Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
  • G03G7/0006—Cover layers for image-receiving members; Strippable coversheets
  • G03G7/002—Organic components thereof
  • G03G7/0026—Organic components thereof being macromolecular
  • G03G7/004—Organic components thereof being macromolecular obtained by reactions only involving carbon-to-carbon unsaturated bonds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M3/00—Printing processes to produce particular kinds of printed work, e.g. patterns
  • B41M3/14—Security printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M7/00—After-treatment of prints, e.g. heating, irradiating, setting of the ink, protection of the printed stock
  • B41M7/0027—After-treatment of prints, e.g. heating, irradiating, setting of the ink, protection of the printed stock using protective coatings or layers by lamination or by fusion of the coatings or layers

Definitions

• the present invention relates to a print, more particularly to a tamperproof identification document.
• Identification documents essentially comprise a card or sheet material containing information retaining to the bearer. Generally a portion of the information is in the form of a photograph.
• Identification cards I.D. cards
• I.D. cards are used e.g. to establish a person's authorization to conduct certain activities (driver's licence) or the authorization to have access to certain areas(employee I.D. cards) or to engage in credit transactions (I.D. credit cards).
• I.D. cards In view of the widespread use of I.D. cards, especially in commercial transactions such as cashing checks, credit purchases, etc., it is important that the information contained in the I.D. card cannot be altered and that the I.D. card gives maximum protection against counterfeiting by alteration and/or replacement of its data and photograph.
• a method for preparing a security document comprising the step of printing with a laser printer on an imaging element comprising a support and a toner accepting layer, characterized in that said toner accepting layer is a layer comprising a copolymer of ethylene and acrylic acid.
• a toner accepting layer in the present disclosure is every layer capable of accepting toner from laser color printing equipment.
• Said toner may be a black toner but is preferably a color toner.
• said toner accepting layer is a layer comprising a copolymer of ethylene and acrylic acid.
• Preferably said layer is a layer comprising at least 80 % by weight of said copolymer, more preferably said layer consist of said copolymer.
• a copolymer of ethylene and acrylic acid according to the invention comprises preferably between 10% and 50 % by weight of acrylic acid, more preferably between 13 % and 35 % by weight of acrylic acid, most preferably between 17 % and 25 % by weight of acrylic acid.
• a copolymer of ethylene and acrylic acid according to the invention has preferably a melt index between 100 and 10000, more preferably a melt index between 300 and 3000.
• a copolymer of ethylene and acrylic acid according to the invention has preferably a weight average molecular weight between 10000 and 100000, more preferably between 15000 and 30000.
• a copolymer of ethylene and acrylic acid according to the invention is preferably used at a pH between 3 and 10, more preferably at a pH between 6 and 9.
• a solution or dispersion of a copolymer according to the invention is completely or partially neutralized with an alkali base or buffer salt or more preferably with ammonia.
• Copolymers of ethylene and acrylic acid are commercially available under the name of PRIMACOR from Dow Chemicals, Michigan, USA.
• a toner accepting layer according to the invention is preferably present in a weight between 0.5 g/m 2 and 30 g/m 2 , more preferably between 1.0 g/m 2 and 15 g/m 2 , most preferably between 2.0 g/m 2 and 8.0 g/m 2 .
• the support in accordance with the invention is preferably a flexible support.
• Said flexible support can be transparent or opaque.
• the opaque support is e.g. an opaque paper support or resin coated paper support, e.g. polyolefin coated paper and polyethylene coated paper of which the polyethylene layer may contain opacity providing pigments such as white TiO 2 particles as described e.g. in EP-A 324 192.
• Preferably security paper is used.
• opaque supports that may be used are resin supports containing in their resin mass dispersed white pigments, e.g. TiO 2 , or are such resin supports that contain said pigments dispersed in the resin mass in the presence of light-straying microvoids as described e.g. in EP 349152.
• Organic resins used for manufacturing said supports e.g.
• polycarbonate e.g. poly(ethylene terephthalate) or poly(ethylene naphthalate), poly (methylacrylaat-styrene-acrylonitrile), poly (acrylonitrile-butadiene-styrene), polyamides, polyethersulfones, polyetherketones, polystyrene, poly-Alpha-olefins such as polypropylene or polyethylene, polyvinyl acetals and homo- and copolymers of vinyl chloride.
• cellulose esters e.g. cellulose triacetate.
• Transparent or translucent supports may be transparent or translucent organic resins e.g. the resins cited above.
• Preferred transparent or translucent supports are films of polyesters such as poly(ethylene terephthalate) or of poly-Alpha-olefins such as polyethylene.
• the toner accepting layer may be present contiguous to the support.
• layers present between the toner accepting layer according to the invention and the support can be subbing layers to improve the adhesion between the support and the toner accepting layer.
• Such layer can also be an information carrier, at least part of the information being present in the toner image receiving layer. It is required when said imaging element is used as a security document to laminate said imaging element either by laminating a laminating foil against the support of the imaging element or by providing a laminating foil at one outer side of the imaging element and another laminating foil at the other outer side of the imaging element and laminating these laminating foils together.
