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
  • B41M5/40—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
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
  • G09F3/00—Labels, tag tickets, or similar identification or indication means; Seals; Postage or like stamps
  • G09F3/02—Forms or constructions
• • 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
  • B41M2205/40—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
  • B41M5/40—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
  • B41M5/44—Intermediate, backcoat, or covering layers characterised by the macromolecular compounds

Definitions

• the invention relates to a heat-sensitive recording sheet with a Substrate, a heat-sensitive recording layer containing color formers and color acceptors and a protective layer formed on the recording layer, which as a binder is a water-insoluble, self-crosslinking acrylic polymer, a crosslinking agent and contains as a pigment an alkaline bentonite, as well as its Use as a ticket.
• a binder is a water-insoluble, self-crosslinking acrylic polymer, a crosslinking agent and contains as a pigment an alkaline bentonite, as well as its Use as a ticket.
• a heat recording sheet of the type mentioned is known from WO 97-18091 A 1 and also from WO 98-43824 A 1 .
• the protective layer of the known heat recording sheet contains not only water-insoluble but also water-soluble binder.
• a pigment content of 12 to 20% by weight is to be provided, which can consist predominantly of alkaline digested bentonite
• the pigment content of the protective layer according to the teaching of the second document is between greater than 20 and 40% by weight. , 15 to 30% by weight of bentonite, in particular of an alkaline digested bentonite.
• a crosslinking aid can be contained in the protective layer, the proportion of which, based on the total weight of the protective layer, is 1 to 2% by weight in the case of the first document and 1 to 5% by weight in the case of the second document is.
• a protective layer is known from US-A-4,682,192 which serves to protect a heat-sensitive recording layer applied to a substrate.
• the protective layer contains a colloidal inorganic silicate, which is incorporated either in the absence or in a mixture with a water-soluble or very poorly water-soluble high molecular compound.
• the colloidal inorganic silicate is selected from colloidal magnesium aluminum silicates and fluorine-containing colloidal magnesium silicates, bentonite, attapulgite and dimonite being disclosed in particular. Further references to special properties of the silicates are not disclosed in the writing.
• Self-crosslinking acrylic polymers are proposed as poorly water-soluble high-molecular compounds.
• the mixing ratio of the said silicates and the sparingly water-soluble high molecular weight polymers is generally in the range between 1: 0.1 and 1:10, a ratio between 1: 1 and 1: 5 being given as the preferred range.
• a protective layer is known from EP-A-0 344 705 , in which 0.5 to 3 parts by weight of pigment are present per part by weight of binder.
• Suitable binders for the protective layer include polyvinyl alcohol, carboxymethyl cellulose, starch and starch derivatives and copolymer emulsions of styrene-butadiene, vinyl acetate-ethylene, vinyl acetate-vinyl chloride-ethylene and methacrylate-butadiene.
• Precipitated calcium carbonate, ground calcium carbonate, talc, kaolin, silicon dioxide anhydride, magnesium carbonate, zinc oxide, aluminum oxide and aluminum hydroxide in addition to organic pigments are mentioned as suitable pigments.
• Protective layers containing pigment, which only contain water-soluble binder, are described as examples.
• EP-B-0 373 903 relates to a heat-sensitive recording paper with an internal adhesive strength of 2.5 kg.cm or more, which has a protective layer with a smoothness of at least 500 Bekk seconds, preferably from 700 to 1500 Bekk seconds, on a fine particle of a styrene-acrylate polymer and an intermediate layer containing a binder is applied.
• Suitable binders for the protective layer are both water-soluble and water-insoluble high polymers with sufficient film-forming capacity. Any pigment addition to the protective layer is also disclosed, but there is no indication in the document of the nature of the suitable pigments.
• the new recording sheet must be distinguished by a high level of environmental resistance, which in the sense of the invention means the outstanding resistance of the heat-sensitive recording sheet to water and to plasticizers.
• An essential aspect of the new recording sheet must be its cost-effective production method.
• Another object of the invention is to develop a recording sheet which, in addition to the range of requirements mentioned above, has good validability and good printability in the flexographic and wet offset printing processes, at least on its side provided with the heat-sensitive recording layer.
• a heat-sensitive recording sheet has good validity in the sense of this invention, if one consisting of coloring pigments, not solvent-based stamping ink immediately after printing, neither dry nor can be wiped completely wet from the recording sheet.
• water-insoluble binders used in the description and claims means those which are in the form of aqueous dispersions / latices of polymers or copolymers. Crosslinking agents are not included in the binders in the context of the present invention.
• the basis of the new recording sheet is the highly cleaned alkaline one Bentonite, as an inorganic pigment alone or in the mixing ratio according to the invention with other inorganic pigments in the protective layer.
• the Self-adhesion of this bentonite requires a completely new composition of the protective layer, which differ in the ratio of binder to pigment and crosslinking agent according to the invention precipitates to binders.
• the choice of binder comes into play meaning essential to the invention than only by reaching for a self-cross-linking Acrylic polymer as the sole binder and used in a certain ratio with pigment on the one hand and crosslinking agent on the other hand the production of a recording sheet succeeds after its smoothness adjustment according to the invention meets all required technological requirements.
• acrylic polymer is to be understood as a self-crosslinking binder, selected from the group comprising styrene-acrylic acid ester copolymer Copolymer of styrene / acrylic acid ester containing acrylamide groups and preferred a copolymer based on acrylonitrile, methacrylamide and acrylic ester.
• the Smoothing the new recording sheet by treating it with a smoothing device, for example, a calender. Due to the fact that the protective layer of the new recording sheet is formed in one layer, the subject of the invention also meet the required economic conditions.
• the recording sheet according to the invention has a pigment portion in the protective layer which, owing to the choice of the highly purified alkaline bentonite as pigment, makes the new recording sheet relatively protective even with protective layers
• Area-related mass guarantee both good devaluability and good printability, which can be explained, among other things, by the large inner surface and the large micropore volume of the highly purified alkaline-processed bentonite.
• a series of experiments showed that natural or precipitated calcium carbonate, kaolin or titanium oxide also make a positive contribution to improving the absorption of printing and stamping ink, but the total proportion of bentonite compared to the other inorganic pigments must not be less than 80% by weight.
