EP0441208B1 - Use of azo-dyes for thermal transfer printing - Google Patents

Use of azo-dyes for thermal transfer printing Download PDF

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Publication number
EP0441208B1
EP0441208B1 EP91101022A EP91101022A EP0441208B1 EP 0441208 B1 EP0441208 B1 EP 0441208B1 EP 91101022 A EP91101022 A EP 91101022A EP 91101022 A EP91101022 A EP 91101022A EP 0441208 B1 EP0441208 B1 EP 0441208B1
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Prior art keywords
alkyl
alkoxy
phenyl
formula
substituted
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German (de)
French (fr)
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EP0441208A1 (en
Inventor
Volker Bach
Karl-Heinz Etzbach
Sabine Gruettner
Helmut Reichelt
Ruediger Sens
Gunther Lamm
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BASF SE
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BASF SE
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Classifications

    • 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
    • B41M5/385—Contact thermal transfer or sublimation processes characterised by the transferable dyes or pigments
    • B41M5/388—Azo dyes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/913—Material designed to be responsive to temperature, light, moisture
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/914—Transfer or decalcomania

Definitions

  • the main heat source used is a thermal head with which short heating pulses lasting a fraction of a second can be emitted.
  • a transfer sheet which contains the dye to be transferred together with one or more binders, a carrier material and possibly other auxiliaries such as release agents or crystallization-inhibiting substances is heated from the rear by the thermal head.
  • the dye diffuses from the transfer sheet into the surface coating of the substrate, e.g. into the plastic layer of a coated paper.
  • the main advantage of this method is that the amount of ink transferred and thus the color gradation can be controlled in a targeted manner via the energy to be delivered to the thermal head.
  • Thermal transfer printing generally uses the three subtractive primary colors yellow, magenta and cyan, possibly also black, whereby the dyes used must have the following properties for optimal color recording: easy thermal transferability, low tendency to migrate within or from the surface coating of the recording medium at room temperature , high thermal and photochemical stability as well as resistance to moisture and chemicals, no tendency to crystallize when storing the transfer sheet, a suitable color for the subtractive color mixture, a high molar absorption coefficient and easy technical accessibility.
  • magenta dyes previously used cannot convince. This also applies, for example, to the azo dyes described in US Pat. No. 4,764,178 and recommended for thermal transfer, which are similar to azo dyes I and have coupling components based on aniline, tetrahydroquinoline, aminoquinoline or julolidine.
  • azo dyes I themselves are known per se or according to known methods, for example according to the older German patent application P 38 33 443.7, according to 0. Annen et al., Rev. Prog. Coloration 17, 72-85 (1987) or MA Weaver and L. Shuttleworth, Dyes and Pigments 3, 81-121 (1982).
  • the invention was therefore based on the object of finding suitable red and blue dyes for thermal transfer printing which come closer to the required property profile than the dyes known hitherto.
  • a method for transferring azo dyes by diffusion from a support onto a plastic-coated substrate using a thermal head was found, which is characterized in that a support is used for this purpose, on which one or more of the azo dyes I defined at the outset are located.
  • Suitable alkyl radicals Rl , R 2, R 3, R 4, R5, R6, R7, R 8 , R 11 , R12, R 13 , R 15 or R 16 are especially methyl, ethyl, propyl, isopropyl and butyl, in addition also isobutyl, sec-butyl and tert-butyl.
  • the radicals R 1 , R 2 , R 3 , R 5 , R 6 , R 7 , R 8 , R 15 or R 16 are, for example, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, 2-methylpentyl, heptyl, To name octyl, 2-ethylhexyl and the isomer mixture isooctyl and cyclohexyl.
  • R 1 , R 2 , R 3 , R 5 , R 6 , R 7 , R 8 , R 15 or R 16 are, for example, nonyl and decyl and their isomer mixtures isononyl and isodecyl.
  • undecyl, dodecyl, tridecyl and its isomer mixture isotridecyl, tetradecyl, pentadecyl are also suitable as radicals R 1 , R 2 or R 3 , and also hexadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl as radicals R 2 and R 3 .
  • alkoxyalkyl groups those which contain up to 8 carbon atoms are also suitable as radicals R 8 and those with up to 12 carbon atoms are also suitable as radicals R 15 or R 16 .
  • Preferred alkoxy groups as R 2 , R 3 , R 8 , R 11 or R 12 are, for example: methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy and sec-butoxy.
  • R 8 in particular R 2 or R 3, are furthermore, for example, pentyloxy, isopentyloxy, neopentyloxy, hexyloxy, octyloxy and 2-ethylhexyloxy.
  • radicals R 2 or R 3 are, for example, nonyloxy or decyloxy, and also undecyloxy, dodecyloxy, tridecyloxy, tetradecyloxy and pentadecyloxy.
  • R 8 radicals can also be alkylthio groups, such as preferably methylthio, ethylthio and 2-cyanoethylthio, in addition propylthio, isopropylthio, butylthio, pentylthio, hexylthio, heptylthio, octylthio, 2-ethylhexylthio, 2-ethoxycarbonylethylthio and especially 2-methoxycarbonyl.
  • alkylthio groups such as preferably methylthio, ethylthio and 2-cyanoethylthio, in addition propylthio, isopropylthio, butylthio, pentylthio, hexylthio, heptylthio, octylthio, 2-ethylhexylthio, 2-ethoxycarbonylethylthio and especially 2-methoxycarbonyl.
  • radicals R 1 are C 1 -C 8 -alkyl, including in particular methyl and isopropyl, cyclohexyl, phenyl, which can also carry methoxy, sulfonamido or chlorine as substituents, and also benzyl.
  • Preferred radicals R 1 are furthermore thien-3-yl and especially thien-2-yl, furan-3-yl and especially furan-2-yl as well as pyrid-2-yl, pyrid-4-yl and especially pyrid-3- yl.
  • Preferred radicals R 2 or R 3 of the alkyl radicals mentioned are those with up to 12 C atoms, including in particular methyl, ethyl and propyl, of the cyanoalkyl and alkoxy radicals mentioned those with up to 10 C atoms.
  • Particularly preferred radicals R 2 or R 3 have the formula Ila with methyl or ethyl as the radical R4 '.
  • the dyes to be used according to the invention are distinguished from the red and blue dyes with coupling components based on aniline, which have been used for thermal transfer printing to date, by the following properties: easier thermal transferability, improved migration properties in the recording medium at room temperature, higher thermal stability, higher lightfastness, better resistance to moisture and Chemicals, better solubility in the production of the printing ink, higher color strength and easier technical accessibility.
  • the azo dyes show a significantly better color purity, especially in dye mixtures, and result in improved black prints.
  • the transfer sheets required as dye donors for the thermal transfer printing process according to the invention are prepared as follows:
  • the azo dyes are in an organic solvent such as isobutanol, methyl ethyl ketone, methylene chloride, chlorobenzene, toluene, tetrahydrofuran or mixtures thereof, with one or more binders and possibly other auxiliaries such as release agents or crystallization-inhibiting substances processed into a printing ink, which preferably contains the dyes in a molecularly dispersed solution.
  • the printing ink is then applied to an inert support and dried.
  • Suitable binders for the use of the azo dyes according to the invention are all materials which are soluble in organic solvents and which are known to be used for thermal transfer printing, e.g. Cellulose derivatives such as methyl cellulose, hydroxypropyl cellulose, cellulose acetate or cellulose acetobutyrate, especially ethyl cellulose and ethyl hydroxyethyl cellulose, starch, alginates, alkyd resins such as polyvinyl alcohol or polyvinyl pyrrolidone, and especially polyvinyl acetate and polyvinyl butyrate.
  • Cellulose derivatives such as methyl cellulose, hydroxypropyl cellulose, cellulose acetate or cellulose acetobutyrate, especially ethyl cellulose and ethyl hydroxyethyl cellulose, starch, alginates, alkyd resins such as polyvinyl alcohol or polyvinyl pyrrolidone, and especially polyvinyl acetate and
  • polymers and copolymers of acrylates or their derivatives such as polyacrylic acid, polymethyl methacrylate or styrene acrylate copolymers, polyester resins, polyamide resins, polyurethane resins or natural resins such as e.g. Gum arabic into consideration.
  • binders are often recommended, e.g. those made of ethyl cellulose and polyvinyl butyrate in a weight ratio of 2: 1.
  • the weight ratio of binder to dye is usually 8: 1 to 1: 1, preferably 5: 1 to 2: 1.
  • Inert carrier materials are, for example, tissue paper, blotting paper or glassine paper as well as films made of heat-resistant plastics such as polyesters, polyamides or polyimides, these films also being able to be metal-coated.
  • the inert carrier can additionally be coated with a lubricant on the side facing the thermal head in order to prevent the thermal head from sticking to the carrier material.
  • Suitable lubricants are, for example, silicones or polyurethanes, as described in EP-A-216 483.
  • the thickness of the dye carrier is generally 3 to 30 microns, preferably 5 to 10 microns.
  • the substrate to be printed e.g. Paper, for its part, must be coated with a plastic that absorbs the dye during the printing process.
  • a plastic that absorbs the dye during the printing process.
  • Polymeric materials whose glass transition temperature Tg is between 50 and 100 ° C, i.e. e.g. Polycarbonate and polyester. Further details can be found in EP-A-227 094, EP-A-133 012, EP-A-133 011, JP-A-199 997/1986 or JP-A-283 595/1986.
  • a thermal head which can be heated to temperatures up to over 300 ° C., so that the dye transfer takes place within a maximum time of 15 msec.
  • transfer sheets were produced in the usual way from polyester film of 6 to 10 ⁇ m thick, which was provided with an approximately 5 ⁇ m thick transfer layer made of a binder B, which each contained approximately 0.25 g of azo dye I.
  • the weight ratio of binder to dye was 4: 1, unless otherwise stated in the tables below.
  • the substrate to be printed consisted of paper approximately 120 ⁇ m thick, which was coated with an 8 ⁇ m thick plastic layer (Hitachi Color Video Print Paper).
  • the coated side of the encoder and slave was placed on top of one another and wrapped in aluminum foil and heated for two minutes between two hot plates to a temperature between 70 and 80 ° C. With similar samples, this process was repeated three times at a higher temperature between 80 and 120 ° C.
  • the amount of dye diffused into the plastic layer of the receiver is proportional to the optical density, which was determined as absorbance A photometrically after the respective heating to the temperatures given above.
  • the temperature T * at which the extinction reaches the value 1 can also be taken from the application, ie the transmitted light intensity is one tenth of the incident light intensity.
  • the smaller the temperature T * the better the thermal transferability of the investigated dye.
  • binder B used in each case.
  • EC ethyl cellulose
  • PVB polyvinyl butyrate
  • VY Vylon.