• a security document according to the invention comprising a toner accepting layer comprising a copolymer of ethylene and acrylic acid an effective security seal is easily made between the toner accepting layer and a laminating foil when a laminating foil is laminated to the toner accepting layer.
• One laminating foil can be a single layer of an organic resin e.g. a polyethylene, a polypropylene film or a polyester film.
• an organic resin e.g. a polyethylene, a polypropylene film or a polyester film.
• a laminating foil has preferably a thickness of only 0.050 to 0.200 mm.
• a sheet of that thickness can still be manipulated easily in a mechanical printing process, e.g. offset or intaglio printing, and can receive security or verification marks in the form of e.g. a watermark, finger prints, printed patterns known from bank notes, coded information, e.g. binary code information, signature or other printed personal data or marks that may be applied with livid crystals, fluorescent pigments, nacreous pigments giving special light-reflection effects, and/or visibly legible or ultraviolet-legible printing inks as described e.g. in GB-P 1,518,946 and US-P 4,105,333.
• At least one of the laminating foils and optionally both of the laminating elements comprises an outer resin layer and an inner resin layer.
• inner resin layer of a laminating element comprising an inner and an outer resin layer is meant the resin layer which after lamination is nearest to the toner accepting layer.
• outer resin layer is then the layer of said laminating element which after lamination becomes an outside layer of said security document.
• Said outer resin layer can be any transparent or translucent organic resin e.g. cellulose acetate film, poly(vinyl acetal) film, polystyrene film, polycarbonate film or polyvinyl chloride film.
• said outer resin layer is a poly(ethylene terephthalate) film, more preferably an oriented poly(ethylene terephthalate) film.
• Said inner resin layer can be any transparent or translucent melt-adhesive layer comprising an organic resin having a lower glass transition temperature (T g ) and melting temperature (T m ) than the outer resin layer.
• T g glass transition temperature
• T m melting temperature
• the glass transition temperature of the resin comprised in the inner resin layer is at least 20°C, more preferably at least 40°C lower than the glass transition temperature of the resin comprised in the outer resin layer.
• Most preferably said inner resin layer is a polyalkylene layer, particularly preferably a polyethylene layer.
• Tg values of polyethylene, polypropylene, polyvinyl chloride and polyethylene terephthalate being -20°C, +5°C, +80°C and +67°C respectively (see J.Chem. Educ., Vol. 61, No. 8. August 1984, p. 668).
• the toner accepting layer is coated on a laminating foil which after the generation of information on or in the toner accepting layer can be laminated to a support, preferably a flexible opaque support, most preferably paper such as security paper.
• the optical information can be partly applied directly on the support of the information carrier by printing techniques.
• Suitable printing processes are e.g. planographic offset printing, gravure printing, intaglio printing, screen printing, flexographic printing, relief printing, tampon printing, ink jet printing, laser printing, thermal transfer printing, dye diffusion thermal transfer printing and toner-transfer printing from electro(photo)graphic recording materials.
• security or verification marks in the form of e.g. a watermark, finger prints, printed patterns known from bank notes, coded information, e.g. binary code information, signature or other printed personal data or marks or layers that may be applied with liquid crystals, fluorescent pigments, nacreous pigments giving special light-reflection effects, and/or visibly legible or ultraviolet-legible printing inks as described e.g. in GB-P 1,518,946 and US-P 4,105,333.
• security or verification marks in the form of e.g. a watermark, finger prints, printed patterns known from bank notes, coded information, e.g. binary code information, signature or other printed personal data or marks or layers that may be applied with liquid crystals, fluorescent pigments, nacreous pigments giving special light-reflection effects, and/or visibly legible or ultraviolet-legible printing inks as described e.g. in GB-P 1,518,946 and US-P 4,105,333.
• the image on said imaging element is at least partially generated in or on the toner accepting layer by exposure of the imaging element to a laser printer, preferably a color laser printer followed by a fixation, preferably a thermal fixation of the obtained image.
• imaging element I comparative imaging element
• a 65 ⁇ m thick transparent polyethylene therephthalate film is coated with a layer comprising 0.5 g/m 2 of gelatine and a latex of polyester-polyurethane at 400 mg/m 2 of solid product. Thereon was coated a layer containing 0.7 g/m 2 of carboxymethylcellulose, 1.4 g/m 2 of gelatine, 3.10 -3 mmole/m 2 of silver sulphide nuclei, 18.10 -3 mmole/m 2 of nickel sulphide nuclei and 1.7g/m 2 of a nacreous pigment. On top of said layer is coated a layer containing 0.5 g/m 2 of gelatine.
• imaging element II imaging element according to the invention
• a 65 ⁇ m thick transparent polyethylene therephthalate film is coated with a layer comprising 0.35 g/m 2 of gelatine, 1,50 g/m 2 of a nacreous pigment and 3.4 g/m 2 of a copolymer of ethylene and acrylic acid (7:1). On said layer was coated a layer comprising 4 g/m 2 of a copolymer of ethylene and acrylic acid (7:1).
• said paper support can be delaminated from the imaged element without damage to the support in the case of imaging element I while there is serious damage to the support in the case of imaging element II.

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Citations (5)

• 1997
  • 1997-11-18 EP EP19970203597 patent/EP0845711B1/fr not_active Expired - Lifetime

Patent Citations (5)

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