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
• • 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
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
  • D21H17/42—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups anionic
• • 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
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
  • D21H17/42—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups anionic
  • D21H17/43—Carboxyl groups or derivatives thereof
• • 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
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
  • D21H17/44—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups cationic
• • 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
  • D21H21/18—Reinforcing agents
• • 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
  • D21H21/18—Reinforcing agents
  • D21H21/20—Wet strength agents
• • 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
  • D21H21/42—Ribbons or strips
• • 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
  • D21H5/00—Special paper or cardboard not otherwise provided for
  • D21H5/26—Special paper or cardboard manufactured by dry method; Apparatus or processes for forming webs by dry method from mainly short-fibre or particle material, e.g. paper pulp
  • D21H5/265—Treatment of the formed web
  • D21H5/2657—Consolidation
  • D21H5/2664—Addition of a binder, e.g. synthetic resins or water

Definitions

• the invention relates to a method of manufacturing a crush resistant security sheet and a security document comprising the sheet.
• the object of the present invention is therefore to provide a method of manufacturing a security sheet which has a good resistance to wrinkling.
• a wrinkle-resistant security sheet comprising fibers, an anionic polymer in a proportion of between 5 and 45% by dry weight relative to the total weight of the dry fibers and having a temperature. glass transition greater than - 40 ° C and a main cationic flocculating agent in an amount of between 1 and 5% by dry weight relative to the total weight of the fibers in dry.
• the process of the invention makes it possible, by using an anionic polymer and flocculating agent (s), to precipitate said anionic polymer on the fibers and to obtain a security sheet having resistance properties. wrinkling particularly high.
• total fiber weight should be understood as meaning “total dry fiber weight” unless otherwise indicated.
• anionic polymer is meant here a polymer having anionic groups. This polymer was used in the form of a dispersion or an emulsion in a stabilized aqueous medium, also called latex. Polymers in aqueous dispersion are commonly used and known to those skilled in the paper industry.
• said aqueous suspension further comprises a secondary cationic flocculating agent in an amount of between 0.001 and 0.006% by dry weight relative to the total weight of the fibers.
• said formed sheet further comprises a secondary cationic flocculating agent in an amount of between 0.001 and 0.006% by dry weight relative to the total weight of the fibers.
• a secondary cationic flocculating agent in an amount of between 0.001 and 0.006% by dry weight relative to the total weight of the fibers.
• said aqueous suspension is obtained from a fiber mixture and from said main cationic flocculating agent, to which said anionic polymer and said cationic flocculating agent are added. secondary before proceeding to the formation of said sheet.
• This embodiment has the advantage that it can be applied to aqueous suspensions of "standard" fibers used for the manufacture of safety sheets because they comprise wet strength agents which can also be used as flocculation agents. in the context of the present invention.
• said anionic polymer is added before said secondary flocculation agent.
• the Applicant has found that the presence of an anionic polymer and flocculating agent (s) in the composition of the sheet formed according to the method of the invention significantly improved the crease resistance of said sheet.
• the sheet formed according to the method of the invention may have a porosity after crumpling close to that of an uncrumpled sheet, that is to say that the folds caused by crumpling substantially do not weaken the paper. This feature allows the security sheet formed according to the invention to have a very high circulation time.
• the sheet formed according to the process of the invention also has a very high double-fold resistance.
• the sheet formed according to the method of the invention has a tear strength equivalent to or greater than that of a similar sheet free of anionic polymer.
• said anionic polymer present in the composition of the formed sheet has a glass transition temperature of between -30 ° C. and 10 ° C.
• glass transition temperature means the temperature below which the polymer is rigid. As the temperature increases, the polymer passes through a transition state that allows the macromolecular chains to slip relative to one another and the polymer softens.
• the proportion of said anionic polymer in the composition of the sheet is between 10 and 30% by dry weight relative to the total weight of the fibers.
• the fibers used in the composition of the sheet comprise cellulosic fibers, in particular cotton fibers.
• said cellulosic fibers are present in a proportion greater than 60% by dry weight relative to the total dry weight of the composition of the sheet.
• said cellulosic fibers represent at least 70% by dry weight of the total amount of fibers.
• said cellulosic fibers are cotton fibers and represent at least 70% by dry weight of the total amount of fibers.
• the fibers used in the composition of the sheet may comprise synthetic fibers.
