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
  • 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
• • 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
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/124—Duplicating or marking methods; Sheet materials for use therein using pressure to make a masked colour visible, e.g. to make a coloured support visible, to create an opaque or transparent pattern, or to form colour by uniting colour-forming components
  • B41M5/165—Duplicating or marking methods; Sheet materials for use therein using pressure to make a masked colour visible, e.g. to make a coloured support visible, to create an opaque or transparent pattern, or to form colour by uniting colour-forming components characterised by the use of microcapsules; Special solvents for incorporating the ingredients

Definitions

• the present invention relates to a new security paper which can be used to prevent forgery when using an erasable ink pen.
• This pen lies in the original composition of its ink specially developed to be able to be erased by conventional mechanical means and more particularly by scrub.
• This new type of easily erasable writing medium represents a definite advantage for current use, but constitutes a danger when it is used to fill in security documents, payment documents: checks or other, all documents in general. likely to be falsified.
• French patent 2,280,154 has already proposed a protection and detection method which consists in using a support covered with a layer.
• the support and the layer having different properties of spectral reflection in the visible, ultraviolet or infrared domains, any alteration of the layer by scratching, or scrubbing, will be detected by an appropriate device.
• the present invention therefore relates to a security paper characterized in that it comprises on at least part of its surface, intended to receive writing, tearable microcapsules containing at least one solvent of the erasable ink.
• microcapsules containing various fluids have been described and used in many technical fields.
• microcapsules will be placed on the surface layer of the paper so as to be effectively torn during writing.
• This surface layer must contain from 30 to 70'70 by weight, relative to the weight of the layer, of microcapsules.
• An insufficient quantity of capsules would not make it possible to sufficiently modify the penetration of the ink into the paper; too large a quantity of capsules would not allow the production of a layer having sufficient mechanical properties.
• the solvents which can be used inside the microcapsules are all the solvents which, in contact with the ink deposited by the pen on the paper, increase the speed of diffusion of the ink inside the paper. Solvents of an aromatic or aliphatic nature or chlorine products or mixtures of these solvents. These solvents may contain a plasticizer such as dioctylphthalate for example.
• the surface layer containing the capsules may cover the whole of one and / or the other side of the paper. This will be the case, for example as described below, when the capsules are integrated into the coating layer (papermaking process) or when a printing process covering the entire surface of the paper is used.
• microcapsule spacer is a product in the form of solid grains (calibrated starch, cellulose powder, etc.) which is mixed with the ingredients forming the coating layer and which in the finished layer disperses between the microcapsules. From 3 to 20% by weight, relative to the weight of the coating layer, of this spacer can be used.
• the other ingredients of the coating layer are known products, in particular a binder, for example starch, PVA, latex, which may be used in an amount of approximately 5 to 20% by weight relative to the weight of the layer, a filler, for example kaolin, carbonate which can be used at a rate of about 15 to 45% by weight relative to the weight of the layer and the various additives known and used for the production of coating layers.
• a binder for example starch, PVA, latex
• a filler for example kaolin, carbonate which can be used at a rate of about 15 to 45% by weight relative to the weight of the layer
• various additives known and used for the production of coating layers are known products, in particular a binder, for example starch, PVA, latex, which may be used in an amount of approximately 5 to 20% by weight relative to the weight of the layer, a filler, for example kaolin, carbonate which can be used at a rate of about 15 to 45% by weight relative to the weight of the layer and the various additives
• the papers according to the invention may also comprise, in their mass and in their coating layer, the known elements which are used or usable to combat counterfeiting.
• the process for carrying out the invention uses any papermaking process which allows the incorporation into the coating layers of microcapsules containing the solvent.
• a layer composed of 10% oxidized starch, 55% capsules containing a solvent of the White-Spirit type with low aromatic contents (such as DILUTINE M5) is deposited, by conventional coating means.
• a solvent of the White-Spirit type with low aromatic contents such as DILUTINE M5