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  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Plural Heterocyclic Compounds (AREA)
  • Thermal Transfer Or Thermal Recording In General (AREA)

Description

Die vorliegende Erfindung betrifft die Verwendung von Azofarbstoffen der allgemeinen Formel

Figure imgb0001
für den Thermotransferdruck, in der die Substituenten folgende Bedeutung haben:

  • R1 Wasserstoff;
    • C1-C15-Alkylgruppen, die Phenyl oder Phenoxy als Substituenten tragen können;
    • eine Cyclohexylgruppe, die C1-C5-Alkyl, C1-C5-Alkoxy oder Halogen als Substituenten tragen kann;
    • eine Phenylgruppe, die C1-C5-Alkyl, C1-C5-Alkoxy, Sulfonamido oder Halogen als Substituenten tragen kann;
    • eine Thienylgruppe, die C1-C5-Alkyl oder Halogen als Substituenten tragen kann, eine Furanyl- oder Pyridylgruppe; einen Rest der allgemeinen Formel II
      Figure imgb0002
      in der
      • W gleiche oder verschiedene C2-C6-Alkylengruppen bezeichnet,
      • n 1 bis 6 bedeutet und
      • R4 für eine C1-C4-Alkylgruppe oder eine Phenyl- oder Benzylgruppe steht, die beide jeweils C1-C4-Alkyl oder C1-C4-Alkoxy als Substituenten tragen können;
  • R2, R3 Wasserstoff;
    • Alkyl-, Alkoxy-, Alkoxyalkyl-, Alkanoyloxyalkyl-, Alkoxycarbonyloxyalkyl-, Alkoxycarbonylalkyl-, Halogenalkyl-, Hydroxyalkyl- oder Cyanoalkylgruppen, die jeweils bis zu 15 C-Atome enthalten können und Phenyl, C1-C4-Alkylphenyl, C1-C4-Alkoxyphenyl, Halogenphenyl, Benzyloxy, C1-C4-Alkylbenzyloxy, C1-C4-Alkoxybenzyloxy, Halogenbenzyloxy, Halogen, Hydroxy oder Cyano als Substituenten tragen können;
    • eine Cyclohexylgruppe, die C1-C15-Alkyl, C1-C15-Alkoxy oder Halogen als Substituenten tragen kann;
    • eine Phenylgruppe, die C1-C15-Alkyl, C1-C15-Alkoxy, Benzyloxy oder Halogen als Substituenten tragen kann;
    • einen Rest der oben angegebenen Formel II;
  • D den Rest einer Diazokomponente III
    Figure imgb0003
    wobei Azofarbstoffe der Formel
    Figure imgb0004
    in der die Substituenten R' und R" folgende Bedeutung haben:
    • a) R' =-H, R" =-CH2-C6H5;
    • b) R' = -CH3, R" =-C6H4-4-CH3;
    • c) R'= = -C2H5, R"=-C6H4-3-CH3;
    • d) R' = -CH3, R" =- C6H5,

    und der Formel
    Figure imgb0005
    in der R"' Wasserstoff, Methyl oder Phenyl bedeutet, ausgeschlossen sind,
    sowie speziell ein Verfahren zur Übertragung dieser Azofarbstoffe durch Diffusion von einem Träger auf ein mit Kunststoff beschichtetes Substrat mit Hilfe eines Thermokopfes.
The present invention relates to the use of azo dyes of the general formula
Figure imgb0001
 for thermal transfer printing, in which the substituents have the following meaning:
  • R 1 is hydrogen;
    • C 1 -C 15 alkyl groups which can carry phenyl or phenoxy as substituents;
    • a cyclohexyl group which can carry C 1 -C 5 alkyl, C 1 -C 5 alkoxy or halogen as substituents;
    • a phenyl group which can carry C 1 -C 5 alkyl, C 1 -C 5 alkoxy, sulfonamido or halogen as substituents;
    • a thienyl group which may carry C 1 -C 5 alkyl or halogen as a substituent, a furanyl or pyridyl group; a radical of the general formula II
      Figure imgb0002
       in the
      • W denotes the same or different C 2 -C 6 alkylene groups,
      • n is 1 to 6 and
      • R 4 represents a C 1 -C 4 alkyl group or a phenyl or benzyl group, both of which can each carry C 1 -C 4 alkyl or C 1 -C 4 alkoxy as substituents;
  • R 2, R3 are hydrogen;
    • Alkyl, alkoxy, alkoxyalkyl, alkanoyloxyalkyl, alkoxycarbonyloxyalkyl, alkoxycarbonylalkyl, haloalkyl, hydroxyalkyl or cyanoalkyl groups, each of which can contain up to 15 carbon atoms and phenyl, C 1 -C 4 alkylphenyl, C 1 - C 4 -alkoxyphenyl, halophenyl, benzyloxy, C 1 -C 4 -alkylbenzyloxy, C 1 -C 4 -alkoxybenzyloxy, halobenzyloxy, halogen, hydroxy or cyano can carry as substituents;
    • a cyclohexyl group which can carry C 1 -C 15 alkyl, C 1 -C 15 alkoxy or halogen as substituents;
    • a phenyl group which can carry C 1 -C 15 alkyl, C 1 -C 15 alkoxy, benzyloxy or halogen as substituents;
    • a radical of formula II given above;
  • D the rest of a diazo component III
    Figure imgb0003
     where azo dyes of the formula
    Figure imgb0004
     in which the substituents R 'and R "have the following meaning:
    • a) R '= - H, R "= - CH 2 -C 6 H 5 ;
    • b) R '= -CH 3 , R "= - C 6 H 4 -4-CH 3 ;
    • c) R '= = -C 2 H 5 , R "= - C 6 H 4 -3-CH 3 ;
    • d) R '= -CH 3 , R "= - C 6 H 5 ,

    and the formula
    Figure imgb0005
     in which R "'is hydrogen, methyl or phenyl, are excluded,
    and specifically a method for transferring these azo dyes by diffusion from a support onto a plastic-coated substrate using a thermal head.

Die Technik des Thermotransferdrucks ist allgemein bekannt; als Wärmequelle kommt neben Laser und IR-Lampe vor allem ein Thermokopf zur Anwendung, mit dem kurze Heizimpulse der Dauer von Bruchteilen einer Sekunde abgegeben werden können.The technique of thermal transfer printing is well known; In addition to the laser and IR lamp, the main heat source used is a thermal head with which short heating pulses lasting a fraction of a second can be emitted.

Bei dieser bevorzugten Ausführungsform des Thermotransferdrucks wird ein Transferblatt, das den zu übertragenden Farbstoff zusammen mit einem oder mehreren Bindemitteln, einem Trägermaterial und eventuell weiteren Hilfsmitteln wie Trennmitteln oder kristallisationshemmenden Stoffen enthält, von der Rückseite her durch den Thermokopf erhitzt. Dabei diffundiert der Farbstoff aus dem Transferblatt in die Oberflächenbeschichtung des Substrates, z.B. in die Kunststoffschicht eines beschichteten Papiers.In this preferred embodiment of thermal transfer printing, a transfer sheet which contains the dye to be transferred together with one or more binders, a carrier material and possibly other auxiliaries such as release agents or crystallization-inhibiting substances is heated from the rear by the thermal head. The dye diffuses from the transfer sheet into the surface coating of the substrate, e.g. into the plastic layer of a coated paper.

Der wesentliche Vorteil dieses Verfahrens besteht darin, daß über die an den Thermokopf abzugebende Energie die übertragene Farbmenge und damit die Farbabstufung gezielt gesteuert werden kann.The main advantage of this method is that the amount of ink transferred and thus the color gradation can be controlled in a targeted manner via the energy to be delivered to the thermal head.

Beim Thermotransferdruck werden allgemein die drei subtraktiven Grundfarben Gelb, Magenta und Cyan, gegebenenfalls zusätzlich Schwarz, verwendet, wobei die eingesetzten Farbstoffe für eine optimale Farbaufzeichnung folgende Eigenschaften aufweisen müssen: leichte thermische Transferierbarkeit, geringe Neigung zur Migration innerhalb oder aus der Oberflächenbeschichtung des Aufnahmemediums bei Raumtemperatur, hohe thermische und photochemische Stabilität sowie Resistenz gegen Feuchtigkeit und Chemikalien, keine Tendenz zur Kristallisation bei Lagerung des Transferblattes, einen geeigneten Farbton für die subtraktive Farbmischung, einen hohen molaren Absorptionskoeffizienten und leichte technische Zugänglichkeit.Thermal transfer printing generally uses the three subtractive primary colors yellow, magenta and cyan, possibly also black, whereby the dyes used must have the following properties for optimal color recording: easy thermal transferability, low tendency to migrate within or from the surface coating of the recording medium at room temperature , high thermal and photochemical stability as well as resistance to moisture and chemicals, no tendency to crystallize when storing the transfer sheet, a suitable color for the subtractive color mixture, a high molar absorption coefficient and easy technical accessibility.

Diese Anforderungen sind gleichzeitig nur sehr schwer zu erfüllen. Insbesondere können die bislang verwendeten Magentafarbstoffe nicht überzeugen. Dies trifft beispielsweise auch für die in der US-A-4 764 178 beschriebenen und für den Thermotransfer empfohlenen Azofarbstoffe zu, die den Azofarbstoffen I ähneln und Kupplungskomponenten auf Anilin-, Tetrahydrochinolin-, Aminochinolin- oder Julolidinbasis aufweisen.At the same time, these requirements are very difficult to meet. In particular, the magenta dyes previously used cannot convince. This also applies, for example, to the azo dyes described in US Pat. No. 4,764,178 and recommended for thermal transfer, which are similar to azo dyes I and have coupling components based on aniline, tetrahydroquinoline, aminoquinoline or julolidine.

Aus der älteren, nicht vorveröffentlichten EP-A-432 705 (Stand der Technik nach Artikel 54(3) EPÜ) ist die Verwendung der Azofarbstoffe der Formel

Figure imgb0006

  • (a) R' = -H und R" = -CH2-C6H5; b) R' = -CH3 und R" = -C6H4-4-CH3;
  • c) R' = -C2H5 und R" = -C6H4-3-CH3; d) R' =-CH3 und R" = -C6H5)
    und der Formel
    Figure imgb0007
    (R'" = -H, -CH3 oder -C6H5)
    bekannt.
From the older, not prepublished EP-A-432 705 (prior art under Article 54 (3) EPC) is the use of the azo dyes of the formula
Figure imgb0006
  • (a) R '= -H and R "= -CH 2 -C 6 H 5 ; b) R' = -CH 3 and R" = -C 6 H 4 -4-CH 3 ;
  • c) R '= -C 2 H 5 and R "= -C 6 H 4 -3-CH 3 ; d) R' = -CH 3 and R" = -C 6 H 5 )
    and the formula
    Figure imgb0007
     (R '"= -H, -CH 3 or -C 6 H 5 )
    known.

Die Azofarbstoffe I selbst sind an sich bekannt oder nach bekannten Methoden, z.B. nach der älteren deutschen Patentanmeldung P 38 33 443.7, nach 0. Annen et al., Rev. Prog. Coloration 17, 72-85 (1987) oder M.A. Weaver und L. Shuttleworth, Dyes and Pigments 3, 81-121(1982), erhältlich.The azo dyes I themselves are known per se or according to known methods, for example according to the older German patent application P 38 33 443.7, according to 0. Annen et al., Rev. Prog. Coloration 17, 72-85 (1987) or MA Weaver and L. Shuttleworth, Dyes and Pigments 3, 81-121 (1982).

