03D13/00—Processing apparatus or accessories therefor, not covered by groups G11B3/00 - G11B11/00
    • G03D13/002—Heat development apparatus, e.g. Kalvar
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
    • B41C1/00—Forme preparation
    • B41C1/14—Forme preparation for stencil-printing or silk-screen printing
    • B41C1/148—Forme preparation for stencil-printing or silk-screen printing by a traditional thermographic exposure using the heat- or light- absorbing properties of the pattern on the original, e.g. by using a flash
    • 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
    • B41M5/36—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using a polymeric layer, which may be particulate and which is deformed or structurally changed with modification of its' properties, e.g. of its' optical hydrophobic-hydrophilic, solubility or permeability properties
    • B41M5/368—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using a polymeric layer, which may be particulate and which is deformed or structurally changed with modification of its' properties, e.g. of its' optical hydrophobic-hydrophilic, solubility or permeability properties involving the creation of a soluble/insoluble or hydrophilic/hydrophobic permeability pattern; Peel development
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B27/00—Photographic printing apparatus
    • G03B27/02—Exposure apparatus for contact printing
    • G03B27/14—Details
    • G03B27/18—Maintaining or producing contact pressure between original and light-sensitive material
    • G03B27/22—Maintaining or producing contact pressure between original and light-sensitive material by stretching over a curved surface
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B27/00—Photographic printing apparatus
    • G03B27/02—Exposure apparatus for contact printing
    • G03B27/14—Details
    • G03B27/30—Details adapted to be combined with processing apparatus
    • G03B27/306—Heat development

