EP0248405B1 - Heat-sensitive registration material - Google Patents

Heat-sensitive registration material Download PDF

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Publication number
EP0248405B1
EP0248405B1 EP87107971A EP87107971A EP0248405B1 EP 0248405 B1 EP0248405 B1 EP 0248405B1 EP 87107971 A EP87107971 A EP 87107971A EP 87107971 A EP87107971 A EP 87107971A EP 0248405 B1 EP0248405 B1 EP 0248405B1
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EP
European Patent Office
Prior art keywords
sensitive recording
recording material
heat sensitive
material according
iron
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
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EP87107971A
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German (de)
French (fr)
Other versions
EP0248405A3 (en
EP0248405A2 (en
Inventor
Toshimi Central Research Laboratory Satake
Toshiaki Central Research Laboratory Minami
Tomoaki Central Research Laboratory Nagai
Fumio Central Research Laboratory Fujimura
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Jujo Paper Co Ltd
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Jujo Paper Co Ltd
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Publication date
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Publication of EP0248405A3 publication Critical patent/EP0248405A3/en
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Publication of EP0248405B1 publication Critical patent/EP0248405B1/en
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Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
    • G03C1/00—Photosensitive materials
    • G03C1/494—Silver salt compositions other than silver halide emulsions; Photothermographic systems ; Thermographic systems using noble metal compounds
    • G03C1/498—Photothermographic systems, e.g. dry silver
    • G03C1/4989—Photothermographic systems, e.g. dry silver characterised by a thermal imaging step, with or without exposure to light, e.g. with a thermal head, using a laser
    • 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
    • B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
    • B41M5/32—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers one component being a heavy metal compound, e.g. lead or iron
    • 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
    • B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
    • B41M5/333—Colour developing components therefor, e.g. acidic compounds
    • B41M5/3333—Non-macromolecular compounds
    • B41M5/3335—Compounds containing phenolic or carboxylic acid groups or metal salts thereof
    • 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
    • B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
    • B41M5/333—Colour developing components therefor, e.g. acidic compounds
    • B41M5/3333—Non-macromolecular compounds
    • B41M5/3335—Compounds containing phenolic or carboxylic acid groups or metal salts thereof
    • B41M5/3336—Sulfur compounds, e.g. sulfones, sulfides, sulfonamides

Definitions

  • the invention relates to a heat-sensitive recording material which is superior in its dispersibility, its image contrast, its resistance to oils and solvents and its optical readability in the near ultra-red range.
  • Heat-sensitive recording sheets in which a color reaction between a colorless or slightly colored chromogenic substance and a phenolic substance or an organic acid takes place due to the action of heat or heat include in Japanese Patent Publications No. 4160/1968 and 14039/1970 and in JP-OLS No. 27736/1973. They are used in many different ways in practice.
  • a heat-sensitive recording sheet is generally prepared by applying a coating composition to the surface of a support such as paper, film, etc., which is prepared by finely grinding and dispersing a colorless chromogenic substance and a color developing material, mixing the dispersions obtained with one another and adding a binder, Filler, sensitizer, lubricant and other auxiliary has been obtained. When exposed to heat or heat, the coating immediately undergoes a chemical reaction with color formation.
  • heat-sensitive recording sheets include use in medical and technical recording devices, terminal printers for computers and information systems, printers for facsimile or copying machines and electronic calculating machines, ticket machines and the like.
  • the heat-sensitive recording system has been developed and has found a variety of practical uses, which have been aimed at increasing the recording speed and improving the image quality, that is, increasing the image resolution. It is desirable to get by with less thermal energy on the thermal head, so the heat-sensitive recording sheet should have sufficient color-forming sensitivity for bright chromogenic recordings with little heat input from the thermal head.
  • a heat sensitive recording sheet Because of its function as an information recording paper, it is inevitable that a heat sensitive recording sheet comes into contact with human hands. Since oily materials such as hair oil, skin secretions, and solvents such as alcohol, acetone, etc. often stick to the hands and fingers of workers, a heat-sensitive recording sheet is often soiled by such substances. In general, a heat-sensitive recording sheet is not sufficiently stable against such oily materials and solvents as alcohols, acetones, etc. Therefore, the phenomenon that the image density of the soiled part decreases or the image is faded is observed, and that the stain causes discoloration of the background or Color formation.
  • the heat sensitive recording sheets containing a leuco dye and a coloring agent are used as thermal labels in the field of POS systems.
  • the color development occurs in the visible range, so that the color development cannot be read by the bar code scanner when a semiconducting laser beam is used in the near ultra-red range.
  • Japanese patent publication 8787/1957 describes the combined use of iron stearate as an electron acceptor with tannic acid or gallic acid as an electron donor
  • Japanese Patent publications 6485/1959 describe the combined use of an electron acceptor such as silver stearate, iron stearate, gold stearate, copper stearate or mercury behenate with an electron donor such as methyl gallate, ethyl gallate, propyl gallate, butyl gallate or dodecyl gallate.
  • JP-OLS No. 89193/1984 describes a combination of a color development system using a leuco dye and a color developing agent and a color development system using a metal compound consisting of an iron salt of a higher fatty acid and a polyhydric phenol.
  • this combination is disadvantageous because it requires a protective layer to cover the color.
  • solvents, such as alcohol penetrate through pinholes in the protective layer, resulting in discoloration due to the reaction between a leuco dye and a color developing agent contained in the color developing layer by the penetrated solvents.
  • the iron salt of a higher fatty acid with 16 to 35 carbon atoms has the disadvantages that fine foams are formed, the viscosity is increased and many, when grinding and dispersing by means of a grinding device such as a ball mill, attritor, sand grinder, etc., down to a particle size of a few micrometers Coagulates arise.
  • the above iron salts of the higher fatty acids as such are also weakly colored, so the background of a heat sensitive material is that Dispersion of the coating composition and the application of this coating composition colored, which leads to an inferior image contrast as a disadvantage.
  • the invention has for its object to provide a heat-sensitive recording material which is superior in dispersion, image contrast, oil resistance, solvent resistance and optical readability in the near ultraviolet range.
  • the recording sheet has a color development layer applied to a support which contains a metal double salt of a higher fatty acid having 16 to 35 carbon atoms as an electron acceptor and a suitable electron donor.
  • the type of electron donor is not particularly limited, but the preferred electron donor is selected from at least one of the following connecting groups or compounds: Polyvalent aromatic hydroxyl compounds diphenylcarbazide, diphenylcarbazone, hexamethylenetetramine, spirobenzopyran and 1-formyl-4-phenylsemicarbazide.
  • the heat-sensitive recording material according to the invention is produced by applying the coating composition, which contains the combination of a previous electron donor and an above electron acceptor, to a base support.
  • the metal double salts of higher fatty acids according to the invention are double salts which have at least two types of metal atoms per molecule. They therefore differ significantly in their physicochemical properties from the previous metal salts of higher fatty acids, which only contain one type of metal atom in their molecule.
  • These metal double salts of the higher fatty acids are prepared by reacting at least two inorganic metal salts with an alkali metal salt or ammonium salt of the selected higher fatty acid.
  • the type and the mixing ratio of the metal atoms of the at least two inorganic metal salts can be easily adjusted and controlled in this way.
  • the zinc-iron double salt of behenic acid with iron and zinc in a ratio of 2: 1 can be prepared by mixing sodium behenate with an aqueous solution of ferrichloride and zinc chloride in one Molar ratio of 2: 1 is implemented.
  • Suitable metals for the double salt formation of the higher fatty acids are polyvalent metals, for example iron, zinc, calcium, magnesium, aluminum, barium, lead, manganese, tin, nickel, cobalt, copper, silver, mercury, etc .; preferably iron, zinc, calcium, aluminum, magnesium and silver.
  • Suitable fatty acids for the double salt formation are saturated and / or unsaturated aliphatic fatty acids with 16 to 35 carbon atoms.
  • the electron donors of the invention which are used with the metal double salt of a higher fatty acid, are preferably polyvalent aromatic hydroxyl compounds, dipenyl carbazide, diphenyl carbazone, hexamethylenetetramine, spirobenzopyran and 1-formyl-4-phenylsemicarbazide; most preferred are the polyvalent aromatic hydroxyl compounds of the general formula (I): in which R is an alkyl group with 18 to 35 carbon atoms, means (wherein R1 represents an alkyl group having 18 to 35 carbon atoms); n represents an integer from 2 to 3; and "-X-" for -CH2-, -CO2-, -CO-, -O-, -CONH-, (wherein R ⁇ is an alkyl group having 5 to 30 carbon atoms), -SO2 -, -SO3 - or - SO2NH - is.
  • R is an alkyl group with 18 to 35 carbon atoms, means (wherein R1 represents an al
  • Such metal double salts of higher fatty acids can be used as an electron acceptor alone or in a mixture.
  • polyvalent aromatic hydroxyl compounds according to the invention as an electron donor is not subject to any particular restrictions, for example a compound of the following formulas can be used, wherein R is an alkyl group with 18 to 35 carbon atoms and R ⁇ is an alkyl group with 5 to 30 carbon atoms,
  • the coating composition When preparing the coating composition by dispersing this polyvalent phenol derivative in an aqueous or solvent-free binder, it is necessary to avoid a reaction of this phenol derivative with an electron donor and to increase the solvent and dispersion stability of this phenol. It is desirable that the substituent other than the color developing group has a large number of carbon atoms, namely 18 to 35, 2 to 3 OH groups are present, and these OH groups are close to each other.
  • This polyhydric phenol, etc. is used alone or in a mixture as needed.
  • Suitable color developing agents when using a colorless dye are: bisphenol A, p, p ⁇ - (1-methyl-normal-hexylidene) diphenol, p-tertiary-butylphenol, p-phenylphenol, p-hydroxybenzoic acid ester, novolak phenolic resin, 4-hydroxy 1-methylsulfonylbenzene, 4-hydroxy-1-butyloxysulfonylbenzene, etc.
  • the electron donor of the invention is particularly superior.
  • the additives which can be used according to the invention are, for example, the following: Anti-mottling agents (e.g. fatty acid amide, ethylene bisamide, montan wax); Sensitizer (e.g. dibenzyl therephthalate, benzyl p-benzyloxybenzoate, di-p-tolyl carbonate, p-benzyl biphenyl); and stabilizer (for example, metal salt of a phthalic acid monoester, metal salt of p-tert, butylbenzoic acid, metal salt of nitrobenzoic acid).
  • Anti-mottling agents e.g. fatty acid amide, ethylene bisamide, montan wax
  • Sensitizer e.g. dibenzyl therephthalate, benzyl p-benzyloxybenzoate, di-p-tolyl carbonate, p-benzyl biphenyl
  • stabilizer for example, metal salt of a phthalic acid monoester, metal salt of p-tert
  • Binders according to the invention are e.g. B. fully saponified polyvinyl alcohol, degree of polymerization: 200-1900, partially saponified polyvinyl alcohol, carboxylated polyvinyl alcohol, amide-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, butyral-modified polyvinyl alcohol, other modified polyvinyl alcohols, hydroxyethyl cellulose, Methyl cellulose, carboxymethyl cellulose, styrene-maleic anhydride copolymers, styrene-butadiene copolymers, cellulose derivatives such as ethyl cellulose and acetyl cellulose, polyvinyl chloride, polyvinyl acetate, polyacrylamide, polyacrylic acid ester, polyvinyl butyral, polystyrene, copolymers of the above compounds, polyamide resin, cylon resin, silicone resin, polyamide resin, silicone resin . These high molecular
  • the type and amount of the metal double salt of the higher fatty acid, the polyhydric phenol derivative, the binder, the other additives, which are determined depending on the desired effect and suitability for recording purposes, are not particularly limited. In general, it is advantageous to use 1 to 6 parts by weight of the electron donor and 2 to 15 parts by weight of filler, based on 1 to 9 parts of the metal double salt of the higher fatty acid, and 0.5 to 4 parts by weight of binder , based on the total solids content.
  • the heat-sensitive material according to the invention is produced by applying the coating composition to a base material such as paper, synthetic paper, film, etc.
  • the above-mentioned metal double salt of a higher fatty acid, the above electron donor, optionally the organic color developing agent and the basic, colorless chromogenic dye are by means of a grinding device such as a ball mill, attritor, sanding machine, etc., or by means of a suitable emulsifying machine to a particle size of several microns or grind smaller. Various additives are added to this.
  • the additives which can be used according to the invention are, for example, the following: Inorganic or organic fillers such as silicon dioxide, calcium carbonate, kaolin, baked kaolin, diatomaceous earth, talc, titanium dioxide, aluminum hydroxide, etc .; Release agents such as metal salts of fatty acids; Lubricants such as waxes; UV absorbers of the benzophenone and triazole series; waterproofing agents such as glyoxal, etc., dispersants; Antifoam and so on.
  • the metal salt of a higher fatty acid has both hydrophilic groups and hydrophobic groups, and therefore has the properties of a surfactant. Therefore, when grinding and dispersing by means of a grinding device such as a ball mill, attritor, sand grinder, etc. down to a particle size of a few microns and less, it has the disadvantages that foams are formed, the viscosity is increased and many coagulates are formed. Surprisingly, this is not the case when using the double salts according to the invention. Perhaps the different metals cause subtle differences in the surface-active properties, so that the dispersibility is increased.
  • the superior optical readability of the heat-sensitive recording sheet of the present invention in the near-red range may have the following cause.
  • the color is formed by the heat-melt reaction
  • the color development area results in a recordable image in the visible range and in the near ultra-red range (wavelength range from 700 to 1000 nm).
  • the cause of the superior resistance of the recording image to oil and solvent is an irreversible color-forming reaction which occurs when it is melted and which occurs between a metal double salt of the higher fatty acid as an electron acceptor and a polyvalent phenol derivative, etc. as an electron donor.
  • the heat-melt color formation reaction forms a very stable complex which is not dissolved by adhering hair oil, oil materials and solvents such as alcohol.
  • the metal double salt of higher fatty acids according to the invention has 16-35 carbon atoms per. Molecule has, and therefore that Solubility in the hair oil, the oil materials and the organic solvent such as alcohol, etc. is very small, so that when it comes into contact with the contaminant, there is no chemical reaction between the metal double salt of higher fatty acids and the electron donor, such as a polyhydric phenol, etc. The better image contrast is also surprising.
  • the metal salts of higher fatty acids have different colors, from colorless to clearly colored, depending on the properties of the metals.
  • the iron salt of higher fatty acids is pale yellow, whereas the zinc salt of higher fatty acids is colorless.
  • the iron-zinc double salt of a fatty acid, in which iron and zinc are present in one molecule, is only very weakly colored, which leads to only a very slight coloration of the heat-sensitive recording material after application of the coating material obtained by dispersing the double salt. In this way, a suitable combination of the metals can be used to produce a heat-sensitive recording material with a very lightly colored background.
  • This coating composition was applied in a coating amount of 6.0 g / m2 on a base paper with a weight of 50 g / m2, dried and supercalendered to achieve a smoothness of 200-600 seconds.
  • a heat sensitive recording sheet was obtained.
  • the solutions of the above compositions were individually milled in a attritor to a particle size of 3 microns. The solutions were then mixed together in the same ratio as in the examples, a heat-sensitive coating composition being obtained.
  • This coating composition was applied in a coating amount of 6.0 g / m2 on a base paper with a weight of 50 g / m2, dried and supercalendered to achieve a smoothness of 200-600 seconds.
  • a heat sensitive recording sheet was obtained.
  • the recording sheets obtained in the examples and comparative examples were tested for the qualities given in Tables 1 and 2, where the results are also summarized.