Der Erfindung lag daher die Aufgabe zugrunde, für den Thermotransferdruck geeignete Rot- und Blaufarbstoffe zu finden, die dem geforderten Eigenschaftsprofil näherkommen als die bisher bekannten Farbstoffe.The invention was therefore based on the object of finding suitable red and blue dyes for thermal transfer printing which come closer to the required property profile than the dyes known hitherto.

Demgemäß wurde die Verwendung der eingangs definierten Azofarbstoffe I für den Thermotransferdruck gefunden.Accordingly, the use of the azo dyes I defined at the outset was found for thermal transfer printing.

Außerdem wurde ein Verfahren zur Übertragung von Azofarbstoffen durch Diffusion von einem Träger auf ein mit Kunststoff beschichtetes Substrat mit Hilfe eines Thermokopfes gefunden, welches dadurch gekennzeichnet ist, daß man hierfür einen Träger verwendet, auf dem sich ein oder mehrere der eingangs definierten Azofarbstoffe I befinden.In addition, a method for transferring azo dyes by diffusion from a support onto a plastic-coated substrate using a thermal head was found, which is characterized in that a support is used for this purpose, on which one or more of the azo dyes I defined at the outset are located.

Weiterhin wurden bevorzugte Ausführungsformen dieses Verfahrens gefunden, welche dadurch gekennzeichnet sind, daß man hierzu Farbstoffe der Formel la

Figure imgb0008
verwendet, in der die Substituenten folgende Bedeutung haben:

  • R1'C1- C8-Alkylgruppen, die Phenyl oder Phenoxy als Substituenten tragen können;
    • eine Cyclohexylgruppe;
    • eine Phenylgruppe, die C1-C4-Alkyl, C1-C4-Alkoxy oder Chlor als Substituenten tragen kann;
    • eine Thienylgruppe;
    • einen Rest der allgemeinen Formel Ila
      Figure imgb0009
      in der p für 0 oder 1 und q für 1 bis 4 stehen und R4' eine C1-C4-Alkyl-, Phenyl- oder Benzylgruppe bezeichnet;
  • R2', R3' C1-C12-Alkyl-, C1-C10-Alkoxy- oder C1-C10-Cyanoalkylgruppen; einen Rest der oben angegebenen Formel Ila;
  • D' den Rest einer Diazokomponente III, die aus der
    • Anilin-, Phenylazoanilin-,
    • Aminothiophen-, Phenylazoaminothiophen-,
    • Aminothiazol-, Phenylazoaminothiazol-,
    • Aminoisothiazol-, Aminobenzisothiazol-,
    • Aminothiadiazol-, Aminoisothiadiazol-,
    • Aminooxazol-, Aminooxadiazol-,
    • Aminodiazol-, Aminotriazol- oder
    • Aminopyrrolreihe
    • stammt.
Furthermore, preferred embodiments of this process have been found, which are characterized in that dyes of the formula Ia
Figure imgb0008
 used, in which the substituents have the following meaning:
  • R 1 ' C 1 - C 8 alkyl groups which can carry phenyl or phenoxy as substituents;
    • a cyclohexyl group;
    • a phenyl group which can carry C 1 -C 4 alkyl, C 1 -C 4 alkoxy or chlorine as substituents;
    • a thienyl group;
    • a radical of the general formula Ila
      Figure imgb0009
       in which p is 0 or 1 and q is 1 to 4 and R 4 ' denotes a C 1 -C 4 alkyl, phenyl or benzyl group;
  • R 2 ' , R 3' C 1 -C 12 alkyl, C 1 -C 10 alkoxy or C 1 -C 10 cyanoalkyl groups; a radical of the formula Ila given above;
  • D 'the rest of a diazo component III, which from the
    • Aniline, phenylazoaniline,
    • Aminothiophene, phenylazoaminothiophene,
    • Aminothiazole, phenylazoaminothiazole,
    • Aminoisothiazole, aminobenzisothiazole,
    • Aminothiadiazole, aminoisothiadiazole,
    • Aminooxazole, aminooxadiazole,
    • Aminodiazole, aminotriazole or
    • Aminopyrrole series
    • comes from.

Bevorzugte Diazokomponenten III sind:

  • - Anilinderivate der allgemeinen Formel Illa
    Figure imgb0010
  • - Phenylazoanilinderivate der allgemeinen Formel Illb
    Figure imgb0011
  • - Aminothiophenderivate der allgemeinen Formel IIIc
    Figure imgb0012
  • - Phenylazoaminothiophenderivate der allgemeinen Formel IIId
    Figure imgb0013
  • - Aminothiazolderivate der allgemeinen Formel Ille
    Figure imgb0014
  • - Phenylazoaminothiazolderivate der allgemeinen Formel Illf
    Figure imgb0015
  • - Aminoisothiazolderivate der allgemeinen Formel IIIg
    Figure imgb0016
  • - Aminobenzisothiazolderivate der allgemeinen Formeln IIIh und IIIi
    Figure imgb0017
  • - Aminothiadiazolderivate der allgemeinen Formel IIIk
    Figure imgb0018
  • - Aminoisothiadiazolderivate der allgemeinen Formel IIII
    Figure imgb0019
  • - Aminopyrrolderivate der allgemeinen Formel IIIm
    Figure imgb0020
Preferred diazo components III are:
  • - Aniline derivatives of the general formula Illa
    Figure imgb0010
  • - Phenylazoaniline derivatives of the general formula Illb
    Figure imgb0011
  • - Aminothiophene derivatives of the general formula IIIc
    Figure imgb0012
  • - Phenylazoaminothiophene derivatives of the general formula IIId
    Figure imgb0013
  • - Aminothiazole derivatives of the general formula Ille
    Figure imgb0014
  • - Phenylazoaminothiazole derivatives of the general formula Illf
    Figure imgb0015
  • - Aminoisothiazole derivatives of the general formula IIIg
    Figure imgb0016
  • - Aminobenzisothiazole derivatives of the general formulas IIIh and IIIi
    Figure imgb0017
  • - Aminothiadiazole derivatives of the general formula IIIk
    Figure imgb0018
  • - Aminoisothiadiazole derivatives of the general formula IIII
    Figure imgb0019
  • - Aminopyrrole derivatives of the general formula IIIm
    Figure imgb0020

Dabei haben die Substituenten folgende Bedeutung:

  • R5, R6, R7 Wasserstoff, Chlor, Brom, Nitro- oder Cyanogruppen;
    • Alkyl-, Alkoxyalkyl-, Alkanoyloxyalkyl- oder Alkoxycarbonylalkylgruppen, die jeweils bis zu 10 C-Atome enthalten können;
    • einen Rest der Formel II;
    • Reste der Formeln
      • -CO-OR15, -CO-NR15R16, -SO-OR15, -SO2-OR15 oder
      • -SO2-NR15R16
        in denen
        • R15 und R16 Alkyl oder Alkoxyalkyl, die jeweils bis zu 10 C-Atome enthalten können, und
        • R16 zusätzlich Wasserstoff bedeuten;
  • R5 weiterhin einen in 3-Stellung durch C1-C8-Alkoxy substituierten Oxadiazolrest;
  • R6 weiterhin Reste der Formeln
    • -CO-R17 oder -CO-OR17
      in denen
      • R17 für Phenyl, das C1-C8-Alkyl als Substituenten tragen kann, steht; einen Rest der allgemeinen Formel IV
        Figure imgb0021
        in der
      • X Cyano, -CO-OR15 oder -CO-NR15R16 bedeutet;
  • R8 Wasserstoff, Chlor, eine Cyano- oder Thiocyanatogruppe, Alkyl-, Alkoxy-, Alkylthio- oder Alkoxyalkylgruppen, die jeweils bis zu 10 C-Atome enthalten können; 2-(C1-C2-Alkoxycarbonyl)ethylthiogruppen;
    • eine 2-(Pyrrolid-1-yl)ethylgruppe;
    • C5-C6-Cycloalkyl- oder -Cycloalkylthiogruppen;
    • eine Phenylgruppe, die C1-C4-Alkyl, C1-C4-Alkoxy, Benzyloxy oder Phenylthio als Substituenten tragen kann,
    • Ar-C1-C4-alkyl-, Ar-C1-C4-alkoxy- oder Ar-C1-C4-alkylthiogruppen;
    • Thienyl- oder Pyridylgruppen, die C1-C4-Alkyl als Substituenten tragen können;
    • einen Rest der Formel II;
    • Reste der Formeln
      • -CO-OR15, -CO-NR15R16, -SO-OR15 oder -SO2-OR15
  • R9 Wasserstoff, Chlor, Brom, eine Nitro-, Cyano-,
    • Thiocyanato- oder Phenylgruppe;
    • Reste der Formeln
      • -CO-OR15 oder -CO-NR15R16
  • R10 Wasserstoff, Chlor, Brom, eine Nitro-, Cyano- oder Formylgruppe;
    • Reste der Formeln
      • -CO-OR15 oder -CO-NR15R16
    • einen Rest der Formel IV
  • R11, R12 Wasserstoff, Chlor, Brom, Nitro- oder Cyanogruppen;
    • C1-C4-Alkyl- oder C1-C4-Alkoxygruppen;
    • Reste der Formeln
      • -CO-OR15 oder -CO-NR15R16
  • R13 Wasserstoff, Chlor, Brom oder C1-C4-Alkylgruppen
  • R14 Wasserstoff oder eine Cyanogruppe;
    • Reste der Formeln
      • -CO-OR15 oder -CO-NR15R16
  • R18 eine Cyano- oder Formamidgruppe;
  • R19 eine Methyl- oder Phenylgruppe;
  • X Wasserstoff, Chlor oder eine Nitrogruppe;
  • Y Wasserstoff oder eine Cyanogruppe.
The substituents have the following meaning:
  • R 5 , R 6 , R 7 are hydrogen, chlorine, bromine, nitro or cyano groups;
    • Alkyl, alkoxyalkyl, alkanoyloxyalkyl or alkoxycarbonylalkyl groups, each of which can contain up to 10 carbon atoms;
    • a radical of formula II;
    • Remains of the formulas
      • -CO-OR 15 , -CO-NR 15 R 16 , -SO-OR 15 , -SO 2 -OR 15 or
      • -SO 2 -NR 15 R 16
        in which
        • R 15 and R 16 are alkyl or alkoxyalkyl, each of which can contain up to 10 carbon atoms, and
        • R 16 additionally represents hydrogen;
  • R 5 is furthermore an oxadiazole radical substituted in the 3-position by C 1 -C 8 alkoxy;
  • R 6 still remains of the formulas
    • -CO-R 17 or -CO-OR 17
      in which
      • R 17 represents phenyl which can carry C 1 -C 8 alkyl as a substituent; a radical of the general formula IV
        Figure imgb0021
         in the
      • X represents cyano, -CO-OR 15 or -CO-NR 15 R 16 ;
  • R 8 is hydrogen, chlorine, a cyano or thiocyanato group, alkyl, alkoxy, alkylthio or alkoxyalkyl groups, each of which may contain up to 10 carbon atoms; 2- (C 1 -C 2 alkoxycarbonyl) ethylthio groups;
    • a 2- (pyrrolid-1-yl) ethyl group;
    • C 5 -C 6 cycloalkyl or cycloalkylthio groups;
    • a phenyl group which can carry C 1 -C 4 alkyl, C 1 -C 4 alkoxy, benzyloxy or phenylthio as substituents,
    • Ar-C 1 -C 4 alkyl, Ar-C 1 -C 4 alkoxy or Ar-C 1 -C 4 alkylthio groups;
    • Thienyl or pyridyl groups which can carry C 1 -C 4 alkyl as substituents;
    • a radical of formula II;
    • Remains of the formulas
      • -CO-OR 15 , -CO-NR 15 R 16 , -SO-OR 15 or -SO 2 -OR 15
  • R 9 is hydrogen, chlorine, bromine, a nitro, cyano,
    • Thiocyanato or phenyl group;
    • Remains of the formulas
      • -CO-OR 15 or -CO-NR 15 R16
  • R 10 is hydrogen, chlorine, bromine, a nitro, cyano or formyl group;
    • Remains of the formulas
      • -CO-OR 15 or -CO-NR 15 R16
    • a radical of formula IV
  • R 11 , R 12 are hydrogen, chlorine, bromine, nitro or cyano groups;
    • C 1 -C 4 alkyl or C 1 -C 4 alkoxy groups;
    • Remains of the formulas
      • -CO-OR 15 or -CO-NR 15 R16
  • R 13 is hydrogen, chlorine, bromine or C 1 -C 4 alkyl groups
  • R 14 is hydrogen or a cyano group;
    • Remains of the formulas
      • -CO-OR 15 or -CO-NR 15 R 16
  • R 18 is a cyano or formamide group;
  • R 19 is a methyl or phenyl group;
  • X is hydrogen, chlorine or a nitro group;
  • Y is hydrogen or a cyano group.

