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
  • B41M5/40—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used characterised by the base backcoat, intermediate, or covering layers, e.g. for thermal transfer dye-donor or dye-receiver sheets; Heat, radiation filtering or absorbing means or layers; combined with other image registration layers or compositions; Special originals for reproduction by thermography
  • B41M5/42—Intermediate, backcoat, or covering layers
• • 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
  • B41M5/337—Additives; Binders
  • B41M5/3375—Non-macromolecular compounds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M2205/00—Printing methods or features related to printing methods; Location or type of the layers
  • B41M2205/04—Direct thermal recording [DTR]
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M2205/00—Printing methods or features related to printing methods; Location or type of the layers
  • B41M2205/38—Intermediate layers; Layers between substrate and imaging layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M2205/00—Printing methods or features related to printing methods; Location or type of the layers
  • B41M2205/40—Cover layers; Layers separated from substrate by imaging layer; Protective layers; Layers applied before imaging
• • 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
  • B41M5/323—Organic colour formers, e.g. leuco dyes
  • B41M5/327—Organic colour formers, e.g. leuco dyes with a lactone or lactam ring
  • B41M5/3275—Fluoran compounds
• • 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
• • 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
  • B41M5/40—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used characterised by the base backcoat, intermediate, or covering layers, e.g. for thermal transfer dye-donor or dye-receiver sheets; Heat, radiation filtering or absorbing means or layers; combined with other image registration layers or compositions; Special originals for reproduction by thermography
  • B41M5/42—Intermediate, backcoat, or covering layers
  • B41M5/423—Intermediate, backcoat, or covering layers characterised by non-macromolecular compounds, e.g. waxes
• • 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
  • B41M5/40—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used characterised by the base backcoat, intermediate, or covering layers, e.g. for thermal transfer dye-donor or dye-receiver sheets; Heat, radiation filtering or absorbing means or layers; combined with other image registration layers or compositions; Special originals for reproduction by thermography
  • B41M5/42—Intermediate, backcoat, or covering layers
  • B41M5/426—Intermediate, backcoat, or covering layers characterised by inorganic compounds, e.g. metals, metal salts, metal complexes