Definitions

  • ABSTRACT A process .for the reproduction of a transparent original having infrared radiation and visible light absorptive image markings thereon by exposing the original to infrared radiation and/or light while the image markings are arranged in heat-conductive contact with a recording layer composed at least 80 percent by weight of gelatin and havingdistributed therethrough a finely divided substance transforming absorbed visible and infrared radiation into heat, for a period not longer than 10 second and developing the recording layer by washing with waterto remove the gelatin in the area corresponding with the non-image area of the original.
  • the present invention relates to a method for recording'and reproducing information by means of electromagnetic radiation which by absorption in a thermosensitive layer produces an increase in temperature therein.
  • a documenthaving a transparent or slightly diffusing support is copied by placing the printed characters of the document in heat conductive contact with the gelatin layer which may contain a pigment that does not absorb infra-red radiation and exposing the gelatin layer to infra-red radiation through the support of the document.
  • a laterally reversed master sheet is thus obtained and accordingly, right-reading positive copies are obtained by transfer. In this case only one-sided documents can be copied.
  • an original comprising a heat-diffusing support is placed with that support in contact with the gelatin layer which may contain colouring materials, carbon black, etc., and exposure is made through the document towards the gelatin layer.
  • the copy obtained on a receivingsheet by transfer is laterally reversed and the image-sharpness is not of high quality.
  • a process for recording information wherein is used a recording material comprising a gelatin layer containing a uniformly distributed visible and infra-red lightab sorbing substance which as a result of such absorption becomes heated; and this gelatin layer is exposed, through a copying light transmitting original disposed with its image-markings in direct thermal contact with the gelatin layer of said recording material, said image markings being light-absorbing and heatable by copying lightin the wavelength range of visible and infra-red light, the exposure being of a'duration not longer than second and of such intensity that a substantial increase in the swelling tendency of the gelatin in said recording layer is produced selectively in correspondence with the non-image parts of said original but insufficient to produce a substantial increase in the swellimage area.
  • this record may be rendered visible in or on the said recording material and/or may be used for forming one or more non laterally reversed copies on another material.
  • An important discovery leading to the invention is that by a sufficiently brief exposure to light (an exposure time not higher than 10 sec.) the existence of a heat-conductive relationship between the lightabsorbing image portions and the gelatinrecording layer is of no effect or substantially no effect in forming the record in the gelatin recording layer.
  • the record is produced by virtue of the internal heating of the gelatin recording layer where it is irradiated with light passing through the non-image areas of the original. Consequently there is no need to insulate the light-absorbing image portions from the gelatin recording layer; they can be maintained in intimate contact during the exposure, by pressing the original and the recording material together.
  • the exposure is carried out by means of electromagnetic radiation the greater part of which (at least percent of the ir-. radiation energy) is composed of electromagnetic radiation of the visible spectrum.
  • sufficient intensity at least 0.2 watt sec per'sq. cm and preferably 0.50 to 1.0 watt. sec per sq. cm
  • sufficient heat can be produced in the light-in-heatconverting particles distributed throughout the gelatin layer which are irradiated, for suddenly increasing the temperature of the gelatin surrounding such particles 1 and conferring on such surrounding gelatin a substantial increase in swelling tendency in water and solubility in 'water or an aqueous composition.
  • the dosage of short duration high intensity exposing light is such'that not enough heat can be absorbed in he light-absorbing image portions of the original for being transferred to the gelatin recording layer to bring about any significant differentiation in water solubility.
  • the copying light-absorbing substance in the gelatin layer may be dispersed or dissolved in the gelatin layer.
  • One or more than one such substance may be present in one and the same layer.
  • a copying lightabsorbing substance in such a proportion that the absorption therein of light energy produced on flash exposure effects a sufficient increase in temperature of the gelatin to increase its water solubility to such an extent that it can be dissolved in the heated areas by coldwater (2025"C).
  • the light absorbing substance is preferably present therein in such an amount that at least 80 percent of such light is absorbed and converted into heat.
  • the optical density of the gelatin layer be comprised between 1 and 3, the gelatin content of such layer being in that case between 1 and 4' g per square metre.
  • the gelatin recording layer may contain light-absorbing substance to an optical density of at least 1.
  • the gelatin recording layer may be applied to a transparent support but this is not essential.
  • An opaque or translucent support may be used.
  • the said recording layer may be applied to atransparent film, a paper support or a metal support.
  • the selected support iscoated with a composition preferably containing at least 80 percent by weight of gelatin. That gelatin composition contains one or more dissolved or finely dispersed visible light absorbing or visible light and infra-red absorbing substances which transform such light into heat.
  • Certain preferred substances which absorb visible light and infra-red light and convert the absorbed radiation into heat are finely divided carbon black, graphite, prussian blue, oxides, sulphides or carbonates of heavy metals, particularly of those heavy metals having an atomic weight between 45 and 210, such as manganese or lead sulphide or such heavy metals themselves in finely divided state, e.g., silver, bismuth, lead, iron, cobalt and nickel. Carbon particles and silver are among the most suitable substances.
  • dispersed light absorbing particles preferably having a particle size or an average particle size not greater than 0.1 u.
  • the gelatin of the heat-sensitive layer may be of the type of gelatin normally used in silver halide photography.
  • a sufficient Bloom gel strength (preferably at least 150) of the gelatin is important in cases wherein the gelatin has to be swollen and transferred in swollen state to a receiving support, e.g. a screening master blank such as a Japan paper, however, in the case that the original is to be reproduced merely by exposure and washing away of the heated areas a high bloom gel strength of the gelatin is not necessary.
  • a receiving support e.g. a screening master blank such as a Japan paper
  • the differential swelling tendency of the gelatin layer can be observed directly when moistening the layer with water.
