Classifications

• • 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
• • 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
  • D21H21/44—Latent security elements, i.e. detectable or becoming apparent only by use of special verification or tampering devices or methods
  • D21H21/46—Elements suited for chemical verification or impeding chemical tampering, e.g. by use of eradicators

Definitions

• the present invention relates to the problem posed by the risk of falsification attached to the use of a ballpoint pen with ink erasable by erasing or scraping.
• ballpoint pen inks are mainly composed of mineral pigments with remarkable stability and unassailable properties.
• these inks have the disadvantage of not easily lending themselves to corrections, unless using aggressive technical means which leave an indelible mark or mark on the written medium.
• the ink can be considered to include, in its composition , a first type of rapid solvent used to immediately hang the colored pigments on the support, so as to establish a material fixation on the support.
• the ink also contains a second solvent which can be described as slow and whose evaporation leads to the intimate bond between the binders of the colored pigments and the surface layer of the support. As long as the second solvent is not completely evaporated, the colored pigments can be erased by rubbing, such as scraping or, more particularly, scrubbing.
• a ballpoint pen loaded with an ink of the above type allows successive corrections for a given period of time and facilitates, for example, the execution of documents or printed matter of a current character.
• German application published before examination 29 51 486 proposes, in this sense, the incorporation into the constituent mass of the printing-writing medium, of microencapsulated dyes and of an acid silicate acceptor of dyes. Under the pressure generated by the tip of a pen used to write on such a support, the capsules are punctured and release the dye which reacts with the acid silicate to form a trace in the mass of the support.
• any attempt at falsification to eliminate the trace of the ink specific to the ballpoint pen, lets appear the internal mark on the paper which then represents the physical trace of an attempt at falsification. If such an attempt is made by means of an eraser strongly supported on the support, the locally exerted pressure develops, over the entire surface concerned, a mark further increasing the proof of attempted falsification.
• European patent application 0 029 714 proposes using, by coating on a print-write support, a film of adsorbent products, electron acceptors, such as a silica gel or a reactive kaolin.
• French patent application 80-11,124 (2,483,480) relates to a security paper comprising micro-capsules on the surface containing an ink solvent of the type of that taught by American patent 4,097,290.
• Micro-capsules punctured during the application of pressure by the tip of the pen, release the solvent they contain, which dilutes, at least in part, the ink of the pen and carries inorganic pigments into the surface layer.
• a paper or print-writing medium, produced according to this technique is relatively high cost, taking into account the need to micro-encapsulate the solvent responsible for the subsequent dilution of the ink.
• the colored mark is affixed on an area or surface whose microcapsules have already been punctured.
• the function of these microcapsules can no longer intervene, since the solvent is already diluted or evaporated.
• French patent 81-18 794 (2 491 968) proposes a security paper associated in mass or on the surface with micro-capsules containing a solvent to dissolve the dye used for registration.
• the present invention aims to provide a solution to the problem thus posed by the existence of inks and stylobilles of the type described in US Pat. No. 4,097,290, by proposing a support eliminating any possibility of erasing the ink immediately after its deposit.
• Another object of the invention is to provide a new support that can be produced at a very attractive price and that presents no risk of partial deterioration of its function, during the manufacturing, handling, storage, trimming, bundling, etc. phases. ..
• Yet another object of the invention is to provide a print-write support which can be made up of superimposed bundles, without the risk of successive reproductions on the lower or underlying supports of the information printed or written on the first accessible support.
• a further object of the invention is to propose a new support making it possible to combine the effects of the object of the invention with other known treatments, to confer additional characteristics of tamper-proofing, such as the appearance of colored reactions via commercial solvents or chemical reagents or erasers.
• the object of the invention is characterized in that it comprises a substrate associated, at least on the surface, with mineral or organic products having an absorbent power equivalent to an oil uptake at less equal to 150 g per hundred grams of product, oil intake measured according to the NF T 30 022 method (or ISO 787/5/1980).