Definitions

• thermosensitive recording material having an authenticating feature comprising a substrate, optionally a pigmented intermediate layer applied to the substrate, and a thermosensitive recording layer containing color formers and color acceptors.
• Recording materials of this kind determine daily life in society and in professional life.
• recording materials the authorized use of which is generally to be demonstrated by a specific marking of the material approved for this purpose, various solutions of authenticity-proofing security features have already been proposed in the past.
• the present invention was then based on the object of providing an authentication feature for a recording material which should not be visible at all times and immediately, but only from a desired point in time at which the authenticity of the recording material carrying the feature should be visible.
• the specified object is achieved by a heat-sensitive recording material having an authentication feature comprising a substrate and a thermosensitive recording layer containing a color former and color acceptors, color formers and color acceptors reacting with each other in a color-forming manner under the action of heat.
• the proposed recording material has as an authentication feature an additional layer of non-colored, water-soluble and / or alcohol-soluble solid particles, the solid particles being strongly alkaline-reactive in an aqueous solution.
• color in connection with the solid particles does not mean that they appear whitish or whitish in the dry state, while a water or alcohol solution with these solid particles is transparent.
• the solid particles are highly alkaline reactive, which means that such an aqueous solution has a pH above 9.0, preferably above 10.0, and more preferably above 11.0.
• stamping and, in general, all analog printing methods, in particular offset printing have proven to be useful without being limited in any way.
• the application of the additional layer by means of inkjet printing is suitable.
• heat-sensitive recording materials having an additional layer stamped on the heat-sensitive recording layer are particularly preferred.
• a good example of the solid particles of the additional layer is guanidine carbonate.
• a 15% aqueous Guanidincarbonat solution with a pH of 11.5, in a preferred embodiment with an addition of, based on the aqueous guanidine carbonate solution, 5% ethanol provided, can be excellent as an authentication feature on the heat-sensitive recording layer Apply, with a layer formed in this way also quickly absorbs and dries.
• Guanidine carbonate is outstandingly capable of blocking the color-forming reaction of color formers and color acceptors when heat is given by the formation of a strongly alkaline environment, wherein this blocking is essentially sharply defined in the invention and takes place in the form of the intended pattern.
• a disadvantage of Guanidincarbonat is its low stability, which is characterized by a shows gray to yellowish discoloration. If, however, the recording material according to the invention is used only for a comparatively short period of a few hours up to a few days, guanidine carbonate is very easy to use owing to low procurement prices.
• Another example of the solid particles of the additional layer is arginine satisfying the following formula (1):
• Arginine does not have the disadvantages of low stability and at the same time is able to ensure very sharp-edged blockages of the color-forming reaction of color former and dye acceptors when heat is applied.
• a 3 to 5% aqueous arginine solution is preferably used for application to the heat-sensitive recording layer.
• a wetting agent, in particular olefin, and, based on the arginine solution, to 1 to 3.5%, for example, 12% polyvinylalcohol solution and 4 to 8% ethanol are added.
• Another example of the solid particles of the additional layer is lysine.
• the heat-sensitive recording material according to the invention may comprise as color former at least one substance selected from the group of phthalide, xanthene, fluoran, triarylmethane, diphenylmethane, fluorene, oxazine, thiazine or spiropyran compounds known from the prior art where xanthene compounds are considered preferred.
• Typical compounds of this type are, for example:
• the recording layer can also contain, for example, one or more of the following near infrared absorbing compounds:
• Very particularly preferred color formers in the heat-sensitive recording layer in the context of the present invention are those substances selected from the list comprising: 3-diethylamino-6-methyl-7-anilinofluoran, 3-dibutylamino-6-methyl-7-anilinofluoran, 3 (N-methyl-N-propyl) amino-6-methyl-7-anilinofluoran, 3- (N-ethyl-N-isoamyl) amino-6-methyl-7-anilinofluoran, 3- (N-methyl-N- cyclohexyl) amino-6-methyl-7-anilinofluoran, 3- (N-ethyl-N-tolyl) amino-6-methyl-7-anilinofluoran and 3- (N-ethyl-N-tetrahydrofuryl) -amino-6-methyl -7-anilinofluoran.
• the recording layer of the heat-sensitive recording material of the present invention can be basically any of those mentioned above, and in particular to the preferred color formers listed in the individual suitable Farbakzeptoren, in particular organic Farbakzeptoren include.