• This embodiment is particularly advantageous because it makes it possible to further improve the tear-resistance properties of the sheet according to the invention.
• the Applicant has found that, surprisingly, the use of synthetic fibers, generally used to strengthen the paper, had a synergistic effect with the use of the anionic polymer.
• the Applicant has measured that the sheets containing synthetic fibers, while maintaining a high wrinkle resistance, also had a particularly high tear resistance.
• the tear resistance of the sheets according to this particular embodiment of the invention is greater than the tear resistance of the sheets according to the invention without synthetic fibers and the tear resistance of sheets comprising synthetic fibers. but no anionic polymer.
• the synthetic fibers are in a proportion of between 5 and 30% by dry weight relative to the total weight of the fibers.
• the sheet comprises cotton fibers in a proportion of at least 70% by dry weight relative to the total weight of the fibers and synthetic fibers in a proportion of between 10 and 30% in dry weight relative to the total weight of the fibers, the sum total of cotton fibers and synthetic fibers being equal to 100.
• the security sheets formed according to the process of the invention comprising synthetic fibers have a tear strength greater than 1300 mN.
• said synthetic fibers are chosen from polyamide fibers and / or polyester fibers. They may be, for example, polyamide 6-6 fibers or polyester fibers marketed by Kuraray under the trade name EP133.
• the anionic polymer present in the security sheet comprises a polymer having carboxyl functions.
• said polymer is a carboxylated syrene-butadiene copolymer.
• Such copolymers are available, for example, from Dow Chemical Company with different glass transition temperatures.
• the main cationic flocculating agent is a cationic resin.
• this resin is a polyamide-amine-epichloridin resin, called PAAE resin.
• the main cationic flocculating agent is chosen from polyacrylamides, polyethyleneimines, polyvinylamines and their mixtures.
• the secondary cationic flocculating agent is chosen from polyacrylamides, polyethylenimines, polyvinylamines and their mixtures.
• the security sheet comprises at least one security element.
• said security element is chosen from optically variable devices (OVD), in particular interferential elements, in particular iridescent elements, holograms, security threads, watermarks, boards, pigments or luminescent fibers. and / or magnetic and / or iridescent and / or metallic, and combinations thereof.
• ODD optically variable devices
• interferential elements in particular iridescent elements, holograms, security threads, watermarks, boards, pigments or luminescent fibers.
• iridescent elements in particular iridescent elements, holograms, security threads, watermarks, boards, pigments or luminescent fibers. and / or magnetic and / or iridescent and / or metallic, and combinations thereof.
• the sheet according to the invention may comprise an RFID device (radio frequency identification device).
• the security sheet comprises at least one at least partially fiber-free zone, also known as a "window" zone.
• the security sheet according to the invention comprises a thread or a security band incorporated into said sheet, and appearing in at least one window.
• the security sheet comprises mineral fillers in an amount of 1 to 10% by dry weight relative to the total weight of the fibers.
• said mineral fillers are present in a proportion of between 1 and 5% by dry weight relative to the total weight of the fibers.
• These fillers are chosen, for example from calcium carbonate, kaolin and titanium dioxide, or mixtures thereof.
• the method of manufacturing the security sheet comprises a step in which at least one face of said sheet, after dewatering of said suspension is coated with a surfacing layer.
• This surfacing layer may make it possible, for example to improve the bending and / or tensile strength properties or even the durability properties of said sheet, as described below.
• the formed security sheet may further comprise an outer surfacing layer.
• These surfacing layers, coated on at least one side of a sheet, are well known to those skilled in the art and allow, for example for a layer based on a polyvinyl alcohol to improve the double-fold resistance properties. and pulling the sheet.
• the security sheet formed according to the method of the invention may comprise a surfacing layer intended to reinforce its durability properties, such as that for example a layer whose composition is described in the application EP 1 319 104 and which comprises a transparent or translucent elastomeric binder, such as a polyurethane, and a colloidal silica.
• the invention also relates to a security document comprising the security sheet as obtained by the method described above.
• the invention relates to a banknote.
• the Applicant has carried out three series of tests: the series 1 and 2 on non-surfaced sheets and the series 3 on sheets coated with a surfacing layer, as are generally the sheets included in the security documents such as than banknotes.
• a security sheet is produced whose composition corresponds to the basic composition of a large number of banknotes currently in circulation.
