USE OF EPOXY-SILICONE COPOLYMER, CROSS-CROSS-COATED FLOWABLE COMPOSITION CONTAINING IT AND A BANK NOTE COATED WITH SAID COMPOSITION

Claims

1. The use of an epoxy-silicone copolymer, i.e. polyorganosiloxane provided with branches containing epoxy functional groups, for the production of a surface coating for banknotes that has writing resistance.

2. The use according to claim 1, wherein said polyorganosiloxane corresponds to one of the following formulas: and in these formulas: R represents hydrocarbon groups that are identical or different from each other, R 1 represents a hydrogen atom or hydrocarbon groups that are identical or different from each other, R 2 represents a hydrocarbon group containing at least one carbon atom, wherein the group may also contain an oxygen atom, n ≥ 1 and m ≥ 1, n > m, and m are integers, R 3represents a hydrocarbon group containing at least one carbon atom; X represents a carbon atom, its index o is greater than or equal to 0.

3. The use according to claim 1, wherein said polyorganosiloxane corresponds to one of the following formulas and in these formulas: R 4 represents a methyl or methylene substituent that forms a bridge within cyclohexyl and is chemically stable, in this case, the combination of formula (b) and formula (c') is excluded.

4. The use according to claim 3, wherein said polyorganosiloxane corresponds to formula (c).

5. A flowable composition capable of crosslinking under the influence of ultraviolet radiation, characterized in that it contains a cationic crosslinking matrix, as well as an epoxy-silicone copolymer, i.e. polyorganosiloxane provided with branches containing epoxy functional groups.

6. The composition according to item 5, characterized in that the said polyorganosiloxane corresponds to one of the following formulas: and in these formulas: R represents hydrocarbon groups that are identical or different from each other, R 1 represents a hydrogen atom or hydrocarbon groups that are identical or different from each other, R 2 represents a hydrocarbon group containing at least one carbon atom, wherein the group may also contain an oxygen atom, n ≥ 1 and m ≥ 1, n > m, n and m are integers, R 3 represents a hydrocarbon group containing at least one carbon atom; X represents a carbon atom, its index o is greater than or equal to 0.

7. The composition according to item 6, characterized in that the said polyorganosiloxane corresponds to one of the following formulas: and in these formulas: R 4 represents a methyl or methylene substituent that forms a bridge within cyclohexyl and is chemically stable, in this case, the combination of formula (b) and formula (c') is excluded.

8. The composition according to any one of claims 5 or 7, characterized in that the cationic crosslinking matrix contains a cycloaliphatic diepoxide, preferably in an amount of at least 50% by weight.

9. The composition according to one of claims 5 to 8, characterized in that said polyorganosiloxane is present in an amount of at least 5% by weight, preferably from 5 to 15% and even more preferably from 8 to 12%.

10. A composition according to any one of paragraphs 5-9, characterized in that it additionally contains perfluoropolyether (PFPE)-tetraurethane acrylate in a mixture with ethyl acetate and butyl acetate.

11. The composition according to claim 10, characterized in that said PFPE tetraurethane acrylate is present in an amount of at least 0.5% by weight, preferably from 0.5 to 5%, and even more preferably from 2 to 4%.

12. A banknote, characterized in that at least one of its opposite sides has a surface coating that resists writing, formed from a composition according to any of paragraphs 6-11, which is cross-linked under the influence of ultraviolet radiation.

13. A banknote according to the preceding paragraph, characterized in that said surface coating having write resistance has a write resistance rating greater than 8.5 if said at least one side is printed by intaglio printing or calendered, or otherwise greater than 4.5, preferably greater than 10 if said at least one side is printed by intaglio printing or calendered, or otherwise greater than 6, and more preferably greater than 13 if said at least one side is printed by intaglio printing or calendered, or otherwise greater than 9.