Information medium having antiviral properties, and method for making same

Abstract

The present invention relates to an information medium to be handled by a large number of users, such as a banknote, and having antiviral properties, and to a method for making same.

Claims

1. A method for producing an information medium having antiviral activity, the method comprising: in the presence of a catalyst, depositing on a surface of a substrate medium an aqueous composition comprising at least lauric acid and glycerol, the substrate medium comprising paper, and the catalyst selected from the group consisting of a zeolite catalyst and a lipase catalyst; and subsequent to depositing the aqueous composition and in the presence of the catalyst, heating the substrate medium with the aqueous composition deposited thereon, wherein the heating: comprises subjecting the substrate medium to a temperature of approximately 80° C. to approximately 100° C., synthesizes monolaurin, in situ on the substrate medium, from the lauric acid and glycerol, and dries the substrate medium and the monolaurin synthesized thereon.

2. The method of claim 1, wherein the catalyst is present in the substrate medium prior to deposition of the aqueous composition.

3. The method of claim 1, wherein the catalyst is present in the aqueous composition prior to deposition of the aqueous composition.

4. The method of claim 3, wherein the catalyst is present in the aqueous composition in a proportion of at least 2% by weight relative to a total weight of the lauric acid and the glycerol.

5. The method of claim 1, wherein heating the substrate medium comprises subjecting the substrate medium to a temperature of approximately 90° C. to approximately 100° C.

6. The method of claim 5, wherein heating the substrate medium comprises subjecting the substrate medium to a temperature of approximately 100° C.

7. The method of claim 1, wherein the glycerol is in molar excess over the lauric acid.

8. The method of claim 1, further comprising, prior to deposition of the aqueous composition, forming the substrate medium.

9. The method of claim 8, further comprising introducing the catalyst into the substrate medium during the formation of the substrate medium.

10. The method of claim 1, wherein the information medium produced has an antiviral activity of greater than 1 log.

11. The method of claim 1, wherein the substrate medium comprises a security element chosen from one or more of a security thread, a watermark, a pattern, a patch, a foil, a planchette, a strip, a printed thread, a metalized thread, and a particle.

12. The method of claim 11, wherein the security element is detectable using one or more of ultraviolet radiation, infrared radiation, visible light, electricity, and magnetism.

13. The method of claim 1, wherein the substrate medium comprises cellulose fibers.

14. The method of claim 1, wherein the substrate medium comprises cotton fibers.

Description

EXAMPLES

Comparative Example 1

(1) A sheet of paper is formed on a papermaking machine called a cylinder mold with a wire cloth comprising a pattern allowing a watermark to be produced, it being possible for this paper to be suitable as a paper for producing a banknote, in the following manner: a cotton fiber pulp is suspended in water, and this suspension is refined to 60° Schoepper-Riegler, a wet-strength agent is added, approximately 2.5% by dry weight of a poly(aminoamide epichlorohydrin) resin, expressed relative to the cotton fibers, iridescent planchettes are also introduced into this suspension, during the formation of the sheet, a microprinted security thread, called a “window thread” is introduced according to known prior techniques so as to make this thread visible in certain windows at the surface of the paper. One method that can be used to introduce this thread is described, for example, in patent EP 0 059 056, and the sheet is dried at around 100° C.

Example 2

(2) A medium is obtained as in example 1, and is coated with a preparation made in an aqueous medium which comprises: 31.2 parts by dry weight of glycerol, 18.8 parts by dry weight of lactoferrin, 31.2 parts by dry weight of a PVA binder, and 18.8 parts by dry weight of zeolite (zeolite A).

(3) The concentration of lactoferrin relative to the total layering solution is set at 4.7% by weight.

(4) Once coated, the paper comprises a content by dry weight of lactoferrin of approximately 0.98 g/m.sup.2.

Example 3

(5) A medium is obtained as in example 1, and is coated with a preparation made in an aqueous medium which comprises: 31.2 parts by dry weight of glycerol, 18.8 parts by dry weight of lauric acid, 31.2 parts by dry weight of a PVA binder, and 18.8 parts by dry weight of zeolite (zeolite A).

(6) The concentrations of glycerol and of lauric acid relative to the total layering solution are set, respectively, at 6.24 and 3.76% by weight.

(7) Once coated, the paper comprises a content by dry weight of monolaurin of approximately 1.03 g/m.sup.2.

Example 4

(8) A medium is obtained as in example 1, and is coated with a preparation made in an aqueous medium which comprises: 31.2 parts by dry weight of glycerol, 18.8 parts by dry weight of monolaurin, 31.2 parts by dry weight of a PVA binder, and 18.8 parts by dry weight of zeolite (zeolite A).

(9) The concentration of monolaurin relative to the total layering solution is set at 3.76% by weight.

(10) Once coated, the paper comprises a content by dry weight of monolaurin of approximately 1.13 g/m.sup.2.

Example 5

(11) A medium is obtained as in example 1, and is coated with a preparation made in a dispersion of polyurethanes which comprises: 56.4 parts by dry weight of polyurethane, 5.6 parts by dry weight of colloidal silica, 33.8 parts by dry weight of glycerol, 3.8 parts by dry weight of noble laurel essential oil, and 0.4 part by dry weight of emulsifier (fatty alcohol ethoxylate).