• the positive influence of aluminum oxide and aluminum-modified silica on the printing and stamp ink absorption could also be demonstrated, provided that the total proportion of bentonite compared to the other inorganic pigments does not fall below 80% by weight.
• Crosslinking agent is more than 5 wt .-% bundling agent furthermore, a high level even with protective layers with a relatively low area-related mass Given the new sheet's environmental resistance.
• the bentonite in powder form has an area-edge ratio in a range between 15 and 70, in particular in a range between 20 and 50.
• the crosslinking agent / binder ratio is in a range between 1: 5 and 1:40, preferably in a range between 1: 5 and 1:20 or even better in a range between 1: 5 and 1:10, whereby particularly favorable test results were found with a crosslinking agent / binder ratio in a range between 1: 5 and 1: 7.
• the protective layer Based on a smoothness of the protective layer of at least 900 Bekk seconds a further increase in barcode readability in the recording sheet according to the invention, if the protective layer becomes smooth in one area due to strong calendering from 1200 to 5500 Bekk seconds.
• the protective layer is smooth in one Has a range greater than 1500 to 2500 Bekk seconds, as well as excellent Barcode readability and compliance with all other technological and economic Demands also a pleasant and particularly even appearance of the new heat-sensitive recording sheet.
• the aim is to form the cover layer with the smallest possible area-related mass, but at the same time the contradictory requirements of high environmental resistance as well as good devaluability and good printability in flexo and wet Offset printing processes are to be fulfilled. While the high level of environmental resistance requires a top layer with the largest possible area-related mass and high binding and crosslinking agent content, the demand for good devaluability and printability is aimed at a top layer with the largest possible area-related mass and high pigment content, which above all contradicts good barcode readability.
• a recording sheet which meets all the requirements ideally has a mass per unit area of the protective layer in a range from 1.0 to 4.0 g / m 2 , preferably in a range from 1.5 to 3.0 g / m 2 and very particularly preferably in a range from 1.8 to 2.5 g / m 2 .
• the specified protective layers can be heat-sensitive recording layers can be applied directly to the substrate
• the substrate and the heat-sensitive recording layer can be preferred according to one Embodiment also applied to such heat-sensitive recording sheets in which between the substrate and the heat-sensitive recording layer still an intermediate layer is formed, which is preferably oil-absorbent contains inorganic pigment.
• an intermediate layer can be a positive one Contribute to the leveling of the substrate surface, which increases the amount necessary coating color for the heat-sensitive recording layer reduced
• the pigments of this intermediate layer take the wax components of the heat-sensitive recording layer liquefied by the action of heat in the formation of typefaces and thus favor a safe and Fast functioning of the heat-induced recording.
• the recording sheet according to the invention preferably has a backside coating which is applied to the substrate side which is opposite to the side provided with the heat-sensitive recording layer.
• a backside coating is proposed, for example, in DE-A-197 48 258 and then serves to improve the printability of the recording sheet on the backside in the offset and flexographic printing process and to improve the blocking effect of the backside against plasticizers, oils and greases.
• a pigmented intermediate layer which is designed in accordance with a proposal of the as yet unpublished DE 100 21 896 for the formation of authenticity-proofing markings in locally different thicknesses, offers itself as a security feature for the new recording sheet.
• the protective layer be the metal salt of a long chain fatty acid, especially stearic acid, contains as a lubricant.
• a zinc stearate is preferably used as a lubricant in the protective layer Amount less than 20, in particular less than 15 parts by weight, based on a total of 100 Parts by weight of the protective layer.
• the protective layer is produced using an aqueous coating slip, in addition to the pigments, binders, crosslinking agents and Lubricants still contains conventional coating aids and additives, such as. B. dispersants, Defoamers and metal salts to accelerate the crosslinking of the crosslinking agents with a lot of these coating aids of no more than together 10 parts by weight, preferably not more than 7 parts by weight, based on the total 100 parts by weight of the protective layer.
• a paper web made of bleached and ground hardwood and softwood cellulose with a mass per unit area of 67 g / m 2 is added to the substrate on a Fourdrinier paper machine with the addition of conventional admixtures in customary amounts.
• a calcined kaolin as a pigment, styrene-butadiene latex as a binder and starch as a cobinder are applied to the front in addition to an additional intermediate layer of 8 g / m 2 .
• a heat-sensitive recording layer containing color formers and color acceptors and having a mass per unit area of 5.4 g / m 2 is applied to the intermediate layer.
• a protective layer of 2 g / m 2 is applied to the dried recording layer.
• the pigment used is a highly purified, alkaline-processed bentonite with a platelet structure, the inherent adhesion of which enables it to be fixed with little need for binding agents, and the specific surface area of which, in the non-dispersed state, is given as 85 m 2 / g with an area-to-edge ratio which is in powder form Bentonite is in a range between 20 and 50.
• a binder / pigment ratio of 6: 1 and a crosslinking agent / binder ratio of 1: 5 are set.
• Polyamide-epichlorohydrin resin is used as the crosslinking agent, and the aqueous dispersion of a self-crosslinking copolymer of acrylonitrile, methacrylamide and acrylic ester is used as the binder.
• the coating slip for the production of the protective layer contains, as further components, a defoamer, stearic acid as a lubricant and various dispersants, on the one hand for the pigment and on the other hand for the lubricant.
• the applied coating slip is dried and the recording sheet produced so far smoothed using a calender, with a smoothness of 2200 Bekk seconds is achieved.
• the recording sheet produced in this way which is inexpensive to produce compared to its requirement profile, can be printed well in the flexographic and wet offset printing processes and has good devaluability.
• the water resistance is recorded as the ratio of two measurements of the dynamic pressure density determined using the Macbeth RD 914 from Karl Schröder KG (Korrillonstrasse 32, D-69469 Weinheim).
• a sample of the recording sheet according to the invention is provided with a typeface using a TP 3000-300 thermal printer from Charles Richiger AG, Mechanical Engineering (Bernstrasse 81, CH-3613 Steffisburg). After a first measurement of the dynamic printing density, the sample of the recording sheet according to the invention is immersed in water for 60 minutes.
• the dynamic print density is then measured a second time.
• the water resistance of the recording sheet according to the invention examined in this way can be described as very good given a quotient of both measured values of 94%.
• the new recording sheet receives a heat-induced barcode using a 300dpi BOCA printer, type Micro 21 from Boca tickets & printers (Vlietweg 17, NL-2266 KA Leidschendam).
• the printed image is viewed visually and rated good in terms of sharpness and color density.