Description

Die Erfingung betrifft ein wärmeempfindliches Aufzeichnungsmaterial, das überlegen in seiner Dispergierbarkeit, seinem Bildkontrast, seiner Beständigkeit gegenüber Ölen und Lösungsmitteln und seiner optischen Lesbarkeit im nahen ultraroten Bereich ist.The invention relates to a heat-sensitive recording material which is superior in its dispersibility, its image contrast, its resistance to oils and solvents and its optical readability in the near ultra-red range.

(Stand der Technik)(State of the art)

Wärmeempfindliche Aufzeichnungsblätter, bei denen durch Wärme- oder Hitzeeinwirkung eine Farbreaktion zwischen einem farblosen oder schwachfarbigen chromogenen Stoff und einer phenolischen Substanz oder einer organischen Säure stattfindet, sind u.a. in den japanischen Patentpublikationen Nr. 4160/1968 und 14039/1970 und in JP-OLS Nr. 27736/1973 beschrieben. Sie finden vielfältige Anwendung in der Praxis.Heat-sensitive recording sheets in which a color reaction between a colorless or slightly colored chromogenic substance and a phenolic substance or an organic acid takes place due to the action of heat or heat include in Japanese Patent Publications No. 4160/1968 and 14039/1970 and in JP-OLS No. 27736/1973. They are used in many different ways in practice.

Ein wärmeempfindliches Aufzeichnungsblatt wird im allgemeinen hergestellt, indem man auf die Oberflache eines Trägers wie Papier, Film usw. eine Beschichtungsmasse aufbringt, die durch Feinvermahlen und Dispergieren eines farblosen chromogenen Stoffes und eines Farbentwicklungsmaterials, Vermischen der erhaltenen Dispersionen miteinander und Zugeben eines Bindemittels, Füllstoffs, Sensibilisierungsmittels, Gleitmittels und anderer Hilfsmittel erhalten worden ist.
Bei Wärme- oder Hitzeeinwirkung erfolgt in der Beschichtung augenblicklich eine chemische Umsetzung unter Farbbildung.A heat-sensitive recording sheet is generally prepared by applying a coating composition to the surface of a support such as paper, film, etc., which is prepared by finely grinding and dispersing a colorless chromogenic substance and a color developing material, mixing the dispersions obtained with one another and adding a binder, Filler, sensitizer, lubricant and other auxiliary has been obtained.
When exposed to heat or heat, the coating immediately undergoes a chemical reaction with color formation.