• said sheet is formed wet on a paper machine of round shape, from an aqueous suspension comprising only cotton fibers and a wet strength agent (here a PAAE resin) in a proportion of 2.1% by dry weight relative to the weight of the fibers.
• a wet strength agent here a PAAE resin
• the resulting sheet has a basis weight of 85.2 g / m 2 , and a thickness of 142 microns.
• a sheet formed according to the process of the invention comprising cotton-only fibers, a carboxylated styrene-butadiene copolymer with a glass transition temperature of -25 ° C., is produced on a paper machine of round shape. a proportion of 11% by dry weight relative to the weight of the fibers and a main flocculation agent in the form of a PAAE resin in a proportion of 2.3% by dry weight relative to the total weight of the fibers.
• the PAAE resin also has a role of wet strength agent, as in Comparative Example 1.
• the resulting sheet has a basis weight of 87.6 g / m 2 and a thickness of 124 microns.
• a sheet of paper formed according to the process of the invention is made by taking up the composition of Example 2 and adding a polyacrylamide as a secondary flocculating agent in a proportion of 0.001% relative to the total weight of the fibers.
• the resulting sheet has a basis weight of 86.9 g / m 2 and a thickness of 125 microns.
• the resulting sheet has a basis weight of 86.5 g / m 2 and a thickness of 121 microns.
• a security sheet is produced whose composition corresponds to the basic composition of a large number of banknotes currently in circulation.
• said sheet is formed wet on a laboratory form, from an aqueous suspension of cotton-only fibers comprising a wet strength agent (here a PAAE resin) in a proportion of 2.5% by dry weight relative to the total weight of the fibers.
• a wet strength agent here a PAAE resin
• the resulting sheet has a basis weight of 80.5 g / m 2 , and a thickness of 137 microns.
• a sheet of paper formed according to the process of the invention comprising cotton-only fibers, a carboxylated styrene-butadiene copolymer having a glass transition temperature of 5 ° C in an amount of 25% by dry weight relative to the total weight of the fibers, a PAAE resin as main flocculating agent (also having a role of wet strength agent) in a proportion of 3.1% by dry weight relative to to the total weight of fibers and a polyacrylamide as a secondary flocculating agent in a proportion of 0.003% by dry weight, relative to the total weight of the fibers.
• the resulting sheet has a basis weight of 82.7 g / m 2 , and a thickness of 132 microns.
• a sheet of paper formed according to the process of the invention comprising cotton-only fibers, a carboxylated styrene-butadiene copolymer having a glass transition temperature of 5 ° C in an amount of 11% by dry weight relative to the total weight of the fibers, a PAAE resin as main flocculation agent (also having a role of wet strength agent) in a proportion of 2.8% by dry weight relative to to the total weight of fibers and a polyacrylamide as a secondary flocculating agent in a proportion of 0.002% by dry weight, based on the total weight of the fibers.
• the resulting sheet has a basis weight of 83.4 g / m 2 and a thickness of 136 microns.
• a wet sheet is formed on a round paper machine from an aqueous suspension of cotton-only fibers comprising a wet strength agent (PAAE resin) in a proportion of 2.1. % by dry weight relative to the total weight of the fibers.
• PAAE resin wet strength agent
• the sheet of paper obtained is coated with a surfacing layer, intended to improve the durability of the sheet, comprising a polyurethane binder and a colloidal silica, as described in the application EP 1 319 104 .
• the resulting sheet has a basis weight of 85.8 g / m 2 , and a thickness of 97 microns.
• a security sheet is made comprising the same constituents as in Comparative Example 8, but part of the cotton fibers have been replaced by polyamide fibers so that the proportion of cotton fibers is 85% by dry weight. and the proportion of polyamide fibers is 15% by dry weight relative to the total weight of the fibers in dry.
• a sheet of paper according to the process of the invention comprising cotton-only fibers, is formed on a round paper machine, a carboxylated styrene-butadiene copolymer having a glass transition temperature of -26 ° C. a proportion of 11% by dry weight relative to the total weight of the fibers in dry state and a PAAE resin as main floculation agent (also having a role of wet strength agent) in a proportion of 2.3% in dry weight relative to the total weight of fibers in dry.
• the resulting sheet has a basis weight of 92.8 g / m 2 and a thickness of 103 microns.