(12) The concentration of bay laurel essential oil relative to the total layering solution is set at 1.6% by weight.

(13) The pH of the layering solution is fixed at 8.4.

(14) Once coated, the paper comprises a content by dry weight of noble bay laurel essential oil of approximately 0.19 g/m.sup.2.

Example 6

(15) A medium is obtained as in example 1, and is impregnated with a preparation made in an aqueous medium which comprises: 40 kg of PVA binder,

(16) The PVAs are cured and water is added for a final volume of 950 l; 25 kg of glycerol; 20 kg of lauric acid; 2 kg of zeolite (zeolite A); and 10 l of AMP90.

Tests and Results

1. Anti-Phage Activity

(17) The anti-phage activity test, which is the applicant's own test, is based on modified standard JIS L 1902, or else on modified standard ISO 20743, on MS2 phages, which are reputed to be very resistant, and applied over action times of between 18 and 24 hours.

(18) The principle is the following: MS2 phages are deposited on the test media, and then the number of active MS2 phages is evaluated a first time at t=0 h, and a second time at t=24 h.

(19) In order to evaluate the number of active MS2 phages on the test media at a given time, these media are placed in the presence of particular bacteria which have the property of being hosts for MS2 phages: measurement of the number of lysis plaques (or pfp) after culture then makes it possible to work back to the desired amount of MS2 phages.

(20) It is thus possible to deduce therefrom an anti-phage activity (denoted A), defined as follows:
A=[mean log(C.sub.24)−mean log(C.sub.0)]−[mean log(E.sub.24)−mean log(E.sub.0)],
in which formula, E.sub.24 corresponds to the number of lysis plaques at 24 h and E.sub.0 corresponds to the number of lysis plaques just after it has been brought into contact with the medium tested.

(21) The experimental conditions are the following: The diluent used is peptone/salt (having the Difco reference 1897-17) and the bacterial strain used is Escherichia coli K12, which is a host strain for MS2 phages. The control medium is an untreated 100% cotton textile. 200 μl of a suspension of phages at 1×10.sup.5 pfp/ml are deposited.

(22) The results are reported hereinafter.

Examples 2 to 4

(23) TABLE-US-00001 Incubation time 0 h 24 h test C.sub.0 Standard mean log C.sub.24 Standard mean log Sample ref. piece (pfp/g) log (C.sub.0) deviation (C.sub.0) (pfp/g) log (C.sub.24) deviation (C.sub.24) Control 1 256 000 5.41 0.07 5.36 38 600 4.59 0.00 4.59 2 207 000 5.32 39 100 4.59 Incubation time 0 h 24 h test E.sub.0 Standard mean log E.sub.24 Standard mean log Sample ref. piece (pfp/g) log (E.sub.0) deviation (E.sub.0) (pfp/g) log (E.sub.24) deviation (E.sub.24) Example 2 1  84 000 4.92 0.01 4.92   800 2.90 0.21 2.75 2  82 000 4.91   400 2.60 Example 3 1 223 000 5.35 0.15 5.24  1 370 3.14 0.08 3.19 2 136 000 5.13  1 760 3.25 Example 4 1  74 000 4.87 0.11 4.95  1 100 3.04 0.08 2.98 2 106 000 5.03   840 2.92

(24) The following anti-phage activities are deduced therefrom:
A.sub.example 2=−0.77−(−2.17)=1.40 log
A.sub.example 3=−0.77−(−2.05)=1.28 log
A.sub.example 4=−0.77−(−1.97)=1.20 log

Example 5

(25) TABLE-US-00002 Incubation time 0 h 24 h test C.sub.0 Standard mean log C.sub.24 Standard mean log Sample ref. piece (pfp/g) log (C.sub.0) deviation (C.sub.0) (pfp/g) log (C.sub.24) deviation (C.sub.24) Control 1 2 728 000 6.44 0.05 6.47   830 000 5.92 0.15 6.02 2 3 160 000 6.50 1 350 000 6.13 Incubation time 0 h 24 h test E.sub.0 Standard mean log E.sub.24 Standard mean log Sample ref. piece (pfp/g) log (E.sub.0) deviation (E.sub.0) (pfp/g) log (E.sub.24) deviation (E.sub.24) Example 5 1 1 735 000 6.24 0.01 6.24   35 000 4.54 0.19 4.68 2 1 772 000 6.25   64 000 4.81

(26) The following anti-phage activity is likewise deduced therefrom:
A.sub.example 5=0.45−(−1.56)=1.11 log.

(27) These tests then consequently demonstrate that the media obtained in accordance with the invention actually exhibit a significant antiviral activity.