Die vielfältige praktische Verwendung dieser wärmeempfindlichen Aufzeichnungsblätter umfaßt die Anwendung bei medizinischen und technischen Aufzeichnungsgeräten, Terminaldruckern von Computern und Informationssystemen, Druckern von Faksimilier- oder Kopiermaschinen und elektronischen Rechenmaschinen, Fahrscheinautomaten und dgl.The various practical uses of these heat-sensitive recording sheets include use in medical and technical recording devices, terminal printers for computers and information systems, printers for facsimile or copying machines and electronic calculating machines, ticket machines and the like.

In den letzten Jahren ist das wärmeempfindliche Aufzeichnungssystem weiter entwickelt worden, und es hat vielfältige praktische Verwendung gefunden, wobei eine erhöhte Aufzeichnungsgeschwindigkeit und die Verbesserung der Bildqualität, d. h. die Erhöhung der Bildauflösung, angestrebt wurden. Es ist wünschenswert, mit geringerer Wärmeenergie am Thermokopf auszukommen, deshalb soll das wärmeempfindliche Aufzeichnungsblatt eine ausreichende farbbildende Empfindlichkeit für helle chromogene Aufzeichnungen bei geringer Wärmezufuhr durch den Thermokopf haben.In recent years, the heat-sensitive recording system has been developed and has found a variety of practical uses, which have been aimed at increasing the recording speed and improving the image quality, that is, increasing the image resolution. It is desirable to get by with less thermal energy on the thermal head, so the heat-sensitive recording sheet should have sufficient color-forming sensitivity for bright chromogenic recordings with little heat input from the thermal head.

Aufgrund seiner Funktion, als Informations-Aufzeichnungspapier zu dienen, ist es unvermeidlich, daß ein wärmeempfindliches Aufzeichnungblatt mit den Händen von Menschen in Berührung kommt. Da ölige Materialien, wie Haaröl, Hautsekret, und Lösungsmittel, wie Alkohol, Aceton usw., öfters an den Händen und Fingern von Arbeitern kleben, wird ein wärmeempfindliches Aufzeichnungsblatt häufig durch solche Substanzen verschmutzt. Im allgemeinen ist ein wärmeempfindliches Aufzeichnungsblatt nicht genügend stabil gegenüber solchen öligen Materialien und Lösungsmitteln, wie Alkoholen, Acetonen usw. Man beobachtet daher das Phänomen, daß die Bilddichte des verschmutzten Teils abnimmt oder das Bild verlöscht, und daß die Verschmutzung eine Verfärbung des Hintergrundes oder eine Farbbildung hervorruft.Because of its function as an information recording paper, it is inevitable that a heat sensitive recording sheet comes into contact with human hands. Since oily materials such as hair oil, skin secretions, and solvents such as alcohol, acetone, etc. often stick to the hands and fingers of workers, a heat-sensitive recording sheet is often soiled by such substances. In general, a heat-sensitive recording sheet is not sufficiently stable against such oily materials and solvents as alcohols, acetones, etc. Therefore, the phenomenon that the image density of the soiled part decreases or the image is faded is observed, and that the stain causes discoloration of the background or Color formation.

Die Ursache für die Abnahme der Bilddichte und die Verschlechterung des Hintergrundes ist unklar, man vermutet aber, daß obige Substanzen die Farbentwicklungsschicht oder das farbbildende Reaktionsprodukt unstabil machen, so daß das entwickelt Bild verlöscht, oder die farbbildende Reaktion wegen des Lösungsmittels zwischen dem Farbstoff und dem Farbentwicklungsmittel stattfindet, und sich der Hintergrund dadurch färbt.The cause of the decrease in the image density and the deterioration of the background is unclear, but it is believed that the above substances make the color developing layer or the color-forming reaction product unstable, so that the developed image is extinguished, or the color-forming reaction due to the solvent between the dye and the Color developing agent takes place, and the background thereby colors.

Zur Verbesserung des Beständigkeit gegenüber Ölen und Lösungsmitteln wurden Verfahren vorgeschlagen, bei denen ein Leukofarbstoff, ein organisches Lösungsmittel und ein Metallsalz einer organischen Säure in der Farbentwicklungsschicht verwendet werden, und eine Schutzschicht auf der Farbentwicklungsschicht gebildet wird. Aber diese Verfahren ergeben noch keine befriedigenden Ergebnisse.In order to improve the resistance to oils and solvents, methods have been proposed in which a leuco dye, an organic solvent and a metal salt of an organic acid are used in the color development layer and a protective layer is formed on the color development layer. But these methods have not yet given satisfactory results.

Die wärmeempfindlichen Aufzeichnungsblätter, die einen Leukofarbstoff und ein Färbungsmittel enthalten, werden auf dem Gebiet der POS-Systeme als thermische Zettel angewandt. Dabei tritt die Farbentwicklung im sichtbaren Bereich auf, so daß die Farbentwicklung bei der Verwendung eines halbleitenden Laserstrahls im nahen ultraroten Bereich vom Strichcode-Abtaster nicht lesbar ist.The heat sensitive recording sheets containing a leuco dye and a coloring agent are used as thermal labels in the field of POS systems. The color development occurs in the visible range, so that the color development cannot be read by the bar code scanner when a semiconducting laser beam is used in the near ultra-red range.

Im Gegensatz zum obigen wärmempfindlichen Farbentwicklungssystem, das farblose Farbstoffe verwendet, ist auf ein wärmeempfindliches Farbentwicklungssystem bekannt, das Metallverbindungen verwendet. Beispielsweise ist in der japanischen Patentpublikation 8787/1957 die kombinierte Verwendung von Eisenstearat als Elektronenakzeptor mit Tanninsäure oder Gallussäure als Elektronendonator beschrieben, und in der japanischen Patenpublikationen 6485/1959 ist die kombinierte Verwendung von einem Elektronenakzeptor wie Silberstearat, Eisenstearat, Goldstearat, Kupferstearat oder Quecksilberbehenat mit einem Elektronendonator wie Methylgallat, Athylgallat, Propylgallat, Butylgallat oder Dodecylgallat beschrieben.In contrast to the above heat-sensitive color development system that uses colorless dyes, a heat-sensitive color development system that uses metal compounds is known. For example, Japanese patent publication 8787/1957 describes the combined use of iron stearate as an electron acceptor with tannic acid or gallic acid as an electron donor, and in Japanese Patent publications 6485/1959 describe the combined use of an electron acceptor such as silver stearate, iron stearate, gold stearate, copper stearate or mercury behenate with an electron donor such as methyl gallate, ethyl gallate, propyl gallate, butyl gallate or dodecyl gallate.

Diese wärmeempfindlichen Aufzeichnungsblätter haben aber die Nachteile, daß bei Berührung des Blattes mit dem Thermokopf das Blatt und/oder Rückstände des Blattes am Thermokopf haften, die Bilddichte unterlegen, die Farbe grünlich ist, der Weißgrad des Hintergrundes verschlechtert wird, die Beständigkeit gegenüber Lösungsmitteln wie Alkoholen unterlegen ist, und die Farbentwicklungsschicht ausfließt.However, these heat-sensitive recording sheets have the disadvantages that when the sheet comes into contact with the thermal head, the sheet and / or residues of the sheet adhere to the thermal head, the image density is inferior, the color is greenish, the whiteness of the background is deteriorated, and the resistance to solvents such as alcohols is inferior, and the color development layer flows out.

Weiter ist in der JP-OLS Nr. 89193/1984 eine Kombination aus einem Farbentwicklungssystem, das einen Leukofarbstoff und ein Farbentwicklungsmittel verwendet, und einem Farbentwicklungssystem, das eine Metallverbindung verwendet, die aus einem Eisensalz einer höheren Fettsäure und einem mehrwertigen Phenol besteht, beschrieben. Diese Kombination ist jedoch nachteilig, weil sie eine Schutzschicht zum Bedecken der Färbung benötigt. Weiter hat sie den Nachteil, daß Lösungsmittel, wie Alokohol, durch Nadellöcher der Schutzschicht penetrieren, was zu Verfärbungen aufgrund der Reaktion zwischen einem Leukofarbstoff und einem Farbentwicklungsmittel, die in der Farbentwicklungsschicht enthalten sind, durch die penetrierten Lösungsmittel führt.Further, JP-OLS No. 89193/1984 describes a combination of a color development system using a leuco dye and a color developing agent and a color development system using a metal compound consisting of an iron salt of a higher fatty acid and a polyhydric phenol. However, this combination is disadvantageous because it requires a protective layer to cover the color. It also has the disadvantage that solvents, such as alcohol, penetrate through pinholes in the protective layer, resulting in discoloration due to the reaction between a leuco dye and a color developing agent contained in the color developing layer by the penetrated solvents.

Bekannt ist außerdem aus der EP-A-211263 (Stand der Technik nach Art 54(3)(4) EPC = JP-OLS Nr. 11681/1987), daß eine Kombination eines Eisensalzes einer gesättigten höheren Fettsäure mit 16 bis 35 Kohlenstoffatomen und eines mehrwertigen Phenolderivates ein wärmeempfindliches Aufzeichnungsblatt ergibt, das für schnelle Aufzeichnung geeignet ist, und das eine uberlegene Lagerbestandigkeit des Aufzeichnungsbildes gegenüber anhaftenden Ölen, Fetten und Lösungsmitteln, wie Alkoholen, aufweist.It is also known from EP-A-211263 (prior art according to Art 54 (3) (4) EPC = JP-OLS No. 11681/1987) that a combination of an iron salt of a saturated higher fatty acid with 16 to 35 carbon atoms and of a polyvalent phenol derivative gives a heat-sensitive recording sheet which is suitable for fast recording and which has a superior storage stability of the recording image against adhering oils, fats and solvents such as alcohols.