• 12% of calibrated starch serving to distance microcapsules and 23% of kaolin of a coating quality.
• microcapsules are obtained by a known process, the wall being made of a polyurethane.
• These capsules have a diameter of approximately 10 microns.
• the removal required to obtain a good layer according to the invention is approximately 5 to 6 g of layer per square meter.
• the paper thus obtained makes it possible to detect attempts at falsification by scraping or erasing handwritten mentions with an erasable ballpoint pen. Indeed, under the writing pressure the capsules burst and release the solvent. This dilutes the ink, lowers its viscosity, increases its penetration into the support and above all prevents perfect erasure whatever the type of eraser or scraper used. Thus, after an attempt to erase by scrubbing or scraping, there will always remain at least one colored trace of the handwritten mentions due to the penetration of the ink into the support, itself surrounded by a more or less significant colored spot.
• composition of the layer given in Example 1 is used, in which the solvent of the White-Spirit type with low aromatic content is replaced by a solvent of the gasoline type (Essence E from SHELL CHEMISTRY or EXSOL DSP 100-130 from ESSO - CHEMISTRY: boiling point between 100 and 130 ° C).
• Example 2 The composition of the layer given in Example 1 is repeated, in which the capsules containing the solvent of the Nhite-Spirit type with low aromatic content are replaced by a 50/50 mixture of this solvent with di (ethyl ethyl phthalate ). 2 hexyle) (DOP from RHONE POULENC for example).
• Example 1 The composition of the layer given in Example 1 is repeated, in which the 10 micron capsules are replaced by 5 micron diameter capsules containing the same solvent.
• a layer composed of 12% oxidized starch, 46% capsules of 10 micron diameter containing a solvent of the Essence type (Essence E), 9% d is deposited by conventional coating means. calibrated starch and 33% coating kaolin.
• a layer composed of 10% oxidized starch, 11% calibrated starch, 25% kaolin and 54% microcapsules 7 microns in diameter containing a mixture is deposited by conventional coating means.
• a coating layer was deposited at the rate of 5 to 6 g of layer per square meter.
• the behavior of paper, vis-à-vis a writing using erasable ink, is the same as that of the paper described in Example 1.
• composition of the layer given in Example 6 is used using capsules containing a mixture of solvents of the aromatic type (BAYMICRON V.P. FE 2101) 80%, and of the aliphatic type (ISOHEXADECAN BAYER) 20%.
• a layer was deposited at the rate of 6 g / m2.
• the behavior of the paper with regard to writing using erasable ink is the same as that of the paper described in Example 1.
• a layer composed of 9% of a synthetic acrylic binder (ACRONAL S320 from BASF) or based on styrene-butadiene (CA 36034 from BAYER) is deposited by conventional coating means, 23% of kaolin, 12% of calibrated starch and 56% of microcapsules such as those described in Example 6.
• a layer was deposited at the rate of 6 g / m2.
• the behavior of the paper with regard to writing using erasable ink is the same as that of the paper described in Example 1.
• a layer composed of 4.57 of a natural soy protein as a binder is deposited by conventional coating means; PROCOTE 200 LV from PURINA; 24.5% kaolin; 12% of calibrated starch and 59% of microcapsules such as those described in Example 6.
• a coating layer was deposited at a rate of 5 to 6 g / m2.
• the behavior of the paper with regard to writing using erasable ink is the same as that of the paper described in Example 1.
• Example 1 On a mass-bonded support into which the reagents usually introduced in security papers which cannot be forged by chemical agents (dyes for example) have been introduced in mass, the layer given in Example 1 is deposited in which added the reagents usually introduced in a size press (reagents with alkaline agents for example) at the doses necessary to obtain quantities of reagents per square meter identical to those obtained in conventional security papers.
• a size press reagents with alkaline agents for example
• the deposition of 5 to 6 g / m2 of layer makes it possible to obtain a paper which cannot be forged, on the one hand, by acidic, basic, oxidizing, reducing, chemical agents, by oxidizing-reducing couples, by solvents, for the means of classical writing and on the other hand on which the erasable writing means will leave a very visible colored trace after exfoliation or scraping.

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• Paper (AREA)
• Color Printing (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9242417

Family Applications (1)

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Cited By (6)

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Citations (4)

• 1980
  • 1980-05-28 FR FR8011824A patent/FR2483480A1/fr active Granted
• 1981
  • 1981-05-25 EP EP81400825A patent/EP0041024A1/fr not_active Withdrawn
  • 1981-05-27 BR BR8103312A patent/BR8103312A/pt unknown
  • 1981-05-27 ZA ZA00813560A patent/ZA813560B/xx unknown
  • 1981-05-28 JP JP8180681A patent/JPS5721600A/ja active Pending

Patent Citations (4)

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