Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
  • D21H21/40—Agents facilitating proof of genuineness or preventing fraudulent alteration, e.g. for security paper
• • 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
  • B41M3/144—Security printing using fluorescent, luminescent or iridescent effects

Definitions

• the invention relates to a printable sheet for manufacturing security documents comprising a security means against counterfeiting by reproduction with photocopiers, in particular color photocopiers or by scanner and / or authentication means.
• This security means is an iridescent coating partially or totally disposed on the surface of the sheet, an impression on this iridescent coating being achievable, the holding of this impression being good and its print rendering being high.
• the invention relates more particularly to sheets of paper for banknotes or other valuable securities which can in particular be printed by offset printing and / or by intaglio printing. It further relates to a composition which simultaneously gives it surface iridescence properties, resistance to circulation and possibly of superior printability.
• security documents for example papers for banknotes or for checks or any other security of value include chemical means of authentication and / or indicators of falsification. Some contain surface or bulk substances preventing reproduction of the document by photocopy or scanner.
• a security paper comprising an iridescent substance as a security means.
• This iridescent substance can be deposited on the surface of the paper by printing or by coating an ink made with this iridescent substance and a binder.
• iridescent substance gives particular optical effects, in particular changes in reflections, tints or shades depending on the angle of observation.
• a first drawback is that during the printing of the sheet, in particular by intaglio printing, there may be a more or less significant transfer of the layer of iridescent substance on the intaglio plates.
• a second drawback of the sheets of the prior art is that the iridescent layer does not resist all the mechanical actions which could alter it.
• the security documents produced from these sheets circulate between individuals and pass through various machines, for example false document detectors, vending machines, etc.
• the documents are subjected to treatments liable to deteriorate them, for example they are folded, crumpled, wet, scraped, subjected to various rubs and can even undergo a washing treatment by introduction into a washing machine.
• a printable sheet usable for manufacturing security documents having a print rendering and a high resistance to circulation such that at least one of its faces is treated with a composition comprising at least one filler. and at least one binder.
• a composition does not contain an iridescent substance.
• the print rendering is the fact that the line obtained by printing is perfectly clear, that is to say that it does not contain burrs or in terms used by the skilled person, "feathering". These burrs are formed by bulges more or less perpendicular to the line, which means that the size of the line is greater than the desired thickness and this results in it being difficult to bring the lines together without risk of blurring. Therefore, the central bank that prints the paper to obtain security documents is forced to make sufficiently fine prints. It is therefore difficult to produce micro-prints. However, micro-prints are very useful as security elements because they are difficult to reproduce by photocopiers who currently cannot reproduce very fine prints. Print rendering is also characterized by the density of print color.
• the human eye has sufficient resolution to distinguish between an impression having a good rendering and an impression comprising a "feathering".
• one of the objects of the invention is to provide a non-reproducible security document in particular by color photocopying or by scanner, comprising at least partially a surface coating obtained from an iridescent composition, such that no transfer of the iridescent coating does not take place when the document is printed.
• Another object of the invention is to provide a security document above such that the iridescent coating itself has good resistance to circulation.
• a third object of the invention is to provide a security document comprising at least partially an iridescent coating making it possible to maintain the good resistance to circulation (that is to say good behavior) of the surface impressions made on this coating of this iridescent composition.
• Another object of the invention is to provide a security document having a good print rendering.
• the technical problem which must therefore be resolved is to provide an iridescent composition which can be easily carried by any coating or printing means on a sheet so that the iridescent effect is retained when the sheet is coated with the composition and at the same time it is possible to print on this coating by obtaining good printing results and that the circulation resistance of the printed sheet is good.
• the objects of the invention are achieved by using as an iridescent composition a mixture comprising at least one iridescent pigment and at least one binder, the binder being chosen so as not to mask the iridescent effect of the substance.
• the invention relates to a printable security sheet comprising a security means against counterfeiting by reproduction with a photocopier or a scanner, and / or as an identification means, at least one iridescent coating disposed at least partially on the surface of the sheet, said coating having good resistance to circulation and being obtained from a composition consisting of at least one binder and at least one iridescent substance.
• the binder is chosen from polyurethanes, halogenated polymers and more preferably from homo- or co-polymers of alkene halide, ketene halide, and mixtures thereof.