Das Eisensalz einer höheren Fettsäure mit 16 bis 35 Kohlenstoffatomen hat beim Vermahlen und Dispergieren mittels einer Mahlvorrichtung wie Kugelmühle, Reibungsmühle, Sandschleifmaschine usw. bis zu einer Teilchengröße von einigen Mikrometern und weniger die Nachteile, daß feine Schäume gebildet werden, die Viskosität erhöht wird und viele Koagulate entstehen.The iron salt of a higher fatty acid with 16 to 35 carbon atoms has the disadvantages that fine foams are formed, the viscosity is increased and many, when grinding and dispersing by means of a grinding device such as a ball mill, attritor, sand grinder, etc., down to a particle size of a few micrometers Coagulates arise.

Die obigen Eisensalze der höheren Fettsäuren als solche sind außerdem schwach farbig, daher ist der Hintergrund eines wärmeempfindlichen Materials bei der Dispergierung der Beschichtungsmasse und dem Auftragen dieser Beschichtungsmasse gefärbt, was zu einem unterlegenen Bildkontrast als Nachteil fuhrt.The above iron salts of the higher fatty acids as such are also weakly colored, so the background of a heat sensitive material is that Dispersion of the coating composition and the application of this coating composition colored, which leads to an inferior image contrast as a disadvantage.

Der Erfindung liegt die Aufgabe zugrunde, ein wärmeempfindliches Aufzeichnungsmaterial zu schaffen, das in der Dispergierung, dem Bildkontrast, der Ölbeständigkeit, der Lösungsmittelbeständigkeit und der optischen Lesbarkeit im nahen ultraroten Bereich überlegen ist.The invention has for its object to provide a heat-sensitive recording material which is superior in dispersion, image contrast, oil resistance, solvent resistance and optical readability in the near ultraviolet range.

Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß das Aufzeichnungsblatt eine auf einen Träger aufgetragene Farbentwicklungsschicht aufweist, die ein Metalldoppelsalz einer höheren Fettsäure mit 16 bis 35 Kohlenstoffatomen als Elektronenakzeptor und einen geeigneten Elektronendonator enthält.This object is achieved according to the invention in that the recording sheet has a color development layer applied to a support which contains a metal double salt of a higher fatty acid having 16 to 35 carbon atoms as an electron acceptor and a suitable electron donor.

Die Art des Elektronendonators ist nicht besonders beschränkt, aber der bevorzugte Elektronendonator wird ausgewählt aus mindestens einer der folgenden Verbindungsgruppen bzw. Verbindungen:
Mehrwertige aromatische Hydroxiverbindungen Diphenylcarbazid, Diphenylcarbazon, Hexamethylentetramin, Spirobenzopyran und 1-Formyl-4-phenylsemicarbazid.The type of electron donor is not particularly limited, but the preferred electron donor is selected from at least one of the following connecting groups or compounds:
Polyvalent aromatic hydroxyl compounds diphenylcarbazide, diphenylcarbazone, hexamethylenetetramine, spirobenzopyran and 1-formyl-4-phenylsemicarbazide.

Das erfindungsgemäße wärmeempfindliche Aufzeichnungsmaterial wird hergestellt, indem man die Beschichtungsmasse, welche die Kombination von einem bisherigen Elektronendonator und einem obigen Elektronenakzeptor enthält, auf einen Basisträger aufträgt.The heat-sensitive recording material according to the invention is produced by applying the coating composition, which contains the combination of a previous electron donor and an above electron acceptor, to a base support.

Die erfindungsgemäßen Metalldoppelsalze höherer Fettsäuren sind Doppelsalze, die pro Molekül mindestens zwei Arten von Metallatomen haben. Sie unterscheiden sich daher deutlich in ihren physikalisch-chemischen Eigenschaften von den bisherigen Metallsalzen der höheren Fettsäuren, die nur eine Metallatomart in ihrem Molekül enthalten.The metal double salts of higher fatty acids according to the invention are double salts which have at least two types of metal atoms per molecule. They therefore differ significantly in their physicochemical properties from the previous metal salts of higher fatty acids, which only contain one type of metal atom in their molecule.

Diese Metalldoppelsalze der höheren Fettsäuren werden hergestellt, indem man mindestens zwei anorganische Metallsalze mit einem Alkalimetallsalz oder Ammoniumsalz der gewählten höheren Fettsäure umsetzt. Die Art und das Mischungsverhältnis der Metallatome der mindestens zwei anorganischen Metallsalze kann auf diese Wiese leicht eingestellt und kontrolliert werden. Beispielsweise kann das Zink-Eisen-Doppelsalz der Behensäure mit Eisen und Zink im Verhältnis 2 : 1 hergestellt werden, indem man Natriumbehenat mit einer wäßrigen Lösung von Ferrichlorid und Zinkchlorid in einem Molverhältnis von 2 : 1 umsetzt.These metal double salts of the higher fatty acids are prepared by reacting at least two inorganic metal salts with an alkali metal salt or ammonium salt of the selected higher fatty acid. The type and the mixing ratio of the metal atoms of the at least two inorganic metal salts can be easily adjusted and controlled in this way. For example, the zinc-iron double salt of behenic acid with iron and zinc in a ratio of 2: 1 can be prepared by mixing sodium behenate with an aqueous solution of ferrichloride and zinc chloride in one Molar ratio of 2: 1 is implemented.

Geeignete Metalle für die Doppelsalzbildung der höheren Fettsäuren sind mehrwertige Metalle, beispielsweise Eisen, Zink, Calcium, Magnesium, Aluminium, Barium, Blei, Mangan, Zinn, Nickel, Kobalt, Kupfer, Silber, Quecksilber usw.; vorzugsweise Eisen, Zink, Calcium, Aluminium, Magnesium und Silber.Suitable metals for the double salt formation of the higher fatty acids are polyvalent metals, for example iron, zinc, calcium, magnesium, aluminum, barium, lead, manganese, tin, nickel, cobalt, copper, silver, mercury, etc .; preferably iron, zinc, calcium, aluminum, magnesium and silver.

Geeignete Fettsäuren für die Doppelsalzbildung sind gesättigte und/oder ungesättigte aliphatische Fettsäuren mit 16 bis 35 Kohlenstoffatomen.Suitable fatty acids for the double salt formation are saturated and / or unsaturated aliphatic fatty acids with 16 to 35 carbon atoms.

Die erfindungsgemäßen Elektronendonatoren, die mit dem Metalldoppelsalz einer höheren Fettsäure verwendet werden, sind vorzugsweise mehrwertige aromatische Hydroxiverbindungen, Dipenylcarbazid, Diphenylcarbazon, Hexamethylentetramin, Spirobenzopyran und 1-Formyl-4-phenylsemicarbazid; am bevorzugtesten sind die mehrwertigen aromatischen Hydroxiverbindungen der allgemeinen Formel (I):

Figure imgb0001

in der R eine Alkylgruppe mit 18 bis 35 Kohlenstoffatomen,
Figure imgb0002
bedeutet
(worin R₁ eine Alkylgruppe mit 18 bis 35 Kohlenstoffatomen bedeutet); n eine ganze Zahl von 2 bis 3 bedeutet; und "-X-" für
-CH₂- , -CO₂- , -CO- , -O- , -CONH- ,
Figure imgb0003
(worin Rʹ eine Alkylgruppe mit 5 bis 30 Kohlenstoffatomen bedeutet), -SO₂ -, -SO₃ - oder - SO₂NH - steht.The electron donors of the invention, which are used with the metal double salt of a higher fatty acid, are preferably polyvalent aromatic hydroxyl compounds, dipenyl carbazide, diphenyl carbazone, hexamethylenetetramine, spirobenzopyran and 1-formyl-4-phenylsemicarbazide; most preferred are the polyvalent aromatic hydroxyl compounds of the general formula (I):
Figure imgb0001
in which R is an alkyl group with 18 to 35 carbon atoms,
Figure imgb0002
means
(wherein R₁ represents an alkyl group having 18 to 35 carbon atoms); n represents an integer from 2 to 3; and "-X-" for
-CH₂-, -CO₂-, -CO-, -O-, -CONH-,
Figure imgb0003
(wherein Rʹ is an alkyl group having 5 to 30 carbon atoms), -SO₂ -, -SO₃ - or - SO₂NH - is.

Die Wahl des erfindungsgemäßen Metalldoppelsalzes einer höheren Fettsäure unterliegt keinen besonderen Einschränkungen, man kann beispielsweise folgende verwenden.