Geeignete Alkylreste Rl, R2, R3, R4, R5, R6, R7, R8, R11, R12, R13, R15 oder R16 sind dabei vor allem Methyl, Ethyl, Propyl, Isopropyl und Butyl, daneben auch Isobutyl, sec.-Butyl und tert.-Butyl.Suitable alkyl radicals Rl , R 2, R 3, R 4, R5, R6, R7, R 8 , R 11 , R12, R 13 , R 15 or R 16 are especially methyl, ethyl, propyl, isopropyl and butyl, in addition also isobutyl, sec-butyl and tert-butyl.

Als Reste R1, R2, R3, R5, R6, R7, R8, R15 oder R16 sind außerdem z.B. Pentyl, Isopentyl, Neopentyl, tert.-Pentyl, Hexyl, 2-Methylpentyl, Heptyl, Octyl, 2-Ethylhexyl und das Isomerengemisch Isooctyl und Cyclohexyl zu nennen.The radicals R 1 , R 2 , R 3 , R 5 , R 6 , R 7 , R 8 , R 15 or R 16 are, for example, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, 2-methylpentyl, heptyl, To name octyl, 2-ethylhexyl and the isomer mixture isooctyl and cyclohexyl.

Reste R1, R2, R3, R5, R6, R7, R8, R15 oder R16 sind weiterhin beispielsweise Nonyl und Decyl sowie ihre Isomerengemische Isononyl und Isodecyl.R 1 , R 2 , R 3 , R 5 , R 6 , R 7 , R 8 , R 15 or R 16 are, for example, nonyl and decyl and their isomer mixtures isononyl and isodecyl.

Daneben eignen sich als Reste R1, R2 oder R3 auch Undecyl, Dodecyl, Tridecyl und sein Isomerengemisch Isotridecyl, Tetradecyl, Pentadecyl, sowie als Reste R2 und R3 zusätzlich Hexadecyl, Heptadecyl, Octadecyl, Nonadecyl und Eicosyl.In addition, undecyl, dodecyl, tridecyl and its isomer mixture isotridecyl, tetradecyl, pentadecyl are also suitable as radicals R 1 , R 2 or R 3 , and also hexadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl as radicals R 2 and R 3 .

Alkylreste R2 oder R3 können auch Phenyl als Substituenten tragen; beispielsweise sind hier zu nennen (dabei bedeutet Ph = Phenyl):

  • -CH2-Ph, -CH(CH3)-Ph, -(CH2)2-Ph,
  • -(CH2)4-CH(CH3)-Ph-3-CH3,
  • -(CH2)3-CH(C4H9)-Ph-3-CH3,
  • -(CH2)6-Ph-4-O-CH3,
  • -CH(C2H5)-(CH2)3-Ph-3-O-C2H5 und
  • -CH(C2H5)-(CH2)3-Ph-3-Cl.
Alkyl radicals R 2 or R 3 can also carry phenyl as substituents; For example, here are to be mentioned (where Ph = phenyl):
  • -CH 2 -Ph, -CH (CH 3 ) -Ph, - (CH 2 ) 2 -Ph,
  • - (CH 2 ) 4 -CH (CH 3 ) -Ph-3-CH 3 ,
  • - (CH 2 ) 3 -CH (C 4 H 9 ) -Ph-3-CH 3 ,
  • - (CH 2 ) 6 -Ph-4-O-CH 3 ,
  • -CH (C 2 H 5 ) - (CH 2 ) 3 -Ph-3-OC 2 H 5 and
  • -CH (C 2 H 5 ) - (CH 2 ) 3 -Ph-3-Cl.

Weiterhin eignen sich z.B. folgende Halogen-, Hydroxy- und Cyanoalkylgruppen als Reste R2 oder R3:

  • -(CH2)5-Cl, -CH(C4H9)-(CH2)3-Cl oder -(CH2)4-CF3;
  • -(CH2)2-CH(CH3)-OH, -(CH2)2-CH(C4H9)-OH oder -CH(C2H5)-(CH2)9-OH;
  • -(CH2)2-CN, -(CH2)3-CN, -CH2-CH(CH3)-CH(C2H5)-CN, -(CH2)6-CH(C2H5)-CN und
  • -(CH2)3-CH(CH3)-(CH2)2-CH(CH3)-CN.
The following halogen, hydroxyl and cyanoalkyl groups are also suitable as R 2 or R 3 :
  • - (CH 2 ) 5 -Cl, -CH (C 4 H 9 ) - (CH 2 ) 3 -Cl or - (CH 2 ) 4 -CF 3 ;
  • - (CH 2 ) 2 -CH (CH 3 ) -OH, - (CH 2 ) 2 -CH (C 4 H 9 ) -OH or -CH (C 2 H 5 ) - (CH 2 ) 9 -OH;
  • - (CH 2 ) 2 -CN, - (CH 2 ) 3 -CN, -CH 2 -CH (CH 3 ) -CH (C 2 H 5 ) -CN, - (CH 2 ) 6 -CH (C 2 H 5 ) -CN and
  • - (CH 2 ) 3 -CH (CH 3 ) - (CH 2 ) 2 -CH (CH 3 ) -CN.

Handelt es sich bei den Resten R1, R2, R3, R5, R6, R7, R15 oder R16 um Alkoxyalkylgruppen der bevorzugten Formel II, so sind geeignete Gruppen W beispielsweise 1,2- und 1,3-Propylen, 1,2-, 1,3-, 1,4- und 2,3-Butylen, Pentamethylen, Hexamethylen und 2-Methylpentamethylen, besonders Ethylen, und Reste R4 vor allem Methyl, Ethyl, Propyl, Butyl sowie Benzyl und Phenyl, die beide Substituenten wie Methyl(oxy), Ethyl(oxy), Propyl(oxy) und Butyl (oxy) tragen können. Besonders bevorzugte Gruppen II sind z .B.:

  • -(CH2)2-0-CH3, -(CH2)2-O-C2H5, -(CH2)2-0-C3H7, -(CH2)2-O-C4H9,
  • -(CH2)2-O-CH2-CH(CH3)-CH3,
  • -(CH2)2-O-Ph, -(CH2)2-O-CH2-Ph,
  • -[(CH2)2-O]2-CH3, -[(CH2)2-O]2-C2H5, -[(CH2)2-O]2-Ph,
  • -[(CH2)2-O]2-Ph-4-O-C4H9,
  • -[(CH2)2-O]3-C4H9, -[(CH2)2-O]3-Ph, -[(CH2)2-O]3-Ph-3-C4H9,
  • -[(CH2)2-O]4-CH3,
  • -(CH2)3-O-(CH2)2-O-CH3, -(CH2)3-O-(CH2)2-O-C2H5,
  • -(CH2)3-O-(CH2)2-O-Ph, -(CH2)3-O-[(CH2)2-O]2-CH3 und
  • -(CH2)3-O-[(CH2)2-O]2-C2H5.
If the radicals R 1 , R 2 , R 3 , R 5 , R 6 , R 7 , R 15 or R 16 are alkoxyalkyl groups of the preferred formula II, suitable groups W are, for example, 1,2- and 1,3 -Propylene, 1,2-, 1,3-, 1,4- and 2,3-butylene, pentamethylene, hexamethylene and 2-methylpentamethylene, especially ethylene, and radicals R 4 especially methyl, ethyl, propyl, butyl and benzyl and phenyl, which can carry both substituents such as methyl (oxy), ethyl (oxy), propyl (oxy) and butyl (oxy). Examples of particularly preferred groups II are:
  • - (CH 2 ) 2 -0-CH 3 , - (CH 2 ) 2 -OC 2 H 5 , - (CH 2 ) 2 -0-C 3 H 7 , - (CH 2 ) 2 -OC 4 H 9 ,
  • - (CH 2 ) 2 -O-CH 2 -CH (CH 3 ) -CH 3 ,
  • - (CH 2 ) 2 -O-Ph, - (CH 2 ) 2 -O-CH 2 -Ph,
  • - [(CH 2 ) 2 -O] 2 -CH 3 , - [(CH 2 ) 2 -O] 2 -C 2 H 5 , - [(CH 2 ) 2 -O] 2 -Ph,
  • - [(CH 2 ) 2 -O] 2 -Ph-4-OC 4 H 9 ,
  • - [(CH 2 ) 2 -O] 3 -C 4 H 9 , - [(CH 2 ) 2 -O] 3 -Ph, - [(CH 2 ) 2 -O] 3 -Ph-3-C 4 H 9 ,
  • - [(CH 2 ) 2 -O] 4 -CH 3 ,
  • - (CH 2 ) 3 -O- (CH 2 ) 2 -O-CH 3 , - (CH 2 ) 3 -O- (CH 2 ) 2 -OC 2 H 5 ,
  • - (CH 2 ) 3 -O- (CH 2 ) 2 -O-Ph, - (CH 2 ) 3 -O - [(CH 2 ) 2 -O] 2 -CH 3 and
  • - (CH 2 ) 3 -O - [(CH 2 ) 2 -O] 2 -C 2 H 5 .