  • the swelling tendency and solubility of the gelatin varies with the hardening degree. After a sudden heating above C a substantially unhardened gelatin layer will have regions which can be washed away completely by water at 25C.
  • the gelatin layer contains during the exposure uniformly distributed coloured substances which absorb light of a determined part of the visible spectrum and convert it into heat.
  • a gelatin layer made spectrally sensitive in this way can be used for recording coloured originals in terms of differences in solubility and in swelling tendency in water.
  • mixtures of said coloured substances can also be used, so that light of the entire visible spectrum is absorbed.
  • the substances need not absorb exclusively in the range of the visible spectrum; they may also absorb in the infrared region.
  • the coloured substances or mixtures of said substances preferably absorb light corresponding to at least one of the primary colours (red, green, blue) or subtractive colours (cyan, magenta, yellow).
  • Substances that absorb visible light of a part of the visible spectrum and wherein absorbed light energy is converted into heat are e.g. dyes belonging to the which absorb visible light and convert it into heat, reference is particularly made to Belgian Patent Specification 7,502 and the UK. Patent Specification 1,160,221 corresponding with the US. Pat. application Ser. No. 550,834, which specifications are deemed to classes of the azo dyes, the triarylmethane dyes, the xanthene dyes, the acridine dyes, the methine dyes, the azine dyes, the phthalocyanine dyes, the anthraquinone dyes and allied dyes.
  • Said substances can be used in dispersed or dissolved condition; when they are used in dispersed form they should preferably have a grain size lowe than 0.1 1.4..
  • spectrally sensitive gelatin layers when using spectrally sensitive gelatin layers, it is possible to produce printing masters suitable for colour printing and for producing multicolour copies of colour originals.
  • three materials are used that contain a heat-sensitive gelatin layer comprising a substance which is heated on absorbing red, green and blue light respectively, i.e. a gelatin layer containing a cyan dye,
  • Said dyes may be dyes suitable for hectographic printing.
  • Multicolour prints can be produced by using the three exposed materials to prepare three separate masters which are used to print in register.
  • three separate gelatin layers can be used which are sensitized'for blue, green and red respectively by a blue, green and red dye or pigment that is uniformly distributed therein.
  • a blue, green and red dye or pigment that is uniformly distributed therein.
  • the effectiveness of the recording substantially depends on the intensity of the radiant energy.
  • a gelatin recording layer that does not provide a I sufficient differentiation in swelling tendency with a particular source of electromagnetic radiation energy may be fully effective if the energy level is substantially increased.
  • Lamp structures and exposure systems producing electromagnetic radiation at least 70 percent of which consists of visible light (in other words containing only small amounts of U.V. light and infra-red light) and which are capable of providing high intensity radiation in a very small lapse are preferably used.
  • Radiation sources emitting visible light of high intensity in a very small lapse of time are so-called flash lamps and more particularly the discharge lamps containing a noble gas.
  • a Xenon gas discharge lamp which can supply an energy of 300l,000 watt. sec in a time interval of to 10" seconds and can irradiate the recording layer with an energy of at least 0.2 watt. sec per sq. cm and preferably in the range of 0.2 to 1.5 watt. sec per sq.
  • a gas discharge lamp is used, which is in the form of a thin tube fitted in a hollow glass cylinder in order to makepossible a uniform exposure of the recording material applied according to the periphery of the cylinder.
  • lamps with a lower energy output can be used if the emitted light energy is focused onto a relatively small heat-sensitive area.
  • a gas discharge lamp with an energy output of 40 watt. sec. is suited for copying 6 cm X 6 cm and 6 cm X 9 cm originals on a heat-sensitive material as described in the present invention.
  • exposure may be progressive and intermittent.
  • the heat-sensitive material may be scanned through an original with a light-spot of high intensity, e.g. a laser beam, or may be progressively exposed through a slit wherein, e.g., copying light of a continuously emitting tube-like radiation source is focused.
  • Example 1 A poly(ethylene terephthalate) support of 0.1 mm thickness provided with a subbing layer for gelatin is coated with the following composition pro rata of 30 g/sq.m:
  • the layer is dried at,20C.
  • thermosensitive gelatin layer 6 is laid on a photographic silver image containing transparency 2 having radiationabsorbing markings 3 and radiation transmitting parts 4, the thermosensitive gelatin layer 6 being in contact with the image layer 7 of the silver image transparency.
  • a xenon glass discharge lamp 110 is placed which at the discharge between the electrodes 11 produces a radiation energy of 600 watt.
  • Example 2 A cellulose triacetatesupport of 0.12 mm thickness provided with a subbing layer for gelatin is coated with the following composition pro rata of 50 g per sq.m
  • Example 3 A poly(ethylene terepththalate) support of 0.1 mm thickness provided with a subbing layer for gelatin is coated with the following composition pro rata of 50 g per sq.m:
  • Example 4 v A paper support weighing 120 g per sq.m., provided on both sides with a polyethylene coating and a subbing layer for gelatin, is coated with the following composition pro rata of 50g per sq. m.:
  • aqueous solution of gelatin having a Bloom gel strength of 190 410 g 50 aqueous dispersion of carbon black of particle size 0.1 p. 30 g water 50 g 5 aqueous solution of sodium tetradecylsulphate 25 g a finely divided substance transforming absorbed visible and infrared radiation into heat, said substance being present in such an amount that at least about 80 percent of said radiation towhich said recording layer is exposed is absorbed and converted into heat, said exposure being of a duration not longer than 10 second and of such an intensity that a substantial increase in the swelling tendency of the gelatin in said recording layer is produced selectively in correspondence with the non-image parts of said original but insufficient to produce a substantial increase in the swelling tendency of the gelatin in the area of the recording layer corresponding to the image area of the original, and developing said layer by washing with water to remove the gelatin in the area corresponding to said non-image area.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Optics & Photonics (AREA)
  • Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
  • Thermal Transfer Or Thermal Recording In General (AREA)
  • Heat Sensitive Colour Forming Recording (AREA)
US00149039A 1965-11-26 1971-06-01 Thermographic copying Expired - Lifetime US3811773A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
GB50441/65A GB1154568A (en) 1965-11-26 1965-11-26 Improvements relating to Thermographic Copying.
NL6608711A NL6608711A (ja) 1965-11-26 1966-06-23
BE683054D BE683054A (ja) 1965-11-26 1966-06-24
CH1701966A CH477295A (de) 1965-11-26 1966-11-28 Wärmekopierverfahren
US00149039A US3811773A (en) 1965-11-26 1971-06-01 Thermographic copying