  • 1) Eisen-Zink-Doppelsalz der Stearinsäure
  • 2) Eisen-Zink-Doppelsalz einer Montansäure
  • 3) Eisen-Zink-Doppelsalz einer Wachssäure
  • 4) Eisen-Zink-Doppelsalz der Behensäure
  • 5) Eisen-Calcium-Doppelsalz der Behensäure
  • 6) Einsen-Aluminium-Doppelsalz der Behensäure
  • 7) Eisen-Magnesium-Doppelsalz der Behensäure
  • 8) Silber-Calcium-Doppelsalz der Behensäure
  • 9) Silber-Aluminium-Doppelsalz der Behensäure
  • 10) Silber-Magnesium-Doppelsalz der Behensäure
  • 11) Calcium-Aluminium-Doppelsalz der Behensäure
The choice of the metal double salt of a higher fatty acid according to the invention is not subject to any particular restrictions, for example the following can be used.
  • 1) Iron-zinc double salt of stearic acid
  • 2) Iron-zinc double salt of a montanic acid
  • 3) Iron-zinc double salt of a wax acid
  • 4) Iron-zinc double salt of behenic acid
  • 5) Double iron-calcium salt of behenic acid
  • 6) One-aluminum double salt of behenic acid
  • 7) Iron-magnesium double salt of behenic acid
  • 8) Silver-calcium double salt of behenic acid
  • 9) Silver-aluminum double salt of behenic acid
  • 10) Silver-magnesium double salt of behenic acid
  • 11) Calcium aluminum double salt of behenic acid

Solche Metalldoppelsalze höherer Fettsäuren können als Elektronenakzeptor allein oder im Gemisch verwendet werden.Such metal double salts of higher fatty acids can be used as an electron acceptor alone or in a mixture.

Die Wahl der erfindungsgemäßen mehrwertigen aromatischen Hydroxiverbindungen als Elektronendonator unterliegt keinen besonderen Einschränkungen, man kann beispielsweise eine Verbindung der folgenden Formeln verwenden,
worin R eine Alkylgruppe mit 18 bis 35 C-Atomen und
   Rʹ eine Alkylgruppe mit 5 bis 30 C-Atomen bedeuten,

Figure imgb0004
Figure imgb0005
 The choice of the polyvalent aromatic hydroxyl compounds according to the invention as an electron donor is not subject to any particular restrictions, for example a compound of the following formulas can be used,
wherein R is an alkyl group with 18 to 35 carbon atoms and
Rʹ is an alkyl group with 5 to 30 carbon atoms,
Figure imgb0004
Figure imgb0005

Bei der Herstellung der Beschichtungsmasse durch Dispergieren dieses mehrwertigen Phenolderivats in einem wäßrigen oder lösungsmitteloslichen Bindemittel ist es nötig, eine Reaktion dieses Phenolderivats mit einem Elektronendonator zu vermeiden, und die Lösungsmittel- und Dispersionsstabilität diese Phenols zu erhöhen. Dabei ist es wünschenswert, daß der von der Farbentwicklungsgruppe verschiedene Substituent eine große Zahl von Kohlenstoffatomen, nämlich 18 bis 35, hat, 2 bis 3 OH-Gruppen vorhanden sind, und diese OH-Gruppen nahe beieinander liegen.When preparing the coating composition by dispersing this polyvalent phenol derivative in an aqueous or solvent-free binder, it is necessary to avoid a reaction of this phenol derivative with an electron donor and to increase the solvent and dispersion stability of this phenol. It is desirable that the substituent other than the color developing group has a large number of carbon atoms, namely 18 to 35, 2 to 3 OH groups are present, and these OH groups are close to each other.

Dieses mehrwertige Phenol usw. wird je nach Bedarf allein oder im Gemisch verwendet.This polyhydric phenol, etc. is used alone or in a mixture as needed.

Erfindungsgemäß ist je nach Verwendungszweck und benötigter Funktion des wärmeempfindlichen Aufzeichnungsmaterials eine kombinierte Verwendung einer organischen Säure und/oder des Phenols möglich. Geeignet Farbentwicklungsmittel bei der Verwendung eines farblosen Farbstoffs sind: Bisphenol A, p,pʹ-(1-Methyl-normal-hexyliden)diphenol, p-tertiär-Butylphenol, p-Phenylphenol, p-Hydroxybenzoesaureester, Novolak-Phenolharz, 4-Hydroxy-1-methylsulfonylbenzol, 4-Hydroxy-1-butyloxysulfonylbenzol usw.According to the invention, a combined use of an organic acid and / or the phenol is possible depending on the intended use and the required function of the heat-sensitive recording material. Suitable color developing agents when using a colorless dye are: bisphenol A, p, pʹ- (1-methyl-normal-hexylidene) diphenol, p-tertiary-butylphenol, p-phenylphenol, p-hydroxybenzoic acid ester, novolak phenolic resin, 4-hydroxy 1-methylsulfonylbenzene, 4-hydroxy-1-butyloxysulfonylbenzene, etc.

In bezug auf die Lösungsmittelbeständigkeit gegenüber Alkohlen ist der erfindungsgemäße Elektronendonator besonders überlegen.In terms of solvent resistance to alcohols, the electron donor of the invention is particularly superior.

Man kann verschiedene Additive zugeben, um bestimmte Effekte zu erzielen. Die Additive, die erfindungsgemäß verwendet werden können, sind z.B. folgende:
Mottling-Verhinderungsmittel (beispielsweise Fettsäureamid, Äthylenbisamid, Montanwachs); Sensibilisator (beispielsweise Dibenzyltherephtalat, p-Benzyloxybenzoesäurebenzylester, Di-p-tolylcarbonat, p-Benzylbiphenyl); und Stabilisator (beispielsweise Metallsalz eines Phtalsäuremonoesters, Metallsalz der p-tert,-Butylbenzoesäure, Metallsalz der Nitrobenzoesäure).
Erfindungsgemäß ist die Mitverwendung von farblosen Leukofarbstoffen möglich.
Typische Beispiele für erfindungsgemäße Leukofarbstoffe sind:Various additives can be added to achieve certain effects. The additives which can be used according to the invention are, for example, the following:
Anti-mottling agents (e.g. fatty acid amide, ethylene bisamide, montan wax); Sensitizer (e.g. dibenzyl therephthalate, benzyl p-benzyloxybenzoate, di-p-tolyl carbonate, p-benzyl biphenyl); and stabilizer (for example, metal salt of a phthalic acid monoester, metal salt of p-tert, butylbenzoic acid, metal salt of nitrobenzoic acid).
According to the invention, the use of colorless leuco dyes is possible.
Typical examples of leuco dyes according to the invention are:

LeukofarbstoffLeuco dye derthe TriphenylmethareiheTriphenylmethane series

3,3-Bis(p-dimethylaminophenyl-6-dimethylaminophthalid (Kristallviolettlacton)3,3-bis (p-dimethylaminophenyl-6-dimethylaminophthalide (crystal violet lactone)

LeukofarbstoffLeuco dye derthe FluoranreiheFluorine series

3-Diäthylamino-6-methyl-7-anilinofluoran,
3-(N-Äthyl-p-toluidino)-6-methyl-7-anilinofluoran,
3-(N-Äthyl-N-isoamyl)amino-6-methyl-7-anilinofluoran,
3-Diäthylamino-6-methyl-7-(p,p-dimethylanilino)fluoran,
3-Pyrolidino-6-methyl-7-anilinofluoran,
3-Piperdino-6-methyl-7-anilinofluoran,
3-(N-Cyclohexyl-N-methylamino)-6-methyl-7-anilinofluoran,
3-Diäthylamino-7-(m-trifluoromethylanilino)fluoran,
3-Dibutylamino-7-(o-chloranilino)fluoran,
3-Diäthylamino-6-methyl-chlorfluoran,
3-Diäthylamino-6-methylfluoran,
3-Cyclohexylamino-6-chlorfluoran,
3-Diäthylamino-7-(o-chloranilino)fluoran,
3-Diäthylamino-benzo-(a)-fluoran.3-diethylamino-6-methyl-7-anilinofluoran,
3- (N-ethyl-p-toluidino) -6-methyl-7-anilinofluoran,
3- (N-ethyl-N-isoamyl) amino-6-methyl-7-anilinofluoran,
3-diethylamino-6-methyl-7- (p, p-dimethylanilino) fluoran,
3-pyrolidino-6-methyl-7-anilinofluoran,
3-piperdino-6-methyl-7-anilinofluoran,
3- (N-cyclohexyl-N-methylamino) -6-methyl-7-anilinofluoran,
3-diethylamino-7- (m-trifluoromethylanilino) fluoran,
3-dibutylamino-7- (o-chloroanilino) fluoran,
3-diethylamino-6-methylchlorofluoran,
3-diethylamino-6-methylfluorane,
3-cyclohexylamino-6-chlorofluorane,
3-diethylamino-7- (o-chloroanilino) fluoran,
3-diethylamino-benzo- (a) -fluorane.

LeukofarbstoffLeuco dye derthe AzaphthalidreiheAzaphthalide series

3-(4-Diäthylamino-2-äthoxyphenyl)-3-(1-äthyl-2-methylindol-3-yl)-4-azaphthalid,
3-(4-Diäthylamino-2-äthoxyphenyl)-3-(1-äthyl-2-methylindol-3-yl)-7-azaphthalid,
3-(4-Diäthylamino-2-äthoxyphenyl)-3-1-octyl-2-methylindol-3-yl)-4-azaphthalid,
3-(4-N-cyclohexyl-N-methylanilino-2-methoxyphenyl)-3-(1-äthyl-2-methylindol-3-yl)-4-azaphthalid.3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide,
3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -7-azaphthalide,
3- (4-diethylamino-2-ethoxyphenyl) -3-1-octyl-2-methylindol-3-yl) -4-azaphthalide,
3- (4-N-cyclohexyl-N-methylanilino-2-methoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide.