Als weitere bevorzugte Gruppen II sind beispielsweise zu nennen:

  • -(CH2)3-O-CH3, -(CH2)3-O-C2H5, -(CH2)3-O-C3H7, -(CH2)3-O-C4H9,
  • -(CH2)3-O-Ph, -[(CH2)3-O]2-CH3, -[(CH2)3-O-]2-C2H5,
  • -CH2-CH(CH3)-O-CH3, -CH2-CH(CH3)-O-C2H5, -CH2-CH(CH3)-O-C3H7,
  • -CH2-CH(CH3)-O-C4H9, -CH2-CH(CH3)-O-Ph,
  • -(CH2)4-O-CH3, -(CH2)4-O-C2H5, -(CH2)4-O-C4H9,
  • -(CH2)4-O-CH2-CH(C2H5)-C4H9, -(CH2)4-O-Ph,
  • -(CH2)4-O-CH2-Ph-2-O-C2H5, -(CH2)4-O-C6H10-2-C2H5,
  • -[(CH2)4-O]2-CH3, -[(CH2)4-O]2-C2H5, -1(CH2)2-CH(CH3)-0]2-C2H5,
  • -(CH2)5-0-CH3, -(CH2)5-O-C2H5, -(CH2)5-O-C3H7, -(CH2)5-0-Ph,
  • -(CH2)2-CH(C2H5)-O-CH2-Ph-3-O-C4H9, -(CH2)2-CH(C2H5)-O-CH2-Ph-3-Cl,
  • -(CH2)6-O-C4H9, -(CH2)6-O-Ph-4-O-C4H9, -(CH2)3-CH(CH3)-CH2-O-C4H9,
  • -(CH2)3-O-(CH2)4-O-CH3, -(CH2)3-O-(CH2)4-O-C2H5,
  • -(CH2)4-O-(CH2)3-O-CH3 und -(CH2)4-O-(CH2)3-O-C2H5.
Examples of further preferred groups II are:
  • - (CH 2 ) 3 -O-CH 3 , - (CH 2 ) 3 -OC 2 H 5 , - (CH 2 ) 3 -OC 3 H 7 , - (CH 2 ) 3 -OC 4 H 9 ,
  • - (CH 2 ) 3 -O-Ph, - [(CH 2 ) 3 -O] 2 -CH 3 , - [(CH 2 ) 3 -O-] 2 -C 2 H 5 ,
  • -CH 2 -CH (CH 3 ) -O-CH 3 , -CH 2 -CH (CH 3 ) -OC 2 H 5 , -CH 2 -CH (CH 3 ) -OC 3 H 7 ,
  • -CH 2 -CH (CH 3 ) -OC 4 H 9 , -CH 2 -CH (CH 3 ) -O-Ph,
  • - (CH 2 ) 4 -O-CH 3 , - (CH 2 ) 4 -OC 2 H 5 , - (CH 2 ) 4 -OC 4 H 9 ,
  • - (CH 2 ) 4 -O-CH 2 -CH (C 2 H 5 ) -C 4 H 9 , - (CH 2 ) 4 -O-Ph,
  • - (CH 2 ) 4 -O-CH 2 -Ph-2-OC 2 H 5 , - (CH 2 ) 4 -OC 6 H 10 -2-C 2 H 5 ,
  • - [(CH 2 ) 4 -O] 2 -CH 3 , - [(CH 2 ) 4 -O] 2 -C 2 H 5 , -1 (CH 2 ) 2 -CH (CH 3 ) -0] 2 - C 2 H 5 ,
  • - (CH 2 ) 5 -0-CH 3 , - (CH 2 ) 5 -OC 2 H 5 , - (CH 2 ) 5 -OC 3 H 7 , - (CH 2 ) 5 -0-Ph,
  • - (CH 2 ) 2 -CH (C 2 H 5 ) -O-CH 2 -Ph-3-OC 4 H 9 , - (CH 2 ) 2 -CH (C 2 H 5 ) -O-CH 2 -Ph -3-Cl,
  • - (CH 2 ) 6 -OC 4 H 9 , - (CH 2 ) 6 -O-Ph-4-OC 4 H 9 , - (CH 2 ) 3 -CH (CH 3 ) -CH 2 -OC 4 H 9 ,
  • - (CH 2 ) 3 -O- (CH 2 ) 4 -O-CH 3 , - (CH 2 ) 3 -O- (CH 2 ) 4 -OC 2 H 5 ,
  • - (CH 2 ) 4 -O- (CH 2 ) 3 -O-CH 3 and - (CH 2 ) 4 -O- (CH 2 ) 3 -OC 2 H 5 .

Daneben sind z.B. folgende Alkoxyalkylgruppen geeignet:

  • -(CH2)8-O-CH3, -(CH2)8-O-C4H9, -(CH2)8-O-CH2-Ph-3-C2H5,
  • -(CH2)4-CH(Cl)-(CH2)3-O-CH2-Ph-3-CH3 und
  • -(CH2)3-CH(C4H9)-O-CH2-Ph-3-CH3.
The following alkoxyalkyl groups are also suitable:
  • - (CH 2 ) 8 -O-CH 3 , - (CH 2 ) 8 -OC 4 H 9 , - (CH 2 ) 8 -O-CH 2 -Ph-3-C 2 H 5 ,
  • - (CH 2 ) 4 -CH (Cl) - (CH 2 ) 3 -O-CH 2 -Ph-3-CH 3 and
  • - (CH 2 ) 3 -CH (C 4 H 9 ) -O-CH 2 -Ph-3-CH 3 .

Von den oben aufgeführten Alkoxyalkylgruppen sind solche, die bis zu 8 C-Atome enthalten, auch als Reste R8 und solche mit bis zu 12 C-Atomen auch als Reste R15 oder R16 geeignet.Of the alkoxyalkyl groups listed above, those which contain up to 8 carbon atoms are also suitable as radicals R 8 and those with up to 12 carbon atoms are also suitable as radicals R 15 or R 16 .

Als Reste R2, R3, R8, R11 oder R12 bevorzugte Alkoxygruppen sind beispielsweise zu nennen: Methoxy, Ethoxy, Propoxy, Isopropoxy, Butoxy, Isobutoxy und sec.-Butoxy.Preferred alkoxy groups as R 2 , R 3 , R 8 , R 11 or R 12 are, for example: methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy and sec-butoxy.

Reste R8, besonders R2 oder R3 sind weiterhin z.B. Pentyloxy, Isopentyloxy, Neopentyloxy, Hexyloxy, Octyloxy und 2-Ethylhexyloxy.R 8 , in particular R 2 or R 3, are furthermore, for example, pentyloxy, isopentyloxy, neopentyloxy, hexyloxy, octyloxy and 2-ethylhexyloxy.

Als Reste R2 oder R3 eignen sich außerdem beispielsweise Nonyloxy oder Decyloxy, daneben noch Undecyloxy, Dodecyloxy, Tridecyloxy, Tetradecyloxy und Pentadecyloxy.Also suitable as radicals R 2 or R 3 are, for example, nonyloxy or decyloxy, and also undecyloxy, dodecyloxy, tridecyloxy, tetradecyloxy and pentadecyloxy.

Reste R8 können auch Alkylthiogruppen sein wie bevorzugt Methylthio, Ethylthio und 2-Cyanoethylthio, daneben Propylthio, Isopropylthio, Butylthio, Pentylthio, Hexylthio, Heptylthio, Octylthio, 2-Ethylhexylthio, 2-Ethoxycarbonylethylthio und besonders 2-Methoxycarbonylthio.R 8 radicals can also be alkylthio groups, such as preferably methylthio, ethylthio and 2-cyanoethylthio, in addition propylthio, isopropylthio, butylthio, pentylthio, hexylthio, heptylthio, octylthio, 2-ethylhexylthio, 2-ethoxycarbonylethylthio and especially 2-methoxycarbonyl.

Als Reste R2 oder R3 geeignete Alkanoyloxyalkyl-, Alkoxycarbonyloxyalkyl- und Alkoxycarbonylalkylgruppen sind beispielsweise:

  • -(CH2)2-O-CO-CH3,
  • -(CH2)3-O-CO-(CH2)7-CH3,
  • -(CH2)2-O-CO-(CH2)3-Ph-2-O-CH3,
  • -CH(CH2-Ph-3-CH3)-O-CO-C4H9 und
  • -(CH2)4-O-CO-(CH2)4-CH(C2H5)-OH;
  • -(CH2)2-0-CO-O-CH3,
  • -(CH2)3-O-CO-O-(CH2)7-CH3,
  • -CH(C2H5)-CH2-O-CO-O-C4H9,
  • -(CH2)4-O-CO-O-(CH2)2-CH(CH3)-O-Ph-3-CH3 und
  • -(CH2)5-0-CO-0-(CH2)5-CN;
  • -(CH2)2-CO-O-CH3,
  • -(CH2)3-CO-O-C4H9,
  • -(CH2)3-CH(CH3)-CH2-CO-O-C4H9,
  • -(CH2)3-CH(C4H9)-CH2-CO-O-C2H5,
  • -(CH2)2-CO-O-(CH2)5-Ph,
  • -(CH2)4-CO-O-(CH2)4-Ph-4-C4H9,
  • -(CH2)3-CO-0-(CH2)4-0-Ph-3-0-CH3,
  • -(CH2)2-CH(CH2OH)-(CH2)2-CO-O-C2Hs,
  • -CH(C2H5)-CH2-CO-O-(CH2)4-OH und
  • -(CH2)3-CO-O-(CH2)6-CN.
Examples of alkanoyloxyalkyl, alkoxycarbonyloxyalkyl and alkoxycarbonylalkyl groups which are suitable as R 2 or R 3 are:
  • - (CH 2 ) 2 -O-CO-CH 3 ,
  • - (CH 2 ) 3 -O-CO- (CH 2 ) 7 -CH 3 ,
  • - (CH 2 ) 2 -O-CO- (CH 2 ) 3 -Ph-2-O-CH 3 ,
  • -CH (CH 2 -Ph-3-CH 3 ) -O-CO-C 4 H 9 and
  • - (CH 2 ) 4 -O-CO- (CH 2 ) 4 -CH (C 2 H 5 ) -OH;
  • - (CH 2 ) 2 -0-CO-O-CH 3 ,
  • - (CH 2 ) 3 -O-CO-O- (CH 2 ) 7 -CH 3 ,
  • -CH (C 2 H 5 ) -CH 2 -O-CO-OC 4 H 9 ,
  • - (CH 2 ) 4 -O-CO-O- (CH 2 ) 2 -CH (CH 3 ) -O-Ph-3-CH 3 and
  • - (CH 2 ) 5 -0-CO-0- (CH 2 ) 5 -CN;
  • - (CH 2 ) 2 -CO-O-CH 3 ,
  • - (CH 2 ) 3 -CO-OC 4 H 9 ,
  • - (CH 2 ) 3 -CH (CH 3 ) -CH 2 -CO-OC 4 H 9 ,
  • - (CH 2 ) 3 -CH (C 4 H 9 ) -CH 2 -CO-OC 2 H 5 ,
  • - (CH 2 ) 2 -CO-O- (CH 2 ) 5 -Ph,
  • - (CH 2 ) 4 -CO-O- (CH 2 ) 4 -Ph-4-C 4 H 9 ,
  • - (CH 2 ) 3 -CO-0- (CH 2 ) 4 -0-Ph-3-0-CH 3 ,
  • - (CH 2 ) 2 -CH (CH 2 OH) - (CH 2 ) 2 -CO-OC 2 Hs,
  • -CH (C 2 H 5 ) -CH 2 -CO-O- (CH 2 ) 4 -OH and
  • - (CH 2 ) 3 -CO-O- (CH 2 ) 6 -CN.