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• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Heat Sensitive Colour Forming Recording (AREA)
• Paper (AREA)
• Credit Cards Or The Like (AREA)

Applications Claiming Priority (3)

Publications (2)

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Country Status (8)

Cited By (1)

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• 2000
  • 2000-10-16 DE DE10051294A patent/DE10051294C1/de not_active Expired - Fee Related
• 2001
  • 2001-10-09 JP JP2002535898A patent/JP2004526586A/ja active Pending
  • 2001-10-09 ES ES01983538T patent/ES2227302T3/es not_active Expired - Lifetime
  • 2001-10-09 DE DE50103351T patent/DE50103351D1/de not_active Expired - Lifetime
  • 2001-10-09 WO PCT/EP2001/011677 patent/WO2002032688A1/de active IP Right Grant
  • 2001-10-09 CN CNB018190499A patent/CN1211217C/zh not_active Expired - Fee Related
  • 2001-10-09 US US10/399,191 patent/US20060154819A1/en not_active Abandoned
  • 2001-10-09 EP EP01983538A patent/EP1333991B1/de not_active Expired - Lifetime
  • 2001-10-09 AT AT01983538T patent/ATE273800T1/de not_active IP Right Cessation
• 2007
  • 2007-11-29 US US11/998,246 patent/US20080081764A1/en not_active Abandoned

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