LeukofarbstoffLeuco dye derthe FluorenreiheFluorene series

3,6,6ʹ-Tris(dimethylamino)-spiro (fluoren-9,3ʹ-phthalid)
3,6,6ʹ-Tris(diäthylamino)-spiro (fluoren-9,3ʹ-phthalid)3,6,6ʹ-tris (dimethylamino) -spiro (fluorene-9,3ʹ-phthalide)
3,6,6ʹ-tris (diethylamino) -spiro (fluorene-9,3ʹ-phthalide)

Erfindungsgemäße Bindemittel sind z. B. völlig verseifter Polyvinylalkohol, Polymerisationsgrad: 200-1900, teilweise verseifter Polyvinylalkohol, karboxylierter Polyvinylalkohol amidmodifizierter Polyvinylakohol, sulfonsäuremodifizierter Polyvinylalkohol, butyralmodifizierter Polyvinylalkohol, andere modifizierte Polyvinylalkohole, Hydroxyathylzellulose, Methylzellulose, Carboxymethylzellulose, Styrol-Maleinsäureanhydrid-Copolymere, Styrol-Butadien-Copolymere, Zellulosederivate wie Äthylzellulose und Acetylzellulose, Polyvinylchlorid, Polyvinylazetat, Polyacrylamid, Polyacrylsäureester, Polyvinylbutyral, Polystyrol, Copolymere von obigen Verbindungen, Polyamidharz, Siliconharz, Petroleumkunstharz, Terpenharz, Ketonharz und Cumaronharz. Diese hochmolekularen Bindemittel können verwendet werden, nachdem sie in einem Lösungsmittel wie Wasser, Alkohol, Keton, Ester, Kohlenwasserstoff usw. gelöst oder in Wasser oder Lösungsmittel emulgiert oder dispergiert wurden.Binders according to the invention are e.g. B. fully saponified polyvinyl alcohol, degree of polymerization: 200-1900, partially saponified polyvinyl alcohol, carboxylated polyvinyl alcohol, amide-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, butyral-modified polyvinyl alcohol, other modified polyvinyl alcohols, hydroxyethyl cellulose, Methyl cellulose, carboxymethyl cellulose, styrene-maleic anhydride copolymers, styrene-butadiene copolymers, cellulose derivatives such as ethyl cellulose and acetyl cellulose, polyvinyl chloride, polyvinyl acetate, polyacrylamide, polyacrylic acid ester, polyvinyl butyral, polystyrene, copolymers of the above compounds, polyamide resin, cylon resin, silicone resin, polyamide resin, silicone resin . These high molecular weight binders can be used after being dissolved in a solvent such as water, alcohol, ketone, ester, hydrocarbon, etc., or emulsified or dispersed in water or solvent.

Die Art und Menge des Metalldoppelsalzes der höheren Fettsäure, des mehrwertigen Phenolderivats, des Bindemittels, der anderen Additive, die je nach dem gewünschten Effekt und der Eignung für Aufzeichnungszwecke bestimmt werden, sind nicht besonders beschränkt. Im allgemeinen ist es vorteilhaft, 1 bis 6 Gew.-Teile des Elektronendonators und 2 bis 15 Gew.-Teile Füllstoff, bezogen auf 1 bis 9 Teile des Metalldoppelsalzes der höheren Fettsäure, zu verwenden und 0,5 bis 4 Gew.-Teile Bindemittel, bezogen auf den Gesamtfeststoffgehalt, zu verwenden.The type and amount of the metal double salt of the higher fatty acid, the polyhydric phenol derivative, the binder, the other additives, which are determined depending on the desired effect and suitability for recording purposes, are not particularly limited. In general, it is advantageous to use 1 to 6 parts by weight of the electron donor and 2 to 15 parts by weight of filler, based on 1 to 9 parts of the metal double salt of the higher fatty acid, and 0.5 to 4 parts by weight of binder , based on the total solids content.

Das erfindungsgemäße wärmeempfindliche Material wird hergestellt, indem man die Beschichtungsmasse auf ein Basismaterial wie Papier, synthetisches Papier, Film usw. aufträgt.The heat-sensitive material according to the invention is produced by applying the coating composition to a base material such as paper, synthetic paper, film, etc.

Das oben erwähnte Metalldoppelsalz einer höheren Fettsäure, der obige Elektronendonator, gegebenenfalls das organische Farbentwicklungsmittel und der basische, farblose chromogene Farbstoff werden mittels einer Mahlvorrichtung, wie Kugelmühle, Reibungsmühle, Sandschleifmaschine usw., oder mittels einer geeigneten Emulgiermaschine bis zu einer Teilchengröße von mehreren Mikron oder kleiner zermahlen. Hierzu gibt man verschiedene Additive. Die Additive, die erfindungsgemäß verwendet werden können, sind z.B. folgende:
Anorganische oder organische Füllstoffe, wie Siliziumdioxyd, Calciumcarbonat, Kaolin, gebrannter Kaolin, Diatomeenerde, Talk, Titaniumdioxid, Aluminiumhydroxid usw.; Trennmittel wie Metallsalze von Fettsäuren; Gleitmittel wie Wachse; UV-Absorptionsmittel der Benzophenon- und Triazolreihe; wasserfest machende Mittel wie Glyoxal usw., Dispergiermittel; Antischaummittel und so weiter.The above-mentioned metal double salt of a higher fatty acid, the above electron donor, optionally the organic color developing agent and the basic, colorless chromogenic dye are by means of a grinding device such as a ball mill, attritor, sanding machine, etc., or by means of a suitable emulsifying machine to a particle size of several microns or grind smaller. Various additives are added to this. The additives which can be used according to the invention are, for example, the following:
Inorganic or organic fillers such as silicon dioxide, calcium carbonate, kaolin, baked kaolin, diatomaceous earth, talc, titanium dioxide, aluminum hydroxide, etc .; Release agents such as metal salts of fatty acids; Lubricants such as waxes; UV absorbers of the benzophenone and triazole series; waterproofing agents such as glyoxal, etc., dispersants; Antifoam and so on.

Über die Ursache für die überlegene Dispergierbarkeit der erfindungsgemäßen Metalldoppelsalze höherer Fettsäuren kann man Vermutungen anstellen. Im allgemeinen hat das Metallsalz einer höheren Fettsäure sowohl hydrophile Gruppen als auch hydrophobe Gruppen, es hat daher die Eigenschaften einer oberflächenaktiven Substanz. Deshalb hat es beim Vermahlen und Dispergieren mittels einer Mahlvorrichtung wie Kugelmühle, Reibungsmühle, Sandschleifmaschine usw. bis zu einer Teilchengröße von einigen Mikron und weniger die Nachteile, daß Schäume gebildet werden, die Viskosität erhöht wird und viele Koagulate entstehen. Überraschenderweise ist dies bei Verwendung der erfindungsgemäßen Doppelsalze nicht der Fall. Vielleicht verursachen die verschiedenen Metalle feine Unterschiede in den oberflächenaktiven Eigenschaften, so daß die Dispergierbarkeit erhöht wird.One can speculate as to the reason for the superior dispersibility of the metal double salts of higher fatty acids according to the invention. In general, the metal salt of a higher fatty acid has both hydrophilic groups and hydrophobic groups, and therefore has the properties of a surfactant. Therefore, when grinding and dispersing by means of a grinding device such as a ball mill, attritor, sand grinder, etc. down to a particle size of a few microns and less, it has the disadvantages that foams are formed, the viscosity is increased and many coagulates are formed. Surprisingly, this is not the case when using the double salts according to the invention. Perhaps the different metals cause subtle differences in the surface-active properties, so that the dispersibility is increased.

Die überlegene optische Lesbarkeit des erfindungsgemäßen wärmeempfindlichen Aufzeichnungsblattes im nahen ultraroten Bereich hat vielleicht folgende Ursache. Bei der Farbbildung durch die Hitzeschmelzreaktion ergibt der Farbentwicklungsbereich ein im sichtbaren Bereich und im nahen ultraroten Bereich (Wellenlängebereich von 700 bis 1000 nm) lesbares Aufzeichnungsbild. Man vermutet, daß die Ursache für die überlegene Beständigkeit des Aufzeichnungsbildes gegenüber Öl und Lösungsmittel eine irreversible, beim Schmelzen in der Hitze erfolgende Farbbildungsreaktion ist, die zwischen einem Metalldoppelsalz der höheren Fettsäure als Elektronenakzeptor und einem mehrwertigen Phenolderivat usw. als Elektronendonator stattfindet. D.h. bei der Hitze-Schmelz-Farbbildungsreaktion wird ein sehr stabiler Komplex gebildet, der durch anhaftendes Haaröl, Ölmaterialien und Lösungsmittel, wie Alkohol, nicht gelöst wird.The superior optical readability of the heat-sensitive recording sheet of the present invention in the near-red range may have the following cause. When the color is formed by the heat-melt reaction, the color development area results in a recordable image in the visible range and in the near ultra-red range (wavelength range from 700 to 1000 nm). It is believed that the cause of the superior resistance of the recording image to oil and solvent is an irreversible color-forming reaction which occurs when it is melted and which occurs between a metal double salt of the higher fatty acid as an electron acceptor and a polyvalent phenol derivative, etc. as an electron donor. I.e. the heat-melt color formation reaction forms a very stable complex which is not dissolved by adhering hair oil, oil materials and solvents such as alcohol.

