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
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/03—Non-macromolecular organic compounds
  • D21H17/05—Non-macromolecular organic compounds containing elements other than carbon and hydrogen only
  • D21H17/06—Alcohols; Phenols; Ethers; Aldehydes; Ketones; Acetals; Ketals
• • 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 invention relates to a security document which cannot be forged by a chemical agent, in particular by sodium sulfite.
• Such documents can be used as bank checks, traveller's checks, titles, notarial acts, etc ... for which it is essential to guard against any chemical falsification of the writings or seals carried on these documents.
• the ink erasing pencils contain sodium sulfite in an alkaline medium, their pH is of the order of 10.
• This alkaline character is used to reveal the falsification by incorporating in mass or on the surface of the document a colored indicator which turns well visibly at a pH of 9.5-10.
• a clearly visible coloration is obtained at a pH of 9.5-10, red with phenolphthalein as described in patent FR-A-2,365,656; a blue coloration is obtained with the AS check dye sold by the company BASF.
• the object of the invention is to provide a security document which cannot be forged by sodium sulfite in particular and which comprises at least one agent sensitive to bases, this agent betraying adulteration with sulfite and which can be chosen from a wide range of compounds in order to to be able to choose a color revealing the falsification which is well contrasted with the color of the final document.
• the object of the invention can be achieved by incorporating in mass and / or on the surface of the document, at least one alkalinity-generating compound under the action of a saturated solution of sodium sulfite. This compound then increases the pH of the document during the falsification attempt and there follows a colored reaction with the agent sensitive to the bases.
• the base-sensitive agent may be a colored indicator or a strong base-sensitive agent such as, for example, manganese chloride.
• R can be any, a carbon chain, saturated or not, linear or branched, contain heteroatoms, one or more rings, heterocycles, aromatic rings.
• Dialdehydes rather than monoaldehydes are preferably used because they generate twice as much alkalinity.
• alkalinity-generating compounds indirectly comprising at least one aldehyde function or at least one ketone function. These compounds are considered to be alkalinity generators according to the invention.
• these may be compounds commonly used as microbicides and which generate formaldehyde; in particular, they may be compounds comprising the methylol group -CH2OH such as hemiformals, sulfur compounds S-methylol or nitrogen compounds N-methylol.
• the invention therefore more particularly provides a document which is characterized in that the alkalinity generator is a compound comprising directly or indirectly at least one aldehyde function or at least one ketone function.
• non-volatile compounds and / or compounds having substantial properties towards the material (for example cellulose) constituting the document to be secured are selected.
• the compounds which have no unpleasant odor and which are well soluble in water are chosen so that their use is simple and to avoid the problems associated with organic solvents (toxicity, risks of explosion. ..).
• aldehyde salycilic aldehyde or a dialdehyde such as glutaric aldehyde can be used in particular.
• These aldehydes are perfectly compatible with the other solvent-reactive infalsification agents, redox agents such as that described in the patent of the Applicant FRA-2,580,303, with chlorinated products (bleach).
• the invention more particularly provides a document containing by mass as a colored indicator the dye for check AS sold by BASF and comprising on the surface of glutaraldehyde and such that it develops a blue coloration under the action of a saturated aqueous solution. in sodium sulfite.
• the invention more particularly provides a document comprising on the surface as a colored indicator of phenolphthalein and also comprising on the surface of glutaraldehyde and such that it develops a red coloration under the action of an aqueous solution saturated with sodium sulfite .
• the invention more particularly provides a document comprising on the surface as an agent sensitive to strong bases of manganese chloride and comprising on the surface of glutaraldehyde and such that it develops a brown coloration under the action of a saturated aqueous solution in sodium sulfite.
• the security document according to the invention can in particular be obtained by the papermaking route from a purely cellulosic fibrous composition or containing synthetic fibers, and optionally containing mineral fillers, dyes and other adjuvants usually used in stationery.
• the document may therefore include other agents reactive to chemical tampering compatible with the alkalinity generator; it can also include physical authentication agents such as watermarks, security threads, boards, fluorescent fibers, iridescent pigments, etc.
• the alkalinity-generating compound can be incorporated en masse during the production of the document. It can also be placed on the surface of the document by coating, printing or impregnating with a size press of the document with a composition containing said compound and a binder and optionally the agent sensitive to bases.
• the quantities of alkalinity-generating compounds and of agents sensitive to the bases will be adjusted by the skilled person according to the intensity of the desired coloring, according to the sensitivity of the compounds and agent reactive to the bases, and also so as not to significantly change the color of the document.
• a sheet is produced by the papermaking route from a cellulosic fibrous composition and possibly other adjuvants.
• This sheet is dried.
• a sheet is produced by the papermaking route from a cellulosic fibrous composition and possibly other adjuvants.
• This sheet is dried.
• the whiteness is 70-85 photovolts.
• a sheet is produced by the papermaking route from a cellulosic fibrous composition to which 0.02 to 0.5% is added on a dry basis relative to the fibrous composition of a colored indicator, the dye for check AS marketed by BASF, and possibly other adjuvants.
• the quantity deposited is approximately 40 g / m2 in dry.
• This sheet is dried.
• a sheet is produced by the papermaking route from a cellulosic fibrous composition and possibly other adjuvants.
• This sheet is dried.
• a sheet is produced by the papermaking route from a cellulosic fibrous composition and possibly other adjuvants.
• This sheet is dried.
• a sheet is produced by the papermaking route from a cellulosic fibrous composition and possibly other adjuvants.
• This sheet is dried.

Landscapes

• Inks, Pencil-Leads, Or Crayons (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=9408627

Family Applications (1)

Country Status (2)

Cited By (4)

Citations (2)

• 1991
  • 1991-01-11 FR FR9100311A patent/FR2671566B1/fr not_active Expired - Fee Related
• 1992
  • 1992-01-10 EP EP19920400058 patent/EP0494828B1/de not_active Expired - Lifetime

Patent Citations (2)

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