• the heat-sensitive recording layer has, as a color acceptor, N- (p-toluenesulphonyl) -N'-3- (p-toluenesulphonyl-oxy-phenyl) -urea according to the formula (2) on.
• the recording layer of the heat-sensitive recording material of the present invention may also preferably contain sensitisers having a melting point of preferably from 60 ° C to 180 ° C, more preferably having a melting point of from 80 ° C to 140 ° C, to increase the thermal responsiveness.
• Such sensitizers are, for example: benzyl p-benzyloxybenzoate, stearamide, N-methylol stearamide, p-benzylbiphenyl, 1,2-di (phenoxy) ethane, 1,2-di (m-methylphenoxy) ethane, m-terphenyl, Dibenzyl oxalate, benzyl naphthyl ether, diphenyl sulfone, etc., with benzyl naphthyl ether, diphenyl sulfone, 1,2-di (m-methylphenoxy) ethane and 1,2-di (phenoxy) ethane being preferred.
• Suitable binders for incorporation into the heat-sensitive recording layer are, for example, water-soluble binders such as starch, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, polyvinyl alcohols, modified polyvinyl alcohols, sodium polyacrylates, acrylamide-acrylate copolymers, acrylamide-acrylate-methacrylate terpolymers, alkali metal salts of styrene.
• water-soluble binders such as starch, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, polyvinyl alcohols, modified polyvinyl alcohols, sodium polyacrylates, acrylamide-acrylate copolymers, acrylamide-acrylate-methacrylate terpolymers, alkali metal salts of styrene.
• water-insoluble latex binders such as styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, methyl acrylate-butadiene copolymers, etc. are suitable as binders for incorporation into the heat-sensitive recording layer.
• thermosensitive recording layer For the purposes of the present invention are polyvinyl alcohol alone and / or in conjunction with acrylate copolymers and / or in conjunction with methyl cellulose as particularly preferred binders which together, based on the total weight (atro) of the recording layer, in a range of 12 to 25 wt % (atro), preferably in a range of 18 to 22% by weight (atro), are incorporated in the thermosensitive recording layer.
• the heat-sensitive recording layer may further contain lubricants and release agents such as metal salts of higher fatty acids, for example, zinc stearate, calcium stearate, etc .; Waxes, for example paraffin, oxidized paraffin, polyethylene, polyethylene oxide, stearamides, castor wax, etc.
• Further constituents of the recording layer are, for example, pigments, preferably inorganic pigments such as, for example, aluminum (hydr) oxide, silicic acid and calcium carbonate, in which case calcium carbonate, which is preferred in from 10 to 18% by weight, based on the total weight of the recording layer, of being incorporated in the recording layer is considered preferable.
• roller coater, knife coater, curtain coater or air brush are particularly suitable as coating apparatus for applying the heat-sensitive recording layer.
• the coating composition used to form the recording layer is aqueous.
• the subsequent drying of the coating composition is usually done by a method in which heat is supplied, as is done by hot-air floating dryer or contact dryer. Proven is also a combination of the listed dry processes.
• the basis weight of the heat-sensitive recording layer is preferably from 2 to 6 g / m 2, and more preferably from 2.3 to 5.8 g / m 2 .
• a pigmented intermediate layer is expediently arranged between the recording layer and the substrate of the heat-sensitive recording material according to the invention.
• the intermediate layer is applied in a preferred embodiment with leveling coating devices, such as, for example, roller coater, doctor blade or doctor blade coaters, the intermediate layer can also make a positive contribution to equalization of the substrate surface, thus increasing the amount of coating material necessarily to be applied to the substrate heat-sensitive recording layer reduced.
• leveling coating devices such as, for example, roller coater, doctor blade or doctor blade coaters
• the intermediate layer can also make a positive contribution to equalization of the substrate surface, thus increasing the amount of coating material necessarily to be applied to the substrate heat-sensitive recording layer reduced.
• For the basis weight of the intermediate layer a preferred range between 5 and 20 g / m 2 and even better between 7 and 11 g / m 2 has proven.
• inorganic oil-absorbing pigments When inorganic oil-absorbing pigments are incorporated in the intermediate layer sandwiched between the recording layer and the substrate, these pigments can absorb the thermoset liquefied wax components of the thermosensitive recording layer in print image formation, thereby promoting still safer and faster operation of the thermally-induced recording, thus such an embodiment preferably applies.
• the pigments of the intermediate layer has an oil absorption of at least 80 cm3 / 100 g, and more preferably 100 cm3 / 100 g, determined according to the Japanese standard JIS K 5101, is having.
• Calcined kaolin has proven particularly useful due to its large absorption reservoir in the cavities.