Vielleicht läßt sich die große Beständigkeit des Hintergrundes gegenüber Öl und Lösungsmittel darauf zurückführen, daß das erfindungsgemäße Metalldoppelsalz höherer Fettsäuren16-35 Kohlenstoffatome pro. Molekül besitzt, und daß daher die Löslichkeit in dem Haaröl, den Ölmaterialien und dem organischen Lösungsmittel wie Alkohol usw. sehr klein ist, so daß bei der Berührung mit der Verschmutzungssubstanz keine chemische Reaktion zwischen dem Metalldoppelsalz höherer Fettsäuren und dem Elektronendonator, wie einem mehrwertigen Phenol, usw. abläuft. Auch der bessere Bildkontrast überrascht.Perhaps the great resistance of the background to oil and solvents can be attributed to the fact that the metal double salt of higher fatty acids according to the invention has 16-35 carbon atoms per. Molecule has, and therefore that Solubility in the hair oil, the oil materials and the organic solvent such as alcohol, etc. is very small, so that when it comes into contact with the contaminant, there is no chemical reaction between the metal double salt of higher fatty acids and the electron donor, such as a polyhydric phenol, etc. The better image contrast is also surprising.

Im allgemeinen haben die Metallsalze höherer Fettsäuren je nach den Eigenschaften der Metalle verschiedene Farben, von farblos bis deutlich gefärbt. Beispielsweise ist das Eisensalz höherer Fettsäuren schwach gelb, dagegen das Zinksalz der höheren Fettsäuren farblos. Das Eisen-Zinkdoppelsalz einer Fettsäure, bei dem Eisen und Zink in einem Molekül vorliegen, ist nur ganz schwach gefärbt, was zu einer nur sehr geringen Färbung des wärmeempfindlichen Aufzeichnungsmaterials nach dem Auftragen der durch die Dispergierung des Doppelsalzes erhaltenen Beschichtungsmasse führt. In dieser Weise kann man durch geeignete Kombination der Metalle ein wärmeempfindliches Aufzeichnungsmaterial mit sehr gering gefärbtem Hintergrund herstellen.In general, the metal salts of higher fatty acids have different colors, from colorless to clearly colored, depending on the properties of the metals. For example, the iron salt of higher fatty acids is pale yellow, whereas the zinc salt of higher fatty acids is colorless. The iron-zinc double salt of a fatty acid, in which iron and zinc are present in one molecule, is only very weakly colored, which leads to only a very slight coloration of the heat-sensitive recording material after application of the coating material obtained by dispersing the double salt. In this way, a suitable combination of the metals can be used to produce a heat-sensitive recording material with a very lightly colored background.

Die Erfindung wird anhand der nachfolgenden Beispiele näher erläutert.
Als Abkürzung für Gewichsteile wird "Teile" verwendet.

Figure imgb0006
The invention is illustrated by the following examples.
As an abbreviation for parts by weight, "parts" is used.
Figure imgb0006

Die Lösungen der obigen Zusammensetzungen wurden in einer Reibungsmühle einzeln bis zur Teilchengröße von 3 Mikron vermahlen.The solutions of the above compositions were individually milled in a attritor to a particle size of 3 microns.

Die Lösungen wurden dann im folgenden Verhältnis miteinander und mit Zusätzen zu einer wärmeempfindlichen Beschichtungsmasse vermischt:

Figure imgb0007
The solutions were then mixed in the following ratio with one another and with additives to form a heat-sensitive coating composition:
Figure imgb0007

Diese Beschichtungsmasse wurde in einer Beschichtungsmenge von 6,0 g/m² auf ein Basispapier mit einem Gewicht von 50 g/m² aufgetragen, getrocknet und superkalandriert, um eine Glätte von 200-600 Sekunden einzustellen. Man erhielt ein wärmeempfindliches Aufzeichnungsblatt.

Figure imgb0008
Figure imgb0009
 This coating composition was applied in a coating amount of 6.0 g / m² on a base paper with a weight of 50 g / m², dried and supercalendered to achieve a smoothness of 200-600 seconds. A heat sensitive recording sheet was obtained.
Figure imgb0008
Figure imgb0009

Die Lösungen der obigen Zusammensetzungen wurden in einer Reibungsmühle einzeln bis zur Teilchengröße von 3 Mikron vermahlen.
Die Lösungen wurden dann im gleichen Verhältnis wie in den Beispielen miteinander vermischt, man erhält dabei eine wärmeempfindliche Beschichtungsmasse.
Diese Beschichtungsmasse wurde in einer Beschichtungsmenge von 6,0 g/m² auf ein Basispapier mit einem Gewicht von 50 g/m² aufgetragen, getrocknet und superkalandriert, um eine Glätte von 200-600 Sekunden einzustellen. Man erhielt ein wärmeempfindliches Aufzeichnungsblatt. Die in den Beispielen und Vergleichsbeispielen erhaltenen Aufzeichnungsblätter wurden hinsichtlich der in den Tabellen 1 und 2 angegebenen Qualitäten geprüft, dort sind auch die Ergebnisse zusammengefaßt.

Figure imgb0010
Figure imgb0011
 The solutions of the above compositions were individually milled in a attritor to a particle size of 3 microns.
The solutions were then mixed together in the same ratio as in the examples, a heat-sensitive coating composition being obtained.
This coating composition was applied in a coating amount of 6.0 g / m² on a base paper with a weight of 50 g / m², dried and supercalendered to achieve a smoothness of 200-600 seconds. A heat sensitive recording sheet was obtained. The recording sheets obtained in the examples and comparative examples were tested for the qualities given in Tables 1 and 2, where the results are also summarized.
Figure imgb0010
Figure imgb0011

AnmerkungenRemarks

  • (1) Bilddichte: Ein wärmeempfindliches Aufzeichnungsblatt wird bei einer angelegten Spannung von 18.03 V und einer Pulsbreite von 3,2 Millisekunden unter Verwendung einer Faksimiliermaschine (von TOSHIBA CORPORATION) mit einer Aufzeichnung versehen. Die Bilddichte wird mit einem Macbeth-Dichtemesser (RD-514, Verwendung des Amber-Filters; die unten beschriebenen Messungen erfolgen unter gleichen Bedingungen) bestimmt.(1) Image density: A heat-sensitive recording sheet is recorded with an applied voltage of 18.03 V and a pulse width of 3.2 milliseconds using a facsimile machine (from TOSHIBA CORPORATION). The image density is determined using a Macbeth density meter (RD-514, using the amber filter; the measurements described below are carried out under the same conditions).
  • (2) Hintergrund: Der leere, freie Teil des Blattes wird mit einem Macbeth-Dichtemesser ausgemessen.(2) Background: The empty, free part of the sheet is measured with a Macbeth density meter.
  • (3) Färbungsgrad des Hintergrundes: Der Färbungsgrad des Hintergrundes wird visuell bewertet und in drei Gruppen eingeteilt: fast nicht, etwas, und viel.(3) Degree of coloration of the background: The degree of coloration of the background is assessed visually and divided into three groups: almost not, something, and a lot.
  • (4) Beständigkeit gegenüber Öl: Ein wärmeempfindliches Aufzeichnungsblatt wird bei einer angelegten Spannung von 18,03 V und einer Pulsbreite von 3,2 Millisekunden unter Verwendung einer Faksimiliermaschine KB-4800 mit einer Aufzeichung versehen, deren Bilddichte bestimmt wird (nachfolgend als Bilddichte vor der Ölbehandlung bezeichnet). Rizinusöl wird auf die Aufzeichnung getröpfelt und nach 3 Tagen mit einem Filtrierpapier weggewischt. Danach wird die Bilddichte (nach der Ölbehandlung) mit einem Macbeth-Dichtemesser gemessen. Der Restprozentsatz wird nach folgender Formel berechnet.
    Figure imgb0012
         (4) Resistance to oil: A heat-sensitive recording sheet is recorded with an applied voltage of 18.03 V and a pulse width of 3.2 milliseconds using a KB-4800 facsimile machine, the image density of which is determined (hereinafter referred to as the image density before Oil treatment). Castor oil is dripped onto the recording and wiped off with filter paper after 3 days. Then the image density (after oil treatment) with a Macbeth density meter measured. The remaining percentage is calculated using the following formula.
    Figure imgb0012
  • (5) Reflexionsgrad für ultrarotes Licht:
    Der Reflexionsgrad der in obiger Anmerkung (1) erwähnten Aufzeichnung wird mit einem Spektrophotometer bei einer Wellenlänge von 800 nm gemessen.    (5) Reflectance for ultra red light:
    The reflectance of the recording mentioned in note (1) above is measured with a spectrophotometer at a wavelength of 800 nm.
  • (6) Dispergierbarkeit: Die Dispersion A des Metallsalzes einer höheren Fettsäure wird geprüft. Die Viskosität wird mit einem Viskosimeter (B-Typ, von Tokyo Keiki Co.) gemessen. Der Koagulationsgrad wird mit dem Mikroskop beobachtet, und die Schaumbildung wird visuell wie folgt bewertet: kein, etwas, und viel.(6) Dispersibility: The dispersion A of the metal salt of a higher fatty acid is checked. The viscosity is measured with a viscometer (B type, from Tokyo Keiki Co.). The degree of coagulation is observed with the microscope and the foaming is assessed visually as follows: none, something, and a lot.
  • (7) Lösungsmittelbeständigkeit (des Hintergrundes): Der leere, freie Teil des Blattes, auf den eine 95%ige Alkohollösung getropft worden ist, wird mit einem Macbeth-Dichtemesser kontrolliert. Die Bilddichtedifferenz wird nach folgender Formel berechnet.
    Bilddichtedifferenz
    =[Hintergrund-Bilddichte nach der Lösungsmittelbehandlung]-[Hintergrund-Bilddichte vor der Lösungsmittelbehandlung]    (7) Solvent resistance (of the background): The empty, free part of the sheet on which a 95% alcohol solution has been dropped is checked with a Macbeth density meter. The difference in image density is calculated using the following formula.
    Image density difference
    = [Background Image Density After Solvent Treatment] - [Background Image Density Before Solvent Treatment]
  • (8) Lösungsmittelbeständigkeit (des Blattes mit Aufzeichnung: Das Blatt mit Aufzeichung gemäß obiger Anmerkung (1) wird 30 Minuten mit einer 95%-igen Alkohollösung imprägniert, anschließend wird die Bilddichte mit einem Macbeth-Dichtemesser bestimmt. Der Restprozentsatz wird nach folgender Formel berechnet:
    Figure imgb0013
         (8) Solvent resistance (of the sheet with recording: The sheet with the recording according to note (1) above is impregnated for 30 minutes with a 95% alcohol solution, then the image density is determined using a Macbeth density meter. The remaining percentage is calculated using the following formula :
    Figure imgb0013