• poly (vinyl chloride) is chosen.
• the binder can contain a plasticizer which can, for example, be a vegetable oil.
• the binder may also contain a siccative.
• the iridescent substance can for example be an inorganic pigment such as a mica coated with titanium dioxide, a plastic pigment composed of a special stack of films producing an iridescent (or dichroic) effect when the pigment is observed from a certain angle.
• an inorganic pigment such as a mica coated with titanium dioxide
• a plastic pigment composed of a special stack of films producing an iridescent (or dichroic) effect when the pigment is observed from a certain angle.
• additives such as viscosity modifiers, rheology agents, plasticizers, etc. can be added to the iridescent composition.
• the iridescent composition is preferably deposited on the surface of a sheet, in an amount of 3 to 12 g / m2.
• This composition can be deposited by any coating or printing means on the surface of the document. It can be deposited for example by air layer coating, at the MEYER bar, by gravure printing, by screen printing, etc. It can be carried out in a solvent or aqueous medium.
• the security document can be a sheet made from cellulosic and / or synthetic fibers, possibly mixed with mineral fibers.
• the document may possibly be a film or a plate made of synthetic material. It may include other security elements.
• the tests are estimated visually (with the naked eye or with a magnifying glass) and by comparison.
• a part of the sheet which has not been treated is compared with a part treated with the iridescent composition according to the invention.
• the sheet is printed by offset or intaglio.
• the resistance to circulation is observed on the one hand from the parts treated according to the invention and on the other hand from the untreated parts. It can be seen that the print rendering on the treated parts is greater than that of the untreated parts.
• the document cannot be reproduced by photocopy.
• Circulation resistance tests (wrinkling and friction) are described in the article: WARING QUALITY OF EXPERIMENTAL CURRENCY-TYPE PAPERS, Journal of Research of the National Bureau of Standards, Volume 36, pages 249 to 268, March 1946.
• the document is subjected to a prior crumpling. Then place it in a bottle, as above, but add powder containing the dyes and an artificial sweat composition.
• a sheet is produced on a paper machine from an aqueous suspension of cellulose fibers, optionally in admixture with synthetic fibers and other additives used in stationery.
• composition is deposited at a rate of 8 g / m2 dry.
• the area of the sheet coated with the iridescent composition does exhibit a yellow green iridescence effect, that is to say that if we look at the sheet at an angle substantially perpendicular to the sheet, the coated area appears substantially white. and if we look at the sheet at an angle of about 45 degrees, the coated area appears yellow green.
• Example 1 is repeated, but an iridescent substance is used, a mica coated with titanium dioxide giving a pink iridescence.
• the area of the sheet coated with this composition does have a pink iridescence effect.
• the sheets obtained according to Examples 1 and 2 are printed by intaglio and they are subjected to the circulation resistance tests mentioned above, after drying of the intaglio ink.
• the printing result in particular the fineness of the lines, is greater on the part comprising the iridescent composition than that obtained on the non-iridescent part.
• Example 1 If a composition such as that mentioned in Example 1 is produced, but by replacing the binder with a polyvinyl acetate derivative, then this composition is deposited on a sheet of paper and only after drying an intaglio printing is carried out, an iridescent composition is transferred to the intaglio printing plates.
• Example 2 An iridescent composition like that of Example 1 is produced, but the binder is replaced by a binder based on nitrocellulosic derivative. After coating this composition on a sheet of paper and drying, when an intaglio printing is carried out, the iridescent composition is transferred to the printing plates.
• Example 1 The composition of Example 1 is produced, but a binder based on poly (vinylidene chloride) is used. By depositing a layer of this composition on paper, then drying, an intaglio printing can be carried out without any transfer of the composition onto the printing plates.
• a binder based on poly vinylene chloride
• Example 1 The composition of Example 1 is produced, but a binder based on polyurethane in aqueous solution is used. By depositing a layer of this composition on paper, then drying, an intaglio printing can be carried out without any transfer of the composition onto the printing plates.

Landscapes

• Credit Cards Or The Like (AREA)
• Printing Methods (AREA)
• Accessory Devices And Overall Control Thereof (AREA)
• Paper (AREA)
• Cleaning In Electrography (AREA)
• Laminated Bodies (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=9403567

Family Applications (1)

Country Status (7)

Cited By (5)

Families Citing this family (1)

Citations (4)

Family Cites Families (1)

• 1990
  • 1990-12-21 FR FR9016142A patent/FR2670812B1/fr not_active Expired - Lifetime
• 1991
  • 1991-12-20 MX MX9102732A patent/MX9102732A/es not_active IP Right Cessation
  • 1991-12-20 DK DK91403501T patent/DK0493231T4/da active
  • 1991-12-20 AT AT91403501T patent/ATE122425T1/de not_active IP Right Cessation
  • 1991-12-20 DE DE69109647T patent/DE69109647T3/de not_active Expired - Lifetime
  • 1991-12-20 ES ES91403501T patent/ES2072580T5/es not_active Expired - Lifetime
  • 1991-12-20 EP EP91403501A patent/EP0493231B2/de not_active Expired - Lifetime

Patent Citations (4)

Non-Patent Citations (1)

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