• the object of the invention is based on the use of the remarkable absorbent properties of certain mineral or organic products and, more particularly, those characterized by an absorbent capacity equivalent to an oil uptake at least equal to 150 g per hundred grams. of product, oil intake measured or evaluated according to the NF T 30 022 method (or ISO 787/5/1980).
• the absorbent products are also chosen from those characterized by a very high specific surface greater than 20 m 2 / g, measured according to the BET method (BRUNAUER, EMMETT and TELLER, J. AM. CHEM SOC. 60 , 309 (1938)).
• Absorbent products meeting these two characteristics can be used by being incorporated into the mass or coated by coating on the surface of the support.
• all the supports usually usable in printing-writing can be associated with the absorbent product according to the invention, that is to say the plastic films and the sheets of fibers of more or less cellulosic origin obtained by paper or any other process.
• a support according to the invention has an inert nature and is insensitive to external agents, as well as to thermal or climatic modifications.
• such a support is insensitive to the pressure constraints that can be applied during manufacture, storage, handling, guillotage, bundling, etc. during which it does not undergo any capacity destruction that 'it conceals.
• Another advantage of the invention lies in the fact that such a support can be treated by incorporation, in the mass or on the surface, at a low cost, since the treatment of such a support can be carried out by the usual manufacturing and / or surfacing-coating techniques.
• These products can be introduced into the mass during the preparation of the constituent material of the plastic film or of the paper pulp, as is usually practiced in this field as regards the mineral fillers introduced into the pulp. The ratio can then be between 5 and 20% by weight remaining in the support.
• These products can also be deposited by surfacing or coating on one of the faces of a substrate, such as a plastic film or a sheet of paper, at a rate of 1 to 10 g / m. This deposition can occur during the manufacture of the substrate or by a clean operation, outside of manufacture, by the means usually used to make a surfacing or coating of a substrate.
• the product or products with a high absorption power enter, for the essential part, in the composition of the coating, by being associated with the usual binders, such as starches, starches and their derivatives or other binders used and known in the art for coating or surfacing.
• binders such as starches, starches and their derivatives or other binders used and known in the art for coating or surfacing.
• additional fillers usually used, for example in stationery, to improve the deposition conditions, the cohesion, the fineness, the color, etc. ..
• a substrate constituted by a paper and intended to represent a falsifiable printing-writing medium.
• a mineral product with high absorbency such as a precipitated aluminum silicate, for example that known commercially as "Pasilex” sold by the company DEGUSSA, is incorporated into the paper pulp before passing through the machine. rate of 15 X remaining in the paper after manufacture.
• the product "Pasilex” is chosen from the range having an absorbent power equivalent to an oil intake of 160 g per 100 g of product and offering a specific surface of 100 m 2 / g calculated according to the BET method (BRUNAUER, EMMETT and TELLER, J. AM. CHEM. SOC., 60, 309 (1938)).
• This sauce is applied by a size press, on a paper machine, to the surface of a sheet of support paper of 93 g / m 2 , so as to deposit 2 to 5 g of dry matter of the sauce per square meter.
• This sauce is applied in conventional coating, for example by means of a dragging coater, so as to deposit from 1 to 5 g of dry matter per square meter of surface.
• Examples 2 and 3 above can be used for a substrate constituted, for example, by an opaque oriented polypropylene film, for example in the case of application to credit cards, to identity cards.
• the print-write support thus obtained has normal printability characteristics and prohibits any attempt at falsification by friction, in particular by scrubbing, of a mark made with a ballpoint pen of the type of that of American patent 4 097 280 or of a type. neighbor, but leading to the same result, and comprising an ink, said to be erasable for a certain time corresponding, for example, to the duration of evaporation of a slow solvent.
• Such a print-write medium can also include a tamper-proofing treatment using chemical compounds giving colored reactions with solvents, acids, bases, oxidants, reducers, etc.
• the object of the invention finds a particularly advantageous application in the field of security papers or documents of value, such as checks, commercial paper, as well as support documents or other means of identification of a personal nature, such as credit cards, toll pass cards, ID cards, etc.

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

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Cited By (2)

Citations (7)

• 1984
  • 1984-12-05 FR FR8418791A patent/FR2574099B1/fr not_active Expired
• 1985
  • 1985-12-02 DE DE8585420214T patent/DE3562104D1/de not_active Expired
  • 1985-12-02 AT AT85420214T patent/ATE33410T1/de not_active IP Right Cessation
  • 1985-12-02 EP EP85420214A patent/EP0184529B1/de not_active Expired

Patent Citations (7)

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