Phenyl- und Cyclohexylreste, die als Reste R1, R2 oder R3 enthalten sein können, sind beispielsweise folgende:

  • -Ph, -Ph-3-CH3, -Ph-4-(CH2)10-CH3, -Ph-3-(CH2)5-CH(CH3)-CH3, Ph-4-0-C4H9,
  • -Ph-4-(CH2)5-CH(C2H5)-CH3, -Ph-4-0-CH2-Ph und -Ph-4-CI,

sowie im Falle von R1 besonders -Ph-3-S02-N(CH3)-CH3 und
  • -Ph-3-SO2-N((CH2)2-O-CH3)-(CH2)2-O-CH3;
  • -C6H10-4-CH3, -C6H10-4-C10H21, -C6H10-3-O-C4H9,
  • -C6H10-3-O-(CH2)4-CH(C2H5)-CH3 und -C6H10-4-Cl.
Phenyl and cyclohexyl radicals which may be present as R 1 , R 2 or R 3 are, for example, the following:
  • -Ph, -Ph-3-CH 3 , -Ph-4- (CH 2 ) 10 -CH 3 , -Ph-3- (CH 2 ) 5 -CH (CH 3 ) -CH 3 , Ph-4-0 -C 4 H 9 ,
  • -Ph-4- (CH 2 ) 5 -CH (C 2 H 5 ) -CH 3 , -Ph-4-0-CH 2 -Ph and -Ph-4-CI,

and in the case of R 1 especially -Ph-3-S0 2 -N (CH 3 ) -CH 3 and
  • -Ph-3-SO 2 -N ((CH 2 ) 2 -O-CH 3 ) - (CH 2 ) 2 -O-CH 3 ;
  • -C 6 H 10 -4-CH 3 , -C 6 H 10 -4-C 10 H 21 , -C 6 H 10 -3-OC 4 H 9 ,
  • -C 6 H 10 -3-O- (CH 2 ) 4 -CH (C 2 H 5 ) -CH 3 and -C 6 H 10 -4-Cl.

Handelt es sich bei den Resten R5, R6, R7, R8, R9, R10, R11, R12 oder R14 um Gruppierungen der Formeln

  • -CO-OR15 oder -CO-NR15R16, so sind besonders geeignet
  • -CO-O-CH3, -CO-O-C2H5, -CO-O-C3H7, -CO-O-C4H9, -CO-N(CH3)-CH3 und
  • -CO-N(C2H5)-C2H5,

daneben beispielsweise auch
  • -CO-O-C5H11, -CO-O-C6H13,
  • -CO-N(C3H7)-C3H7 und -CO-N(C4H9)-C4H9.
If the radicals R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 or R 14 are groupings of the formulas
  • -CO-OR 15 or -CO-NR 15 R 16 are particularly suitable
  • -CO-O-CH 3 , -CO-OC 2 H 5 , -CO-OC 3 H 7 , -CO-OC 4 H 9 , -CO-N (CH 3 ) -CH 3 and
  • -CO-N (C 2 H 5 ) -C 2 H 5 ,

besides, for example
  • -CO-OC 5 H 11 , -CO-OC 6 H 13 ,
  • -CO-N (C 3H7 ) -C 3 H 7 and -CO-N (C 4 H 9 ) -C 4 H 9 .

Gruppierungen der Formeln -SO-OR15 oder SO2-OR15, die als Reste R5, R6, R7 oder R8 eingesetzt werden können, sind z.B.

  • -SO-O-CH3, -SO-O-C2H5, -SO-O-C3H7,
  • -SO2-O-CH3, -SO2-O-C2H5, -SO2-O-C3H7.
Groupings of the formulas -SO-OR 15 or SO 2 -OR 15 which can be used as radicals R 5 , R 6 , R 7 or R 8 are, for example
  • -SO-O-CH 3 , -SO-OC 2 H 5 , -SO-OC 3 H 7 ,
  • -SO 2 -O-CH 3 , -SO 2 -OC 2 H 5 , -SO 2 -OC 3 H 7 .

Als Reste R5, R6 oder R7 kommen auch Gruppierungen der Formel

  • -SO2-NR15R16 in Betracht, wie besonders
  • -SO2-N(CH3)-CH3, -SO2-N((CH2)2-O-CH3)-(CH2)2-O-CH3, daneben beispielsweise auch
  • -SO2-N(C2H5)-C2H5 und -S02-N(C3H7)-C3H7.
The radicals R 5 , R 6 or R 7 also include groups of the formula
  • -SO 2 -NR 15 R 16 into consideration, how special
  • -SO 2 -N (CH 3 ) -CH 3 , -SO 2 -N ((CH 2 ) 2 -O-CH 3 ) - (CH 2 ) 2 -O-CH 3 , besides for example also
  • -SO 2 -N (C 2 H 5 ) -C 2 H 5 and -S0 2 -N (C 3 H 7 ) -C 3 H 7 .

Reste R6 oder R10 können auch Gruppen der Formel IV sein wie

  • -CH=C(CN)-CN,
  • -CH=C(CN)-CO-O-CH3, -CH=C(CN)-CO-O-C2H5, -CH=C(CN)-CO-O-C3H7,
  • -CH=C(CN)-CO-O-C4H9,
  • -CH=C(CN)-N(CH3)-CH3 und -CH=C(CN)-N(C2H5)-C2H5-
R 6 or R 10 may also be groups of the formula IV, such as
  • -CH = C (CN) -CN,
  • -CH = C (CN) -CO-O-CH 3 , -CH = C (CN) -CO-OC 2 H 5 , -CH = C (CN) -CO-OC 3 H 7 ,
  • -CH = C (CN) -CO-OC 4 H 9 ,
  • -CH = C (CN) -N (CH 3 ) -CH 3 and -CH = C (CN) -N (C 2 H 5 ) -C 2 H 5 -

Von den bereits genannten Resten sind als Reste R1 besonders bevorzugt C1-C8-Alkyl, darunter besonders Methyl und Isopropyl, Cyclohexyl, Phenyl, das auch Methoxy, Sulfonamido oder Chlor als Substituenten tragen kann, und auch Benzyl. Bevorzugte Reste R1 sind weiterhin Thien-3-yl und vor allem Thien-2-yl, Furan-3-yl und besonders Furan-2-yl sowie Pyrid-2-yl, Pyrid-4-yl und besonders Pyrid-3-yl.Of the radicals already mentioned, particularly preferred radicals R 1 are C 1 -C 8 -alkyl, including in particular methyl and isopropyl, cyclohexyl, phenyl, which can also carry methoxy, sulfonamido or chlorine as substituents, and also benzyl. Preferred radicals R 1 are furthermore thien-3-yl and especially thien-2-yl, furan-3-yl and especially furan-2-yl as well as pyrid-2-yl, pyrid-4-yl and especially pyrid-3- yl.

Als Reste R2 oder R3 sind von den genannten Alkylresten solche mit bis zu 12 C-Atomen bevorzugt, darunter besonders Methyl, Ethyl und Propyl, von den genannten Cyanoalkyl- und Alkoxyresten solche mit bis zu 10 C-Atomen. Besonders bevorzugte Reste R2 oder R3 weisen die Formel Ila auf mit Methyl oder Ethyl als Rest R4'. Preferred radicals R 2 or R 3 of the alkyl radicals mentioned are those with up to 12 C atoms, including in particular methyl, ethyl and propyl, of the cyanoalkyl and alkoxy radicals mentioned those with up to 10 C atoms. Particularly preferred radicals R 2 or R 3 have the formula Ila with methyl or ethyl as the radical R4 '.

Von den oben aufgeführten Diazokomponenten D-NH2 sind die folgenden besonders bevorzugt:

  • - Anilinderivate Illa mit der eingangs definierten Bedeutung der Reste R5, R6 und R7
  • - Aminothiophenderivate IIIc mit folgender Bedeutung der Reste R8, R9 und R10:
    • R8 Wasserstoff, Chlor;
      • Alkyl-, auch Alkoxy- oder Alkoxyalkylgruppen, die jeweils bis zu 8 C-Atome enthalten können;
      • eine Phenylgruppe, die C1-C4-Alkyl oder C1-C4-Alkoxy als Substituenten tragen kann, oder eine Benzylgruppe;
      • einen Rest der Formel -CO-OR15;
    • R9 eine Cyanogruppe;
      • Reste der Formeln -CO-OR15 oder auch -CO-NR15R16;
    • R10 eine Cyano-, Nitro- oder Formylgruppe;
      • einen Rest der Formel IV
  • - Aminothiazolderivate Ille mit folgender Bedeutung der Reste R8 und R10:
    • R8 Wasserstoff, Chlor;
      • C1-C8-Alkylgruppen;
      • eine Phenylgruppe, die C1-C4-Alkyl oder C1-C4-Alkoxy als Substituenten tragen kann, oder eine Benzylgruppe;
      • einen Rest der Formel -CO-OR15;
    • R10 eine Cyano-, Nitro- oder Formylgruppe;
      • einen Rest der Formel -CO-OR15
  • - Aminoisothiazolderivate Illg mit folgender Bedeutung der Reste R8 und R9:
    • R8 Chlor;
      • Alkyl-, Alkoxy-, Alkythio- oder Alkoxyalkylgruppen, die jeweils bis zu 8 C-Atome enthalten können;
      • eine Phenylgruppe, die C1-C4-Alkyl oder C1-C4-Alkoxy als Substituenten tragen kann, eine Benzyl- oder Benzyloxygruppe;
    • R9 eine Cyano- oder Nitrogruppe;
      • einen Rest der Formel -CO-OR15
  • - Aminothiadiazolderivate IIIk und Aminoisothiadiazolderivate II mit folgender Bedeutung des Restes R8:
    • R8 Wasserstoff, Chlor, eine Cyano- oder Thiocyanatogruppe;
      • Alkyl-, Alkoxy-, Alkylthio- oder Alkoxyalkylgruppen, die jeweils bis zu 8 C-Atome enthalten können;
      • 2-(C1-C2-Alkoxycarbonyl)ethylthiogruppen;
      • eine Phenylgruppe, die C1-C4-Alkyl oder C1-C4-Alkoxy als Substituenten tragen kann, eine Benzyl- oder Benzyloxygruppe;
      • Reste der Formeln -CO-OR15, -SO-OR15 oder -SO2-OR15.
Of the diazo components D-NH 2 listed above, the following are particularly preferred:
  • - Aniline derivatives Illa with the meaning of the radicals R 5 , R 6 and R 7 defined at the outset
  • - aminothiophene derivatives IIIc with the following meaning of the radicals R 8 , R 9 and R 10 :
    • R8 is hydrogen, chlorine;
      • Alkyl, also alkoxy or alkoxyalkyl groups, each of which can contain up to 8 carbon atoms;
      • a phenyl group which may carry C 1 -C 4 alkyl or C 1 -C 4 alkoxy as a substituent, or a benzyl group;
      • a radical of the formula -CO-OR 15 ;
    • R 9 is a cyano group;
      • Radicals of the formulas -CO-OR 15 or also -CO-NR 15 R 16 ;
    • R 10 is a cyano, nitro or formyl group;
      • a radical of formula IV
  • Aminothiazole derivatives Ille with the following meaning of the radicals R 8 and R 10 :
    • R8 is hydrogen, chlorine;
      • C 1 -C 8 alkyl groups;
      • a phenyl group which may carry C 1 -C 4 alkyl or C 1 -C 4 alkoxy as a substituent, or a benzyl group;
      • a radical of the formula -CO-OR 15 ;
    • R 10 is a cyano, nitro or formyl group;
      • a radical of the formula -CO-OR 15
  • - Aminoisothiazole derivatives Illg with the following meaning of the radicals R 8 and R 9 :
    • R 8 chlorine;
      • Alkyl, alkoxy, alkythio or alkoxyalkyl groups, each of which can contain up to 8 carbon atoms;
      • a phenyl group which may carry C 1 -C 4 alkyl or C 1 -C 4 alkoxy as a substituent, a benzyl or benzyloxy group;
    • R 9 is a cyano or nitro group;
      • a radical of the formula -CO-OR 15
  • Aminothiadiazole derivatives IIIk and aminoisothiadiazole derivatives II with the following meaning of the radical R 8 :
    • R 8 is hydrogen, chlorine, a cyano or thiocyanato group;
      • Alkyl, alkoxy, alkylthio or alkoxyalkyl groups, each of which can contain up to 8 carbon atoms;
      • 2- (C 1 -C 2 alkoxycarbonyl) ethylthio groups;
      • a phenyl group which may carry C 1 -C 4 alkyl or C 1 -C 4 alkoxy as a substituent, a benzyl or benzyloxy group;
      • Residues of the formulas -CO-OR 15 , -SO-OR 15 or -SO 2 -OR 15 .