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB50441/65A GB1154568A (en) 1965-11-26 1965-11-26 Improvements relating to Thermographic Copying.
US56031466A 1966-06-24 1966-06-24
US00149039A US3811773A (en) 1965-11-26 1971-06-01 Thermographic copying

Publications (1)

Publication Number Publication Date
US3811773A true US3811773A (en) 1974-05-21

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US00149039A Expired - Lifetime US3811773A (en) 1965-11-26 1971-06-01 Thermographic copying

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US (1) US3811773A (ja)
BE (1) BE683054A (ja)
CH (1) CH477295A (ja)
GB (1) GB1154568A (ja)
NL (1) NL6608711A (ja)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0007784A1 (en) * 1978-07-21 1980-02-06 Process Shizai Co. Ltd. Thermal recording material
EP0514145A1 (en) * 1991-05-14 1992-11-19 Du Pont (UK) Limited Thermographic material
US5948599A (en) * 1992-11-18 1999-09-07 Agfa Gevaert Nv Method of forming an image in a printing plate

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0908305B2 (en) * 1997-10-08 2006-07-19 Agfa-Gevaert A method for making positive working printing plates from a heat mode sensitive imaging element
US6060218A (en) * 1997-10-08 2000-05-09 Agfa-Gevaert, N.V. Method for making positive working printing plates from a heat mode sensitive image element
EP0908306B3 (en) * 1997-10-08 2009-08-05 Agfa-Gevaert A method for making positive working printing plates from a heat mode sensitive imaging element
US6004728A (en) * 1997-10-08 1999-12-21 Agfa-Gevaert, N.V. Method for making positive working printing plates from a heat mode sensitive image element
US6235451B1 (en) 1997-10-08 2001-05-22 Agfa-Gevaert Method for making positive working printing plates from a heat mode sensitive image element
US6251563B1 (en) 1997-10-08 2001-06-26 Agfa-Gevaert, N.V. Method for making positive working printing plates from a heat mode sensitive image element
EP0908307B1 (en) * 1997-10-08 2003-11-26 Agfa-Gevaert A method for making positive printing plates from a heat mode sensitive imaging element
EP0908304B1 (en) * 1997-10-08 2003-04-02 Agfa-Gevaert A method for making positive working printing plates from a heat mode sensitive imaging element
EP0940266B1 (en) * 1998-03-06 2002-06-26 Agfa-Gevaert A heat mode sensitive imaging element for making positive working printing plates.
US6342336B2 (en) 1998-03-06 2002-01-29 Agfa-Gevaert Heat mode sensitive imaging element for making positive working printing plates
EP0943451B3 (en) * 1998-03-14 2018-12-12 Agfa Graphics NV A heat mode imaging element and a method for making positive working printing plates from said heat mode imaging element
US6153353A (en) * 1998-03-14 2000-11-28 Agfa-Gevaert, N.V. Method for making positive working printing plates from a heat mode sensitive imaging element

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3121162A (en) * 1960-04-16 1964-02-11 Eastman Kodak Co Thermographic colloid transfer process
US3298833A (en) * 1960-12-30 1967-01-17 Gen Electric Method for storing information
US3476578A (en) * 1965-06-22 1969-11-04 Agfa Gevaert Nv Thermographic method for producing thermostable prints
US3514597A (en) * 1966-04-05 1970-05-26 Agfa Gevaert Nv Thermographic recording processes and materials
US3523791A (en) * 1965-06-22 1970-08-11 Agfa Gevaert Nv Process of thermographic copying
US3645204A (en) * 1967-09-15 1972-02-29 Burroughs Corp Methods of preparing and composing relief printing member

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3121162A (en) * 1960-04-16 1964-02-11 Eastman Kodak Co Thermographic colloid transfer process
US3298833A (en) * 1960-12-30 1967-01-17 Gen Electric Method for storing information
US3476578A (en) * 1965-06-22 1969-11-04 Agfa Gevaert Nv Thermographic method for producing thermostable prints
US3523791A (en) * 1965-06-22 1970-08-11 Agfa Gevaert Nv Process of thermographic copying
US3514597A (en) * 1966-04-05 1970-05-26 Agfa Gevaert Nv Thermographic recording processes and materials
US3645204A (en) * 1967-09-15 1972-02-29 Burroughs Corp Methods of preparing and composing relief printing member

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0007784A1 (en) * 1978-07-21 1980-02-06 Process Shizai Co. Ltd. Thermal recording material
EP0514145A1 (en) * 1991-05-14 1992-11-19 Du Pont (UK) Limited Thermographic material
US5948599A (en) * 1992-11-18 1999-09-07 Agfa Gevaert Nv Method of forming an image in a printing plate

Also Published As

Publication number Publication date
BE683054A (ja) 1966-11-27
CH477295A (de) 1969-08-31
NL6608711A (ja) 1966-11-25
GB1154568A (en) 1969-06-11

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