Example 6

(28) TABLE-US-00003 Incubation time 0 h 24 h test C.sub.0 Standard mean log C.sub.24 Standard mean log Sample ref. piece (pfp/g) log (C.sub.0) deviation (C.sub.0) (pfp/g) log (C.sub.24) deviation (C.sub.24) Control 1 17 000 4.23 0.12 4.31 5 400 3.73 0.19 3.60 2 25 000 4.40 2 900 3.46 Incubation time 0 h 24 h test E.sub.0 Standard mean log E.sub.24 Standard mean log Sample ref. piece (pfp/g) log (E.sub.0) deviation (E.sub.0) (pfp/g) log (E.sub.24) deviation (E.sub.24) Example 6 1 23 000 4.36 0.00 4.36    0 — — Hetero- 2 23 000 4.36   60 1.78 geneous results

(29) From the values presented above, it may be noted that test piece 1 is totally phagicidal, and the anti-phage activity of test piece 2 can be calculated as follows:
A.sub.example 6=0.71−(−2.58)=1.87 log.

(30) These tests consequently demonstrate that the media obtained in accordance with the invention actually exhibit a significant antiviral activity.

2. Bactericidal/Bacteriostatic Activity

(31) Antibacterial tests were also carried out on the information medium obtained according to example 6, using 2 bacterial strains, namely Staphylococcus aureus CIP 4.83 and Klebsiella pneumoniae 368 CIP.

(32) The bactericidal/bacteriostatic activity test, which is the applicant's own test, is based on standard ISO 20743 and applied over action times of between 18 and 24 hours.

(33) The principle is the following: the bacteria are inoculated by transfer onto the test medium, and then the number of bacterial colonies is measured a first time at t=0 h and a second time at t=24 h.

(34) In order to evaluate the number of bacterial colonies remaining on the test media at a given time, they are counted using a plaque counting method.

(35) It is possible to deduce therefrom the growth value of the tests (denoted G), defined as follows:
F(log.sub.10)=mean log T.sub.t24−mean log T.sub.0

(36) in which formula, T.sub.t24 corresponds to the number of bacterial colonies at 24 h and T.sub.0 corresponds to the number of bacterial colonies just after they have been brought into contact with the medium tested.

(37) The value of the growth of control comparative strains (denoted F) is also determined, and defined as follows:
F(log.sub.10)=mean log C.sub.t24−mean log C.sub.0

(38) in which formula, C.sub.t24 corresponds to the number of bacterial colonies at 24 h and C.sub.0 corresponds to the number of bacterial colonies just after they have been brought into contact with the control medium.

(39) It is thus possible to deduce therefrom the value of the bacterial activity (denoted A), defined as follows:
A(log.sub.10)=F−G

(40) The experimental conditions are the following: The diluent used is peptone/salt (having the Difco reference 218971) and the bacterial strain used is either Staphylococcus aureus CIP 4.83, or Klebsiella pneumoniae 368 CIP. The concentration of the inoculum for Staphylococcus aureus is 3.8×10.sup.5 CFU/ml. The concentration of the inoculum for Klebsiella pneumoniae is 1.23×10.sup.6 CFU/ml. The control medium is an untreated 100% cotton textile.

(41) The results are reported hereinafter.

(42) TABLE-US-00004 Staphylococcus aureus Incubation time 0 h 24 h mean mean test C.sub.0 log log C.sub.t24 log log Sample ref. piece (CFU) (C.sub.0) (C.sub.0) (CFU) (C.sub.t24) (C.sub.t24) Control: 1 36 000 4.56 4.45 23 500 000 7.37 7.42 100% cotton 2 21 600 4.33 29 800 000 7.47 textile Incubation time 0 h 24 h mean mean test T.sub.0 log log T.sub.t24 log log Sample ref. piece (CFU) (T.sub.0) (T.sub.0) (CFU) (T.sub.t24) (T.sub.t24) Example 6 1 52 000 4.72 4.62    1 270 3.10 2.64 2 33 000 4.52      150 2.18

(43) The following antibacterial activity is deduced therefrom:
A(log.sub.10)=4.95.

(44) These tests consequently demonstrate that the media obtained in accordance with the invention can also have, in addition to a significant antiviral activity, a significant bactericidal activity.

(45) TABLE-US-00005 Klebsiella pneumoniae Incubation time 0 h 24 h mean mean test C.sub.0 log log C.sub.t24 log log Sample ref. piece (CFU) (C.sub.0) (C.sub.0) (CFU) (C.sub.t24) (C.sub.t24) Control: 1 45 000 4.65 4.55 16 100 000 7.21 7.10 100% cotton 2 27 900 4.45 10 000 000 7.00 textile Incubation time 0 h 24 h mean mean test T.sub.0 log log T.sub.t24 log log Sample ref. piece (CFU) (T.sub.0) (T.sub.0) (CFU) (T.sub.t24) (T.sub.t24) Example 6 1 57 000 4.76 4.82 0 — — 2 75 000 4.88 0 —

(46) It can be noted that the two test pieces have a bactericidal activity.

(47) These tests consequently demonstrate that the media obtained in accordance with the invention can also have, in addition to a significant antiviral activity, a significant bactericidal activity.

(48) The present examples above are obviously not exhaustive and other basic media and other virucidal agents may be envisioned without departing from the field of protection of the patent.

(49) In particular, the basic medium may be a high-durability security paper which is the subject of patent application FR 2 814 476, a printing/writing paper, tracing paper or a plastic ticket.