Die erfindungsgemäß zu verwendenden Farbstoffe zeichnen sich gegenüber den bisher für den Thermotransferdruck eingesetzten Rot- und Blaufarbstoffen mit Kupplungskomponenten auf Anilinbasis durch folgende Eigenschaften aus: leichtere thermische Transferierbarkeit, verbesserte Migrationseigenschaften im Aufnahmemedium bei Raumtemperatur, höhere thermische Stabilität, höhere Lichtechtheit, bessere Resistenz gegen Feuchtigkeit und Chemikalien, bessere Löslichkeit bei der Herstellung der Druckfarbe, höhere Farbstärke sowie leichtere technische Zugänglichkeit.The dyes to be used according to the invention are distinguished from the red and blue dyes with coupling components based on aniline, which have been used for thermal transfer printing to date, by the following properties: easier thermal transferability, improved migration properties in the recording medium at room temperature, higher thermal stability, higher lightfastness, better resistance to moisture and Chemicals, better solubility in the production of the printing ink, higher color strength and easier technical accessibility.

Zudem zeigen die Azofarbstoffe eine deutlich bessere Farbtonreinheit, insbesondere in Farbstoffmischungen, und ergeben verbesserte Schwarz-Drucke.In addition, the azo dyes show a significantly better color purity, especially in dye mixtures, and result in improved black prints.

Die für das erfindungsgemäße Thermotransferdruckverfahren benötigten als Farbstoffgeber fungierenden Transferblätter werden folgendermaßen präpariert: Die Azofarbstoffe werden in einem organischen Lösungsmittel, wie Isobutanol, Methylethylketon, Methylenchlorid, Chlorbenzol, Toluol, Tetrahydrofuran oder deren Mischungen, mit einem oder mehreren Bindemitteln sowie eventuell weiteren Hilfsmitteln wie Trennmitteln oder kristallisationshemmenden Stoffen zu einer Druckfarbe verarbeitet, welche die Farbstoffe vorzugsweise molekular-dispers gelöst enthält. Die Druckfarbe wird anschließend auf einen inerten Träger aufgetragen und getrocknet.The transfer sheets required as dye donors for the thermal transfer printing process according to the invention are prepared as follows: The azo dyes are in an organic solvent such as isobutanol, methyl ethyl ketone, methylene chloride, chlorobenzene, toluene, tetrahydrofuran or mixtures thereof, with one or more binders and possibly other auxiliaries such as release agents or crystallization-inhibiting substances processed into a printing ink, which preferably contains the dyes in a molecularly dispersed solution. The printing ink is then applied to an inert support and dried.

Als Bindemittel für die erfindungsgemäße Verwendung der Azofarbstoffe eignen sich alle in organischen Lösungsmitteln löslichen Materialien, die bekanntermaßen fürden Thermotransferdruck dienen, also z.B. Cellulosederivate wie Methylcellulose, Hydroxypropylcellulose, Celluloseacetat oder Celluloseacetobutyrat, vor allem Ethylcellulose und Ethylhydroxyethylcellulose, Stärke, Alginate, Alkydharze wie Polyvinylalkohol oder Polyvinylpyrrolidon sowie besonders Polyvinylacetat und Polyvinylbutyrat. Daneben kommen Polymere und Copolymere von Acrylaten oder deren Derivaten wie Polyacrylsäure, Polymethylmethacrylat- oder Styrolacrylatcopolymere, Polyesterharze, Polyamidharze, Polyurethanharze oder natürliche Harze wie z.B. Gummi Arabicum in Betracht.Suitable binders for the use of the azo dyes according to the invention are all materials which are soluble in organic solvents and which are known to be used for thermal transfer printing, e.g. Cellulose derivatives such as methyl cellulose, hydroxypropyl cellulose, cellulose acetate or cellulose acetobutyrate, especially ethyl cellulose and ethyl hydroxyethyl cellulose, starch, alginates, alkyd resins such as polyvinyl alcohol or polyvinyl pyrrolidone, and especially polyvinyl acetate and polyvinyl butyrate. In addition there are polymers and copolymers of acrylates or their derivatives such as polyacrylic acid, polymethyl methacrylate or styrene acrylate copolymers, polyester resins, polyamide resins, polyurethane resins or natural resins such as e.g. Gum arabic into consideration.

Häufig empfehlen sich Mischungen dieser Bindemittel, z.B. solche aus Ethylcellulose und Polyvinylbutyrat im Gewichtsverhältnis 2 : 1.Mixtures of these binders are often recommended, e.g. those made of ethyl cellulose and polyvinyl butyrate in a weight ratio of 2: 1.

Das Gewichtsverhältnis von Bindemittel zu Farbstoff beträgt in der Regel 8 : 1 bis 1 : 1, vorzugsweise 5 : 1 bis 2: 1.The weight ratio of binder to dye is usually 8: 1 to 1: 1, preferably 5: 1 to 2: 1.

Als Hilfsmittel werden z.B. Trennmittel auf der Basis von perfluorierten Alkylsulfonamidoalkylestern oder Siliconen, wie sie in der EP-A-227 092 bzw. der EP-A-192 435 beschrieben sind, und besonders organische Additive, welche das Auskristallisieren der Transferfarbstoffe bei Lagerung und Erhitzung des Farbbandes verhindern, beispielsweise Cholesterin oder Vanillin, verwendet.As aids e.g. Release agents based on perfluorinated alkylsulfonamidoalkyl esters or silicones, as described in EP-A-227 092 or EP-A-192 435, and especially organic additives which prevent the transfer dyes from crystallizing out when the ink ribbon is stored and heated, for example cholesterol or vanillin used.

Inerte Trägermaterialien sind beispielsweise Seiden-, Lösch- oder Pergaminpapier sowie Folien aus wärmebeständigen Kunststoffen wie Polyestern, Polyamiden oder Polyimiden, wobei diese Folien auch metallbeschichtet sein können.Inert carrier materials are, for example, tissue paper, blotting paper or glassine paper as well as films made of heat-resistant plastics such as polyesters, polyamides or polyimides, these films also being able to be metal-coated.

Der inerte Träger kann auf der dem Thermokopf zugewandten Seite zusätzlich mit einem Gleitmittel beschichtet werden, um ein Verkleben des Thermokopfes mit dem Trägermaterial zu verhindern. Geeignete Gleitmittel sind beispielsweise Silicone oder Polyurethane, wie sie in der EP-A-216 483 beschrieben sind.The inert carrier can additionally be coated with a lubricant on the side facing the thermal head in order to prevent the thermal head from sticking to the carrier material. Suitable lubricants are, for example, silicones or polyurethanes, as described in EP-A-216 483.

Die Stärke des Farbstoffträgers beträgt im allgemeinen 3 bis 30 µm, bevorzugt 5 bis 10 µm.The thickness of the dye carrier is generally 3 to 30 microns, preferably 5 to 10 microns.

Das zu bedruckende Substrat, z.B. Papier, muß seinerseits mit einem Kunststoff beschichtet sein, welcher den Farbstoff beim Druckvorgang aufnimmt. Vorzugsweise verwendet man hierzu polymere Materialien, deren Glasumwandlungstemperatur Tg zwischen 50 und 100°C beträgt, also z.B. Polycarbonate und Polyester. Näheres hierzu ist den EP-A-227 094, EP-A-133 012, EP-A-133 011, JP-A-199 997/1986 oder JP-A-283 595/1986 zu entnehmen.The substrate to be printed, e.g. Paper, for its part, must be coated with a plastic that absorbs the dye during the printing process. Polymeric materials whose glass transition temperature Tg is between 50 and 100 ° C, i.e. e.g. Polycarbonate and polyester. Further details can be found in EP-A-227 094, EP-A-133 012, EP-A-133 011, JP-A-199 997/1986 or JP-A-283 595/1986.

Für das erfindungsgemäße Verfahren wird ein Thermokopf eingesetzt, der auf Temperaturen bis über 300°C aufheizbar ist, so daß der Farbstofftransfer in einer Zeit von maximal 15 msec erfolgt.For the process according to the invention, a thermal head is used which can be heated to temperatures up to over 300 ° C., so that the dye transfer takes place within a maximum time of 15 msec.

BeispieleExamples

Es wurden zunächst in üblicher Weise Transferblätter (Geber) aus Polyesterfolie von 6 bis 10 µm Stärke hergestellt, die mit einer ca. 5 µm starken Transferschicht aus einem Bindemittel B versehen war, welche jeweils ca. 0,25 g Azofarbstoff I enthielt. Das Gewichtsverhältnis Bindemittel zu Farbstoff betrug jeweils, wenn in den folgenden Tabellen nicht anders angegeben, 4 : 1.Initially, transfer sheets (donors) were produced in the usual way from polyester film of 6 to 10 μm thick, which was provided with an approximately 5 μm thick transfer layer made of a binder B, which each contained approximately 0.25 g of azo dye I. The weight ratio of binder to dye was 4: 1, unless otherwise stated in the tables below.