• the following inorganic pigments are also very well suited as constituents of the intermediate layer: silicon oxide, bentonite, calcium carbonate and aluminum oxide and, in particular, boehmite here. Also mixtures of several different types of inorganic pigments are conceivable.
• the ratio between organic and inorganic pigment is a compromise of the effects caused by the two types of pigments, which is particularly advantageously solved when the pigment mixture to 5 to 30 wt .-% or better to 8 to 20 wt .-% of organic and 95 to 70 wt .-% or better to 92 to 80 wt .-% consists of inorganic pigment.
• Pigment mixtures of different organic pigments are conceivable.
• the pigmented intermediate layer contains at least one binder, preferably based on a synthetic polymer, wherein, for example, styrene-butadiene latex gives particularly good results.
• a synthetic binder with the addition of at least one natural polymer, particularly preferably starch, is a particularly suitable embodiment.
• the proposed recording material when the additional layer containing the non-colored, water-soluble and / or alcohol-soluble solid particles is stamped onto the heat-sensitive recording layer, the proposed recording material preferably has a protective layer, including any indication of a possible authentication feature or its shape to prevent.
• a protective layer for example, coating colors, as they are used in the EP-B-0 909 242 and secondly in the EP-B-1 333 991 be proposed.
• the protective layer combines high environmental resistance with recyclability and good printability in the wet offset process.
• the protective layers mentioned are both relatively cheap to produce and apply in one layer.
• inorganic pigments natural or precipitated calcium carbonate, kaolin or titanium oxide are possible for the protective layer.
• Crosslinking agents for the protective layer are, in particular, cyclic urea, methylolurea, polyamide-epichlorohydrin resin, ammonium zirconium carbonate.
• the protective layer with a basis weight in a range of 1.5 to 6 g / m 2 and especially between 1.8 and 4 g / m 2 , in particular roller coater, doctor blade or (roll) doctor blade coater , but also offer curtain coaters and airbrush application units as coating units for application of the protective layer.
• a protective layer which are curable by means of actinic radiation.
• actinic radiation UV or ionizing radiation, such as electron beams to understand.
• a non-surface treated base paper is to be understood as meaning a base paper which has not been treated in a size press or in a coating device.
• films of, for example, polyolefin and polyolefin-coated papers as a substrate are possible to the same extent, without such an embodiment having an exclusive character.
• a calcined kaolin pigment, styrene-butadiene latex as a binder and, in addition to other aids, starch as cobinder-containing intermediate layer having a basis weight of 9 g / m 2 is applied using a doctor blade.
• a heat-sensitive recording layer having a basis weight of 5.4 g / m 2 is applied by means of a roller doctor coater.
• the aqueous coating used for this purpose contains the following components according to the formulation shown in Table 1: ⁇ u> Table 1: ⁇ / u> Data in wt .-% (atro), based on the total weight of the heat-sensitive recording layer color formers 3-dibutylamino-6-methyl-7-anilinofluoran (ODB-2) 9 color acceptor N- (p-toluensulphonyl) -N'-3- (p-toluensulphonyl-oxyphenyl) -urea according to formula (2), which is Pergafast ® 201 (CIBA) 22 sensitizer Benzylnaphthyl ether (BNE) 22 binder Polyvinyl alcohol (PVA) 7 co-binder Acrylate copolymers 12 methylcellulose 2 pigment calcium carbonate 16
• heat-sensitive recording layer which are not stated in percent and based on the total weight in% by weight (atro) include dispersants, defoamers, optical brighteners, thickeners, waxes and crosslinkers.
• thermosensitive recording layer After drying the thermosensitive recording layer and smoothing the recording material, here a value of 150 Bekk sec is measured, carried out with the aid of a stamp, the application of an aqueous solution to the heat-sensitive recording layer, wherein for the solution, the following components according to the reproduced in Table 2 recipe be used: ⁇ u> Table 2: ⁇ / u> In wt .-% (atro), based on the total weight of the aqueous arginine solution Solid particles Arginine according to formula (1) 4 wetting agent Olfin 0.5 binder polyvinyl alcohol 1
• the heat-sensitive recording material is placed for 2 min in a drying oven at 120 ° C heat.
• the heat causes blackening of the heat-sensitive recording layer as a result of the color-forming reaction of color former and color acceptor, but this blackening does not occur in sharp-edged places where the aqueous arginine solution had previously been applied.

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• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Heat Sensitive Colour Forming Recording (AREA)

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Citations (7)

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• 2006
  • 2006-11-24 DE DE200610056003 patent/DE102006056003B4/de not_active Expired - Fee Related
• 2007
  • 2007-11-22 EP EP07121262.5A patent/EP1925459B1/fr not_active Not-in-force

Patent Citations (7)

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