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
  • B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
• • 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
  • B41M5/30—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 present invention relates to a heat-sensitive recording material having a substrate and at least one heat-sensitive recording layer, the recording layer obtained from a coating composition containing dye precursors and at least one color developer, wherein dye precursors and the at least one color developer react with each other under the action of heat to form color in the form of a printed image react.
• thermosensitive recording material having, as a first security feature in the form of a spurious watermark, a latent image printed on the back surface of the recording material, which is produced by means of a security ink containing a fluorescent reagent.
• the security ink contains a water-repellent agent.
• the fluorescent ink containing the fluorescent reagent and the water repellent-containing security ink is contained or dispersed in an aqueous vehicle which may contain a binder other than these components.
• the object of the present invention is to provide a heat-sensitive recording material with a new authenticity-proofing security feature, which can be realized simply and without any additional measures within the production process and which, if possible, can not be recognized by simple visual inspection.
• the invention provides that the, the recording material according to the invention authenticated completely unambiguously color of the heat-induced print image of at least two, most preferably composed of exactly two colors, which are set in an appropriate relationship to each other. These two colors, usually black and blue, are formed when, by the action of heat, both the first substance as dye precursor and the second substance as dye precursor react with the at least one color developer.
• dye precursors are contained in a range of 5 to 9% by weight, more preferably in a range of 6 to 8% by weight, in the formed heat-sensitive recording layer.
• a ratio of 1: 3 to 9: 1 of the first substance to the second substance is recommended.
• an average particle size in a range from greater than 0.3 ⁇ m to a maximum of 1.5 ⁇ m, in particular from 0.45 ⁇ m to 0.9 ⁇ m, is recommended.
• the limits are given upwards by a too low sensitivity and down by an otherwise too strong inclination of the heat-sensitive recording material for graying.
• the recording layer coating composition it is preferable to use a mixture of 2,2-bis (4-hydroxyphenyl) propane, which is bisphenol-A, and a urea-urethane compound represented by the above formula, wherein bisphenol-A is in the range of 20 to 23 wt .-% and the urea-urethane compound in a range of 3 to 6 wt .-%, each based on the total weight of the recording layer, are involved in this layer.
• the coating composition for forming the thermosensitive recording layer preferably also contains sensitizers having a melting point, ideally from 60 ° C to 180 ° C, more preferably having a melting point of from 80 ° C to 140 ° C, to increase 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 coating composition for the heat-sensitive recording layer are, for example, water-soluble binders such as starch, hydroxyethylcellulose, methylcellulose, carboxymethylcellulose, gelatin, casein, polyvinyl alcohols, modified polyvinyl alcohols, sodium polyacrylates, acrylamide-acrylate copolymers, acrylamide-acrylate-methacrylate terpolymers, alkali metal salts of styrene-maleic anhydride copolymers or ethylene-maleic anhydride copolymers, etc .; Water-insoluble latex binders such as styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, methyl acrylate-butadiene copolymers, etc.
• water-soluble binders such as starch, hydroxyethylcellulose, methylcellulose, carboxymethylcellulose, gelatin, casein, polyvinyl alcohols, modified polyvinyl
• modified polyvinyl alcohol is considered to be a particularly preferred binder which, based on the total weight of the recording layer, is incorporated in a range of 9 to 13% by weight in the heat-sensitive recording layer formed.
• the coating composition for forming the heat-sensitive recording layer may further contain slip 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, in which case in particular calcium carbonate, preferably in an amount of from 20 to 27% by weight, is preferred based on the total weight of the recording layer to be incorporated in the recording layer.
• coloring contains the coating composition for forming the recording layer for both of the embodiments disclosed herein, one or more dyes, e.g. B. Pergasol Red 2B.
• 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 novel recording material.
• 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 wax components of the thermosensitive recording layer liquefied by heat of the thermal head in the typeface formation, thus promoting still safer and faster operation of the heat-induced recording.
• Preferred inorganic pigments of the intermediate layer are those selected from the group comprising natural and calcined kaolin, silica, bentonite, calcium carbonate and aluminum oxide, in particular boehmite here.
• calcium carbonate is particularly preferred. Also mixtures of several different types of inorganic pigments are conceivable.
• the particle size of the inorganic pigments present in the intermediate layer is preferably in a range of less than 2 ⁇ m. Pigments which have a particle size distribution of from 34 to 40% by weight of less than 1 ⁇ m and from 57 to 63% by weight of less than 2 ⁇ m have proved to be advantageous.
• the quantitative ratio between organic and inorganic pigment is a compromise of the effects brought about by the two types of pigment, which is achieved particularly advantageously if the pigment mixture contains 15 to 50% by weight or better, 20 to 50% by weight of organic and 85% by weight to 50% by weight or better to 80 to 50% by weight of inorganic pigment. It is very particularly preferred if the pigment mixture consists of 25 to 40% by weight of organic and 75 to 60% by weight of inorganic pigment.
• the organic pigments have a wall of thermoplastic resin which preferably comprises (meth) acrylonitrile copolymer, polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene acrylate, polyacrylonitrile or polyacrylic acid ester. 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 admixture of at least one natural polymer, particularly preferably starch, represents a particularly suitable embodiment.
• a binder-pigment ratio within the pigmented intermediate layer between 3: 7 and 1: 9, in each case based on wt .-%, a particularly suitable embodiment is present.
• paper and especially a non-surface treated base paper is preferably in a range for the basis weight between 45 and 130 g / m 2 substrate, which is also in the market with regard to the good environmental performance due to the Good recycling ability has prevailed and is preferred for the purposes of the invention.
• a non-surface-treated coated paper is to be understood as a paper which has not been treated in a size press or in a coating device.
• a non-surface-treated basecoated base paper with an inorganic pigment, in particular calcium carbonate is considered suitable in the composition.
• 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 non-surface-treated base paper of 82 g / m 2 is used, to which a pigmented intermediate layer of 8 g / m 2 is applied by means of a doctor blade device.
• the intermediate layer mainly comprises calcium carbonate as an inorganic pigment, organic hollow body pigments and as a binder a mixture of styrene-butadiene latex with the addition of a small amount of starch.
• the pigmented intermediate layer is a ratio of the binder content (styrene-butadiene latex + starch) to the pigment content (calcium carbonate + hollow body pigments) of 1: 3.5 and further a ratio of the organic hollow body pigments to calcium carbonate of 3: 7 set, in each case based on wt .-% of the individual components in the pigmented intermediate layer.
• Example 2 unit example 1
• Example 2 Example 3
• thermosensitive recording materials prepared in the context of the invention examples meet the object underlying the invention very well, the set and reproducible measurable color locations for the recording layer on the one hand and for the formed by heat pressure image on the other hand are authenttechnischsnach undd, without this in terms of print image previously by simple in Visual inspection can be seen.

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

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Citations (3)

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• 2006
  • 2006-07-12 DE DE102006032523A patent/DE102006032523A1/de not_active Withdrawn
• 2007
  • 2007-01-18 EP EP07000997A patent/EP1813436A3/fr not_active Withdrawn

Patent Citations (3)

Non-Patent Citations (1)

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