Das zu bedruckende Substrat (Nehmer) bestand aus Papier von ca. 120 µm Stärke, das mit einer 8 µm dicken Kunststoffschicht beschichtet war (Hitachi Color Video Print Paper).The substrate to be printed (taker) consisted of paper approximately 120 µm thick, which was coated with an 8 µm thick plastic layer (Hitachi Color Video Print Paper).

Geber und Nehmer wurden mit der beschichteten Seite aufeinander gelegt, mit Aluminiumfolie umwickelt und für 2 min zwischen zwei Heizplatten auf eine Temperatur zwischen 70 und 80°C erhitzt. Mit gleichartigen Proben wurde dieser Vorgang dreimal bei jeweils höherer Temperatur zwischen 80 und 120°C wiederholt.The coated side of the encoder and slave was placed on top of one another and wrapped in aluminum foil and heated for two minutes between two hot plates to a temperature between 70 and 80 ° C. With similar samples, this process was repeated three times at a higher temperature between 80 and 120 ° C.

Die hierbei in die Kunststoffschicht des Nehmers diffundierte Farbstoffmenge ist proportional der optischen Dichte, die als Extinktion A photometrisch nach dem jeweiligen Erhitzen auf die oben angegebenen Temperaturen bestimmt wurde.The amount of dye diffused into the plastic layer of the receiver is proportional to the optical density, which was determined as absorbance A photometrically after the respective heating to the temperatures given above.

Die Auftragung des Logarithmus der gemessenen Extinktionswerte Agegen die zugehörige reziproke absolute Temperatur ergibt Geraden, aus deren Steigung die Aktivierungsenergie 4ET für das Transferexperiment zu berechnen ist:

Figure imgb0022
R: allg. GaskonstantePlotting the logarithm of the measured extinction values against the associated reciprocal absolute temperature gives straight lines, from the slope of which the activation energy 4E T for the transfer experiment can be calculated:
Figure imgb0022
 R: general gas constant

Der Auftragung kann zusätzlich die Temperatur T* entnommen werden, bei der die Extinktion den Wert 1 erreicht, d.h., die durchgelassene Lichtintensität ein Zehntel der eingestrahlten Lichtintensität beträgt. Je kleinere Werte die Temperatur T* annimmt, umso besser ist die thermische Transferierbarkeit des untersuchten Farbstoffs.The temperature T * at which the extinction reaches the value 1 can also be taken from the application, ie the transmitted light intensity is one tenth of the incident light intensity. The smaller the temperature T * , the better the thermal transferability of the investigated dye.

In den folgenden Tabellen sind die bezüglich ihres Thermotransferverhaltens untersuchten Azofarbstoffe I mit den zugehörigen Absorptionsmaxima λmax [nm] aufgeführt. Die λmax-Werte wurden in Methylenchlorid oder dem jeweils angegebenen Lösungsmittel gemessen.The azo dyes I examined with regard to their thermal transfer behavior and the associated absorption maxima λ max [nm] are listed in the following tables. The λ max values were measured in methylene chloride or the specified solvent.

Zudem ist das jeweils verwendete Bindemittel B aufgeführt. Dabei bedeutet: EC = Ethylcellulose, PVB = Polyvinylbutyrat, MS = EC:PVB = 2:1, VY = Vylon.In addition, the binder B used in each case is listed. Here means: EC = ethyl cellulose, PVB = polyvinyl butyrate, MS = EC: PVB = 2: 1, VY = Vylon.

Soweit die bereits erwähnten Parameter T* [°C] und ΔEτ [kJ/mol] gemessen wurden, sind die ermittelten Werte ebenfalls angegeben.

Figure imgb0023
Figure imgb0024
Figure imgb0025
Figure imgb0026
Figure imgb0027
Figure imgb0028
Figure imgb0029
Figure imgb0030
Figure imgb0031
Figure imgb0032
Figure imgb0033
Figure imgb0034
Figure imgb0035
Figure imgb0036
Figure imgb0037
Figure imgb0038
Figure imgb0039
Figure imgb0040
Figure imgb0041
Figure imgb0042
 As far as the already mentioned parameters T * [° C] and ΔE τ [kJ / mol] were measured, the determined values are also given.
Figure imgb0023
Figure imgb0024
Figure imgb0025
Figure imgb0026
Figure imgb0027
Figure imgb0028
Figure imgb0029
Figure imgb0030
Figure imgb0031
Figure imgb0032
Figure imgb0033
Figure imgb0034
Figure imgb0035
Figure imgb0036
Figure imgb0037
Figure imgb0038
Figure imgb0039
Figure imgb0040
Figure imgb0041
Figure imgb0042

Claims (3)

1. The use in thermal transfer printing of azo dyes of the formula I
Figure imgb0050
where the substituents have the following meanings:
R1 is hydrogen;
C1-C15-alkyl which may be substituted by phenyl or phenoxy;
cyclohexyl which may be substituted by C1-C5-alkyl, C1-C5-alkoxy or halogen;
phenyl which may be substituted by C1-C5-alkyl, C1-C5-alkoxy, sulfonamido or halogen;
thienyl which may be C1-C5-alkyl- or halogen-substituted, furanyl or pyridyl;
a radical of the formula II
Figure imgb0051
where
W is identical or different C2-C6-alkylene,
n is from 1 to 6 and
R4 is C1-C4-alkyl or a phenyl or benzyl group which may both be substituted by C1-C4-alkyl or C1-C4-alkoxy;
R2 and R3 are each hydrogen; alkyl, alkoxy, alkoxyalkyl, alkanoyloxyalkyl, alkoxycarbonyloxyalkyl, alkoxycarbonylalkyl, haloalkyl, hydroxyalkyl or cyanoalkyl, which may each contain up to 15 carbon atoms and be substituted by phenyl, C1-C4-alkylphenyl, C1-C4-alkoxyphenyl, halophenyl, benzyloxy, C1-C4- alkylbenzyloxy, C1-C4-alkoxybenzyloxy, halobenzyloxy, halogen, hydroxyl or by cyano; cyclohexyl which may be substituted by C1-C15-alkyl, C1-C15-alkoxy or halogen; phenyl which may be substituted by C1-C15-alkyl, C1-C15-alkoxy, benzyloxy or halogen; a radical of the abovementioned formula II; and
D is the radical of a diazo component III
Figure imgb0052
subject to the proviso that azo dyes of the formula
Figure imgb0053
where the subtituents have the following meanings:
a) R' is -H, R" is -CH2-C6H5;
b) R' is -CH3, R" is -C6H4-4-CH3;
c) R' is -C2H5, R" is -C6H4-3-CH3;
d) R' is -CH3, R" is -C6H5,

and of the formula
Figure imgb0054
where R" is hydrogen, methyl or phenyl, shall be excluded.
2. A process for transferring azo dyes by diffusion from a transfer to a plastic-coated substrate with the aid of a thermal printing head, which comprises using for this purpose a transfer on which there is or are situated one or more azo dyes of the formula I as set forth in claim 1.
3. A process as claimed in claim 2, wherein the azo dye used has the formula la
Figure imgb0055
where the substituents have the following meanings:
R1' is C1-C8-alkyl which may be substituted by phenyl or phenoxy;
cyclohexyl;
phenyl which may be substituted by C1-C4-alkyl, C1-C4-alkoxy or chlorine;
thienyl;
a radical of the formula Ila
Figure imgb0056
where p is 0 or 1, q is from 1 to 4, and R4' is C1-C4-alkyl, phenyl or benzyl;
R2' and R3' are each C1-C12-alkyl, C1-C10-alkoxy or C1-C10-cyanoalkyl or a radical of the above- indicated formula Ila; and
D' is the radical of a diazo component III of the aniline, phenylazoaniline, aminothio- phene, phenylazoaminothiophene, aminothiazole, phenylazoaminothiazole, aminoisothiazole, aminobenzisothiazole, aminothiadiazole, aminoisothiadiazole, aminooxazole, aminooxadiazole, aminodiazole, aminotriazole or aminopyrrole series.
EP91101022A 1990-02-08 1991-01-26 Use of azo-dyes for thermal transfer printing Expired - Lifetime EP0441208B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4003780 1990-02-08
DE4003780A DE4003780A1 (en) 1990-02-08 1990-02-08 USE OF AZO DYES FOR THERMAL TRANSFER PRINTING

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Publication Number Publication Date
EP0441208A1 EP0441208A1 (en) 1991-08-14
EP0441208B1 true EP0441208B1 (en) 1994-05-04

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EP91101022A Expired - Lifetime EP0441208B1 (en) 1990-02-08 1991-01-26 Use of azo-dyes for thermal transfer printing

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US (2) US5158928A (en)
EP (1) EP0441208B1 (en)
JP (1) JP3001991B2 (en)
DE (2) DE4003780A1 (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4112654A1 (en) * 1991-04-18 1992-10-22 Basf Ag METHOD FOR TRANSMITTING METHINE DYES
DE4426023A1 (en) * 1994-07-22 1996-01-25 Basf Ag Azo dyes with a coupling component from the aminothiazole series
DE19611351A1 (en) * 1996-03-22 1997-09-25 Basf Ag Dye mixtures containing thienyl and / or thiazole azo dyes
CN1531724A (en) * 2001-03-28 2004-09-22 Optical data carrier containing heterocyclic azy dye as light-absorbing compound in information layer
US20080081766A1 (en) * 2006-09-29 2008-04-03 Fujifilm Corporation Image-forming method using heat-sensitive transfer system
EP1974948A3 (en) 2007-03-29 2012-02-08 FUJIFILM Corporation Image-forming method using heat-sensitive transfer system
JP2008265319A (en) * 2007-03-29 2008-11-06 Fujifilm Corp Thermal transfer ink sheet and image formation method
US8258300B2 (en) * 2008-09-29 2012-09-04 King Abdulaziz University Azo dyes

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0432705A1 (en) * 1989-12-11 1991-06-19 Eastman Kodak Company Thermal print element comprising a magenta 3-aryl-2-arylazo-5-aminothiazole or aminothiophene dye stabilized with a cyan indoaniline dye

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60239291A (en) * 1984-05-11 1985-11-28 Mitsubishi Chem Ind Ltd Coloring matter for thermal recording
GB8504518D0 (en) * 1985-02-21 1985-03-27 Ici Plc Thermal transfer dyesheet
DE3638756A1 (en) * 1986-11-13 1988-05-26 Basf Ag METHOD FOR TRANSMITTING DYES
DE3928243A1 (en) * 1989-08-26 1991-02-28 Basf Ag MEROCYANINE-TYPE THIAZOLIC DYES AND A METHOD FOR THERMAL TRANSFER OF THESE DYES

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0432705A1 (en) * 1989-12-11 1991-06-19 Eastman Kodak Company Thermal print element comprising a magenta 3-aryl-2-arylazo-5-aminothiazole or aminothiophene dye stabilized with a cyan indoaniline dye

Also Published As

Publication number Publication date
USRE34877E (en) 1995-03-14
JP3001991B2 (en) 2000-01-24
EP0441208A1 (en) 1991-08-14
DE4003780A1 (en) 1991-08-14
DE59101521D1 (en) 1994-06-09
US5158928A (en) 1992-10-27
JPH04357088A (en) 1992-12-10

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