• a sheet of paper according to the process of the invention comprising cotton-only fibers, is formed on a round paper machine, a carboxylated styrene-butadiene copolymer having a glass transition temperature of -26 ° C. an amount of 11% by dry weight relative to the total weight of the fibers, a PAAE resin as main flocculating agent in a proportion of 2.1% by dry weight relative to the total weight of fibers in dry and a polyacrylamide as agent of secondary flocculation in a proportion of 0.001% by dry weight relative to the total weight of the fibers in dry.
• the resulting sheet has a basis weight of 86.9 g / m 2 and a thickness of 100 microns.
• a paper sheet is formed according to the process of the invention, comprising only cotton fibers, a carboxylated styrene-butadiene copolymer having a glass transition temperature of -26 ° C. to 25% by dry weight relative to the total weight of the dry fibers, a PAAE resin as main flocculating agent (also having a role of wet strength agent) in an amount of 2.6% by weight. dry weight relative to the total weight of dry fibers and polyacrylamide as a secondary flocculating agent in a proportion of 0.004% by dry weight relative to the total weight of the fibers in dry.
• the resulting sheet has a basis weight of 82.9 g / m 2 and a thickness of 95 microns.
• a sheet of paper is formed according to the process of the invention by taking up the composition of Example 12, but replacing a portion of the cotton fibers with polyamide fibers so that the proportion of polyamide fibers is 15% by weight relative to the total weight of the fibers in dry.
• the resulting sheet has a basis weight of 85.4 g / m 2 and a thickness of 108 microns.
• the porosity measurements before and after creasing (8 wrinkles at each test) are performed according to standard NF Q03-076. Wrinkles are made by a device of the brand IGT "NBS Crumpling Device”.
• the double-fold resistance measurements are carried out according to the ISO 5626 standard.
• the double fold resistance is greatly increased compared to the sheet of Comparative Example 1 (increase between 16 and 53%).
• the sheets according to Examples 6 and 7 formed according to the process of the invention have substantially improved after-creasing porosities compared with Comparative Example 5 taken as a reference (decrease between 17 and 48% of the porosity after creasing).
• the double fold resistance is greatly increased compared to the sheet of Comparative Example 5 taken as a reference (increase between 87 and 122%).
• the sheets formed according to the process of the invention of Examples 10 to 13 show an improvement, relative to the sheet free of anionic polymer of Comparative Example 8 taken as a reference, of between 27% and 186%.
• the sheet of Comparative Example 9 does not include anionic polymer but comprises polyamide fibers in a proportion of 15%.
• the tear strength of the sheet of Comparative Example 8 is 13% lower than that of the sheet of Comparative Example 2, which confirms the effect of the synthetic fibers.
• Examples 10 to 12 show tearing values lower than or equal to those of Comparative Example 8 and lower than those of Comparative Example 9, ie the presence of an anionic polymer alone. has no beneficial influence on the tear strength.
• Example 13 has a higher tear strength value than that of Comparative Example 8, but is also significantly higher (+ 59%) than that of Comparative Example 9. It follows that the combination of presence of synthetic fibers and anionic polymer in the composition of the security sheet has a synergistic effect on the tear strength of said sheet.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Paper (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Cleaning In Electrography (AREA)
• Laminated Bodies (AREA)
• Developing Agents For Electrophotography (AREA)

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• 2007
  • 2007-05-31 FR FR0755382A patent/FR2916768B1/fr active Active
• 2008
  • 2008-05-28 EP EP08805868.0A patent/EP2148954B2/fr active Active
  • 2008-05-28 UA UAA200912238A patent/UA96190C2/ru unknown
  • 2008-05-28 US US12/599,219 patent/US10023998B2/en active Active
  • 2008-05-28 PL PL08805868T patent/PL2148954T5/pl unknown
  • 2008-05-28 RU RU2009143616/12A patent/RU2485237C2/ru active
  • 2008-05-28 DE DE08805868T patent/DE08805868T1/de active Pending
  • 2008-05-28 SI SI200831123T patent/SI2148954T1/sl unknown
  • 2008-05-28 BR BRPI0812055-2A patent/BRPI0812055B1/pt active IP Right Grant
  • 2008-05-28 CA CA002688172A patent/CA2688172A1/fr not_active Abandoned
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  • 2008-05-28 CN CN2008800167229A patent/CN101711297B/zh active Active
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  • 2008-05-28 WO PCT/FR2008/050924 patent/WO2008152299A2/fr not_active Ceased
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