Das erfindungsgemäße Aufzeichnungsmaterial weist folgende Vorteile auf:

  • (1) Gute Dispergierbarkeit
  • (2) Überlegener Bildkontrast
  • (3) Verbesserte optische Lesbarkeit, auch im nahen ultraroten Bereich
  • (4) Gute Stabilität des Hintergrundes und des Aufzeichnungsbilds gegenüber anhaftenden Ölmaterialien wie Haaröl, Hautöl usw.
  • (5) Keine Farbentwicklung, und kein Ausfließen der Farbentwicklungsschicht bei Verschmutzung mit Lösungsmittel wie Alkohol, Aceton usw.
The recording material according to the invention has the following advantages:
  • (1) Good dispersibility
  • (2) Superior image contrast
  • (3) Improved optical readability, even in the near ultra-red range
  • (4) Good stability of the background and the recording image against adhering oil materials such as hair oil, skin oil, etc.
  • (5) No color development, and no leakage of the color development layer when contaminated with solvents such as alcohol, acetone, etc.

Claims (10)

  1. Heat sensitive recording material with a colour developing layer, which contains an electron acceptor and an electron donor as well as customary additives, characterised in that the electron acceptor is a metal double salt of a higher fatty acid with 16 to 35 carbon atoms.
  2. Heat sensitive recording material in accordance with Claim 1, characterised in that the metal double salt of a higher fatty acid contains at least two metals from the group iron, zinc, calcium, magnesium, aluminium, barium, lead, manganese, tin, nickel, cobalt, copper, silver and mercury.
  3. Heat sensitive recording material according to one of the preceding Claims, characterised in that the higher fatty acid is palmitic, stearic, arachic, behenic, lignoceric, cerotic, a montanic or a wax acid.
  4. Heat sensitive recording material according to one of the preceding Claims, characterised in that in the double salt the metal combination iron/zinc; iron/aluminium; iron/calcium; iron/magnesium; silver/calcium; silver/aluminium; silver/magnesium or calcium/aluminium is present.
  5. Heat sensitive recording material according to one of the preceding Claims, characterised in that the electron donor is at least one substance chosen from polyvalent aromatic hydroxy compounds, diphenyl carbazide, diphenyl carbazone, hexamethylene tetramine, spirobenzopyran and 1-formyl-4-phenyl-semi-carbazide.
  6. Heat sensitive recording material according to one of the preceding Claims, characterised in that the electron donor is at least one polyvalent aromatic hydroxy compound of the general formula (I):
    Figure imgb0017
     in which R represents an alkyl group with 18 to 35 carbon atoms,
    Figure imgb0018
     (wherein R₁ represents an alkyl group of 18 to 35 carbon atoms); n represents a whole number from 2 to 3; and "-X-" stands for
    -CH₂-, -CO₂-, -CO-, -O-, -CONH-,
    Figure imgb0019
     (wherein R' represents an alkyl group of 5 to 30 carbon atoms), -SO₂-, -SO₃- or -SO₂NH-.
  7. Heat sensitive recording material according to one of the preceding Claims, characterised in that the colour developing layer contains 1 to 6 parts by weight electron donor and 2 - 15 parts by weight filler taken on 1 - 9 parts by weight metal double salt of a higher fatty acid and 0.4 to 4 parts by weight binding agent taken on the total material content.
  8. Heat sensitive recording material according to one of the preceding Claims, characterised in that the colour developing layer lies on a base material.
  9. Heat sensitive recording material according to one of the preceding Claims, characterised in that the base material is a paper, synthetic paper or a film.
  10. Heat sensitive recording material according to one of the preceding Claims, characterised in that the colour developing layer additionally contains a colourless leuco dyestuff.
EP87107971A 1986-06-03 1987-06-02 Heat-sensitive registration material Expired - Lifetime EP0248405B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP128691/86 1986-06-03
JP61128691A JPS62284782A (en) 1986-06-03 1986-06-03 Thermal recording material

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EP0248405A2 EP0248405A2 (en) 1987-12-09
EP0248405A3 EP0248405A3 (en) 1989-04-26
EP0248405B1 true EP0248405B1 (en) 1991-12-11

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JP (1) JPS62284782A (en)
CA (1) CA1263020A (en)
DE (1) DE3775117D1 (en)

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JPH0669755B2 (en) * 1987-02-25 1994-09-07 日本製紙株式会社 Thermal recording
GB8911419D0 (en) * 1989-05-18 1989-07-05 Smith & Mclaurin Limited Heat-sensitive record material
JP2681907B2 (en) * 1992-11-20 1997-11-26 日本製紙株式会社 Thermal recording medium
US5498772A (en) * 1993-10-14 1996-03-12 Mitsubishi Paper Mills Limited Reversible heat-sensitive recording material
US6093528A (en) * 1997-09-17 2000-07-25 Agfa-Gevaert Reducing agents for use in thermographic recording materials
EP0903625B1 (en) * 1997-09-17 2003-05-14 Agfa-Gevaert Thermographic recording materials
US6287755B1 (en) * 1998-04-20 2001-09-11 Konica Corporation Thermally developable photosensitive material
US6211115B1 (en) 1998-08-07 2001-04-03 Agfa-Gevaert Reducing agents for use in thermographic recording materials
EP0978760B1 (en) * 1998-08-07 2003-07-02 Agfa-Gevaert Thermographic recording materials
FI110677B (en) * 2001-10-12 2003-03-14 Jujo Thermal Oy Heat-sensitive recording material for use in, e.g. stickers, has coating layer comprising chelate-type color forming system and leuco dye with urea-based developer
GB0400813D0 (en) * 2004-01-14 2004-02-18 Sherwood Technology Ltd Laser imaging
EP2325018A1 (en) 2009-11-24 2011-05-25 Mondi Uncoated Fine & Kraft Paper GmbH Thermally sensitive recording material

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US3795532A (en) * 1971-03-10 1974-04-05 Minnesota Mining & Mfg Wide latitude copy sheet
US4461496A (en) * 1982-08-17 1984-07-24 Minnesota Mining And Manufacturing Company Soap having improved carbonless imaging properties
JPS5989193A (en) * 1982-11-15 1984-05-23 Ricoh Co Ltd Thermal recording material
US4531141A (en) * 1983-01-17 1985-07-23 Minnesota Mining And Manufacturing Company Heat-sensitive composition and imaging sheet incorporating same
JPS6211681A (en) * 1985-07-10 1987-01-20 Jujo Paper Co Ltd Thermal recording body
JPS62105688A (en) * 1985-11-01 1987-05-16 Jujo Paper Co Ltd Thermosensitive recording medium
JPH01163890A (en) * 1987-12-21 1989-06-28 Toshiba Corp Room occupation control system

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JPH0478115B2 (en) 1992-12-10
JPS62284782A (en) 1987-12-10
US4849396A (en) 1989-07-18
DE3775117D1 (en) 1992-01-23
EP0248405A3 (en) 1989-04-26
EP0248405A2 (en) 1987-12-09

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